main: release 0.16.0

Some build tags were duplicated. This commit removes them.

.circleci/config.yml

@@ -28,6 +28,7 @@ commands:
                 qemu-user \
                 gcc-avr \
                 avr-libc
+            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-8-dev
   install-node:
     steps:
       - run:
@@ -44,28 +45,47 @@ commands:
           command: |
             wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
             sudo apt install ./google-chrome-stable_current_amd64.deb
+  install-wasmtime:
+    steps:
+      - run:
+          name: "Install wasmtime"
+          command: |
+            curl https://wasmtime.dev/install.sh -sSf | bash
+            sudo ln -s ~/.wasmtime/bin/wasmtime /usr/local/bin/wasmtime
+  install-xtensa-toolchain:
+    parameters:
+      variant:
+        type: string
+    steps:
+      - run:
+          name: "Install Xtensa toolchain"
+          command: |
+            curl -L https://github.com/espressif/crosstool-NG/releases/download/esp-2020r2/xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz -o xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
+            sudo tar -C /usr/local -xf xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
+            sudo ln -s /usr/local/xtensa-esp32-elf/bin/xtensa-esp32-elf-ld /usr/local/bin/xtensa-esp32-elf-ld
+            rm xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
   llvm-source-linux:
     steps:
       - restore_cache:
           keys:
-            - llvm-source-10-v0
+            - llvm-source-10-v1
       - run:
           name: "Fetch LLVM source"
           command: make llvm-source
       - save_cache:
-          key: llvm-source-10-v0
+          key: llvm-source-10-v1
           paths:
             - llvm-project
   build-wasi-libc:
     steps:
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-v2
+            - wasi-libc-sysroot-v3
       - run:
           name: "Build wasi-libc"
           command: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-v2
+          key: wasi-libc-sysroot-v3
           paths:
             - lib/wasi-libc/sysroot
   test-linux:
@@ -79,6 +99,7 @@ commands:
           llvm: "<<parameters.llvm>>"
       - install-node
       - install-chrome
+      - install-wasmtime
       - restore_cache:
           keys:
             - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -87,15 +108,16 @@ commands:
       - run: go install -tags=llvm<<parameters.llvm>> .
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-systemclang-v1
+            - wasi-libc-sysroot-systemclang-v2
       - run: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-systemclang-v1
+          key: wasi-libc-sysroot-systemclang-v2
           paths:
             - lib/wasi-libc/sysroot
       - run: go test -v -tags=llvm<<parameters.llvm>> ./cgo ./compileopts ./interp ./transform .
       - run: make gen-device -j4
-      - run: make smoketest
+      - run: make smoketest XTENSA=0
+      - run: make tinygo-test
       - run: make wasmtest
       - save_cache:
           key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
@@ -112,7 +134,6 @@ commands:
           command: |
             sudo apt-get install \
                 gcc-arm-linux-gnueabihf \
-                binutils-arm-none-eabi \
                 libc6-dev-armel-cross \
                 gcc-aarch64-linux-gnu \
                 libc6-dev-arm64-cross \
@@ -120,7 +141,11 @@ commands:
                 qemu-user \
                 gcc-avr \
                 avr-libc
+            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-6-dev
       - install-node
+      - install-wasmtime
+      - install-xtensa-toolchain:
+          variant: "linux-amd64"
       - restore_cache:
           keys:
             - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -128,7 +153,7 @@ commands:
       - llvm-source-linux
       - restore_cache:
           keys:
-            - llvm-build-10-linux-v0-assert
+            - llvm-build-10-linux-v1-assert
       - run:
           name: "Build LLVM"
           command: |
@@ -146,7 +171,7 @@ commands:
               make ASSERT=1 llvm-build
             fi
       - save_cache:
-          key: llvm-build-10-linux-v0-assert
+          key: llvm-build-10-linux-v1-assert
           paths:
             llvm-build
       - run: make ASSERT=1
@@ -170,7 +195,6 @@ commands:
           command: |
             sudo apt-get install \
                 gcc-arm-linux-gnueabihf \
-                binutils-arm-none-eabi \
                 libc6-dev-armel-cross \
                 gcc-aarch64-linux-gnu \
                 libc6-dev-arm64-cross \
@@ -178,7 +202,11 @@ commands:
                 qemu-user \
                 gcc-avr \
                 avr-libc
+            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-6-dev
       - install-node
+      - install-wasmtime
+      - install-xtensa-toolchain:
+          variant: "linux-amd64"
       - restore_cache:
           keys:
             - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -186,7 +214,7 @@ commands:
       - llvm-source-linux
       - restore_cache:
           keys:
-            - llvm-build-10-linux-v0
+            - llvm-build-10-linux-v1
       - run:
           name: "Build LLVM"
           command: |
@@ -204,7 +232,7 @@ commands:
               make llvm-build
             fi
       - save_cache:
-          key: llvm-build-10-linux-v0
+          key: llvm-build-10-linux-v1
           paths:
             llvm-build
       - build-wasi-libc
@@ -250,23 +278,25 @@ commands:
             sudo tar -C /usr/local -xzf go1.14.darwin-amd64.tar.gz
             ln -s /usr/local/go/bin/go /usr/local/bin/go
             HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu
+      - install-xtensa-toolchain:
+          variant: "macos"
       - restore_cache:
           keys:
             - go-cache-macos-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
             - go-cache-macos-v2-{{ checksum "go.mod" }}
       - restore_cache:
           keys:
-            - llvm-source-10-macos-v0
+            - llvm-source-10-macos-v1
       - run:
           name: "Fetch LLVM source"
           command: make llvm-source
       - save_cache:
-          key: llvm-source-10-macos-v0
+          key: llvm-source-10-macos-v1
           paths:
             - llvm-project
       - restore_cache:
           keys:
-            - llvm-build-10-macos-v0
+            - llvm-build-10-macos-v1
       - run:
           name: "Build LLVM"
           command: |
@@ -278,17 +308,17 @@ commands:
               make llvm-build
             fi
       - save_cache:
-          key: llvm-build-10-macos-v0
+          key: llvm-build-10-macos-v1
           paths:
             llvm-build
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-macos-v1
+            - wasi-libc-sysroot-macos-v2
       - run:
           name: "Build wasi-libc"
           command: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-macos-v1
+          key: wasi-libc-sysroot-macos-v2
           paths:
             - lib/wasi-libc/sysroot
       - run:
@@ -322,41 +352,48 @@ commands:
       - run:
           name: Create TinyGo user
           command: useradd -m tinygo
-      - run:
-          name: Become TinyGo user
-          command: su tinygo
       - run:
           name: Start SSH Agent
+          user: tinygo
           command: eval $(ssh-agent -s)
       - run:
           name: Add ARCH_RELEASE_SSH_PRIVATE_KEY identity
+          user: tinygo
           command: echo "${ARCH_RELEASE_SSH_PRIVATE_KEY}" | tr -d '\r' | ssh-add -
       - run:
           name: Create SSH directory
+          user: tinygo
           command: mkdir -p ~/.ssh && chmod 700 ~/.ssh
       - run:
           name: Add aur.archlinux.org to known hosts
+          user: tinygo
           command: ssh-keyscan aur.archlinux.org >> ~/.ssh/known_hosts
       - run:
           name: Clone tinygo-bin repo
+          user: tinygo
           command: git clone ssh://aur@aur.archlinux.org/tinygo-bin.git ~/tinygo-bin
       - run:
           name: Update package version
+          user: tinygo
           command: sed -i -E "s/(pkgver=)(.*)$/\1${CIRCLE_TAG}/" ~/tinygo-bin/PKGBUILD
       - run:
           name: Update file checksums
+          user: tinygo
           command: cd ~/tinygo-bin && updpkgsums
       - run:
           name: Update .SRCINFO
+          user: tinygo
           command: cd ~/tinygo-bin && makepkg --printsrcinfo > .SRCINFO
       # Commit the update
       - run:
           name: Set git commit config
+          user: tinygo
           command: |
             git config --global user.email "tinygo-bot@tinygo.org" &&
             git config --global user.name "TinyGo Release Bot"
       - run:
           name: Commit and push changes
+          user: tinygo
           command: |
             cd ~/tinygo-bin &&
             git commit -a -m "Update tinygo-bin to v${CIRCLE_TAG}" &&
@@ -387,6 +424,12 @@ jobs:
     steps:
       - test-linux:
           llvm: "10"
+  test-llvm11-go115:
+    docker:
+      - image: circleci/golang:1.15-buster
+    steps:
+      - test-linux:
+          llvm: "11"
   assert-test-linux:
     docker:
       - image: circleci/golang:1.14-stretch
@@ -418,6 +461,7 @@ workflows:
       - test-llvm10-go112
       - test-llvm10-go113
       - test-llvm10-go114
+      - test-llvm11-go115
       - build-linux
       - build-macos
       - assert-test-linux

.gitignore

@@ -3,6 +3,7 @@ docs/_build
 src/device/avr/*.go
 src/device/avr/*.ld
 src/device/avr/*.s
+src/device/esp/*.go
 src/device/nrf/*.go
 src/device/nrf/*.s
 src/device/nxp/*.go

CHANGELOG.md

@@ -1,3 +1,137 @@
+0.16.0
+---
+
+* **command-line**
+  - add initial support for LLVM 11
+  - make lib64 clang include path check more robust
+  - `build`: improve support for GOARCH=386 and add tests
+  - `gdb`: add support for qemu-user targets
+  - `test`: support non-host tests
+  - `test`: add support for -c and -o flags
+  - `test`: implement some benchmark stubs
+* **compiler**
+  - `builder`: improve detection of clang on Fedora
+  - `compiler`: fix floating point comparison bugs
+  - `compiler`: implement negate for complex numbers
+  - `loader`: fix linkname in test binaries
+  - `transform`: add missing return pointer restore for regular coroutine tail
+    calls
+* **standard library**
+  - `machine`: switch default frequency to 4MHz
+  - `machine`: clarify caller's responsibility in `SetInterrupt`
+  - `os`: add `LookupEnv()` stub
+  - `reflect`: implement `Swapper`
+  - `runtime`: fix UTF-8 decoding
+  - `runtime`: gc: use raw stack access whenever possible
+  - `runtime`: use dedicated printfloat32
+  - `runtime`: allow ranging over a nil map
+  - `runtime`: avoid device/nxp dependency in HardFault handler
+  - `testing`: implement dummy Helper method
+  - `testing`: add Run method
+* **targets**
+  - `arm64`: add support for SVCall intrinsic
+  - `atsamd51`: avoid panic when configuring SPI with SDI=NoPin
+  - `avr`: properly support the `.rodata` section
+  - `esp8266`: implement `Pin.Get` function
+  - `nintendoswitch`: fix crash when printing long lines (> 120)
+  - `nintendoswitch`: add env parser and removed unused stuff
+  - `nrf`: add I2C error checking
+  - `nrf`: give more flexibility in picking SPI speeds
+  - `nrf`: fix nrf52832 flash size
+  - `stm32f103`: support wakeups from interrupts
+  - `stm32f405`: add SPI support
+  - `stm32f405`: add I2C support
+  - `wasi`: add support for this target
+  - `wasi`: use 'generic' ABI by default
+  - `wasi`: remove --no-threads flag from wasm-ld
+  - `wasm`: add instanceof support for WebAssembly
+  - `wasm`: use fixed length buffer for putchar
+* **boards**
+  - `d1mini`: add this ESP8266 based board
+  - `esp32`: use board definitions instead of chip names
+  - `qtpy`: add board definition for Adafruit QTPy
+  - `teensy40`: add this board
+
+0.15.0
+---
+
+* **command-line**
+  - add cached GOROOT to info subcommand
+  - embed git-hash in tinygo-dev executable
+  - implement tinygo targets to list usable targets
+  - use simpler file copy instead of file renaming to avoid issues on nrf52840 UF2 bootloaders
+  - use ToSlash() to specify program path
+  - support flashing esp32/esp8266 directly from tinygo
+  - when flashing call PortReset only on other than openocd
+* **compiler**
+  - `compileopts`: add support for custom binary formats
+  - `compiler`: improve display of goroutine wrappers
+  - `interp`: don't panic in the Store method
+  - `interp`: replace some panics with error messages
+  - `interp`: show error line in first line of the traceback
+  - `loader`: be more robust when creating the cached GOROOT
+  - `loader`: rewrite/refactor much of the code to use go list directly
+  - `loader`: use ioutil.TempDir to create a temporary directory
+  - `stacksize`: deal with DW_CFA_advance_loc1
+* **standard library**
+  - `runtime`: use waitForEvents when appropriate
+* **wasm**
+  - `wasm`: Remove --no-threads from wasm-ld calls.
+  - `wasm`: update wasi-libc dependency
+* **targets**
+  - `arduino-mega2560`: fix flashing on Windows
+  - `arm`: automatically determine stack sizes
+  - `arm64`: make dynamic loader structs and constants private
+  - `avr`: configure emulator in board files
+  - `cortexm`: fix stack size calculation with interrupts
+  - `flash`: add openocd settings to atsamd21 / atsamd51
+  - `flash`: add openocd settings to nrf5
+  - `microbit`: reelboard: flash using OpenOCD when needed
+  - `nintendoswitch`: Add dynamic loader for runtime loading PIE sections
+  - `nintendoswitch`: fix import cycle on dynamic_arm64.go
+  - `nintendoswitch`: Fix invalid memory read / write in print calls
+  - `nintendoswitch`: simplified assembly code
+  - `nintendoswitch`: support outputting .nro files directly
+* **boards**
+  - `arduino-zero`: Adding support for the Arduino Zero (#1365)
+  - `atsamd2x`: fix BAUD value
+  - `atsamd5x`: fix BAUD value
+  - `bluepill`: Enable stm32's USART2 for the board and map it to UART1 tinygo's device
+  - `device/atsamd51x`: add all remaining bitfield values for PCHCTRLm Mapping
+  - `esp32`: add libgcc ROM functions to linker script
+  - `esp32`: add SPI support
+  - `esp32`: add support for basic GPIO
+  - `esp32`: add support for the Espressif ESP32 chip
+  - `esp32`: configure the I/O matrix for GPIO pins
+  - `esp32`: export machine.PortMask* for bitbanging implementations
+  - `esp8266`: add support for this chip
+  - `machine/atsamd51x,runtime/atsamd51x`: fixes needed for full support for all PWM pins. Also adds some useful constants to clarify peripheral clock usage
+  - `machine/itsybitsy-nrf52840`: add support for Adafruit Itsybitsy nrf52840 (#1243)
+  - `machine/stm32f4`: refactor common code and add new build tag stm32f4 (#1332)
+  - `nrf`: add SoftDevice support for the Circuit Playground Bluefruit
+  - `nrf`: call sd_app_evt_wait when the SoftDevice is enabled
+  - `nrf52840`: add build tags for SoftDevice support
+  - `nrf52840`: use higher priority for USB-CDC code
+  - `runtime/atsamd51x`: use PCHCTRL_GCLK_SERCOMX_SLOW for setting clocks on all SERCOM ports
+  - `stm32f405`: add basic UART handler
+  - `stm32f405`: add STM32F405 machine/runtime, and new board/target feather-stm32f405
+* **build**
+  - `all`: run test binaries in the correct directory
+  - `build`: Fix arch release job
+  - `ci`: run `tinygo test` for known-working packages
+  - `ci`: set git-fetch-depth to 1
+  - `docker`: fix the problem with the wasm build (#1357)
+  - `Makefile`: check whether submodules have been downloaded in some common cases
+* **docs**
+  - add ESP32, ESP8266, and Adafruit Feather STM32F405 to list of supported boards
+
+0.14.1
+---
+* **command-line**
+  - support for Go 1.15
+* **compiler**
+  - loader:  work around Windows symlink limitation
+
 0.14.0
 ---
 * **command-line**

CONTRIBUTORS

@@ -15,4 +15,4 @@ Ayke van Laethem <aykevanlaethem@gmail.com>
 Daniel Esteban <conejo@conejo.me>
 Loon, LLC.
 Ron Evans <ron@hybridgroup.com>
-Jaden Weiss <jaden@jadendw.dev>
+Nia Weiss <niaow1234@gmail.com>

Dockerfile

@@ -1,5 +1,5 @@
-# TinyGo base stage installs Go 1.14, LLVM 10 and the TinyGo compiler itself.
-FROM golang:1.14 AS tinygo-base
+# TinyGo base stage installs the most recent Go 1.15.x, LLVM 10 and the TinyGo compiler itself.
+FROM golang:1.15 AS tinygo-base
 
 RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
     echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-10 main" >> /etc/apt/sources.list && \
@@ -27,7 +27,10 @@ COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
 COPY --from=tinygo-base /tinygo/src /tinygo/src
 COPY --from=tinygo-base /tinygo/targets /tinygo/targets
 
-RUN apt-get install -y libllvm10 lld-10
+RUN cd /tinygo/ && \
+    apt-get update && \
+    apt-get install -y make clang-10 libllvm10 lld-10 && \
+    make wasi-libc
 
 # tinygo-avr stage installs the needed dependencies to compile TinyGo programs for AVR microcontrollers.
 FROM tinygo-base AS tinygo-avr

Makefile

@@ -9,25 +9,10 @@ CLANG_SRC ?= $(LLVM_PROJECTDIR)/clang
 LLD_SRC ?= $(LLVM_PROJECTDIR)/lld
 
 # Try to autodetect LLVM build tools.
-ifneq (, $(shell command -v llvm-build/bin/clang 2> /dev/null))
-    CLANG ?= $(abspath llvm-build/bin/clang)
-else
-    CLANG ?= clang-10
-endif
-ifneq (, $(shell command -v llvm-build/bin/llvm-ar 2> /dev/null))
-    LLVM_AR ?= $(abspath llvm-build/bin/llvm-ar)
-else ifneq (, $(shell command -v llvm-ar-10 2> /dev/null))
-    LLVM_AR ?= llvm-ar-10
-else
-    LLVM_AR ?= llvm-ar
-endif
-ifneq (, $(shell command -v llvm-build/bin/llvm-nm 2> /dev/null))
-    LLVM_NM ?= $(abspath llvm-build/bin/llvm-nm)
-else ifneq (, $(shell command -v llvm-nm-10 2> /dev/null))
-    LLVM_NM ?= llvm-nm-10
-else
-    LLVM_NM ?= llvm-nm
-endif
+detect = $(shell command -v $(1) 2> /dev/null && echo $(1))
+CLANG ?= $(word 1,$(abspath $(call detect,llvm-build/bin/clang))$(call detect,clang-11)$(call detect,clang-10)$(call detect,clang))
+LLVM_AR ?= $(word 1,$(abspath $(call detect,llvm-build/bin/llvm-ar))$(call detect,llvm-ar-11)$(call detect,llvm-ar-10)$(call detect,llvm-ar))
+LLVM_NM ?= $(word 1,$(abspath $(call detect,llvm-build/bin/llvm-nm))$(call detect,llvm-nm-11)$(call detect,llvm-nm-10)$(call detect,llvm-nm))
 
 # Go binary and GOROOT to select
 GO ?= go
@@ -37,7 +22,7 @@ export GOROOT = $(shell $(GO) env GOROOT)
 MD5SUM = md5sum
 
 # tinygo binary for tests
-TINYGO ?= tinygo
+TINYGO ?= $(word 1,$(call detect,tinygo)$(call detect,build/tinygo))
 
 # Use CCACHE for LLVM if possible
 ifneq (, $(shell command -v ccache 2> /dev/null))
@@ -104,7 +89,7 @@ LLD_LIBS = $(START_GROUP) -llldCOFF -llldCommon -llldCore -llldDriver -llldELF -
 ifneq ("$(wildcard $(LLVM_BUILDDIR)/bin/llvm-config*)","")
     CGO_CPPFLAGS=$(shell $(LLVM_BUILDDIR)/bin/llvm-config --cppflags) -I$(abspath $(LLVM_BUILDDIR))/tools/clang/include -I$(abspath $(CLANG_SRC))/include -I$(abspath $(LLD_SRC))/include
     CGO_CXXFLAGS=-std=c++14
-    CGO_LDFLAGS+=$(LIBCLANG_PATH) -std=c++14 -L$(abspath $(LLVM_BUILDDIR)/lib) $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS)) -lstdc++ $(CGO_LDFLAGS_EXTRA)
+    CGO_LDFLAGS+=$(LIBCLANG_PATH) -L$(abspath $(LLVM_BUILDDIR)/lib) $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS)) -lstdc++ $(CGO_LDFLAGS_EXTRA)
 endif
 
 
@@ -118,9 +103,10 @@ fmt-check:
 	@unformatted=$$(gofmt -l $(FMT_PATHS)); [ -z "$$unformatted" ] && exit 0; echo "Unformatted:"; for fn in $$unformatted; do echo "  $$fn"; done; exit 1
 
 
-gen-device: gen-device-avr gen-device-nrf gen-device-sam gen-device-sifive gen-device-stm32 gen-device-kendryte gen-device-nxp
+gen-device: gen-device-avr gen-device-esp gen-device-nrf gen-device-sam gen-device-sifive gen-device-stm32 gen-device-kendryte gen-device-nxp
 
 gen-device-avr:
+	@if [ ! -e lib/avr/README.md ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
 	$(GO) build -o ./build/gen-device-avr ./tools/gen-device-avr/
 	./build/gen-device-avr lib/avr/packs/atmega src/device/avr/
 	./build/gen-device-avr lib/avr/packs/tiny src/device/avr/
@@ -129,6 +115,10 @@ gen-device-avr:
 build/gen-device-svd: ./tools/gen-device-svd/*.go
 	$(GO) build -o $@ ./tools/gen-device-svd/
 
+gen-device-esp: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Espressif-Community -interrupts=software lib/cmsis-svd/data/Espressif-Community/ src/device/esp/
+	GO111MODULE=off $(GO) fmt ./src/device/esp
+
 gen-device-nrf: build/gen-device-svd
 	./build/gen-device-svd -source=https://github.com/NordicSemiconductor/nrfx/tree/master/mdk lib/nrfx/mdk/ src/device/nrf/
 	GO111MODULE=off $(GO) fmt ./src/device/nrf
@@ -156,13 +146,13 @@ gen-device-stm32: build/gen-device-svd
 
 # Get LLVM sources.
 $(LLVM_PROJECTDIR)/README.md:
-	git clone -b release/10.x --depth=1 https://github.com/llvm/llvm-project $(LLVM_PROJECTDIR)
+	git clone -b xtensa_release_10.0.1 --depth=1 https://github.com/tinygo-org/llvm-project $(LLVM_PROJECTDIR)
 llvm-source: $(LLVM_PROJECTDIR)/README.md
 
 # Configure LLVM.
 TINYGO_SOURCE_DIR=$(shell pwd)
 $(LLVM_BUILDDIR)/build.ninja: llvm-source
-	mkdir -p $(LLVM_BUILDDIR); cd $(LLVM_BUILDDIR); cmake -G Ninja $(TINYGO_SOURCE_DIR)/$(LLVM_PROJECTDIR)/llvm "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64;RISCV;WebAssembly" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR" -DCMAKE_BUILD_TYPE=Release -DLIBCLANG_BUILD_STATIC=ON -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DLLVM_ENABLE_LIBEDIT=OFF -DLLVM_ENABLE_Z3_SOLVER=OFF -DLLVM_ENABLE_OCAMLDOC=OFF -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TOOL_CLANG_TOOLS_EXTRA_BUILD=OFF $(LLVM_OPTION)
+	mkdir -p $(LLVM_BUILDDIR); cd $(LLVM_BUILDDIR); cmake -G Ninja $(TINYGO_SOURCE_DIR)/$(LLVM_PROJECTDIR)/llvm "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64;RISCV;WebAssembly" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR;Xtensa" -DCMAKE_BUILD_TYPE=Release -DLIBCLANG_BUILD_STATIC=ON -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DLLVM_ENABLE_LIBEDIT=OFF -DLLVM_ENABLE_Z3_SOLVER=OFF -DLLVM_ENABLE_OCAMLDOC=OFF -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TOOL_CLANG_TOOLS_EXTRA_BUILD=OFF $(LLVM_OPTION)
 
 # Build LLVM.
 $(LLVM_BUILDDIR): $(LLVM_BUILDDIR)/build.ninja
@@ -173,19 +163,35 @@ $(LLVM_BUILDDIR): $(LLVM_BUILDDIR)/build.ninja
 .PHONY: wasi-libc
 wasi-libc: lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a
 lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a:
+	@if [ ! -e lib/wasi-libc/Makefile ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
 	cd lib/wasi-libc && make -j4 WASM_CC=$(CLANG) WASM_AR=$(LLVM_AR) WASM_NM=$(LLVM_NM)
 
 
 # Build the Go compiler.
 tinygo:
 	@if [ ! -f "$(LLVM_BUILDDIR)/bin/llvm-config" ]; then echo "Fetch and build LLVM first by running:"; echo "  make llvm-source"; echo "  make $(LLVM_BUILDDIR)"; exit 1; fi
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) build -o build/tinygo$(EXE) -tags byollvm .
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) build -buildmode exe -o build/tinygo$(EXE) -tags byollvm -ldflags="-X main.gitSha1=`git rev-parse --short HEAD`" .
 
 test: wasi-libc
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -tags byollvm ./cgo ./compileopts ./interp ./transform .
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -buildmode exe -tags byollvm ./cgo ./compileopts ./interp ./transform .
 
+# Test known-working standard library packages.
+# TODO: do this in one command, parallelize, and only show failing tests (no
+# implied -v flag).
+.PHONY: tinygo-test
 tinygo-test:
-	cd tests/tinygotest && tinygo test
+	$(TINYGO) test container/heap
+	$(TINYGO) test container/list
+	$(TINYGO) test container/ring
+	$(TINYGO) test crypto/des
+	$(TINYGO) test encoding/ascii85
+	$(TINYGO) test encoding/base32
+	$(TINYGO) test encoding/hex
+	$(TINYGO) test hash/fnv
+	$(TINYGO) test hash/crc64
+	$(TINYGO) test math
+	$(TINYGO) test text/scanner
+	$(TINYGO) test unicode/utf8
 
 .PHONY: smoketest
 smoketest:
@@ -222,8 +228,6 @@ smoketest:
 	# test simulated boards on play.tinygo.org
 	$(TINYGO) build             -o test.wasm -tags=arduino              examples/blinky1
 	@$(MD5SUM) test.wasm
-	$(TINYGO) build             -o test.wasm -tags=hifive1-qemu         examples/serial
-	@$(MD5SUM) test.wasm
 	$(TINYGO) build             -o test.wasm -tags=hifive1b             examples/blinky1
 	@$(MD5SUM) test.wasm
 	$(TINYGO) build             -o test.wasm -tags=reelboard            examples/blinky1
@@ -267,13 +271,15 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=stm32f4disco        examples/blinky2
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=stm32f4disco-1       examples/blinky1
+	$(TINYGO) build -size short -o test.hex -target=stm32f4disco-1      examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-stm32f405   examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-bluefruit examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/i2s
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=clue_alpha          examples/blinky1
+	$(TINYGO) build -size short -o test.hex -target=clue-alpha          examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.gba -target=gameboy-advance     examples/gba-display
 	@$(MD5SUM) test.gba
@@ -315,6 +321,23 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-nrf52840  	examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-nrf52840  examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=qtpy  				examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=teensy40            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=teensy36            examples/blinky1
+	@$(MD5SUM) test.hex
+	# test pwm
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m4        examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/pwm
+	@$(MD5SUM) test.hex
 ifneq ($(AVR), 0)
 	$(TINYGO) build -size short -o test.hex -target=atmega1284p         examples/serial
 	@$(MD5SUM) test.hex
@@ -330,9 +353,17 @@ ifneq ($(AVR), 0)
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=digispark -gc=leaking examples/blinky1
 	@$(MD5SUM) test.hex
+endif
+ifneq ($(XTENSA), 0)
+	$(TINYGO) build -size short -o test.bin -target=esp32-mini32      	examples/blinky1
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=nodemcu             examples/blinky1
+	@$(MD5SUM) test.bin
 endif
 	$(TINYGO) build -size short -o test.hex -target=hifive1b            examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=hifive1-qemu        examples/serial
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=maixbit             examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/export
@@ -342,8 +373,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040 -opt=1     examples/blinky1
 	@$(MD5SUM) test.hex
-	$(TINYGO) build             -o test.elf -target=nintendoswitch      examples/serial
-	@$(MD5SUM) test.elf
+	$(TINYGO) build             -o test.nro -target=nintendoswitch      examples/serial
+	@$(MD5SUM) test.nro
 
 wasmtest:
 	$(GO) test ./tests/wasm

README.md

@@ -43,7 +43,7 @@ See the [getting started instructions](https://tinygo.org/getting-started/) for
 
 You can compile TinyGo programs for microcontrollers, WebAssembly and Linux.
 
-The following 39 microcontroller boards/devices are currently supported:
+The following 44 microcontroller boards are currently supported:
 
 * [Adafruit Circuit Playground Bluefruit](https://www.adafruit.com/product/4333)
 * [Adafruit Circuit Playground Express](https://www.adafruit.com/product/3333)
@@ -51,8 +51,10 @@ The following 39 microcontroller boards/devices are currently supported:
 * [Adafruit Feather M0](https://www.adafruit.com/product/2772)
 * [Adafruit Feather M4](https://www.adafruit.com/product/3857)
 * [Adafruit Feather nRF52840 Express](https://www.adafruit.com/product/4062)
+* [Adafruit Feather STM32F405 Express](https://www.adafruit.com/product/4382)
 * [Adafruit ItsyBitsy M0](https://www.adafruit.com/product/3727)
 * [Adafruit ItsyBitsy M4](https://www.adafruit.com/product/3800)
+* [Adafruit ItsyBitsy nRF52840](https://www.adafruit.com/product/4481)
 * [Adafruit Metro M4 Express Airlift](https://www.adafruit.com/product/4000)
 * [Adafruit PyBadge](https://www.adafruit.com/product/4200)
 * [Adafruit PyGamer](https://www.adafruit.com/product/4242)
@@ -62,8 +64,11 @@ The following 39 microcontroller boards/devices are currently supported:
 * [Arduino Nano](https://store.arduino.cc/arduino-nano)
 * [Arduino Nano33 IoT](https://store.arduino.cc/nano-33-iot)
 * [Arduino Uno](https://store.arduino.cc/arduino-uno-rev3)
+* [Arduino Zero](https://store.arduino.cc/usa/arduino-zero)
 * [BBC micro:bit](https://microbit.org/)
 * [Digispark](http://digistump.com/products/1)
+* [ESP32](https://www.espressif.com/en/products/socs/esp32)
+* [ESP8266](https://www.espressif.com/en/products/socs/esp8266)
 * [Game Boy Advance](https://en.wikipedia.org/wiki/Game_Boy_Advance)
 * [Makerdiary nRF52840-MDK](https://wiki.makerdiary.com/nrf52840-mdk/)
 * [Nintendo Switch](https://www.nintendo.com/switch/)

azure-pipelines.yml

@@ -12,22 +12,27 @@ jobs:
   steps:
     - task: GoTool@0
       inputs:
-        version: '1.14.1'
+        version: '1.15'
     - checkout: self
-    - task: CacheBeta@0
+      fetchDepth: 1
+    - task: Cache@2
       displayName: Cache LLVM source
       inputs:
-        key: llvm-source-10-windows-v0
+        key: llvm-source-10-windows-v1
         path: llvm-project
     - task: Bash@3
       displayName: Download LLVM source
       inputs:
         targetType: inline
-        script: make llvm-source
+        script: |
+          make llvm-source
+          # Workaround for bad symlinks:
+          # https://github.com/microsoft/azure-pipelines-tasks/issues/13418
+          rm -f llvm-project/libcxx/test/std/input.output/filesystems/Inputs/static_test_env/bad_symlink
     - task: CacheBeta@0
       displayName: Cache LLVM build
       inputs:
-        key: llvm-build-10-windows-v0
+        key: llvm-build-10-windows-v1
         path: llvm-build
     - task: Bash@3
       displayName: Build LLVM
@@ -47,7 +52,7 @@ jobs:
     - task: CacheBeta@0
       displayName: Cache wasi-libc sysroot
       inputs:
-        key: wasi-libc-sysroot-v2
+        key: wasi-libc-sysroot-v3
         path: lib/wasi-libc/sysroot
     - task: Bash@3
       displayName: Build wasi-libc
@@ -80,4 +85,4 @@ jobs:
         script: |
           export PATH="$PATH:./llvm-build/bin:/c/Program Files/qemu"
           unset GOROOT
-          make smoketest TINYGO=build/tinygo AVR=0
+          make smoketest TINYGO=build/tinygo AVR=0 XTENSA=0

builder/build.go

@@ -5,6 +5,7 @@ package builder
 
 import (
 	"debug/elf"
+	"encoding/binary"
 	"errors"
 	"fmt"
 	"io/ioutil"
@@ -23,22 +24,35 @@ import (
 	"tinygo.org/x/go-llvm"
 )
 
+// BuildResult is the output of a build. This includes the binary itself and
+// some other metadata that is obtained while building the binary.
+type BuildResult struct {
+	// A path to the output binary. It will be removed after Build returns, so
+	// if it should be kept it must be copied or moved away.
+	Binary string
+
+	// The directory of the main package. This is useful for testing as the test
+	// binary must be run in the directory of the tested package.
+	MainDir string
+}
+
 // Build performs a single package to executable Go build. It takes in a package
 // name, an output path, and set of compile options and from that it manages the
 // whole compilation process.
 //
 // The error value may be of type *MultiError. Callers will likely want to check
 // for this case and print such errors individually.
-func Build(pkgName, outpath string, config *compileopts.Config, action func(string) error) error {
+func Build(pkgName, outpath string, config *compileopts.Config, action func(BuildResult) error) error {
 	// Compile Go code to IR.
 	machine, err := compiler.NewTargetMachine(config)
 	if err != nil {
 		return err
 	}
-	mod, extraFiles, extraLDFlags, errs := compiler.Compile(pkgName, machine, config)
+	buildOutput, errs := compiler.Compile(pkgName, machine, config)
 	if errs != nil {
 		return newMultiError(errs)
 	}
+	mod := buildOutput.Mod
 
 	if config.Options.PrintIR {
 		fmt.Println("; Generated LLVM IR:")
@@ -65,7 +79,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 	// keep functions interoperable, pass int64 types as pointers to
 	// stack-allocated values.
 	// Use -wasm-abi=generic to disable this behaviour.
-	if config.Options.WasmAbi == "js" && strings.HasPrefix(config.Triple(), "wasm") {
+	if config.WasmAbi() == "js" {
 		err := transform.ExternalInt64AsPtr(mod)
 		if err != nil {
 			return err
@@ -103,16 +117,22 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 		return errors.New("verification failure after LLVM optimization passes")
 	}
 
-	// On the AVR, pointers can point either to flash or to RAM, but we don't
-	// know. As a temporary fix, load all global variables in RAM.
-	// In the future, there should be a compiler pass that determines which
-	// pointers are flash and which are in RAM so that pointers can have a
-	// correct address space parameter (address space 1 is for flash).
-	if strings.HasPrefix(config.Triple(), "avr") {
-		transform.NonConstGlobals(mod)
-		if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
-			return errors.New("verification error after making all globals non-constant on AVR")
-		}
+	// LLVM 11 by default tries to emit tail calls (even with the target feature
+	// disabled) unless it is explicitly disabled with a function attribute.
+	// This is a problem, as it tries to emit them and prints an error when it
+	// can't with this feature disabled.
+	// Because as of september 2020 tail calls are not yet widely supported,
+	// they need to be disabled until they are widely supported (at which point
+	// the +tail-call target feautre can be set).
+	if strings.HasPrefix(config.Triple(), "wasm") {
+		transform.DisableTailCalls(mod)
+	}
+
+	// Make sure stack sizes are loaded from a separate section so they can be
+	// modified after linking.
+	var stackSizeLoads []string
+	if config.AutomaticStackSize() {
+		stackSizeLoads = transform.CreateStackSizeLoads(mod, config)
 	}
 
 	// Generate output.
@@ -188,7 +208,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 		}
 
 		// Compile C files in packages.
-		for i, file := range extraFiles {
+		for i, file := range buildOutput.ExtraFiles {
 			outpath := filepath.Join(dir, "pkg"+strconv.Itoa(i)+"-"+filepath.Base(file)+".o")
 			err := runCCompiler(config.Target.Compiler, append(config.CFlags(), "-c", "-o", outpath, file)...)
 			if err != nil {
@@ -197,8 +217,8 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 			ldflags = append(ldflags, outpath)
 		}
 
-		if len(extraLDFlags) > 0 {
-			ldflags = append(ldflags, extraLDFlags...)
+		if len(buildOutput.ExtraLDFlags) > 0 {
+			ldflags = append(ldflags, buildOutput.ExtraLDFlags...)
 		}
 
 		// Link the object files together.
@@ -207,6 +227,26 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 			return &commandError{"failed to link", executable, err}
 		}
 
+		var calculatedStacks []string
+		var stackSizes map[string]functionStackSize
+		if config.Options.PrintStacks || config.AutomaticStackSize() {
+			// Try to determine stack sizes at compile time.
+			// Don't do this by default as it usually doesn't work on
+			// unsupported architectures.
+			calculatedStacks, stackSizes, err = determineStackSizes(mod, executable)
+			if err != nil {
+				return err
+			}
+		}
+		if config.AutomaticStackSize() {
+			// Modify the .tinygo_stacksizes section that contains a stack size
+			// for each goroutine.
+			err = modifyStackSizes(executable, stackSizeLoads, stackSizes)
+			if err != nil {
+				return fmt.Errorf("could not modify stack sizes: %w", err)
+			}
+		}
+
 		if config.Options.PrintSizes == "short" || config.Options.PrintSizes == "full" {
 			sizes, err := loadProgramSize(executable)
 			if err != nil {
@@ -228,28 +268,250 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 
 		// Print goroutine stack sizes, as far as possible.
 		if config.Options.PrintStacks {
-			printStacks(mod, executable)
+			printStacks(calculatedStacks, stackSizes)
 		}
 
 		// Get an Intel .hex file or .bin file from the .elf file.
-		if outext == ".hex" || outext == ".bin" || outext == ".gba" {
+		outputBinaryFormat := config.BinaryFormat(outext)
+		switch outputBinaryFormat {
+		case "elf":
+			// do nothing, file is already in ELF format
+		case "hex", "bin":
+			// Extract raw binary, either encoding it as a hex file or as a raw
+			// firmware file.
 			tmppath = filepath.Join(dir, "main"+outext)
-			err := objcopy(executable, tmppath)
+			err := objcopy(executable, tmppath, outputBinaryFormat)
 			if err != nil {
 				return err
 			}
-		} else if outext == ".uf2" {
+		case "uf2":
 			// Get UF2 from the .elf file.
 			tmppath = filepath.Join(dir, "main"+outext)
 			err := convertELFFileToUF2File(executable, tmppath, config.Target.UF2FamilyID)
 			if err != nil {
 				return err
 			}
+		case "esp32", "esp8266":
+			// Special format for the ESP family of chips (parsed by the ROM
+			// bootloader).
+			tmppath = filepath.Join(dir, "main"+outext)
+			err := makeESPFirmareImage(executable, tmppath, outputBinaryFormat)
+			if err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("unknown output binary format: %s", outputBinaryFormat)
 		}
-		return action(tmppath)
+		return action(BuildResult{
+			Binary:  tmppath,
+			MainDir: buildOutput.MainDir,
+		})
 	}
 }
 
+// functionStackSizes keeps stack size information about a single function
+// (usually a goroutine).
+type functionStackSize struct {
+	humanName        string
+	stackSize        uint64
+	stackSizeType    stacksize.SizeType
+	missingStackSize *stacksize.CallNode
+}
+
+// determineStackSizes tries to determine the stack sizes of all started
+// goroutines and of the reset vector. The LLVM module is necessary to find
+// functions that call a function pointer.
+func determineStackSizes(mod llvm.Module, executable string) ([]string, map[string]functionStackSize, error) {
+	var callsIndirectFunction []string
+	gowrappers := []string{}
+	gowrapperNames := make(map[string]string)
+	for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+		// Determine which functions call a function pointer.
+		for bb := fn.FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
+			for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+				if inst.IsACallInst().IsNil() {
+					continue
+				}
+				if callee := inst.CalledValue(); callee.IsAFunction().IsNil() && callee.IsAInlineAsm().IsNil() {
+					callsIndirectFunction = append(callsIndirectFunction, fn.Name())
+				}
+			}
+		}
+
+		// Get a list of "go wrappers", small wrapper functions that decode
+		// parameters when starting a new goroutine.
+		attr := fn.GetStringAttributeAtIndex(-1, "tinygo-gowrapper")
+		if !attr.IsNil() {
+			gowrappers = append(gowrappers, fn.Name())
+			gowrapperNames[fn.Name()] = attr.GetStringValue()
+		}
+	}
+	sort.Strings(gowrappers)
+
+	// Load the ELF binary.
+	f, err := elf.Open(executable)
+	if err != nil {
+		return nil, nil, fmt.Errorf("could not load executable for stack size analysis: %w", err)
+	}
+	defer f.Close()
+
+	// Determine the frame size of each function (if available) and the callgraph.
+	functions, err := stacksize.CallGraph(f, callsIndirectFunction)
+	if err != nil {
+		return nil, nil, fmt.Errorf("could not parse executable for stack size analysis: %w", err)
+	}
+
+	// Goroutines need to be started and finished and take up some stack space
+	// that way. This can be measured by measuing the stack size of
+	// tinygo_startTask.
+	if numFuncs := len(functions["tinygo_startTask"]); numFuncs != 1 {
+		return nil, nil, fmt.Errorf("expected exactly one definition of tinygo_startTask, got %d", numFuncs)
+	}
+	baseStackSize, baseStackSizeType, baseStackSizeFailedAt := functions["tinygo_startTask"][0].StackSize()
+
+	sizes := make(map[string]functionStackSize)
+
+	// Add the reset handler function, for convenience. The reset handler runs
+	// startup code and the scheduler. The listed stack size is not the full
+	// stack size: interrupts are not counted.
+	var resetFunction string
+	switch f.Machine {
+	case elf.EM_ARM:
+		// Note: all interrupts happen on this stack so the real size is bigger.
+		resetFunction = "Reset_Handler"
+	}
+	if resetFunction != "" {
+		funcs := functions[resetFunction]
+		if len(funcs) != 1 {
+			return nil, nil, fmt.Errorf("expected exactly one definition of %s in the callgraph, found %d", resetFunction, len(funcs))
+		}
+		stackSize, stackSizeType, missingStackSize := funcs[0].StackSize()
+		sizes[resetFunction] = functionStackSize{
+			stackSize:        stackSize,
+			stackSizeType:    stackSizeType,
+			missingStackSize: missingStackSize,
+			humanName:        resetFunction,
+		}
+	}
+
+	// Add all goroutine wrapper functions.
+	for _, name := range gowrappers {
+		funcs := functions[name]
+		if len(funcs) != 1 {
+			return nil, nil, fmt.Errorf("expected exactly one definition of %s in the callgraph, found %d", name, len(funcs))
+		}
+		humanName := gowrapperNames[name]
+		if humanName == "" {
+			humanName = name // fallback
+		}
+		stackSize, stackSizeType, missingStackSize := funcs[0].StackSize()
+		if baseStackSizeType != stacksize.Bounded {
+			// It was not possible to determine the stack size at compile time
+			// because tinygo_startTask does not have a fixed stack size. This
+			// can happen when using -opt=1.
+			stackSizeType = baseStackSizeType
+			missingStackSize = baseStackSizeFailedAt
+		} else if stackSize < baseStackSize {
+			// This goroutine has a very small stack, but still needs to fit all
+			// registers to start and suspend the goroutine. Otherwise a stack
+			// overflow will occur even before the goroutine is started.
+			stackSize = baseStackSize
+		}
+		sizes[name] = functionStackSize{
+			stackSize:        stackSize,
+			stackSizeType:    stackSizeType,
+			missingStackSize: missingStackSize,
+			humanName:        humanName,
+		}
+	}
+
+	if resetFunction != "" {
+		return append([]string{resetFunction}, gowrappers...), sizes, nil
+	}
+	return gowrappers, sizes, nil
+}
+
+// modifyStackSizes modifies the .tinygo_stacksizes section with the updated
+// stack size information. Before this modification, all stack sizes in the
+// section assume the default stack size (which is relatively big).
+func modifyStackSizes(executable string, stackSizeLoads []string, stackSizes map[string]functionStackSize) error {
+	fp, err := os.OpenFile(executable, os.O_RDWR, 0)
+	if err != nil {
+		return err
+	}
+	defer fp.Close()
+
+	elfFile, err := elf.NewFile(fp)
+	if err != nil {
+		return err
+	}
+
+	section := elfFile.Section(".tinygo_stacksizes")
+	if section == nil {
+		return errors.New("could not find .tinygo_stacksizes section")
+	}
+
+	if section.Size != section.FileSize {
+		// Sanity check.
+		return fmt.Errorf("expected .tinygo_stacksizes to have identical size and file size, got %d and %d", section.Size, section.FileSize)
+	}
+
+	// Read all goroutine stack sizes.
+	data := make([]byte, section.Size)
+	_, err = fp.ReadAt(data, int64(section.Offset))
+	if err != nil {
+		return err
+	}
+
+	if len(stackSizeLoads)*4 != len(data) {
+		// Note: while AVR should use 2 byte stack sizes, even 64-bit platforms
+		// should probably stick to 4 byte stack sizes as a larger than 4GB
+		// stack doesn't make much sense.
+		return errors.New("expected 4 byte stack sizes")
+	}
+
+	// Modify goroutine stack sizes with a compile-time known worst case stack
+	// size.
+	for i, name := range stackSizeLoads {
+		fn, ok := stackSizes[name]
+		if !ok {
+			return fmt.Errorf("could not find symbol %s in ELF file", name)
+		}
+		if fn.stackSizeType == stacksize.Bounded {
+			stackSize := uint32(fn.stackSize)
+
+			// Adding 4 for the stack canary. Even though the size may be
+			// automatically determined, stack overflow checking is still
+			// important as the stack size cannot be determined for all
+			// goroutines.
+			stackSize += 4
+
+			// Add stack size used by interrupts.
+			switch elfFile.Machine {
+			case elf.EM_ARM:
+				// On Cortex-M (assumed here), this stack size is 8 words or 32
+				// bytes. This is only to store the registers that the interrupt
+				// may modify, the interrupt will switch to the interrupt stack
+				// (MSP).
+				// Some background:
+				// https://interrupt.memfault.com/blog/cortex-m-rtos-context-switching
+				stackSize += 32
+			}
+
+			// Finally write the stack size to the binary.
+			binary.LittleEndian.PutUint32(data[i*4:], stackSize)
+		}
+	}
+
+	// Write back the modified stack sizes.
+	_, err = fp.WriteAt(data, int64(section.Offset))
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // printStacks prints the maximum stack depth for functions that are started as
 // goroutines. Stack sizes cannot always be determined statically, in particular
 // recursive functions and functions that call interface methods or function
@@ -260,78 +522,22 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 //
 //     function                         stack usage (in bytes)
 //     Reset_Handler                    316
-//     .Lexamples/blinky2.led1          92
-//     .Lruntime.run$1                  300
-func printStacks(mod llvm.Module, executable string) {
-	// Determine which functions call a function pointer.
-	var callsIndirectFunction []string
-	for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
-		for bb := fn.FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
-			for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
-				if inst.IsACallInst().IsNil() {
-					continue
-				}
-				if callee := inst.CalledValue(); callee.IsAFunction().IsNil() && callee.IsAInlineAsm().IsNil() {
-					callsIndirectFunction = append(callsIndirectFunction, fn.Name())
-				}
-			}
-		}
-	}
-
-	// Load the ELF binary.
-	f, err := elf.Open(executable)
-	if err != nil {
-		fmt.Fprintln(os.Stderr, "could not load executable for stack size analysis:", err)
-		return
-	}
-	defer f.Close()
-
-	// Determine the frame size of each function (if available) and the callgraph.
-	functions, err := stacksize.CallGraph(f, callsIndirectFunction)
-	if err != nil {
-		fmt.Fprintln(os.Stderr, "could not parse executable for stack size analysis:", err)
-		return
-	}
-
-	// Get a list of "go wrappers", small wrapper functions that decode
-	// parameters when starting a new goroutine.
-	var gowrappers []string
-	for name := range functions {
-		if strings.HasSuffix(name, "$gowrapper") {
-			gowrappers = append(gowrappers, name)
-		}
-	}
-	sort.Strings(gowrappers)
-
-	switch f.Machine {
-	case elf.EM_ARM:
-		// Add the reset handler, which runs startup code and is the
-		// interrupt/scheduler stack with -scheduler=tasks.
-		// Note that because interrupts happen on this stack, the stack needed
-		// by just the Reset_Handler is not enough. Stacks needed by interrupt
-		// handlers should also be taken into account.
-		gowrappers = append([]string{"Reset_Handler"}, gowrappers...)
-	}
-
+//     examples/blinky2.led1            92
+//     runtime.run$1                    300
+func printStacks(calculatedStacks []string, stackSizes map[string]functionStackSize) {
 	// Print the sizes of all stacks.
 	fmt.Printf("%-32s %s\n", "function", "stack usage (in bytes)")
-	for _, name := range gowrappers {
-		for _, fn := range functions[name] {
-			stackSize, stackSizeType, missingStackSize := fn.StackSize()
-			strippedName := name
-			if strings.HasSuffix(name, "$gowrapper") {
-				strippedName = name[:len(name)-len("$gowrapper")]
-			}
-			switch stackSizeType {
-			case stacksize.Bounded:
-				fmt.Printf("%-32s %d\n", strippedName, stackSize)
-			case stacksize.Unknown:
-				fmt.Printf("%-32s unknown, %s does not have stack frame information\n", strippedName, missingStackSize)
-			case stacksize.Recursive:
-				fmt.Printf("%-32s recursive, %s may call itself\n", strippedName, missingStackSize)
-			case stacksize.IndirectCall:
-				fmt.Printf("%-32s unknown, %s calls a function pointer\n", strippedName, missingStackSize)
-			}
+	for _, name := range calculatedStacks {
+		fn := stackSizes[name]
+		switch fn.stackSizeType {
+		case stacksize.Bounded:
+			fmt.Printf("%-32s %d\n", fn.humanName, fn.stackSize)
+		case stacksize.Unknown:
+			fmt.Printf("%-32s unknown, %s does not have stack frame information\n", fn.humanName, fn.missingStackSize)
+		case stacksize.Recursive:
+			fmt.Printf("%-32s recursive, %s may call itself\n", fn.humanName, fn.missingStackSize)
+		case stacksize.IndirectCall:
+			fmt.Printf("%-32s unknown, %s calls a function pointer\n", fn.humanName, fn.missingStackSize)
 		}
 	}
 }

builder/config.go

@@ -25,8 +25,8 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 	if err != nil {
 		return nil, fmt.Errorf("could not read version from GOROOT (%v): %v", goroot, err)
 	}
-	if major != 1 || minor < 11 || minor > 14 {
-		return nil, fmt.Errorf("requires go version 1.11, 1.12, 1.13, or 1.14, got go%d.%d", major, minor)
+	if major != 1 || minor < 11 || minor > 15 {
+		return nil, fmt.Errorf("requires go version 1.11 through 1.15, got go%d.%d", major, minor)
 	}
 	clangHeaderPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
 	return &compileopts.Config{

builder/env.go

@@ -6,6 +6,9 @@ import (
 	"os/exec"
 	"path/filepath"
 	"sort"
+	"strings"
+
+	"tinygo.org/x/go-llvm"
 )
 
 // getClangHeaderPath returns the path to the built-in Clang headers. It tries
@@ -26,6 +29,7 @@ func getClangHeaderPath(TINYGOROOT string) string {
 
 	// It looks like we are built with a system-installed LLVM. Do a last
 	// attempt: try to use Clang headers relative to the clang binary.
+	llvmMajor := strings.Split(llvm.Version, ".")[0]
 	for _, cmdName := range commands["clang"] {
 		binpath, err := exec.LookPath(cmdName)
 		if err == nil {
@@ -40,22 +44,38 @@ func getClangHeaderPath(TINYGOROOT string) string {
 			// Example executable:
 			//     /usr/lib/llvm-9/bin/clang
 			// Example include path:
-			//     /usr/lib/llvm-9/lib/clang/9.0.1/include/
+			//     /usr/lib/llvm-9/lib64/clang/9.0.1/include/
 			llvmRoot := filepath.Dir(filepath.Dir(binpath))
-			clangVersionRoot := filepath.Join(llvmRoot, "lib", "clang")
-			dirs, err := ioutil.ReadDir(clangVersionRoot)
-			if err != nil {
+			clangVersionRoot := filepath.Join(llvmRoot, "lib64", "clang")
+			dirs64, err64 := ioutil.ReadDir(clangVersionRoot)
+			// Example include path:
+			//     /usr/lib/llvm-9/lib/clang/9.0.1/include/
+			clangVersionRoot = filepath.Join(llvmRoot, "lib", "clang")
+			dirs32, err32 := ioutil.ReadDir(clangVersionRoot)
+			if err64 != nil && err32 != nil {
 				// Unexpected.
 				continue
 			}
-			dirnames := make([]string, len(dirs))
-			for i, d := range dirs {
-				dirnames[i] = d.Name()
+			dirnames := make([]string, len(dirs64)+len(dirs32))
+			dirCount := 0
+			for _, d := range dirs32 {
+				name := d.Name()
+				if name == llvmMajor || strings.HasPrefix(name, llvmMajor+".") {
+					dirnames[dirCount] = filepath.Join(llvmRoot, "lib", "clang", name)
+					dirCount++
+				}
+			}
+			for _, d := range dirs64 {
+				name := d.Name()
+				if name == llvmMajor || strings.HasPrefix(name, llvmMajor+".") {
+					dirnames[dirCount] = filepath.Join(llvmRoot, "lib64", "clang", name)
+					dirCount++
+				}
 			}
 			sort.Strings(dirnames)
 			// Check for the highest version first.
-			for i := len(dirnames) - 1; i >= 0; i-- {
-				path := filepath.Join(clangVersionRoot, dirnames[i], "include")
+			for i := dirCount - 1; i >= 0; i-- {
+				path := filepath.Join(dirnames[i], "include")
 				_, err := os.Stat(filepath.Join(path, "stdint.h"))
 				if err == nil {
 					return path

builder/esp.go

@@ -0,0 +1,153 @@
+package builder
+
+// This file implements support for writing ESP image files. These image files
+// are read by the ROM bootloader so have to be in a particular format.
+//
+// In the future, it may be necessary to implement support for other image
+// formats, such as the ESP8266 image formats (again, used by the ROM bootloader
+// to load the firmware).
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"debug/elf"
+	"encoding/binary"
+	"fmt"
+	"io/ioutil"
+	"sort"
+)
+
+type espImageSegment struct {
+	addr uint32
+	data []byte
+}
+
+// makeESPFirmare converts an input ELF file to an image file for an ESP32 or
+// ESP8266 chip. This is a special purpose image format just for the ESP chip
+// family, and is parsed by the on-chip mask ROM bootloader.
+//
+// The following documentation has been used:
+// https://github.com/espressif/esptool/wiki/Firmware-Image-Format
+// https://github.com/espressif/esp-idf/blob/8fbb63c2a701c22ccf4ce249f43aded73e134a34/components/bootloader_support/include/esp_image_format.h#L58
+// https://github.com/espressif/esptool/blob/master/esptool.py
+func makeESPFirmareImage(infile, outfile, format string) error {
+	inf, err := elf.Open(infile)
+	if err != nil {
+		return err
+	}
+	defer inf.Close()
+
+	// Load all segments to be written to the image. These are actually ELF
+	// sections, not true ELF segments (similar to how esptool does it).
+	var segments []*espImageSegment
+	for _, section := range inf.Sections {
+		if section.Type != elf.SHT_PROGBITS || section.Size == 0 || section.Flags&elf.SHF_ALLOC == 0 {
+			continue
+		}
+		data, err := section.Data()
+		if err != nil {
+			return fmt.Errorf("failed to read section data: %w", err)
+		}
+		for len(data)%4 != 0 {
+			// Align segment to 4 bytes.
+			data = append(data, 0)
+		}
+		if uint64(uint32(section.Addr)) != section.Addr {
+			return fmt.Errorf("section address too big: 0x%x", section.Addr)
+		}
+		segments = append(segments, &espImageSegment{
+			addr: uint32(section.Addr),
+			data: data,
+		})
+	}
+
+	// Sort the segments by address. This is what esptool does too.
+	sort.SliceStable(segments, func(i, j int) bool { return segments[i].addr < segments[j].addr })
+
+	// Calculate checksum over the segment data. This is used in the image
+	// footer.
+	checksum := uint8(0xef)
+	for _, segment := range segments {
+		for _, b := range segment.data {
+			checksum ^= b
+		}
+	}
+
+	// Write first to an in-memory buffer, primarily so that we can easily
+	// calculate a hash over the entire image.
+	// An added benefit is that we don't need to check for errors all the time.
+	outf := &bytes.Buffer{}
+
+	// Image header.
+	switch format {
+	case "esp32":
+		// Header format:
+		// https://github.com/espressif/esp-idf/blob/8fbb63c2/components/bootloader_support/include/esp_image_format.h#L58
+		binary.Write(outf, binary.LittleEndian, struct {
+			magic          uint8
+			segment_count  uint8
+			spi_mode       uint8
+			spi_speed_size uint8
+			entry_addr     uint32
+			wp_pin         uint8
+			spi_pin_drv    [3]uint8
+			reserved       [11]uint8
+			hash_appended  bool
+		}{
+			magic:          0xE9,
+			segment_count:  byte(len(segments)),
+			spi_mode:       0, // irrelevant, replaced by esptool when flashing
+			spi_speed_size: 0, // spi_speed, spi_size: replaced by esptool when flashing
+			entry_addr:     uint32(inf.Entry),
+			wp_pin:         0xEE, // disable WP pin
+			hash_appended:  true, // add a SHA256 hash
+		})
+	case "esp8266":
+		// Header format:
+		// https://github.com/espressif/esptool/wiki/Firmware-Image-Format
+		// Basically a truncated version of the ESP32 header.
+		binary.Write(outf, binary.LittleEndian, struct {
+			magic          uint8
+			segment_count  uint8
+			spi_mode       uint8
+			spi_speed_size uint8
+			entry_addr     uint32
+		}{
+			magic:          0xE9,
+			segment_count:  byte(len(segments)),
+			spi_mode:       0,    // irrelevant, replaced by esptool when flashing
+			spi_speed_size: 0x20, // spi_speed, spi_size: replaced by esptool when flashing
+			entry_addr:     uint32(inf.Entry),
+		})
+	default:
+		return fmt.Errorf("builder: unknown binary format %#v, expected esp32 or esp8266", format)
+	}
+
+	// Write all segments to the image.
+	// https://github.com/espressif/esptool/wiki/Firmware-Image-Format#segment
+	for _, segment := range segments {
+		binary.Write(outf, binary.LittleEndian, struct {
+			addr   uint32
+			length uint32
+		}{
+			addr:   segment.addr,
+			length: uint32(len(segment.data)),
+		})
+		outf.Write(segment.data)
+	}
+
+	// Footer, including checksum.
+	// The entire image size must be a multiple of 16, so pad the image to one
+	// byte less than that before writing the checksum.
+	outf.Write(make([]byte, 15-outf.Len()%16))
+	outf.WriteByte(checksum)
+
+	if format == "esp32" {
+		// SHA256 hash (to protect against image corruption, not for security).
+		hash := sha256.Sum256(outf.Bytes())
+		outf.Write(hash[:])
+	}
+
+	// Write the image to the output file.
+	return ioutil.WriteFile(outfile, outf.Bytes(), 0666)
+}

builder/objcopy.go

@@ -4,12 +4,15 @@ import (
 	"debug/elf"
 	"io/ioutil"
 	"os"
-	"path/filepath"
 	"sort"
 
 	"github.com/marcinbor85/gohex"
 )
 
+// maxPadBytes is the maximum allowed bytes to be padded in a rom extraction
+// this value is currently defined by Nintendo Switch Page Alignment (4096 bytes)
+const maxPadBytes = 4095
+
 // objcopyError is an error returned by functions that act like objcopy.
 type objcopyError struct {
 	Op  string
@@ -58,7 +61,7 @@ func extractROM(path string) (uint64, []byte, error) {
 
 	progs := make(progSlice, 0, 2)
 	for _, prog := range f.Progs {
-		if prog.Type != elf.PT_LOAD || prog.Filesz == 0 {
+		if prog.Type != elf.PT_LOAD || prog.Filesz == 0 || prog.Off == 0 {
 			continue
 		}
 		progs = append(progs, prog)
@@ -70,8 +73,19 @@ func extractROM(path string) (uint64, []byte, error) {
 
 	var rom []byte
 	for _, prog := range progs {
+		romEnd := progs[0].Paddr + uint64(len(rom))
+		if prog.Paddr > romEnd && prog.Paddr < romEnd+16 {
+			// Sometimes, the linker seems to insert a bit of padding between
+			// segments. Simply zero-fill these parts.
+			rom = append(rom, make([]byte, prog.Paddr-romEnd)...)
+		}
 		if prog.Paddr != progs[0].Paddr+uint64(len(rom)) {
-			return 0, nil, objcopyError{"ROM segments are non-contiguous: " + path, nil}
+			diff := prog.Paddr - (progs[0].Paddr + uint64(len(rom)))
+			if diff > maxPadBytes {
+				return 0, nil, objcopyError{"ROM segments are non-contiguous: " + path, nil}
+			}
+			// Pad the difference
+			rom = append(rom, make([]byte, diff)...)
 		}
 		data, err := ioutil.ReadAll(prog.Open())
 		if err != nil {
@@ -93,7 +107,7 @@ func extractROM(path string) (uint64, []byte, error) {
 
 // objcopy converts an ELF file to a different (simpler) output file format:
 // .bin or .hex. It extracts only the .text section.
-func objcopy(infile, outfile string) error {
+func objcopy(infile, outfile, binaryFormat string) error {
 	f, err := os.OpenFile(outfile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
 	if err != nil {
 		return err
@@ -107,23 +121,20 @@ func objcopy(infile, outfile string) error {
 	}
 
 	// Write to the file, in the correct format.
-	switch filepath.Ext(outfile) {
-	case ".gba":
-		// The address is not stored in a .gba file.
-		_, err := f.Write(data)
-		return err
-	case ".bin":
-		// The address is not stored in a .bin file (therefore you
-		// should use .hex files in most cases).
-		_, err := f.Write(data)
-		return err
-	case ".hex":
+	switch binaryFormat {
+	case "hex":
+		// Intel hex file, includes the firmware start address.
 		mem := gohex.NewMemory()
 		err := mem.AddBinary(uint32(addr), data)
 		if err != nil {
 			return objcopyError{"failed to create .hex file", err}
 		}
 		return mem.DumpIntelHex(f, 16)
+	case "bin":
+		// The start address is not stored in raw firmware files (therefore you
+		// should use .hex files in most cases).
+		_, err := f.Write(data)
+		return err
 	default:
 		panic("unreachable")
 	}

cgo/libclang_config.go

@@ -1,5 +1,5 @@
 // +build !byollvm
-// +build !llvm9
+// +build !llvm9,!llvm11
 
 package cgo
 

cgo/libclang_config_llvm11.go

@@ -0,0 +1,14 @@
+// +build !byollvm
+// +build llvm11
+
+package cgo
+
+/*
+#cgo linux   CFLAGS:  -I/usr/lib/llvm-11/include
+#cgo darwin  CFLAGS:  -I/usr/local/opt/llvm@11/include
+#cgo freebsd CFLAGS:  -I/usr/local/llvm11/include
+#cgo linux   LDFLAGS: -L/usr/lib/llvm-11/lib -lclang
+#cgo darwin  LDFLAGS: -L/usr/local/opt/llvm@11/lib -lclang -lffi
+#cgo freebsd LDFLAGS: -L/usr/local/llvm11/lib -lclang
+*/
+import "C"

compileopts/config.go

@@ -118,12 +118,12 @@ func (c *Config) NeedsStackObjects() bool {
 	switch c.GC() {
 	case "conservative", "extalloc":
 		for _, tag := range c.BuildTags() {
-			if tag == "baremetal" {
-				return false
+			if tag == "wasm" {
+				return true
 			}
 		}
 
-		return true
+		return false
 	default:
 		return false
 	}
@@ -164,6 +164,16 @@ func (c *Config) PanicStrategy() string {
 	return c.Options.PanicStrategy
 }
 
+// AutomaticStackSize returns whether goroutine stack sizes should be determined
+// automatically at compile time, if possible. If it is false, no attempt is
+// made.
+func (c *Config) AutomaticStackSize() bool {
+	if c.Target.AutoStackSize != nil && c.Scheduler() == "tasks" {
+		return *c.Target.AutoStackSize
+	}
+	return false
+}
+
 // CFlags returns the flags to pass to the C compiler. This is necessary for CGo
 // preprocessing.
 func (c *Config) CFlags() []string {
@@ -229,6 +239,31 @@ func (c *Config) Debug() bool {
 	return c.Options.Debug
 }
 
+// BinaryFormat returns an appropriate binary format, based on the file
+// extension and the configured binary format in the target JSON file.
+func (c *Config) BinaryFormat(ext string) string {
+	switch ext {
+	case ".bin", ".gba", ".nro":
+		// The simplest format possible: dump everything in a raw binary file.
+		if c.Target.BinaryFormat != "" {
+			return c.Target.BinaryFormat
+		}
+		return "bin"
+	case ".hex":
+		// Similar to bin, but includes the start address and is thus usually a
+		// better format.
+		return "hex"
+	case ".uf2":
+		// Special purpose firmware format, mainly used on Adafruit boards.
+		// More information:
+		// https://github.com/Microsoft/uf2
+		return "uf2"
+	default:
+		// Use the ELF format for unrecognized file formats.
+		return "elf"
+	}
+}
+
 // Programmer returns the flash method and OpenOCD interface name given a
 // particular configuration. It may either be all configured in the target JSON
 // file or be modified using the -programmmer command-line option.
@@ -294,6 +329,15 @@ func (c *Config) RelocationModel() string {
 	return "static"
 }
 
+// WasmAbi returns the WASM ABI which is specified in the target JSON file, and
+// the value is overridden by `-wasm-abi` flag if it is provided
+func (c *Config) WasmAbi() string {
+	if c.Options.WasmAbi != "" {
+		return c.Options.WasmAbi
+	}
+	return c.Target.WasmAbi
+}
+
 type TestConfig struct {
 	CompileTestBinary bool
 	// TODO: Filter the test functions to run, include verbose flag, etc

compileopts/target.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"reflect"
 	"runtime"
 	"strings"
 
@@ -33,11 +34,13 @@ type TargetSpec struct {
 	Linker           string   `json:"linker"`
 	RTLib            string   `json:"rtlib"` // compiler runtime library (libgcc, compiler-rt)
 	Libc             string   `json:"libc"`
+	AutoStackSize    *bool    `json:"automatic-stack-size"` // Determine stack size automatically at compile time.
+	DefaultStackSize uint64   `json:"default-stack-size"`   // Default stack size if the size couldn't be determined at compile time.
 	CFlags           []string `json:"cflags"`
 	LDFlags          []string `json:"ldflags"`
 	LinkerScript     string   `json:"linkerscript"`
 	ExtraFiles       []string `json:"extra-files"`
-	Emulator         []string `json:"emulator"`
+	Emulator         []string `json:"emulator" override:"copy"` // inherited Emulator must not be append
 	FlashCommand     string   `json:"flash-command"`
 	GDB              string   `json:"gdb"`
 	PortReset        string   `json:"flash-1200-bps-reset"`
@@ -45,99 +48,56 @@ type TargetSpec struct {
 	FlashVolume      string   `json:"msd-volume-name"`
 	FlashFilename    string   `json:"msd-firmware-name"`
 	UF2FamilyID      string   `json:"uf2-family-id"`
+	BinaryFormat     string   `json:"binary-format"`
 	OpenOCDInterface string   `json:"openocd-interface"`
 	OpenOCDTarget    string   `json:"openocd-target"`
 	OpenOCDTransport string   `json:"openocd-transport"`
 	JLinkDevice      string   `json:"jlink-device"`
 	CodeModel        string   `json:"code-model"`
 	RelocationModel  string   `json:"relocation-model"`
+	WasmAbi          string   `json:"wasm-abi"`
 }
 
-// copyProperties copies all properties that are set in spec2 into itself.
-func (spec *TargetSpec) copyProperties(spec2 *TargetSpec) {
-	// TODO: simplify this using reflection? Inherits and BuildTags are special
-	// cases, but the rest can simply be copied if set.
-	spec.Inherits = append(spec.Inherits, spec2.Inherits...)
-	if spec2.Triple != "" {
-		spec.Triple = spec2.Triple
-	}
-	if spec2.CPU != "" {
-		spec.CPU = spec2.CPU
-	}
-	spec.Features = append(spec.Features, spec2.Features...)
-	if spec2.GOOS != "" {
-		spec.GOOS = spec2.GOOS
-	}
-	if spec2.GOARCH != "" {
-		spec.GOARCH = spec2.GOARCH
-	}
-	spec.BuildTags = append(spec.BuildTags, spec2.BuildTags...)
-	if spec2.GC != "" {
-		spec.GC = spec2.GC
-	}
-	if spec2.Scheduler != "" {
-		spec.Scheduler = spec2.Scheduler
-	}
-	if spec2.Compiler != "" {
-		spec.Compiler = spec2.Compiler
-	}
-	if spec2.Linker != "" {
-		spec.Linker = spec2.Linker
-	}
-	if spec2.RTLib != "" {
-		spec.RTLib = spec2.RTLib
-	}
-	if spec2.Libc != "" {
-		spec.Libc = spec2.Libc
-	}
-	spec.CFlags = append(spec.CFlags, spec2.CFlags...)
-	spec.LDFlags = append(spec.LDFlags, spec2.LDFlags...)
-	if spec2.LinkerScript != "" {
-		spec.LinkerScript = spec2.LinkerScript
-	}
-	spec.ExtraFiles = append(spec.ExtraFiles, spec2.ExtraFiles...)
-	if len(spec2.Emulator) != 0 {
-		spec.Emulator = spec2.Emulator
-	}
-	if spec2.FlashCommand != "" {
-		spec.FlashCommand = spec2.FlashCommand
-	}
-	if spec2.GDB != "" {
-		spec.GDB = spec2.GDB
-	}
-	if spec2.PortReset != "" {
-		spec.PortReset = spec2.PortReset
-	}
-	if spec2.FlashMethod != "" {
-		spec.FlashMethod = spec2.FlashMethod
-	}
-	if spec2.FlashVolume != "" {
-		spec.FlashVolume = spec2.FlashVolume
-	}
-	if spec2.FlashFilename != "" {
-		spec.FlashFilename = spec2.FlashFilename
-	}
-	if spec2.UF2FamilyID != "" {
-		spec.UF2FamilyID = spec2.UF2FamilyID
-	}
-	if spec2.OpenOCDInterface != "" {
-		spec.OpenOCDInterface = spec2.OpenOCDInterface
-	}
-	if spec2.OpenOCDTarget != "" {
-		spec.OpenOCDTarget = spec2.OpenOCDTarget
-	}
-	if spec2.OpenOCDTransport != "" {
-		spec.OpenOCDTransport = spec2.OpenOCDTransport
-	}
-	if spec2.JLinkDevice != "" {
-		spec.JLinkDevice = spec2.JLinkDevice
-	}
-	if spec2.CodeModel != "" {
-		spec.CodeModel = spec2.CodeModel
-	}
+// overrideProperties overrides all properties that are set in child into itself using reflection.
+func (spec *TargetSpec) overrideProperties(child *TargetSpec) {
+	specType := reflect.TypeOf(spec).Elem()
+	specValue := reflect.ValueOf(spec).Elem()
+	childValue := reflect.ValueOf(child).Elem()
 
-	if spec2.RelocationModel != "" {
-		spec.RelocationModel = spec2.RelocationModel
+	for i := 0; i < specType.NumField(); i++ {
+		field := specType.Field(i)
+		src := childValue.Field(i)
+		dst := specValue.Field(i)
+
+		switch kind := field.Type.Kind(); kind {
+		case reflect.String: // for strings, just copy the field of child to spec if not empty
+			if src.Len() > 0 {
+				dst.Set(src)
+			}
+		case reflect.Uint, reflect.Uint32, reflect.Uint64: // for Uint, copy if not zero
+			if src.Uint() != 0 {
+				dst.Set(src)
+			}
+		case reflect.Ptr: // for pointers, copy if not nil
+			if !src.IsNil() {
+				dst.Set(src)
+			}
+		case reflect.Slice: // for slices...
+			if src.Len() > 0 { // ... if not empty ...
+				switch tag := field.Tag.Get("override"); tag {
+				case "copy":
+					// copy the field of child to spec
+					dst.Set(src)
+				case "append", "":
+					// or append the field of child to spec
+					dst.Set(reflect.AppendSlice(src, dst))
+				default:
+					panic("override mode must be 'copy' or 'append' (default). I don't know how to '" + tag + "'.")
+				}
+			}
+		default:
+			panic("unknown field type : " + kind.String())
+		}
 	}
 }
 
@@ -186,11 +146,11 @@ func (spec *TargetSpec) resolveInherits() error {
 		if err != nil {
 			return err
 		}
-		newSpec.copyProperties(subtarget)
+		newSpec.overrideProperties(subtarget)
 	}
 
 	// When all properties are loaded, make sure they are properly inherited.
-	newSpec.copyProperties(spec)
+	newSpec.overrideProperties(spec)
 	*spec = *newSpec
 
 	return nil
@@ -256,6 +216,7 @@ func LoadTarget(target string) (*TargetSpec, error) {
 		}
 		goarch := map[string]string{ // map from LLVM arch to Go arch
 			"i386":    "386",
+			"i686":    "386",
 			"x86_64":  "amd64",
 			"aarch64": "arm64",
 			"armv7":   "arm",
@@ -271,39 +232,40 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 	// No target spec available. Use the default one, useful on most systems
 	// with a regular OS.
 	spec := TargetSpec{
-		Triple:      triple,
-		GOOS:        goos,
-		GOARCH:      goarch,
-		BuildTags:   []string{goos, goarch},
-		Compiler:    "clang",
-		Linker:      "cc",
-		CFlags:      []string{"--target=" + triple},
-		GDB:         "gdb",
-		PortReset:   "false",
-		FlashMethod: "native",
+		Triple:    triple,
+		GOOS:      goos,
+		GOARCH:    goarch,
+		BuildTags: []string{goos, goarch},
+		Compiler:  "clang",
+		Linker:    "cc",
+		CFlags:    []string{"--target=" + triple},
+		GDB:       "gdb",
+		PortReset: "false",
 	}
 	if goos == "darwin" {
 		spec.LDFlags = append(spec.LDFlags, "-Wl,-dead_strip")
 	} else {
 		spec.LDFlags = append(spec.LDFlags, "-no-pie", "-Wl,--gc-sections") // WARNING: clang < 5.0 requires -nopie
 	}
+	if goarch != "wasm" {
+		spec.ExtraFiles = append(spec.ExtraFiles, "src/runtime/gc_"+goarch+".S")
+	}
 	if goarch != runtime.GOARCH {
 		// Some educated guesses as to how to invoke helper programs.
+		spec.GDB = "gdb-multiarch"
 		if goarch == "arm" && goos == "linux" {
 			spec.CFlags = append(spec.CFlags, "--sysroot=/usr/arm-linux-gnueabihf")
 			spec.Linker = "arm-linux-gnueabihf-gcc"
-			spec.GDB = "arm-linux-gnueabihf-gdb"
 			spec.Emulator = []string{"qemu-arm", "-L", "/usr/arm-linux-gnueabihf"}
 		}
 		if goarch == "arm64" && goos == "linux" {
 			spec.CFlags = append(spec.CFlags, "--sysroot=/usr/aarch64-linux-gnu")
 			spec.Linker = "aarch64-linux-gnu-gcc"
-			spec.GDB = "aarch64-linux-gnu-gdb"
 			spec.Emulator = []string{"qemu-aarch64", "-L", "/usr/aarch64-linux-gnu"}
 		}
-		if goarch == "386" {
-			spec.CFlags = []string{"-m32"}
-			spec.LDFlags = []string{"-m32"}
+		if goarch == "386" && runtime.GOARCH == "amd64" {
+			spec.CFlags = append(spec.CFlags, "-m32")
+			spec.LDFlags = append(spec.LDFlags, "-m32")
 		}
 	}
 	return &spec, nil

compileopts/target_test.go

@@ -1,6 +1,9 @@
 package compileopts
 
-import "testing"
+import (
+	"reflect"
+	"testing"
+)
 
 func TestLoadTarget(t *testing.T) {
 	_, err := LoadTarget("arduino")
@@ -17,3 +20,67 @@ func TestLoadTarget(t *testing.T) {
 		t.Error("LoadTarget failed for wrong reason:", err)
 	}
 }
+
+func TestOverrideProperties(t *testing.T) {
+	baseAutoStackSize := true
+	base := &TargetSpec{
+		GOOS:             "baseGoos",
+		CPU:              "baseCpu",
+		Features:         []string{"bf1", "bf2"},
+		BuildTags:        []string{"bt1", "bt2"},
+		Emulator:         []string{"be1", "be2"},
+		DefaultStackSize: 42,
+		AutoStackSize:    &baseAutoStackSize,
+	}
+	childAutoStackSize := false
+	child := &TargetSpec{
+		GOOS:             "",
+		CPU:              "chlidCpu",
+		Features:         []string{"cf1", "cf2"},
+		Emulator:         []string{"ce1", "ce2"},
+		AutoStackSize:    &childAutoStackSize,
+		DefaultStackSize: 64,
+	}
+
+	base.overrideProperties(child)
+
+	if base.GOOS != "baseGoos" {
+		t.Errorf("Overriding failed : got %v", base.GOOS)
+	}
+	if base.CPU != "chlidCpu" {
+		t.Errorf("Overriding failed : got %v", base.CPU)
+	}
+	if !reflect.DeepEqual(base.Features, []string{"cf1", "cf2", "bf1", "bf2"}) {
+		t.Errorf("Overriding failed : got %v", base.Features)
+	}
+	if !reflect.DeepEqual(base.BuildTags, []string{"bt1", "bt2"}) {
+		t.Errorf("Overriding failed : got %v", base.BuildTags)
+	}
+	if !reflect.DeepEqual(base.Emulator, []string{"ce1", "ce2"}) {
+		t.Errorf("Overriding failed : got %v", base.Emulator)
+	}
+	if *base.AutoStackSize != false {
+		t.Errorf("Overriding failed : got %v", base.AutoStackSize)
+	}
+	if base.DefaultStackSize != 64 {
+		t.Errorf("Overriding failed : got %v", base.DefaultStackSize)
+	}
+
+	baseAutoStackSize = true
+	base = &TargetSpec{
+		AutoStackSize:    &baseAutoStackSize,
+		DefaultStackSize: 42,
+	}
+	child = &TargetSpec{
+		AutoStackSize:    nil,
+		DefaultStackSize: 0,
+	}
+	base.overrideProperties(child)
+	if *base.AutoStackSize != true {
+		t.Errorf("Overriding failed : got %v", base.AutoStackSize)
+	}
+	if base.DefaultStackSize != 42 {
+		t.Errorf("Overriding failed : got %v", base.DefaultStackSize)
+	}
+
+}

compiler/compiler.go

@@ -5,18 +5,15 @@ import (
 	"errors"
 	"fmt"
 	"go/ast"
-	"go/build"
 	"go/constant"
 	"go/token"
 	"go/types"
-	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
 
 	"github.com/tinygo-org/tinygo/compileopts"
 	"github.com/tinygo-org/tinygo/compiler/llvmutil"
-	"github.com/tinygo-org/tinygo/goenv"
 	"github.com/tinygo-org/tinygo/ir"
 	"github.com/tinygo-org/tinygo/loader"
 	"golang.org/x/tools/go/ssa"
@@ -130,6 +127,28 @@ func NewTargetMachine(config *compileopts.Config) (llvm.TargetMachine, error) {
 	return machine, nil
 }
 
+// CompilerOutput is returned from the Compile() call. It contains the compile
+// output and information necessary to continue to compile and link the program.
+type CompilerOutput struct {
+	// The LLVM module that contains the compiled but not optimized LLVM module
+	// for all the Go code in the program.
+	Mod llvm.Module
+
+	// ExtraFiles is a list of C source files included in packages that should
+	// be built and linked together with the main executable to form one
+	// program. They can be used from CGo, for example.
+	ExtraFiles []string
+
+	// ExtraLDFlags are linker flags obtained during CGo processing. These flags
+	// must be passed to the linker which links the entire executable.
+	ExtraLDFlags []string
+
+	// MainDir is the absolute directory path to the directory of the main
+	// package. This is useful for testing: tests must be run in the package
+	// directory that is being tested.
+	MainDir string
+}
+
 // Compile the given package path or .go file path. Return an error when this
 // fails (in any stage). If successful it returns the LLVM module and a list of
 // extra C files to be compiled. If not, one or more errors will be returned.
@@ -138,7 +157,7 @@ func NewTargetMachine(config *compileopts.Config) (llvm.TargetMachine, error) {
 // violation. Eventually, this Compile function should only compile a single
 // package and not the whole program, and loading of the program (including CGo
 // processing) should be moved outside the compiler package.
-func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Config) (mod llvm.Module, extrafiles []string, extraldflags []string, errors []error) {
+func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Config) (output CompilerOutput, errors []error) {
 	c := &compilerContext{
 		Config:     config,
 		difiles:    make(map[string]llvm.Metadata),
@@ -154,6 +173,7 @@ func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Con
 	if c.Debug() {
 		c.dibuilder = llvm.NewDIBuilder(c.mod)
 	}
+	output.Mod = c.mod
 
 	c.uintptrType = c.ctx.IntType(c.targetData.PointerSize() * 8)
 	if c.targetData.PointerSize() <= 4 {
@@ -172,55 +192,29 @@ func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Con
 	c.funcPtrAddrSpace = dummyFunc.Type().PointerAddressSpace()
 	dummyFunc.EraseFromParentAsFunction()
 
-	wd, err := os.Getwd()
+	lprogram, err := loader.Load(c.Config, []string{pkgName}, c.ClangHeaders, types.Config{
+		Sizes: &stdSizes{
+			IntSize:  int64(c.targetData.TypeAllocSize(c.intType)),
+			PtrSize:  int64(c.targetData.PointerSize()),
+			MaxAlign: int64(c.targetData.PrefTypeAlignment(c.i8ptrType)),
+		}})
 	if err != nil {
-		return c.mod, nil, nil, []error{err}
-	}
-	goroot, err := loader.GetCachedGoroot(c.Config)
-	if err != nil {
-		return c.mod, nil, nil, []error{err}
-	}
-	lprogram := &loader.Program{
-		Build: &build.Context{
-			GOARCH:      c.GOARCH(),
-			GOOS:        c.GOOS(),
-			GOROOT:      goroot,
-			GOPATH:      goenv.Get("GOPATH"),
-			CgoEnabled:  c.CgoEnabled(),
-			UseAllFiles: false,
-			Compiler:    "gc", // must be one of the recognized compilers
-			BuildTags:   c.BuildTags(),
-		},
-		Tests: c.TestConfig.CompileTestBinary,
-		TypeChecker: types.Config{
-			Sizes: &stdSizes{
-				IntSize:  int64(c.targetData.TypeAllocSize(c.intType)),
-				PtrSize:  int64(c.targetData.PointerSize()),
-				MaxAlign: int64(c.targetData.PrefTypeAlignment(c.i8ptrType)),
-			},
-		},
-		Dir:          wd,
-		TINYGOROOT:   goenv.Get("TINYGOROOT"),
-		CFlags:       c.CFlags(),
-		ClangHeaders: c.ClangHeaders,
-	}
-
-	err = lprogram.Load(pkgName)
-	if err != nil {
-		return c.mod, nil, nil, []error{err}
+		return output, []error{err}
 	}
 
 	err = lprogram.Parse()
 	if err != nil {
-		return c.mod, nil, nil, []error{err}
+		return output, []error{err}
 	}
+	output.ExtraLDFlags = lprogram.LDFlags
+	output.MainDir = lprogram.MainPkg().Dir
 
 	c.ir = ir.NewProgram(lprogram)
 
 	// Run a simple dead code elimination pass.
 	err = c.ir.SimpleDCE()
 	if err != nil {
-		return c.mod, nil, nil, []error{err}
+		return output, []error{err}
 	}
 
 	// Initialize debug information.
@@ -359,17 +353,13 @@ func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Con
 	}
 
 	// Gather the list of (C) file paths that should be included in the build.
-	var extraFiles []string
 	for _, pkg := range c.ir.LoaderProgram.Sorted() {
-		for _, file := range pkg.OtherFiles {
-			switch strings.ToLower(filepath.Ext(file)) {
-			case ".c":
-				extraFiles = append(extraFiles, file)
-			}
+		for _, filename := range pkg.CFiles {
+			output.ExtraFiles = append(output.ExtraFiles, filepath.Join(pkg.Dir, filename))
 		}
 	}
 
-	return c.mod, extraFiles, lprogram.LDFlags, c.diagnostics
+	return output, c.diagnostics
 }
 
 // getLLVMRuntimeType obtains a named type from the runtime package and returns
@@ -1346,12 +1336,14 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 			return b.createMemoryCopyCall(fn, instr.Args)
 		case name == "runtime.memzero":
 			return b.createMemoryZeroCall(instr.Args)
-		case name == "device.Asm" || name == "device/arm.Asm" || name == "device/avr.Asm" || name == "device/riscv.Asm":
+		case name == "device.Asm" || name == "device/arm.Asm" || name == "device/arm64.Asm" || name == "device/avr.Asm" || name == "device/riscv.Asm":
 			return b.createInlineAsm(instr.Args)
-		case name == "device.AsmFull" || name == "device/arm.AsmFull" || name == "device/avr.AsmFull" || name == "device/riscv.AsmFull":
+		case name == "device.AsmFull" || name == "device/arm.AsmFull" || name == "device/arm64.AsmFull" || name == "device/avr.AsmFull" || name == "device/riscv.AsmFull":
 			return b.createInlineAsmFull(instr)
 		case strings.HasPrefix(name, "device/arm.SVCall"):
 			return b.emitSVCall(instr.Args)
+		case strings.HasPrefix(name, "device/arm64.SVCall"):
+			return b.emitSV64Call(instr.Args)
 		case strings.HasPrefix(name, "(device/riscv.CSR)."):
 			return b.emitCSROperation(instr)
 		case strings.HasPrefix(name, "syscall.Syscall"):
@@ -2054,17 +2046,17 @@ func (b *builder) createBinOp(op token.Token, typ, ytyp types.Type, x, y llvm.Va
 			case token.QUO: // /
 				return b.CreateFDiv(x, y, ""), nil
 			case token.EQL: // ==
-				return b.CreateFCmp(llvm.FloatUEQ, x, y, ""), nil
+				return b.CreateFCmp(llvm.FloatOEQ, x, y, ""), nil
 			case token.NEQ: // !=
 				return b.CreateFCmp(llvm.FloatUNE, x, y, ""), nil
 			case token.LSS: // <
-				return b.CreateFCmp(llvm.FloatULT, x, y, ""), nil
+				return b.CreateFCmp(llvm.FloatOLT, x, y, ""), nil
 			case token.LEQ: // <=
-				return b.CreateFCmp(llvm.FloatULE, x, y, ""), nil
+				return b.CreateFCmp(llvm.FloatOLE, x, y, ""), nil
 			case token.GTR: // >
-				return b.CreateFCmp(llvm.FloatUGT, x, y, ""), nil
+				return b.CreateFCmp(llvm.FloatOGT, x, y, ""), nil
 			case token.GEQ: // >=
-				return b.CreateFCmp(llvm.FloatUGE, x, y, ""), nil
+				return b.CreateFCmp(llvm.FloatOGE, x, y, ""), nil
 			default:
 				panic("binop on float: " + op.String())
 			}
@@ -2588,7 +2580,17 @@ func (b *builder) createUnOp(unop *ssa.UnOp) (llvm.Value, error) {
 			if typ.Info()&types.IsInteger != 0 {
 				return b.CreateSub(llvm.ConstInt(x.Type(), 0, false), x, ""), nil
 			} else if typ.Info()&types.IsFloat != 0 {
-				return b.CreateFSub(llvm.ConstFloat(x.Type(), 0.0), x, ""), nil
+				return b.CreateFNeg(x, ""), nil
+			} else if typ.Info()&types.IsComplex != 0 {
+				// Negate both components of the complex number.
+				r := b.CreateExtractValue(x, 0, "r")
+				i := b.CreateExtractValue(x, 1, "i")
+				r = b.CreateFNeg(r, "")
+				i = b.CreateFNeg(i, "")
+				cplx := llvm.Undef(x.Type())
+				cplx = b.CreateInsertValue(cplx, r, 0, "")
+				cplx = b.CreateInsertValue(cplx, i, 1, "")
+				return cplx, nil
 			} else {
 				return llvm.Value{}, b.makeError(unop.Pos(), "todo: unknown basic type for negate: "+typ.String())
 			}

compiler/goroutine.go

@@ -19,16 +19,30 @@ import (
 // Because a go statement doesn't return anything, return undef.
 func (b *builder) createGoInstruction(funcPtr llvm.Value, params []llvm.Value, prefix string, pos token.Pos) llvm.Value {
 	paramBundle := b.emitPointerPack(params)
-	var callee llvm.Value
+	var callee, stackSize llvm.Value
 	switch b.Scheduler() {
 	case "none", "tasks":
 		callee = b.createGoroutineStartWrapper(funcPtr, prefix, pos)
+		if b.AutomaticStackSize() {
+			// The stack size is not known until after linking. Call a dummy
+			// function that will be replaced with a load from a special ELF
+			// section that contains the stack size (and is modified after
+			// linking).
+			stackSize = b.createCall(b.mod.NamedFunction("internal/task.getGoroutineStackSize"), []llvm.Value{callee, llvm.Undef(b.i8ptrType), llvm.Undef(b.i8ptrType)}, "stacksize")
+		} else {
+			// The stack size is fixed at compile time. By emitting it here as a
+			// constant, it can be optimized.
+			stackSize = llvm.ConstInt(b.uintptrType, b.Target.DefaultStackSize, false)
+		}
 	case "coroutines":
 		callee = b.CreatePtrToInt(funcPtr, b.uintptrType, "")
+		// There is no goroutine stack size: coroutines are used instead of
+		// stacks.
+		stackSize = llvm.Undef(b.uintptrType)
 	default:
 		panic("unreachable")
 	}
-	b.createCall(b.mod.NamedFunction("internal/task.start"), []llvm.Value{callee, paramBundle, llvm.Undef(b.i8ptrType), llvm.ConstPointerNull(b.i8ptrType)}, "")
+	b.createCall(b.mod.NamedFunction("internal/task.start"), []llvm.Value{callee, paramBundle, stackSize, llvm.Undef(b.i8ptrType), llvm.ConstPointerNull(b.i8ptrType)}, "")
 	return llvm.Undef(funcPtr.Type().ElementType().ReturnType())
 }
 
@@ -67,8 +81,9 @@ func (c *compilerContext) createGoroutineStartWrapper(fn llvm.Value, prefix stri
 		// Create the wrapper.
 		wrapperType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.i8ptrType}, false)
 		wrapper = llvm.AddFunction(c.mod, name+"$gowrapper", wrapperType)
-		wrapper.SetLinkage(llvm.PrivateLinkage)
+		wrapper.SetLinkage(llvm.InternalLinkage)
 		wrapper.SetUnnamedAddr(true)
+		wrapper.AddAttributeAtIndex(-1, c.ctx.CreateStringAttribute("tinygo-gowrapper", name))
 		entry := c.ctx.AddBasicBlock(wrapper, "entry")
 		builder.SetInsertPointAtEnd(entry)
 
@@ -125,6 +140,7 @@ func (c *compilerContext) createGoroutineStartWrapper(fn llvm.Value, prefix stri
 		wrapper = llvm.AddFunction(c.mod, prefix+".gowrapper", wrapperType)
 		wrapper.SetLinkage(llvm.InternalLinkage)
 		wrapper.SetUnnamedAddr(true)
+		wrapper.AddAttributeAtIndex(-1, c.ctx.CreateStringAttribute("tinygo-gowrapper", ""))
 		entry := c.ctx.AddBasicBlock(wrapper, "entry")
 		builder.SetInsertPointAtEnd(entry)
 

compiler/inlineasm.go

@@ -163,6 +163,44 @@ func (b *builder) emitSVCall(args []ssa.Value) (llvm.Value, error) {
 	return b.CreateCall(target, llvmArgs, ""), nil
 }
 
+// This is a compiler builtin which emits an inline SVCall instruction. It can
+// be one of:
+//
+//     func SVCall0(num uintptr) uintptr
+//     func SVCall1(num uintptr, a1 interface{}) uintptr
+//     func SVCall2(num uintptr, a1, a2 interface{}) uintptr
+//     func SVCall3(num uintptr, a1, a2, a3 interface{}) uintptr
+//     func SVCall4(num uintptr, a1, a2, a3, a4 interface{}) uintptr
+//
+// The num parameter must be a constant. All other parameters may be any scalar
+// value supported by LLVM inline assembly.
+// Same as emitSVCall but for AArch64
+func (b *builder) emitSV64Call(args []ssa.Value) (llvm.Value, error) {
+	num, _ := constant.Uint64Val(args[0].(*ssa.Const).Value)
+	llvmArgs := []llvm.Value{}
+	argTypes := []llvm.Type{}
+	asm := "svc #" + strconv.FormatUint(num, 10)
+	constraints := "={x0}"
+	for i, arg := range args[1:] {
+		arg = arg.(*ssa.MakeInterface).X
+		if i == 0 {
+			constraints += ",0"
+		} else {
+			constraints += ",{x" + strconv.Itoa(i) + "}"
+		}
+		llvmValue := b.getValue(arg)
+		llvmArgs = append(llvmArgs, llvmValue)
+		argTypes = append(argTypes, llvmValue.Type())
+	}
+	// Implement the ARM64 calling convention by marking x1-x7 as
+	// clobbered. x0 is used as an output register so doesn't have to be
+	// marked as clobbered.
+	constraints += ",~{x1},~{x2},~{x3},~{x4},~{x5},~{x6},~{x7}"
+	fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
+	target := llvm.InlineAsm(fnType, asm, constraints, true, false, 0)
+	return b.CreateCall(target, llvmArgs, ""), nil
+}
+
 // This is a compiler builtin which emits CSR instructions. It can be one of:
 //
 //     func (csr CSR) Get() uintptr

go.mod

@@ -4,11 +4,11 @@ go 1.11
 
 require (
 	github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2
-	github.com/chromedp/cdproto v0.0.0-20200116234248-4da64dd111ac
-	github.com/chromedp/chromedp v0.5.3
+	github.com/chromedp/cdproto v0.0.0-20200709115526-d1f6fc58448b
+	github.com/chromedp/chromedp v0.5.4-0.20200303084119-2bb39134ab9e
 	github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf
 	github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892
 	go.bug.st/serial v1.0.0
 	golang.org/x/tools v0.0.0-20200216192241-b320d3a0f5a2
-	tinygo.org/x/go-llvm v0.0.0-20200503225853-345b2947b59d
+	tinygo.org/x/go-llvm v0.0.0-20201104183921-570e7a6841d9
 )

go.sum

@@ -1,9 +1,10 @@
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2 h1:oMCHnXa6CCCafdPDbMh/lWRhRByN0VFLvv+g+ayx1SI=
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2/go.mod h1:PkYb9DJNAwrSvRx5DYA+gUcOIgTGVMNkfSCbZM8cWpI=
-github.com/chromedp/cdproto v0.0.0-20200116234248-4da64dd111ac h1:T7V5BXqnYd55Hj/g5uhDYumg9Fp3rMTS6bykYtTIFX4=
 github.com/chromedp/cdproto v0.0.0-20200116234248-4da64dd111ac/go.mod h1:PfAWWKJqjlGFYJEidUM6aVIWPr0EpobeyVWEEmplX7g=
-github.com/chromedp/chromedp v0.5.3 h1:F9LafxmYpsQhWQBdCs+6Sret1zzeeFyHS5LkRF//Ffg=
-github.com/chromedp/chromedp v0.5.3/go.mod h1:YLdPtndaHQ4rCpSpBG+IPpy9JvX0VD+7aaLxYgYj28w=
+github.com/chromedp/cdproto v0.0.0-20200709115526-d1f6fc58448b h1:LF+GRwyzxrO3MUzPvejv+yBup0lNG+/QdIRrkxOPseA=
+github.com/chromedp/cdproto v0.0.0-20200709115526-d1f6fc58448b/go.mod h1:E6LPWRdIJc11h/di5p0rwvRmUYbhGpBEH7ZbPfzDIOE=
+github.com/chromedp/chromedp v0.5.4-0.20200303084119-2bb39134ab9e h1:Hv0JVyHhbIXb9NiYQe4NsrfgrSofAp0q2FnhhJOXgi8=
+github.com/chromedp/chromedp v0.5.4-0.20200303084119-2bb39134ab9e/go.mod h1:vmQMRHFZrY3T+Jv51T0n87OK/i6bK+5P9a+Fg5jPwgQ=
 github.com/creack/goselect v0.1.1 h1:tiSSgKE1eJtxs1h/VgGQWuXUP0YS4CDIFMp6vaI1ls0=
 github.com/creack/goselect v0.1.1/go.mod h1:a/NhLweNvqIYMuxcMOuWY516Cimucms3DglDzQP3hKY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -11,14 +12,15 @@ github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee h1:s+21KNqlpePfkah
 github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee/go.mod h1:L0fX3K22YWvt/FAX9NnzrNzcI4wNYi9Yku4O0LKYflo=
 github.com/gobwas/pool v0.2.0 h1:QEmUOlnSjWtnpRGHF3SauEiOsy82Cup83Vf2LcMlnc8=
 github.com/gobwas/pool v0.2.0/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
-github.com/gobwas/ws v1.0.2 h1:CoAavW/wd/kulfZmSIBt6p24n4j7tHgNVCjsfHVNUbo=
-github.com/gobwas/ws v1.0.2/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM=
+github.com/gobwas/ws v1.0.3 h1:ZOigqf7iBxkA4jdQ3am7ATzdlOFp9YzA6NmuvEEZc9g=
+github.com/gobwas/ws v1.0.3/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM=
 github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf h1:7+FW5aGwISbqUtkfmIpZJGRgNFg2ioYPvFaUxdqpDsg=
 github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf/go.mod h1:RpwtwJQFrIEPstU94h88MWPXP2ektJZ8cZ0YntAmXiE=
 github.com/knq/sysutil v0.0.0-20191005231841-15668db23d08 h1:V0an7KRw92wmJysvFvtqtKMAPmvS5O0jtB0nYo6t+gs=
 github.com/knq/sysutil v0.0.0-20191005231841-15668db23d08/go.mod h1:dFWs1zEqDjFtnBXsd1vPOZaLsESovai349994nHx3e0=
-github.com/mailru/easyjson v0.7.0 h1:aizVhC/NAAcKWb+5QsU1iNOZb4Yws5UO2I+aIprQITM=
 github.com/mailru/easyjson v0.7.0/go.mod h1:KAzv3t3aY1NaHWoQz1+4F1ccyAH66Jk7yos7ldAVICs=
+github.com/mailru/easyjson v0.7.1 h1:mdxE1MF9o53iCb2Ghj1VfWvh7ZOwHpnVG/xwXrV90U8=
+github.com/mailru/easyjson v0.7.1/go.mod h1:KAzv3t3aY1NaHWoQz1+4F1ccyAH66Jk7yos7ldAVICs=
 github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892 h1:6J+qramlHVLmiBOgRiBOnQkno8uprqG6YFFQTt6uYIw=
 github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892/go.mod h1:Pb6XcsXyropB9LNHhnqaknG/vEwYztLkQzVCHv8sQ3M=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@@ -46,5 +48,5 @@ golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbO
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-tinygo.org/x/go-llvm v0.0.0-20200503225853-345b2947b59d h1:hcX7vpB067GWM/EH4sGGOti0PMgIx+0bbZwUXctOIvE=
-tinygo.org/x/go-llvm v0.0.0-20200503225853-345b2947b59d/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20201104183921-570e7a6841d9 h1:l2kTQOhqEoeDTK3ckUnwReOQwMPUmURMIdjJbeAuDT4=
+tinygo.org/x/go-llvm v0.0.0-20201104183921-570e7a6841d9/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=

goenv/version.go

@@ -12,7 +12,7 @@ import (
 
 // Version of TinyGo.
 // Update this value before release of new version of software.
-const Version = "0.14.0"
+const Version = "0.16.0"
 
 // GetGorootVersion returns the major and minor version for a given GOROOT path.
 // If the goroot cannot be determined, (0, 0) is returned.

interp/errors.go

@@ -47,10 +47,12 @@ func (e *Error) Error() string {
 // location of the instruction. The location information may not be complete as
 // it depends on debug information in the IR.
 func (e *evalPackage) errorAt(inst llvm.Value, err error) *Error {
+	pos := getPosition(inst)
 	return &Error{
 		ImportPath: e.packagePath,
-		Pos:        getPosition(inst),
+		Pos:        pos,
 		Err:        err,
+		Traceback:  []ErrorLine{{pos, inst}},
 	}
 }
 

interp/frame.go

@@ -95,7 +95,11 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 			if !operand.IsConstant() || inst.IsVolatile() || (!operand.Underlying.IsAConstantExpr().IsNil() && operand.Underlying.Opcode() == llvm.BitCast) {
 				value = fr.builder.CreateLoad(operand.Value(), inst.Name())
 			} else {
-				value = operand.Load()
+				var err error
+				value, err = operand.Load()
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 			}
 			if value.Type() != inst.Type() {
 				return nil, nil, fr.errorAt(inst, errors.New("interp: load: type does not match"))
@@ -107,7 +111,10 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 			if inst.IsVolatile() {
 				fr.builder.CreateStore(value.Value(), ptr.Value())
 			} else {
-				ptr.Store(value.Value())
+				err := ptr.Store(value.Value())
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 			}
 		case !inst.IsAGetElementPtrInst().IsNil():
 			value := fr.getLocal(inst.Operand(0))
@@ -308,7 +315,10 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				}
 				// "key" is a Go string value, which in the TinyGo calling convention is split up
 				// into separate pointer and length parameters.
-				m.PutString(keyBuf, keyLen, valPtr)
+				err := m.PutString(keyBuf, keyLen, valPtr)
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 			case callee.Name() == "runtime.hashmapBinarySet":
 				// set a binary (int etc.) key in the map
 				keyBuf := fr.getLocal(inst.Operand(1)).(*LocalValue)
@@ -329,15 +339,24 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 					fr.builder.CreateCall(callee, llvmParams, "")
 					continue
 				}
-				m.PutBinary(keyBuf, valPtr)
+				err := m.PutBinary(keyBuf, valPtr)
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 			case callee.Name() == "runtime.stringConcat":
 				// adding two strings together
 				buf1Ptr := fr.getLocal(inst.Operand(0))
 				buf1Len := fr.getLocal(inst.Operand(1))
 				buf2Ptr := fr.getLocal(inst.Operand(2))
 				buf2Len := fr.getLocal(inst.Operand(3))
-				buf1 := getStringBytes(buf1Ptr, buf1Len.Value())
-				buf2 := getStringBytes(buf2Ptr, buf2Len.Value())
+				buf1, err := getStringBytes(buf1Ptr, buf1Len.Value())
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
+				buf2, err := getStringBytes(buf2Ptr, buf2Len.Value())
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 				result := []byte(string(buf1) + string(buf2))
 				vals := make([]llvm.Value, len(result))
 				for i := range vals {
@@ -401,9 +420,15 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 					return nil, nil, fr.errorAt(inst, errors.New("interp: trying to copy a slice with negative length?"))
 				}
 				for i := int64(0); i < length; i++ {
-					var err error
 					// *dst = *src
-					dstArray.Store(srcArray.Load())
+					val, err := srcArray.Load()
+					if err != nil {
+						return nil, nil, fr.errorAt(inst, err)
+					}
+					err = dstArray.Store(val)
+					if err != nil {
+						return nil, nil, fr.errorAt(inst, err)
+					}
 					// dst++
 					dstArrayValue, err := dstArray.GetElementPtr([]uint32{1})
 					if err != nil {
@@ -421,7 +446,10 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				// convert a string to a []byte
 				bufPtr := fr.getLocal(inst.Operand(0))
 				bufLen := fr.getLocal(inst.Operand(1))
-				result := getStringBytes(bufPtr, bufLen.Value())
+				result, err := getStringBytes(bufPtr, bufLen.Value())
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 				vals := make([]llvm.Value, len(result))
 				for i := range vals {
 					vals[i] = llvm.ConstInt(fr.Mod.Context().Int8Type(), uint64(result[i]), false)

interp/interp_test.go

@@ -3,6 +3,7 @@ package interp
 import (
 	"io/ioutil"
 	"os"
+	"regexp"
 	"strings"
 	"testing"
 
@@ -66,6 +67,8 @@ func runTest(t *testing.T, pathPrefix string) {
 	}
 }
 
+var alignRegexp = regexp.MustCompile(", align [0-9]+$")
+
 // fuzzyEqualIR returns true if the two LLVM IR strings passed in are roughly
 // equal. That means, only relevant lines are compared (excluding comments
 // etc.).
@@ -75,8 +78,18 @@ func fuzzyEqualIR(s1, s2 string) bool {
 	if len(lines1) != len(lines2) {
 		return false
 	}
-	for i, line := range lines1 {
-		if line != lines2[i] {
+	for i, line1 := range lines1 {
+		line2 := lines2[i]
+		match1 := alignRegexp.MatchString(line1)
+		match2 := alignRegexp.MatchString(line2)
+		if match1 != match2 {
+			// Only one of the lines has the align keyword. Remove it.
+			// This is a change to make the test work in both LLVM 10 and LLVM
+			// 11 (LLVM 11 appears to automatically add alignment everywhere).
+			line1 = alignRegexp.ReplaceAllString(line1, "")
+			line2 = alignRegexp.ReplaceAllString(line2, "")
+		}
+		if line1 != line2 {
 			return false
 		}
 	}

interp/utils.go

@@ -1,6 +1,8 @@
 package interp
 
 import (
+	"errors"
+
 	"tinygo.org/x/go-llvm"
 )
 
@@ -18,20 +20,23 @@ func getUses(value llvm.Value) []llvm.Value {
 
 // getStringBytes loads the byte slice of a Go string represented as a
 // {ptr, len} pair.
-func getStringBytes(strPtr Value, strLen llvm.Value) []byte {
+func getStringBytes(strPtr Value, strLen llvm.Value) ([]byte, error) {
 	if !strLen.IsConstant() {
-		panic("getStringBytes with a non-constant length")
+		return nil, errors.New("getStringBytes with a non-constant length")
 	}
 	buf := make([]byte, strLen.ZExtValue())
 	for i := range buf {
 		gep, err := strPtr.GetElementPtr([]uint32{uint32(i)})
 		if err != nil {
-			panic(err) // TODO
+			return nil, err
+		}
+		c, err := gep.Load()
+		if err != nil {
+			return nil, err
 		}
-		c := gep.Load()
 		buf[i] = byte(c.ZExtValue())
 	}
-	return buf
+	return buf, nil
 }
 
 // getLLVMIndices converts an []uint32 into an []llvm.Value, for use in

interp/values.go

@@ -15,8 +15,8 @@ type Value interface {
 	Value() llvm.Value                     // returns a LLVM value
 	Type() llvm.Type                       // equal to Value().Type()
 	IsConstant() bool                      // returns true if this value is a constant value
-	Load() llvm.Value                      // dereference a pointer
-	Store(llvm.Value)                      // store to a pointer
+	Load() (llvm.Value, error)             // dereference a pointer
+	Store(llvm.Value) error                // store to a pointer
 	GetElementPtr([]uint32) (Value, error) // returns an interior pointer
 	String() string                        // string representation, for debugging
 }
@@ -44,29 +44,32 @@ func (v *LocalValue) IsConstant() bool {
 }
 
 // Load loads a constant value if this is a constant pointer.
-func (v *LocalValue) Load() llvm.Value {
+func (v *LocalValue) Load() (llvm.Value, error) {
 	if !v.Underlying.IsAGlobalVariable().IsNil() {
-		return v.Underlying.Initializer()
+		return v.Underlying.Initializer(), nil
 	}
 	switch v.Underlying.Opcode() {
 	case llvm.GetElementPtr:
 		indices := v.getConstGEPIndices()
 		if indices[0] != 0 {
-			panic("invalid GEP")
+			return llvm.Value{}, errors.New("invalid GEP")
 		}
 		global := v.Eval.getValue(v.Underlying.Operand(0))
-		agg := global.Load()
-		return llvm.ConstExtractValue(agg, indices[1:])
+		agg, err := global.Load()
+		if err != nil {
+			return llvm.Value{}, err
+		}
+		return llvm.ConstExtractValue(agg, indices[1:]), nil
 	case llvm.BitCast:
-		panic("interp: load from a bitcast")
+		return llvm.Value{}, errors.New("interp: load from a bitcast")
 	default:
-		panic("interp: load from a constant")
+		return llvm.Value{}, errors.New("interp: load from a constant")
 	}
 }
 
 // Store stores to the underlying value if the value type is a pointer type,
-// otherwise it panics.
-func (v *LocalValue) Store(value llvm.Value) {
+// otherwise it returns an error.
+func (v *LocalValue) Store(value llvm.Value) error {
 	if !v.Underlying.IsAGlobalVariable().IsNil() {
 		if !value.IsConstant() {
 			v.MarkDirty()
@@ -74,26 +77,28 @@ func (v *LocalValue) Store(value llvm.Value) {
 		} else {
 			v.Underlying.SetInitializer(value)
 		}
-		return
+		return nil
 	}
 	if !value.IsConstant() {
 		v.MarkDirty()
 		v.Eval.builder.CreateStore(value, v.Underlying)
-		return
+		return nil
 	}
 	switch v.Underlying.Opcode() {
 	case llvm.GetElementPtr:
 		indices := v.getConstGEPIndices()
 		if indices[0] != 0 {
-			panic("invalid GEP")
+			return errors.New("invalid GEP")
 		}
 		global := &LocalValue{v.Eval, v.Underlying.Operand(0)}
-		agg := global.Load()
+		agg, err := global.Load()
+		if err != nil {
+			return err
+		}
 		agg = llvm.ConstInsertValue(agg, value, indices[1:])
-		global.Store(agg)
-		return
+		return global.Store(agg)
 	default:
-		panic("interp: store on a constant")
+		return errors.New("interp: store on a constant")
 	}
 }
 
@@ -225,7 +230,11 @@ func (v *MapValue) Value() llvm.Value {
 			keyPtr := llvm.ConstExtractValue(llvmKey, []uint32{0})
 			keyLen := llvm.ConstExtractValue(llvmKey, []uint32{1})
 			keyPtrVal := v.Eval.getValue(keyPtr)
-			keyBuf = getStringBytes(keyPtrVal, keyLen)
+			var err error
+			keyBuf, err = getStringBytes(keyPtrVal, keyLen)
+			if err != nil {
+				panic(err) // TODO
+			}
 		} else if key.Type().TypeKind() == llvm.IntegerTypeKind {
 			keyBuf = make([]byte, v.Eval.TargetData.TypeAllocSize(key.Type()))
 			n := key.Value().ZExtValue()
@@ -299,13 +308,15 @@ func (v *MapValue) IsConstant() bool {
 }
 
 // Load panics: maps are of reference type so cannot be dereferenced.
-func (v *MapValue) Load() llvm.Value {
+func (v *MapValue) Load() (llvm.Value, error) {
 	panic("interp: load from a map")
 }
 
-// Store panics: maps are of reference type so cannot be stored to.
-func (v *MapValue) Store(value llvm.Value) {
-	panic("interp: store on a map")
+// Store returns an error: maps are of reference type so cannot be stored to.
+func (v *MapValue) Store(value llvm.Value) error {
+	// This must be a bug, but it might be helpful to indicate the location
+	// anyway.
+	return errors.New("interp: store on a map")
 }
 
 // GetElementPtr panics: maps are of reference type so their (interior)
@@ -316,23 +327,26 @@ func (v *MapValue) GetElementPtr(indices []uint32) (Value, error) {
 
 // PutString does a map assign operation, assuming that the map is of type
 // map[string]T.
-func (v *MapValue) PutString(keyBuf, keyLen, valPtr *LocalValue) {
+func (v *MapValue) PutString(keyBuf, keyLen, valPtr *LocalValue) error {
 	if !v.Underlying.IsNil() {
-		panic("map already created")
+		return errors.New("map already created")
 	}
 
 	if valPtr.Underlying.Opcode() == llvm.BitCast {
 		valPtr = &LocalValue{v.Eval, valPtr.Underlying.Operand(0)}
 	}
-	value := valPtr.Load()
+	value, err := valPtr.Load()
+	if err != nil {
+		return err
+	}
 	if v.ValueType.IsNil() {
 		v.ValueType = value.Type()
 		if int(v.Eval.TargetData.TypeAllocSize(v.ValueType)) != v.ValueSize {
-			panic("interp: map store value type has the wrong size")
+			return errors.New("interp: map store value type has the wrong size")
 		}
 	} else {
 		if value.Type() != v.ValueType {
-			panic("interp: map store value type is inconsistent")
+			return errors.New("interp: map store value type is inconsistent")
 		}
 	}
 
@@ -345,26 +359,31 @@ func (v *MapValue) PutString(keyBuf, keyLen, valPtr *LocalValue) {
 	// TODO: avoid duplicate keys
 	v.Keys = append(v.Keys, &LocalValue{v.Eval, key})
 	v.Values = append(v.Values, &LocalValue{v.Eval, value})
+
+	return nil
 }
 
 // PutBinary does a map assign operation.
-func (v *MapValue) PutBinary(keyPtr, valPtr *LocalValue) {
+func (v *MapValue) PutBinary(keyPtr, valPtr *LocalValue) error {
 	if !v.Underlying.IsNil() {
-		panic("map already created")
+		return errors.New("map already created")
 	}
 
 	if valPtr.Underlying.Opcode() == llvm.BitCast {
 		valPtr = &LocalValue{v.Eval, valPtr.Underlying.Operand(0)}
 	}
-	value := valPtr.Load()
+	value, err := valPtr.Load()
+	if err != nil {
+		return err
+	}
 	if v.ValueType.IsNil() {
 		v.ValueType = value.Type()
 		if int(v.Eval.TargetData.TypeAllocSize(v.ValueType)) != v.ValueSize {
-			panic("interp: map store value type has the wrong size")
+			return errors.New("interp: map store value type has the wrong size")
 		}
 	} else {
 		if value.Type() != v.ValueType {
-			panic("interp: map store value type is inconsistent")
+			return errors.New("interp: map store value type is inconsistent")
 		}
 	}
 
@@ -375,21 +394,26 @@ func (v *MapValue) PutBinary(keyPtr, valPtr *LocalValue) {
 			keyPtr = &LocalValue{v.Eval, keyPtr.Underlying.Operand(0)}
 		}
 	}
-	key := keyPtr.Load()
+	key, err := keyPtr.Load()
+	if err != nil {
+		return err
+	}
 	if v.KeyType.IsNil() {
 		v.KeyType = key.Type()
 		if int(v.Eval.TargetData.TypeAllocSize(v.KeyType)) != v.KeySize {
-			panic("interp: map store key type has the wrong size")
+			return errors.New("interp: map store key type has the wrong size")
 		}
 	} else {
 		if key.Type() != v.KeyType {
-			panic("interp: map store key type is inconsistent")
+			return errors.New("interp: map store key type is inconsistent")
 		}
 	}
 
 	// TODO: avoid duplicate keys
 	v.Keys = append(v.Keys, &LocalValue{v.Eval, key})
 	v.Values = append(v.Values, &LocalValue{v.Eval, value})
+
+	return nil
 }
 
 // Get FNV-1a hash of this string.

ir/ir.go

@@ -67,7 +67,7 @@ func NewProgram(lprogram *loader.Program) *Program {
 	program := lprogram.LoadSSA()
 	program.Build()
 
-	mainPkg := program.ImportedPackage(lprogram.MainPkg.PkgPath)
+	mainPkg := program.ImportedPackage(lprogram.MainPkg().ImportPath)
 	if mainPkg == nil {
 		panic("could not find main package")
 	}
@@ -79,7 +79,7 @@ func NewProgram(lprogram *loader.Program) *Program {
 	}
 
 	for _, pkg := range lprogram.Sorted() {
-		p.AddPackage(program.ImportedPackage(pkg.PkgPath))
+		p.AddPackage(program.ImportedPackage(pkg.ImportPath))
 	}
 
 	return p

loader/errors.go

@@ -1,5 +1,7 @@
 package loader
 
+import "go/scanner"
+
 // Errors contains a list of parser errors or a list of typechecker errors for
 // the given package.
 type Errors struct {
@@ -10,3 +12,14 @@ type Errors struct {
 func (e Errors) Error() string {
 	return "could not compile: " + e.Errs[0].Error()
 }
+
+// Error is a regular error but with an added import stack. This is especially
+// useful for debugging import cycle errors.
+type Error struct {
+	ImportStack []string
+	Err         scanner.Error
+}
+
+func (e Error) Error() string {
+	return e.Err.Error()
+}

loader/goroot.go

@@ -8,19 +8,21 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
-	"math/rand"
 	"os"
 	"os/exec"
 	"path"
 	"path/filepath"
 	"runtime"
-	"strconv"
+	"sync"
 
 	"github.com/tinygo-org/tinygo/compileopts"
 	"github.com/tinygo-org/tinygo/goenv"
 )
 
+var gorootCreateMutex sync.Mutex
+
 // GetCachedGoroot creates a new GOROOT by merging both the standard GOROOT and
 // the GOROOT from TinyGo using lots of symbolic links.
 func GetCachedGoroot(config *compileopts.Config) (string, error) {
@@ -49,16 +51,29 @@ func GetCachedGoroot(config *compileopts.Config) (string, error) {
 	fmt.Fprintln(hash, tinygoroot)
 	gorootsHash := hash.Sum(nil)
 	gorootsHashHex := hex.EncodeToString(gorootsHash[:])
-	cachedgoroot := filepath.Join(goenv.Get("GOCACHE"), "goroot-"+version+"-"+gorootsHashHex)
+	cachedgorootName := "goroot-" + version + "-" + gorootsHashHex
+	cachedgoroot := filepath.Join(goenv.Get("GOCACHE"), cachedgorootName)
 	if needsSyscallPackage(config.BuildTags()) {
 		cachedgoroot += "-syscall"
 	}
 
+	// Do not try to create the cached GOROOT in parallel, that's only a waste
+	// of I/O bandwidth and thus speed. Instead, use a mutex to make sure only
+	// one goroutine does it at a time.
+	// This is not a way to ensure atomicity (a different TinyGo invocation
+	// could be creating the same directory), but instead a way to avoid
+	// creating it many times in parallel when running tests in parallel.
+	gorootCreateMutex.Lock()
+	defer gorootCreateMutex.Unlock()
+
 	if _, err := os.Stat(cachedgoroot); err == nil {
 		return cachedgoroot, nil
 	}
-	tmpgoroot := cachedgoroot + ".tmp" + strconv.Itoa(rand.Int())
-	err = os.MkdirAll(tmpgoroot, 0777)
+	err = os.MkdirAll(goenv.Get("GOCACHE"), 0777)
+	if err != nil {
+		return "", err
+	}
+	tmpgoroot, err := ioutil.TempDir(goenv.Get("GOCACHE"), cachedgorootName+".tmp")
 	if err != nil {
 		return "", err
 	}
@@ -85,6 +100,15 @@ func GetCachedGoroot(config *compileopts.Config) (string, error) {
 			// deleted by the defer above.
 			return cachedgoroot, nil
 		}
+		if runtime.GOOS == "windows" && os.IsPermission(err) {
+			// On Windows, a rename with a destination directory that already
+			// exists does not result in an IsExist error, but rather in an
+			// access denied error. To be sure, check for this case by checking
+			// whether the target directory exists.
+			if _, err := os.Stat(cachedgoroot); err == nil {
+				return cachedgoroot, nil
+			}
+		}
 		return "", err
 	}
 	return cachedgoroot, nil
@@ -165,7 +189,7 @@ func mergeDirectory(goroot, tinygoroot, tmpgoroot, importPath string, overrides
 // with the TinyGo version. This is the case on some targets.
 func needsSyscallPackage(buildTags []string) bool {
 	for _, tag := range buildTags {
-		if tag == "baremetal" || tag == "darwin" || tag == "nintendoswitch" {
+		if tag == "baremetal" || tag == "darwin" || tag == "nintendoswitch" || tag == "wasi" {
 			return true
 		}
 	}
@@ -188,7 +212,7 @@ func pathsToOverride(needsSyscallPackage bool) map[string]bool {
 		"reflect/":              false,
 		"runtime/":              false,
 		"sync/":                 true,
-		"testing/":              false,
+		"testing/":              true,
 	}
 	if needsSyscallPackage {
 		paths["syscall/"] = true // include syscall/js
@@ -228,10 +252,27 @@ func symlink(oldname, newname string) error {
 				return symlinkErr
 			}
 		} else {
-			// Make a hard link.
+			// Try making a hard link.
 			err := os.Link(oldname, newname)
 			if err != nil {
-				return symlinkErr
+				// Making a hardlink failed. Try copying the file as a last
+				// fallback.
+				inf, err := os.Open(oldname)
+				if err != nil {
+					return err
+				}
+				defer inf.Close()
+				outf, err := os.Create(newname)
+				if err != nil {
+					return err
+				}
+				defer outf.Close()
+				_, err = io.Copy(outf, inf)
+				if err != nil {
+					os.Remove(newname)
+					return err
+				}
+				// File was copied.
 			}
 		}
 		return nil // success

loader/list.go

@@ -0,0 +1,30 @@
+package loader
+
+import (
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+)
+
+// List returns a ready-to-run *exec.Cmd for running the `go list` command with
+// the configuration used for TinyGo.
+func List(config *compileopts.Config, extraArgs, pkgs []string) (*exec.Cmd, error) {
+	goroot, err := GetCachedGoroot(config)
+	if err != nil {
+		return nil, err
+	}
+	args := append([]string{"list"}, extraArgs...)
+	if len(config.BuildTags()) != 0 {
+		args = append(args, "-tags", strings.Join(config.BuildTags(), " "))
+	}
+	args = append(args, pkgs...)
+	cgoEnabled := "0"
+	if config.CgoEnabled() {
+		cgoEnabled = "1"
+	}
+	cmd := exec.Command("go", args...)
+	cmd.Env = append(os.Environ(), "GOROOT="+goroot, "GOOS="+config.GOOS(), "GOARCH="+config.GOARCH(), "CGO_ENABLED="+cgoEnabled)
+	return cmd, nil
+}

loader/loader.go

@@ -2,165 +2,212 @@ package loader
 
 import (
 	"bytes"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"go/ast"
-	"go/build"
 	"go/parser"
 	"go/scanner"
 	"go/token"
 	"go/types"
+	"io"
 	"os"
+	"os/exec"
 	"path/filepath"
-	"sort"
 	"strconv"
 	"strings"
-	"text/template"
+	"syscall"
 
 	"github.com/tinygo-org/tinygo/cgo"
+	"github.com/tinygo-org/tinygo/compileopts"
 	"github.com/tinygo-org/tinygo/goenv"
-	"golang.org/x/tools/go/packages"
 )
 
 // Program holds all packages and some metadata about the program as a whole.
 type Program struct {
-	Build        *build.Context
-	Tests        bool
-	Packages     map[string]*Package
-	MainPkg      *Package
-	sorted       []*Package
-	fset         *token.FileSet
-	TypeChecker  types.Config
-	Dir          string // current working directory (for error reporting)
-	TINYGOROOT   string // root of the TinyGo installation or root of the source code
-	CFlags       []string
-	LDFlags      []string
-	ClangHeaders string
+	config       *compileopts.Config
+	clangHeaders string
+	typeChecker  types.Config
+	goroot       string // synthetic GOROOT
+	workingDir   string
+
+	Packages map[string]*Package
+	sorted   []*Package
+	fset     *token.FileSet
+
+	// Information obtained during parsing.
+	LDFlags []string
+}
+
+// PackageJSON is a subset of the JSON struct returned from `go list`.
+type PackageJSON struct {
+	Dir        string
+	ImportPath string
+	ForTest    string
+
+	// Source files
+	GoFiles  []string
+	CgoFiles []string
+	CFiles   []string
+
+	// Dependency information
+	Imports []string
+
+	// Error information
+	Error *struct {
+		ImportStack []string
+		Pos         string
+		Err         string
+	}
 }
 
 // Package holds a loaded package, its imports, and its parsed files.
 type Package struct {
-	*Program
-	*packages.Package
-	Files []*ast.File
-	Pkg   *types.Package
-	types.Info
+	PackageJSON
+
+	program *Program
+	Files   []*ast.File
+	Pkg     *types.Package
+	info    types.Info
 }
 
 // Load loads the given package with all dependencies (including the runtime
 // package). Call .Parse() afterwards to parse all Go files (including CGo
 // processing, if necessary).
-func (p *Program) Load(importPath string) error {
-	if p.Packages == nil {
-		p.Packages = make(map[string]*Package)
+func Load(config *compileopts.Config, inputPkgs []string, clangHeaders string, typeChecker types.Config) (*Program, error) {
+	goroot, err := GetCachedGoroot(config)
+	if err != nil {
+		return nil, err
+	}
+	wd, err := os.Getwd()
+	if err != nil {
+		return nil, err
+	}
+	p := &Program{
+		config:       config,
+		clangHeaders: clangHeaders,
+		typeChecker:  typeChecker,
+		goroot:       goroot,
+		workingDir:   wd,
+		Packages:     make(map[string]*Package),
+		fset:         token.NewFileSet(),
 	}
 
-	err := p.loadPackage(importPath)
+	// List the dependencies of this package, in raw JSON format.
+	extraArgs := []string{"-json", "-deps"}
+	if config.TestConfig.CompileTestBinary {
+		extraArgs = append(extraArgs, "-test")
+	}
+	cmd, err := List(config, extraArgs, inputPkgs)
 	if err != nil {
-		return err
+		return nil, err
 	}
-	p.MainPkg = p.sorted[len(p.sorted)-1]
-	if _, ok := p.Packages["runtime"]; !ok {
-		// The runtime package wasn't loaded. Although `go list -deps` seems to
-		// return the full dependency list, there is no way to get those
-		// packages from the go/packages package. Therefore load the runtime
-		// manually and add it to the list of to-be-compiled packages
-		// (duplicates are already filtered).
-		return p.loadPackage("runtime")
+	buf := &bytes.Buffer{}
+	cmd.Stdout = buf
+	cmd.Stderr = os.Stderr
+	err = cmd.Run()
+	if err != nil {
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
+				os.Exit(status.ExitStatus())
+			}
+			os.Exit(1)
+		}
+		return nil, fmt.Errorf("failed to run `go list`: %s", err)
 	}
-	return nil
-}
 
-func (p *Program) loadPackage(importPath string) error {
-	cgoEnabled := "0"
-	if p.Build.CgoEnabled {
-		cgoEnabled = "1"
-	}
-	pkgs, err := packages.Load(&packages.Config{
-		Mode:       packages.NeedName | packages.NeedFiles | packages.NeedImports | packages.NeedDeps,
-		Env:        append(os.Environ(), "GOROOT="+p.Build.GOROOT, "GOOS="+p.Build.GOOS, "GOARCH="+p.Build.GOARCH, "CGO_ENABLED="+cgoEnabled),
-		BuildFlags: []string{"-tags", strings.Join(p.Build.BuildTags, " ")},
-		Tests:      p.Tests,
-	}, importPath)
-	if err != nil {
-		return err
-	}
-	var pkg *packages.Package
-	if p.Tests {
-		// We need the second package. Quoting from the docs:
-		// > For example, when using the go command, loading "fmt" with Tests=true
-		// > returns four packages, with IDs "fmt" (the standard package),
-		// > "fmt [fmt.test]" (the package as compiled for the test),
-		// > "fmt_test" (the test functions from source files in package fmt_test),
-		// > and "fmt.test" (the test binary).
-		pkg = pkgs[1]
-	} else {
-		if len(pkgs) != 1 {
-			return fmt.Errorf("expected exactly one package while importing %s, got %d", importPath, len(pkgs))
+	// Parse the returned json from `go list`.
+	decoder := json.NewDecoder(buf)
+	for {
+		pkg := &Package{
+			program: p,
+			info: types.Info{
+				Types:      make(map[ast.Expr]types.TypeAndValue),
+				Defs:       make(map[*ast.Ident]types.Object),
+				Uses:       make(map[*ast.Ident]types.Object),
+				Implicits:  make(map[ast.Node]types.Object),
+				Scopes:     make(map[ast.Node]*types.Scope),
+				Selections: make(map[*ast.SelectorExpr]*types.Selection),
+			},
 		}
-		pkg = pkgs[0]
-	}
-	var importError *Errors
-	var addPackages func(pkg *packages.Package)
-	addPackages = func(pkg *packages.Package) {
-		if _, ok := p.Packages[pkg.PkgPath]; ok {
-			return
+		err := decoder.Decode(&pkg.PackageJSON)
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return nil, err
 		}
-		pkg2 := p.newPackage(pkg)
-		p.Packages[pkg.PkgPath] = pkg2
-		if len(pkg.Errors) != 0 {
-			if importError != nil {
-				// There was another error reported already. Do not report
-				// errors from multiple packages at once.
-				return
-			}
-			importError = &Errors{
-				Pkg: pkg2,
-			}
-			for _, err := range pkg.Errors {
-				pos := token.Position{}
-				fields := strings.Split(err.Pos, ":")
-				if len(fields) >= 2 {
-					// There is some file/line/column information.
-					if n, err := strconv.Atoi(fields[len(fields)-2]); err == nil {
-						// Format: filename.go:line:colum
-						pos.Filename = strings.Join(fields[:len(fields)-2], ":")
-						pos.Line = n
-						pos.Column, _ = strconv.Atoi(fields[len(fields)-1])
-					} else {
-						// Format: filename.go:line
-						pos.Filename = strings.Join(fields[:len(fields)-1], ":")
-						pos.Line, _ = strconv.Atoi(fields[len(fields)-1])
-					}
-					pos.Filename = p.getOriginalPath(pos.Filename)
+		if pkg.Error != nil {
+			// There was an error while importing (for example, a circular
+			// dependency).
+			pos := token.Position{}
+			fields := strings.Split(pkg.Error.Pos, ":")
+			if len(fields) >= 2 {
+				// There is some file/line/column information.
+				if n, err := strconv.Atoi(fields[len(fields)-2]); err == nil {
+					// Format: filename.go:line:colum
+					pos.Filename = strings.Join(fields[:len(fields)-2], ":")
+					pos.Line = n
+					pos.Column, _ = strconv.Atoi(fields[len(fields)-1])
+				} else {
+					// Format: filename.go:line
+					pos.Filename = strings.Join(fields[:len(fields)-1], ":")
+					pos.Line, _ = strconv.Atoi(fields[len(fields)-1])
 				}
-				importError.Errs = append(importError.Errs, scanner.Error{
-					Pos: pos,
-					Msg: err.Msg,
-				})
+				pos.Filename = p.getOriginalPath(pos.Filename)
 			}
-			return
+			err := scanner.Error{
+				Pos: pos,
+				Msg: pkg.Error.Err,
+			}
+			if len(pkg.Error.ImportStack) != 0 {
+				return nil, Error{
+					ImportStack: pkg.Error.ImportStack,
+					Err:         err,
+				}
+			}
+			return nil, err
 		}
-
-		// Get the list of imports (sorted alphabetically).
-		names := make([]string, 0, len(pkg.Imports))
-		for name := range pkg.Imports {
-			names = append(names, name)
+		if config.TestConfig.CompileTestBinary {
+			// When creating a test binary, `go list` will list two or three
+			// packages used for testing the package. The first is the original
+			// package as if it were built normally, the second is the same
+			// package but with the *_test.go files included. A possible third
+			// may be included for _test packages (such as math_test), used to
+			// test the external API with no access to internal functions.
+			// All packages that are necessary for testing (including the to be
+			// tested package with *_test.go files, but excluding the original
+			// unmodified package) have a suffix added to the import path, for
+			// example the math package has import path "math [math.test]" and
+			// test dependencies such as fmt will have an import path of the
+			// form "fmt [math.test]".
+			// The code below removes this suffix, and if this results in a
+			// duplicate (which happens with the to-be-tested package without
+			// *.test.go files) the previous package is removed from the list of
+			// packages included in this build.
+			// This is necessary because the change in import paths results in
+			// breakage to //go:linkname. Additionally, the duplicated package
+			// slows down the build and so is best removed.
+			if pkg.ForTest != "" && strings.HasSuffix(pkg.ImportPath, " ["+pkg.ForTest+".test]") {
+				newImportPath := pkg.ImportPath[:len(pkg.ImportPath)-len(" ["+pkg.ForTest+".test]")]
+				if _, ok := p.Packages[newImportPath]; ok {
+					// Delete the previous package (that this package overrides).
+					delete(p.Packages, newImportPath)
+					for i, pkg := range p.sorted {
+						if pkg.ImportPath == newImportPath {
+							p.sorted = append(p.sorted[:i], p.sorted[i+1:]...) // remove element from slice
+							break
+						}
+					}
+				}
+				pkg.ImportPath = newImportPath
+			}
 		}
-		sort.Strings(names)
-
-		// Add all the imports.
-		for _, name := range names {
-			addPackages(pkg.Imports[name])
-		}
-
-		p.sorted = append(p.sorted, pkg2)
+		p.sorted = append(p.sorted, pkg)
+		p.Packages[pkg.ImportPath] = pkg
 	}
-	addPackages(pkg)
-	if importError != nil {
-		return *importError
-	}
-	return nil
+
+	return p, nil
 }
 
 // getOriginalPath looks whether this path is in the generated GOROOT and if so,
@@ -168,23 +215,23 @@ func (p *Program) loadPackage(importPath string) error {
 // the input path is returned.
 func (p *Program) getOriginalPath(path string) string {
 	originalPath := path
-	if strings.HasPrefix(path, p.Build.GOROOT+string(filepath.Separator)) {
+	if strings.HasPrefix(path, p.goroot+string(filepath.Separator)) {
 		// If this file is part of the synthetic GOROOT, try to infer the
 		// original path.
-		relpath := path[len(filepath.Join(p.Build.GOROOT, "src"))+1:]
+		relpath := path[len(filepath.Join(p.goroot, "src"))+1:]
 		realgorootPath := filepath.Join(goenv.Get("GOROOT"), "src", relpath)
 		if _, err := os.Stat(realgorootPath); err == nil {
 			originalPath = realgorootPath
 		}
 		maybeInTinyGoRoot := false
-		for prefix := range pathsToOverride(needsSyscallPackage(p.Build.BuildTags)) {
+		for prefix := range pathsToOverride(needsSyscallPackage(p.config.BuildTags())) {
 			if !strings.HasPrefix(relpath, prefix) {
 				continue
 			}
 			maybeInTinyGoRoot = true
 		}
 		if maybeInTinyGoRoot {
-			tinygoPath := filepath.Join(p.TINYGOROOT, "src", relpath)
+			tinygoPath := filepath.Join(goenv.Get("TINYGOROOT"), "src", relpath)
 			if _, err := os.Stat(tinygoPath); err == nil {
 				originalPath = tinygoPath
 			}
@@ -193,28 +240,18 @@ func (p *Program) getOriginalPath(path string) string {
 	return originalPath
 }
 
-// newPackage instantiates a new *Package object with initialized members.
-func (p *Program) newPackage(pkg *packages.Package) *Package {
-	return &Package{
-		Program: p,
-		Package: pkg,
-		Info: types.Info{
-			Types:      make(map[ast.Expr]types.TypeAndValue),
-			Defs:       make(map[*ast.Ident]types.Object),
-			Uses:       make(map[*ast.Ident]types.Object),
-			Implicits:  make(map[ast.Node]types.Object),
-			Scopes:     make(map[ast.Node]*types.Scope),
-			Selections: make(map[*ast.SelectorExpr]*types.Selection),
-		},
-	}
-}
-
 // Sorted returns a list of all packages, sorted in a way that no packages come
 // before the packages they depend upon.
 func (p *Program) Sorted() []*Package {
 	return p.sorted
 }
 
+// MainPkg returns the last package in the Sorted() slice. This is the main
+// package of the program.
+func (p *Program) MainPkg() *Package {
+	return p.sorted[len(p.sorted)-1]
+}
+
 // Parse parses all packages and typechecks them.
 //
 // The returned error may be an Errors error, which contains a list of errors.
@@ -222,22 +259,16 @@ func (p *Program) Sorted() []*Package {
 // Idempotent.
 func (p *Program) Parse() error {
 	// Parse all packages.
-	for _, pkg := range p.Sorted() {
+	// TODO: do this in parallel.
+	for _, pkg := range p.sorted {
 		err := pkg.Parse()
 		if err != nil {
 			return err
 		}
 	}
 
-	if p.Tests {
-		err := p.swapTestMain()
-		if err != nil {
-			return err
-		}
-	}
-
 	// Typecheck all packages.
-	for _, pkg := range p.Sorted() {
+	for _, pkg := range p.sorted {
 		err := pkg.Check()
 		if err != nil {
 			return err
@@ -247,82 +278,6 @@ func (p *Program) Parse() error {
 	return nil
 }
 
-func (p *Program) swapTestMain() error {
-	var tests []string
-
-	isTestFunc := func(f *ast.FuncDecl) bool {
-		// TODO: improve signature check
-		if strings.HasPrefix(f.Name.Name, "Test") && f.Name.Name != "TestMain" {
-			return true
-		}
-		return false
-	}
-	for _, f := range p.MainPkg.Files {
-		for i, d := range f.Decls {
-			switch v := d.(type) {
-			case *ast.FuncDecl:
-				if isTestFunc(v) {
-					tests = append(tests, v.Name.Name)
-				}
-				if v.Name.Name == "main" {
-					// Remove main
-					if len(f.Decls) == 1 {
-						f.Decls = make([]ast.Decl, 0)
-					} else {
-						f.Decls[i] = f.Decls[len(f.Decls)-1]
-						f.Decls = f.Decls[:len(f.Decls)-1]
-					}
-				}
-			}
-		}
-	}
-
-	// TODO: Check if they defined a TestMain and call it instead of testing.TestMain
-	const mainBody = `package main
-
-import (
-	"testing"
-)
-
-func main () {
-	m := &testing.M{
-		Tests: []testing.TestToCall{
-{{range .TestFunctions}}
-			{Name: "{{.}}", Func: {{.}}},
-{{end}}
-		},
-	}
-
-	testing.TestMain(m)
-}
-`
-	tmpl := template.Must(template.New("testmain").Parse(mainBody))
-	b := bytes.Buffer{}
-	tmplData := struct {
-		TestFunctions []string
-	}{
-		TestFunctions: tests,
-	}
-
-	err := tmpl.Execute(&b, tmplData)
-	if err != nil {
-		return err
-	}
-	path := filepath.Join(p.MainPkg.Dir, "$testmain.go")
-
-	if p.fset == nil {
-		p.fset = token.NewFileSet()
-	}
-
-	newMain, err := parser.ParseFile(p.fset, path, b.Bytes(), parser.AllErrors)
-	if err != nil {
-		return err
-	}
-	p.MainPkg.Files = append(p.MainPkg.Files, newMain)
-
-	return nil
-}
-
 // parseFile is a wrapper around parser.ParseFile.
 func (p *Program) parseFile(path string, mode parser.Mode) (*ast.File, error) {
 	if p.fset == nil {
@@ -342,14 +297,13 @@ func (p *Program) parseFile(path string, mode parser.Mode) (*ast.File, error) {
 // Idempotent.
 func (p *Package) Parse() error {
 	if len(p.Files) != 0 {
-		return nil
+		return nil // nothing to do (?)
 	}
 
 	// Load the AST.
-	// TODO: do this in parallel.
-	if p.PkgPath == "unsafe" {
-		// Special case for the unsafe package. Don't even bother loading
-		// the files.
+	if p.ImportPath == "unsafe" {
+		// Special case for the unsafe package, which is defined internally by
+		// the types package.
 		p.Pkg = types.Unsafe
 		return nil
 	}
@@ -369,11 +323,11 @@ func (p *Package) Parse() error {
 // Idempotent.
 func (p *Package) Check() error {
 	if p.Pkg != nil {
-		return nil
+		return nil // already typechecked
 	}
 
 	var typeErrors []error
-	checker := p.TypeChecker
+	checker := p.program.typeChecker // make a copy, because it will be modified
 	checker.Error = func(err error) {
 		typeErrors = append(typeErrors, err)
 	}
@@ -381,7 +335,7 @@ func (p *Package) Check() error {
 	// Do typechecking of the package.
 	checker.Importer = p
 
-	typesPkg, err := checker.Check(p.PkgPath, p.fset, p.Files, &p.Info)
+	typesPkg, err := checker.Check(p.ImportPath, p.program.fset, p.Files, &p.info)
 	if err != nil {
 		if err, ok := err.(Errors); ok {
 			return err
@@ -394,40 +348,46 @@ func (p *Package) Check() error {
 
 // parseFiles parses the loaded list of files and returns this list.
 func (p *Package) parseFiles() ([]*ast.File, error) {
-	// TODO: do this concurrently.
 	var files []*ast.File
 	var fileErrs []error
 
-	var cgoFiles []*ast.File
-	for _, file := range p.GoFiles {
-		f, err := p.parseFile(file, parser.ParseComments)
+	// Parse all files (incuding CgoFiles).
+	parseFile := func(file string) {
+		if !filepath.IsAbs(file) {
+			file = filepath.Join(p.Dir, file)
+		}
+		f, err := p.program.parseFile(file, parser.ParseComments)
 		if err != nil {
 			fileErrs = append(fileErrs, err)
-			continue
-		}
-		if err != nil {
-			fileErrs = append(fileErrs, err)
-			continue
-		}
-		for _, importSpec := range f.Imports {
-			if importSpec.Path.Value == `"C"` {
-				cgoFiles = append(cgoFiles, f)
-			}
+			return
 		}
 		files = append(files, f)
 	}
-	if len(cgoFiles) != 0 {
-		cflags := append(p.CFlags, "-I"+filepath.Dir(p.GoFiles[0]))
-		if p.ClangHeaders != "" {
-			cflags = append(cflags, "-Xclang", "-internal-isystem", "-Xclang", p.ClangHeaders)
+	for _, file := range p.GoFiles {
+		parseFile(file)
+	}
+	for _, file := range p.CgoFiles {
+		parseFile(file)
+	}
+
+	// Do CGo processing.
+	if len(p.CgoFiles) != 0 {
+		var cflags []string
+		cflags = append(cflags, p.program.config.CFlags()...)
+		cflags = append(cflags, "-I"+p.Dir)
+		if p.program.clangHeaders != "" {
+			cflags = append(cflags, "-Xclang", "-internal-isystem", "-Xclang", p.program.clangHeaders)
 		}
-		generated, ldflags, errs := cgo.Process(files, p.Program.Dir, p.fset, cflags)
+		generated, ldflags, errs := cgo.Process(files, p.program.workingDir, p.program.fset, cflags)
 		if errs != nil {
 			fileErrs = append(fileErrs, errs...)
 		}
 		files = append(files, generated)
-		p.LDFlags = append(p.LDFlags, ldflags...)
+		p.program.LDFlags = append(p.program.LDFlags, ldflags...)
 	}
+
+	// Only return an error after CGo processing, so that errors in parsing and
+	// CGo can be reported together.
 	if len(fileErrs) != 0 {
 		return nil, Errors{p, fileErrs}
 	}
@@ -441,8 +401,8 @@ func (p *Package) Import(to string) (*types.Package, error) {
 	if to == "unsafe" {
 		return types.Unsafe, nil
 	}
-	if _, ok := p.Imports[to]; ok {
-		return p.Packages[p.Imports[to].PkgPath].Pkg, nil
+	if imported, ok := p.program.Packages[to]; ok {
+		return imported.Pkg, nil
 	} else {
 		return nil, errors.New("package not imported: " + to)
 	}

loader/ssa.go

@@ -10,8 +10,8 @@ import (
 func (p *Program) LoadSSA() *ssa.Program {
 	prog := ssa.NewProgram(p.fset, ssa.SanityCheckFunctions|ssa.BareInits|ssa.GlobalDebug)
 
-	for _, pkg := range p.Sorted() {
-		prog.CreatePackage(pkg.Pkg, pkg.Files, &pkg.Info, true)
+	for _, pkg := range p.sorted {
+		prog.CreatePackage(pkg.Pkg, pkg.Files, &pkg.info, true)
 	}
 
 	return prog

main.go

@@ -8,6 +8,7 @@ import (
 	"go/scanner"
 	"go/types"
 	"io"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"os/signal"
@@ -28,6 +29,12 @@ import (
 	"go.bug.st/serial"
 )
 
+var (
+	// This variable is set at build time using -ldflags parameters.
+	// See: https://stackoverflow.com/a/11355611
+	gitSha1 string
+)
+
 // commandError is an error type to wrap os/exec.Command errors. This provides
 // some more information regarding what went wrong while running a command.
 type commandError struct {
@@ -58,33 +65,28 @@ func moveFile(src, dst string) error {
 	return os.Remove(src)
 }
 
-// copyFile copies the given file from src to dst. It copies first to a .tmp
-// file which is then moved over a possibly already existing file at the
-// destination.
+// copyFile copies the given file from src to dst. It can copy over
+// a possibly already existing file at the destination.
 func copyFile(src, dst string) error {
-	inf, err := os.Open(src)
+	source, err := os.Open(src)
 	if err != nil {
 		return err
 	}
-	defer inf.Close()
-	outpath := dst + ".tmp"
-	outf, err := os.Create(outpath)
+	defer source.Close()
+
+	st, err := source.Stat()
 	if err != nil {
 		return err
 	}
 
-	_, err = io.Copy(outf, inf)
-	if err != nil {
-		os.Remove(outpath)
-		return err
-	}
-
-	err = outf.Close()
+	destination, err := os.OpenFile(dst, os.O_RDWR|os.O_CREATE|os.O_TRUNC, st.Mode())
 	if err != nil {
 		return err
 	}
+	defer destination.Close()
 
-	return os.Rename(dst+".tmp", dst)
+	_, err = io.Copy(destination, source)
+	return err
 }
 
 // Build compiles and links the given package and writes it to outpath.
@@ -94,10 +96,10 @@ func Build(pkgName, outpath string, options *compileopts.Options) error {
 		return err
 	}
 
-	return builder.Build(pkgName, outpath, config, func(tmppath string) error {
-		if err := os.Rename(tmppath, outpath); err != nil {
+	return builder.Build(pkgName, outpath, config, func(result builder.BuildResult) error {
+		if err := os.Rename(result.Binary, outpath); err != nil {
 			// Moving failed. Do a file copy.
-			inf, err := os.Open(tmppath)
+			inf, err := os.Open(result.Binary)
 			if err != nil {
 				return err
 			}
@@ -123,35 +125,71 @@ func Build(pkgName, outpath string, options *compileopts.Options) error {
 }
 
 // Test runs the tests in the given package.
-func Test(pkgName string, options *compileopts.Options) error {
+func Test(pkgName string, options *compileopts.Options, testCompileOnly bool, outpath string) error {
 	options.TestConfig.CompileTestBinary = true
 	config, err := builder.NewConfig(options)
 	if err != nil {
 		return err
 	}
 
-	// Add test build tag. This is incorrect: `go test` only looks at the
-	// _test.go file suffix but does not add the test build tag in the process.
-	// However, it's a simple fix right now.
-	// For details: https://github.com/golang/go/issues/21360
-	config.Target.BuildTags = append(config.Target.BuildTags, "test")
-
-	return builder.Build(pkgName, ".elf", config, func(tmppath string) error {
-		cmd := exec.Command(tmppath)
-		cmd.Stdout = os.Stdout
-		cmd.Stderr = os.Stderr
-		err := cmd.Run()
-		if err != nil {
-			// Propagate the exit code
-			if err, ok := err.(*exec.ExitError); ok {
-				if status, ok := err.Sys().(syscall.WaitStatus); ok {
-					os.Exit(status.ExitStatus())
-				}
-				os.Exit(1)
+	return builder.Build(pkgName, outpath, config, func(result builder.BuildResult) error {
+		if testCompileOnly || outpath != "" {
+			// Write test binary to the specified file name.
+			if outpath == "" {
+				// No -o path was given, so create one now.
+				// This matches the behavior of go test.
+				outpath = filepath.Base(result.MainDir) + ".test"
+			}
+			copyFile(result.Binary, outpath)
+		}
+		if testCompileOnly {
+			// Do not run the test.
+			return nil
+		}
+		if len(config.Target.Emulator) == 0 {
+			// Run directly.
+			cmd := exec.Command(result.Binary)
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+			cmd.Dir = result.MainDir
+			err := cmd.Run()
+			if err != nil {
+				// Propagate the exit code
+				if err, ok := err.(*exec.ExitError); ok {
+					if status, ok := err.Sys().(syscall.WaitStatus); ok {
+						os.Exit(status.ExitStatus())
+					}
+					os.Exit(1)
+				}
+				return &commandError{"failed to run compiled binary", result.Binary, err}
+			}
+			return nil
+		} else {
+			// Run in an emulator.
+			args := append(config.Target.Emulator[1:], result.Binary)
+			cmd := exec.Command(config.Target.Emulator[0], args...)
+			buf := &bytes.Buffer{}
+			w := io.MultiWriter(os.Stdout, buf)
+			cmd.Stdout = w
+			cmd.Stderr = os.Stderr
+			err := cmd.Run()
+			if err != nil {
+				if err, ok := err.(*exec.ExitError); !ok || !err.Exited() {
+					// Workaround for QEMU which always exits with an error.
+					return &commandError{"failed to run emulator with", result.Binary, err}
+				}
+			}
+			testOutput := string(buf.Bytes())
+			if testOutput == "PASS\n" || strings.HasSuffix(testOutput, "\nPASS\n") {
+				// Test passed.
+				return nil
+			} else {
+				// Test failed, either by ending with the word "FAIL" or with a
+				// panic of some sort.
+				os.Exit(1)
+				return nil // unreachable
 			}
-			return &commandError{"failed to run compiled binary", tmppath, err}
 		}
-		return nil
 	})
 }
 
@@ -193,9 +231,9 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 		return errors.New("unknown flash method: " + flashMethod)
 	}
 
-	return builder.Build(pkgName, fileExt, config, func(tmppath string) error {
+	return builder.Build(pkgName, fileExt, config, func(result builder.BuildResult) error {
 		// do we need port reset to put MCU into bootloader mode?
-		if config.Target.PortReset == "true" {
+		if config.Target.PortReset == "true" && flashMethod != "openocd" {
 			if port == "" {
 				var err error
 				port, err = getDefaultPort()
@@ -206,7 +244,7 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 
 			err := touchSerialPortAt1200bps(port)
 			if err != nil {
-				return &commandError{"failed to reset port", tmppath, err}
+				return &commandError{"failed to reset port", result.Binary, err}
 			}
 			// give the target MCU a chance to restart into bootloader
 			time.Sleep(3 * time.Second)
@@ -218,7 +256,7 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			// Create the command.
 			flashCmd := config.Target.FlashCommand
 			fileToken := "{" + fileExt[1:] + "}"
-			flashCmd = strings.Replace(flashCmd, fileToken, tmppath, -1)
+			flashCmd = strings.Replace(flashCmd, fileToken, result.Binary, -1)
 
 			if port == "" && strings.Contains(flashCmd, "{port}") {
 				var err error
@@ -248,21 +286,21 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			cmd.Dir = goenv.Get("TINYGOROOT")
 			err := cmd.Run()
 			if err != nil {
-				return &commandError{"failed to flash", tmppath, err}
+				return &commandError{"failed to flash", result.Binary, err}
 			}
 			return nil
 		case "msd":
 			switch fileExt {
 			case ".uf2":
-				err := flashUF2UsingMSD(config.Target.FlashVolume, tmppath)
+				err := flashUF2UsingMSD(config.Target.FlashVolume, result.Binary)
 				if err != nil {
-					return &commandError{"failed to flash", tmppath, err}
+					return &commandError{"failed to flash", result.Binary, err}
 				}
 				return nil
 			case ".hex":
-				err := flashHexUsingMSD(config.Target.FlashVolume, tmppath)
+				err := flashHexUsingMSD(config.Target.FlashVolume, result.Binary)
 				if err != nil {
-					return &commandError{"failed to flash", tmppath, err}
+					return &commandError{"failed to flash", result.Binary, err}
 				}
 				return nil
 			default:
@@ -273,13 +311,13 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			if err != nil {
 				return err
 			}
-			args = append(args, "-c", "program "+tmppath+" reset exit")
+			args = append(args, "-c", "program "+filepath.ToSlash(result.Binary)+" reset exit")
 			cmd := exec.Command("openocd", args...)
 			cmd.Stdout = os.Stdout
 			cmd.Stderr = os.Stderr
 			err = cmd.Run()
 			if err != nil {
-				return &commandError{"failed to flash", tmppath, err}
+				return &commandError{"failed to flash", result.Binary, err}
 			}
 			return nil
 		default:
@@ -304,7 +342,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 		return errors.New("gdb not configured in the target specification")
 	}
 
-	return builder.Build(pkgName, "", config, func(tmppath string) error {
+	return builder.Build(pkgName, "", config, func(result builder.BuildResult) error {
 		// Find a good way to run GDB.
 		gdbInterface, openocdInterface := config.Programmer()
 		switch gdbInterface {
@@ -313,13 +351,17 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 				// Assume QEMU as an emulator.
 				if config.Target.Emulator[0] == "mgba" {
 					gdbInterface = "mgba"
-				} else {
+				} else if strings.HasPrefix(config.Target.Emulator[0], "qemu-system-") {
 					gdbInterface = "qemu"
+				} else {
+					gdbInterface = "qemu-user"
 				}
 			} else if openocdInterface != "" && config.Target.OpenOCDTarget != "" {
 				gdbInterface = "openocd"
 			} else if config.Target.JLinkDevice != "" {
 				gdbInterface = "jlink"
+			} else {
+				gdbInterface = "native"
 			}
 		}
 
@@ -367,7 +409,15 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 			gdbCommands = append(gdbCommands, "target remote :1234")
 
 			// Run in an emulator.
-			args := append(config.Target.Emulator[1:], tmppath, "-s", "-S")
+			args := append(config.Target.Emulator[1:], result.Binary, "-s", "-S")
+			daemon = exec.Command(config.Target.Emulator[0], args...)
+			daemon.Stdout = os.Stdout
+			daemon.Stderr = os.Stderr
+		case "qemu-user":
+			gdbCommands = append(gdbCommands, "target remote :1234")
+
+			// Run in an emulator.
+			args := append(config.Target.Emulator[1:], "-g", "1234", result.Binary)
 			daemon = exec.Command(config.Target.Emulator[0], args...)
 			daemon.Stdout = os.Stdout
 			daemon.Stderr = os.Stderr
@@ -375,7 +425,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 			gdbCommands = append(gdbCommands, "target remote :2345")
 
 			// Run in an emulator.
-			args := append(config.Target.Emulator[1:], tmppath, "-g")
+			args := append(config.Target.Emulator[1:], result.Binary, "-g")
 			daemon = exec.Command(config.Target.Emulator[0], args...)
 			daemon.Stdout = os.Stdout
 			daemon.Stderr = os.Stderr
@@ -413,7 +463,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 		// Construct and execute a gdb command.
 		// By default: gdb -ex run <binary>
 		// Exit GDB with Ctrl-D.
-		params := []string{tmppath}
+		params := []string{result.Binary}
 		for _, cmd := range gdbCommands {
 			params = append(params, "-ex", cmd)
 		}
@@ -423,7 +473,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 		cmd.Stderr = os.Stderr
 		err := cmd.Run()
 		if err != nil {
-			return &commandError{"failed to run gdb with", tmppath, err}
+			return &commandError{"failed to run gdb with", result.Binary, err}
 		}
 		return nil
 	})
@@ -439,10 +489,10 @@ func Run(pkgName string, options *compileopts.Options) error {
 		return err
 	}
 
-	return builder.Build(pkgName, ".elf", config, func(tmppath string) error {
+	return builder.Build(pkgName, ".elf", config, func(result builder.BuildResult) error {
 		if len(config.Target.Emulator) == 0 {
 			// Run directly.
-			cmd := exec.Command(tmppath)
+			cmd := exec.Command(result.Binary)
 			cmd.Stdout = os.Stdout
 			cmd.Stderr = os.Stderr
 			err := cmd.Run()
@@ -451,12 +501,12 @@ func Run(pkgName string, options *compileopts.Options) error {
 					// Workaround for QEMU which always exits with an error.
 					return nil
 				}
-				return &commandError{"failed to run compiled binary", tmppath, err}
+				return &commandError{"failed to run compiled binary", result.Binary, err}
 			}
 			return nil
 		} else {
 			// Run in an emulator.
-			args := append(config.Target.Emulator[1:], tmppath)
+			args := append(config.Target.Emulator[1:], result.Binary)
 			cmd := exec.Command(config.Target.Emulator[0], args...)
 			cmd.Stdout = os.Stdout
 			cmd.Stderr = os.Stderr
@@ -466,7 +516,7 @@ func Run(pkgName string, options *compileopts.Options) error {
 					// Workaround for QEMU which always exits with an error.
 					return nil
 				}
-				return &commandError{"failed to run emulator with", tmppath, err}
+				return &commandError{"failed to run emulator with", result.Binary, err}
 			}
 			return nil
 		}
@@ -652,36 +702,6 @@ func getDefaultPort() (port string, err error) {
 	return d[0], nil
 }
 
-// runGoList runs the `go list` command but using the configuration used for
-// TinyGo.
-func runGoList(config *compileopts.Config, flagJSON, flagDeps bool, pkgs []string) error {
-	goroot, err := loader.GetCachedGoroot(config)
-	if err != nil {
-		return err
-	}
-	args := []string{"list"}
-	if flagJSON {
-		args = append(args, "-json")
-	}
-	if flagDeps {
-		args = append(args, "-deps")
-	}
-	if len(config.BuildTags()) != 0 {
-		args = append(args, "-tags", strings.Join(config.BuildTags(), " "))
-	}
-	args = append(args, pkgs...)
-	cgoEnabled := "0"
-	if config.CgoEnabled() {
-		cgoEnabled = "1"
-	}
-	cmd := exec.Command("go", args...)
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	cmd.Env = append(os.Environ(), "GOROOT="+goroot, "GOOS="+config.GOOS(), "GOARCH="+config.GOARCH(), "CGO_ENABLED="+cgoEnabled)
-	cmd.Run()
-	return nil
-}
-
 func usage() {
 	fmt.Fprintln(os.Stderr, "TinyGo is a Go compiler for small places.")
 	fmt.Fprintln(os.Stderr, "version:", goenv.Version)
@@ -755,10 +775,16 @@ func printCompilerError(logln func(...interface{}), err error) {
 			}
 		}
 	case loader.Errors:
-		logln("#", err.Pkg.PkgPath)
+		logln("#", err.Pkg.ImportPath)
 		for _, err := range err.Errs {
 			printCompilerError(logln, err)
 		}
+	case loader.Error:
+		logln(err.Err.Error())
+		logln("package", err.ImportStack[0])
+		for _, pkgPath := range err.ImportStack[1:] {
+			logln("\timports", pkgPath)
+		}
 	case *builder.MultiError:
 		for _, err := range err.Errs {
 			printCompilerError(logln, err)
@@ -785,7 +811,6 @@ func main() {
 	}
 	command := os.Args[1]
 
-	outpath := flag.String("o", "", "output filename")
 	opt := flag.String("opt", "z", "optimization level: 0, 1, 2, s, z")
 	gc := flag.String("gc", "", "garbage collector to use (none, leaking, extalloc, conservative)")
 	panicStrategy := flag.String("panic", "print", "panic strategy (print, trap)")
@@ -803,14 +828,22 @@ func main() {
 	programmer := flag.String("programmer", "", "which hardware programmer to use")
 	cFlags := flag.String("cflags", "", "additional cflags for compiler")
 	ldFlags := flag.String("ldflags", "", "additional ldflags for linker")
-	wasmAbi := flag.String("wasm-abi", "js", "WebAssembly ABI conventions: js (no i64 params) or generic")
+	wasmAbi := flag.String("wasm-abi", "", "WebAssembly ABI conventions: js (no i64 params) or generic")
 	heapSize := flag.String("heap-size", "1M", "default heap size in bytes (only supported by WebAssembly)")
 
 	var flagJSON, flagDeps *bool
-	if command == "list" {
+	if command == "help" || command == "list" {
 		flagJSON = flag.Bool("json", false, "print data in JSON format")
 		flagDeps = flag.Bool("deps", false, "")
 	}
+	var outpath string
+	if command == "help" || command == "build" || command == "build-library" || command == "test" {
+		flag.StringVar(&outpath, "o", "", "output filename")
+	}
+	var testCompileOnlyFlag *bool
+	if command == "help" || command == "test" {
+		testCompileOnlyFlag = flag.Bool("c", false, "compile the test binary but do not run it")
+	}
 
 	// Early command processing, before commands are interpreted by the Go flag
 	// library.
@@ -868,7 +901,7 @@ func main() {
 
 	switch command {
 	case "build":
-		if *outpath == "" {
+		if outpath == "" {
 			fmt.Fprintln(os.Stderr, "No output filename supplied (-o).")
 			usage()
 			os.Exit(1)
@@ -881,15 +914,15 @@ func main() {
 			usage()
 			os.Exit(1)
 		}
-		if options.Target == "" && filepath.Ext(*outpath) == ".wasm" {
+		if options.Target == "" && filepath.Ext(outpath) == ".wasm" {
 			options.Target = "wasm"
 		}
 
-		err := Build(pkgName, *outpath, options)
+		err := Build(pkgName, outpath, options)
 		handleCompilerError(err)
 	case "build-library":
 		// Note: this command is only meant to be used while making a release!
-		if *outpath == "" {
+		if outpath == "" {
 			fmt.Fprintln(os.Stderr, "No output filename supplied (-o).")
 			usage()
 			os.Exit(1)
@@ -914,13 +947,8 @@ func main() {
 		}
 		path, err := lib.Load(*target)
 		handleCompilerError(err)
-		copyFile(path, *outpath)
+		copyFile(path, outpath)
 	case "flash", "gdb":
-		if *outpath != "" {
-			fmt.Fprintln(os.Stderr, "Output cannot be specified with the flash command.")
-			usage()
-			os.Exit(1)
-		}
 		pkgName := filepath.ToSlash(flag.Arg(0))
 		if command == "flash" {
 			err := Flash(pkgName, *port, options)
@@ -952,8 +980,37 @@ func main() {
 			usage()
 			os.Exit(1)
 		}
-		err := Test(pkgName, options)
+		err := Test(pkgName, options, *testCompileOnlyFlag, outpath)
 		handleCompilerError(err)
+	case "targets":
+		dir := filepath.Join(goenv.Get("TINYGOROOT"), "targets")
+		entries, err := ioutil.ReadDir(dir)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "could not list targets:", err)
+			os.Exit(1)
+			return
+		}
+		for _, entry := range entries {
+			if !entry.Mode().IsRegular() || !strings.HasSuffix(entry.Name(), ".json") {
+				// Only inspect JSON files.
+				continue
+			}
+			path := filepath.Join(dir, entry.Name())
+			spec, err := compileopts.LoadTarget(path)
+			if err != nil {
+				fmt.Fprintln(os.Stderr, "could not list target:", err)
+				os.Exit(1)
+				return
+			}
+			if spec.FlashMethod == "" && spec.FlashCommand == "" && spec.Emulator == nil {
+				// This doesn't look like a regular target file, but rather like
+				// a parent target (such as targets/cortex-m.json).
+				continue
+			}
+			name := entry.Name()
+			name = name[:len(name)-5]
+			fmt.Println(name)
+		}
 	case "info":
 		if flag.NArg() == 1 {
 			options.Target = flag.Arg(0)
@@ -973,12 +1030,18 @@ func main() {
 			fmt.Fprintln(os.Stderr, err)
 			os.Exit(1)
 		}
+		cachedGOROOT, err := loader.GetCachedGoroot(config)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
 		fmt.Printf("LLVM triple:       %s\n", config.Triple())
 		fmt.Printf("GOOS:              %s\n", config.GOOS())
 		fmt.Printf("GOARCH:            %s\n", config.GOARCH())
 		fmt.Printf("build tags:        %s\n", strings.Join(config.BuildTags(), " "))
 		fmt.Printf("garbage collector: %s\n", config.GC())
 		fmt.Printf("scheduler:         %s\n", config.Scheduler())
+		fmt.Printf("cached GOROOT:     %s\n", cachedGOROOT)
 	case "list":
 		config, err := builder.NewConfig(options)
 		if err != nil {
@@ -986,11 +1049,31 @@ func main() {
 			usage()
 			os.Exit(1)
 		}
-		err = runGoList(config, *flagJSON, *flagDeps, flag.Args())
+		var extraArgs []string
+		if *flagJSON {
+			extraArgs = append(extraArgs, "-json")
+		}
+		if *flagDeps {
+			extraArgs = append(extraArgs, "-deps")
+		}
+		cmd, err := loader.List(config, extraArgs, flag.Args())
 		if err != nil {
 			fmt.Fprintln(os.Stderr, "failed to run `go list`:", err)
 			os.Exit(1)
 		}
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		err = cmd.Run()
+		if err != nil {
+			if exitErr, ok := err.(*exec.ExitError); ok {
+				if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
+					os.Exit(status.ExitStatus())
+				}
+				os.Exit(1)
+			}
+			fmt.Fprintln(os.Stderr, "failed to run `go list`:", err)
+			os.Exit(1)
+		}
 	case "clean":
 		// remove cache directory
 		err := os.RemoveAll(goenv.Get("GOCACHE"))
@@ -1005,7 +1088,11 @@ func main() {
 		if s, err := goenv.GorootVersionString(goenv.Get("GOROOT")); err == nil {
 			goversion = s
 		}
-		fmt.Printf("tinygo version %s %s/%s (using go version %s and LLVM version %s)\n", goenv.Version, runtime.GOOS, runtime.GOARCH, goversion, llvm.Version)
+		version := goenv.Version
+		if strings.HasSuffix(goenv.Version, "-dev") && gitSha1 != "" {
+			version += "-" + gitSha1
+		}
+		fmt.Printf("tinygo version %s %s/%s (using go version %s and LLVM version %s)\n", version, runtime.GOOS, runtime.GOARCH, goversion, llvm.Version)
 	case "env":
 		if flag.NArg() == 0 {
 			// Show all environment variables.

main_test.go

@@ -78,6 +78,9 @@ func TestCompiler(t *testing.T) {
 	}
 
 	if runtime.GOOS == "linux" {
+		t.Run("X86Linux", func(t *testing.T) {
+			runPlatTests("i386--linux-gnu", matches, t)
+		})
 		t.Run("ARMLinux", func(t *testing.T) {
 			runPlatTests("arm--linux-gnueabihf", matches, t)
 		})
@@ -98,6 +101,10 @@ func TestCompiler(t *testing.T) {
 				runPlatTests("wasm", matches, t)
 			})
 		}
+
+		t.Run("WASI", func(t *testing.T) {
+			runPlatTests("wasi", matches, t)
+		})
 	}
 }
 
@@ -109,7 +116,6 @@ func runPlatTests(target string, matches []string, t *testing.T) {
 
 		t.Run(filepath.Base(path), func(t *testing.T) {
 			t.Parallel()
-
 			runTest(path, target, t)
 		})
 	}
@@ -157,10 +163,11 @@ func runTest(path, target string, t *testing.T) {
 		PrintIR:    false,
 		DumpSSA:    false,
 		VerifyIR:   true,
-		Debug:      false,
+		Debug:      true,
 		PrintSizes: "",
-		WasmAbi:    "js",
+		WasmAbi:    "",
 	}
+
 	binary := filepath.Join(tmpdir, "test")
 	err = runBuild("./"+path, binary, config)
 	if err != nil {
@@ -181,10 +188,11 @@ func runTest(path, target string, t *testing.T) {
 			t.Fatal("failed to load target spec:", err)
 		}
 		if len(spec.Emulator) == 0 {
-			t.Fatal("no emulator available for target:", target)
+			cmd = exec.Command(binary)
+		} else {
+			args := append(spec.Emulator[1:], binary)
+			cmd = exec.Command(spec.Emulator[0], args...)
 		}
-		args := append(spec.Emulator[1:], binary)
-		cmd = exec.Command(spec.Emulator[0], args...)
 	}
 	stdout := &bytes.Buffer{}
 	cmd.Stdout = stdout

src/device/arm/arm.go

@@ -76,32 +76,8 @@ const (
 	SCS_BASE  = 0xE000E000
 	SYST_BASE = SCS_BASE + 0x0010
 	NVIC_BASE = SCS_BASE + 0x0100
-	SCB_BASE  = SCS_BASE + 0x0D00
 )
 
-const (
-	SCB_AIRCR_VECTKEY_Pos     = 16
-	SCB_AIRCR_SYSRESETREQ_Pos = 2
-	SCB_AIRCR_SYSRESETREQ_Msk = 1 << SCB_AIRCR_SYSRESETREQ_Pos
-)
-
-// System Control Block (SCB)
-//
-// SCB_Type provides the definitions for the System Control Block Registers.
-type SCB_Type struct {
-	CPUID volatile.Register32    // CPUID Base Register
-	ICSR  volatile.Register32    // Interrupt Control and State Register
-	VTOR  volatile.Register32    // Vector Table Offset Register
-	AIRCR volatile.Register32    // Application Interrupt and Reset Control Register
-	SCR   volatile.Register32    // System Control Register
-	CCR   volatile.Register32    // Configuration Control Register
-	_     volatile.Register32    // RESERVED1;
-	SHP   [2]volatile.Register32 // System Handlers Priority Registers. [0] is RESERVED
-	SHCSR volatile.Register32    // System Handler Control and State Register
-}
-
-var SCB = (*SCB_Type)(unsafe.Pointer(uintptr(SCB_BASE)))
-
 // Nested Vectored Interrupt Controller (NVIC).
 //
 // Source:
@@ -213,17 +189,6 @@ func EnableInterrupts(mask uintptr) {
 	})
 }
 
-// SystemReset performs a hard system reset.
-func SystemReset() {
-	// SCB->AIRCR  = ((0x5FA << SCB_AIRCR_VECTKEY_Pos)      |
-	//              SCB_AIRCR_SYSRESETREQ_Msk);
-	SCB.AIRCR.Set((0x5FA << SCB_AIRCR_VECTKEY_Pos) | SCB_AIRCR_SYSRESETREQ_Msk)
-
-	for {
-		Asm("wfi")
-	}
-}
-
 // Set up the system timer to generate periodic tick events.
 // This will cause SysTick_Handler to fire once per tick.
 // The cyclecount parameter is a counter value which can range from 0 to

src/device/arm/cortexm.s

@@ -1,9 +1,11 @@
 .syntax unified
+.cfi_sections .debug_frame
 
 .section .text.HardFault_Handler
 .global  HardFault_Handler
 .type    HardFault_Handler, %function
 HardFault_Handler:
+    .cfi_startproc
     // Put the old stack pointer in the first argument, for easy debugging. This
     // is especially useful on Cortex-M0, which supports far fewer debug
     // facilities.
@@ -19,6 +21,7 @@ HardFault_Handler:
 
     // Continue handling this error in Go.
     bl handleHardFault
+    .cfi_endproc
 .size HardFault_Handler, .-HardFault_Handler
 
 // This is a convenience function for semihosting support.
@@ -27,5 +30,8 @@ HardFault_Handler:
 .global  SemihostingCall
 .type    SemihostingCall, %function
 SemihostingCall:
+    .cfi_startproc
     bkpt 0xab
     bx   lr
+    .cfi_endproc
+.size SemihostingCall, .-SemihostingCall

src/device/arm/scb.go

@@ -0,0 +1,431 @@
+// Hand created file. DO NOT DELETE.
+// Cortex-M System Control Block-related definitions.
+
+// +build cortexm
+
+package arm
+
+import (
+	"runtime/volatile"
+	"unsafe"
+)
+
+const SCB_BASE = SCS_BASE + 0x0D00
+
+// System Control Block (SCB)
+//
+// SCB_Type provides the definitions for the System Control Block Registers.
+type SCB_Type struct {
+	CPUID volatile.Register32 // 0xD00: CPUID Base Register
+	ICSR  volatile.Register32 // 0xD04: Interrupt Control and State Register
+	VTOR  volatile.Register32 // 0xD08: Vector Table Offset Register
+	AIRCR volatile.Register32 // 0xD0C: Application Interrupt and Reset Control Register
+	SCR   volatile.Register32 // 0xD10: System Control Register
+	CCR   volatile.Register32 // 0xD14: Configuration and Control Register
+	SHPR1 volatile.Register32 // 0xD18: System Handler Priority Register 1 (Cortex-M3/M33/M4/M7 only)
+	SHPR2 volatile.Register32 // 0xD1C: System Handler Priority Register 2
+	SHPR3 volatile.Register32 // 0xD20: System Handler Priority Register 3
+	// the following are only applicable for Cortex-M3/M33/M4/M7
+	SHCSR volatile.Register32 // 0xD24: System Handler Control and State Register
+	CFSR  volatile.Register32 // 0xD28: Configurable Fault Status Register
+	HFSR  volatile.Register32 // 0xD2C: HardFault Status Register
+	DFSR  volatile.Register32 // 0xD30: Debug Fault Status Register
+	MMFAR volatile.Register32 // 0xD34: MemManage Fault Address Register
+	BFAR  volatile.Register32 // 0xD38: BusFault Address Register
+}
+
+var SCB = (*SCB_Type)(unsafe.Pointer(uintptr(SCB_BASE)))
+
+// SystemReset performs a hard system reset.
+func SystemReset() {
+	SCB.AIRCR.Set((0x5FA << SCB_AIRCR_VECTKEY_Pos) | SCB_AIRCR_SYSRESETREQ_Msk)
+	for {
+		Asm("wfi")
+	}
+}
+
+const (
+	// CPUID: CPUID Base Register
+	SCB_CPUID_REVISION_Pos     = 0x0        // Position of REVISION field.
+	SCB_CPUID_REVISION_Msk     = 0xf        // Bit mask of REVISION field.
+	SCB_CPUID_PARTNO_Pos       = 0x4        // Position of PARTNO field.
+	SCB_CPUID_PARTNO_Msk       = 0xfff0     // Bit mask of PARTNO field.
+	SCB_CPUID_ARCHITECTURE_Pos = 0x10       // Position of ARCHITECTURE field.
+	SCB_CPUID_ARCHITECTURE_Msk = 0xf0000    // Bit mask of ARCHITECTURE field.
+	SCB_CPUID_VARIANT_Pos      = 0x14       // Position of VARIANT field.
+	SCB_CPUID_VARIANT_Msk      = 0xf00000   // Bit mask of VARIANT field.
+	SCB_CPUID_IMPLEMENTER_Pos  = 0x18       // Position of IMPLEMENTER field.
+	SCB_CPUID_IMPLEMENTER_Msk  = 0xff000000 // Bit mask of IMPLEMENTER field.
+
+	// ICSR: Interrupt Control and State Register
+	SCB_ICSR_VECTACTIVE_Pos          = 0x0        // Position of VECTACTIVE field.
+	SCB_ICSR_VECTACTIVE_Msk          = 0x1ff      // Bit mask of VECTACTIVE field.
+	SCB_ICSR_RETTOBASE_Pos           = 0xb        // Position of RETTOBASE field.
+	SCB_ICSR_RETTOBASE_Msk           = 0x800      // Bit mask of RETTOBASE field.
+	SCB_ICSR_RETTOBASE               = 0x800      // Bit RETTOBASE.
+	SCB_ICSR_RETTOBASE_RETTOBASE_0   = 0x0        // there are preempted active exceptions to execute
+	SCB_ICSR_RETTOBASE_RETTOBASE_1   = 0x1        // there are no active exceptions, or the currently-executing exception is the only active exception
+	SCB_ICSR_VECTPENDING_Pos         = 0xc        // Position of VECTPENDING field.
+	SCB_ICSR_VECTPENDING_Msk         = 0x1ff000   // Bit mask of VECTPENDING field.
+	SCB_ICSR_ISRPENDING_Pos          = 0x16       // Position of ISRPENDING field.
+	SCB_ICSR_ISRPENDING_Msk          = 0x400000   // Bit mask of ISRPENDING field.
+	SCB_ICSR_ISRPENDING              = 0x400000   // Bit ISRPENDING.
+	SCB_ICSR_ISRPENDING_ISRPENDING_0 = 0x0        // No external interrupt pending.
+	SCB_ICSR_ISRPENDING_ISRPENDING_1 = 0x1        // External interrupt pending.
+	SCB_ICSR_PENDSTCLR_Pos           = 0x19       // Position of PENDSTCLR field.
+	SCB_ICSR_PENDSTCLR_Msk           = 0x2000000  // Bit mask of PENDSTCLR field.
+	SCB_ICSR_PENDSTCLR               = 0x2000000  // Bit PENDSTCLR.
+	SCB_ICSR_PENDSTCLR_PENDSTCLR_0   = 0x0        // no effect
+	SCB_ICSR_PENDSTCLR_PENDSTCLR_1   = 0x1        // removes the pending state from the SysTick exception
+	SCB_ICSR_PENDSTSET_Pos           = 0x1a       // Position of PENDSTSET field.
+	SCB_ICSR_PENDSTSET_Msk           = 0x4000000  // Bit mask of PENDSTSET field.
+	SCB_ICSR_PENDSTSET               = 0x4000000  // Bit PENDSTSET.
+	SCB_ICSR_PENDSTSET_PENDSTSET_0   = 0x0        // write: no effect; read: SysTick exception is not pending
+	SCB_ICSR_PENDSTSET_PENDSTSET_1   = 0x1        // write: changes SysTick exception state to pending; read: SysTick exception is pending
+	SCB_ICSR_PENDSVCLR_Pos           = 0x1b       // Position of PENDSVCLR field.
+	SCB_ICSR_PENDSVCLR_Msk           = 0x8000000  // Bit mask of PENDSVCLR field.
+	SCB_ICSR_PENDSVCLR               = 0x8000000  // Bit PENDSVCLR.
+	SCB_ICSR_PENDSVCLR_PENDSVCLR_0   = 0x0        // no effect
+	SCB_ICSR_PENDSVCLR_PENDSVCLR_1   = 0x1        // removes the pending state from the PendSV exception
+	SCB_ICSR_PENDSVSET_Pos           = 0x1c       // Position of PENDSVSET field.
+	SCB_ICSR_PENDSVSET_Msk           = 0x10000000 // Bit mask of PENDSVSET field.
+	SCB_ICSR_PENDSVSET               = 0x10000000 // Bit PENDSVSET.
+	SCB_ICSR_PENDSVSET_PENDSVSET_0   = 0x0        // write: no effect; read: PendSV exception is not pending
+	SCB_ICSR_PENDSVSET_PENDSVSET_1   = 0x1        // write: changes PendSV exception state to pending; read: PendSV exception is pending
+	SCB_ICSR_NMIPENDSET_Pos          = 0x1f       // Position of NMIPENDSET field.
+	SCB_ICSR_NMIPENDSET_Msk          = 0x80000000 // Bit mask of NMIPENDSET field.
+	SCB_ICSR_NMIPENDSET              = 0x80000000 // Bit NMIPENDSET.
+	SCB_ICSR_NMIPENDSET_NMIPENDSET_0 = 0x0        // write: no effect; read: NMI exception is not pending
+	SCB_ICSR_NMIPENDSET_NMIPENDSET_1 = 0x1        // write: changes NMI exception state to pending; read: NMI exception is pending
+
+	// VTOR: Vector Table Offset Register
+	SCB_VTOR_TBLOFF_Pos = 0x7        // Position of TBLOFF field.
+	SCB_VTOR_TBLOFF_Msk = 0xffffff80 // Bit mask of TBLOFF field.
+
+	// AIRCR: Application Interrupt and Reset Control Register
+	SCB_AIRCR_VECTRESET_Pos                 = 0x0        // Position of VECTRESET field.
+	SCB_AIRCR_VECTRESET_Msk                 = 0x1        // Bit mask of VECTRESET field.
+	SCB_AIRCR_VECTRESET                     = 0x1        // Bit VECTRESET.
+	SCB_AIRCR_VECTRESET_VECTRESET_0         = 0x0        // No change
+	SCB_AIRCR_VECTRESET_VECTRESET_1         = 0x1        // Causes a local system reset
+	SCB_AIRCR_VECTCLRACTIVE_Pos             = 0x1        // Position of VECTCLRACTIVE field.
+	SCB_AIRCR_VECTCLRACTIVE_Msk             = 0x2        // Bit mask of VECTCLRACTIVE field.
+	SCB_AIRCR_VECTCLRACTIVE                 = 0x2        // Bit VECTCLRACTIVE.
+	SCB_AIRCR_VECTCLRACTIVE_VECTCLRACTIVE_0 = 0x0        // No change
+	SCB_AIRCR_VECTCLRACTIVE_VECTCLRACTIVE_1 = 0x1        // Clears all active state information for fixed and configurable exceptions
+	SCB_AIRCR_SYSRESETREQ_Pos               = 0x2        // Position of SYSRESETREQ field.
+	SCB_AIRCR_SYSRESETREQ_Msk               = 0x4        // Bit mask of SYSRESETREQ field.
+	SCB_AIRCR_SYSRESETREQ                   = 0x4        // Bit SYSRESETREQ.
+	SCB_AIRCR_SYSRESETREQ_SYSRESETREQ_0     = 0x0        // no system reset request
+	SCB_AIRCR_SYSRESETREQ_SYSRESETREQ_1     = 0x1        // asserts a signal to the outer system that requests a reset
+	SCB_AIRCR_PRIGROUP_Pos                  = 0x8        // Position of PRIGROUP field.
+	SCB_AIRCR_PRIGROUP_Msk                  = 0x700      // Bit mask of PRIGROUP field.
+	SCB_AIRCR_ENDIANNESS_Pos                = 0xf        // Position of ENDIANNESS field.
+	SCB_AIRCR_ENDIANNESS_Msk                = 0x8000     // Bit mask of ENDIANNESS field.
+	SCB_AIRCR_ENDIANNESS                    = 0x8000     // Bit ENDIANNESS.
+	SCB_AIRCR_ENDIANNESS_ENDIANNESS_0       = 0x0        // Little-endian
+	SCB_AIRCR_ENDIANNESS_ENDIANNESS_1       = 0x1        // Big-endian
+	SCB_AIRCR_VECTKEY_Pos                   = 0x10       // Position of VECTKEY field.
+	SCB_AIRCR_VECTKEY_Msk                   = 0xffff0000 // Bit mask of VECTKEY field.
+
+	// SCR: System Control Register
+	SCB_SCR_SLEEPONEXIT_Pos           = 0x1  // Position of SLEEPONEXIT field.
+	SCB_SCR_SLEEPONEXIT_Msk           = 0x2  // Bit mask of SLEEPONEXIT field.
+	SCB_SCR_SLEEPONEXIT               = 0x2  // Bit SLEEPONEXIT.
+	SCB_SCR_SLEEPONEXIT_SLEEPONEXIT_0 = 0x0  // o not sleep when returning to Thread mode
+	SCB_SCR_SLEEPONEXIT_SLEEPONEXIT_1 = 0x1  // enter sleep, or deep sleep, on return from an ISR
+	SCB_SCR_SLEEPDEEP_Pos             = 0x2  // Position of SLEEPDEEP field.
+	SCB_SCR_SLEEPDEEP_Msk             = 0x4  // Bit mask of SLEEPDEEP field.
+	SCB_SCR_SLEEPDEEP                 = 0x4  // Bit SLEEPDEEP.
+	SCB_SCR_SLEEPDEEP_SLEEPDEEP_0     = 0x0  // sleep
+	SCB_SCR_SLEEPDEEP_SLEEPDEEP_1     = 0x1  // deep sleep
+	SCB_SCR_SEVONPEND_Pos             = 0x4  // Position of SEVONPEND field.
+	SCB_SCR_SEVONPEND_Msk             = 0x10 // Bit mask of SEVONPEND field.
+	SCB_SCR_SEVONPEND                 = 0x10 // Bit SEVONPEND.
+	SCB_SCR_SEVONPEND_SEVONPEND_0     = 0x0  // only enabled interrupts or events can wakeup the processor, disabled interrupts are excluded
+	SCB_SCR_SEVONPEND_SEVONPEND_1     = 0x1  // enabled events and all interrupts, including disabled interrupts, can wakeup the processor
+
+	// CCR: Configuration and Control Register
+	SCB_CCR_NONBASETHRDENA_Pos              = 0x0     // Position of NONBASETHRDENA field.
+	SCB_CCR_NONBASETHRDENA_Msk              = 0x1     // Bit mask of NONBASETHRDENA field.
+	SCB_CCR_NONBASETHRDENA                  = 0x1     // Bit NONBASETHRDENA.
+	SCB_CCR_NONBASETHRDENA_NONBASETHRDENA_0 = 0x0     // processor can enter Thread mode only when no exception is active
+	SCB_CCR_NONBASETHRDENA_NONBASETHRDENA_1 = 0x1     // processor can enter Thread mode from any level under the control of an EXC_RETURN value
+	SCB_CCR_USERSETMPEND_Pos                = 0x1     // Position of USERSETMPEND field.
+	SCB_CCR_USERSETMPEND_Msk                = 0x2     // Bit mask of USERSETMPEND field.
+	SCB_CCR_USERSETMPEND                    = 0x2     // Bit USERSETMPEND.
+	SCB_CCR_USERSETMPEND_USERSETMPEND_0     = 0x0     // disable
+	SCB_CCR_USERSETMPEND_USERSETMPEND_1     = 0x1     // enable
+	SCB_CCR_UNALIGN_TRP_Pos                 = 0x3     // Position of UNALIGN_TRP field.
+	SCB_CCR_UNALIGN_TRP_Msk                 = 0x8     // Bit mask of UNALIGN_TRP field.
+	SCB_CCR_UNALIGN_TRP                     = 0x8     // Bit UNALIGN_TRP.
+	SCB_CCR_UNALIGN_TRP_UNALIGN_TRP_0       = 0x0     // do not trap unaligned halfword and word accesses
+	SCB_CCR_UNALIGN_TRP_UNALIGN_TRP_1       = 0x1     // trap unaligned halfword and word accesses
+	SCB_CCR_DIV_0_TRP_Pos                   = 0x4     // Position of DIV_0_TRP field.
+	SCB_CCR_DIV_0_TRP_Msk                   = 0x10    // Bit mask of DIV_0_TRP field.
+	SCB_CCR_DIV_0_TRP                       = 0x10    // Bit DIV_0_TRP.
+	SCB_CCR_DIV_0_TRP_DIV_0_TRP_0           = 0x0     // do not trap divide by 0
+	SCB_CCR_DIV_0_TRP_DIV_0_TRP_1           = 0x1     // trap divide by 0
+	SCB_CCR_BFHFNMIGN_Pos                   = 0x8     // Position of BFHFNMIGN field.
+	SCB_CCR_BFHFNMIGN_Msk                   = 0x100   // Bit mask of BFHFNMIGN field.
+	SCB_CCR_BFHFNMIGN                       = 0x100   // Bit BFHFNMIGN.
+	SCB_CCR_BFHFNMIGN_BFHFNMIGN_0           = 0x0     // data bus faults caused by load and store instructions cause a lock-up
+	SCB_CCR_BFHFNMIGN_BFHFNMIGN_1           = 0x1     // handlers running at priority -1 and -2 ignore data bus faults caused by load and store instructions
+	SCB_CCR_STKALIGN_Pos                    = 0x9     // Position of STKALIGN field.
+	SCB_CCR_STKALIGN_Msk                    = 0x200   // Bit mask of STKALIGN field.
+	SCB_CCR_STKALIGN                        = 0x200   // Bit STKALIGN.
+	SCB_CCR_STKALIGN_STKALIGN_0             = 0x0     // 4-byte aligned
+	SCB_CCR_STKALIGN_STKALIGN_1             = 0x1     // 8-byte aligned
+	SCB_CCR_DC_Pos                          = 0x10    // Position of DC field.
+	SCB_CCR_DC_Msk                          = 0x10000 // Bit mask of DC field.
+	SCB_CCR_DC                              = 0x10000 // Bit DC.
+	SCB_CCR_DC_DC_0                         = 0x0     // L1 data cache disabled
+	SCB_CCR_DC_DC_1                         = 0x1     // L1 data cache enabled
+	SCB_CCR_IC_Pos                          = 0x11    // Position of IC field.
+	SCB_CCR_IC_Msk                          = 0x20000 // Bit mask of IC field.
+	SCB_CCR_IC                              = 0x20000 // Bit IC.
+	SCB_CCR_IC_IC_0                         = 0x0     // L1 instruction cache disabled
+	SCB_CCR_IC_IC_1                         = 0x1     // L1 instruction cache enabled
+	SCB_CCR_BP_Pos                          = 0x12    // Position of BP field.
+	SCB_CCR_BP_Msk                          = 0x40000 // Bit mask of BP field.
+	SCB_CCR_BP                              = 0x40000 // Bit BP.
+
+	// SHPR1: System Handler Priority Register 1
+	SCB_SHPR1_PRI_4_Pos = 0x0      // Position of PRI_4 field.
+	SCB_SHPR1_PRI_4_Msk = 0xff     // Bit mask of PRI_4 field.
+	SCB_SHPR1_PRI_5_Pos = 0x8      // Position of PRI_5 field.
+	SCB_SHPR1_PRI_5_Msk = 0xff00   // Bit mask of PRI_5 field.
+	SCB_SHPR1_PRI_6_Pos = 0x10     // Position of PRI_6 field.
+	SCB_SHPR1_PRI_6_Msk = 0xff0000 // Bit mask of PRI_6 field.
+
+	// SHPR2: System Handler Priority Register 2
+	SCB_SHPR2_PRI_11_Pos = 0x18       // Position of PRI_11 field.
+	SCB_SHPR2_PRI_11_Msk = 0xff000000 // Bit mask of PRI_11 field.
+
+	// SHPR3: System Handler Priority Register 3
+	SCB_SHPR3_PRI_14_Pos = 0x10       // Position of PRI_14 field.
+	SCB_SHPR3_PRI_14_Msk = 0xff0000   // Bit mask of PRI_14 field.
+	SCB_SHPR3_PRI_15_Pos = 0x18       // Position of PRI_15 field.
+	SCB_SHPR3_PRI_15_Msk = 0xff000000 // Bit mask of PRI_15 field.
+
+	// SHCSR: System Handler Control and State Register
+	SCB_SHCSR_MEMFAULTACT_Pos                 = 0x0     // Position of MEMFAULTACT field.
+	SCB_SHCSR_MEMFAULTACT_Msk                 = 0x1     // Bit mask of MEMFAULTACT field.
+	SCB_SHCSR_MEMFAULTACT                     = 0x1     // Bit MEMFAULTACT.
+	SCB_SHCSR_MEMFAULTACT_MEMFAULTACT_0       = 0x0     // exception is not active
+	SCB_SHCSR_MEMFAULTACT_MEMFAULTACT_1       = 0x1     // exception is active
+	SCB_SHCSR_BUSFAULTACT_Pos                 = 0x1     // Position of BUSFAULTACT field.
+	SCB_SHCSR_BUSFAULTACT_Msk                 = 0x2     // Bit mask of BUSFAULTACT field.
+	SCB_SHCSR_BUSFAULTACT                     = 0x2     // Bit BUSFAULTACT.
+	SCB_SHCSR_BUSFAULTACT_BUSFAULTACT_0       = 0x0     // exception is not active
+	SCB_SHCSR_BUSFAULTACT_BUSFAULTACT_1       = 0x1     // exception is active
+	SCB_SHCSR_USGFAULTACT_Pos                 = 0x3     // Position of USGFAULTACT field.
+	SCB_SHCSR_USGFAULTACT_Msk                 = 0x8     // Bit mask of USGFAULTACT field.
+	SCB_SHCSR_USGFAULTACT                     = 0x8     // Bit USGFAULTACT.
+	SCB_SHCSR_USGFAULTACT_USGFAULTACT_0       = 0x0     // exception is not active
+	SCB_SHCSR_USGFAULTACT_USGFAULTACT_1       = 0x1     // exception is active
+	SCB_SHCSR_SVCALLACT_Pos                   = 0x7     // Position of SVCALLACT field.
+	SCB_SHCSR_SVCALLACT_Msk                   = 0x80    // Bit mask of SVCALLACT field.
+	SCB_SHCSR_SVCALLACT                       = 0x80    // Bit SVCALLACT.
+	SCB_SHCSR_SVCALLACT_SVCALLACT_0           = 0x0     // exception is not active
+	SCB_SHCSR_SVCALLACT_SVCALLACT_1           = 0x1     // exception is active
+	SCB_SHCSR_MONITORACT_Pos                  = 0x8     // Position of MONITORACT field.
+	SCB_SHCSR_MONITORACT_Msk                  = 0x100   // Bit mask of MONITORACT field.
+	SCB_SHCSR_MONITORACT                      = 0x100   // Bit MONITORACT.
+	SCB_SHCSR_MONITORACT_MONITORACT_0         = 0x0     // exception is not active
+	SCB_SHCSR_MONITORACT_MONITORACT_1         = 0x1     // exception is active
+	SCB_SHCSR_PENDSVACT_Pos                   = 0xa     // Position of PENDSVACT field.
+	SCB_SHCSR_PENDSVACT_Msk                   = 0x400   // Bit mask of PENDSVACT field.
+	SCB_SHCSR_PENDSVACT                       = 0x400   // Bit PENDSVACT.
+	SCB_SHCSR_PENDSVACT_PENDSVACT_0           = 0x0     // exception is not active
+	SCB_SHCSR_PENDSVACT_PENDSVACT_1           = 0x1     // exception is active
+	SCB_SHCSR_SYSTICKACT_Pos                  = 0xb     // Position of SYSTICKACT field.
+	SCB_SHCSR_SYSTICKACT_Msk                  = 0x800   // Bit mask of SYSTICKACT field.
+	SCB_SHCSR_SYSTICKACT                      = 0x800   // Bit SYSTICKACT.
+	SCB_SHCSR_SYSTICKACT_SYSTICKACT_0         = 0x0     // exception is not active
+	SCB_SHCSR_SYSTICKACT_SYSTICKACT_1         = 0x1     // exception is active
+	SCB_SHCSR_USGFAULTPENDED_Pos              = 0xc     // Position of USGFAULTPENDED field.
+	SCB_SHCSR_USGFAULTPENDED_Msk              = 0x1000  // Bit mask of USGFAULTPENDED field.
+	SCB_SHCSR_USGFAULTPENDED                  = 0x1000  // Bit USGFAULTPENDED.
+	SCB_SHCSR_USGFAULTPENDED_USGFAULTPENDED_0 = 0x0     // exception is not pending
+	SCB_SHCSR_USGFAULTPENDED_USGFAULTPENDED_1 = 0x1     // exception is pending
+	SCB_SHCSR_MEMFAULTPENDED_Pos              = 0xd     // Position of MEMFAULTPENDED field.
+	SCB_SHCSR_MEMFAULTPENDED_Msk              = 0x2000  // Bit mask of MEMFAULTPENDED field.
+	SCB_SHCSR_MEMFAULTPENDED                  = 0x2000  // Bit MEMFAULTPENDED.
+	SCB_SHCSR_MEMFAULTPENDED_MEMFAULTPENDED_0 = 0x0     // exception is not pending
+	SCB_SHCSR_MEMFAULTPENDED_MEMFAULTPENDED_1 = 0x1     // exception is pending
+	SCB_SHCSR_BUSFAULTPENDED_Pos              = 0xe     // Position of BUSFAULTPENDED field.
+	SCB_SHCSR_BUSFAULTPENDED_Msk              = 0x4000  // Bit mask of BUSFAULTPENDED field.
+	SCB_SHCSR_BUSFAULTPENDED                  = 0x4000  // Bit BUSFAULTPENDED.
+	SCB_SHCSR_BUSFAULTPENDED_BUSFAULTPENDED_0 = 0x0     // exception is not pending
+	SCB_SHCSR_BUSFAULTPENDED_BUSFAULTPENDED_1 = 0x1     // exception is pending
+	SCB_SHCSR_SVCALLPENDED_Pos                = 0xf     // Position of SVCALLPENDED field.
+	SCB_SHCSR_SVCALLPENDED_Msk                = 0x8000  // Bit mask of SVCALLPENDED field.
+	SCB_SHCSR_SVCALLPENDED                    = 0x8000  // Bit SVCALLPENDED.
+	SCB_SHCSR_SVCALLPENDED_SVCALLPENDED_0     = 0x0     // exception is not pending
+	SCB_SHCSR_SVCALLPENDED_SVCALLPENDED_1     = 0x1     // exception is pending
+	SCB_SHCSR_MEMFAULTENA_Pos                 = 0x10    // Position of MEMFAULTENA field.
+	SCB_SHCSR_MEMFAULTENA_Msk                 = 0x10000 // Bit mask of MEMFAULTENA field.
+	SCB_SHCSR_MEMFAULTENA                     = 0x10000 // Bit MEMFAULTENA.
+	SCB_SHCSR_MEMFAULTENA_MEMFAULTENA_0       = 0x0     // disable the exception
+	SCB_SHCSR_MEMFAULTENA_MEMFAULTENA_1       = 0x1     // enable the exception
+	SCB_SHCSR_BUSFAULTENA_Pos                 = 0x11    // Position of BUSFAULTENA field.
+	SCB_SHCSR_BUSFAULTENA_Msk                 = 0x20000 // Bit mask of BUSFAULTENA field.
+	SCB_SHCSR_BUSFAULTENA                     = 0x20000 // Bit BUSFAULTENA.
+	SCB_SHCSR_BUSFAULTENA_BUSFAULTENA_0       = 0x0     // disable the exception
+	SCB_SHCSR_BUSFAULTENA_BUSFAULTENA_1       = 0x1     // enable the exception
+	SCB_SHCSR_USGFAULTENA_Pos                 = 0x12    // Position of USGFAULTENA field.
+	SCB_SHCSR_USGFAULTENA_Msk                 = 0x40000 // Bit mask of USGFAULTENA field.
+	SCB_SHCSR_USGFAULTENA                     = 0x40000 // Bit USGFAULTENA.
+	SCB_SHCSR_USGFAULTENA_USGFAULTENA_0       = 0x0     // disable the exception
+	SCB_SHCSR_USGFAULTENA_USGFAULTENA_1       = 0x1     // enable the exception
+
+	// CFSR: Configurable Fault Status Register
+	SCB_CFSR_IACCVIOL_Pos              = 0x0       // Position of IACCVIOL field.
+	SCB_CFSR_IACCVIOL_Msk              = 0x1       // Bit mask of IACCVIOL field.
+	SCB_CFSR_IACCVIOL                  = 0x1       // Bit IACCVIOL.
+	SCB_CFSR_IACCVIOL_IACCVIOL_0       = 0x0       // no instruction access violation fault
+	SCB_CFSR_IACCVIOL_IACCVIOL_1       = 0x1       // the processor attempted an instruction fetch from a location that does not permit execution
+	SCB_CFSR_DACCVIOL_Pos              = 0x1       // Position of DACCVIOL field.
+	SCB_CFSR_DACCVIOL_Msk              = 0x2       // Bit mask of DACCVIOL field.
+	SCB_CFSR_DACCVIOL                  = 0x2       // Bit DACCVIOL.
+	SCB_CFSR_DACCVIOL_DACCVIOL_0       = 0x0       // no data access violation fault
+	SCB_CFSR_DACCVIOL_DACCVIOL_1       = 0x1       // the processor attempted a load or store at a location that does not permit the operation
+	SCB_CFSR_MUNSTKERR_Pos             = 0x3       // Position of MUNSTKERR field.
+	SCB_CFSR_MUNSTKERR_Msk             = 0x8       // Bit mask of MUNSTKERR field.
+	SCB_CFSR_MUNSTKERR                 = 0x8       // Bit MUNSTKERR.
+	SCB_CFSR_MUNSTKERR_MUNSTKERR_0     = 0x0       // no unstacking fault
+	SCB_CFSR_MUNSTKERR_MUNSTKERR_1     = 0x1       // unstack for an exception return has caused one or more access violations
+	SCB_CFSR_MSTKERR_Pos               = 0x4       // Position of MSTKERR field.
+	SCB_CFSR_MSTKERR_Msk               = 0x10      // Bit mask of MSTKERR field.
+	SCB_CFSR_MSTKERR                   = 0x10      // Bit MSTKERR.
+	SCB_CFSR_MSTKERR_MSTKERR_0         = 0x0       // no stacking fault
+	SCB_CFSR_MSTKERR_MSTKERR_1         = 0x1       // stacking for an exception entry has caused one or more access violations
+	SCB_CFSR_MLSPERR_Pos               = 0x5       // Position of MLSPERR field.
+	SCB_CFSR_MLSPERR_Msk               = 0x20      // Bit mask of MLSPERR field.
+	SCB_CFSR_MLSPERR                   = 0x20      // Bit MLSPERR.
+	SCB_CFSR_MLSPERR_MLSPERR_0         = 0x0       // No MemManage fault occurred during floating-point lazy state preservation
+	SCB_CFSR_MLSPERR_MLSPERR_1         = 0x1       // A MemManage fault occurred during floating-point lazy state preservation
+	SCB_CFSR_MMARVALID_Pos             = 0x7       // Position of MMARVALID field.
+	SCB_CFSR_MMARVALID_Msk             = 0x80      // Bit mask of MMARVALID field.
+	SCB_CFSR_MMARVALID                 = 0x80      // Bit MMARVALID.
+	SCB_CFSR_MMARVALID_MMARVALID_0     = 0x0       // value in MMAR is not a valid fault address
+	SCB_CFSR_MMARVALID_MMARVALID_1     = 0x1       // MMAR holds a valid fault address
+	SCB_CFSR_IBUSERR_Pos               = 0x8       // Position of IBUSERR field.
+	SCB_CFSR_IBUSERR_Msk               = 0x100     // Bit mask of IBUSERR field.
+	SCB_CFSR_IBUSERR                   = 0x100     // Bit IBUSERR.
+	SCB_CFSR_IBUSERR_IBUSERR_0         = 0x0       // no instruction bus error
+	SCB_CFSR_IBUSERR_IBUSERR_1         = 0x1       // instruction bus error
+	SCB_CFSR_PRECISERR_Pos             = 0x9       // Position of PRECISERR field.
+	SCB_CFSR_PRECISERR_Msk             = 0x200     // Bit mask of PRECISERR field.
+	SCB_CFSR_PRECISERR                 = 0x200     // Bit PRECISERR.
+	SCB_CFSR_PRECISERR_PRECISERR_0     = 0x0       // no precise data bus error
+	SCB_CFSR_PRECISERR_PRECISERR_1     = 0x1       // a data bus error has occurred, and the PC value stacked for the exception return points to the instruction that caused the fault
+	SCB_CFSR_IMPRECISERR_Pos           = 0xa       // Position of IMPRECISERR field.
+	SCB_CFSR_IMPRECISERR_Msk           = 0x400     // Bit mask of IMPRECISERR field.
+	SCB_CFSR_IMPRECISERR               = 0x400     // Bit IMPRECISERR.
+	SCB_CFSR_IMPRECISERR_IMPRECISERR_0 = 0x0       // no imprecise data bus error
+	SCB_CFSR_IMPRECISERR_IMPRECISERR_1 = 0x1       // a data bus error has occurred, but the return address in the stack frame is not related to the instruction that caused the error
+	SCB_CFSR_UNSTKERR_Pos              = 0xb       // Position of UNSTKERR field.
+	SCB_CFSR_UNSTKERR_Msk              = 0x800     // Bit mask of UNSTKERR field.
+	SCB_CFSR_UNSTKERR                  = 0x800     // Bit UNSTKERR.
+	SCB_CFSR_UNSTKERR_UNSTKERR_0       = 0x0       // no unstacking fault
+	SCB_CFSR_UNSTKERR_UNSTKERR_1       = 0x1       // unstack for an exception return has caused one or more BusFaults
+	SCB_CFSR_STKERR_Pos                = 0xc       // Position of STKERR field.
+	SCB_CFSR_STKERR_Msk                = 0x1000    // Bit mask of STKERR field.
+	SCB_CFSR_STKERR                    = 0x1000    // Bit STKERR.
+	SCB_CFSR_STKERR_STKERR_0           = 0x0       // no stacking fault
+	SCB_CFSR_STKERR_STKERR_1           = 0x1       // stacking for an exception entry has caused one or more BusFaults
+	SCB_CFSR_LSPERR_Pos                = 0xd       // Position of LSPERR field.
+	SCB_CFSR_LSPERR_Msk                = 0x2000    // Bit mask of LSPERR field.
+	SCB_CFSR_LSPERR                    = 0x2000    // Bit LSPERR.
+	SCB_CFSR_LSPERR_LSPERR_0           = 0x0       // No bus fault occurred during floating-point lazy state preservation
+	SCB_CFSR_LSPERR_LSPERR_1           = 0x1       // A bus fault occurred during floating-point lazy state preservation
+	SCB_CFSR_BFARVALID_Pos             = 0xf       // Position of BFARVALID field.
+	SCB_CFSR_BFARVALID_Msk             = 0x8000    // Bit mask of BFARVALID field.
+	SCB_CFSR_BFARVALID                 = 0x8000    // Bit BFARVALID.
+	SCB_CFSR_BFARVALID_BFARVALID_0     = 0x0       // value in BFAR is not a valid fault address
+	SCB_CFSR_BFARVALID_BFARVALID_1     = 0x1       // BFAR holds a valid fault address
+	SCB_CFSR_UNDEFINSTR_Pos            = 0x10      // Position of UNDEFINSTR field.
+	SCB_CFSR_UNDEFINSTR_Msk            = 0x10000   // Bit mask of UNDEFINSTR field.
+	SCB_CFSR_UNDEFINSTR                = 0x10000   // Bit UNDEFINSTR.
+	SCB_CFSR_UNDEFINSTR_UNDEFINSTR_0   = 0x0       // no undefined instruction UsageFault
+	SCB_CFSR_UNDEFINSTR_UNDEFINSTR_1   = 0x1       // the processor has attempted to execute an undefined instruction
+	SCB_CFSR_INVSTATE_Pos              = 0x11      // Position of INVSTATE field.
+	SCB_CFSR_INVSTATE_Msk              = 0x20000   // Bit mask of INVSTATE field.
+	SCB_CFSR_INVSTATE                  = 0x20000   // Bit INVSTATE.
+	SCB_CFSR_INVSTATE_INVSTATE_0       = 0x0       // no invalid state UsageFault
+	SCB_CFSR_INVSTATE_INVSTATE_1       = 0x1       // the processor has attempted to execute an instruction that makes illegal use of the EPSR
+	SCB_CFSR_INVPC_Pos                 = 0x12      // Position of INVPC field.
+	SCB_CFSR_INVPC_Msk                 = 0x40000   // Bit mask of INVPC field.
+	SCB_CFSR_INVPC                     = 0x40000   // Bit INVPC.
+	SCB_CFSR_INVPC_INVPC_0             = 0x0       // no invalid PC load UsageFault
+	SCB_CFSR_INVPC_INVPC_1             = 0x1       // the processor has attempted an illegal load of EXC_RETURN to the PC
+	SCB_CFSR_NOCP_Pos                  = 0x13      // Position of NOCP field.
+	SCB_CFSR_NOCP_Msk                  = 0x80000   // Bit mask of NOCP field.
+	SCB_CFSR_NOCP                      = 0x80000   // Bit NOCP.
+	SCB_CFSR_NOCP_NOCP_0               = 0x0       // no UsageFault caused by attempting to access a coprocessor
+	SCB_CFSR_NOCP_NOCP_1               = 0x1       // the processor has attempted to access a coprocessor
+	SCB_CFSR_UNALIGNED_Pos             = 0x18      // Position of UNALIGNED field.
+	SCB_CFSR_UNALIGNED_Msk             = 0x1000000 // Bit mask of UNALIGNED field.
+	SCB_CFSR_UNALIGNED                 = 0x1000000 // Bit UNALIGNED.
+	SCB_CFSR_UNALIGNED_UNALIGNED_0     = 0x0       // no unaligned access fault, or unaligned access trapping not enabled
+	SCB_CFSR_UNALIGNED_UNALIGNED_1     = 0x1       // the processor has made an unaligned memory access
+	SCB_CFSR_DIVBYZERO_Pos             = 0x19      // Position of DIVBYZERO field.
+	SCB_CFSR_DIVBYZERO_Msk             = 0x2000000 // Bit mask of DIVBYZERO field.
+	SCB_CFSR_DIVBYZERO                 = 0x2000000 // Bit DIVBYZERO.
+	SCB_CFSR_DIVBYZERO_DIVBYZERO_0     = 0x0       // no divide by zero fault, or divide by zero trapping not enabled
+	SCB_CFSR_DIVBYZERO_DIVBYZERO_1     = 0x1       // the processor has executed an SDIV or UDIV instruction with a divisor of 0
+
+	// HFSR: HardFault Status register
+	SCB_HFSR_VECTTBL_Pos         = 0x1        // Position of VECTTBL field.
+	SCB_HFSR_VECTTBL_Msk         = 0x2        // Bit mask of VECTTBL field.
+	SCB_HFSR_VECTTBL             = 0x2        // Bit VECTTBL.
+	SCB_HFSR_VECTTBL_VECTTBL_0   = 0x0        // no BusFault on vector table read
+	SCB_HFSR_VECTTBL_VECTTBL_1   = 0x1        // BusFault on vector table read
+	SCB_HFSR_FORCED_Pos          = 0x1e       // Position of FORCED field.
+	SCB_HFSR_FORCED_Msk          = 0x40000000 // Bit mask of FORCED field.
+	SCB_HFSR_FORCED              = 0x40000000 // Bit FORCED.
+	SCB_HFSR_FORCED_FORCED_0     = 0x0        // no forced HardFault
+	SCB_HFSR_FORCED_FORCED_1     = 0x1        // forced HardFault
+	SCB_HFSR_DEBUGEVT_Pos        = 0x1f       // Position of DEBUGEVT field.
+	SCB_HFSR_DEBUGEVT_Msk        = 0x80000000 // Bit mask of DEBUGEVT field.
+	SCB_HFSR_DEBUGEVT            = 0x80000000 // Bit DEBUGEVT.
+	SCB_HFSR_DEBUGEVT_DEBUGEVT_0 = 0x0        // No Debug event has occurred.
+	SCB_HFSR_DEBUGEVT_DEBUGEVT_1 = 0x1        // Debug event has occurred. The Debug Fault Status Register has been updated.
+
+	// DFSR: Debug Fault Status Register
+	SCB_DFSR_HALTED_Pos          = 0x0  // Position of HALTED field.
+	SCB_DFSR_HALTED_Msk          = 0x1  // Bit mask of HALTED field.
+	SCB_DFSR_HALTED              = 0x1  // Bit HALTED.
+	SCB_DFSR_HALTED_HALTED_0     = 0x0  // No active halt request debug event
+	SCB_DFSR_HALTED_HALTED_1     = 0x1  // Halt request debug event active
+	SCB_DFSR_BKPT_Pos            = 0x1  // Position of BKPT field.
+	SCB_DFSR_BKPT_Msk            = 0x2  // Bit mask of BKPT field.
+	SCB_DFSR_BKPT                = 0x2  // Bit BKPT.
+	SCB_DFSR_BKPT_BKPT_0         = 0x0  // No current breakpoint debug event
+	SCB_DFSR_BKPT_BKPT_1         = 0x1  // At least one current breakpoint debug event
+	SCB_DFSR_DWTTRAP_Pos         = 0x2  // Position of DWTTRAP field.
+	SCB_DFSR_DWTTRAP_Msk         = 0x4  // Bit mask of DWTTRAP field.
+	SCB_DFSR_DWTTRAP             = 0x4  // Bit DWTTRAP.
+	SCB_DFSR_DWTTRAP_DWTTRAP_0   = 0x0  // No current debug events generated by the DWT
+	SCB_DFSR_DWTTRAP_DWTTRAP_1   = 0x1  // At least one current debug event generated by the DWT
+	SCB_DFSR_VCATCH_Pos          = 0x3  // Position of VCATCH field.
+	SCB_DFSR_VCATCH_Msk          = 0x8  // Bit mask of VCATCH field.
+	SCB_DFSR_VCATCH              = 0x8  // Bit VCATCH.
+	SCB_DFSR_VCATCH_VCATCH_0     = 0x0  // No Vector catch triggered
+	SCB_DFSR_VCATCH_VCATCH_1     = 0x1  // Vector catch triggered
+	SCB_DFSR_EXTERNAL_Pos        = 0x4  // Position of EXTERNAL field.
+	SCB_DFSR_EXTERNAL_Msk        = 0x10 // Bit mask of EXTERNAL field.
+	SCB_DFSR_EXTERNAL            = 0x10 // Bit EXTERNAL.
+	SCB_DFSR_EXTERNAL_EXTERNAL_0 = 0x0  // No external debug request debug event
+	SCB_DFSR_EXTERNAL_EXTERNAL_1 = 0x1  // External debug request debug event
+
+	// MMFAR: MemManage Fault Address Register
+	SCB_MMFAR_ADDRESS_Pos = 0x0        // Position of ADDRESS field.
+	SCB_MMFAR_ADDRESS_Msk = 0xffffffff // Bit mask of ADDRESS field.
+
+	// BFAR: BusFault Address Register
+	SCB_BFAR_ADDRESS_Pos = 0x0        // Position of ADDRESS field.
+	SCB_BFAR_ADDRESS_Msk = 0xffffffff // Bit mask of ADDRESS field.
+)

src/device/arm64/arm64.go

@@ -0,0 +1,36 @@
+package arm64
+
+// Run the given assembly code. The code will be marked as having side effects,
+// as it doesn't produce output and thus would normally be eliminated by the
+// optimizer.
+func Asm(asm string)
+
+// Run the given inline assembly. The code will be marked as having side
+// effects, as it would otherwise be optimized away. The inline assembly string
+// recognizes template values in the form {name}, like so:
+//
+//     arm.AsmFull(
+//         "str {value}, {result}",
+//         map[string]interface{}{
+//             "value":  1
+//             "result": &dest,
+//         })
+//
+// You can use {} in the asm string (which expands to a register) to set the
+// return value.
+func AsmFull(asm string, regs map[string]interface{}) uintptr
+
+// Run the following system call (SVCall) with 0 arguments.
+func SVCall0(num uintptr) uintptr
+
+// Run the following system call (SVCall) with 1 argument.
+func SVCall1(num uintptr, a1 interface{}) uintptr
+
+// Run the following system call (SVCall) with 2 arguments.
+func SVCall2(num uintptr, a1, a2 interface{}) uintptr
+
+// Run the following system call (SVCall) with 3 arguments.
+func SVCall3(num uintptr, a1, a2, a3 interface{}) uintptr
+
+// Run the following system call (SVCall) with 4 arguments.
+func SVCall4(num uintptr, a1, a2, a3, a4 interface{}) uintptr

src/device/esp/esp32.S

@@ -0,0 +1,52 @@
+
+// The following definitions were copied from:
+// esp-idf/components/xtensa/include/xtensa/corebits.h
+#define PS_WOE_MASK                0x00040000
+#define PS_OWB_MASK                0x00000F00
+#define PS_CALLINC_MASK            0x00030000
+#define PS_WOE                     PS_WOE_MASK
+
+// Only calling it call_start_cpu0 for consistency with ESP-IDF.
+.section .text.call_start_cpu0
+1:
+    .long _stack_top
+.global call_start_cpu0
+call_start_cpu0:
+    // We need to set the stack pointer to a different value. This is somewhat
+    // complicated in the Xtensa architecture. The code below is a modified
+    // version of the following code:
+    // https://github.com/espressif/esp-idf/blob/c77c4ccf/components/xtensa/include/xt_instr_macros.h#L47
+
+    // Disable WOE.
+    rsr.ps a2
+    movi a3, ~(PS_WOE_MASK)
+    and a2, a2, a3
+    wsr.ps a2
+    rsync
+
+    // Set WINDOWBASE to 1 << WINDOWSTART.
+    rsr.windowbase  a2
+    ssl  a2
+    movi a2, 1
+    sll  a2, a2
+    wsr.windowstart a2
+    rsync
+
+    // Load new stack pointer.
+    l32r sp, 1b
+
+    // Re-enable WOE.
+    rsr.ps a2
+    movi a3, PS_WOE
+    or a2, a2, a3
+    wsr.ps a2
+    rsync
+
+    // Jump to the runtime start function written in Go.
+    j main
+
+.section .text.tinygo_scanCurrentStack
+.global tinygo_scanCurrentStack
+tinygo_scanCurrentStack:
+    // TODO: save callee saved registers on the stack
+    j tinygo_scanstack

src/device/esp/esp8266.S

@@ -0,0 +1,6 @@
+
+.section .text.tinygo_scanCurrentStack
+.global tinygo_scanCurrentStack
+tinygo_scanCurrentStack:
+    // TODO: save callee saved registers on the stack
+    j tinygo_scanstack

src/device/nxp/hardfault.go

@@ -0,0 +1,29 @@
+// Hand created file. DO NOT DELETE.
+// Hardfault aliases for definitions that have inconsistent naming (which are
+// auto-generated by gen-device-svd.go) among devices in package nxp.
+
+// +build nxp,!mimxrt1062
+
+package nxp
+
+const (
+	HardFault_CFSR_IACCVIOL    = SystemControl_CFSR_IACCVIOL
+	HardFault_CFSR_DACCVIOL    = SystemControl_CFSR_DACCVIOL
+	HardFault_CFSR_MUNSTKERR   = SystemControl_CFSR_MUNSTKERR
+	HardFault_CFSR_MSTKERR     = SystemControl_CFSR_MSTKERR
+	HardFault_CFSR_MLSPERR     = SystemControl_CFSR_MLSPERR
+	HardFault_CFSR_IBUSERR     = SystemControl_CFSR_IBUSERR
+	HardFault_CFSR_PRECISERR   = SystemControl_CFSR_PRECISERR
+	HardFault_CFSR_IMPRECISERR = SystemControl_CFSR_IMPRECISERR
+	HardFault_CFSR_UNSTKERR    = SystemControl_CFSR_UNSTKERR
+	HardFault_CFSR_STKERR      = SystemControl_CFSR_STKERR
+	HardFault_CFSR_LSPERR      = SystemControl_CFSR_LSPERR
+	HardFault_CFSR_UNDEFINSTR  = SystemControl_CFSR_UNDEFINSTR
+	HardFault_CFSR_INVSTATE    = SystemControl_CFSR_INVSTATE
+	HardFault_CFSR_INVPC       = SystemControl_CFSR_INVPC
+	HardFault_CFSR_NOCP        = SystemControl_CFSR_NOCP
+	HardFault_CFSR_UNALIGNED   = SystemControl_CFSR_UNALIGNED
+	HardFault_CFSR_DIVBYZERO   = SystemControl_CFSR_DIVBYZERO
+	HardFault_CFSR_MMARVALID   = SystemControl_CFSR_MMARVALID
+	HardFault_CFSR_BFARVALID   = SystemControl_CFSR_BFARVALID
+)

src/device/nxp/mimxrt1062_clock.go

@@ -0,0 +1,529 @@
+// Hand created file. DO NOT DELETE.
+// Type definitions, fields, and constants associated with various clocks and
+// peripherals of the NXP MIMXRT1062.
+
+// +build nxp,mimxrt1062
+
+package nxp
+
+import (
+	"runtime/volatile"
+	"unsafe"
+)
+
+// Clock represents an individual peripheral clock that may be enabled/disabled
+// at runtime. Clocks also have a method `Mux` for selecting the clock source
+// and a method `Div` for selecting the hardware divisor. Note that many
+// peripherals have an independent prescalar configuration applied to the output
+// of this divisor.
+type (
+	Clock     uint32
+	ClockMode uint8
+)
+
+// Enable activates or deactivates the clock gate of receiver Clock c.
+func (c Clock) Enable(enable bool) {
+	if enable {
+		c.setGate(clockNeededRunWait)
+	} else {
+		c.setGate(clockNotNeeded)
+	}
+}
+
+// Mux selects a clock source for the mux of the receiver Clock c.
+func (c Clock) Mux(mux uint32) { c.setCcm(mux) }
+
+// Div configures the prescalar divisor of the receiver Clock c.
+func (c Clock) Div(div uint32) { c.setCcm(div) }
+
+const (
+	ClockModeRun  ClockMode = 0 // Remain in run mode
+	ClockModeWait ClockMode = 1 // Transfer to wait mode
+	ClockModeStop ClockMode = 2 // Transfer to stop mode
+)
+
+// Set configures the run mode of the MCU.
+func (m ClockMode) Set() {
+	CCM.CLPCR.Set((CCM.CLPCR.Get() & ^uint32(CCM_CLPCR_LPM_Msk)) |
+		((uint32(m) << CCM_CLPCR_LPM_Pos) & CCM_CLPCR_LPM_Msk))
+}
+
+// Named oscillators
+const (
+	ClockCpu         Clock = 0x0  // CPU clock
+	ClockAhb         Clock = 0x1  // AHB clock
+	ClockSemc        Clock = 0x2  // SEMC clock
+	ClockIpg         Clock = 0x3  // IPG clock
+	ClockPer         Clock = 0x4  // PER clock
+	ClockOsc         Clock = 0x5  // OSC clock selected by PMU_LOWPWR_CTRL[OSC_SEL]
+	ClockRtc         Clock = 0x6  // RTC clock (RTCCLK)
+	ClockArmPll      Clock = 0x7  // ARMPLLCLK
+	ClockUsb1Pll     Clock = 0x8  // USB1PLLCLK
+	ClockUsb1PllPfd0 Clock = 0x9  // USB1PLLPDF0CLK
+	ClockUsb1PllPfd1 Clock = 0xA  // USB1PLLPFD1CLK
+	ClockUsb1PllPfd2 Clock = 0xB  // USB1PLLPFD2CLK
+	ClockUsb1PllPfd3 Clock = 0xC  // USB1PLLPFD3CLK
+	ClockUsb2Pll     Clock = 0xD  // USB2PLLCLK
+	ClockSysPll      Clock = 0xE  // SYSPLLCLK
+	ClockSysPllPfd0  Clock = 0xF  // SYSPLLPDF0CLK
+	ClockSysPllPfd1  Clock = 0x10 // SYSPLLPFD1CLK
+	ClockSysPllPfd2  Clock = 0x11 // SYSPLLPFD2CLK
+	ClockSysPllPfd3  Clock = 0x12 // SYSPLLPFD3CLK
+	ClockEnetPll0    Clock = 0x13 // Enet PLLCLK ref_enetpll0
+	ClockEnetPll1    Clock = 0x14 // Enet PLLCLK ref_enetpll1
+	ClockEnetPll2    Clock = 0x15 // Enet PLLCLK ref_enetpll2
+	ClockAudioPll    Clock = 0x16 // Audio PLLCLK
+	ClockVideoPll    Clock = 0x17 // Video PLLCLK
+)
+
+// Named clocks of integrated peripherals
+const (
+	ClockIpAipsTz1     Clock = (0 << 8) | CCM_CCGR0_CG0_Pos  // CCGR0, CG0
+	ClockIpAipsTz2     Clock = (0 << 8) | CCM_CCGR0_CG1_Pos  // CCGR0, CG1
+	ClockIpMqs         Clock = (0 << 8) | CCM_CCGR0_CG2_Pos  // CCGR0, CG2
+	ClockIpFlexSpiExsc Clock = (0 << 8) | CCM_CCGR0_CG3_Pos  // CCGR0, CG3
+	ClockIpSimMMain    Clock = (0 << 8) | CCM_CCGR0_CG4_Pos  // CCGR0, CG4
+	ClockIpDcp         Clock = (0 << 8) | CCM_CCGR0_CG5_Pos  // CCGR0, CG5
+	ClockIpLpuart3     Clock = (0 << 8) | CCM_CCGR0_CG6_Pos  // CCGR0, CG6
+	ClockIpCan1        Clock = (0 << 8) | CCM_CCGR0_CG7_Pos  // CCGR0, CG7
+	ClockIpCan1S       Clock = (0 << 8) | CCM_CCGR0_CG8_Pos  // CCGR0, CG8
+	ClockIpCan2        Clock = (0 << 8) | CCM_CCGR0_CG9_Pos  // CCGR0, CG9
+	ClockIpCan2S       Clock = (0 << 8) | CCM_CCGR0_CG10_Pos // CCGR0, CG10
+	ClockIpTrace       Clock = (0 << 8) | CCM_CCGR0_CG11_Pos // CCGR0, CG11
+	ClockIpGpt2        Clock = (0 << 8) | CCM_CCGR0_CG12_Pos // CCGR0, CG12
+	ClockIpGpt2S       Clock = (0 << 8) | CCM_CCGR0_CG13_Pos // CCGR0, CG13
+	ClockIpLpuart2     Clock = (0 << 8) | CCM_CCGR0_CG14_Pos // CCGR0, CG14
+	ClockIpGpio2       Clock = (0 << 8) | CCM_CCGR0_CG15_Pos // CCGR0, CG15
+
+	ClockIpLpspi1   Clock = (1 << 8) | CCM_CCGR1_CG0_Pos  // CCGR1, CG0
+	ClockIpLpspi2   Clock = (1 << 8) | CCM_CCGR1_CG1_Pos  // CCGR1, CG1
+	ClockIpLpspi3   Clock = (1 << 8) | CCM_CCGR1_CG2_Pos  // CCGR1, CG2
+	ClockIpLpspi4   Clock = (1 << 8) | CCM_CCGR1_CG3_Pos  // CCGR1, CG3
+	ClockIpAdc2     Clock = (1 << 8) | CCM_CCGR1_CG4_Pos  // CCGR1, CG4
+	ClockIpEnet     Clock = (1 << 8) | CCM_CCGR1_CG5_Pos  // CCGR1, CG5
+	ClockIpPit      Clock = (1 << 8) | CCM_CCGR1_CG6_Pos  // CCGR1, CG6
+	ClockIpAoi2     Clock = (1 << 8) | CCM_CCGR1_CG7_Pos  // CCGR1, CG7
+	ClockIpAdc1     Clock = (1 << 8) | CCM_CCGR1_CG8_Pos  // CCGR1, CG8
+	ClockIpSemcExsc Clock = (1 << 8) | CCM_CCGR1_CG9_Pos  // CCGR1, CG9
+	ClockIpGpt1     Clock = (1 << 8) | CCM_CCGR1_CG10_Pos // CCGR1, CG10
+	ClockIpGpt1S    Clock = (1 << 8) | CCM_CCGR1_CG11_Pos // CCGR1, CG11
+	ClockIpLpuart4  Clock = (1 << 8) | CCM_CCGR1_CG12_Pos // CCGR1, CG12
+	ClockIpGpio1    Clock = (1 << 8) | CCM_CCGR1_CG13_Pos // CCGR1, CG13
+	ClockIpCsu      Clock = (1 << 8) | CCM_CCGR1_CG14_Pos // CCGR1, CG14
+	ClockIpGpio5    Clock = (1 << 8) | CCM_CCGR1_CG15_Pos // CCGR1, CG15
+
+	ClockIpOcramExsc  Clock = (2 << 8) | CCM_CCGR2_CG0_Pos  // CCGR2, CG0
+	ClockIpCsi        Clock = (2 << 8) | CCM_CCGR2_CG1_Pos  // CCGR2, CG1
+	ClockIpIomuxcSnvs Clock = (2 << 8) | CCM_CCGR2_CG2_Pos  // CCGR2, CG2
+	ClockIpLpi2c1     Clock = (2 << 8) | CCM_CCGR2_CG3_Pos  // CCGR2, CG3
+	ClockIpLpi2c2     Clock = (2 << 8) | CCM_CCGR2_CG4_Pos  // CCGR2, CG4
+	ClockIpLpi2c3     Clock = (2 << 8) | CCM_CCGR2_CG5_Pos  // CCGR2, CG5
+	ClockIpOcotp      Clock = (2 << 8) | CCM_CCGR2_CG6_Pos  // CCGR2, CG6
+	ClockIpXbar3      Clock = (2 << 8) | CCM_CCGR2_CG7_Pos  // CCGR2, CG7
+	ClockIpIpmux1     Clock = (2 << 8) | CCM_CCGR2_CG8_Pos  // CCGR2, CG8
+	ClockIpIpmux2     Clock = (2 << 8) | CCM_CCGR2_CG9_Pos  // CCGR2, CG9
+	ClockIpIpmux3     Clock = (2 << 8) | CCM_CCGR2_CG10_Pos // CCGR2, CG10
+	ClockIpXbar1      Clock = (2 << 8) | CCM_CCGR2_CG11_Pos // CCGR2, CG11
+	ClockIpXbar2      Clock = (2 << 8) | CCM_CCGR2_CG12_Pos // CCGR2, CG12
+	ClockIpGpio3      Clock = (2 << 8) | CCM_CCGR2_CG13_Pos // CCGR2, CG13
+	ClockIpLcd        Clock = (2 << 8) | CCM_CCGR2_CG14_Pos // CCGR2, CG14
+	ClockIpPxp        Clock = (2 << 8) | CCM_CCGR2_CG15_Pos // CCGR2, CG15
+
+	ClockIpFlexio2       Clock = (3 << 8) | CCM_CCGR3_CG0_Pos  // CCGR3, CG0
+	ClockIpLpuart5       Clock = (3 << 8) | CCM_CCGR3_CG1_Pos  // CCGR3, CG1
+	ClockIpSemc          Clock = (3 << 8) | CCM_CCGR3_CG2_Pos  // CCGR3, CG2
+	ClockIpLpuart6       Clock = (3 << 8) | CCM_CCGR3_CG3_Pos  // CCGR3, CG3
+	ClockIpAoi1          Clock = (3 << 8) | CCM_CCGR3_CG4_Pos  // CCGR3, CG4
+	ClockIpLcdPixel      Clock = (3 << 8) | CCM_CCGR3_CG5_Pos  // CCGR3, CG5
+	ClockIpGpio4         Clock = (3 << 8) | CCM_CCGR3_CG6_Pos  // CCGR3, CG6
+	ClockIpEwm0          Clock = (3 << 8) | CCM_CCGR3_CG7_Pos  // CCGR3, CG7
+	ClockIpWdog1         Clock = (3 << 8) | CCM_CCGR3_CG8_Pos  // CCGR3, CG8
+	ClockIpFlexRam       Clock = (3 << 8) | CCM_CCGR3_CG9_Pos  // CCGR3, CG9
+	ClockIpAcmp1         Clock = (3 << 8) | CCM_CCGR3_CG10_Pos // CCGR3, CG10
+	ClockIpAcmp2         Clock = (3 << 8) | CCM_CCGR3_CG11_Pos // CCGR3, CG11
+	ClockIpAcmp3         Clock = (3 << 8) | CCM_CCGR3_CG12_Pos // CCGR3, CG12
+	ClockIpAcmp4         Clock = (3 << 8) | CCM_CCGR3_CG13_Pos // CCGR3, CG13
+	ClockIpOcram         Clock = (3 << 8) | CCM_CCGR3_CG14_Pos // CCGR3, CG14
+	ClockIpIomuxcSnvsGpr Clock = (3 << 8) | CCM_CCGR3_CG15_Pos // CCGR3, CG15
+
+	ClockIpIomuxc    Clock = (4 << 8) | CCM_CCGR4_CG1_Pos  // CCGR4, CG1
+	ClockIpIomuxcGpr Clock = (4 << 8) | CCM_CCGR4_CG2_Pos  // CCGR4, CG2
+	ClockIpBee       Clock = (4 << 8) | CCM_CCGR4_CG3_Pos  // CCGR4, CG3
+	ClockIpSimM7     Clock = (4 << 8) | CCM_CCGR4_CG4_Pos  // CCGR4, CG4
+	ClockIpTsc       Clock = (4 << 8) | CCM_CCGR4_CG5_Pos  // CCGR4, CG5
+	ClockIpSimM      Clock = (4 << 8) | CCM_CCGR4_CG6_Pos  // CCGR4, CG6
+	ClockIpSimEms    Clock = (4 << 8) | CCM_CCGR4_CG7_Pos  // CCGR4, CG7
+	ClockIpPwm1      Clock = (4 << 8) | CCM_CCGR4_CG8_Pos  // CCGR4, CG8
+	ClockIpPwm2      Clock = (4 << 8) | CCM_CCGR4_CG9_Pos  // CCGR4, CG9
+	ClockIpPwm3      Clock = (4 << 8) | CCM_CCGR4_CG10_Pos // CCGR4, CG10
+	ClockIpPwm4      Clock = (4 << 8) | CCM_CCGR4_CG11_Pos // CCGR4, CG11
+	ClockIpEnc1      Clock = (4 << 8) | CCM_CCGR4_CG12_Pos // CCGR4, CG12
+	ClockIpEnc2      Clock = (4 << 8) | CCM_CCGR4_CG13_Pos // CCGR4, CG13
+	ClockIpEnc3      Clock = (4 << 8) | CCM_CCGR4_CG14_Pos // CCGR4, CG14
+	ClockIpEnc4      Clock = (4 << 8) | CCM_CCGR4_CG15_Pos // CCGR4, CG15
+
+	ClockIpRom     Clock = (5 << 8) | CCM_CCGR5_CG0_Pos  // CCGR5, CG0
+	ClockIpFlexio1 Clock = (5 << 8) | CCM_CCGR5_CG1_Pos  // CCGR5, CG1
+	ClockIpWdog3   Clock = (5 << 8) | CCM_CCGR5_CG2_Pos  // CCGR5, CG2
+	ClockIpDma     Clock = (5 << 8) | CCM_CCGR5_CG3_Pos  // CCGR5, CG3
+	ClockIpKpp     Clock = (5 << 8) | CCM_CCGR5_CG4_Pos  // CCGR5, CG4
+	ClockIpWdog2   Clock = (5 << 8) | CCM_CCGR5_CG5_Pos  // CCGR5, CG5
+	ClockIpAipsTz4 Clock = (5 << 8) | CCM_CCGR5_CG6_Pos  // CCGR5, CG6
+	ClockIpSpdif   Clock = (5 << 8) | CCM_CCGR5_CG7_Pos  // CCGR5, CG7
+	ClockIpSimMain Clock = (5 << 8) | CCM_CCGR5_CG8_Pos  // CCGR5, CG8
+	ClockIpSai1    Clock = (5 << 8) | CCM_CCGR5_CG9_Pos  // CCGR5, CG9
+	ClockIpSai2    Clock = (5 << 8) | CCM_CCGR5_CG10_Pos // CCGR5, CG10
+	ClockIpSai3    Clock = (5 << 8) | CCM_CCGR5_CG11_Pos // CCGR5, CG11
+	ClockIpLpuart1 Clock = (5 << 8) | CCM_CCGR5_CG12_Pos // CCGR5, CG12
+	ClockIpLpuart7 Clock = (5 << 8) | CCM_CCGR5_CG13_Pos // CCGR5, CG13
+	ClockIpSnvsHp  Clock = (5 << 8) | CCM_CCGR5_CG14_Pos // CCGR5, CG14
+	ClockIpSnvsLp  Clock = (5 << 8) | CCM_CCGR5_CG15_Pos // CCGR5, CG15
+
+	ClockIpUsbOh3  Clock = (6 << 8) | CCM_CCGR6_CG0_Pos  // CCGR6, CG0
+	ClockIpUsdhc1  Clock = (6 << 8) | CCM_CCGR6_CG1_Pos  // CCGR6, CG1
+	ClockIpUsdhc2  Clock = (6 << 8) | CCM_CCGR6_CG2_Pos  // CCGR6, CG2
+	ClockIpDcdc    Clock = (6 << 8) | CCM_CCGR6_CG3_Pos  // CCGR6, CG3
+	ClockIpIpmux4  Clock = (6 << 8) | CCM_CCGR6_CG4_Pos  // CCGR6, CG4
+	ClockIpFlexSpi Clock = (6 << 8) | CCM_CCGR6_CG5_Pos  // CCGR6, CG5
+	ClockIpTrng    Clock = (6 << 8) | CCM_CCGR6_CG6_Pos  // CCGR6, CG6
+	ClockIpLpuart8 Clock = (6 << 8) | CCM_CCGR6_CG7_Pos  // CCGR6, CG7
+	ClockIpTimer4  Clock = (6 << 8) | CCM_CCGR6_CG8_Pos  // CCGR6, CG8
+	ClockIpAipsTz3 Clock = (6 << 8) | CCM_CCGR6_CG9_Pos  // CCGR6, CG9
+	ClockIpSimPer  Clock = (6 << 8) | CCM_CCGR6_CG10_Pos // CCGR6, CG10
+	ClockIpAnadig  Clock = (6 << 8) | CCM_CCGR6_CG11_Pos // CCGR6, CG11
+	ClockIpLpi2c4  Clock = (6 << 8) | CCM_CCGR6_CG12_Pos // CCGR6, CG12
+	ClockIpTimer1  Clock = (6 << 8) | CCM_CCGR6_CG13_Pos // CCGR6, CG13
+	ClockIpTimer2  Clock = (6 << 8) | CCM_CCGR6_CG14_Pos // CCGR6, CG14
+	ClockIpTimer3  Clock = (6 << 8) | CCM_CCGR6_CG15_Pos // CCGR6, CG15
+
+	ClockIpEnet2    Clock = (7 << 8) | CCM_CCGR7_CG0_Pos // CCGR7, CG0
+	ClockIpFlexSpi2 Clock = (7 << 8) | CCM_CCGR7_CG1_Pos // CCGR7, CG1
+	ClockIpAxbsL    Clock = (7 << 8) | CCM_CCGR7_CG2_Pos // CCGR7, CG2
+	ClockIpCan3     Clock = (7 << 8) | CCM_CCGR7_CG3_Pos // CCGR7, CG3
+	ClockIpCan3S    Clock = (7 << 8) | CCM_CCGR7_CG4_Pos // CCGR7, CG4
+	ClockIpAipsLite Clock = (7 << 8) | CCM_CCGR7_CG5_Pos // CCGR7, CG5
+	ClockIpFlexio3  Clock = (7 << 8) | CCM_CCGR7_CG6_Pos // CCGR7, CG6
+)
+
+// PLL name
+const (
+	ClockPllArm     Clock = ((offPllArm & 0xFFF) << 16) | CCM_ANALOG_PLL_ARM_ENABLE_Pos            // PLL ARM
+	ClockPllSys     Clock = ((offPllSys & 0xFFF) << 16) | CCM_ANALOG_PLL_SYS_ENABLE_Pos            // PLL SYS
+	ClockPllUsb1    Clock = ((offPllUsb1 & 0xFFF) << 16) | CCM_ANALOG_PLL_USB1_ENABLE_Pos          // PLL USB1
+	ClockPllAudio   Clock = ((offPllAudio & 0xFFF) << 16) | CCM_ANALOG_PLL_AUDIO_ENABLE_Pos        // PLL Audio
+	ClockPllVideo   Clock = ((offPllVideo & 0xFFF) << 16) | CCM_ANALOG_PLL_VIDEO_ENABLE_Pos        // PLL Video
+	ClockPllEnet    Clock = ((offPllEnet & 0xFFF) << 16) | CCM_ANALOG_PLL_ENET_ENABLE_Pos          // PLL Enet0
+	ClockPllEnet2   Clock = ((offPllEnet & 0xFFF) << 16) | CCM_ANALOG_PLL_ENET_ENET2_REF_EN_Pos    // PLL Enet1
+	ClockPllEnet25M Clock = ((offPllEnet & 0xFFF) << 16) | CCM_ANALOG_PLL_ENET_ENET_25M_REF_EN_Pos // PLL Enet2
+	ClockPllUsb2    Clock = ((offPllUsb2 & 0xFFF) << 16) | CCM_ANALOG_PLL_USB2_ENABLE_Pos          // PLL USB2
+)
+
+// PLL PFD name
+const (
+	ClockPfd0 Clock = 0 // PLL PFD0
+	ClockPfd1 Clock = 1 // PLL PFD1
+	ClockPfd2 Clock = 2 // PLL PFD2
+	ClockPfd3 Clock = 3 // PLL PFD3
+)
+
+// Named clock muxes of integrated peripherals
+const (
+	MuxIpPll3Sw     Clock = (offCCSR & 0xFF) | (CCM_CCSR_PLL3_SW_CLK_SEL_Pos << 8) | (((CCM_CCSR_PLL3_SW_CLK_SEL_Msk >> CCM_CCSR_PLL3_SW_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                          // pll3_sw_clk mux name
+	MuxIpPeriph     Clock = (offCBCDR & 0xFF) | (CCM_CBCDR_PERIPH_CLK_SEL_Pos << 8) | (((CCM_CBCDR_PERIPH_CLK_SEL_Msk >> CCM_CBCDR_PERIPH_CLK_SEL_Pos) & 0x1FFF) << 13) | (CCM_CDHIPR_PERIPH_CLK_SEL_BUSY_Pos << 26) // periph mux name
+	MuxIpSemcAlt    Clock = (offCBCDR & 0xFF) | (CCM_CBCDR_SEMC_ALT_CLK_SEL_Pos << 8) | (((CCM_CBCDR_SEMC_ALT_CLK_SEL_Msk >> CCM_CBCDR_SEMC_ALT_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                   // semc mux name
+	MuxIpSemc       Clock = (offCBCDR & 0xFF) | (CCM_CBCDR_SEMC_CLK_SEL_Pos << 8) | (((CCM_CBCDR_SEMC_CLK_SEL_Msk >> CCM_CBCDR_SEMC_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                               // semc mux name
+	MuxIpPrePeriph  Clock = (offCBCMR & 0xFF) | (CCM_CBCMR_PRE_PERIPH_CLK_SEL_Pos << 8) | (((CCM_CBCMR_PRE_PERIPH_CLK_SEL_Msk >> CCM_CBCMR_PRE_PERIPH_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)             // pre-periph mux name
+	MuxIpTrace      Clock = (offCBCMR & 0xFF) | (CCM_CBCMR_TRACE_CLK_SEL_Pos << 8) | (((CCM_CBCMR_TRACE_CLK_SEL_Msk >> CCM_CBCMR_TRACE_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                            // trace mux name
+	MuxIpPeriphClk2 Clock = (offCBCMR & 0xFF) | (CCM_CBCMR_PERIPH_CLK2_SEL_Pos << 8) | (((CCM_CBCMR_PERIPH_CLK2_SEL_Msk >> CCM_CBCMR_PERIPH_CLK2_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                      // periph clock2 mux name
+	MuxIpFlexSpi2   Clock = (offCBCMR & 0xFF) | (CCM_CBCMR_FLEXSPI2_CLK_SEL_Pos << 8) | (((CCM_CBCMR_FLEXSPI2_CLK_SEL_Msk >> CCM_CBCMR_FLEXSPI2_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                   // flexspi2 mux name
+	MuxIpLpspi      Clock = (offCBCMR & 0xFF) | (CCM_CBCMR_LPSPI_CLK_SEL_Pos << 8) | (((CCM_CBCMR_LPSPI_CLK_SEL_Msk >> CCM_CBCMR_LPSPI_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                            // lpspi mux name
+	MuxIpFlexSpi    Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_FLEXSPI_CLK_SEL_Pos << 8) | (((CCM_CSCMR1_FLEXSPI_CLK_SEL_Msk >> CCM_CSCMR1_FLEXSPI_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                  // flexspi mux name
+	MuxIpUsdhc2     Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_USDHC2_CLK_SEL_Pos << 8) | (((CCM_CSCMR1_USDHC2_CLK_SEL_Msk >> CCM_CSCMR1_USDHC2_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                     // usdhc2 mux name
+	MuxIpUsdhc1     Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_USDHC1_CLK_SEL_Pos << 8) | (((CCM_CSCMR1_USDHC1_CLK_SEL_Msk >> CCM_CSCMR1_USDHC1_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                     // usdhc1 mux name
+	MuxIpSai3       Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_SAI3_CLK_SEL_Pos << 8) | (((CCM_CSCMR1_SAI3_CLK_SEL_Msk >> CCM_CSCMR1_SAI3_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                           // sai3 mux name
+	MuxIpSai2       Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_SAI2_CLK_SEL_Pos << 8) | (((CCM_CSCMR1_SAI2_CLK_SEL_Msk >> CCM_CSCMR1_SAI2_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                           // sai2 mux name
+	MuxIpSai1       Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_SAI1_CLK_SEL_Pos << 8) | (((CCM_CSCMR1_SAI1_CLK_SEL_Msk >> CCM_CSCMR1_SAI1_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                           // sai1 mux name
+	MuxIpPerclk     Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_PERCLK_CLK_SEL_Pos << 8) | (((CCM_CSCMR1_PERCLK_CLK_SEL_Msk >> CCM_CSCMR1_PERCLK_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                     // perclk mux name
+	MuxIpFlexio2    Clock = (offCSCMR2 & 0xFF) | (CCM_CSCMR2_FLEXIO2_CLK_SEL_Pos << 8) | (((CCM_CSCMR2_FLEXIO2_CLK_SEL_Msk >> CCM_CSCMR2_FLEXIO2_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                  // flexio2 mux name
+	MuxIpCan        Clock = (offCSCMR2 & 0xFF) | (CCM_CSCMR2_CAN_CLK_SEL_Pos << 8) | (((CCM_CSCMR2_CAN_CLK_SEL_Msk >> CCM_CSCMR2_CAN_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                              // can mux name
+	MuxIpUart       Clock = (offCSCDR1 & 0xFF) | (CCM_CSCDR1_UART_CLK_SEL_Pos << 8) | (((CCM_CSCDR1_UART_CLK_SEL_Msk >> CCM_CSCDR1_UART_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                           // uart mux name
+	MuxIpSpdif      Clock = (offCDCDR & 0xFF) | (CCM_CDCDR_SPDIF0_CLK_SEL_Pos << 8) | (((CCM_CDCDR_SPDIF0_CLK_SEL_Msk >> CCM_CDCDR_SPDIF0_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                         // spdif mux name
+	MuxIpFlexio1    Clock = (offCDCDR & 0xFF) | (CCM_CDCDR_FLEXIO1_CLK_SEL_Pos << 8) | (((CCM_CDCDR_FLEXIO1_CLK_SEL_Msk >> CCM_CDCDR_FLEXIO1_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                      // flexio1 mux name
+	MuxIpLpi2c      Clock = (offCSCDR2 & 0xFF) | (CCM_CSCDR2_LPI2C_CLK_SEL_Pos << 8) | (((CCM_CSCDR2_LPI2C_CLK_SEL_Msk >> CCM_CSCDR2_LPI2C_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                        // lpi2c mux name
+	MuxIpLcdifPre   Clock = (offCSCDR2 & 0xFF) | (CCM_CSCDR2_LCDIF_PRE_CLK_SEL_Pos << 8) | (((CCM_CSCDR2_LCDIF_PRE_CLK_SEL_Msk >> CCM_CSCDR2_LCDIF_PRE_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)            // lcdif pre mux name
+	MuxIpCsi        Clock = (offCSCDR3 & 0xFF) | (CCM_CSCDR3_CSI_CLK_SEL_Pos << 8) | (((CCM_CSCDR3_CSI_CLK_SEL_Msk >> CCM_CSCDR3_CSI_CLK_SEL_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                              // csi mux name
+)
+
+// Named hardware clock divisors of integrated peripherals
+const (
+	DivIpArm        Clock = (offCACRR & 0xFF) | (CCM_CACRR_ARM_PODF_Pos << 8) | (((CCM_CACRR_ARM_PODF_Msk >> CCM_CACRR_ARM_PODF_Pos) & 0x1FFF) << 13) | (CCM_CDHIPR_ARM_PODF_BUSY_Pos << 26)           // core div name
+	DivIpPeriphClk2 Clock = (offCBCDR & 0xFF) | (CCM_CBCDR_PERIPH_CLK2_PODF_Pos << 8) | (((CCM_CBCDR_PERIPH_CLK2_PODF_Msk >> CCM_CBCDR_PERIPH_CLK2_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)     // periph clock2 div name
+	DivIpSemc       Clock = (offCBCDR & 0xFF) | (CCM_CBCDR_SEMC_PODF_Pos << 8) | (((CCM_CBCDR_SEMC_PODF_Msk >> CCM_CBCDR_SEMC_PODF_Pos) & 0x1FFF) << 13) | (CCM_CDHIPR_SEMC_PODF_BUSY_Pos << 26)       // semc div name
+	DivIpAhb        Clock = (offCBCDR & 0xFF) | (CCM_CBCDR_AHB_PODF_Pos << 8) | (((CCM_CBCDR_AHB_PODF_Msk >> CCM_CBCDR_AHB_PODF_Pos) & 0x1FFF) << 13) | (CCM_CDHIPR_AHB_PODF_BUSY_Pos << 26)           // ahb div name
+	DivIpIpg        Clock = (offCBCDR & 0xFF) | (CCM_CBCDR_IPG_PODF_Pos << 8) | (((CCM_CBCDR_IPG_PODF_Msk >> CCM_CBCDR_IPG_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                             // ipg div name
+	DivIpFlexSpi2   Clock = (offCBCMR & 0xFF) | (CCM_CBCMR_FLEXSPI2_PODF_Pos << 8) | (((CCM_CBCMR_FLEXSPI2_PODF_Msk >> CCM_CBCMR_FLEXSPI2_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)              // flexspi2 div name
+	DivIpLpspi      Clock = (offCBCMR & 0xFF) | (CCM_CBCMR_LPSPI_PODF_Pos << 8) | (((CCM_CBCMR_LPSPI_PODF_Msk >> CCM_CBCMR_LPSPI_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                       // lpspi div name
+	DivIpLcdif      Clock = (offCBCMR & 0xFF) | (CCM_CBCMR_LCDIF_PODF_Pos << 8) | (((CCM_CBCMR_LCDIF_PODF_Msk >> CCM_CBCMR_LCDIF_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                       // lcdif div name
+	DivIpFlexSpi    Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_FLEXSPI_PODF_Pos << 8) | (((CCM_CSCMR1_FLEXSPI_PODF_Msk >> CCM_CSCMR1_FLEXSPI_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)             // flexspi div name
+	DivIpPerclk     Clock = (offCSCMR1 & 0xFF) | (CCM_CSCMR1_PERCLK_PODF_Pos << 8) | (((CCM_CSCMR1_PERCLK_PODF_Msk >> CCM_CSCMR1_PERCLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                // perclk div name
+	DivIpCan        Clock = (offCSCMR2 & 0xFF) | (CCM_CSCMR2_CAN_CLK_PODF_Pos << 8) | (((CCM_CSCMR2_CAN_CLK_PODF_Msk >> CCM_CSCMR2_CAN_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)             // can div name
+	DivIpTrace      Clock = (offCSCDR1 & 0xFF) | (CCM_CSCDR1_TRACE_PODF_Pos << 8) | (((CCM_CSCDR1_TRACE_PODF_Msk >> CCM_CSCDR1_TRACE_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                   // trace div name
+	DivIpUsdhc2     Clock = (offCSCDR1 & 0xFF) | (CCM_CSCDR1_USDHC2_PODF_Pos << 8) | (((CCM_CSCDR1_USDHC2_PODF_Msk >> CCM_CSCDR1_USDHC2_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                // usdhc2 div name
+	DivIpUsdhc1     Clock = (offCSCDR1 & 0xFF) | (CCM_CSCDR1_USDHC1_PODF_Pos << 8) | (((CCM_CSCDR1_USDHC1_PODF_Msk >> CCM_CSCDR1_USDHC1_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                // usdhc1 div name
+	DivIpUart       Clock = (offCSCDR1 & 0xFF) | (CCM_CSCDR1_UART_CLK_PODF_Pos << 8) | (((CCM_CSCDR1_UART_CLK_PODF_Msk >> CCM_CSCDR1_UART_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)          // uart div name
+	DivIpFlexio2    Clock = (offCS1CDR & 0xFF) | (CCM_CS1CDR_FLEXIO2_CLK_PODF_Pos << 8) | (((CCM_CS1CDR_FLEXIO2_CLK_PODF_Msk >> CCM_CS1CDR_FLEXIO2_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26) // flexio2 pre div name
+	DivIpSai3Pre    Clock = (offCS1CDR & 0xFF) | (CCM_CS1CDR_SAI3_CLK_PRED_Pos << 8) | (((CCM_CS1CDR_SAI3_CLK_PRED_Msk >> CCM_CS1CDR_SAI3_CLK_PRED_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)          // sai3 pre div name
+	DivIpSai3       Clock = (offCS1CDR & 0xFF) | (CCM_CS1CDR_SAI3_CLK_PODF_Pos << 8) | (((CCM_CS1CDR_SAI3_CLK_PODF_Msk >> CCM_CS1CDR_SAI3_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)          // sai3 div name
+	DivIpFlexio2Pre Clock = (offCS1CDR & 0xFF) | (CCM_CS1CDR_FLEXIO2_CLK_PRED_Pos << 8) | (((CCM_CS1CDR_FLEXIO2_CLK_PRED_Msk >> CCM_CS1CDR_FLEXIO2_CLK_PRED_Pos) & 0x1FFF) << 13) | (noBusyWait << 26) // sai3 pre div name
+	DivIpSai1Pre    Clock = (offCS1CDR & 0xFF) | (CCM_CS1CDR_SAI1_CLK_PRED_Pos << 8) | (((CCM_CS1CDR_SAI1_CLK_PRED_Msk >> CCM_CS1CDR_SAI1_CLK_PRED_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)          // sai1 pre div name
+	DivIpSai1       Clock = (offCS1CDR & 0xFF) | (CCM_CS1CDR_SAI1_CLK_PODF_Pos << 8) | (((CCM_CS1CDR_SAI1_CLK_PODF_Msk >> CCM_CS1CDR_SAI1_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)          // sai1 div name
+	DivIpSai2Pre    Clock = (offCS2CDR & 0xFF) | (CCM_CS2CDR_SAI2_CLK_PRED_Pos << 8) | (((CCM_CS2CDR_SAI2_CLK_PRED_Msk >> CCM_CS2CDR_SAI2_CLK_PRED_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)          // sai2 pre div name
+	DivIpSai2       Clock = (offCS2CDR & 0xFF) | (CCM_CS2CDR_SAI2_CLK_PODF_Pos << 8) | (((CCM_CS2CDR_SAI2_CLK_PODF_Msk >> CCM_CS2CDR_SAI2_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)          // sai2 div name
+	DivIpSpdif0Pre  Clock = (offCDCDR & 0xFF) | (CCM_CDCDR_SPDIF0_CLK_PRED_Pos << 8) | (((CCM_CDCDR_SPDIF0_CLK_PRED_Msk >> CCM_CDCDR_SPDIF0_CLK_PRED_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)        // spdif pre div name
+	DivIpSpdif0     Clock = (offCDCDR & 0xFF) | (CCM_CDCDR_SPDIF0_CLK_PODF_Pos << 8) | (((CCM_CDCDR_SPDIF0_CLK_PODF_Msk >> CCM_CDCDR_SPDIF0_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)        // spdif div name
+	DivIpFlexio1Pre Clock = (offCDCDR & 0xFF) | (CCM_CDCDR_FLEXIO1_CLK_PRED_Pos << 8) | (((CCM_CDCDR_FLEXIO1_CLK_PRED_Msk >> CCM_CDCDR_FLEXIO1_CLK_PRED_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)     // flexio1 pre div name
+	DivIpFlexio1    Clock = (offCDCDR & 0xFF) | (CCM_CDCDR_FLEXIO1_CLK_PODF_Pos << 8) | (((CCM_CDCDR_FLEXIO1_CLK_PODF_Msk >> CCM_CDCDR_FLEXIO1_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)     // flexio1 div name
+	DivIpLpi2c      Clock = (offCSCDR2 & 0xFF) | (CCM_CSCDR2_LPI2C_CLK_PODF_Pos << 8) | (((CCM_CSCDR2_LPI2C_CLK_PODF_Msk >> CCM_CSCDR2_LPI2C_CLK_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)       // lpi2c div name
+	DivIpLcdifPre   Clock = (offCSCDR2 & 0xFF) | (CCM_CSCDR2_LCDIF_PRED_Pos << 8) | (((CCM_CSCDR2_LCDIF_PRED_Msk >> CCM_CSCDR2_LCDIF_PRED_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                   // lcdif pre div name
+	DivIpCsi        Clock = (offCSCDR3 & 0xFF) | (CCM_CSCDR3_CSI_PODF_Pos << 8) | (((CCM_CSCDR3_CSI_PODF_Msk >> CCM_CSCDR3_CSI_PODF_Pos) & 0x1FFF) << 13) | (noBusyWait << 26)                         // csi div name
+)
+
+// Selected clock offsets
+const (
+	offCCSR   = 0x0C
+	offCBCDR  = 0x14
+	offCBCMR  = 0x18
+	offCSCMR1 = 0x1C
+	offCSCMR2 = 0x20
+	offCSCDR1 = 0x24
+	offCDCDR  = 0x30
+	offCSCDR2 = 0x38
+	offCSCDR3 = 0x3C
+	offCACRR  = 0x10
+	offCS1CDR = 0x28
+	offCS2CDR = 0x2C
+
+	offPllArm   = 0x00
+	offPllSys   = 0x30
+	offPllUsb1  = 0x10
+	offPllAudio = 0x70
+	offPllVideo = 0xA0
+	offPllEnet  = 0xE0
+	offPllUsb2  = 0x20
+
+	noBusyWait = 0x20
+)
+
+// analog PLL definition
+const (
+	pllBypassPos       = 16
+	pllBypassClkSrcMsk = 0xC000
+	pllBypassClkSrcPos = 14
+)
+
+// PLL clock source, bypass cloco source also
+const (
+	pllSrc24M   = 0 // Pll clock source 24M
+	pllSrcClkPN = 1 // Pll clock source CLK1_P and CLK1_N
+)
+
+const (
+	clockNotNeeded     uint32 = 0 // Clock is off during all modes
+	clockNeededRun     uint32 = 1 // Clock is on in run mode, but off in WAIT and STOP modes
+	clockNeededRunWait uint32 = 3 // Clock is on during all modes, except STOP mode
+)
+
+// getGate returns the CCM clock gating register for the receiver clk.
+func (clk Clock) getGate() *volatile.Register32 {
+	switch clk >> 8 {
+	case 0:
+		return &CCM.CCGR0
+	case 1:
+		return &CCM.CCGR1
+	case 2:
+		return &CCM.CCGR2
+	case 3:
+		return &CCM.CCGR3
+	case 4:
+		return &CCM.CCGR4
+	case 5:
+		return &CCM.CCGR5
+	case 6:
+		return &CCM.CCGR6
+	case 7:
+		return &CCM.CCGR7
+	default:
+		panic("nxp: invalid clock")
+	}
+}
+
+// setGate enables or disables the receiver clk using its gating register.
+func (clk Clock) setGate(value uint32) {
+	reg := clk.getGate()
+	shift := clk & 0x1F
+	reg.Set((reg.Get() & ^(3 << shift)) | (value << shift))
+}
+
+func (clk Clock) setCcm(value uint32) {
+	const ccmBase = 0x400fc000
+	reg := (*volatile.Register32)(unsafe.Pointer(uintptr(ccmBase + (uint32(clk) & 0xFF))))
+	msk := ((uint32(clk) >> 13) & 0x1FFF) << ((uint32(clk) >> 8) & 0x1F)
+	pos := (uint32(clk) >> 8) & 0x1F
+	bsy := (uint32(clk) >> 26) & 0x3F
+	reg.Set((reg.Get() & ^uint32(msk)) | ((value << pos) & msk))
+	if bsy < noBusyWait {
+		for CCM.CDHIPR.HasBits(1 << bsy) {
+		}
+	}
+}
+
+func setSysPfd(value ...uint32) {
+	for i, val := range value {
+		pfd528 := CCM_ANALOG.PFD_528.Get() &
+			^((CCM_ANALOG_PFD_528_PFD0_CLKGATE_Msk | CCM_ANALOG_PFD_528_PFD0_FRAC_Msk) << (8 * uint32(i)))
+		frac := (val << CCM_ANALOG_PFD_528_PFD0_FRAC_Pos) & CCM_ANALOG_PFD_528_PFD0_FRAC_Msk
+		// disable the clock output first
+		CCM_ANALOG.PFD_528.Set(pfd528 | (CCM_ANALOG_PFD_528_PFD0_CLKGATE_Msk << (8 * uint32(i))))
+		// set the new value and enable output
+		CCM_ANALOG.PFD_528.Set(pfd528 | (frac << (8 * uint32(i))))
+	}
+}
+
+func setUsb1Pfd(value ...uint32) {
+	for i, val := range value {
+		pfd480 := CCM_ANALOG.PFD_480.Get() &
+			^((CCM_ANALOG_PFD_480_PFD0_CLKGATE_Msk | CCM_ANALOG_PFD_480_PFD0_FRAC_Msk) << (8 * uint32(i)))
+		frac := (val << CCM_ANALOG_PFD_480_PFD0_FRAC_Pos) & CCM_ANALOG_PFD_480_PFD0_FRAC_Msk
+		// disable the clock output first
+		CCM_ANALOG.PFD_480.Set(pfd480 | (CCM_ANALOG_PFD_480_PFD0_CLKGATE_Msk << (8 * uint32(i))))
+		// set the new value and enable output
+		CCM_ANALOG.PFD_480.Set(pfd480 | (frac << (8 * uint32(i))))
+	}
+}
+
+// PLL configuration for ARM
+type ClockConfigArmPll struct {
+	LoopDivider uint32 // PLL loop divider. Valid range for divider value: 54-108. Fout=Fin*LoopDivider/2.
+	Src         uint8  // Pll clock source, reference _clock_pll_clk_src
+}
+
+func (cfg ClockConfigArmPll) Configure() {
+
+	// bypass PLL first
+	src := (uint32(cfg.Src) << CCM_ANALOG_PLL_ARM_BYPASS_CLK_SRC_Pos) & CCM_ANALOG_PLL_ARM_BYPASS_CLK_SRC_Msk
+	CCM_ANALOG.PLL_ARM.Set(
+		(CCM_ANALOG.PLL_ARM.Get() & ^uint32(CCM_ANALOG_PLL_ARM_BYPASS_CLK_SRC_Msk)) |
+			CCM_ANALOG_PLL_ARM_BYPASS_Msk | src)
+
+	sel := (cfg.LoopDivider << CCM_ANALOG_PLL_ARM_DIV_SELECT_Pos) & CCM_ANALOG_PLL_ARM_DIV_SELECT_Msk
+	CCM_ANALOG.PLL_ARM.Set(
+		(CCM_ANALOG.PLL_ARM.Get() & ^uint32(CCM_ANALOG_PLL_ARM_DIV_SELECT_Msk|CCM_ANALOG_PLL_ARM_POWERDOWN_Msk)) |
+			CCM_ANALOG_PLL_ARM_ENABLE_Msk | sel)
+
+	for !CCM_ANALOG.PLL_ARM.HasBits(CCM_ANALOG_PLL_ARM_LOCK_Msk) {
+	}
+
+	// disable bypass
+	CCM_ANALOG.PLL_ARM.ClearBits(CCM_ANALOG_PLL_ARM_BYPASS_Msk)
+}
+
+// PLL configuration for System
+type ClockConfigSysPll struct {
+	LoopDivider uint8  // PLL loop divider. Intended to be 1 (528M): 0 - Fout=Fref*20, 1 - Fout=Fref*22
+	Numerator   uint32 // 30 bit Numerator of fractional loop divider.
+	Denominator uint32 // 30 bit Denominator of fractional loop divider
+	Src         uint8  // Pll clock source, reference _clock_pll_clk_src
+	SsStop      uint16 // Stop value to get frequency change.
+	SsEnable    uint8  // Enable spread spectrum modulation
+	SsStep      uint16 // Step value to get frequency change step.
+}
+
+func (cfg ClockConfigSysPll) Configure(pfd ...uint32) {
+
+	// bypass PLL first
+	src := (uint32(cfg.Src) << CCM_ANALOG_PLL_SYS_BYPASS_CLK_SRC_Pos) & CCM_ANALOG_PLL_SYS_BYPASS_CLK_SRC_Msk
+	CCM_ANALOG.PLL_SYS.Set(
+		(CCM_ANALOG.PLL_SYS.Get() & ^uint32(CCM_ANALOG_PLL_SYS_BYPASS_CLK_SRC_Msk)) |
+			CCM_ANALOG_PLL_SYS_BYPASS_Msk | src)
+
+	sel := (uint32(cfg.LoopDivider) << CCM_ANALOG_PLL_SYS_DIV_SELECT_Pos) & CCM_ANALOG_PLL_SYS_DIV_SELECT_Msk
+	CCM_ANALOG.PLL_SYS.Set(
+		(CCM_ANALOG.PLL_SYS.Get() & ^uint32(CCM_ANALOG_PLL_SYS_DIV_SELECT_Msk|CCM_ANALOG_PLL_SYS_POWERDOWN_Msk)) |
+			CCM_ANALOG_PLL_SYS_ENABLE_Msk | sel)
+
+	// initialize the fractional mode
+	CCM_ANALOG.PLL_SYS_NUM.Set((cfg.Numerator << CCM_ANALOG_PLL_SYS_NUM_A_Pos) & CCM_ANALOG_PLL_SYS_NUM_A_Msk)
+	CCM_ANALOG.PLL_SYS_DENOM.Set((cfg.Denominator << CCM_ANALOG_PLL_SYS_DENOM_B_Pos) & CCM_ANALOG_PLL_SYS_DENOM_B_Msk)
+
+	// initialize the spread spectrum mode
+	inc := (uint32(cfg.SsStep) << CCM_ANALOG_PLL_SYS_SS_STEP_Pos) & CCM_ANALOG_PLL_SYS_SS_STEP_Msk
+	enb := (uint32(cfg.SsEnable) << CCM_ANALOG_PLL_SYS_SS_ENABLE_Pos) & CCM_ANALOG_PLL_SYS_SS_ENABLE_Msk
+	stp := (uint32(cfg.SsStop) << CCM_ANALOG_PLL_SYS_SS_STOP_Pos) & CCM_ANALOG_PLL_SYS_SS_STOP_Msk
+	CCM_ANALOG.PLL_SYS_SS.Set(inc | enb | stp)
+
+	for !CCM_ANALOG.PLL_SYS.HasBits(CCM_ANALOG_PLL_SYS_LOCK_Msk) {
+	}
+
+	// disable bypass
+	CCM_ANALOG.PLL_SYS.ClearBits(CCM_ANALOG_PLL_SYS_BYPASS_Msk)
+
+	// update PFDs after update
+	setSysPfd(pfd...)
+}
+
+// PLL configuration for USB
+type ClockConfigUsbPll struct {
+	Instance    uint8 // USB PLL number (1 or 2)
+	LoopDivider uint8 // PLL loop divider: 0 - Fout=Fref*20, 1 - Fout=Fref*22
+	Src         uint8 // Pll clock source, reference _clock_pll_clk_src
+}
+
+func (cfg ClockConfigUsbPll) Configure(pfd ...uint32) {
+
+	switch cfg.Instance {
+	case 1:
+
+		// bypass PLL first
+		src := (uint32(cfg.Src) << CCM_ANALOG_PLL_USB1_BYPASS_CLK_SRC_Pos) & CCM_ANALOG_PLL_USB1_BYPASS_CLK_SRC_Msk
+		CCM_ANALOG.PLL_USB1.Set(
+			(CCM_ANALOG.PLL_USB1.Get() & ^uint32(CCM_ANALOG_PLL_USB1_BYPASS_CLK_SRC_Msk)) |
+				CCM_ANALOG_PLL_USB1_BYPASS_Msk | src)
+
+		sel := uint32((cfg.LoopDivider << CCM_ANALOG_PLL_USB1_DIV_SELECT_Pos) & CCM_ANALOG_PLL_USB1_DIV_SELECT_Msk)
+		CCM_ANALOG.PLL_USB1_SET.Set(
+			(CCM_ANALOG.PLL_USB1.Get() & ^uint32(CCM_ANALOG_PLL_USB1_DIV_SELECT_Msk)) |
+				CCM_ANALOG_PLL_USB1_ENABLE_Msk | CCM_ANALOG_PLL_USB1_POWER_Msk |
+				CCM_ANALOG_PLL_USB1_EN_USB_CLKS_Msk | sel)
+
+		for !CCM_ANALOG.PLL_USB1.HasBits(CCM_ANALOG_PLL_USB1_LOCK_Msk) {
+		}
+
+		// disable bypass
+		CCM_ANALOG.PLL_USB1_CLR.Set(CCM_ANALOG_PLL_USB1_BYPASS_Msk)
+
+		// update PFDs after update
+		setUsb1Pfd(pfd...)
+
+	case 2:
+		// bypass PLL first
+		src := (uint32(cfg.Src) << CCM_ANALOG_PLL_USB2_BYPASS_CLK_SRC_Pos) & CCM_ANALOG_PLL_USB2_BYPASS_CLK_SRC_Msk
+		CCM_ANALOG.PLL_USB2.Set(
+			(CCM_ANALOG.PLL_USB2.Get() & ^uint32(CCM_ANALOG_PLL_USB2_BYPASS_CLK_SRC_Msk)) |
+				CCM_ANALOG_PLL_USB2_BYPASS_Msk | src)
+
+		sel := uint32((cfg.LoopDivider << CCM_ANALOG_PLL_USB2_DIV_SELECT_Pos) & CCM_ANALOG_PLL_USB2_DIV_SELECT_Msk)
+		CCM_ANALOG.PLL_USB2.Set(
+			(CCM_ANALOG.PLL_USB2.Get() & ^uint32(CCM_ANALOG_PLL_USB2_DIV_SELECT_Msk)) |
+				CCM_ANALOG_PLL_USB2_ENABLE_Msk | CCM_ANALOG_PLL_USB2_POWER_Msk |
+				CCM_ANALOG_PLL_USB2_EN_USB_CLKS_Msk | sel)
+
+		for !CCM_ANALOG.PLL_USB2.HasBits(CCM_ANALOG_PLL_USB2_LOCK_Msk) {
+		}
+
+		// disable bypass
+		CCM_ANALOG.PLL_USB2.ClearBits(CCM_ANALOG_PLL_USB2_BYPASS_Msk)
+
+	default:
+		panic("nxp: invalid USB PLL")
+	}
+}

src/device/nxp/mimxrt1062_hardfault.go

@@ -0,0 +1,29 @@
+// Hand created file. DO NOT DELETE.
+// Hardfault aliases for definitions that have inconsistent naming (which are
+// auto-generated by gen-device-svd.go) among devices in package nxp.
+
+// +build nxp,mimxrt1062
+
+package nxp
+
+const (
+	HardFault_CFSR_IACCVIOL    = SCB_CFSR_IACCVIOL
+	HardFault_CFSR_DACCVIOL    = SCB_CFSR_DACCVIOL
+	HardFault_CFSR_MUNSTKERR   = SCB_CFSR_MUNSTKERR
+	HardFault_CFSR_MSTKERR     = SCB_CFSR_MSTKERR
+	HardFault_CFSR_MLSPERR     = SCB_CFSR_MLSPERR
+	HardFault_CFSR_IBUSERR     = SCB_CFSR_IBUSERR
+	HardFault_CFSR_PRECISERR   = SCB_CFSR_PRECISERR
+	HardFault_CFSR_IMPRECISERR = SCB_CFSR_IMPRECISERR
+	HardFault_CFSR_UNSTKERR    = SCB_CFSR_UNSTKERR
+	HardFault_CFSR_STKERR      = SCB_CFSR_STKERR
+	HardFault_CFSR_LSPERR      = SCB_CFSR_LSPERR
+	HardFault_CFSR_UNDEFINSTR  = SCB_CFSR_UNDEFINSTR
+	HardFault_CFSR_INVSTATE    = SCB_CFSR_INVSTATE
+	HardFault_CFSR_INVPC       = SCB_CFSR_INVPC
+	HardFault_CFSR_NOCP        = SCB_CFSR_NOCP
+	HardFault_CFSR_UNALIGNED   = SCB_CFSR_UNALIGNED
+	HardFault_CFSR_DIVBYZERO   = SCB_CFSR_DIVBYZERO
+	HardFault_CFSR_MMARVALID   = SCB_CFSR_MMARVALID
+	HardFault_CFSR_BFARVALID   = SCB_CFSR_BFARVALID
+)

src/device/nxp/mimxrt1062_mpu.go

@@ -0,0 +1,278 @@
+// Hand created file. DO NOT DELETE.
+// Type definitions, fields, and constants associated with the MPU peripheral
+// of the NXP MIMXRT1062.
+
+// +build nxp,mimxrt1062
+
+package nxp
+
+import (
+	"device/arm"
+	"runtime/volatile"
+	"unsafe"
+)
+
+type MPU_Type struct {
+	TYPE    volatile.Register32 // 0x000 (R/ ) - MPU Type Register
+	CTRL    volatile.Register32 // 0x004 (R/W) - MPU Control Register
+	RNR     volatile.Register32 // 0x008 (R/W) - MPU Region RNRber Register
+	RBAR    volatile.Register32 // 0x00C (R/W) - MPU Region Base Address Register
+	RASR    volatile.Register32 // 0x010 (R/W) - MPU Region Attribute and Size Register
+	RBAR_A1 volatile.Register32 // 0x014 (R/W) - MPU Alias 1 Region Base Address Register
+	RASR_A1 volatile.Register32 // 0x018 (R/W) - MPU Alias 1 Region Attribute and Size Register
+	RBAR_A2 volatile.Register32 // 0x01C (R/W) - MPU Alias 2 Region Base Address Register
+	RASR_A2 volatile.Register32 // 0x020 (R/W) - MPU Alias 2 Region Attribute and Size Register
+	RBAR_A3 volatile.Register32 // 0x024 (R/W) - MPU Alias 3 Region Base Address Register
+	RASR_A3 volatile.Register32 // 0x028 (R/W) - MPU Alias 3 Region Attribute and Size Register
+}
+
+var MPU = (*MPU_Type)(unsafe.Pointer(uintptr(0xe000ed90)))
+
+type (
+	RegionSize  uint32
+	AccessPerms uint32
+	Extension   uint32
+)
+
+// MPU Control Register Definitions
+const (
+	MPU_CTRL_PRIVDEFENA_Pos = 2                            // MPU CTRL: PRIVDEFENA Position
+	MPU_CTRL_PRIVDEFENA_Msk = 1 << MPU_CTRL_PRIVDEFENA_Pos // MPU CTRL: PRIVDEFENA Mask
+	MPU_CTRL_HFNMIENA_Pos   = 1                            // MPU CTRL: HFNMIENA Position
+	MPU_CTRL_HFNMIENA_Msk   = 1 << MPU_CTRL_HFNMIENA_Pos   // MPU CTRL: HFNMIENA Mask
+	MPU_CTRL_ENABLE_Pos     = 0                            // MPU CTRL: ENABLE Position
+	MPU_CTRL_ENABLE_Msk     = 1                            // MPU CTRL: ENABLE Mask
+)
+
+// MPU Region Base Address Register Definitions
+const (
+	MPU_RBAR_ADDR_Pos   = 5                              // MPU RBAR: ADDR Position
+	MPU_RBAR_ADDR_Msk   = 0x7FFFFFF << MPU_RBAR_ADDR_Pos // MPU RBAR: ADDR Mask
+	MPU_RBAR_VALID_Pos  = 4                              // MPU RBAR: VALID Position
+	MPU_RBAR_VALID_Msk  = 1 << MPU_RBAR_VALID_Pos        // MPU RBAR: VALID Mask
+	MPU_RBAR_REGION_Pos = 0                              // MPU RBAR: REGION Position
+	MPU_RBAR_REGION_Msk = 0xF                            // MPU RBAR: REGION Mask
+)
+
+// MPU Region Attribute and Size Register Definitions
+const (
+	MPU_RASR_ATTRS_Pos  = 16                           // MPU RASR: MPU Region Attribute field Position
+	MPU_RASR_ATTRS_Msk  = 0xFFFF << MPU_RASR_ATTRS_Pos // MPU RASR: MPU Region Attribute field Mask
+	MPU_RASR_XN_Pos     = 28                           // MPU RASR: ATTRS.XN Position
+	MPU_RASR_XN_Msk     = 1 << MPU_RASR_XN_Pos         // MPU RASR: ATTRS.XN Mask
+	MPU_RASR_AP_Pos     = 24                           // MPU RASR: ATTRS.AP Position
+	MPU_RASR_AP_Msk     = 0x7 << MPU_RASR_AP_Pos       // MPU RASR: ATTRS.AP Mask
+	MPU_RASR_TEX_Pos    = 19                           // MPU RASR: ATTRS.TEX Position
+	MPU_RASR_TEX_Msk    = 0x7 << MPU_RASR_TEX_Pos      // MPU RASR: ATTRS.TEX Mask
+	MPU_RASR_S_Pos      = 18                           // MPU RASR: ATTRS.S Position
+	MPU_RASR_S_Msk      = 1 << MPU_RASR_S_Pos          // MPU RASR: ATTRS.S Mask
+	MPU_RASR_C_Pos      = 17                           // MPU RASR: ATTRS.C Position
+	MPU_RASR_C_Msk      = 1 << MPU_RASR_C_Pos          // MPU RASR: ATTRS.C Mask
+	MPU_RASR_B_Pos      = 16                           // MPU RASR: ATTRS.B Position
+	MPU_RASR_B_Msk      = 1 << MPU_RASR_B_Pos          // MPU RASR: ATTRS.B Mask
+	MPU_RASR_SRD_Pos    = 8                            // MPU RASR: Sub-Region Disable Position
+	MPU_RASR_SRD_Msk    = 0xFF << MPU_RASR_SRD_Pos     // MPU RASR: Sub-Region Disable Mask
+	MPU_RASR_SIZE_Pos   = 1                            // MPU RASR: Region Size Field Position
+	MPU_RASR_SIZE_Msk   = 0x1F << MPU_RASR_SIZE_Pos    // MPU RASR: Region Size Field Mask
+	MPU_RASR_ENABLE_Pos = 0                            // MPU RASR: Region enable bit Position
+	MPU_RASR_ENABLE_Msk = 1                            // MPU RASR: Region enable bit Disable Mask
+)
+
+const (
+	SCB_DCISW_WAY_Pos = 30                         // SCB DCISW: Way Position
+	SCB_DCISW_WAY_Msk = 3 << SCB_DCISW_WAY_Pos     // SCB DCISW: Way Mask
+	SCB_DCISW_SET_Pos = 5                          // SCB DCISW: Set Position
+	SCB_DCISW_SET_Msk = 0x1FF << SCB_DCISW_SET_Pos // SCB DCISW: Set Mask
+)
+
+const (
+	SCB_DCCISW_WAY_Pos = 30                          // SCB DCCISW: Way Position
+	SCB_DCCISW_WAY_Msk = 3 << SCB_DCCISW_WAY_Pos     // SCB DCCISW: Way Mask
+	SCB_DCCISW_SET_Pos = 5                           // SCB DCCISW: Set Position
+	SCB_DCCISW_SET_Msk = 0x1FF << SCB_DCCISW_SET_Pos // SCB DCCISW: Set Mask
+)
+
+const (
+	RGNSZ_32B   RegionSize = 0x04 // MPU Region Size 32 Bytes
+	RGNSZ_64B   RegionSize = 0x05 // MPU Region Size 64 Bytes
+	RGNSZ_128B  RegionSize = 0x06 // MPU Region Size 128 Bytes
+	RGNSZ_256B  RegionSize = 0x07 // MPU Region Size 256 Bytes
+	RGNSZ_512B  RegionSize = 0x08 // MPU Region Size 512 Bytes
+	RGNSZ_1KB   RegionSize = 0x09 // MPU Region Size 1 KByte
+	RGNSZ_2KB   RegionSize = 0x0A // MPU Region Size 2 KBytes
+	RGNSZ_4KB   RegionSize = 0x0B // MPU Region Size 4 KBytes
+	RGNSZ_8KB   RegionSize = 0x0C // MPU Region Size 8 KBytes
+	RGNSZ_16KB  RegionSize = 0x0D // MPU Region Size 16 KBytes
+	RGNSZ_32KB  RegionSize = 0x0E // MPU Region Size 32 KBytes
+	RGNSZ_64KB  RegionSize = 0x0F // MPU Region Size 64 KBytes
+	RGNSZ_128KB RegionSize = 0x10 // MPU Region Size 128 KBytes
+	RGNSZ_256KB RegionSize = 0x11 // MPU Region Size 256 KBytes
+	RGNSZ_512KB RegionSize = 0x12 // MPU Region Size 512 KBytes
+	RGNSZ_1MB   RegionSize = 0x13 // MPU Region Size 1 MByte
+	RGNSZ_2MB   RegionSize = 0x14 // MPU Region Size 2 MBytes
+	RGNSZ_4MB   RegionSize = 0x15 // MPU Region Size 4 MBytes
+	RGNSZ_8MB   RegionSize = 0x16 // MPU Region Size 8 MBytes
+	RGNSZ_16MB  RegionSize = 0x17 // MPU Region Size 16 MBytes
+	RGNSZ_32MB  RegionSize = 0x18 // MPU Region Size 32 MBytes
+	RGNSZ_64MB  RegionSize = 0x19 // MPU Region Size 64 MBytes
+	RGNSZ_128MB RegionSize = 0x1A // MPU Region Size 128 MBytes
+	RGNSZ_256MB RegionSize = 0x1B // MPU Region Size 256 MBytes
+	RGNSZ_512MB RegionSize = 0x1C // MPU Region Size 512 MBytes
+	RGNSZ_1GB   RegionSize = 0x1D // MPU Region Size 1 GByte
+	RGNSZ_2GB   RegionSize = 0x1E // MPU Region Size 2 GBytes
+	RGNSZ_4GB   RegionSize = 0x1F // MPU Region Size 4 GBytes
+)
+
+const (
+	PERM_NONE AccessPerms = 0 // MPU Access Permission no access
+	PERM_PRIV AccessPerms = 1 // MPU Access Permission privileged access only
+	PERM_URO  AccessPerms = 2 // MPU Access Permission unprivileged access read-only
+	PERM_FULL AccessPerms = 3 // MPU Access Permission full access
+	PERM_PRO  AccessPerms = 5 // MPU Access Permission privileged access read-only
+	PERM_RO   AccessPerms = 6 // MPU Access Permission read-only access
+)
+
+const (
+	EXTN_NORMAL Extension = 0
+	EXTN_DEVICE Extension = 2
+)
+
+func (mpu *MPU_Type) Enable(enable bool) {
+	if enable {
+		mpu.CTRL.Set(MPU_CTRL_PRIVDEFENA_Msk | MPU_CTRL_ENABLE_Msk)
+		SystemControl.SHCSR.SetBits(SCB_SHCSR_MEMFAULTENA_Msk)
+		arm.AsmFull(`
+      dsb 0xF
+      isb 0xF
+    `, nil)
+		enableDcache(true)
+		enableIcache(true)
+	} else {
+		enableIcache(false)
+		enableDcache(false)
+		arm.AsmFull(`
+      dmb 0xF
+    `, nil)
+		SystemControl.SHCSR.ClearBits(SCB_SHCSR_MEMFAULTENA_Msk)
+		mpu.CTRL.ClearBits(MPU_CTRL_ENABLE_Msk)
+	}
+}
+
+// MPU Region Base Address Register value
+func (mpu *MPU_Type) SetRBAR(region uint32, baseAddress uint32) {
+	mpu.RBAR.Set((baseAddress & MPU_RBAR_ADDR_Msk) |
+		(region & MPU_RBAR_REGION_Msk) | MPU_RBAR_VALID_Msk)
+}
+
+// MPU Region Attribute and Size Register value
+func (mpu *MPU_Type) SetRASR(size RegionSize, access AccessPerms, ext Extension, exec, share, cache, buffer, disable bool) {
+	boolBit := func(b bool) uint32 {
+		if b {
+			return 1
+		}
+		return 0
+	}
+	attr := ((uint32(ext) << MPU_RASR_TEX_Pos) & MPU_RASR_TEX_Msk) |
+		((boolBit(share) << MPU_RASR_S_Pos) & MPU_RASR_S_Msk) |
+		((boolBit(cache) << MPU_RASR_C_Pos) & MPU_RASR_C_Msk) |
+		((boolBit(buffer) << MPU_RASR_B_Pos) & MPU_RASR_B_Msk)
+	mpu.RASR.Set(((boolBit(!exec) << MPU_RASR_XN_Pos) & MPU_RASR_XN_Msk) |
+		((uint32(access) << MPU_RASR_AP_Pos) & MPU_RASR_AP_Msk) |
+		(attr & (MPU_RASR_TEX_Msk | MPU_RASR_S_Msk | MPU_RASR_C_Msk | MPU_RASR_B_Msk)) |
+		((boolBit(disable) << MPU_RASR_SRD_Pos) & MPU_RASR_SRD_Msk) |
+		((uint32(size) << MPU_RASR_SIZE_Pos) & MPU_RASR_SIZE_Msk) |
+		MPU_RASR_ENABLE_Msk)
+}
+
+func enableIcache(enable bool) {
+	if enable != SystemControl.CCR.HasBits(SCB_CCR_IC_Msk) {
+		if enable {
+			arm.AsmFull(`
+        dsb 0xF
+        isb 0xF
+      `, nil)
+			SystemControl.ICIALLU.Set(0)
+			arm.AsmFull(`
+        dsb 0xF
+        isb 0xF
+      `, nil)
+			SystemControl.CCR.SetBits(SCB_CCR_IC_Msk)
+			arm.AsmFull(`
+        dsb 0xF
+        isb 0xF
+      `, nil)
+		} else {
+			arm.AsmFull(`
+        dsb 0xF
+        isb 0xF
+      `, nil)
+			SystemControl.CCR.ClearBits(SCB_CCR_IC_Msk)
+			SystemControl.ICIALLU.Set(0)
+			arm.AsmFull(`
+        dsb 0xF
+        isb 0xF
+      `, nil)
+		}
+	}
+}
+
+func enableDcache(enable bool) {
+	if enable != SystemControl.CCR.HasBits(SCB_CCR_DC_Msk) {
+		if enable {
+			SystemControl.CSSELR.Set(0)
+			arm.AsmFull(`
+        dsb 0xF
+      `, nil)
+			ccsidr := SystemControl.CCSIDR.Get()
+			sets := (ccsidr & SCB_CCSIDR_NUMSETS_Msk) >> SCB_CCSIDR_NUMSETS_Pos
+			for sets != 0 {
+				ways := (ccsidr & SCB_CCSIDR_ASSOCIATIVITY_Msk) >> SCB_CCSIDR_ASSOCIATIVITY_Pos
+				for ways != 0 {
+					SystemControl.DCISW.Set(
+						((sets << SCB_DCISW_SET_Pos) & SCB_DCISW_SET_Msk) |
+							((ways << SCB_DCISW_WAY_Pos) & SCB_DCISW_WAY_Msk))
+					ways--
+				}
+				sets--
+			}
+			arm.AsmFull(`
+        dsb 0xF
+      `, nil)
+			SystemControl.CCR.SetBits(SCB_CCR_DC_Msk)
+			arm.AsmFull(`
+        dsb 0xF
+        isb 0xF
+      `, nil)
+		} else {
+			var (
+				ccsidr volatile.Register32
+				sets   volatile.Register32
+				ways   volatile.Register32
+			)
+			SystemControl.CSSELR.Set(0)
+			arm.AsmFull(`
+        dsb 0xF
+      `, nil)
+			SystemControl.CCR.ClearBits(SCB_CCR_DC_Msk)
+			arm.AsmFull(`
+        dsb 0xF
+      `, nil)
+			ccsidr.Set(SystemControl.CCSIDR.Get())
+			sets.Set((ccsidr.Get() & SCB_CCSIDR_NUMSETS_Msk) >> SCB_CCSIDR_NUMSETS_Pos)
+			for sets.Get() != 0 {
+				ways.Set((ccsidr.Get() & SCB_CCSIDR_ASSOCIATIVITY_Msk) >> SCB_CCSIDR_ASSOCIATIVITY_Pos)
+				for ways.Get() != 0 {
+					SystemControl.DCCISW.Set(
+						((sets.Get() << SCB_DCCISW_SET_Pos) & SCB_DCCISW_SET_Msk) |
+							((ways.Get() << SCB_DCCISW_WAY_Pos) & SCB_DCCISW_WAY_Msk))
+					ways.Set(ways.Get() - 1)
+				}
+				sets.Set(sets.Get() - 1)
+			}
+			arm.AsmFull(`
+        dsb 0xF
+        isb 0xF
+      `, nil)
+		}
+	}
+}

src/device/sam/atsamd51x-bitfields.go

@@ -0,0 +1,71 @@
+// Hand created file. DO NOT DELETE.
+// atsamd51x bitfield definitions that are not auto-generated by gen-device-svd.go
+
+// +build sam,atsamd51
+
+// These are the supported pchctrl function numberings on the atsamd51x
+// See http://ww1.microchip.com/downloads/en/DeviceDoc/SAM_D5xE5x_Family_Data_Sheet_DS60001507F.pdf
+// table 14-9
+
+package sam
+
+const (
+	PCHCTRL_GCLK_OSCCTRL_DFLL48     = 0 // DFLL48 input clock source
+	PCHCTRL_GCLK_OSCCTRL_FDPLL0     = 1 // Reference clock for FDPLL0
+	PCHCTRL_GCLK_OSCCTRL_FDPLL1     = 2 // Reference clock for FDPLL1
+	PCHCTRL_GCLK_OSCCTRL_FDPLL0_32K = 3 // FDPLL0 = 3 // 32KHz clock for internal lock timer
+	PCHCTRL_GCLK_OSCCTRL_FDPLL1_32K = 3 // FDPLL1 = 3 // 32KHz clock for internal lock timer
+	PCHCTRL_GCLK_SDHC0_SLOW         = 3 // SDHC0 = 3 // Slow
+	PCHCTRL_GCLK_SDHC1_SLOW         = 3 // SDHC1 = 3 // Slow
+	PCHCTRL_GCLK_SERCOMX_SLOW       = 3 // GCLK_SERCOM[0..7]_SLOW = 3
+	PCHCTRL_GCLK_EIC                = 4
+	PCHCTRL_GCLK_FREQM_MSR          = 5 // FREQM Measure
+	PCHCTRL_GCLK_FREQM_REF          = 6 // FREQM Reference
+	PCHCTRL_GCLK_SERCOM0_CORE       = 7 // SERCOM0 Core
+	PCHCTRL_GCLK_SERCOM1_CORE       = 8 // SERCOM1 Core
+	PCHCTRL_GCLK_TC0                = 9
+	PCHCTRL_GCLK_TC1                = 9  // TC0, TC1
+	PCHCTRL_GCLK_USB                = 10 // USB
+	PCHCTRL_GCLK_EVSYS0             = 11
+	PCHCTRL_GCLK_EVSYS1             = 12
+	PCHCTRL_GCLK_EVSYS2             = 13
+	PCHCTRL_GCLK_EVSYS3             = 14
+	PCHCTRL_GCLK_EVSYS4             = 15
+	PCHCTRL_GCLK_EVSYS5             = 16
+	PCHCTRL_GCLK_EVSYS6             = 17
+	PCHCTRL_GCLK_EVSYS7             = 18
+	PCHCTRL_GCLK_EVSYS8             = 19
+	PCHCTRL_GCLK_EVSYS9             = 20
+	PCHCTRL_GCLK_EVSYS10            = 21
+	PCHCTRL_GCLK_EVSYS11            = 22
+	PCHCTRL_GCLK_SERCOM2_CORE       = 23 // SERCOM2 Core
+	PCHCTRL_GCLK_SERCOM3_CORE       = 24 // SERCOM3 Core
+	PCHCTRL_GCLK_TCC0               = 25
+	PCHCTRL_GCLK_TCC1               = 25 // TCC0, TCC1
+	PCHCTRL_GCLK_TC2                = 26
+	PCHCTRL_GCLK_TC3                = 26 // TC2, TC3
+	PCHCTRL_GCLK_CAN0               = 27 // CAN0
+	PCHCTRL_GCLK_CAN1               = 28 // CAN1
+	PCHCTRL_GCLK_TCC2               = 29
+	PCHCTRL_GCLK_TCC3               = 29 // TCC2, TCC3
+	PCHCTRL_GCLK_TC4                = 30
+	PCHCTRL_GCLK_TC5                = 30 // TC4, TC5
+	PCHCTRL_GCLK_PDEC               = 31 // PDEC
+	PCHCTRL_GCLK_AC                 = 32 // AC
+	PCHCTRL_GCLK_CCL                = 33 // CCL
+	PCHCTRL_GCLK_SERCOM4_CORE       = 34 // SERCOM4 Core
+	PCHCTRL_GCLK_SERCOM5_CORE       = 35 // SERCOM5 Core
+	PCHCTRL_GCLK_SERCOM6_CORE       = 36 // SERCOM6 Core
+	PCHCTRL_GCLK_SERCOM7_CORE       = 37 // SERCOM7 Core
+	PCHCTRL_GCLK_TCC4               = 38 // TCC4
+	PCHCTRL_GCLK_TC6                = 39
+	PCHCTRL_GCLK_TC7                = 39 // TC6, TC7
+	PCHCTRL_GCLK_ADC0               = 40 // ADC0
+	PCHCTRL_GCLK_ADC1               = 41 // ADC1
+	PCHCTRL_GCLK_DAC                = 42 // DAC
+	PCHCTRL_GCLK_I2S0               = 43
+	PCHCTRL_GCLK_I2S1               = 44
+	PCHCTRL_GCLK_SDHC0              = 45 // SDHC0
+	PCHCTRL_GCLK_SDHC1              = 46 // SDHC1
+	PCHCTRL_GCLK_CM4_TRACE          = 47 // CM4 Trace
+)

src/device/stm32/stm32f4-altfunc-bitfields.go

@@ -1,7 +1,9 @@
-// These are the supported alternate function numberings on the stm32f407
-// +build stm32,stm32f407
+// Hand created file. DO NOT DELETE.
+// STM32FXXX (except stm32f1xx) bitfield definitions that are not
+//  auto-generated by gen-device-svd.go
+// +build stm32f4
 
-// Alternate function settings on the stm32f4xx series
+// Alternate function settings on the stm32f4 series
 
 package stm32
 

src/examples/pwm/pwm.go

@@ -8,7 +8,7 @@ import (
 // This example assumes that an RGB LED is connected to pins 3, 5 and 6 on an Arduino.
 // Change the values below to use different pins.
 const (
-	redPin   = machine.D3
+	redPin   = machine.D4
 	greenPin = machine.D5
 	bluePin  = machine.D6
 )

src/internal/bytealg/bytealg.go

@@ -124,3 +124,130 @@ func IndexString(str, sub string) int {
 	}
 	return -1
 }
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The following code has been copied from the Go 1.15 release tree.
+
+// PrimeRK is the prime base used in Rabin-Karp algorithm.
+const PrimeRK = 16777619
+
+// HashStrBytes returns the hash and the appropriate multiplicative
+// factor for use in Rabin-Karp algorithm.
+func HashStrBytes(sep []byte) (uint32, uint32) {
+	hash := uint32(0)
+	for i := 0; i < len(sep); i++ {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStr returns the hash and the appropriate multiplicative
+// factor for use in Rabin-Karp algorithm.
+func HashStr(sep string) (uint32, uint32) {
+	hash := uint32(0)
+	for i := 0; i < len(sep); i++ {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStrRevBytes returns the hash of the reverse of sep and the
+// appropriate multiplicative factor for use in Rabin-Karp algorithm.
+func HashStrRevBytes(sep []byte) (uint32, uint32) {
+	hash := uint32(0)
+	for i := len(sep) - 1; i >= 0; i-- {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStrRev returns the hash of the reverse of sep and the
+// appropriate multiplicative factor for use in Rabin-Karp algorithm.
+func HashStrRev(sep string) (uint32, uint32) {
+	hash := uint32(0)
+	for i := len(sep) - 1; i >= 0; i-- {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// IndexRabinKarpBytes uses the Rabin-Karp search algorithm to return the index of the
+// first occurence of substr in s, or -1 if not present.
+func IndexRabinKarpBytes(s, sep []byte) int {
+	// Rabin-Karp search
+	hashsep, pow := HashStrBytes(sep)
+	n := len(sep)
+	var h uint32
+	for i := 0; i < n; i++ {
+		h = h*PrimeRK + uint32(s[i])
+	}
+	if h == hashsep && Equal(s[:n], sep) {
+		return 0
+	}
+	for i := n; i < len(s); {
+		h *= PrimeRK
+		h += uint32(s[i])
+		h -= pow * uint32(s[i-n])
+		i++
+		if h == hashsep && Equal(s[i-n:i], sep) {
+			return i - n
+		}
+	}
+	return -1
+}
+
+// IndexRabinKarp uses the Rabin-Karp search algorithm to return the index of the
+// first occurence of substr in s, or -1 if not present.
+func IndexRabinKarp(s, substr string) int {
+	// Rabin-Karp search
+	hashss, pow := HashStr(substr)
+	n := len(substr)
+	var h uint32
+	for i := 0; i < n; i++ {
+		h = h*PrimeRK + uint32(s[i])
+	}
+	if h == hashss && s[:n] == substr {
+		return 0
+	}
+	for i := n; i < len(s); {
+		h *= PrimeRK
+		h += uint32(s[i])
+		h -= pow * uint32(s[i-n])
+		i++
+		if h == hashss && s[i-n:i] == substr {
+			return i - n
+		}
+	}
+	return -1
+}

src/internal/task/task.go

@@ -18,3 +18,8 @@ type Task struct {
 	// state is the underlying running state of the task.
 	state state
 }
+
+// getGoroutineStackSize is a compiler intrinsic that returns the stack size for
+// the given function and falls back to the default stack size. It is replaced
+// with a load from a special section just before codegen.
+func getGoroutineStackSize(fn uintptr) uintptr

src/internal/task/task_coroutine.go

@@ -67,7 +67,7 @@ func createTask() *Task {
 // start invokes a function in a new goroutine. Calls to this are inserted by the compiler.
 // The created goroutine starts running immediately.
 // This is implemented inside the compiler.
-func start(fn uintptr, args unsafe.Pointer)
+func start(fn uintptr, args unsafe.Pointer, stackSize uintptr)
 
 // Current returns the current active task.
 // This is implemented inside the compiler.

src/internal/task/task_none.go

@@ -17,7 +17,7 @@ func Current() *Task {
 }
 
 //go:noinline
-func start(fn uintptr, args unsafe.Pointer) {
+func start(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	// The compiler will error if this is reachable.
 	runtimePanic("scheduler is disabled")
 }

src/internal/task/task_stack.go

@@ -54,7 +54,7 @@ func (t *Task) Resume() {
 }
 
 // initialize the state and prepare to call the specified function with the specified argument bundle.
-func (s *state) initialize(fn uintptr, args unsafe.Pointer) {
+func (s *state) initialize(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	// Create a stack.
 	stack := make([]uintptr, stackSize/unsafe.Sizeof(uintptr(0)))
 
@@ -67,9 +67,9 @@ func runqueuePushBack(*Task)
 
 // start creates and starts a new goroutine with the given function and arguments.
 // The new goroutine is scheduled to run later.
-func start(fn uintptr, args unsafe.Pointer) {
+func start(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	t := &Task{}
-	t.state.initialize(fn, args)
+	t.state.initialize(fn, args, stackSize)
 	runqueuePushBack(t)
 }
 

src/internal/task/task_stack_avr.go

@@ -4,8 +4,6 @@ package task
 
 import "unsafe"
 
-const stackSize = 256
-
 // calleeSavedRegs is the list of registers that must be saved and restored when
 // switching between tasks. Also see scheduler_avr.S that relies on the
 // exact layout of this struct.

src/internal/task/task_stack_cortexm.go

@@ -4,8 +4,6 @@ package task
 
 import "unsafe"
 
-const stackSize = 1024
-
 // calleeSavedRegs is the list of registers that must be saved and restored when
 // switching between tasks. Also see scheduler_cortexm.S that relies on the
 // exact layout of this struct.

src/machine/board_arduino_zero.go

@@ -0,0 +1,101 @@
+// +build sam,atsamd21,arduino_zero
+
+package machine
+
+// used to reset into bootloader
+const RESET_MAGIC_VALUE = 0x07738135
+
+// GPIO Pins - Digital Low
+const (
+	D0 = PA11 // RX
+	D1 = PA10 // TX
+	D2 = PA14
+	D3 = PA09 // PWM available
+	D4 = PA08 // PWM available
+	D5 = PA15 // PWM available
+	D6 = PA20 // PWM available
+	D7 = PA21
+)
+
+// GPIO Pins - Digital High
+const (
+	D8  = PA06 // PWM available
+	D9  = PA07 // PWM available
+	D10 = PA18 // PWM available
+	D11 = PA16 // PWM available
+	D12 = PA19 // PWM available
+	D13 = PA17 // PWM available
+)
+
+// LEDs on the Arduino Zero
+const (
+	LED      = LED1
+	LED1 Pin = D13
+	LED2 Pin = PA27 // TX LED
+	LED3 Pin = PB03 // RX LED
+)
+
+// ADC pins
+const (
+	AREF Pin = PA03
+	ADC0 Pin = PA02
+	ADC1 Pin = PB08
+	ADC2 Pin = PB09
+	ADC3 Pin = PA04
+	ADC4 Pin = PA05
+	ADC5 Pin = PB02
+)
+
+// SPI pins - EDBG connected
+const (
+	SPI0_SDO_PIN Pin = PA16 // MOSI: SERCOM1/PAD[0]
+	SPI0_SDI_PIN Pin = PA19 // MISO: SERCOM1/PAD[2]
+	SPI0_SCK_PIN Pin = PA17 // SCK:  SERCOM1/PAD[3]
+)
+
+// SPI pins (Legacy ICSP)
+const (
+	SPI1_SDO_PIN Pin = PB10 // MOSI: SERCOM4/PAD[2] - Pin 4
+	SPI1_SDI_PIN Pin = PA12 // MISO: SERCOM4/PAD[0] - Pin 1
+	SPI1_SCK_PIN Pin = PB11 // SCK:  SERCOM4/PAD[3] - Pin 3
+)
+
+// I2C pins - EDBG connected
+const (
+	SDA_PIN Pin = PA22 // SDA: SERCOM3/PAD[0] - Pin 20
+	SCL_PIN Pin = PA23 // SCL: SERCOM3/PAD[1] - Pin 21
+)
+
+// I2S pins - might not be exposed
+const (
+	I2S_SCK_PIN Pin = PA10
+	I2S_SD_PIN  Pin = PA07
+	I2S_WS_PIN  Pin = PA11
+)
+
+// UART0 pins - EDBG connected
+const (
+	UART_RX_PIN Pin = D0
+	UART_TX_PIN Pin = D1
+)
+
+// 'native' USB port pins
+const (
+	USBCDC_DM_PIN Pin = PA24
+	USBCDC_DP_PIN Pin = PA25
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "Arduino Zero"
+	usb_STRING_MANUFACTURER = "Arduino LLC"
+
+	usb_VID uint16 = 0x2341
+	usb_PID uint16 = 0x804d
+)
+
+// 32.768 KHz Crystal
+const (
+	XIN32  Pin = PA00
+	XOUT32 Pin = PA01
+)

src/machine/board_bluepill.go

@@ -65,11 +65,15 @@ var (
 		Buffer: NewRingBuffer(),
 		Bus:    stm32.USART1,
 	}
-	UART1 = &UART0
+	UART1 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    stm32.USART2,
+	}
 )
 
 func init() {
 	UART0.Interrupt = interrupt.New(stm32.IRQ_USART1, UART0.handleInterrupt)
+	UART1.Interrupt = interrupt.New(stm32.IRQ_USART2, UART1.handleInterrupt)
 }
 
 // SPI pins

src/machine/board_circuitplay_bluefruit.go

@@ -2,7 +2,7 @@
 
 package machine
 
-const HasLowFrequencyCrystal = true
+const HasLowFrequencyCrystal = false
 
 // GPIO Pins
 const (

src/machine/board_esp32-coreboard-v2.go

@@ -0,0 +1,88 @@
+// +build esp32_coreboard_v2
+
+package machine
+
+// Built-in LED on some ESP32 boards.
+const LED = IO2
+
+const (
+	CLK  Pin = 6
+	CMD  Pin = 11
+	IO0  Pin = 0
+	IO1  Pin = 1
+	IO10 Pin = 10
+	IO16 Pin = 16
+	IO17 Pin = 17
+	IO18 Pin = 18
+	IO19 Pin = 19
+	IO2  Pin = 2
+	IO21 Pin = 21
+	IO22 Pin = 22
+	IO23 Pin = 23
+	IO25 Pin = 25
+	IO26 Pin = 26
+	IO27 Pin = 27
+	IO3  Pin = 3
+	IO32 Pin = 32
+	IO33 Pin = 33
+	IO34 Pin = 34
+	IO35 Pin = 35
+	IO36 Pin = 36
+	IO39 Pin = 39
+	IO4  Pin = 4
+	IO5  Pin = 5
+	IO9  Pin = 9
+	RXD  Pin = 3
+	SD0  Pin = 7
+	SD1  Pin = 8
+	SD2  Pin = 9
+	SD3  Pin = 10
+	SVN  Pin = 39
+	SVP  Pin = 36
+	TCK  Pin = 13
+	TD0  Pin = 15
+	TDI  Pin = 12
+	TMS  Pin = 14
+	TXD  Pin = 1
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = IO18
+	SPI0_SDO_PIN = IO23
+	SPI0_SDI_PIN = IO19
+	SPI0_CS0_PIN = IO5
+)
+
+// I2C pins
+const (
+	SDA_PIN = IO21
+	SCL_PIN = IO22
+)
+
+// ADC pins
+const (
+	ADC0 Pin = IO34
+	ADC1 Pin = IO35
+	ADC2 Pin = IO36
+	ADC3 Pin = IO39
+)
+
+// UART0 pins
+const (
+	UART_TX_PIN = IO1
+	UART_RX_PIN = IO3
+)
+
+// UART1 pins
+const (
+	UART1_TX_PIN = IO9
+	UART1_RX_PIN = IO10
+)
+
+// PWM pins
+const (
+	PWM0_PIN Pin = IO2
+	PWM1_PIN Pin = IO0
+	PWM2_PIN Pin = IO4
+)

src/machine/board_feather-stm32f405.go

@@ -0,0 +1,245 @@
+// +build feather_stm32f405
+
+package machine
+
+import (
+	"device/stm32"
+	"runtime/interrupt"
+)
+
+const (
+	NUM_DIGITAL_IO_PINS = 39
+	NUM_ANALOG_IO_PINS  = 7
+)
+
+// Digital pins
+const (
+	// Arduino pin = MCU port pin // primary functions (alternate functions)
+	D0  = PB11 // USART3 RX, PWM TIM2_CH4 (I2C2 SDA)
+	D1  = PB10 // USART3 TX, PWM TIM2_CH3 (I2C2 SCL, I2S2 BCK)
+	D2  = PB3  // GPIO, SPI3 FLASH SCK
+	D3  = PB4  // GPIO, SPI3 FLASH MISO
+	D4  = PB5  // GPIO, SPI3 FLASH MOSI
+	D5  = PC7  // GPIO, PWM TIM3_CH2 (USART6 RX, I2S3 MCK)
+	D6  = PC6  // GPIO, PWM TIM3_CH1 (USART6 TX, I2S2 MCK)
+	D7  = PA15 // GPIO, SPI3 FLASH CS
+	D8  = PC0  // GPIO, Neopixel
+	D9  = PB8  // GPIO, PWM TIM4_CH3 (CAN1 RX, I2C1 SCL)
+	D10 = PB9  // GPIO, PWM TIM4_CH4 (CAN1 TX, I2C1 SDA, I2S2 WSL)
+	D11 = PC3  // GPIO (I2S2 SD, SPI2 MOSI)
+	D12 = PC2  // GPIO (I2S2ext SD, SPI2 MISO)
+	D13 = PC1  // GPIO, Builtin LED
+	D14 = PB7  // I2C1 SDA, PWM TIM4_CH2 (USART1 RX)
+	D15 = PB6  // I2C1 SCL, PWM TIM4_CH1 (USART1 TX, CAN2 TX)
+	D16 = PA4  // A0 (DAC OUT1)
+	D17 = PA5  // A1 (DAC OUT2, SPI1 SCK)
+	D18 = PA6  // A2, PWM TIM3_CH1 (SPI1 MISO)
+	D19 = PA7  // A3, PWM TIM3_CH2 (SPI1 MOSI)
+	D20 = PC4  // A4
+	D21 = PC5  // A5
+	D22 = PA3  // A6
+	D23 = PB13 // SPI2 SCK, PWM TIM1_CH1N (I2S2 BCK, CAN2 TX)
+	D24 = PB14 // SPI2 MISO, PWM TIM1_CH2N (I2S2ext SD)
+	D25 = PB15 // SPI2 MOSI, PWM TIM1_CH3N (I2S2 SD)
+	D26 = PC8  // SDIO
+	D27 = PC9  // SDIO
+	D28 = PC10 // SDIO
+	D29 = PC11 // SDIO
+	D30 = PC12 // SDIO
+	D31 = PD2  // SDIO
+	D32 = PB12 // SD Detect
+	D33 = PC14 // OSC32
+	D34 = PC15 // OSC32
+	D35 = PA11 // USB D+
+	D36 = PA12 // USB D-
+	D37 = PA13 // SWDIO
+	D38 = PA14 // SWCLK
+)
+
+// Analog pins
+const (
+	A0 = D16 // ADC12 IN4
+	A1 = D17 // ADC12 IN5
+	A2 = D18 // ADC12 IN6
+	A3 = D19 // ADC12 IN7
+	A4 = D20 // ADC12 IN14
+	A5 = D21 // ADC12 IN15
+	A6 = D22 // VBAT
+)
+
+func init() {
+	initLED()
+	initUART()
+	initSPI()
+	initI2C()
+}
+
+// -- LEDs ---------------------------------------------------------------------
+
+const (
+	NUM_BOARD_LED      = 1
+	NUM_BOARD_NEOPIXEL = 1
+
+	LED_RED      = D13
+	LED_NEOPIXEL = D8
+	LED_BUILTIN  = LED_RED
+	LED          = LED_BUILTIN
+)
+
+func initLED() {}
+
+// -- UART ---------------------------------------------------------------------
+
+const (
+	// #===========#==========#==============#============#=======#=======#
+	// | Interface | Hardware |  Bus(Freq)   | RX/TX Pins | AltFn | Alias |
+	// #===========#==========#==============#============#=======#=======#
+	// |   UART1   |  USART3  | APB1(42 MHz) |   D0/D1    |   7   |   ~   |
+	// |   UART2   |  USART6  | APB2(84 MHz) |   D5/D6    |   8   |   ~   |
+	// |   UART3   |  USART1  | APB2(84 MHz) |  D14/D15   |   7   |   ~   |
+	// | --------- | -------- | ------------ | ---------- | ----- | ----- |
+	// |   UART0   |  USART3  | APB1(42 MHz) |   D0/D1    |   7   | UART1 |
+	// #===========#==========#==============#============#=======#=======#
+	NUM_UART_INTERFACES = 3
+
+	UART1_RX_PIN = D0 // UART1 = hardware: USART3
+	UART1_TX_PIN = D1 //
+
+	UART2_RX_PIN = D5 // UART2 = hardware: USART6
+	UART2_TX_PIN = D6 //
+
+	UART3_RX_PIN = D14 // UART3 = hardware: USART1
+	UART3_TX_PIN = D15 //
+
+	UART0_RX_PIN = UART1_RX_PIN // UART0 = alias: UART1
+	UART0_TX_PIN = UART1_TX_PIN //
+
+	UART_RX_PIN = UART0_RX_PIN // default/primary UART pins
+	UART_TX_PIN = UART0_TX_PIN //
+)
+
+var (
+	UART1 = UART{
+		Buffer:          NewRingBuffer(),
+		Bus:             stm32.USART3,
+		AltFuncSelector: stm32.AF7_USART1_2_3,
+	}
+	UART2 = UART{
+		Buffer:          NewRingBuffer(),
+		Bus:             stm32.USART6,
+		AltFuncSelector: stm32.AF8_USART4_5_6,
+	}
+	UART3 = UART{
+		Buffer:          NewRingBuffer(),
+		Bus:             stm32.USART1,
+		AltFuncSelector: stm32.AF7_USART1_2_3,
+	}
+	UART0 = UART1
+)
+
+func initUART() {
+	UART1.Interrupt = interrupt.New(stm32.IRQ_USART3, UART1.handleInterrupt)
+	UART2.Interrupt = interrupt.New(stm32.IRQ_USART6, UART2.handleInterrupt)
+	UART3.Interrupt = interrupt.New(stm32.IRQ_USART1, UART3.handleInterrupt)
+}
+
+// -- SPI ----------------------------------------------------------------------
+
+const (
+	// #===========#==========#==============#==================#=======#=======#
+	// | Interface | Hardware |  Bus(Freq)   | SCK/SDI/SDO Pins | AltFn | Alias |
+	// #===========#==========#==============#==================#=======#=======#
+	// |   SPI1    |   SPI2   | APB1(42 MHz) |    D23/D24/D25   |   5   |   ~   |
+	// |   SPI2    |   SPI3   | APB1(42 MHz) |     D2/D3/D4     |   6   |   ~   |
+	// |   SPI3    |   SPI1   | APB2(84 MHz) |    D17/D18/D19   |   5   |   ~   |
+	// | --------- | -------- | ------------ | ---------------- | ----- | ----- |
+	// |   SPI0    |   SPI2   | APB1(42 MHz) |    D23/D24/D25   |   5   | SPI1  |
+	// #===========#==========#==============#==================#=======#=======#
+	NUM_SPI_INTERFACES = 3
+
+	SPI1_SCK_PIN = D23 //
+	SPI1_SDI_PIN = D24 // SPI1 = hardware: SPI2
+	SPI1_SDO_PIN = D25 //
+
+	SPI2_SCK_PIN = D2 //
+	SPI2_SDI_PIN = D3 // SPI2 = hardware: SPI3
+	SPI2_SDO_PIN = D4 //
+
+	SPI3_SCK_PIN = D17 //
+	SPI3_SDI_PIN = D18 // SPI3 = hardware: SPI1
+	SPI3_SDO_PIN = D19 //
+
+	SPI0_SCK_PIN = SPI1_SCK_PIN //
+	SPI0_SDI_PIN = SPI1_SDI_PIN // SPI0 = alias: SPI1
+	SPI0_SDO_PIN = SPI1_SDO_PIN //
+
+	SPI_SCK_PIN = SPI0_SCK_PIN //
+	SPI_SDI_PIN = SPI0_SDI_PIN // default/primary SPI pins
+	SPI_SDO_PIN = SPI0_SDO_PIN //
+)
+
+var (
+	SPI1 = SPI{
+		Bus:             stm32.SPI2,
+		AltFuncSelector: stm32.AF5_SPI1_SPI2,
+	}
+	SPI2 = SPI{
+		Bus:             stm32.SPI3,
+		AltFuncSelector: stm32.AF6_SPI3,
+	}
+	SPI3 = SPI{
+		Bus:             stm32.SPI1,
+		AltFuncSelector: stm32.AF5_SPI1_SPI2,
+	}
+	SPI0 = SPI1
+)
+
+func initSPI() {}
+
+// -- I2C ----------------------------------------------------------------------
+
+const (
+	// #===========#==========#==============#==============#=======#=======#
+	// | Interface | Hardware |  Bus(Freq)   | SDA/SCL Pins | AltFn | Alias |
+	// #===========#==========#==============#==============#=======#=======#
+	// |   I2C1    |   I2C1   | APB1(42 MHz) |   D14/D15    |   4   |   ~   |
+	// |   I2C2    |   I2C2   | APB1(42 MHz) |    D0/D1     |   4   |   ~   |
+	// |   I2C3    |   I2C1   | APB1(42 MHz) |    D9/D10    |   4   |   ~   |
+	// | --------- | -------- | ------------ | ------------ | ----- | ----- |
+	// |   I2C0    |   I2C1   | APB1(42 MHz) |   D14/D15    |   4   | I2C1  |
+	// #===========#==========#==============#==============#=======#=======#
+	NUM_I2C_INTERFACES = 3
+
+	I2C1_SDA_PIN = D14 // I2C1 = hardware: I2C1
+	I2C1_SCL_PIN = D15 //
+
+	I2C2_SDA_PIN = D0 // I2C2 = hardware: I2C2
+	I2C2_SCL_PIN = D1 //
+
+	I2C3_SDA_PIN = D9  // I2C3 = hardware: I2C1
+	I2C3_SCL_PIN = D10 //   (interface duplicated on second pair of pins)
+
+	I2C0_SDA_PIN = I2C1_SDA_PIN // I2C0 = alias: I2C1
+	I2C0_SCL_PIN = I2C1_SCL_PIN //
+
+	I2C_SDA_PIN = I2C0_SDA_PIN // default/primary I2C pins
+	I2C_SCL_PIN = I2C0_SCL_PIN //
+)
+
+var (
+	I2C1 = I2C{
+		Bus:             stm32.I2C1,
+		AltFuncSelector: stm32.AF4_I2C1_2_3,
+	}
+	I2C2 = I2C{
+		Bus:             stm32.I2C2,
+		AltFuncSelector: stm32.AF4_I2C1_2_3,
+	}
+	I2C3 = I2C{
+		Bus:             stm32.I2C1,
+		AltFuncSelector: stm32.AF4_I2C1_2_3,
+	}
+	I2C0 = I2C1
+)
+
+func initI2C() {}

src/machine/board_itsybitsy-nrf52840.go

@@ -0,0 +1,100 @@
+// +build itsybitsy_nrf52840
+
+package machine
+
+const HasLowFrequencyCrystal = true
+
+// GPIO Pins
+const (
+	D0  = P0_25 // UART TX
+	D1  = P0_24 // UART RX
+	D2  = P1_02
+	D3  = P0_06 // LED1
+	D4  = P0_29 // Button
+	D5  = P0_27
+	D6  = P1_09 // DotStar Clock
+	D7  = P1_08
+	D8  = P0_08 // DotStar Data
+	D9  = P0_07
+	D10 = P0_05
+	D11 = P0_26
+	D12 = P0_11
+	D13 = P0_12
+	D14 = P0_04 // A0
+	D15 = P0_30 // A1
+	D16 = P0_28 // A2
+	D17 = P0_31 // A3
+	D18 = P0_02 // A4
+	D19 = P0_03 // A5
+	D20 = P0_05 // A6
+	D21 = P0_16 // I2C SDA
+	D22 = P0_14 // I2C SCL
+	D23 = P0_20 // SPI SDI
+	D24 = P0_15 // SPI SDO
+	D25 = P0_13 // SPI SCK
+	D26 = P0_19 // QSPI SCK
+	D27 = P0_23 // QSPI CS
+	D28 = P0_21 // QSPI Data 0
+	D29 = P0_22 // QSPI Data 1
+	D30 = P1_00 // QSPI Data 2
+	D31 = P0_17 // QSPI Data 3
+)
+
+// Analog Pins
+const (
+	A0 = D14
+	A1 = D15
+	A2 = D16
+	A3 = D17
+	A4 = D18
+	A5 = D19
+	A6 = D20
+)
+
+const (
+	LED    = D3
+	LED1   = LED
+	BUTTON = D4
+
+	QSPI_SCK   = D26
+	QSPI_CS    = D27
+	QSPI_DATA0 = D28
+	QSPI_DATA1 = D29
+	QSPI_DATA2 = D30
+	QSPI_DATA3 = D31
+)
+
+// UART0 pins (logical UART1)
+const (
+	UART_RX_PIN = D0
+	UART_TX_PIN = D1
+)
+
+// UART0 is the USB device
+var (
+	UART0 = USB
+)
+
+// I2C pins
+const (
+	SDA_PIN = D21 // I2C0 external
+	SCL_PIN = D22 // I2C0 external
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = D25
+	SPI0_SDO_PIN = D24
+	SPI0_SDI_PIN = D23
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "Adafruit ItsyBitsy nRF52840 Express"
+	usb_STRING_MANUFACTURER = "Adafruit"
+)
+
+var (
+	usb_VID uint16 = 0x239A
+	usb_PID uint16 = 0x8051
+)

src/machine/board_nodemcu.go

@@ -0,0 +1,35 @@
+// +build nodemcu
+
+// Pinout for the NodeMCU dev kit.
+
+package machine
+
+// GPIO pins on the NodeMCU board.
+const (
+	D0 Pin = 16
+	D1 Pin = 5
+	D2 Pin = 4
+	D3 Pin = 0
+	D4 Pin = 2
+	D5 Pin = 14
+	D6 Pin = 12
+	D7 Pin = 13
+	D8 Pin = 15
+)
+
+// Onboard blue LED (on the AI-Thinker module).
+const LED = D4
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = D5
+	SPI0_SDO_PIN = D7
+	SPI0_SDI_PIN = D6
+	SPI0_CS0_PIN = D8
+)
+
+// I2C pins
+const (
+	SDA_PIN = D2
+	SCL_PIN = D1
+)

src/machine/board_qtpy.go

@@ -0,0 +1,118 @@
+// +build sam,atsamd21,qtpy
+
+package machine
+
+import (
+	"device/sam"
+	"runtime/interrupt"
+)
+
+// used to reset into bootloader
+const RESET_MAGIC_VALUE = 0xf01669ef
+
+// GPIO Pins
+const (
+	D0  = PA02 // PWM available
+	D1  = PA03
+	D2  = PA04 // PWM available
+	D3  = PA05 // PWM available
+	D4  = PA16 // PWM available
+	D5  = PA17 // PWM available
+	D6  = PA06
+	D7  = PA07
+	D8  = PA11
+	D9  = PA09
+	D10 = PA10
+	D11 = PA18
+	D12 = PA15
+	D13 = PA27
+	D14 = PA23
+	D15 = PA19
+	D16 = PA22
+	D17 = PA08
+)
+
+// Analog pins
+const (
+	A0 = D1
+	A1 = D1
+	A2 = D2
+	A3 = D3
+	A4 = D4
+)
+
+const (
+	LED = D13
+)
+
+// UART0 aka USBCDC pins
+const (
+	USBCDC_DM_PIN = PA24
+	USBCDC_DP_PIN = PA25
+)
+
+// UART1 pins
+const (
+	UART_TX_PIN = D6
+	UART_RX_PIN = D7
+)
+
+// UART1 on the QT Py M0.
+var (
+	UART1 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM0_USART,
+		SERCOM: 0,
+	}
+)
+
+func init() {
+	UART1.Interrupt = interrupt.New(sam.IRQ_SERCOM0, UART1.handleInterrupt)
+}
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = D8
+	SPI0_SDO_PIN = D10
+	SPI0_SDI_PIN = D9
+)
+
+// SPI on the QT Py M0.
+var (
+	SPI0 = SPI{
+		Bus:    sam.SERCOM0_SPI,
+		SERCOM: 0,
+	}
+)
+
+// I2C pins
+const (
+	SDA_PIN = D4 // SDA
+	SCL_PIN = D5 // SCL
+)
+
+// I2C on the QT Py M0.
+var (
+	I2C0 = I2C{
+		Bus:    sam.SERCOM2_I2CM,
+		SERCOM: 2,
+	}
+)
+
+// I2S pins
+const (
+	I2S_SCK_PIN = PA10
+	I2S_SD_PIN  = PA08
+	I2S_WS_PIN  = NoPin // TODO: figure out what this is on QT Py M0.
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "Adafruit QTPy M0"
+	usb_STRING_MANUFACTURER = "Adafruit"
+)
+
+var (
+	usb_VID uint16 = 0x239A
+	usb_PID uint16 = 0x80CB
+)

src/machine/board_stm32.go

@@ -1,16 +1,5 @@
-// +build bluepill nucleof103rb stm32f4disco
+// +build bluepill nucleof103rb stm32f4
 
 package machine
 
 // Peripheral abstraction layer for the stm32.
-
-const (
-	portA Pin = iota * 16
-	portB
-	portC
-	portD
-	portE
-	portF
-	portG
-	portH
-)

src/machine/board_stm32f4disco.go

@@ -7,96 +7,6 @@ import (
 	"runtime/interrupt"
 )
 
-const (
-	PA0  = portA + 0
-	PA1  = portA + 1
-	PA2  = portA + 2
-	PA3  = portA + 3
-	PA4  = portA + 4
-	PA5  = portA + 5
-	PA6  = portA + 6
-	PA7  = portA + 7
-	PA8  = portA + 8
-	PA9  = portA + 9
-	PA10 = portA + 10
-	PA11 = portA + 11
-	PA12 = portA + 12
-	PA13 = portA + 13
-	PA14 = portA + 14
-	PA15 = portA + 15
-
-	PB0  = portB + 0
-	PB1  = portB + 1
-	PB2  = portB + 2
-	PB3  = portB + 3
-	PB4  = portB + 4
-	PB5  = portB + 5
-	PB6  = portB + 6
-	PB7  = portB + 7
-	PB8  = portB + 8
-	PB9  = portB + 9
-	PB10 = portB + 10
-	PB11 = portB + 11
-	PB12 = portB + 12
-	PB13 = portB + 13
-	PB14 = portB + 14
-	PB15 = portB + 15
-
-	PC0  = portC + 0
-	PC1  = portC + 1
-	PC2  = portC + 2
-	PC3  = portC + 3
-	PC4  = portC + 4
-	PC5  = portC + 5
-	PC6  = portC + 6
-	PC7  = portC + 7
-	PC8  = portC + 8
-	PC9  = portC + 9
-	PC10 = portC + 10
-	PC11 = portC + 11
-	PC12 = portC + 12
-	PC13 = portC + 13
-	PC14 = portC + 14
-	PC15 = portC + 15
-
-	PD0  = portD + 0
-	PD1  = portD + 1
-	PD2  = portD + 2
-	PD3  = portD + 3
-	PD4  = portD + 4
-	PD5  = portD + 5
-	PD6  = portD + 6
-	PD7  = portD + 7
-	PD8  = portD + 8
-	PD9  = portD + 9
-	PD10 = portD + 10
-	PD11 = portD + 11
-	PD12 = portD + 12
-	PD13 = portD + 13
-	PD14 = portD + 14
-	PD15 = portD + 15
-
-	PE0  = portE + 0
-	PE1  = portE + 1
-	PE2  = portE + 2
-	PE3  = portE + 3
-	PE4  = portE + 4
-	PE5  = portE + 5
-	PE6  = portE + 6
-	PE7  = portE + 7
-	PE8  = portE + 8
-	PE9  = portE + 9
-	PE10 = portE + 10
-	PE11 = portE + 11
-	PE12 = portE + 12
-	PE13 = portE + 13
-	PE14 = portE + 14
-	PE15 = portE + 15
-
-	PH0 = portH + 0
-	PH1 = portH + 1
-)
-
 const (
 	LED         = LED_BUILTIN
 	LED1        = LED_GREEN

src/machine/board_teensy40.go

@@ -0,0 +1,262 @@
+// +build teensy40
+
+package machine
+
+import (
+	"device/nxp"
+	"runtime/interrupt"
+)
+
+// Digital pins
+const (
+	//  = Pin  // [Pad]:       Alt Func 0       Alt Func 1       Alt Func 2       Alt Func 3      Alt Func 4            Alt Func 5  Alt Func 6            Alt Func 7             Alt Func 8             Alt Func 9
+	//  = ----    -----------  ---------------  ---------------  ---------------  --------------  --------------------  ----------  --------------------  ---------------------  ---------------------  ----------------
+	D0  = PA3  // [AD_B0_03]:  FLEXCAN2_RX      XBAR1_INOUT17    LPUART6_RX       USB_OTG1_OC     FLEXPWM1_PWMX01       GPIO1_IO03  REF_CLK_24M           LPSPI3_PCS0             ~                      ~
+	D1  = PA2  // [AD_B0_02]:  FLEXCAN2_TX      XBAR1_INOUT16    LPUART6_TX       USB_OTG1_PWR    FLEXPWM1_PWMX00       GPIO1_IO02  LPI2C1_HREQ           LPSPI3_SDI              ~                      ~
+	D2  = PD4  // [EMC_04]:    SEMC_DATA04      FLEXPWM4_PWMA02  SAI2_TX_DATA     XBAR1_INOUT06   FLEXIO1_FLEXIO04      GPIO4_IO04   ~                     ~                      ~                      ~
+	D3  = PD5  // [EMC_05]:    SEMC_DATA05      FLEXPWM4_PWMB02  SAI2_TX_SYNC     XBAR1_INOUT07   FLEXIO1_FLEXIO05      GPIO4_IO05   ~                     ~                      ~                      ~
+	D4  = PD6  // [EMC_06]:    SEMC_DATA06      FLEXPWM2_PWMA00  SAI2_TX_BCLK     XBAR1_INOUT08   FLEXIO1_FLEXIO06      GPIO4_IO06   ~                     ~                      ~                      ~
+	D5  = PD8  // [EMC_08]:    SEMC_DM00        FLEXPWM2_PWMA01  SAI2_RX_DATA     XBAR1_INOUT17   FLEXIO1_FLEXIO08      GPIO4_IO08   ~                     ~                      ~                      ~
+	D6  = PB10 // [B0_10]:     LCD_DATA06       QTIMER4_TIMER1   FLEXPWM2_PWMA02  SAI1_TX_DATA03  FLEXIO2_FLEXIO10      GPIO2_IO10  SRC_BOOT_CFG06        ENET2_CRS               ~                      ~
+	D7  = PB17 // [B1_01]:     LCD_DATA13       XBAR1_INOUT15    LPUART4_RX       SAI1_TX_DATA00  FLEXIO2_FLEXIO17      GPIO2_IO17  FLEXPWM1_PWMB03       ENET2_RDATA00          FLEXIO3_FLEXIO17        ~
+	D8  = PB16 // [B1_00]:     LCD_DATA12       XBAR1_INOUT14    LPUART4_TX       SAI1_RX_DATA00  FLEXIO2_FLEXIO16      GPIO2_IO16  FLEXPWM1_PWMA03       ENET2_RX_ER            FLEXIO3_FLEXIO16        ~
+	D9  = PB11 // [B0_11]:     LCD_DATA07       QTIMER4_TIMER2   FLEXPWM2_PWMB02  SAI1_TX_DATA02  FLEXIO2_FLEXIO11      GPIO2_IO11  SRC_BOOT_CFG07        ENET2_COL               ~                      ~
+	D10 = PB0  // [B0_00]:     LCD_CLK          QTIMER1_TIMER0   MQS_RIGHT        LPSPI4_PCS0     FLEXIO2_FLEXIO00      GPIO2_IO00  SEMC_CSX01            ENET2_MDC               ~                      ~
+	D11 = PB2  // [B0_02]:     LCD_HSYNC        QTIMER1_TIMER2   FLEXCAN1_TX      LPSPI4_SDO      FLEXIO2_FLEXIO02      GPIO2_IO02  SEMC_CSX03            ENET2_1588_EVENT0_OUT   ~                      ~
+	D12 = PB1  // [B0_01]:     LCD_ENABLE       QTIMER1_TIMER1   MQS_LEFT         LPSPI4_SDI      FLEXIO2_FLEXIO01      GPIO2_IO01  SEMC_CSX02            ENET2_MDIO              ~                      ~
+	D13 = PB3  // [B0_03]:     LCD_VSYNC        QTIMER2_TIMER0   FLEXCAN1_RX      LPSPI4_SCK      FLEXIO2_FLEXIO03      GPIO2_IO03  WDOG2_RESET_B_DEB     ENET2_1588_EVENT0_IN    ~                      ~
+	D14 = PA18 // [AD_B1_02]:  USB_OTG1_ID      QTIMER3_TIMER2   LPUART2_TX       SPDIF_OUT       ENET_1588_EVENT2_OUT  GPIO1_IO18  USDHC1_CD_B           KPP_ROW06              GPT2_CLK               FLEXIO3_FLEXIO02
+	D15 = PA19 // [AD_B1_03]:  USB_OTG1_OC      QTIMER3_TIMER3   LPUART2_RX       SPDIF_IN        ENET_1588_EVENT2_IN   GPIO1_IO19  USDHC2_CD_B           KPP_COL06              GPT2_CAPTURE1          FLEXIO3_FLEXIO03
+	D16 = PA23 // [AD_B1_07]:  FLEXSPIB_DATA00  LPI2C3_SCL       LPUART3_RX       SPDIF_EXT_CLK   CSI_HSYNC             GPIO1_IO23  USDHC2_DATA3          KPP_COL04              GPT2_COMPARE3          FLEXIO3_FLEXIO07
+	D17 = PA22 // [AD_B1_06]:  FLEXSPIB_DATA01  LPI2C3_SDA       LPUART3_TX       SPDIF_LOCK      CSI_VSYNC             GPIO1_IO22  USDHC2_DATA2          KPP_ROW04              GPT2_COMPARE2          FLEXIO3_FLEXIO06
+	D18 = PA17 // [AD_B1_01]:  USB_OTG1_PWR     QTIMER3_TIMER1   LPUART2_RTS_B    LPI2C1_SDA      CCM_PMIC_READY        GPIO1_IO17  USDHC1_VSELECT        KPP_COL07              ENET2_1588_EVENT0_IN   FLEXIO3_FLEXIO01
+	D19 = PA16 // [AD_B1_00]:  USB_OTG2_ID      QTIMER3_TIMER0   LPUART2_CTS_B    LPI2C1_SCL      WDOG1_B               GPIO1_IO16  USDHC1_WP             KPP_ROW07              ENET2_1588_EVENT0_OUT  FLEXIO3_FLEXIO00
+	D20 = PA26 // [AD_B1_10]:  FLEXSPIA_DATA03  WDOG1_B          LPUART8_TX       SAI1_RX_SYNC    CSI_DATA07            GPIO1_IO26  USDHC2_WP             KPP_ROW02              ENET2_1588_EVENT1_OUT  FLEXIO3_FLEXIO10
+	D21 = PA27 // [AD_B1_11]:  FLEXSPIA_DATA02  EWM_OUT_B        LPUART8_RX       SAI1_RX_BCLK    CSI_DATA06            GPIO1_IO27  USDHC2_RESET_B        KPP_COL02              ENET2_1588_EVENT1_IN   FLEXIO3_FLEXIO11
+	D22 = PA24 // [AD_B1_08]:  FLEXSPIA_SS1_B   FLEXPWM4_PWMA00  FLEXCAN1_TX      CCM_PMIC_READY  CSI_DATA09            GPIO1_IO24  USDHC2_CMD            KPP_ROW03              FLEXIO3_FLEXIO08        ~
+	D23 = PA25 // [AD_B1_09]:  FLEXSPIA_DQS     FLEXPWM4_PWMA01  FLEXCAN1_RX      SAI1_MCLK       CSI_DATA08            GPIO1_IO25  USDHC2_CLK            KPP_COL03              FLEXIO3_FLEXIO09        ~
+	D24 = PA12 // [AD_B0_12]:  LPI2C4_SCL       CCM_PMIC_READY   LPUART1_TX       WDOG2_WDOG_B    FLEXPWM1_PWMX02       GPIO1_IO12  ENET_1588_EVENT1_OUT  NMI_GLUE_NMI            ~                      ~
+	D25 = PA13 // [AD_B0_13]:  LPI2C4_SDA       GPT1_CLK         LPUART1_RX       EWM_OUT_B       FLEXPWM1_PWMX03       GPIO1_IO13  ENET_1588_EVENT1_IN   REF_CLK_24M             ~                      ~
+	D26 = PA30 // [AD_B1_14]:  FLEXSPIA_SCLK    ACMP_OUT02       LPSPI3_SDO       SAI1_TX_BCLK    CSI_DATA03            GPIO1_IO30  USDHC2_DATA6          KPP_ROW00              ENET2_1588_EVENT3_OUT  FLEXIO3_FLEXIO14
+	D27 = PA31 // [AD_B1_15]:  FLEXSPIA_SS0_B   ACMP_OUT03       LPSPI3_SCK       SAI1_TX_SYNC    CSI_DATA02            GPIO1_IO31  USDHC2_DATA7          KPP_COL00              ENET2_1588_EVENT3_IN   FLEXIO3_FLEXIO15
+	D28 = PC18 // [EMC_32]:    SEMC_DATA10      FLEXPWM3_PWMB01  LPUART7_RX       CCM_PMIC_RDY    CSI_DATA21            GPIO3_IO18  ENET2_TX_EN            ~                      ~                      ~
+	D29 = PD31 // [EMC_31]:    SEMC_DATA09      FLEXPWM3_PWMA01  LPUART7_TX       LPSPI1_PCS1     CSI_DATA22            GPIO4_IO31  ENET2_TDATA01          ~                      ~                      ~
+	D30 = PC23 // [EMC_37]:    SEMC_DATA15      XBAR1_IN23       GPT1_COMPARE3    SAI3_MCLK       CSI_DATA16            GPIO3_IO23  USDHC2_WP             ENET2_RX_EN            FLEXCAN3_RX             ~
+	D31 = PC22 // [EMC_36]:    SEMC_DATA14      XBAR1_IN22       GPT1_COMPARE2    SAI3_TX_DATA    CSI_DATA17            GPIO3_IO22  USDHC1_WP             ENET2_RDATA01          FLEXCAN3_TX             ~
+	D32 = PB12 // [B0_12]:     LCD_DATA08       XBAR1_INOUT10    ARM_TRACE_CLK    SAI1_TX_DATA01  FLEXIO2_FLEXIO12      GPIO2_IO12  SRC_BOOT_CFG08        ENET2_TDATA00           ~                      ~
+	D33 = PD7  // [EMC_07]:    SEMC_DATA07      FLEXPWM2_PWMB00  SAI2_MCLK        XBAR1_INOUT09   FLEXIO1_FLEXIO07      GPIO4_IO07   ~                     ~                      ~                      ~
+	D34 = PC15 // [SD_B0_03]:  USDHC1_DATA1     FLEXPWM1_PWMB01  LPUART8_RTS_B    XBAR1_INOUT07   LPSPI1_SDI            GPIO3_IO15  ENET2_RDATA00         SEMC_CLK6               ~                      ~
+	D35 = PC14 // [SD_B0_02]:  USDHC1_DATA0     FLEXPWM1_PWMA01  LPUART8_CTS_B    XBAR1_INOUT06   LPSPI1_SDO            GPIO3_IO14  ENET2_RX_ER           SEMC_CLK5               ~                      ~
+	D36 = PC13 // [SD_B0_01]:  USDHC1_CLK       FLEXPWM1_PWMB00  LPI2C3_SDA       XBAR1_INOUT05   LPSPI1_PCS0           GPIO3_IO13  FLEXSPIB_SS1_B        ENET2_TX_CLK           ENET2_REF_CLK2          ~
+	D37 = PC12 // [SD_B0_00]:  USDHC1_CMD       FLEXPWM1_PWMA00  LPI2C3_SCL       XBAR1_INOUT04   LPSPI1_SCK            GPIO3_IO12  FLEXSPIA_SS1_B        ENET2_TX_EN            SEMC_DQS4               ~
+	D38 = PC17 // [SD_B0_05]:  USDHC1_DATA3     FLEXPWM1_PWMB02  LPUART8_RX       XBAR1_INOUT09   FLEXSPIB_DQS          GPIO3_IO17  CCM_CLKO2             ENET2_RX_EN             ~                      ~
+	D39 = PC16 // [SD_B0_04]:  USDHC1_DATA2     FLEXPWM1_PWMA02  LPUART8_TX       XBAR1_INOUT08   FLEXSPIB_SS0_B        GPIO3_IO16  CCM_CLKO1             ENET2_RDATA01           ~                      ~
+)
+
+// Analog pins
+const (
+	//  = Pin  // Dig | [Pad]      {ADC1/ADC2}
+	A0  = PA18 // D14 | [AD_B1_02] {  7 / 7  }
+	A1  = PA19 // D15 | [AD_B1_03] {  8 / 8  }
+	A2  = PA23 // D16 | [AD_B1_07] { 12 / 12 }
+	A3  = PA22 // D17 | [AD_B1_06] { 11 / 11 }
+	A4  = PA17 // D18 | [AD_B1_01] {  6 / 6  }
+	A5  = PA16 // D19 | [AD_B1_00] {  5 / 5  }
+	A6  = PA26 // D20 | [AD_B1_10] { 15 / 15 }
+	A7  = PA27 // D21 | [AD_B1_11] {  0 / 0  }
+	A8  = PA24 // D22 | [AD_B1_08] { 13 / 13 }
+	A9  = PA25 // D23 | [AD_B1_09] { 14 / 14 }
+	A10 = PA12 // D24 | [AD_B0_12] {  1 / -  }
+	A11 = PA13 // D25 | [AD_B0_13] {  2 / -  }
+	A12 = PA30 // D26 | [AD_B1_14] {  - / 3  }
+	A13 = PA31 // D27 | [AD_B1_15] {  - / 4  }
+)
+
+// Default peripheral pins
+const (
+	LED = D13
+
+	UART_RX_PIN = UART1_RX_PIN // D0
+	UART_TX_PIN = UART1_TX_PIN // D1
+
+	SPI_SDI_PIN = SPI1_SDI_PIN // D12
+	SPI_SDO_PIN = SPI1_SDO_PIN // D11
+	SPI_SCK_PIN = SPI1_SCK_PIN // D13
+	SPI_CS_PIN  = SPI1_CS_PIN  // D10
+
+	I2C_SDA_PIN = I2C1_SDA_PIN // D18/A4
+	I2C_SCL_PIN = I2C1_SCL_PIN // D19/A5
+)
+
+func init() {
+	// register any interrupt handlers for this board's peripherals
+	UART1.Interrupt = interrupt.New(nxp.IRQ_LPUART6, UART1.handleInterrupt)
+	UART2.Interrupt = interrupt.New(nxp.IRQ_LPUART4, UART2.handleInterrupt)
+	UART3.Interrupt = interrupt.New(nxp.IRQ_LPUART2, UART3.handleInterrupt)
+	UART4.Interrupt = interrupt.New(nxp.IRQ_LPUART3, UART4.handleInterrupt)
+	UART5.Interrupt = interrupt.New(nxp.IRQ_LPUART8, UART5.handleInterrupt)
+	UART6.Interrupt = interrupt.New(nxp.IRQ_LPUART1, UART6.handleInterrupt)
+	UART7.Interrupt = interrupt.New(nxp.IRQ_LPUART7, UART7.handleInterrupt)
+}
+
+// #=====================================================#
+// |                        UART                         |
+// #===========#===========#=============#===============#
+// | Interface | Hardware  | Clock(Freq) |  RX/TX  : Alt |
+// #===========#===========#=============#=========-=====#
+// |   UART1   |  LPUART6  | OSC(24 MHz) |  D0/D1  : 2/2 |
+// |   UART2   |  LPUART4  | OSC(24 MHz) |  D7/D8  : 2/2 |
+// |   UART3   |  LPUART2  | OSC(24 MHz) | D15/D14 : 2/2 |
+// |   UART4   |  LPUART3  | OSC(24 MHz) | D16/D17 : 2/2 |
+// |   UART5   |  LPUART8  | OSC(24 MHz) | D21/D20 : 2/2 |
+// |   UART6   |  LPUART1  | OSC(24 MHz) | D25/D24 : 2/2 |
+// |   UART7   |  LPUART7  | OSC(24 MHz) | D28/D29 : 2/2 |
+// #===========#===========#=============#=========-=====#
+const (
+	UART1_RX_PIN = D0
+	UART1_TX_PIN = D1
+
+	UART2_RX_PIN = D7
+	UART2_TX_PIN = D8
+
+	UART3_RX_PIN = D15
+	UART3_TX_PIN = D14
+
+	UART4_RX_PIN = D16
+	UART4_TX_PIN = D17
+
+	UART5_RX_PIN = D21
+	UART5_TX_PIN = D20
+
+	UART6_RX_PIN = D25
+	UART6_TX_PIN = D24
+
+	UART7_RX_PIN = D28
+	UART7_TX_PIN = D29
+)
+
+var (
+	UART1 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    nxp.LPUART6,
+		muxRX: muxSelect{ // D0 (PA3 [AD_B0_03])
+			mux: nxp.IOMUXC_LPUART6_RX_SELECT_INPUT_DAISY_GPIO_AD_B0_03_ALT2,
+			sel: &nxp.IOMUXC.LPUART6_RX_SELECT_INPUT,
+		},
+		muxTX: muxSelect{ // D1 (PA2 [AD_B0_02])
+			mux: nxp.IOMUXC_LPUART6_TX_SELECT_INPUT_DAISY_GPIO_AD_B0_02_ALT2,
+			sel: &nxp.IOMUXC.LPUART6_TX_SELECT_INPUT,
+		},
+	}
+	UART2 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    nxp.LPUART4,
+		muxRX: muxSelect{ // D7 (PB17 [B1_01])
+			mux: nxp.IOMUXC_LPUART4_RX_SELECT_INPUT_DAISY_GPIO_B1_01_ALT2,
+			sel: &nxp.IOMUXC.LPUART4_RX_SELECT_INPUT,
+		},
+		muxTX: muxSelect{ // D8 (PB16 [B1_00])
+			mux: nxp.IOMUXC_LPUART4_TX_SELECT_INPUT_DAISY_GPIO_B1_00_ALT2,
+			sel: &nxp.IOMUXC.LPUART4_TX_SELECT_INPUT,
+		},
+	}
+	UART3 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    nxp.LPUART2,
+		muxRX: muxSelect{ // D15 (PA19 [AD_B1_03])
+			mux: nxp.IOMUXC_LPUART2_RX_SELECT_INPUT_DAISY_GPIO_AD_B1_03_ALT2,
+			sel: &nxp.IOMUXC.LPUART2_RX_SELECT_INPUT,
+		},
+		muxTX: muxSelect{ // D14 (PA18 [AD_B1_02])
+			mux: nxp.IOMUXC_LPUART2_TX_SELECT_INPUT_DAISY_GPIO_AD_B1_02_ALT2,
+			sel: &nxp.IOMUXC.LPUART2_TX_SELECT_INPUT,
+		},
+	}
+	UART4 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    nxp.LPUART3,
+		muxRX: muxSelect{ // D16 (PA23 [AD_B1_07])
+			mux: nxp.IOMUXC_LPUART3_RX_SELECT_INPUT_DAISY_GPIO_AD_B1_07_ALT2,
+			sel: &nxp.IOMUXC.LPUART3_RX_SELECT_INPUT,
+		},
+		muxTX: muxSelect{ // D17 (PA22 [AD_B1_06])
+			mux: nxp.IOMUXC_LPUART3_TX_SELECT_INPUT_DAISY_GPIO_AD_B1_06_ALT2,
+			sel: &nxp.IOMUXC.LPUART3_TX_SELECT_INPUT,
+		},
+	}
+	UART5 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    nxp.LPUART8,
+		muxRX: muxSelect{ // D21 (PA27 [AD_B1_11])
+			mux: nxp.IOMUXC_LPUART8_RX_SELECT_INPUT_DAISY_GPIO_AD_B1_11_ALT2,
+			sel: &nxp.IOMUXC.LPUART8_RX_SELECT_INPUT,
+		},
+		muxTX: muxSelect{ // D20 (PA26 [AD_B1_10])
+			mux: nxp.IOMUXC_LPUART8_TX_SELECT_INPUT_DAISY_GPIO_AD_B1_10_ALT2,
+			sel: &nxp.IOMUXC.LPUART8_TX_SELECT_INPUT,
+		},
+	}
+	UART6 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    nxp.LPUART1,
+		// LPUART1 not connected via IOMUXC
+		//   RX: D24 (PA12 [AD_B0_12])
+		//   TX: D25 (PA13 [AD_B0_13])
+	}
+	UART7 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    nxp.LPUART7,
+		muxRX: muxSelect{ // D28 (PC18 [EMC_32])
+			mux: nxp.IOMUXC_LPUART7_RX_SELECT_INPUT_DAISY_GPIO_EMC_32_ALT2,
+			sel: &nxp.IOMUXC.LPUART7_RX_SELECT_INPUT,
+		},
+		muxTX: muxSelect{ // D29 (PD31 [EMC_31])
+			mux: nxp.IOMUXC_LPUART7_TX_SELECT_INPUT_DAISY_GPIO_EMC_31_ALT2,
+			sel: &nxp.IOMUXC.LPUART7_TX_SELECT_INPUT,
+		},
+	}
+)
+
+// #===========#==========#===============#===========================#
+// | Interface | Hardware |  Clock(Freq)  | SDI/SDO/SCK/CS  :   Alt   |
+// #===========#==========#===============#=================-=========#
+// |   SPI1    |  LPSPI4  | PLL2(132 MHz) | D12/D11/D13/D10 : 3/3/3/3 |
+// |   SPI2    |  LPSPI3  | PLL2(132 MHz) |  D1/D26/D27/D0  : 7/2/2/7 |
+// |   SPI3    |  LPSPI1  | PLL2(132 MHz) | D34/D35/D37/D36 : 4/4/4/4 |
+// #===========#==========#===============#=================-=========#
+const (
+	SPI1_SDI_PIN = D12
+	SPI1_SDO_PIN = D11
+	SPI1_SCK_PIN = D13
+	SPI1_CS_PIN  = D10
+
+	SPI2_SDI_PIN = D1
+	SPI2_SDO_PIN = D26
+	SPI2_SCK_PIN = D27
+	SPI2_CS_PIN  = D0
+
+	SPI3_SDI_PIN = D34
+	SPI3_SDO_PIN = D35
+	SPI3_SCK_PIN = D37
+	SPI3_CS_PIN  = D36
+)
+
+// #====================================================#
+// |                         I2C                        |
+// #===========#==========#=============#===============#
+// | Interface | Hardware | Clock(Freq) | SDA/SCL : Alt |
+// #===========#==========#=============#=========-=====#
+// |   I2C1    |  LPI2C1  | OSC(24 MHz) | D18/D19 : 3/3 |
+// |   I2C2    |  LPI2C3  | OSC(24 MHz) | D17/D16 : 1/1 |
+// |   I2C3    |  LPI2C4  | OSC(24 MHz) | D25/D24 : 0/0 |
+// #===========#==========#=============#=========-=====#
+const (
+	I2C1_SDA_PIN = D18
+	I2C1_SCL_PIN = D19
+
+	I2C2_SDA_PIN = D17
+	I2C2_SCL_PIN = D16
+
+	I2C3_SDA_PIN = D25
+	I2C3_SCL_PIN = D24
+)

src/machine/i2c.go

@@ -1,4 +1,4 @@
-// +build avr nrf sam stm32,!stm32f4disco fe310 k210
+// +build avr nrf sam stm32,!stm32f407 fe310 k210
 
 package machine
 

src/machine/machine_atsamd21.go

@@ -165,7 +165,8 @@ func findPinPadMapping(sercom uint8, pin Pin) (pinMode PinMode, pad uint32, ok b
 }
 
 // SetInterrupt sets an interrupt to be executed when a particular pin changes
-// state.
+// state. The pin should already be configured as an input, including a pull up
+// or down if no external pull is provided.
 //
 // This call will replace a previously set callback on this pin. You can pass a
 // nil func to unset the pin change interrupt. If you do so, the change
@@ -1188,7 +1189,10 @@ func (spi SPI) Configure(config SPIConfig) error {
 	}
 
 	// Set synch speed for SPI
-	baudRate := (CPUFrequency() / (2 * config.Frequency)) - 1
+	baudRate := CPUFrequency() / (2 * config.Frequency)
+	if baudRate > 0 {
+		baudRate--
+	}
 	spi.Bus.BAUD.Set(uint8(baudRate))
 
 	// Enable SPI port.

src/machine/machine_atsamd51.go

@@ -353,7 +353,8 @@ func findPinPadMapping(sercom uint8, pin Pin) (pinMode PinMode, pad uint32, ok b
 }
 
 // SetInterrupt sets an interrupt to be executed when a particular pin changes
-// state.
+// state. The pin should already be configured as an input, including a pull up
+// or down if no external pull is provided.
 //
 // This call will replace a previously set callback on this pin. You can pass a
 // nil func to unset the pin change interrupt. If you do so, the change
@@ -1331,12 +1332,13 @@ func (spi SPI) Configure(config SPIConfig) error {
 
 	// Determine the input pinout (for SDI).
 	var dataInPinout uint32
-	SDIPinMode, SDIPad, ok := findPinPadMapping(spi.SERCOM, config.SDI)
+	var SDIPinMode PinMode
 	if config.SDI != NoPin {
+		var ok bool
+		SDIPinMode, dataInPinout, ok = findPinPadMapping(spi.SERCOM, config.SDI)
 		if !ok {
 			return ErrInvalidInputPin
 		}
-		dataInPinout = SDIPad // mapped directly
 	}
 
 	// Determine the output pinout (for SDO/SCK).
@@ -1417,6 +1419,9 @@ func (spi SPI) Configure(config SPIConfig) error {
 
 	// Set synch speed for SPI
 	baudRate := SERCOM_FREQ_REF / (2 * config.Frequency)
+	if baudRate > 0 {
+		baudRate--
+	}
 	spi.Bus.BAUD.Set(uint8(baudRate))
 
 	// Enable SPI port.
@@ -1580,14 +1585,14 @@ func (pwm PWM) setPinCfg(val uint8) {
 // setChannel sets the value for the correct channel for PWM on this pin.
 func (pwm PWM) setChannel(timer *sam.TCC_Type, val uint32) {
 	switch pwm.Pin {
-	case PA16:
-		timer.CC[0].Set(val)
-	case PA17:
-		timer.CC[1].Set(val)
 	case PA14:
 		timer.CC[0].Set(val)
 	case PA15:
 		timer.CC[1].Set(val)
+	case PA16:
+		timer.CC[0].Set(val)
+	case PA17:
+		timer.CC[1].Set(val)
 	case PA18:
 		timer.CC[2].Set(val)
 	case PA19:
@@ -1596,10 +1601,22 @@ func (pwm PWM) setChannel(timer *sam.TCC_Type, val uint32) {
 		timer.CC[0].Set(val)
 	case PA21:
 		timer.CC[1].Set(val)
-	case PA23:
-		timer.CC[3].Set(val)
 	case PA22:
 		timer.CC[2].Set(val)
+	case PA23:
+		timer.CC[3].Set(val)
+	case PB12:
+		timer.CC[0].Set(val)
+	case PB13:
+		timer.CC[1].Set(val)
+	case PB14:
+		timer.CC[0].Set(val)
+	case PB15:
+		timer.CC[1].Set(val)
+	case PB16:
+		timer.CC[4].Set(val)
+	case PB17:
+		timer.CC[5].Set(val)
 	case PB31:
 		timer.CC[1].Set(val)
 	default:
@@ -1610,14 +1627,14 @@ func (pwm PWM) setChannel(timer *sam.TCC_Type, val uint32) {
 // setChannelBuffer sets the value for the correct channel buffer for PWM on this pin
 func (pwm PWM) setChannelBuffer(timer *sam.TCC_Type, val uint32) {
 	switch pwm.Pin {
-	case PA16:
-		timer.CCBUF[0].Set(val)
-	case PA17:
-		timer.CCBUF[1].Set(val)
 	case PA14:
 		timer.CCBUF[0].Set(val)
 	case PA15:
 		timer.CCBUF[1].Set(val)
+	case PA16:
+		timer.CCBUF[0].Set(val)
+	case PA17:
+		timer.CCBUF[1].Set(val)
 	case PA18:
 		timer.CCBUF[2].Set(val)
 	case PA19:
@@ -1626,10 +1643,22 @@ func (pwm PWM) setChannelBuffer(timer *sam.TCC_Type, val uint32) {
 		timer.CCBUF[0].Set(val)
 	case PA21:
 		timer.CCBUF[1].Set(val)
-	case PA23:
-		timer.CCBUF[3].Set(val)
 	case PA22:
 		timer.CCBUF[2].Set(val)
+	case PA23:
+		timer.CCBUF[3].Set(val)
+	case PB12:
+		timer.CCBUF[0].Set(val)
+	case PB13:
+		timer.CCBUF[1].Set(val)
+	case PB14:
+		timer.CCBUF[0].Set(val)
+	case PB15:
+		timer.CCBUF[1].Set(val)
+	case PB16:
+		timer.CCBUF[4].Set(val)
+	case PB17:
+		timer.CCBUF[5].Set(val)
 	case PB31:
 		timer.CCBUF[1].Set(val)
 	default:
@@ -1640,14 +1669,14 @@ func (pwm PWM) setChannelBuffer(timer *sam.TCC_Type, val uint32) {
 // getMux returns the pin mode mux to be used for PWM on this pin.
 func (pwm PWM) getMux() PinMode {
 	switch pwm.Pin {
-	case PA16:
-		return PinPWMF
-	case PA17:
-		return PinPWMF
 	case PA14:
 		return PinPWMF
 	case PA15:
 		return PinPWMF
+	case PA16:
+		return PinPWMF
+	case PA17:
+		return PinPWMF
 	case PA18:
 		return PinPWMF
 	case PA19:
@@ -1656,9 +1685,21 @@ func (pwm PWM) getMux() PinMode {
 		return PinPWMG
 	case PA21:
 		return PinPWMG
+	case PA22:
+		return PinPWMG
 	case PA23:
 		return PinPWMG
-	case PA22:
+	case PB12:
+		return PinPWMF
+	case PB13:
+		return PinPWMF
+	case PB14:
+		return PinPWMF
+	case PB15:
+		return PinPWMF
+	case PB16:
+		return PinPWMG
+	case PB17:
 		return PinPWMG
 	case PB31:
 		return PinPWMF

src/machine/machine_atsamd51g19.go

@@ -18,23 +18,23 @@ func InitPWM() {
 	sam.MCLK.APBCMASK.SetBits(sam.MCLK_APBCMASK_TCC2_)
 
 	//use clock generator 0
-	sam.GCLK.PCHCTRL[25].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC0].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
-	sam.GCLK.PCHCTRL[29].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC2].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
 }
 
 // getTimer returns the timer to be used for PWM on this pin
 func (pwm PWM) getTimer() *sam.TCC_Type {
 	switch pwm.Pin {
-	case PA16:
-		return sam.TCC1
-	case PA17:
-		return sam.TCC1
 	case PA14:
 		return sam.TCC2
 	case PA15:
 		return sam.TCC2
+	case PA16:
+		return sam.TCC1
+	case PA17:
+		return sam.TCC1
 	case PA18:
 		return sam.TCC1
 	case PA19:
@@ -43,10 +43,10 @@ func (pwm PWM) getTimer() *sam.TCC_Type {
 		return sam.TCC0
 	case PA21:
 		return sam.TCC0
-	case PA23:
-		return sam.TCC0
 	case PA22:
 		return sam.TCC0
+	case PA23:
+		return sam.TCC0
 	default:
 		return nil // not supported on this pin
 	}

src/machine/machine_atsamd51j19.go

@@ -3,7 +3,7 @@
 // Peripheral abstraction layer for the atsamd51.
 //
 // Datasheet:
-// http://ww1.microchip.com/downloads/en/DeviceDoc/60001507C.pdf
+// http://ww1.microchip.com/downloads/en/DeviceDoc/SAM_D5xE5x_Family_Data_Sheet_DS60001507F.pdf
 //
 package machine
 
@@ -15,29 +15,29 @@ const HSRAM_SIZE = 0x00030000
 func InitPWM() {
 	// turn on timer clocks used for PWM
 	sam.MCLK.APBBMASK.SetBits(sam.MCLK_APBBMASK_TCC0_ | sam.MCLK_APBBMASK_TCC1_)
-	sam.MCLK.APBCMASK.SetBits(sam.MCLK_APBCMASK_TCC2_)
+	sam.MCLK.APBCMASK.SetBits(sam.MCLK_APBCMASK_TCC2_ | sam.MCLK_APBCMASK_TCC3_)
 	sam.MCLK.APBDMASK.SetBits(sam.MCLK_APBDMASK_TCC4_)
 
 	//use clock generator 0
-	sam.GCLK.PCHCTRL[25].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC0].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
-	sam.GCLK.PCHCTRL[29].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC2].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
-	sam.GCLK.PCHCTRL[38].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC4].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
 }
 
 // getTimer returns the timer to be used for PWM on this pin
 func (pwm PWM) getTimer() *sam.TCC_Type {
 	switch pwm.Pin {
-	case PA16:
-		return sam.TCC1
-	case PA17:
-		return sam.TCC1
 	case PA14:
 		return sam.TCC2
 	case PA15:
 		return sam.TCC2
+	case PA16:
+		return sam.TCC1
+	case PA17:
+		return sam.TCC1
 	case PA18:
 		return sam.TCC1
 	case PA19:
@@ -46,9 +46,21 @@ func (pwm PWM) getTimer() *sam.TCC_Type {
 		return sam.TCC0
 	case PA21:
 		return sam.TCC0
+	case PA22:
+		return sam.TCC0
 	case PA23:
 		return sam.TCC0
-	case PA22:
+	case PB12:
+		return sam.TCC3
+	case PB13:
+		return sam.TCC3
+	case PB14:
+		return sam.TCC4
+	case PB15:
+		return sam.TCC4
+	case PB16:
+		return sam.TCC0
+	case PB17:
 		return sam.TCC0
 	case PB31:
 		return sam.TCC4

src/machine/machine_atsamd51j20.go

@@ -15,29 +15,29 @@ const HSRAM_SIZE = 0x00040000
 func InitPWM() {
 	// turn on timer clocks used for PWM
 	sam.MCLK.APBBMASK.SetBits(sam.MCLK_APBBMASK_TCC0_ | sam.MCLK_APBBMASK_TCC1_)
-	sam.MCLK.APBCMASK.SetBits(sam.MCLK_APBCMASK_TCC2_)
+	sam.MCLK.APBCMASK.SetBits(sam.MCLK_APBCMASK_TCC2_ | sam.MCLK_APBCMASK_TCC3_)
 	sam.MCLK.APBDMASK.SetBits(sam.MCLK_APBDMASK_TCC4_)
 
 	//use clock generator 0
-	sam.GCLK.PCHCTRL[25].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC0].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
-	sam.GCLK.PCHCTRL[29].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC2].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
-	sam.GCLK.PCHCTRL[38].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC4].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
 }
 
 // getTimer returns the timer to be used for PWM on this pin
 func (pwm PWM) getTimer() *sam.TCC_Type {
 	switch pwm.Pin {
-	case PA16:
-		return sam.TCC1
-	case PA17:
-		return sam.TCC1
 	case PA14:
 		return sam.TCC2
 	case PA15:
 		return sam.TCC2
+	case PA16:
+		return sam.TCC1
+	case PA17:
+		return sam.TCC1
 	case PA18:
 		return sam.TCC1
 	case PA19:
@@ -46,9 +46,21 @@ func (pwm PWM) getTimer() *sam.TCC_Type {
 		return sam.TCC0
 	case PA21:
 		return sam.TCC0
+	case PA22:
+		return sam.TCC0
 	case PA23:
 		return sam.TCC0
-	case PA22:
+	case PB12:
+		return sam.TCC3
+	case PB13:
+		return sam.TCC3
+	case PB14:
+		return sam.TCC4
+	case PB15:
+		return sam.TCC4
+	case PB16:
+		return sam.TCC0
+	case PB17:
 		return sam.TCC0
 	case PB31:
 		return sam.TCC4

src/machine/machine_atsamd51p19.go

@@ -15,29 +15,29 @@ const HSRAM_SIZE = 0x00030000
 func InitPWM() {
 	// turn on timer clocks used for PWM
 	sam.MCLK.APBBMASK.SetBits(sam.MCLK_APBBMASK_TCC0_ | sam.MCLK_APBBMASK_TCC1_)
-	sam.MCLK.APBCMASK.SetBits(sam.MCLK_APBCMASK_TCC2_)
+	sam.MCLK.APBCMASK.SetBits(sam.MCLK_APBCMASK_TCC2_ | sam.MCLK_APBCMASK_TCC3_)
 	sam.MCLK.APBDMASK.SetBits(sam.MCLK_APBDMASK_TCC4_)
 
 	//use clock generator 0
-	sam.GCLK.PCHCTRL[25].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC0].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
-	sam.GCLK.PCHCTRL[29].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC2].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
-	sam.GCLK.PCHCTRL[38].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
+	sam.GCLK.PCHCTRL[sam.PCHCTRL_GCLK_TCC4].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) |
 		sam.GCLK_PCHCTRL_CHEN)
 }
 
 // getTimer returns the timer to be used for PWM on this pin
 func (pwm PWM) getTimer() *sam.TCC_Type {
 	switch pwm.Pin {
-	case PA16:
-		return sam.TCC1
-	case PA17:
-		return sam.TCC1
 	case PA14:
 		return sam.TCC2
 	case PA15:
 		return sam.TCC2
+	case PA16:
+		return sam.TCC1
+	case PA17:
+		return sam.TCC1
 	case PA18:
 		return sam.TCC1
 	case PA19:
@@ -46,9 +46,21 @@ func (pwm PWM) getTimer() *sam.TCC_Type {
 		return sam.TCC0
 	case PA21:
 		return sam.TCC0
+	case PA22:
+		return sam.TCC0
 	case PA23:
 		return sam.TCC0
-	case PA22:
+	case PB12:
+		return sam.TCC3
+	case PB13:
+		return sam.TCC3
+	case PB14:
+		return sam.TCC4
+	case PB15:
+		return sam.TCC4
+	case PB16:
+		return sam.TCC0
+	case PB17:
 		return sam.TCC0
 	case PB31:
 		return sam.TCC4

src/machine/machine_esp32.go

@@ -0,0 +1,503 @@
+// +build esp32
+
+package machine
+
+import (
+	"device/esp"
+	"errors"
+	"runtime/volatile"
+	"unsafe"
+)
+
+const peripheralClock = 80000000 // 80MHz
+
+// CPUFrequency returns the current CPU frequency of the chip.
+// Currently it is a fixed frequency but it may allow changing in the future.
+func CPUFrequency() uint32 {
+	return 160e6 // 160MHz
+}
+
+var (
+	ErrInvalidSPIBus = errors.New("machine: invalid SPI bus")
+)
+
+type PinMode uint8
+
+const (
+	PinOutput PinMode = iota
+	PinInput
+	PinInputPullup
+	PinInputPulldown
+)
+
+// Configure this pin with the given configuration.
+func (p Pin) Configure(config PinConfig) {
+	// Output function 256 is a special value reserved for use as a regular GPIO
+	// pin. Peripherals (SPI etc) can set a custom output function by calling
+	// lowercase configure() instead with a signal name.
+	p.configure(config, 256)
+}
+
+// configure is the same as Configure, but allows for setting a specific input
+// or output signal.
+// Signals are always routed through the GPIO matrix for simplicity. Output
+// signals are configured in FUNCx_OUT_SEL_CFG which selects a particular signal
+// to output on a given pin. Input signals are configured in FUNCy_IN_SEL_CFG,
+// which sets the pin to use for a particular input signal.
+func (p Pin) configure(config PinConfig, signal uint32) {
+	if p == NoPin {
+		// This simplifies pin configuration in peripherals such as SPI.
+		return
+	}
+
+	var muxConfig uint32 // The mux configuration.
+
+	// Configure this pin as a GPIO pin.
+	const function = 3 // function 3 is GPIO for every pin
+	muxConfig |= (function - 1) << esp.IO_MUX_GPIO0_MCU_SEL_Pos
+
+	// Make this pin an input pin (always).
+	muxConfig |= esp.IO_MUX_GPIO0_FUN_IE
+
+	// Set drive strength: 0 is lowest, 3 is highest.
+	muxConfig |= 2 << esp.IO_MUX_GPIO0_FUN_DRV_Pos
+
+	// Select pull mode.
+	if config.Mode == PinInputPullup {
+		muxConfig |= esp.IO_MUX_GPIO0_FUN_WPU
+	} else if config.Mode == PinInputPulldown {
+		muxConfig |= esp.IO_MUX_GPIO0_FUN_WPD
+	}
+
+	// Configure the pad with the given IO mux configuration.
+	p.mux().Set(muxConfig)
+
+	switch config.Mode {
+	case PinOutput:
+		// Set the 'output enable' bit.
+		if p < 32 {
+			esp.GPIO.ENABLE_W1TS.Set(1 << p)
+		} else {
+			esp.GPIO.ENABLE1_W1TS.Set(1 << (p - 32))
+		}
+		// Set the signal to read the output value from. It can be a peripheral
+		// output signal, or the special value 256 which indicates regular GPIO
+		// usage.
+		p.outFunc().Set(signal)
+	case PinInput, PinInputPullup, PinInputPulldown:
+		// Clear the 'output enable' bit.
+		if p < 32 {
+			esp.GPIO.ENABLE_W1TC.Set(1 << p)
+		} else {
+			esp.GPIO.ENABLE1_W1TC.Set(1 << (p - 32))
+		}
+		if signal != 256 {
+			// Signal is a peripheral function (not a simple GPIO). Connect this
+			// signal to the pin.
+			// Note that outFunc and inFunc work in the opposite direction.
+			// outFunc configures a pin to use a given output signal, while
+			// inFunc specifies a pin to use to read the signal from.
+			inFunc(signal).Set(esp.GPIO_FUNC_IN_SEL_CFG_SEL | uint32(p)<<esp.GPIO_FUNC_IN_SEL_CFG_IN_SEL_Pos)
+		}
+	}
+}
+
+// outFunc returns the FUNCx_OUT_SEL_CFG register used for configuring the
+// output function selection.
+func (p Pin) outFunc() *volatile.Register32 {
+	return (*volatile.Register32)(unsafe.Pointer((uintptr(unsafe.Pointer(&esp.GPIO.FUNC0_OUT_SEL_CFG)) + uintptr(p)*4)))
+}
+
+// inFunc returns the FUNCy_IN_SEL_CFG register used for configuring the input
+// function selection.
+func inFunc(signal uint32) *volatile.Register32 {
+	return (*volatile.Register32)(unsafe.Pointer((uintptr(unsafe.Pointer(&esp.GPIO.FUNC0_IN_SEL_CFG)) + uintptr(signal)*4)))
+}
+
+// Set the pin to high or low.
+// Warning: only use this on an output pin!
+func (p Pin) Set(value bool) {
+	if value {
+		reg, mask := p.portMaskSet()
+		reg.Set(mask)
+	} else {
+		reg, mask := p.portMaskClear()
+		reg.Set(mask)
+	}
+}
+
+// Return the register and mask to enable a given GPIO pin. This can be used to
+// implement bit-banged drivers.
+//
+// Warning: only use this on an output pin!
+func (p Pin) PortMaskSet() (*uint32, uint32) {
+	reg, mask := p.portMaskSet()
+	return &reg.Reg, mask
+}
+
+// Return the register and mask to disable a given GPIO pin. This can be used to
+// implement bit-banged drivers.
+//
+// Warning: only use this on an output pin!
+func (p Pin) PortMaskClear() (*uint32, uint32) {
+	reg, mask := p.portMaskClear()
+	return &reg.Reg, mask
+}
+
+func (p Pin) portMaskSet() (*volatile.Register32, uint32) {
+	if p < 32 {
+		return &esp.GPIO.OUT_W1TS, 1 << p
+	} else {
+		return &esp.GPIO.OUT1_W1TS, 1 << (p - 32)
+	}
+}
+
+func (p Pin) portMaskClear() (*volatile.Register32, uint32) {
+	if p < 32 {
+		return &esp.GPIO.OUT_W1TC, 1 << p
+	} else {
+		return &esp.GPIO.OUT1_W1TC, 1 << (p - 32)
+	}
+}
+
+// Get returns the current value of a GPIO pin when the pin is configured as an
+// input.
+func (p Pin) Get() bool {
+	if p < 32 {
+		return esp.GPIO.IN.Get()&(1<<p) != 0
+	} else {
+		return esp.GPIO.IN1.Get()&(1<<(p-32)) != 0
+	}
+}
+
+// mux returns the I/O mux configuration register corresponding to the given
+// GPIO pin.
+func (p Pin) mux() *volatile.Register32 {
+	// I have no idea whether there is any pattern in the GPIO <-> pad mapping.
+	// I couldn't find it.
+	switch p {
+	case 36:
+		return &esp.IO_MUX.GPIO36
+	case 37:
+		return &esp.IO_MUX.GPIO37
+	case 38:
+		return &esp.IO_MUX.GPIO38
+	case 39:
+		return &esp.IO_MUX.GPIO39
+	case 34:
+		return &esp.IO_MUX.GPIO34
+	case 35:
+		return &esp.IO_MUX.GPIO35
+	case 32:
+		return &esp.IO_MUX.GPIO32
+	case 33:
+		return &esp.IO_MUX.GPIO33
+	case 25:
+		return &esp.IO_MUX.GPIO25
+	case 26:
+		return &esp.IO_MUX.GPIO26
+	case 27:
+		return &esp.IO_MUX.GPIO27
+	case 14:
+		return &esp.IO_MUX.MTMS
+	case 12:
+		return &esp.IO_MUX.MTDI
+	case 13:
+		return &esp.IO_MUX.MTCK
+	case 15:
+		return &esp.IO_MUX.MTDO
+	case 2:
+		return &esp.IO_MUX.GPIO2
+	case 0:
+		return &esp.IO_MUX.GPIO0
+	case 4:
+		return &esp.IO_MUX.GPIO4
+	case 16:
+		return &esp.IO_MUX.GPIO16
+	case 17:
+		return &esp.IO_MUX.GPIO17
+	case 9:
+		return &esp.IO_MUX.SD_DATA2
+	case 10:
+		return &esp.IO_MUX.SD_DATA3
+	case 11:
+		return &esp.IO_MUX.SD_CMD
+	case 6:
+		return &esp.IO_MUX.SD_CLK
+	case 7:
+		return &esp.IO_MUX.SD_DATA0
+	case 8:
+		return &esp.IO_MUX.SD_DATA1
+	case 5:
+		return &esp.IO_MUX.GPIO5
+	case 18:
+		return &esp.IO_MUX.GPIO18
+	case 19:
+		return &esp.IO_MUX.GPIO19
+	case 20:
+		return &esp.IO_MUX.GPIO20
+	case 21:
+		return &esp.IO_MUX.GPIO21
+	case 22:
+		return &esp.IO_MUX.GPIO22
+	case 3:
+		return &esp.IO_MUX.U0RXD
+	case 1:
+		return &esp.IO_MUX.U0TXD
+	case 23:
+		return &esp.IO_MUX.GPIO23
+	case 24:
+		return &esp.IO_MUX.GPIO24
+	default:
+		return nil
+	}
+}
+
+var (
+	UART0 = UART{Bus: esp.UART0, Buffer: NewRingBuffer()}
+	UART1 = UART{Bus: esp.UART1, Buffer: NewRingBuffer()}
+	UART2 = UART{Bus: esp.UART2, Buffer: NewRingBuffer()}
+)
+
+type UART struct {
+	Bus    *esp.UART_Type
+	Buffer *RingBuffer
+}
+
+func (uart UART) Configure(config UARTConfig) {
+	if config.BaudRate == 0 {
+		config.BaudRate = 115200
+	}
+	uart.Bus.CLKDIV.Set(peripheralClock / config.BaudRate)
+}
+
+func (uart UART) WriteByte(b byte) error {
+	for (uart.Bus.STATUS.Get()>>16)&0xff >= 128 {
+		// Read UART_TXFIFO_CNT from the status register, which indicates how
+		// many bytes there are in the transmit buffer. Wait until there are
+		// less than 128 bytes in this buffer (the default buffer size).
+	}
+	uart.Bus.TX_FIFO.Set(b)
+	return nil
+}
+
+// Serial Peripheral Interface on the ESP32.
+type SPI struct {
+	Bus *esp.SPI_Type
+}
+
+var (
+	// SPI0 and SPI1 are reserved for use by the caching system etc.
+	SPI2 = SPI{esp.SPI2}
+	SPI3 = SPI{esp.SPI3}
+)
+
+// SPIConfig configures a SPI peripheral on the ESP32. Make sure to set at least
+// SCK, SDO and SDI (possibly to NoPin if not in use). The default for LSBFirst
+// (false) and Mode (0) are good for most applications. The frequency defaults
+// to 1MHz if not set but can be configured up to 40MHz. Possible values are
+// 40MHz and integer divisions from 40MHz such as 20MHz, 13.3MHz, 10MHz, 8MHz,
+// etc.
+type SPIConfig struct {
+	Frequency uint32
+	SCK       Pin
+	SDO       Pin
+	SDI       Pin
+	LSBFirst  bool
+	Mode      uint8
+}
+
+// Configure and make the SPI peripheral ready to use.
+func (spi SPI) Configure(config SPIConfig) error {
+	if config.Frequency == 0 {
+		config.Frequency = 4e6 // default to 4MHz
+	}
+
+	// Configure the SPI clock. This assumes a peripheral clock of 80MHz.
+	var clockReg uint32
+	if config.Frequency >= 40e6 {
+		// Don't use a prescaler, but directly connect to the APB clock. This
+		// results in a SPI clock frequency of 40MHz.
+		clockReg |= esp.SPI_CLOCK_CLK_EQU_SYSCLK
+	} else {
+		// Use a prescaler for frequencies below 40MHz. They will get rounded
+		// down to the next possible frequency (20MHz, 13.3MHz, 10MHz, 8MHz,
+		// 6.7MHz, 5.7MHz, 5MHz, etc).
+		// This code is much simpler than how ESP-IDF configures the frequency,
+		// but should be just as accurate. The only exception is for frequencies
+		// below 4883Hz, which will need special support.
+		if config.Frequency < 4883 {
+			// The current lower limit is 4883Hz.
+			// The hardware supports lower frequencies by setting the h and n
+			// variables, but that's not yet implemented.
+			config.Frequency = 4883
+		}
+		// The prescaler value is 40e6 / config.Frequency, but rounded up so
+		// that the actual frequency is never higher than the frequency
+		// requested in config.Frequency.
+		var (
+			pre uint32 = (40e6 + config.Frequency - 1) / config.Frequency
+			n   uint32 = 2 // this value seems to equal the number of ticks per SPI clock tick
+			h   uint32 = 1 // must be half of n according to the formula in the reference manual
+			l   uint32 = n // must equal n according to the reference manual
+		)
+		clockReg |= (pre - 1) << esp.SPI_CLOCK_CLKDIV_PRE_Pos
+		clockReg |= (n - 1) << esp.SPI_CLOCK_CLKCNT_N_Pos
+		clockReg |= (h - 1) << esp.SPI_CLOCK_CLKCNT_H_Pos
+		clockReg |= (l - 1) << esp.SPI_CLOCK_CLKCNT_L_Pos
+	}
+	spi.Bus.CLOCK.Set(clockReg)
+
+	// SPI_CTRL_REG controls bit order.
+	var ctrlReg uint32
+	if config.LSBFirst {
+		ctrlReg |= esp.SPI_CTRL_WR_BIT_ORDER
+		ctrlReg |= esp.SPI_CTRL_RD_BIT_ORDER
+	}
+	spi.Bus.CTRL.Set(ctrlReg)
+
+	// SPI_CTRL2_REG, SPI_USER_REG and SPI_PIN_REG control SPI clock polarity
+	// (mode), among others.
+	var ctrl2Reg, userReg, pinReg uint32
+	// For mode configuration, see table 29 in the reference manual (page 128).
+	var delayMode uint32
+	switch config.Mode {
+	case 0:
+		delayMode = 2
+	case 1:
+		delayMode = 1
+		userReg |= esp.SPI_USER_CK_OUT_EDGE
+	case 2:
+		delayMode = 1
+		userReg |= esp.SPI_USER_CK_OUT_EDGE
+		pinReg |= esp.SPI_PIN_CK_IDLE_EDGE
+	case 3:
+		delayMode = 2
+		pinReg |= esp.SPI_PIN_CK_IDLE_EDGE
+	}
+	// Extra configuration necessary for correct data input at high frequencies.
+	// This is only necessary when MISO goes through the GPIO matrix (which it
+	// currently does).
+	if config.Frequency >= 40e6 {
+		// Delay mode must be set to 0 and SPI_USR_DUMMY_CYCLELEN should be set
+		// to 0 (the default).
+		userReg |= esp.SPI_USER_USR_DUMMY
+	} else if config.Frequency >= 20e6 {
+		// Nothing to do here, delay mode should be set to 0 according to the
+		// datasheet.
+	} else {
+		// Follow the delay mode as given in table 29 on page 128 of the
+		// reference manual.
+		// Note that this is only specified for SPI frequency of 10MHz and
+		// below (≤Fapb/8), so 13.3MHz appears to be left unspecified.
+		ctrl2Reg |= delayMode << esp.SPI_CTRL2_MOSI_DELAY_MODE_Pos
+	}
+	// Enable full-duplex communication.
+	userReg |= esp.SPI_USER_DOUTDIN
+	userReg |= esp.SPI_USER_USR_MOSI
+	// Write values to registers.
+	spi.Bus.CTRL2.Set(ctrl2Reg)
+	spi.Bus.USER.Set(userReg)
+	spi.Bus.PIN.Set(pinReg)
+
+	// Configure pins.
+	// TODO: use direct output if possible, if the configured pins match the
+	// possible direct configurations (e.g. for SPI2, when SCK is pin 14 etc).
+	if spi.Bus == esp.SPI2 {
+		config.SCK.configure(PinConfig{Mode: PinOutput}, 8)  // HSPICLK
+		config.SDI.configure(PinConfig{Mode: PinInput}, 9)   // HSPIQ
+		config.SDO.configure(PinConfig{Mode: PinOutput}, 10) // HSPID
+	} else if spi.Bus == esp.SPI3 {
+		config.SCK.configure(PinConfig{Mode: PinOutput}, 63) // VSPICLK
+		config.SDI.configure(PinConfig{Mode: PinInput}, 64)  // VSPIQ
+		config.SDO.configure(PinConfig{Mode: PinOutput}, 65) // VSPID
+	} else {
+		// Don't know how to configure this bus.
+		return ErrInvalidSPIBus
+	}
+
+	return nil
+}
+
+// Transfer writes/reads a single byte using the SPI interface. If you need to
+// transfer larger amounts of data, Tx will be faster.
+func (spi SPI) Transfer(w byte) (byte, error) {
+	spi.Bus.MISO_DLEN.Set(7 << esp.SPI_MISO_DLEN_USR_MISO_DBITLEN_Pos)
+	spi.Bus.MOSI_DLEN.Set(7 << esp.SPI_MOSI_DLEN_USR_MOSI_DBITLEN_Pos)
+
+	spi.Bus.W0.Set(uint32(w))
+
+	// Send/receive byte.
+	spi.Bus.CMD.Set(esp.SPI_CMD_USR)
+	for spi.Bus.CMD.Get() != 0 {
+	}
+
+	// The received byte is stored in W0.
+	return byte(spi.Bus.W0.Get()), nil
+}
+
+// Tx handles read/write operation for SPI interface. Since SPI is a syncronous write/read
+// interface, there must always be the same number of bytes written as bytes read.
+// This is accomplished by sending zero bits if r is bigger than w or discarding
+// the incoming data if w is bigger than r.
+//
+func (spi SPI) Tx(w, r []byte) error {
+	toTransfer := len(w)
+	if len(r) > toTransfer {
+		toTransfer = len(r)
+	}
+
+	for toTransfer != 0 {
+		// Do only 64 bytes at a time.
+		chunkSize := toTransfer
+		if chunkSize > 64 {
+			chunkSize = 64
+		}
+
+		// Fill tx buffer.
+		transferWords := (*[16]volatile.Register32)(unsafe.Pointer(uintptr(unsafe.Pointer(&spi.Bus.W0))))
+		var outBuf [16]uint32
+		txSize := 64
+		if txSize > len(w) {
+			txSize = len(w)
+		}
+		for i := 0; i < txSize; i++ {
+			outBuf[i/4] = outBuf[i/4] | uint32(w[i])<<((i%4)*8)
+		}
+		for i, word := range outBuf {
+			transferWords[i].Set(word)
+		}
+
+		// Do the transfer.
+		spi.Bus.MISO_DLEN.Set((uint32(chunkSize)*8 - 1) << esp.SPI_MISO_DLEN_USR_MISO_DBITLEN_Pos)
+		spi.Bus.MOSI_DLEN.Set((uint32(chunkSize)*8 - 1) << esp.SPI_MOSI_DLEN_USR_MOSI_DBITLEN_Pos)
+		spi.Bus.CMD.Set(esp.SPI_CMD_USR)
+		for spi.Bus.CMD.Get() != 0 {
+		}
+
+		// Read rx buffer.
+		rxSize := 64
+		if rxSize > len(r) {
+			rxSize = len(r)
+		}
+		for i := 0; i < rxSize; i++ {
+			r[i] = byte(transferWords[i/4].Get() >> ((i % 4) * 8))
+		}
+
+		// Cut off some part of the output buffer so the next iteration we will
+		// only send the remaining bytes.
+		if len(w) < chunkSize {
+			w = nil
+		} else {
+			w = w[chunkSize:]
+		}
+		if len(r) < chunkSize {
+			r = nil
+		} else {
+			r = r[chunkSize:]
+		}
+		toTransfer -= chunkSize
+	}
+
+	return nil
+}

src/machine/machine_esp8266.go

@@ -0,0 +1,168 @@
+// +build esp8266
+
+package machine
+
+import (
+	"device/esp"
+	"runtime/volatile"
+)
+
+func CPUFrequency() uint32 {
+	return 80000000 // 80MHz
+}
+
+type PinMode uint8
+
+const (
+	PinOutput PinMode = iota
+	PinInput
+)
+
+// Pins that are fixed by the chip.
+const (
+	UART_TX_PIN Pin = 1
+	UART_RX_PIN Pin = 3
+)
+
+// Pin functions are not trivial. The below array maps a pin number (GPIO
+// number) to the pad as used in the IO mux.
+// Tables with the mapping:
+// https://www.esp8266.com/wiki/doku.php?id=esp8266_gpio_pin_allocations#pin_functions
+// https://www.espressif.com/sites/default/files/documentation/ESP8266_Pin_List_0.xls
+var pinPadMapping = [...]uint8{
+	12: 0,
+	13: 1,
+	14: 2,
+	15: 3,
+	3:  4,
+	1:  5,
+	6:  6,
+	7:  7,
+	8:  8,
+	9:  9,
+	10: 10,
+	11: 11,
+	0:  12,
+	2:  13,
+	4:  14,
+	5:  15,
+}
+
+// getPad returns the pad number and the register to configure this pad.
+func (p Pin) getPad() (uint8, *volatile.Register32) {
+	pad := pinPadMapping[p]
+	var reg *volatile.Register32
+	switch pad {
+	case 0:
+		reg = &esp.IO_MUX.IO_MUX_MTDI
+	case 1:
+		reg = &esp.IO_MUX.IO_MUX_MTCK
+	case 2:
+		reg = &esp.IO_MUX.IO_MUX_MTMS
+	case 3:
+		reg = &esp.IO_MUX.IO_MUX_MTDO
+	case 4:
+		reg = &esp.IO_MUX.IO_MUX_U0RXD
+	case 5:
+		reg = &esp.IO_MUX.IO_MUX_U0TXD
+	case 6:
+		reg = &esp.IO_MUX.IO_MUX_SD_CLK
+	case 7:
+		reg = &esp.IO_MUX.IO_MUX_SD_DATA0
+	case 8:
+		reg = &esp.IO_MUX.IO_MUX_SD_DATA1
+	case 9:
+		reg = &esp.IO_MUX.IO_MUX_SD_DATA2
+	case 10:
+		reg = &esp.IO_MUX.IO_MUX_SD_DATA3
+	case 11:
+		reg = &esp.IO_MUX.IO_MUX_SD_CMD
+	case 12:
+		reg = &esp.IO_MUX.IO_MUX_GPIO0
+	case 13:
+		reg = &esp.IO_MUX.IO_MUX_GPIO2
+	case 14:
+		reg = &esp.IO_MUX.IO_MUX_GPIO4
+	case 15:
+		reg = &esp.IO_MUX.IO_MUX_GPIO5
+	}
+	return pad, reg
+}
+
+// Configure sets the given pin as output or input pin.
+func (p Pin) Configure(config PinConfig) {
+	switch config.Mode {
+	case PinInput, PinOutput:
+		pad, reg := p.getPad()
+		if pad >= 12 { // pin 0, 2, 4, 5
+			reg.Set(0 << 4) // function 0 at bit position 4
+		} else {
+			reg.Set(3 << 4) // function 3 at bit position 4
+		}
+		if config.Mode == PinOutput {
+			esp.GPIO.GPIO_ENABLE_W1TS.Set(1 << p)
+		} else {
+			esp.GPIO.GPIO_ENABLE_W1TC.Set(1 << p)
+		}
+	}
+}
+
+// Get returns the current value of a GPIO pin when the pin is configured as an
+// input.
+func (p Pin) Get() bool {
+	// See this document for details
+	// https://www.espressif.com/sites/default/files/documentation/esp8266-technical_reference_en.pdf
+
+	return esp.GPIO.GPIO_IN.Get()&(1<<p) != 0
+}
+
+// Set sets the output value of this pin to high (true) or low (false).
+func (p Pin) Set(value bool) {
+	if value {
+		esp.GPIO.GPIO_OUT_W1TS.Set(1 << p)
+	} else {
+		esp.GPIO.GPIO_OUT_W1TC.Set(1 << p)
+	}
+}
+
+// Return the register and mask to enable a given GPIO pin. This can be used to
+// implement bit-banged drivers.
+//
+// Warning: only use this on an output pin!
+func (p Pin) PortMaskSet() (*uint32, uint32) {
+	return &esp.GPIO.GPIO_OUT_W1TS.Reg, 1 << p
+}
+
+// Return the register and mask to disable a given GPIO pin. This can be used to
+// implement bit-banged drivers.
+//
+// Warning: only use this on an output pin!
+func (p Pin) PortMaskClear() (*uint32, uint32) {
+	return &esp.GPIO.GPIO_OUT_W1TC.Reg, 1 << p
+}
+
+// UART0 is a hardware UART that supports both TX and RX.
+var UART0 = UART{Buffer: NewRingBuffer()}
+
+type UART struct {
+	Buffer *RingBuffer
+}
+
+// Configure the UART baud rate. TX and RX pins are fixed by the hardware so
+// cannot be modified and will be ignored.
+func (uart UART) Configure(config UARTConfig) {
+	if config.BaudRate == 0 {
+		config.BaudRate = 115200
+	}
+	esp.UART0.UART_CLKDIV.Set(CPUFrequency() / config.BaudRate)
+}
+
+// WriteByte writes a single byte to the output buffer. Note that the hardware
+// includes a buffer of 128 bytes which will be used first.
+func (uart UART) WriteByte(c byte) error {
+	for (esp.UART0.UART_STATUS.Get()>>16)&0xff >= 128 {
+		// Wait until the TX buffer has room.
+	}
+	esp.UART0.UART_FIFO.Set(uint32(c))
+	return nil
+}

src/machine/machine_fe310.go

@@ -123,7 +123,7 @@ func (spi SPI) Configure(config SPIConfig) error {
 
 	// set default frequency
 	if config.Frequency == 0 {
-		config.Frequency = 4000000
+		config.Frequency = 4000000 // 4MHz
 	}
 
 	// div = (SPI_CFG(dev)->f_sys / (2 * frequency)) - 1;

src/machine/machine_k210.go

@@ -172,7 +172,8 @@ func (p Pin) Get() bool {
 var pinCallbacks [32]func(Pin)
 
 // SetInterrupt sets an interrupt to be executed when a particular pin changes
-// state.
+// state. The pin should already be configured as an input, including a pull up
+// or down if no external pull is provided.
 //
 // You can pass a nil func to unset the pin change interrupt. If you do so,
 // the change parameter is ignored and can be set to any value (such as 0).
@@ -442,7 +443,7 @@ func (spi SPI) Configure(config SPIConfig) error {
 
 	// Set default frequency.
 	if config.Frequency == 0 {
-		config.Frequency = 500000
+		config.Frequency = 4000000 // 4MHz
 	}
 
 	baudr := CPUFrequency() / config.Frequency

src/machine/machine_mimxrt1062.go

@@ -0,0 +1,881 @@
+// +build mimxrt1062
+
+package machine
+
+import (
+	"device/nxp"
+	"math/bits"
+	"runtime/interrupt"
+	"runtime/volatile"
+)
+
+// Peripheral abstraction layer for the MIMXRT1062
+
+func CPUFrequency() uint32 {
+	return 600000000
+}
+
+type PinMode uint8
+
+const (
+	// GPIO
+	PinInput PinMode = iota
+	PinInputPullUp
+	PinInputPullDown
+	PinOutput
+	PinOutputOpenDrain
+	PinDisable
+
+	// ADC
+	PinInputAnalog
+
+	// UART
+	PinModeUARTTX
+	PinModeUARTRX
+
+	// SPI
+	PinModeSPISDI
+	PinModeSPISDO
+	PinModeSPICLK
+	PinModeSPICS
+
+	// I2C
+	PinModeI2CSDA
+	PinModeI2CSCL
+)
+
+type PinChange uint8
+
+const (
+	PinLow PinChange = iota
+	PinHigh
+	PinRising
+	PinFalling
+	PinToggle
+)
+
+// pinJumpTable represents a function lookup table for all 128 GPIO pins.
+//
+// There are 4 GPIO ports (A-D) and 32 pins (0-31) on each port. The uint8 value
+// of a Pin is used as table index. The number of pins with a defined (non-nil)
+// function is recorded in the uint8 field numDefined.
+type pinJumpTable struct {
+	lut        [4 * 32]func(Pin)
+	numDefined uint8
+}
+
+// pinISR stores the interrupt callbacks for GPIO pins, and pinInterrupt holds
+// an interrupt service routine that dispatches the interrupt callbacks.
+var (
+	pinISR       pinJumpTable
+	pinInterrupt *interrupt.Interrupt
+)
+
+// From the i.MXRT1062 Processor Reference Manual (Chapter 12 - GPIO):
+//
+// |  High-speed GPIOs exist in this device:
+// |    - GPIO1-5 are standard-speed GPIOs that run off the IPG_CLK_ROOT, while
+// |      GPIO6-9 are high-speed GPIOs that run at the AHB_CLK_ROOT frequency.
+// |      See the table "System Clocks, Gating, and Override" in CCM chapter.
+// |    - Regular GPIO and high speed GPIO are paired (GPIO1 and GPIO6 share the
+// |      same pins, GPIO2 and GPIO7 share, etc). The IOMUXC_GPR_GPR26-29
+// |      registers are used to determine if the regular or high-speed GPIO
+// |      module is used for the GPIO pins on a given port.
+//
+// Therefore, we do not even use GPIO1-5 and instead use their high-speed
+// partner for all pins. This is configured at startup in the runtime package
+// (func initPins() in `runtime_mimxrt1062.go`).
+// We cannot declare 32 pins for all available ports (GPIO1-9) anyway, since Pin
+// is only uint8, and 9*32=288 > 256, so something has to be sacrificed.
+
+const (
+	portA Pin = iota * 32 // GPIO1(6)
+	portB                 // GPIO2(7)
+	portC                 // GPIO3(8)
+	portD                 // GPIO4(9)
+)
+
+const (
+	//                   [Pad]:      Alt Func 0       Alt Func 1       Alt Func 2           Alt Func 3            Alt Func 4            Alt Func 5   Alt Func 6            Alt Func 7            Alt Func 8             Alt Func 9
+	//                   ----------  ---------------  ---------------  -------------------  --------------------  --------------------  -----------  --------------------  --------------------  ---------------------  ----------------
+	PA0  = portA + 0  // [AD_B0_00]: FLEXPWM2_PWMA03  XBAR1_INOUT14    REF_CLK_32K          USB_OTG2_ID           LPI2C1_SCLS           GPIO1_IO00   USDHC1_RESET_B        LPSPI3_SCK             ~                      ~
+	PA1  = portA + 1  // [AD_B0_01]: FLEXPWM2_PWMB03  XBAR1_INOUT15    REF_CLK_24M          USB_OTG1_ID           LPI2C1_SDAS           GPIO1_IO01   EWM_OUT_B             LPSPI3_SDO             ~                      ~
+	PA2  = portA + 2  // [AD_B0_02]: FLEXCAN2_TX      XBAR1_INOUT16    LPUART6_TX           USB_OTG1_PWR          FLEXPWM1_PWMX00       GPIO1_IO02   LPI2C1_HREQ           LPSPI3_SDI             ~                      ~
+	PA3  = portA + 3  // [AD_B0_03]: FLEXCAN2_RX      XBAR1_INOUT17    LPUART6_RX           USB_OTG1_OC           FLEXPWM1_PWMX01       GPIO1_IO03   REF_CLK_24M           LPSPI3_PCS0            ~                      ~
+	PA4  = portA + 4  // [AD_B0_04]: SRC_BOOT_MODE00  MQS_RIGHT        ENET_TX_DATA03       SAI2_TX_SYNC          CSI_DATA09            GPIO1_IO04   PIT_TRIGGER00         LPSPI3_PCS1            ~                      ~
+	PA5  = portA + 5  // [AD_B0_05]: SRC_BOOT_MODE01  MQS_LEFT         ENET_TX_DATA02       SAI2_TX_BCLK          CSI_DATA08            GPIO1_IO05   XBAR1_INOUT17         LPSPI3_PCS2            ~                      ~
+	PA6  = portA + 6  // [AD_B0_06]: JTAG_TMS         GPT2_COMPARE1    ENET_RX_CLK          SAI2_RX_BCLK          CSI_DATA07            GPIO1_IO06   XBAR1_INOUT18         LPSPI3_PCS3            ~                      ~
+	PA7  = portA + 7  // [AD_B0_07]: JTAG_TCK         GPT2_COMPARE2    ENET_TX_ER           SAI2_RX_SYNC          CSI_DATA06            GPIO1_IO07   XBAR1_INOUT19         ENET_1588_EVENT3_OUT   ~                      ~
+	PA8  = portA + 8  // [AD_B0_08]: JTAG_MOD         GPT2_COMPARE3    ENET_RX_DATA03       SAI2_RX_DATA          CSI_DATA05            GPIO1_IO08   XBAR1_IN20            ENET_1588_EVENT3_IN    ~                      ~
+	PA9  = portA + 9  // [AD_B0_09]: JTAG_TDI         FLEXPWM2_PWMA03  ENET_RX_DATA02       SAI2_TX_DATA          CSI_DATA04            GPIO1_IO09   XBAR1_IN21            GPT2_CLK              SEMC_DQS4               ~
+	PA10 = portA + 10 // [AD_B0_10]: JTAG_TDO         FLEXPWM1_PWMA03  ENET_CRS             SAI2_MCLK             CSI_DATA03            GPIO1_IO10   XBAR1_IN22            ENET_1588_EVENT0_OUT  FLEXCAN3_TX            ARM_TRACE_SWO
+	PA11 = portA + 11 // [AD_B0_11]: JTAG_TRSTB       FLEXPWM1_PWMB03  ENET_COL             WDOG1_WDOG_B          CSI_DATA02            GPIO1_IO11   XBAR1_IN23            ENET_1588_EVENT0_IN   FLEXCAN3_RX            SEMC_CLK6
+	PA12 = portA + 12 // [AD_B0_12]: LPI2C4_SCL       CCM_PMIC_READY   LPUART1_TX           WDOG2_WDOG_B          FLEXPWM1_PWMX02       GPIO1_IO12   ENET_1588_EVENT1_OUT  NMI_GLUE_NMI           ~                      ~
+	PA13 = portA + 13 // [AD_B0_13]: LPI2C4_SDA       GPT1_CLK         LPUART1_RX           EWM_OUT_B             FLEXPWM1_PWMX03       GPIO1_IO13   ENET_1588_EVENT1_IN   REF_CLK_24M            ~                      ~
+	PA14 = portA + 14 // [AD_B0_14]: USB_OTG2_OC      XBAR1_IN24       LPUART1_CTS_B        ENET_1588_EVENT0_OUT  CSI_VSYNC             GPIO1_IO14   FLEXCAN2_TX           FLEXCAN3_TX            ~                      ~
+	PA15 = portA + 15 // [AD_B0_15]: USB_OTG2_PWR     XBAR1_IN25       LPUART1_RTS_B        ENET_1588_EVENT0_IN   CSI_HSYNC             GPIO1_IO15   FLEXCAN2_RX           WDOG1_WDOG_RST_B_DEB  FLEXCAN3_RX             ~
+	PA16 = portA + 16 // [AD_B1_00]: USB_OTG2_ID      QTIMER3_TIMER0   LPUART2_CTS_B        LPI2C1_SCL            WDOG1_B               GPIO1_IO16   USDHC1_WP             KPP_ROW07             ENET2_1588_EVENT0_OUT  FLEXIO3_FLEXIO00
+	PA17 = portA + 17 // [AD_B1_01]: USB_OTG1_PWR     QTIMER3_TIMER1   LPUART2_RTS_B        LPI2C1_SDA            CCM_PMIC_READY        GPIO1_IO17   USDHC1_VSELECT        KPP_COL07             ENET2_1588_EVENT0_IN   FLEXIO3_FLEXIO01
+	PA18 = portA + 18 // [AD_B1_02]: USB_OTG1_ID      QTIMER3_TIMER2   LPUART2_TX           SPDIF_OUT             ENET_1588_EVENT2_OUT  GPIO1_IO18   USDHC1_CD_B           KPP_ROW06             GPT2_CLK               FLEXIO3_FLEXIO02
+	PA19 = portA + 19 // [AD_B1_03]: USB_OTG1_OC      QTIMER3_TIMER3   LPUART2_RX           SPDIF_IN              ENET_1588_EVENT2_IN   GPIO1_IO19   USDHC2_CD_B           KPP_COL06             GPT2_CAPTURE1          FLEXIO3_FLEXIO03
+	PA20 = portA + 20 // [AD_B1_04]: FLEXSPIB_DATA03  ENET_MDC         LPUART3_CTS_B        SPDIF_SR_CLK          CSI_PIXCLK            GPIO1_IO20   USDHC2_DATA0          KPP_ROW05             GPT2_CAPTURE2          FLEXIO3_FLEXIO04
+	PA21 = portA + 21 // [AD_B1_05]: FLEXSPIB_DATA02  ENET_MDIO        LPUART3_RTS_B        SPDIF_OUT             CSI_MCLK              GPIO1_IO21   USDHC2_DATA1          KPP_COL05             GPT2_COMPARE1          FLEXIO3_FLEXIO05
+	PA22 = portA + 22 // [AD_B1_06]: FLEXSPIB_DATA01  LPI2C3_SDA       LPUART3_TX           SPDIF_LOCK            CSI_VSYNC             GPIO1_IO22   USDHC2_DATA2          KPP_ROW04             GPT2_COMPARE2          FLEXIO3_FLEXIO06
+	PA23 = portA + 23 // [AD_B1_07]: FLEXSPIB_DATA00  LPI2C3_SCL       LPUART3_RX           SPDIF_EXT_CLK         CSI_HSYNC             GPIO1_IO23   USDHC2_DATA3          KPP_COL04             GPT2_COMPARE3          FLEXIO3_FLEXIO07
+	PA24 = portA + 24 // [AD_B1_08]: FLEXSPIA_SS1_B   FLEXPWM4_PWMA00  FLEXCAN1_TX          CCM_PMIC_READY        CSI_DATA09            GPIO1_IO24   USDHC2_CMD            KPP_ROW03             FLEXIO3_FLEXIO08        ~
+	PA25 = portA + 25 // [AD_B1_09]: FLEXSPIA_DQS     FLEXPWM4_PWMA01  FLEXCAN1_RX          SAI1_MCLK             CSI_DATA08            GPIO1_IO25   USDHC2_CLK            KPP_COL03             FLEXIO3_FLEXIO09        ~
+	PA26 = portA + 26 // [AD_B1_10]: FLEXSPIA_DATA03  WDOG1_B          LPUART8_TX           SAI1_RX_SYNC          CSI_DATA07            GPIO1_IO26   USDHC2_WP             KPP_ROW02             ENET2_1588_EVENT1_OUT  FLEXIO3_FLEXIO10
+	PA27 = portA + 27 // [AD_B1_11]: FLEXSPIA_DATA02  EWM_OUT_B        LPUART8_RX           SAI1_RX_BCLK          CSI_DATA06            GPIO1_IO27   USDHC2_RESET_B        KPP_COL02             ENET2_1588_EVENT1_IN   FLEXIO3_FLEXIO11
+	PA28 = portA + 28 // [AD_B1_12]: FLEXSPIA_DATA01  ACMP_OUT00       LPSPI3_PCS0          SAI1_RX_DATA00        CSI_DATA05            GPIO1_IO28   USDHC2_DATA4          KPP_ROW01             ENET2_1588_EVENT2_OUT  FLEXIO3_FLEXIO12
+	PA29 = portA + 29 // [AD_B1_13]: FLEXSPIA_DATA00  ACMP_OUT01       LPSPI3_SDI           SAI1_TX_DATA00        CSI_DATA04            GPIO1_IO29   USDHC2_DATA5          KPP_COL01             ENET2_1588_EVENT2_IN   FLEXIO3_FLEXIO13
+	PA30 = portA + 30 // [AD_B1_14]: FLEXSPIA_SCLK    ACMP_OUT02       LPSPI3_SDO           SAI1_TX_BCLK          CSI_DATA03            GPIO1_IO30   USDHC2_DATA6          KPP_ROW00             ENET2_1588_EVENT3_OUT  FLEXIO3_FLEXIO14
+	PA31 = portA + 31 // [AD_B1_15]: FLEXSPIA_SS0_B   ACMP_OUT03       LPSPI3_SCK           SAI1_TX_SYNC          CSI_DATA02            GPIO1_IO31   USDHC2_DATA7          KPP_COL00             ENET2_1588_EVENT3_IN   FLEXIO3_FLEXIO15
+
+	PB0  = portB + 0  // [B0_00]:    LCD_CLK          QTIMER1_TIMER0   MQS_RIGHT            LPSPI4_PCS0           FLEXIO2_FLEXIO00      GPIO2_IO00   SEMC_CSX01            ENET2_MDC              ~                      ~
+	PB1  = portB + 1  // [B0_01]:    LCD_ENABLE       QTIMER1_TIMER1   MQS_LEFT             LPSPI4_SDI            FLEXIO2_FLEXIO01      GPIO2_IO01   SEMC_CSX02            ENET2_MDIO             ~                      ~
+	PB2  = portB + 2  // [B0_02]:    LCD_HSYNC        QTIMER1_TIMER2   FLEXCAN1_TX          LPSPI4_SDO            FLEXIO2_FLEXIO02      GPIO2_IO02   SEMC_CSX03            ENET2_1588_EVENT0_OUT  ~                      ~
+	PB3  = portB + 3  // [B0_03]:    LCD_VSYNC        QTIMER2_TIMER0   FLEXCAN1_RX          LPSPI4_SCK            FLEXIO2_FLEXIO03      GPIO2_IO03   WDOG2_RESET_B_DEB     ENET2_1588_EVENT0_IN   ~                      ~
+	PB4  = portB + 4  // [B0_04]:    LCD_DATA00       QTIMER2_TIMER1   LPI2C2_SCL           ARM_TRACE0            FLEXIO2_FLEXIO04      GPIO2_IO04   SRC_BOOT_CFG00        ENET2_TDATA03          ~                      ~
+	PB5  = portB + 5  // [B0_05]:    LCD_DATA01       QTIMER2_TIMER2   LPI2C2_SDA           ARM_TRACE1            FLEXIO2_FLEXIO05      GPIO2_IO05   SRC_BOOT_CFG01        ENET2_TDATA02          ~                      ~
+	PB6  = portB + 6  // [B0_06]:    LCD_DATA02       QTIMER3_TIMER0   FLEXPWM2_PWMA00      ARM_TRACE2            FLEXIO2_FLEXIO06      GPIO2_IO06   SRC_BOOT_CFG02        ENET2_RX_CLK           ~                      ~
+	PB7  = portB + 7  // [B0_07]:    LCD_DATA03       QTIMER3_TIMER1   FLEXPWM2_PWMB00      ARM_TRACE3            FLEXIO2_FLEXIO07      GPIO2_IO07   SRC_BOOT_CFG03        ENET2_TX_ER            ~                      ~
+	PB8  = portB + 8  // [B0_08]:    LCD_DATA04       QTIMER3_TIMER2   FLEXPWM2_PWMA01      LPUART3_TX            FLEXIO2_FLEXIO08      GPIO2_IO08   SRC_BOOT_CFG04        ENET2_RDATA03          ~                      ~
+	PB9  = portB + 9  // [B0_09]:    LCD_DATA05       QTIMER4_TIMER0   FLEXPWM2_PWMB01      LPUART3_RX            FLEXIO2_FLEXIO09      GPIO2_IO09   SRC_BOOT_CFG05        ENET2_RDATA02          ~                      ~
+	PB10 = portB + 10 // [B0_10]:    LCD_DATA06       QTIMER4_TIMER1   FLEXPWM2_PWMA02      SAI1_TX_DATA03        FLEXIO2_FLEXIO10      GPIO2_IO10   SRC_BOOT_CFG06        ENET2_CRS              ~                      ~
+	PB11 = portB + 11 // [B0_11]:    LCD_DATA07       QTIMER4_TIMER2   FLEXPWM2_PWMB02      SAI1_TX_DATA02        FLEXIO2_FLEXIO11      GPIO2_IO11   SRC_BOOT_CFG07        ENET2_COL              ~                      ~
+	PB12 = portB + 12 // [B0_12]:    LCD_DATA08       XBAR1_INOUT10    ARM_TRACE_CLK        SAI1_TX_DATA01        FLEXIO2_FLEXIO12      GPIO2_IO12   SRC_BOOT_CFG08        ENET2_TDATA00          ~                      ~
+	PB13 = portB + 13 // [B0_13]:    LCD_DATA09       XBAR1_INOUT11    ARM_TRACE_SWO        SAI1_MCLK             FLEXIO2_FLEXIO13      GPIO2_IO13   SRC_BOOT_CFG09        ENET2_TDATA01          ~                      ~
+	PB14 = portB + 14 // [B0_14]:    LCD_DATA10       XBAR1_INOUT12    ARM_TXEV             SAI1_RX_SYNC          FLEXIO2_FLEXIO14      GPIO2_IO14   SRC_BOOT_CFG10        ENET2_TX_EN            ~                      ~
+	PB15 = portB + 15 // [B0_15]:    LCD_DATA11       XBAR1_INOUT13    ARM_RXEV             SAI1_RX_BCLK          FLEXIO2_FLEXIO15      GPIO2_IO15   SRC_BOOT_CFG11        ENET2_TX_CLK          ENET2_REF_CLK2          ~
+	PB16 = portB + 16 // [B1_00]:    LCD_DATA12       XBAR1_INOUT14    LPUART4_TX           SAI1_RX_DATA00        FLEXIO2_FLEXIO16      GPIO2_IO16   FLEXPWM1_PWMA03       ENET2_RX_ER           FLEXIO3_FLEXIO16        ~
+	PB17 = portB + 17 // [B1_01]:    LCD_DATA13       XBAR1_INOUT15    LPUART4_RX           SAI1_TX_DATA00        FLEXIO2_FLEXIO17      GPIO2_IO17   FLEXPWM1_PWMB03       ENET2_RDATA00         FLEXIO3_FLEXIO17        ~
+	PB18 = portB + 18 // [B1_02]:    LCD_DATA14       XBAR1_INOUT16    LPSPI4_PCS2          SAI1_TX_BCLK          FLEXIO2_FLEXIO18      GPIO2_IO18   FLEXPWM2_PWMA03       ENET2_RDATA01         FLEXIO3_FLEXIO18        ~
+	PB19 = portB + 19 // [B1_03]:    LCD_DATA15       XBAR1_INOUT17    LPSPI4_PCS1          SAI1_TX_SYNC          FLEXIO2_FLEXIO19      GPIO2_IO19   FLEXPWM2_PWMB03       ENET2_RX_EN           FLEXIO3_FLEXIO19        ~
+	PB20 = portB + 20 // [B1_04]:    LCD_DATA16       LPSPI4_PCS0      CSI_DATA15           ENET_RX_DATA00        FLEXIO2_FLEXIO20      GPIO2_IO20   GPT1_CLK              FLEXIO3_FLEXIO20       ~                      ~
+	PB21 = portB + 21 // [B1_05]:    LCD_DATA17       LPSPI4_SDI       CSI_DATA14           ENET_RX_DATA01        FLEXIO2_FLEXIO21      GPIO2_IO21   GPT1_CAPTURE1         FLEXIO3_FLEXIO21       ~                      ~
+	PB22 = portB + 22 // [B1_06]:    LCD_DATA18       LPSPI4_SDO       CSI_DATA13           ENET_RX_EN            FLEXIO2_FLEXIO22      GPIO2_IO22   GPT1_CAPTURE2         FLEXIO3_FLEXIO22       ~                      ~
+	PB23 = portB + 23 // [B1_07]:    LCD_DATA19       LPSPI4_SCK       CSI_DATA12           ENET_TX_DATA00        FLEXIO2_FLEXIO23      GPIO2_IO23   GPT1_COMPARE1         FLEXIO3_FLEXIO23       ~                      ~
+	PB24 = portB + 24 // [B1_08]:    LCD_DATA20       QTIMER1_TIMER3   CSI_DATA11           ENET_TX_DATA01        FLEXIO2_FLEXIO24      GPIO2_IO24   FLEXCAN2_TX           GPT1_COMPARE2         FLEXIO3_FLEXIO24        ~
+	PB25 = portB + 25 // [B1_09]:    LCD_DATA21       QTIMER2_TIMER3   CSI_DATA10           ENET_TX_EN            FLEXIO2_FLEXIO25      GPIO2_IO25   FLEXCAN2_RX           GPT1_COMPARE3         FLEXIO3_FLEXIO25        ~
+	PB26 = portB + 26 // [B1_10]:    LCD_DATA22       QTIMER3_TIMER3   CSI_DATA00           ENET_TX_CLK           FLEXIO2_FLEXIO26      GPIO2_IO26   ENET_REF_CLK          FLEXIO3_FLEXIO26       ~                      ~
+	PB27 = portB + 27 // [B1_11]:    LCD_DATA23       QTIMER4_TIMER3   CSI_DATA01           ENET_RX_ER            FLEXIO2_FLEXIO27      GPIO2_IO27   LPSPI4_PCS3           FLEXIO3_FLEXIO27       ~                      ~
+	PB28 = portB + 28 // [B1_12]:    LPUART5_TX       CSI_PIXCLK       ENET_1588_EVENT0_IN  FLEXIO2_FLEXIO28      GPIO2_IO28            USDHC1_CD_B  FLEXIO3_FLEXIO28       ~                     ~                      ~
+	PB29 = portB + 29 // [B1_13]:    WDOG1_B          LPUART5_RX       CSI_VSYNC            ENET_1588_EVENT0_OUT  FLEXIO2_FLEXIO29      GPIO2_IO29   USDHC1_WP             SEMC_DQS4             FLEXIO3_FLEXIO29        ~
+	PB30 = portB + 30 // [B1_14]:    ENET_MDC         FLEXPWM4_PWMA02  CSI_HSYNC            XBAR1_IN02            FLEXIO2_FLEXIO30      GPIO2_IO30   USDHC1_VSELECT        ENET2_TDATA00         FLEXIO3_FLEXIO30        ~
+	PB31 = portB + 31 // [B1_15]:    ENET_MDIO        FLEXPWM4_PWMA03  CSI_MCLK             XBAR1_IN03            FLEXIO2_FLEXIO31      GPIO2_IO31   USDHC1_RESET_B        ENET2_TDATA01         FLEXIO3_FLEXIO31        ~
+
+	PC0  = portC + 0  // [SD_B1_00]: USDHC2_DATA3     FLEXSPIB_DATA03  FLEXPWM1_PWMA03      SAI1_TX_DATA03        LPUART4_TX            GPIO3_IO00   SAI3_RX_DATA           ~                     ~                      ~
+	PC1  = portC + 1  // [SD_B1_01]: USDHC2_DATA2     FLEXSPIB_DATA02  FLEXPWM1_PWMB03      SAI1_TX_DATA02        LPUART4_RX            GPIO3_IO01   SAI3_TX_DATA           ~                     ~                      ~
+	PC2  = portC + 2  // [SD_B1_02]: USDHC2_DATA1     FLEXSPIB_DATA01  FLEXPWM2_PWMA03      SAI1_TX_DATA01        FLEXCAN1_TX           GPIO3_IO02   CCM_WAIT              SAI3_TX_SYNC           ~                      ~
+	PC3  = portC + 3  // [SD_B1_03]: USDHC2_DATA0     FLEXSPIB_DATA00  FLEXPWM2_PWMB03      SAI1_MCLK             FLEXCAN1_RX           GPIO3_IO03   CCM_PMIC_READY        SAI3_TX_BCLK           ~                      ~
+	PC4  = portC + 4  // [SD_B1_04]: USDHC2_CLK       FLEXSPIB_SCLK    LPI2C1_SCL           SAI1_RX_SYNC          FLEXSPIA_SS1_B        GPIO3_IO04   CCM_STOP              SAI3_MCLK              ~                      ~
+	PC5  = portC + 5  // [SD_B1_05]: USDHC2_CMD       FLEXSPIA_DQS     LPI2C1_SDA           SAI1_RX_BCLK          FLEXSPIB_SS0_B        GPIO3_IO05   SAI3_RX_SYNC           ~                     ~                      ~
+	PC6  = portC + 6  // [SD_B1_06]: USDHC2_RESET_B   FLEXSPIA_SS0_B   LPUART7_CTS_B        SAI1_RX_DATA00        LPSPI2_PCS0           GPIO3_IO06   SAI3_RX_BCLK           ~                     ~                      ~
+	PC7  = portC + 7  // [SD_B1_07]: SEMC_CSX01       FLEXSPIA_SCLK    LPUART7_RTS_B        SAI1_TX_DATA00        LPSPI2_SCK            GPIO3_IO07    ~                     ~                     ~                      ~
+	PC8  = portC + 8  // [SD_B1_08]: USDHC2_DATA4     FLEXSPIA_DATA00  LPUART7_TX           SAI1_TX_BCLK          LPSPI2_SD0            GPIO3_IO08   SEMC_CSX02             ~                     ~                      ~
+	PC9  = portC + 9  // [SD_B1_09]: USDHC2_DATA5     FLEXSPIA_DATA01  LPUART7_RX           SAI1_TX_SYNC          LPSPI2_SDI            GPIO3_IO09    ~                     ~                     ~                      ~
+	PC10 = portC + 10 // [SD_B1_10]: USDHC2_DATA6     FLEXSPIA_DATA02  LPUART2_RX           LPI2C2_SDA            LPSPI2_PCS2           GPIO3_IO10    ~                     ~                     ~                      ~
+	PC11 = portC + 11 // [SD_B1_11]: USDHC2_DATA7     FLEXSPIA_DATA03  LPUART2_TX           LPI2C2_SCL            LPSPI2_PCS3           GPIO3_IO11    ~                     ~                     ~                      ~
+	PC12 = portC + 12 // [SD_B0_00]: USDHC1_CMD       FLEXPWM1_PWMA00  LPI2C3_SCL           XBAR1_INOUT04         LPSPI1_SCK            GPIO3_IO12   FLEXSPIA_SS1_B        ENET2_TX_EN           SEMC_DQS4               ~
+	PC13 = portC + 13 // [SD_B0_01]: USDHC1_CLK       FLEXPWM1_PWMB00  LPI2C3_SDA           XBAR1_INOUT05         LPSPI1_PCS0           GPIO3_IO13   FLEXSPIB_SS1_B        ENET2_TX_CLK          ENET2_REF_CLK2          ~
+	PC14 = portC + 14 // [SD_B0_02]: USDHC1_DATA0     FLEXPWM1_PWMA01  LPUART8_CTS_B        XBAR1_INOUT06         LPSPI1_SDO            GPIO3_IO14   ENET2_RX_ER           SEMC_CLK5              ~                      ~
+	PC15 = portC + 15 // [SD_B0_03]: USDHC1_DATA1     FLEXPWM1_PWMB01  LPUART8_RTS_B        XBAR1_INOUT07         LPSPI1_SDI            GPIO3_IO15   ENET2_RDATA00         SEMC_CLK6              ~                      ~
+	PC16 = portC + 16 // [SD_B0_04]: USDHC1_DATA2     FLEXPWM1_PWMA02  LPUART8_TX           XBAR1_INOUT08         FLEXSPIB_SS0_B        GPIO3_IO16   CCM_CLKO1             ENET2_RDATA01          ~                      ~
+	PC17 = portC + 17 // [SD_B0_05]: USDHC1_DATA3     FLEXPWM1_PWMB02  LPUART8_RX           XBAR1_INOUT09         FLEXSPIB_DQS          GPIO3_IO17   CCM_CLKO2             ENET2_RX_EN            ~                      ~
+	PC18 = portC + 18 // [EMC_32]:   SEMC_DATA10      FLEXPWM3_PWMB01  LPUART7_RX           CCM_PMIC_RDY          CSI_DATA21            GPIO3_IO18   ENET2_TX_EN            ~                     ~                      ~
+	PC19 = portC + 19 // [EMC_33]:   SEMC_DATA11      FLEXPWM3_PWMA02  USDHC1_RESET_B       SAI3_RX_DATA          CSI_DATA20            GPIO3_IO19   ENET2_TX_CLK          ENET2_REF_CLK2         ~                      ~
+	PC20 = portC + 20 // [EMC_34]:   SEMC_DATA12      FLEXPWM3_PWMB02  USDHC1_VSELECT       SAI3_RX_SYNC          CSI_DATA19            GPIO3_IO20   ENET2_RX_ER            ~                     ~                      ~
+	PC21 = portC + 21 // [EMC_35]:   SEMC_DATA13      XBAR1_INOUT18    GPT1_COMPARE1        SAI3_RX_BCLK          CSI_DATA18            GPIO3_IO21   USDHC1_CD_B           ENET2_RDATA00          ~                      ~
+	PC22 = portC + 22 // [EMC_36]:   SEMC_DATA14      XBAR1_IN22       GPT1_COMPARE2        SAI3_TX_DATA          CSI_DATA17            GPIO3_IO22   USDHC1_WP             ENET2_RDATA01         FLEXCAN3_TX             ~
+	PC23 = portC + 23 // [EMC_37]:   SEMC_DATA15      XBAR1_IN23       GPT1_COMPARE3        SAI3_MCLK             CSI_DATA16            GPIO3_IO23   USDHC2_WP             ENET2_RX_EN           FLEXCAN3_RX             ~
+	PC24 = portC + 24 // [EMC_38]:   SEMC_DM01        FLEXPWM1_PWMA03  LPUART8_TX           SAI3_TX_BCLK          CSI_FIELD             GPIO3_IO24   USDHC2_VSELECT        ENET2_MDC              ~                      ~
+	PC25 = portC + 25 // [EMC_39]:   SEMC_DQS         FLEXPWM1_PWMB03  LPUART8_RX           SAI3_TX_SYNC          WDOG1_WDOG_B          GPIO3_IO25   USDHC2_CD_B           ENET2_MDIO            SEMC_DQS4               ~
+	PC26 = portC + 26 // [EMC_40]:   SEMC_RDY         GPT2_CAPTURE2    LPSPI1_PCS2          USB_OTG2_OC           ENET_MDC              GPIO3_IO26   USDHC2_RESET_B        SEMC_CLK5              ~                      ~
+	PC27 = portC + 27 // [EMC_41]:   SEMC_CSX00       GPT2_CAPTURE1    LPSPI1_PCS3          USB_OTG2_PWR          ENET_MDIO             GPIO3_IO27   USDHC1_VSELECT         ~                     ~                      ~
+	_    = portC + 28 //
+	_    = portC + 29 //
+	_    = portC + 30 //
+	_    = portC + 31 //
+
+	PD0  = portD + 0  // [EMC_00]:   SEMC_DATA00      FLEXPWM4_PWMA00  LPSPI2_SCK           XBAR1_XBAR_IN02       FLEXIO1_FLEXIO00      GPIO4_IO00    ~                     ~                     ~                      ~
+	PD1  = portD + 1  // [EMC_01]:   SEMC_DATA01      FLEXPWM4_PWMB00  LPSPI2_PCS0          XBAR1_IN03            FLEXIO1_FLEXIO01      GPIO4_IO01    ~                     ~                     ~                      ~
+	PD2  = portD + 2  // [EMC_02]:   SEMC_DATA02      FLEXPWM4_PWMA01  LPSPI2_SDO           XBAR1_INOUT04         FLEXIO1_FLEXIO02      GPIO4_IO02    ~                     ~                     ~                      ~
+	PD3  = portD + 3  // [EMC_03]:   SEMC_DATA03      FLEXPWM4_PWMB01  LPSPI2_SDI           XBAR1_INOUT05         FLEXIO1_FLEXIO03      GPIO4_IO03    ~                     ~                     ~                      ~
+	PD4  = portD + 4  // [EMC_04]:   SEMC_DATA04      FLEXPWM4_PWMA02  SAI2_TX_DATA         XBAR1_INOUT06         FLEXIO1_FLEXIO04      GPIO4_IO04    ~                     ~                     ~                      ~
+	PD5  = portD + 5  // [EMC_05]:   SEMC_DATA05      FLEXPWM4_PWMB02  SAI2_TX_SYNC         XBAR1_INOUT07         FLEXIO1_FLEXIO05      GPIO4_IO05    ~                     ~                     ~                      ~
+	PD6  = portD + 6  // [EMC_06]:   SEMC_DATA06      FLEXPWM2_PWMA00  SAI2_TX_BCLK         XBAR1_INOUT08         FLEXIO1_FLEXIO06      GPIO4_IO06    ~                     ~                     ~                      ~
+	PD7  = portD + 7  // [EMC_07]:   SEMC_DATA07      FLEXPWM2_PWMB00  SAI2_MCLK            XBAR1_INOUT09         FLEXIO1_FLEXIO07      GPIO4_IO07    ~                     ~                     ~                      ~
+	PD8  = portD + 8  // [EMC_08]:   SEMC_DM00        FLEXPWM2_PWMA01  SAI2_RX_DATA         XBAR1_INOUT17         FLEXIO1_FLEXIO08      GPIO4_IO08    ~                     ~                     ~                      ~
+	PD9  = portD + 9  // [EMC_09]:   SEMC_ADDR00      FLEXPWM2_PWMB01  SAI2_RX_SYNC         FLEXCAN2_TX           FLEXIO1_FLEXIO09      GPIO4_IO09   FLEXSPI2_B_SS1_B       ~                     ~                      ~
+	PD10 = portD + 10 // [EMC_10]:   SEMC_ADDR01      FLEXPWM2_PWMA02  SAI2_RX_BCLK         FLEXCAN2_RX           FLEXIO1_FLEXIO10      GPIO4_IO10   FLEXSPI2_B_SS0_B       ~                     ~                      ~
+	PD11 = portD + 11 // [EMC_11]:   SEMC_ADDR02      FLEXPWM2_PWMB02  LPI2C4_SDA           USDHC2_RESET_B        FLEXIO1_FLEXIO11      GPIO4_IO11   FLEXSPI2_B_DQS         ~                     ~                      ~
+	PD12 = portD + 12 // [EMC_12]:   SEMC_ADDR03      XBAR1_IN24       LPI2C4_SCL           USDHC1_WP             FLEXPWM1_PWMA03       GPIO4_IO12   FLEXSPI2_B_SCLK        ~                     ~                      ~
+	PD13 = portD + 13 // [EMC_13]:   SEMC_ADDR04      XBAR1_IN25       LPUART3_TX           MQS_RIGHT             FLEXPWM1_PWMB03       GPIO4_IO13   FLEXSPI2_B_DATA00      ~                     ~                      ~
+	PD14 = portD + 14 // [EMC_14]:   SEMC_ADDR05      XBAR1_INOUT19    LPUART3_RX           MQS_LEFT              LPSPI2_PCS1           GPIO4_IO14   FLEXSPI2_B_DATA01      ~                     ~                      ~
+	PD15 = portD + 15 // [EMC_15]:   SEMC_ADDR06      XBAR1_IN20       LPUART3_CTS_B        SPDIF_OUT             QTIMER3_TIMER0        GPIO4_IO15   FLEXSPI2_B_DATA02      ~                     ~                      ~
+	PD16 = portD + 16 // [EMC_16]:   SEMC_ADDR07      XBAR1_IN21       LPUART3_RTS_B        SPDIF_IN              QTIMER3_TIMER1        GPIO4_IO16   FLEXSPI2_B_DATA03      ~                     ~                      ~
+	PD17 = portD + 17 // [EMC_17]:   SEMC_ADDR08      FLEXPWM4_PWMA03  LPUART4_CTS_B        FLEXCAN1_TX           QTIMER3_TIMER2        GPIO4_IO17    ~                     ~                     ~                      ~
+	PD18 = portD + 18 // [EMC_18]:   SEMC_ADDR09      FLEXPWM4_PWMB03  LPUART4_RTS_B        FLEXCAN1_RX           QTIMER3_TIMER3        GPIO4_IO18   SNVS_VIO_5_CTL         ~                     ~                      ~
+	PD19 = portD + 19 // [EMC_19]:   SEMC_ADDR11      FLEXPWM2_PWMA03  LPUART4_TX           ENET_RDATA01          QTIMER2_TIMER0        GPIO4_IO19   SNVS_VIO_5             ~                     ~                      ~
+	PD20 = portD + 20 // [EMC_20]:   SEMC_ADDR12      FLEXPWM2_PWMB03  LPUART4_RX           ENET_RDATA00          QTIMER2_TIMER1        GPIO4_IO20    ~                     ~                     ~                      ~
+	PD21 = portD + 21 // [EMC_21]:   SEMC_BA0         FLEXPWM3_PWMA03  LPI2C3_SDA           ENET_TDATA01          QTIMER2_TIMER2        GPIO4_IO21    ~                     ~                     ~                      ~
+	PD22 = portD + 22 // [EMC_22]:   SEMC_BA1         FLEXPWM3_PWMB03  LPI2C3_SCL           ENET_TDATA00          QTIMER2_TIMER3        GPIO4_IO22   FLEXSPI2_A_SS1_B       ~                     ~                      ~
+	PD23 = portD + 23 // [EMC_23]:   SEMC_ADDR10      FLEXPWM1_PWMA00  LPUART5_TX           ENET_RX_EN            GPT1_CAPTURE2         GPIO4_IO23   FLEXSPI2_A_DQS         ~                     ~                      ~
+	PD24 = portD + 24 // [EMC_24]:   SEMC_CAS         FLEXPWM1_PWMB00  LPUART5_RX           ENET_TX_EN            GPT1_CAPTURE1         GPIO4_IO24   FLEXSPI2_A_SS0_B       ~                     ~                      ~
+	PD25 = portD + 25 // [EMC_25]:   SEMC_RAS         FLEXPWM1_PWMA01  LPUART6_TX           ENET_TX_CLK           ENET_REF_CLK          GPIO4_IO25   FLEXSPI2_A_SCLK        ~                     ~                      ~
+	PD26 = portD + 26 // [EMC_26]:   SEMC_CLK         FLEXPWM1_PWMB01  LPUART6_RX           ENET_RX_ER            FLEXIO1_FLEXIO12      GPIO4_IO26   FLEXSPI2_A_DATA00      ~                     ~                      ~
+	PD27 = portD + 27 // [EMC_27]:   SEMC_CKE         FLEXPWM1_PWMA02  LPUART5_RTS_B        LPSPI1_SCK            FLEXIO1_FLEXIO13      GPIO4_IO27   FLEXSPI2_A_DATA01      ~                     ~                      ~
+	PD28 = portD + 28 // [EMC_28]:   SEMC_WE          FLEXPWM1_PWMB02  LPUART5_CTS_B        LPSPI1_SDO            FLEXIO1_FLEXIO14      GPIO4_IO28   FLEXSPI2_A_DATA02      ~                     ~                      ~
+	PD29 = portD + 29 // [EMC_29]:   SEMC_CS0         FLEXPWM3_PWMA00  LPUART6_RTS_B        LPSPI1_SDI            FLEXIO1_FLEXIO15      GPIO4_IO29   FLEXSPI2_A_DATA03      ~                     ~                      ~
+	PD30 = portD + 30 // [EMC_30]:   SEMC_DATA08      FLEXPWM3_PWMB00  LPUART6_CTS_B        LPSPI1_PCS0           CSI_DATA23            GPIO4_IO30   ENET2_TDATA00          ~                     ~                      ~
+	PD31 = portD + 31 // [EMC_31]:   SEMC_DATA09      FLEXPWM3_PWMA01  LPUART7_TX           LPSPI1_PCS1           CSI_DATA22            GPIO4_IO31   ENET2_TDATA01          ~                     ~                      ~
+)
+
+func (p Pin) getPos() uint8   { return uint8(p % 32) }
+func (p Pin) getMask() uint32 { return uint32(1) << p.getPos() }
+func (p Pin) getPort() Pin    { return Pin(p/32) * 32 }
+
+// Configure sets the GPIO pad and pin properties, and selects the appropriate
+// alternate function, for a given Pin and PinConfig.
+func (p Pin) Configure(config PinConfig) {
+	var (
+		sre = uint32(0x01 << 0)
+		dse = func(n uint32) uint32 { return (n & 0x07) << 3 }
+		spd = func(n uint32) uint32 { return (n & 0x03) << 6 }
+		ode = uint32(0x01 << 11)
+		pke = uint32(0x01 << 12)
+		pue = uint32(0x01 << 13)
+		pup = func(n uint32) uint32 { return (n & 0x03) << 14 }
+		hys = uint32(0x01 << 16)
+	)
+
+	_, gpio := p.getGPIO() // use fast GPIO for all pins
+	pad, mux := p.getPad()
+
+	// first configure the pad characteristics
+	switch config.Mode {
+	case PinInput:
+		gpio.GDIR.ClearBits(p.getMask())
+		pad.Set(dse(7))
+
+	case PinInputPullUp:
+		gpio.GDIR.ClearBits(p.getMask())
+		pad.Set(dse(7) | pke | pue | pup(3) | hys)
+
+	case PinInputPullDown:
+		gpio.GDIR.ClearBits(p.getMask())
+		pad.Set(dse(7) | pke | pue | hys)
+
+	case PinOutput:
+		gpio.GDIR.SetBits(p.getMask())
+		pad.Set(dse(7))
+
+	case PinOutputOpenDrain:
+		gpio.GDIR.SetBits(p.getMask())
+		pad.Set(dse(7) | ode)
+
+	case PinDisable:
+		gpio.GDIR.ClearBits(p.getMask())
+		pad.Set(dse(7) | hys)
+
+	case PinInputAnalog:
+		gpio.GDIR.ClearBits(p.getMask())
+		pad.Set(dse(7))
+
+	case PinModeUARTTX:
+		pad.Set(sre | dse(3) | spd(3))
+
+	case PinModeUARTRX:
+		pad.Set(dse(7) | pke | pue | pup(3) | hys)
+
+	case PinModeSPISDI:
+		pad.Set(dse(7) | spd(2))
+
+	case PinModeSPISDO:
+		pad.Set(dse(7) | spd(2))
+
+	case PinModeSPICLK:
+		pad.Set(dse(7) | spd(2))
+
+	case PinModeSPICS:
+		pad.Set(dse(7))
+
+	case PinModeI2CSDA, PinModeI2CSCL:
+		pad.Set(ode | sre | dse(4) | spd(1) | pke | pue | pup(3))
+	}
+
+	// then configure the alternate function mux
+	mux.Set(p.getMuxMode(config))
+}
+
+// Get returns the current value of a GPIO pin.
+func (p Pin) Get() bool {
+	_, gpio := p.getGPIO() // use fast GPIO for all pins
+	return gpio.PSR.HasBits(p.getMask())
+}
+
+// Set changes the value of the GPIO pin. The pin must be configured as output.
+func (p Pin) Set(value bool) {
+	_, gpio := p.getGPIO() // use fast GPIO for all pins
+	if value {
+		gpio.DR_SET.Set(p.getMask())
+	} else {
+		gpio.DR_CLEAR.Set(p.getMask())
+	}
+}
+
+// Toggle switches an output pin from low to high or from high to low.
+func (p Pin) Toggle() {
+	_, gpio := p.getGPIO() // use fast GPIO for all pins
+	gpio.DR_TOGGLE.Set(p.getMask())
+}
+
+// dispatchInterrupt invokes the user-provided callback functions for external
+// interrupts generated on the high-speed GPIO pins.
+//
+// Unfortunately, all four high-speed GPIO ports (A-D) are connected to just a
+// single interrupt control line. Therefore, the interrupt status register (ISR)
+// must be checked in all four GPIO ports on every interrupt.
+func (jt *pinJumpTable) dispatchInterrupt(interrupt.Interrupt) {
+	handle := func(gpio *nxp.GPIO_Type, port Pin) {
+		if status := gpio.ISR.Get() & gpio.IMR.Get(); status != 0 {
+			gpio.ISR.Set(status) // clear interrupt
+			for status != 0 {
+				p := Pin(bits.TrailingZeros32(status))
+				i := Pin(port + p)
+				jt.lut[i](i)
+				status &^= 1 << p
+			}
+		}
+	}
+	if jt.numDefined > 0 {
+		handle(nxp.GPIO6, portA)
+		handle(nxp.GPIO7, portB)
+		handle(nxp.GPIO8, portC)
+		handle(nxp.GPIO9, portD)
+	}
+}
+
+// set associates a function with a given Pin in the receiver lookup table. If
+// the function is nil, the given Pin's associated function is removed.
+func (jt *pinJumpTable) set(pin Pin, fn func(Pin)) {
+	if int(pin) < len(jt.lut) {
+		if nil != fn {
+			if nil == jt.lut[pin] {
+				jt.numDefined++
+			}
+			jt.lut[pin] = fn
+		} else {
+			if nil != jt.lut[pin] {
+				jt.numDefined--
+			}
+			jt.lut[pin] = nil
+		}
+	}
+}
+
+// SetInterrupt sets an interrupt to be executed when a particular pin changes
+// state. The pin should already be configured as an input, including a pull up
+// or down if no external pull is provided.
+//
+// This call will replace a previously set callback on this pin. You can pass a
+// nil func to unset the pin change interrupt. If you do so, the change
+// parameter is ignored and can be set to any value (such as 0).
+func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) error {
+	_, gpio := p.getGPIO() // use fast GPIO for all pins
+	mask := p.getMask()
+	if nil != callback {
+		switch change {
+		case PinLow, PinHigh, PinRising, PinFalling:
+			gpio.EDGE_SEL.ClearBits(mask)
+			var reg *volatile.Register32
+			var pos uint8
+			if pos = p.getPos(); pos < 16 {
+				reg = &gpio.ICR1 // ICR1 = pins 0-15
+			} else {
+				reg = &gpio.ICR2 // ICR2 = pins 16-31
+				pos -= 16
+			}
+			reg.ReplaceBits(uint32(change), 0x3, pos*2)
+		case PinToggle:
+			gpio.EDGE_SEL.SetBits(mask)
+		}
+		pinISR.set(p, callback) // associate the callback with the pin
+		gpio.ISR.Set(mask)      // clear any pending interrupt (W1C)
+		gpio.IMR.SetBits(mask)  // enable external interrupt
+	} else {
+		pinISR.set(p, nil)       // remove any associated callback from the pin
+		gpio.ISR.Set(mask)       // clear any pending interrupt (W1C)
+		gpio.IMR.ClearBits(mask) // disable external interrupt
+	}
+	// enable or disable the interrupt based on number of defined callbacks
+	if pinISR.numDefined > 0 {
+		if nil == pinInterrupt {
+			// create the Interrupt if it is not yet defined
+			irq := interrupt.New(nxp.IRQ_GPIO6_7_8_9, pinISR.dispatchInterrupt)
+			pinInterrupt = &irq
+			pinInterrupt.Enable()
+		}
+	} else {
+		if nil != pinInterrupt {
+			// disable the interrupt if it is defined
+			pinInterrupt.Disable()
+		}
+	}
+	return nil
+}
+
+// getGPIO returns both the normal (IPG_CLK_ROOT) and high-speed (AHB_CLK_ROOT)
+// GPIO peripherals to which a given Pin is connected.
+//
+// Note that, currently, the device is configured to use high-speed GPIO for all
+// pins (GPIO6-9), so the first return value should not be used (GPIO1-4).
+// See the remarks and documentation reference in the comments preceding the
+// const Pin definitions above.
+func (p Pin) getGPIO() (norm *nxp.GPIO_Type, fast *nxp.GPIO_Type) {
+	switch p.getPort() {
+	case portA:
+		return nxp.GPIO1, nxp.GPIO6
+	case portB:
+		return nxp.GPIO2, nxp.GPIO7
+	case portC:
+		return nxp.GPIO3, nxp.GPIO8
+	case portD:
+		return nxp.GPIO4, nxp.GPIO9
+	default:
+		panic("machine: unknown port")
+	}
+}
+
+// getPad returns both the pad and mux configration registers for a given Pin.
+func (p Pin) getPad() (pad *volatile.Register32, mux *volatile.Register32) {
+	switch p.getPort() {
+	case portA:
+		switch p.getPos() {
+		case 0:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_00, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_00
+		case 1:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_01, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_01
+		case 2:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_02, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_02
+		case 3:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_03, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_03
+		case 4:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_04, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_04
+		case 5:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_05, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_05
+		case 6:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_06, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_06
+		case 7:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_07, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_07
+		case 8:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_08, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_08
+		case 9:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_09, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_09
+		case 10:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_10, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_10
+		case 11:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_11, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_11
+		case 12:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_12, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_12
+		case 13:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_13, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_13
+		case 14:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_14, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_14
+		case 15:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B0_15, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B0_15
+		case 16:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_00, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_00
+		case 17:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_01, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_01
+		case 18:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_02, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_02
+		case 19:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_03, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_03
+		case 20:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_04, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_04
+		case 21:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_05, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_05
+		case 22:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_06, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_06
+		case 23:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_07, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_07
+		case 24:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_08, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_08
+		case 25:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_09, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_09
+		case 26:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_10, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_10
+		case 27:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_11, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_11
+		case 28:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_12, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_12
+		case 29:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_13, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_13
+		case 30:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_14, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_14
+		case 31:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_AD_B1_15, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_AD_B1_15
+		}
+	case portB:
+		switch p.getPos() {
+		case 0:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_00, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_00
+		case 1:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_01, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_01
+		case 2:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_02, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_02
+		case 3:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_03, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_03
+		case 4:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_04, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_04
+		case 5:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_05, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_05
+		case 6:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_06, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_06
+		case 7:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_07, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_07
+		case 8:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_08, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_08
+		case 9:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_09, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_09
+		case 10:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_10, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_10
+		case 11:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_11, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_11
+		case 12:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_12, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_12
+		case 13:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_13, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_13
+		case 14:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_14, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_14
+		case 15:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B0_15, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B0_15
+		case 16:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_00, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_00
+		case 17:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_01, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_01
+		case 18:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_02, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_02
+		case 19:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_03, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_03
+		case 20:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_04, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_04
+		case 21:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_05, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_05
+		case 22:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_06, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_06
+		case 23:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_07, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_07
+		case 24:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_08, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_08
+		case 25:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_09, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_09
+		case 26:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_10, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_10
+		case 27:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_11, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_11
+		case 28:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_12, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_12
+		case 29:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_13, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_13
+		case 30:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_14, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_14
+		case 31:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_B1_15, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_B1_15
+		}
+	case portC:
+		switch p.getPos() {
+		case 0:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_00, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_00
+		case 1:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_01, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_01
+		case 2:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_02, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_02
+		case 3:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_03, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_03
+		case 4:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_04, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_04
+		case 5:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_05, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_05
+		case 6:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_06, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_06
+		case 7:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_07, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_07
+		case 8:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_08, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_08
+		case 9:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_09, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_09
+		case 10:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_10, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_10
+		case 11:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B1_11, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B1_11
+		case 12:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B0_00, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B0_00
+		case 13:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B0_01, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B0_01
+		case 14:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B0_02, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B0_02
+		case 15:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B0_03, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B0_03
+		case 16:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B0_04, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B0_04
+		case 17:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_SD_B0_05, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_SD_B0_05
+		case 18:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_32, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_32
+		case 19:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_33, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_33
+		case 20:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_34, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_34
+		case 21:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_35, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_35
+		case 22:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_36, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_36
+		case 23:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_37, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_37
+		case 24:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_38, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_38
+		case 25:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_39, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_39
+		case 26:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_40, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_40
+		case 27:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_41, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_41
+		case 28, 29, 30, 31:
+		}
+	case portD:
+		switch p.getPos() {
+		case 0:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_00, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_00
+		case 1:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_01, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_01
+		case 2:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_02, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_02
+		case 3:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_03, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_03
+		case 4:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_04, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_04
+		case 5:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_05, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_05
+		case 6:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_06, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_06
+		case 7:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_07, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_07
+		case 8:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_08, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_08
+		case 9:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_09, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_09
+		case 10:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_10, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_10
+		case 11:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_11, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_11
+		case 12:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_12, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_12
+		case 13:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_13, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_13
+		case 14:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_14, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_14
+		case 15:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_15, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_15
+		case 16:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_16, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_16
+		case 17:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_17, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_17
+		case 18:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_18, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_18
+		case 19:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_19, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_19
+		case 20:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_20, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_20
+		case 21:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_21, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_21
+		case 22:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_22, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_22
+		case 23:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_23, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_23
+		case 24:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_24, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_24
+		case 25:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_25, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_25
+		case 26:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_26, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_26
+		case 27:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_27, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_27
+		case 28:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_28, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_28
+		case 29:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_29, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_29
+		case 30:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_30, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_30
+		case 31:
+			return &nxp.IOMUXC.SW_PAD_CTL_PAD_GPIO_EMC_31, &nxp.IOMUXC.SW_MUX_CTL_PAD_GPIO_EMC_31
+		}
+	}
+	panic("machine: invalid pin")
+}
+
+// muxSelect is yet another level of indirection required to connect pins in an
+// alternate function state to a desired peripheral (since more than one pin can
+// provide a given alternate function).
+//
+// Once a pin is configured with a given alternate function mode, the IOMUXC
+// device must then be configured to select which alternate function pin to
+// route to the desired peripheral.
+//
+// The reference manual refers to this functionality as a "Daisy Chain". The
+// associated docs are found in the i.MX RT1060 Processor Reference Manual:
+//   "Chapter 11.3.3 Daisy chain - multi pads driving same module input pin"
+type muxSelect struct {
+	mux uint8                // AF mux selection (NOT a Pin type)
+	sel *volatile.Register32 // AF selection register
+}
+
+// connect configures the IOMUXC controller to route a given pin with alternate
+// function to a desired peripheral (see godoc comments on type muxSelect).
+func (s muxSelect) connect() {
+	s.sel.Set(uint32(s.mux))
+}
+
+// getMuxMode acts as a callback from the `(Pin).Configure(PinMode)` routine to
+// determine the alternate function setting for a given Pin and PinConfig.
+// This value is used in the IOMUXC device's SW_MUX_CTL_PAD_GPIO_* registers.
+func (p Pin) getMuxMode(config PinConfig) uint32 {
+	const forcePath = true // TODO: should be input parameter?
+	switch config.Mode {
+
+	// GPIO
+	case PinInput, PinInputPullUp, PinInputPullDown,
+		PinOutput, PinOutputOpenDrain, PinDisable:
+		mode := uint32(0x5) // GPIO is always alternate function 5
+		if forcePath {
+			mode |= 0x10 // SION bit
+		}
+		return mode
+
+	// ADC
+	case PinInputAnalog:
+		mode := uint32(0x5) // use alternate function 5 (GPIO)
+		if forcePath {
+			mode |= 0x10 // SION bit
+		}
+		return mode
+
+	// UART RX/TX
+	case PinModeUARTRX, PinModeUARTTX:
+		mode := uint32(0x2) // UART is always alternate function 2 on Teensy 4.0
+		// TODO: Teensy 4.1 has a UART (LPUART5) with alternate function 1
+		return mode
+
+	// SPI SDI
+	case PinModeSPISDI:
+		var mode uint32
+		switch p {
+		case PC15: // LPSPI1 SDI on PC15 alternate function 4
+			mode = uint32(0x4)
+		case PA2: // LPSPI3 SDI on PA2 alternate function 7
+			mode = uint32(0x7)
+		case PB1: // LPSPI4 SDI on PB1 alternate function 3
+			mode = uint32(0x3)
+		default:
+			panic("machine: invalid SPI SDI pin")
+		}
+		if forcePath {
+			mode |= 0x10 // SION bit
+		}
+		return mode
+
+	// SPI SDO
+	case PinModeSPISDO:
+		var mode uint32
+		switch p {
+		case PC14: // LPSPI1 SDO on PC14 alternate function 4
+			mode = uint32(0x4)
+		case PA30: // LPSPI3 SDO on PA30 alternate function 2
+			mode = uint32(0x2)
+		case PB2: // LPSPI4 SDO on PB2 alternate function 3
+			mode = uint32(0x3)
+		default:
+			panic("machine: invalid SPI SDO pin")
+		}
+		if forcePath {
+			mode |= 0x10 // SION bit
+		}
+		return mode
+
+	// SPI SCK
+	case PinModeSPICLK:
+		var mode uint32
+		switch p {
+		case PC12: // LPSPI1 SCK on PC12 alternate function 4
+			mode = uint32(0x4)
+		case PA31: // LPSPI3 SCK on PA31 alternate function 2
+			mode = uint32(0x2)
+		case PB3: // LPSPI4 SCK on PB3 alternate function 3
+			mode = uint32(0x3)
+		default:
+			panic("machine: invalid SPI CLK pin")
+		}
+		if forcePath {
+			mode |= 0x10 // SION bit
+		}
+		return mode
+
+	// SPI CS
+	case PinModeSPICS:
+		var mode uint32
+		switch p {
+		case PC13: // LPSPI1 CS on PC13 alternate function 4
+			mode = uint32(0x4)
+		case PA3: // LPSPI3 CS on PA3 alternate function 7
+			mode = uint32(0x7)
+		case PB0: // LPSPI4 CS on PB0 alternate function 3
+			mode = uint32(0x3)
+		default: // use alternate function 5 (GPIO) if non-CS pin selected
+			mode = uint32(0x5)
+		}
+		if forcePath {
+			mode |= 0x10 // SION bit
+		}
+		return mode
+
+	// I2C SDA
+	case PinModeI2CSDA:
+		var mode uint32
+		switch p {
+		case PA13: // LPI2C4 SDA on PA13 alternate function 0
+			mode = uint32(0)
+		case PA17: // LPI2C1 SDA on PA17 alternate function 3
+			mode = uint32(3)
+		case PA22: // LPI2C3 SDA on PA22 alternate function 1
+			mode = uint32(1)
+		default:
+			panic("machine: invalid I2C SDA pin")
+		}
+		if forcePath {
+			mode |= 0x10 // SION bit
+		}
+		return mode
+
+	// I2C SCL
+	case PinModeI2CSCL:
+		var mode uint32
+		switch p {
+		case PA12: // LPI2C4 SCL on PA12 alternate function 0
+			mode = uint32(0)
+		case PA16: // LPI2C1 SCL on PA16 alternate function 3
+			mode = uint32(3)
+		case PA23: // LPI2C3 SCL on PA23 alternate function 1
+			mode = uint32(1)
+		default:
+			panic("machine: invalid I2C SCL pin")
+		}
+		if forcePath {
+			mode |= 0x10 // SION bit
+		}
+		return mode
+
+	default:
+		panic("machine: invalid pin mode")
+	}
+}

src/machine/machine_mimxrt1062_uart.go

@@ -0,0 +1,325 @@
+// +build mimxrt1062
+
+package machine
+
+import (
+	"device/nxp"
+	"runtime/interrupt"
+	"runtime/volatile"
+)
+
+// UART peripheral abstraction layer for the MIMXRT1062
+
+type UART struct {
+	Bus       *nxp.LPUART_Type
+	Buffer    *RingBuffer
+	Interrupt interrupt.Interrupt
+
+	// these hold the input selector ("daisy chain") values that select which pins
+	// are connected to the LPUART device, and should be defined where the UART
+	// instance is declared. see the godoc comments on type muxSelect for more
+	// details.
+	muxRX, muxTX muxSelect
+
+	// these are copied from UARTConfig, during (*UART).Configure(UARTConfig), and
+	// should be considered read-only for internal reference (i.e., modifying them
+	// will have no desirable effect).
+	rx, tx Pin
+	baud   uint32
+
+	// auxiliary state data used internally
+	configured   bool
+	msbFirst     bool
+	transmitting volatile.Register32
+	txBuffer     *RingBuffer
+}
+
+func (uart *UART) isTransmitting() bool { return uart.transmitting.Get() != 0 }
+func (uart *UART) startTransmitting()   { uart.transmitting.Set(1) }
+func (uart *UART) stopTransmitting()    { uart.transmitting.Set(0) }
+func (uart *UART) resetTransmitting() {
+	uart.stopTransmitting()
+	uart.Bus.GLOBAL.SetBits(nxp.LPUART_GLOBAL_RST)
+	uart.Bus.GLOBAL.ClearBits(nxp.LPUART_GLOBAL_RST)
+}
+
+// Configure initializes a UART with the given UARTConfig and other default
+// settings.
+func (uart *UART) Configure(config UARTConfig) {
+
+	const defaultUartFreq = 115200
+
+	// use default baud rate if not specified
+	if config.BaudRate == 0 {
+		config.BaudRate = defaultUartFreq
+	}
+	uart.baud = config.BaudRate
+
+	// use default UART pins if not specified
+	if config.RX == 0 && config.TX == 0 {
+		config.RX = UART_RX_PIN
+		config.TX = UART_TX_PIN
+	}
+	uart.rx = config.RX
+	uart.tx = config.TX
+
+	// configure the mux and pad control registers
+	uart.rx.Configure(PinConfig{Mode: PinModeUARTRX})
+	uart.tx.Configure(PinConfig{Mode: PinModeUARTTX})
+
+	// configure the mux input selector
+	uart.muxRX.connect()
+	uart.muxTX.connect()
+
+	// reset all internal logic and registers
+	uart.resetTransmitting()
+
+	// determine the baud rate and over-sample divisors
+	sbr, osr := uart.getBaudRateDivisor(uart.baud)
+
+	// for now we assume some configuration. in particular:
+	//  Data bits         -> 8-bit
+	//  Parity bit        -> None (parity bit generation disabled)
+	//  Stop bits         -> 1 stop bit
+	//  MSB first         -> false
+	//  RX idle type      -> idle count starts after start bit
+	//  RX idle config    -> 1 idle character
+	//  RX RTS enabled    -> false
+	//  TX CTS enabled    -> false
+
+	// set the baud rate, over-sample configuration, stop bits
+	baudBits := (((osr - 1) << nxp.LPUART_BAUD_OSR_Pos) & nxp.LPUART_BAUD_OSR_Msk) |
+		((sbr << nxp.LPUART_BAUD_SBR_Pos) & nxp.LPUART_BAUD_SBR_Msk) |
+		((nxp.LPUART_BAUD_SBNS_SBNS_0 << nxp.LPUART_BAUD_SBNS_Pos) & nxp.LPUART_BAUD_SBNS_Msk)
+	if osr <= 8 {
+		// if OSR less than or equal to 8, we must enable sampling on both edges
+		baudBits |= nxp.LPUART_BAUD_BOTHEDGE
+	}
+	uart.Bus.BAUD.Set(baudBits)
+
+	uart.Bus.PINCFG.Set(0) // disable triggers
+
+	// use 8 data bits, disable parity, use 1 idle char, and idle count starts
+	// after start bit
+	ctrlBits := uint32(((nxp.LPUART_CTRL_M_M_0 << nxp.LPUART_CTRL_M_Pos) & nxp.LPUART_CTRL_M_Msk) |
+		((nxp.LPUART_CTRL_PE_PE_0 << nxp.LPUART_CTRL_PE_Pos) & nxp.LPUART_CTRL_PE_Msk) |
+		((nxp.LPUART_CTRL_ILT_ILT_0 << nxp.LPUART_CTRL_ILT_Pos) & nxp.LPUART_CTRL_ILT_Msk) |
+		((nxp.LPUART_CTRL_IDLECFG_IDLECFG_0 << nxp.LPUART_CTRL_IDLECFG_Pos) & nxp.LPUART_CTRL_IDLECFG_Msk))
+	uart.Bus.CTRL.Set(ctrlBits)
+
+	rxSize, txSize := uart.getFIFOSize()
+
+	rxWater := rxSize >> 1
+	if rxWater > uint32(nxp.LPUART_FIFO_RXFIFOSIZE_Msk>>nxp.LPUART_FIFO_RXFIFOSIZE_Pos) {
+		rxWater = uint32(nxp.LPUART_FIFO_RXFIFOSIZE_Msk >> nxp.LPUART_FIFO_RXFIFOSIZE_Pos)
+	}
+
+	txWater := txSize >> 1
+	if txWater > uint32(nxp.LPUART_FIFO_TXFIFOSIZE_Msk>>nxp.LPUART_FIFO_TXFIFOSIZE_Pos) {
+		txWater = uint32(nxp.LPUART_FIFO_TXFIFOSIZE_Msk >> nxp.LPUART_FIFO_TXFIFOSIZE_Pos)
+	}
+
+	uart.Bus.WATER.Set(
+		((rxWater << nxp.LPUART_WATER_RXWATER_Pos) & nxp.LPUART_WATER_RXWATER_Msk) |
+			((txWater << nxp.LPUART_WATER_TXWATER_Pos) & nxp.LPUART_WATER_TXWATER_Msk))
+
+	// enable TX/RX FIFOs
+	uart.Bus.FIFO.SetBits(nxp.LPUART_FIFO_RXFE | nxp.LPUART_FIFO_TXFE)
+
+	// flush TX/RX FIFOs
+	uart.Bus.FIFO.SetBits(nxp.LPUART_FIFO_RXFLUSH | nxp.LPUART_FIFO_TXFLUSH)
+
+	uart.Bus.MODIR.SetBits( // set the CTS configuration/TX CTS source
+		((nxp.LPUART_MODIR_TXCTSC_TXCTSC_0 << nxp.LPUART_MODIR_TXCTSC_Pos) & nxp.LPUART_MODIR_TXCTSC_Msk) |
+			((nxp.LPUART_MODIR_TXCTSSRC_TXCTSSRC_0 << nxp.LPUART_MODIR_TXCTSSRC_Pos) & nxp.LPUART_MODIR_TXCTSSRC_Msk))
+
+	// clear all status flags
+	stat := uint32(nxp.LPUART_STAT_RXEDGIF_Msk | nxp.LPUART_STAT_IDLE_Msk | nxp.LPUART_STAT_OR_Msk |
+		nxp.LPUART_STAT_NF_Msk | nxp.LPUART_STAT_FE_Msk | nxp.LPUART_STAT_PF_Msk |
+		nxp.LPUART_STAT_LBKDIF_Msk | nxp.LPUART_STAT_MA1F_Msk | nxp.LPUART_STAT_MA2F_Msk)
+
+	// set data bits order
+	if uart.msbFirst {
+		stat |= nxp.LPUART_STAT_MSBF
+	} else {
+		stat &^= nxp.LPUART_STAT_MSBF
+	}
+
+	uart.Bus.STAT.SetBits(stat)
+
+	// enable RX/TX functions
+	uart.Bus.CTRL.SetBits(nxp.LPUART_CTRL_TE | nxp.LPUART_CTRL_RE)
+
+	// enable RX IRQ
+	uart.Interrupt.SetPriority(0xc0)
+	uart.Interrupt.Enable()
+
+	uart.configured = true
+}
+
+// Disable disables the UART interface.
+//
+// If any buffered data has not yet been transmitted, Disable waits until
+// transmission completes before disabling the interface. The receiver UART's
+// interrupt is also disabled, and the RX/TX pins are reconfigured for GPIO
+// input (pull-up).
+func (uart *UART) Disable() {
+
+	// first ensure the device is enabled
+	if uart.configured {
+
+		// wait for any buffered data to send
+		uart.Sync()
+
+		// stop trapping RX interrupts
+		uart.Interrupt.Disable()
+
+		// reset all internal registers
+		uart.resetTransmitting()
+
+		// disable RX/TX functions
+		uart.Bus.CTRL.ClearBits(nxp.LPUART_CTRL_TE | nxp.LPUART_CTRL_RE)
+
+		// put pins back into GPIO mode
+		uart.rx.Configure(PinConfig{Mode: PinInputPullUp})
+		uart.tx.Configure(PinConfig{Mode: PinInputPullUp})
+	}
+	uart.configured = false
+}
+
+// Sync blocks the calling goroutine until all data in the output buffer has
+// been transmitted.
+func (uart *UART) Sync() error {
+	for uart.isTransmitting() {
+	}
+	return nil
+}
+
+// WriteByte writes a single byte of data to the UART interface.
+func (uart *UART) WriteByte(c byte) error {
+	if nil == uart.txBuffer {
+		uart.txBuffer = NewRingBuffer()
+	}
+	uart.startTransmitting()
+	for !uart.txBuffer.Put(c) {
+	}
+	uart.Bus.CTRL.SetBits(nxp.LPUART_CTRL_TIE)
+	return nil
+}
+
+// getBaudRateDivisor finds the greatest over-sampling factor (4..32) and
+// corresponding baud rate divisor (1..8191) that best partition a given baud
+// rate into equal intervals.
+//
+// This is an integral (i.e. non-floating point) port of the logic at the
+// beginning of:
+//       void HardwareSerial::begin(uint32_t baud, uint16_t format)
+//         (from Teensyduino: `cores/teensy4/HardwareSerial.cpp`)
+//
+// We don't want to risk using floating point here in the machine package in
+// case it gets called before the FPU or interrupts are ready (e.g., init()).
+func (uart *UART) getBaudRateDivisor(baudRate uint32) (sbr uint32, osr uint32) {
+	const clock = 24000000 // UART is muxed to 24 MHz OSC
+	err := uint32(0xFFFFFFFF)
+	sbr, osr = 0, 0
+	for o := uint32(4); o <= 32; o++ {
+		s := ((clock*10)/(baudRate*o) + 5) / 10
+		if s == 0 {
+			s = 1
+		}
+		b := clock / (s * o)
+		var e uint32
+		if b > baudRate {
+			e = b - baudRate
+		} else {
+			e = baudRate - b
+		}
+		if e <= err {
+			err = e
+			osr = o
+			sbr = s
+		}
+	}
+	return sbr, osr
+}
+
+func (uart *UART) getFIFOSize() (rx, tx uint32) {
+	fifo := uart.Bus.FIFO.Get()
+	rx = uint32(1) << ((fifo & nxp.LPUART_FIFO_RXFIFOSIZE_Msk) >> nxp.LPUART_FIFO_RXFIFOSIZE_Pos)
+	if rx > 1 {
+		rx <<= 1
+	}
+	tx = uint32(1) << ((fifo & nxp.LPUART_FIFO_TXFIFOSIZE_Msk) >> nxp.LPUART_FIFO_TXFIFOSIZE_Pos)
+	if tx > 1 {
+		tx <<= 1
+	}
+	return rx, tx
+}
+
+func (uart *UART) getStatus() uint32 {
+	return uart.Bus.STAT.Get() |
+		((uart.Bus.FIFO.Get() & uint32(nxp.LPUART_FIFO_TXEMPT_Msk|nxp.LPUART_FIFO_RXEMPT_Msk|
+			nxp.LPUART_FIFO_TXOF_Msk|nxp.LPUART_FIFO_RXUF_Msk)) >> 16)
+}
+
+func (uart *UART) getEnabledInterrupts() uint32 {
+	return ((uart.Bus.BAUD.Get() & uint32(nxp.LPUART_BAUD_LBKDIE_Msk|nxp.LPUART_BAUD_RXEDGIE_Msk)) >> 8) |
+		((uart.Bus.FIFO.Get() & uint32(nxp.LPUART_FIFO_TXOFE_Msk|nxp.LPUART_FIFO_RXUFE_Msk)) >> 8) |
+		(uart.Bus.CTRL.Get() & uint32(0xFF0C000))
+}
+
+func (uart *UART) disableInterrupts(mask uint32) {
+	uart.Bus.BAUD.ClearBits((mask << 8) & uint32(nxp.LPUART_BAUD_LBKDIE_Msk|nxp.LPUART_BAUD_RXEDGIE_Msk))
+	uart.Bus.FIFO.Set((uart.Bus.FIFO.Get() & ^uint32(nxp.LPUART_FIFO_TXOF_Msk|nxp.LPUART_FIFO_RXUF_Msk)) &
+		^uint32((mask<<8)&(nxp.LPUART_FIFO_TXOFE_Msk|nxp.LPUART_FIFO_RXUFE_Msk)))
+	mask &= uint32(0xFFFFFF00)
+	uart.Bus.CTRL.ClearBits(mask)
+}
+
+func (uart *UART) handleInterrupt(interrupt.Interrupt) {
+
+	stat := uart.getStatus()
+	inte := uart.getEnabledInterrupts()
+
+	_, txSize := uart.getFIFOSize()
+
+	// check for and clear overrun, otherwise RX will not work
+	if (stat & uint32(nxp.LPUART_STAT_OR)) != 0 {
+		uart.Bus.STAT.Set((uart.Bus.STAT.Get() & uint32(0x3FE00000)) | nxp.LPUART_STAT_OR)
+	}
+
+	// idle or receive data register is full
+	if (stat & uint32(nxp.LPUART_STAT_RDRF|nxp.LPUART_STAT_IDLE)) != 0 {
+		count := (uart.Bus.WATER.Get() & uint32(nxp.LPUART_WATER_RXCOUNT_Msk)) >> nxp.LPUART_WATER_RXCOUNT_Pos
+		for ; count > 0; count-- {
+			// read up to 8 bits of data at a time
+			// TODO: 7, 9, and 10-bit support?
+			uart.Buffer.Put(uint8(uart.Bus.DATA.Get() & uint32(0xFF)))
+		}
+		// if it was an IDLE status, clear the flag
+		if (stat & uint32(nxp.LPUART_STAT_IDLE)) != 0 {
+			uart.Bus.STAT.SetBits(nxp.LPUART_STAT_IDLE)
+		}
+		// disable idle line interrupts
+		uart.disableInterrupts(nxp.LPUART_CTRL_RIE | nxp.LPUART_CTRL_ORIE)
+	}
+
+	// check if we have data to write
+	if ((inte & nxp.LPUART_CTRL_TIE) != 0) && ((stat & nxp.LPUART_STAT_TDRE) != 0) {
+		for ((uart.Bus.WATER.Get() & uint32(nxp.LPUART_WATER_TXCOUNT_Msk)) >> nxp.LPUART_WATER_TXCOUNT_Pos) < txSize {
+			if b, ok := uart.txBuffer.Get(); ok {
+				uart.Bus.DATA.Set(uint32(b))
+			} else {
+				break
+			}
+		}
+		if uart.Bus.STAT.HasBits(nxp.LPUART_STAT_TDRE) {
+			uart.Bus.CTRL.Set((uart.Bus.CTRL.Get() & ^uint32(nxp.LPUART_CTRL_TIE)) | nxp.LPUART_CTRL_TCIE)
+		}
+	}
+
+	if ((inte & nxp.LPUART_CTRL_TCIE) != 0) && ((stat & nxp.LPUART_STAT_TC) != 0) {
+		uart.stopTransmitting()
+		uart.Bus.CTRL.ClearBits(nxp.LPUART_CTRL_TCIE)
+	}
+}

src/machine/machine_nrf.go

@@ -72,7 +72,8 @@ func (p Pin) Get() bool {
 }
 
 // SetInterrupt sets an interrupt to be executed when a particular pin changes
-// state.
+// state. The pin should already be configured as an input, including a pull up
+// or down if no external pull is provided.
 //
 // This call will replace a previously set callback on this pin. You can pass a
 // nil func to unset the pin change interrupt. If you do so, the change
@@ -258,12 +259,15 @@ func (i2c I2C) Configure(config I2CConfig) {
 // Tx does a single I2C transaction at the specified address.
 // It clocks out the given address, writes the bytes in w, reads back len(r)
 // bytes and stores them in r, and generates a stop condition on the bus.
-func (i2c I2C) Tx(addr uint16, w, r []byte) error {
+func (i2c I2C) Tx(addr uint16, w, r []byte) (err error) {
 	i2c.Bus.ADDRESS.Set(uint32(addr))
+
 	if len(w) != 0 {
 		i2c.Bus.TASKS_STARTTX.Set(1) // start transmission for writing
 		for _, b := range w {
-			i2c.writeByte(b)
+			if err = i2c.writeByte(b); err != nil {
+				goto cleanUp
+			}
 		}
 	}
 	if len(r) != 0 {
@@ -276,12 +280,18 @@ func (i2c I2C) Tx(addr uint16, w, r []byte) error {
 				i2c.Bus.SHORTS.Set(nrf.TWI_SHORTS_BB_STOP)
 			}
 			i2c.Bus.TASKS_RESUME.Set(1) // re-start transmission for reading
-			r[i] = i2c.readByte()
+			if r[i], err = i2c.readByte(); err != nil {
+				// goto/break are practically equivalent here,
+				// but goto makes this more easily understandable for maintenance.
+				goto cleanUp
+			}
 		}
 	}
+
+cleanUp:
 	i2c.signalStop()
 	i2c.Bus.SHORTS.Set(nrf.TWI_SHORTS_BB_SUSPEND_Disabled)
-	return nil
+	return
 }
 
 // signalStop sends a stop signal when writing or tells the I2C peripheral that
@@ -295,19 +305,28 @@ func (i2c I2C) signalStop() {
 }
 
 // writeByte writes a single byte to the I2C bus.
-func (i2c I2C) writeByte(data byte) {
+func (i2c I2C) writeByte(data byte) error {
 	i2c.Bus.TXD.Set(uint32(data))
 	for i2c.Bus.EVENTS_TXDSENT.Get() == 0 {
+		if e := i2c.Bus.EVENTS_ERROR.Get(); e != 0 {
+			i2c.Bus.EVENTS_ERROR.Set(0)
+			return errI2CBusError
+		}
 	}
 	i2c.Bus.EVENTS_TXDSENT.Set(0)
+	return nil
 }
 
 // readByte reads a single byte from the I2C bus.
-func (i2c I2C) readByte() byte {
+func (i2c I2C) readByte() (byte, error) {
 	for i2c.Bus.EVENTS_RXDREADY.Get() == 0 {
+		if e := i2c.Bus.EVENTS_ERROR.Get(); e != 0 {
+			i2c.Bus.EVENTS_ERROR.Set(0)
+			return 0, errI2CBusError
+		}
 	}
 	i2c.Bus.EVENTS_RXDREADY.Set(0)
-	return byte(i2c.Bus.RXD.Get())
+	return byte(i2c.Bus.RXD.Get()), nil
 }
 
 // SPI on the NRF.
@@ -339,23 +358,25 @@ func (spi SPI) Configure(config SPIConfig) {
 	// set frequency
 	var freq uint32
 
-	switch config.Frequency {
-	case 125000:
-		freq = nrf.SPI_FREQUENCY_FREQUENCY_K125
-	case 250000:
-		freq = nrf.SPI_FREQUENCY_FREQUENCY_K250
-	case 500000:
-		freq = nrf.SPI_FREQUENCY_FREQUENCY_K500
-	case 1000000:
-		freq = nrf.SPI_FREQUENCY_FREQUENCY_M1
-	case 2000000:
-		freq = nrf.SPI_FREQUENCY_FREQUENCY_M2
-	case 4000000:
-		freq = nrf.SPI_FREQUENCY_FREQUENCY_M4
-	case 8000000:
+	if config.Frequency == 0 {
+		config.Frequency = 4000000 // 4MHz
+	}
+
+	switch {
+	case config.Frequency >= 8000000:
 		freq = nrf.SPI_FREQUENCY_FREQUENCY_M8
-	default:
+	case config.Frequency >= 4000000:
+		freq = nrf.SPI_FREQUENCY_FREQUENCY_M4
+	case config.Frequency >= 2000000:
+		freq = nrf.SPI_FREQUENCY_FREQUENCY_M2
+	case config.Frequency >= 1000000:
+		freq = nrf.SPI_FREQUENCY_FREQUENCY_M1
+	case config.Frequency >= 500000:
 		freq = nrf.SPI_FREQUENCY_FREQUENCY_K500
+	case config.Frequency >= 250000:
+		freq = nrf.SPI_FREQUENCY_FREQUENCY_K250
+	default: // below 250kHz, default to the lowest speed available
+		freq = nrf.SPI_FREQUENCY_FREQUENCY_K125
 	}
 	spi.Bus.FREQUENCY.Set(freq)
 

src/machine/machine_stm32.go

@@ -4,6 +4,19 @@ package machine
 
 // Peripheral abstraction layer for the stm32.
 
+const (
+	portA Pin = iota * 16
+	portB
+	portC
+	portD
+	portE
+	portF
+	portG
+	portH
+	portI
+	portJ
+)
+
 type PinMode uint8
 
 // Peripheral operations sequence:

src/machine/machine_stm32_i2c.go

@@ -0,0 +1,481 @@
+// +build stm32,!stm32f103xx,!stm32f407
+
+package machine
+
+// Peripheral abstraction layer for I2C on the stm32 family
+
+import (
+	"device/stm32"
+	"unsafe"
+)
+
+const (
+	flagOVR     = 0x00010800
+	flagAF      = 0x00010400
+	flagARLO    = 0x00010200
+	flagBERR    = 0x00010100
+	flagTXE     = 0x00010080
+	flagRXNE    = 0x00010040
+	flagSTOPF   = 0x00010010
+	flagADD10   = 0x00010008
+	flagBTF     = 0x00010004
+	flagADDR    = 0x00010002
+	flagSB      = 0x00010001
+	flagDUALF   = 0x00100080
+	flagGENCALL = 0x00100010
+	flagTRA     = 0x00100004
+	flagBUSY    = 0x00100002
+	flagMSL     = 0x00100001
+)
+
+func (i2c I2C) hasFlag(flag uint32) bool {
+	const mask = 0x0000FFFF
+	if uint8(flag>>16) == 1 {
+		return i2c.Bus.SR1.HasBits(flag & mask)
+	} else {
+		return i2c.Bus.SR2.HasBits(flag & mask)
+	}
+}
+
+func (i2c I2C) clearFlag(flag uint32) {
+	const mask = 0x0000FFFF
+	i2c.Bus.SR1.Set(^(flag & mask))
+}
+
+// clearFlagADDR reads both status registers to clear any pending ADDR flags.
+func (i2c I2C) clearFlagADDR() {
+	i2c.Bus.SR1.Get()
+	i2c.Bus.SR2.Get()
+}
+
+func (i2c I2C) waitForFlag(flag uint32, set bool) bool {
+	const tryMax = 10000
+	hasFlag := false
+	for i := 0; !hasFlag && i < tryMax; i++ {
+		hasFlag = i2c.hasFlag(flag) == set
+	}
+	return hasFlag
+}
+
+func (i2c I2C) waitForFlagOrError(flag uint32, set bool) bool {
+	const tryMax = 10000
+	hasFlag := false
+	for i := 0; !hasFlag && i < tryMax; i++ {
+		if hasFlag = i2c.hasFlag(flag) == set; !hasFlag {
+			// check for ACK failure
+			if i2c.hasFlag(flagAF) {
+				// generate stop condition
+				i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
+				// clear pending flags
+				i2c.clearFlag(flagAF)
+				return false
+			} else if i2c.hasFlag(flagSTOPF) {
+				// clear stop flag
+				i2c.clearFlag(flagSTOPF)
+				return false
+			}
+		}
+	}
+	return hasFlag
+}
+
+type transferOption uint32
+
+const (
+	frameFirst        = 0x00000001
+	frameFirstAndNext = 0x00000002
+	frameNext         = 0x00000004
+	frameFirstAndLast = 0x00000008
+	frameLastNoStop   = 0x00000010
+	frameLast         = 0x00000020
+	frameNoOption     = 0xFFFF0000
+)
+
+// addressable represents a type that can provide fully-formatted I2C peripheral
+// addresses for both read operations and write operations.
+type addressable interface {
+	toRead() uint32
+	toWrite() uint32
+	bitSize() uint8
+}
+
+// address7Bit and address10Bit stores the unshifted original I2C peripheral address
+// in an unsigned integral data type and implements the addressable interface
+// to reformat addresses as required for read/write operations.
+//   TODO:
+//    add 10-bit address support
+type (
+	address7Bit uint8
+	//address10Bit uint16
+)
+
+func (sa address7Bit) toRead() uint32 {
+	return uint32(((uint8(sa) << 1) | uint8(stm32.I2C_OAR1_ADD0)) & 0xFF)
+}
+func (sa address7Bit) toWrite() uint32 {
+	return uint32(((uint8(sa) << 1) & ^(uint8(stm32.I2C_OAR1_ADD0))) & 0xFF)
+}
+func (sa address7Bit) bitSize() uint8 { return 7 } // 7-bit addresses
+
+//func (sa address10Bit) toRead() uint32  {}
+//func (sa address10Bit) toWrite() uint32 {}
+//func (sa address10Bit) bitSize() uint8  { return 10 } // 10-bit addresses
+
+func readAddress7Bit(addr uint8) uint32  { return address7Bit(addr).toRead() }
+func writeAddress7Bit(addr uint8) uint32 { return address7Bit(addr).toWrite() }
+
+//func readAddress10Bit(addr uint16) uint32  { return address10Bit(addr).toRead() }
+//func writeAddress10Bit(addr uint16) uint32 { return address10Bit(addr).toWrite() }
+
+// I2C fast mode (Fm) duty cycle
+const (
+	DutyCycle2    = 0
+	DutyCycle16x9 = 1
+)
+
+// I2CConfig is used to store config info for I2C.
+type I2CConfig struct {
+	Frequency uint32
+	SCL       Pin
+	SDA       Pin
+	DutyCycle uint8
+}
+
+// Configure is intended to setup the STM32 I2C interface.
+func (i2c I2C) Configure(config I2CConfig) {
+
+	// The following is the required sequence in controller mode.
+	// 1. Program the peripheral input clock in I2C_CR2 Register in order to
+	//    generate correct timings
+	// 2. Configure the clock control registers
+	// 3. Configure the rise time register
+	// 4. Program the I2C_CR1 register to enable the peripheral
+	// 5. Set the START bit in the I2C_CR1 register to generate a Start condition
+
+	// disable I2C interface before any configuration changes
+	i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_PE)
+
+	// reset I2C bus
+	i2c.Bus.CR1.SetBits(stm32.I2C_CR1_SWRST)
+	i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_SWRST)
+
+	// enable clock for I2C
+	enableAltFuncClock(unsafe.Pointer(i2c.Bus))
+
+	// init pins
+	if config.SCL == 0 && config.SDA == 0 {
+		config.SCL = I2C0_SCL_PIN
+		config.SDA = I2C0_SDA_PIN
+	}
+	i2c.configurePins(config)
+
+	// default to 100 kHz (Sm, standard mode) if no frequency is set
+	if config.Frequency == 0 {
+		config.Frequency = TWI_FREQ_100KHZ
+	}
+
+	// configure I2C input clock
+	i2c.Bus.CR2.SetBits(i2c.getFreqRange(config))
+
+	// configure rise time
+	i2c.Bus.TRISE.Set(i2c.getRiseTime(config))
+
+	// configure clock control
+	i2c.Bus.CCR.Set(i2c.getSpeed(config))
+
+	// disable GeneralCall and NoStretch modes
+	i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_ENGC | stm32.I2C_CR1_NOSTRETCH)
+
+	// enable I2C interface
+	i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_PE)
+}
+
+func (i2c I2C) Tx(addr uint16, w, r []byte) error {
+	a := address7Bit(addr)
+	if err := i2c.controllerTransmit(a, w); nil != err {
+		return err
+	}
+	if err := i2c.controllerReceive(a, r); nil != err {
+		return err
+	}
+	return nil
+}
+
+func (i2c I2C) controllerTransmit(addr addressable, w []byte) error {
+
+	if !i2c.waitForFlag(flagBUSY, false) {
+		return errI2CBusReadyTimeout
+	}
+
+	// ensure peripheral is enabled
+	if !i2c.Bus.CR1.HasBits(stm32.I2C_CR1_PE) {
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_PE)
+	}
+
+	// disable POS
+	i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_POS)
+
+	pos := 0
+	rem := len(w)
+
+	// send peripheral address
+	if err := i2c.controllerRequestWrite(addr, frameNoOption); nil != err {
+		return err
+	}
+
+	// clear ADDR flag
+	i2c.clearFlagADDR()
+
+	for rem > 0 {
+		// wait for TXE flag set
+		if !i2c.waitForFlagOrError(flagTXE, true) {
+			return errI2CAckExpected
+		}
+
+		// write data to DR
+		i2c.Bus.DR.Set(uint32(w[pos]))
+		// update counters
+		pos++
+		rem--
+
+		if i2c.hasFlag(flagBTF) && rem != 0 {
+			// write data to DR
+			i2c.Bus.DR.Set(uint32(w[pos]))
+			// update counters
+			pos++
+			rem--
+		}
+
+		// wait for transfer finished flag BTF set
+		if !i2c.waitForFlagOrError(flagBTF, true) {
+			return errI2CWriteTimeout
+		}
+	}
+
+	// generate stop condition
+	i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
+
+	return nil
+}
+
+func (i2c I2C) controllerRequestWrite(addr addressable, option transferOption) error {
+
+	if frameFirstAndLast == option || frameFirst == option || frameNoOption == option {
+		// generate start condition
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_START)
+	} else if false /* (hi2c->PreviousState == I2C_STATE_MASTER_BUSY_RX) */ {
+		// generate restart condition
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_START)
+	}
+
+	// ensure start bit is set
+	if !i2c.waitForFlag(flagSB, true) {
+		return errI2CSignalStartTimeout
+	}
+
+	// send peripheral address
+	switch addr.bitSize() {
+	case 7: // 7-bit peripheral address
+		i2c.Bus.DR.Set(addr.toWrite())
+
+	case 10: // 10-bit peripheral address
+		// TODO
+	}
+
+	// wait for address ACK from peripheral
+	if !i2c.waitForFlagOrError(flagADDR, true) {
+		return errI2CSignalStartTimeout
+	}
+
+	return nil
+}
+
+func (i2c I2C) controllerReceive(addr addressable, r []byte) error {
+
+	if !i2c.waitForFlag(flagBUSY, false) {
+		return errI2CBusReadyTimeout
+	}
+
+	// ensure peripheral is enabled
+	if !i2c.Bus.CR1.HasBits(stm32.I2C_CR1_PE) {
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_PE)
+	}
+
+	// disable POS
+	i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_POS)
+
+	pos := 0
+	rem := len(r)
+
+	// send peripheral address
+	if err := i2c.controllerRequestRead(addr, frameNoOption); nil != err {
+		return err
+	}
+
+	switch rem {
+	case 0:
+		// clear ADDR flag
+		i2c.clearFlagADDR()
+		// generate stop condition
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
+
+	case 1:
+		// disable ACK
+		i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_ACK)
+		// clear ADDR flag
+		i2c.clearFlagADDR()
+		// generate stop condition
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
+
+	case 2:
+		// disable ACK
+		i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_ACK)
+		// enable POS
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_POS)
+		// clear ADDR flag
+		i2c.clearFlagADDR()
+
+	default:
+		// enable ACK
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_ACK)
+		// clear ADDR flag
+		i2c.clearFlagADDR()
+	}
+
+	for rem > 0 {
+		switch rem {
+		case 1:
+			// wait until RXNE flag is set
+			if !i2c.waitForFlagOrError(flagRXNE, true) {
+				return errI2CReadTimeout
+			}
+
+			// read data from DR
+			r[pos] = byte(i2c.Bus.DR.Get())
+
+			// update counters
+			pos++
+			rem--
+
+		case 2:
+			// wait until transfer finished flag BTF is set
+			if !i2c.waitForFlag(flagBTF, true) {
+				return errI2CReadTimeout
+			}
+
+			// generate stop condition
+			i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
+
+			// read data from DR
+			r[pos] = byte(i2c.Bus.DR.Get())
+
+			// update counters
+			pos++
+			rem--
+
+			// read data from DR
+			r[pos] = byte(i2c.Bus.DR.Get())
+
+			// update counters
+			pos++
+			rem--
+
+		case 3:
+			// wait until transfer finished flag BTF is set
+			if !i2c.waitForFlag(flagBTF, true) {
+				return errI2CReadTimeout
+			}
+
+			// disable ACK
+			i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_ACK)
+
+			// read data from DR
+			r[pos] = byte(i2c.Bus.DR.Get())
+
+			// update counters
+			pos++
+			rem--
+
+			// wait until transfer finished flag BTF is set
+			if !i2c.waitForFlag(flagBTF, true) {
+				return errI2CReadTimeout
+			}
+
+			// generate stop condition
+			i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
+
+			// read data from DR
+			r[pos] = byte(i2c.Bus.DR.Get())
+
+			// update counters
+			pos++
+			rem--
+
+			// read data from DR
+			r[pos] = byte(i2c.Bus.DR.Get())
+
+			// update counters
+			pos++
+			rem--
+
+		default:
+			// wait until RXNE flag is set
+			if !i2c.waitForFlagOrError(flagRXNE, true) {
+				return errI2CReadTimeout
+			}
+
+			// read data from DR
+			r[pos] = byte(i2c.Bus.DR.Get())
+
+			// update counters
+			pos++
+			rem--
+
+			if i2c.hasFlag(flagBTF) {
+				// read data from DR
+				r[pos] = byte(i2c.Bus.DR.Get())
+
+				// update counters
+				pos++
+				rem--
+			}
+		}
+	}
+
+	return nil
+}
+
+func (i2c I2C) controllerRequestRead(addr addressable, option transferOption) error {
+
+	// enable ACK
+	i2c.Bus.CR1.SetBits(stm32.I2C_CR1_ACK)
+
+	if frameFirstAndLast == option || frameFirst == option || frameNoOption == option {
+		// generate start condition
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_START)
+	} else if false /* (hi2c->PreviousState == I2C_STATE_MASTER_BUSY_TX) */ {
+		// generate restart condition
+		i2c.Bus.CR1.SetBits(stm32.I2C_CR1_START)
+	}
+
+	// ensure start bit is set
+	if !i2c.waitForFlag(flagSB, true) {
+		return errI2CSignalStartTimeout
+	}
+
+	// send peripheral address
+	switch addr.bitSize() {
+	case 7: // 7-bit peripheral address
+		i2c.Bus.DR.Set(addr.toRead())
+
+	case 10: // 10-bit peripheral address
+		// TODO
+	}
+
+	// wait for address ACK from peripheral
+	if !i2c.waitForFlagOrError(flagADDR, true) {
+		return errI2CSignalStartTimeout
+	}
+
+	return nil
+}

src/machine/machine_stm32_spi.go

@@ -20,15 +20,42 @@ type SPIConfig struct {
 }
 
 // Configure is intended to setup the STM32 SPI1 interface.
-// Features still TODO:
-// - support SPI2 and SPI3
-// - allow setting data size to 16 bits?
-// - allow setting direction in HW for additional optimization?
-// - hardware SS pin?
 func (spi SPI) Configure(config SPIConfig) {
+
+	// -- CONFIGURING THE SPI IN MASTER MODE --
+	//
+	// 1. Select the BR[2:0] bits to define the serial clock baud rate (see
+	// 	  SPI_CR1 register).
+	// 2. Select the CPOL and CPHA bits to define one of the four relationships
+	//    between the data transfer and the serial clock (see Figure 248). This
+	//    step is not required when the TI mode is selected.
+	// 3. Set the DFF bit to define 8- or 16-bit data frame format
+	// 4. Configure the LSBFIRST bit in the SPI_CR1 register to define the frame
+	//    format. This step is not required when the TI mode is selected.
+	// 5. If the NSS pin is required in input mode, in hardware mode, connect the
+	//    NSS pin to a high-level signal during the complete byte transmit
+	//    sequence. In NSS software mode, set the SSM and SSI bits in the SPI_CR1
+	//    register. If the NSS pin is required in output mode, the SSOE bit only
+	//    should be set. This step is not required when the TI mode is selected.
+	// 6. Set the FRF bit in SPI_CR2 to select the TI protocol for serial
+	//    communications.
+	// 7. The MSTR and SPE bits must be set (they remain set only if the NSS pin
+	//    is connected to a high-level signal).
+
+	// disable SPI interface before any configuration changes
+	spi.Bus.CR1.ClearBits(stm32.SPI_CR1_SPE)
+
 	// enable clock for SPI
 	enableAltFuncClock(unsafe.Pointer(spi.Bus))
 
+	// init pins
+	if config.SCK == 0 && config.SDO == 0 && config.SDI == 0 {
+		config.SCK = SPI0_SCK_PIN
+		config.SDO = SPI0_SDO_PIN
+		config.SDI = SPI0_SDI_PIN
+	}
+	spi.configurePins(config)
+
 	// Get SPI baud rate based on the bus speed it's attached to
 	var conf uint32 = spi.getBaudRate(config)
 
@@ -39,61 +66,72 @@ func (spi SPI) Configure(config SPIConfig) {
 
 	// set polarity and phase on the SPI interface
 	switch config.Mode {
-	case Mode0:
-		conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
-		conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
 	case Mode1:
-		conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
-		conf |= (1 << stm32.SPI_CR1_CPHA_Pos)
+		conf |= stm32.SPI_CR1_CPHA
 	case Mode2:
-		conf |= (1 << stm32.SPI_CR1_CPOL_Pos)
-		conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
+		conf |= stm32.SPI_CR1_CPOL
 	case Mode3:
-		conf |= (1 << stm32.SPI_CR1_CPOL_Pos)
-		conf |= (1 << stm32.SPI_CR1_CPHA_Pos)
-	default: // to mode 0
-		conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
-		conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
+		conf |= stm32.SPI_CR1_CPOL
+		conf |= stm32.SPI_CR1_CPHA
 	}
 
-	// set to SPI controller
-	conf |= stm32.SPI_CR1_MSTR
+	// configure as SPI master
+	conf |= stm32.SPI_CR1_MSTR | stm32.SPI_CR1_SSI
 
-	// disable MCU acting as SPI peripheral
-	conf |= stm32.SPI_CR1_SSM | stm32.SPI_CR1_SSI
+	// enable the SPI interface
+	conf |= stm32.SPI_CR1_SPE
+
+	// use software CS (GPIO) by default
+	conf |= stm32.SPI_CR1_SSM
 
 	// now set the configuration
 	spi.Bus.CR1.Set(conf)
-
-	// init pins
-	if config.SCK == 0 && config.SDO == 0 && config.SDI == 0 {
-		config.SCK = SPI0_SCK_PIN
-		config.SDO = SPI0_SDO_PIN
-		config.SDI = SPI0_SDI_PIN
-	}
-	spi.configurePins(config)
-
-	// enable SPI interface
-	spi.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
+	spi.Bus.CR2.SetBits((conf & stm32.SPI_CR1_SSM_Msk) >> 16)
 }
 
 // Transfer writes/reads a single byte using the SPI interface.
 func (spi SPI) Transfer(w byte) (byte, error) {
-	// Write data to be transmitted to the SPI data register
+
+	// 1. Enable the SPI by setting the SPE bit to 1.
+	// 2. Write the first data item to be transmitted into the SPI_DR register
+	//    (this clears the TXE flag).
+	// 3. Wait until TXE=1 and write the second data item to be transmitted. Then
+	//    wait until RXNE=1 and read the SPI_DR to get the first received data
+	//    item (this clears the RXNE bit). Repeat this operation for each data
+	//    item to be transmitted/received until the n–1 received data.
+	// 4. Wait until RXNE=1 and read the last received data.
+	// 5. Wait until TXE=1 and then wait until BSY=0 before disabling the SPI.
+
+	// put output word (8-bit) in data register (DR), which is parallel-loaded
+	// into shift register, and shifted out on MOSI.
 	spi.Bus.DR.Set(uint32(w))
 
-	// Wait until transmit complete
-	for !spi.Bus.SR.HasBits(stm32.SPI_SR_TXE) {
-	}
-
-	// Wait until receive complete
+	// wait for SPI bus receive buffer not empty bit (RXNE) to be set.
+	// warning: blocks forever until this condition is met.
 	for !spi.Bus.SR.HasBits(stm32.SPI_SR_RXNE) {
 	}
 
-	// Wait until SPI is not busy
+	// copy input word (8-bit) in data register (DR), which was shifted in on MISO
+	// and parallel-loaded into register.
+	data := byte(spi.Bus.DR.Get())
+
+	// wait for SPI bus transmit buffer empty bit (TXE) to be set.
+	// warning: blocks forever until this condition is met.
+	for !spi.Bus.SR.HasBits(stm32.SPI_SR_TXE) {
+	}
+
+	// wait for SPI bus busy bit (BSY) to be clear to indicate synchronous
+	// transfer complete. this will effectively prevent this Transfer() function
+	// from being capable of maintaining high-bandwidth communication throughput,
+	// but it will help guarantee stability on the bus.
 	for spi.Bus.SR.HasBits(stm32.SPI_SR_BSY) {
 	}
 
+	// clear the overrun flag (only in full-duplex mode)
+	if !spi.Bus.CR1.HasBits(stm32.SPI_CR1_RXONLY | stm32.SPI_CR1_BIDIMODE | stm32.SPI_CR1_BIDIOE) {
+		spi.Bus.SR.Get()
+	}
+
 	// Return received data from SPI data register
-	return byte(spi.Bus.DR.Get()), nil
+	return data, nil
 }

src/machine/machine_stm32f4.go

@@ -0,0 +1,229 @@
+// +build stm32f4
+
+package machine
+
+// Peripheral abstraction layer for the stm32f4
+
+import (
+	"device/stm32"
+	"unsafe"
+)
+
+const (
+	PA0  = portA + 0
+	PA1  = portA + 1
+	PA2  = portA + 2
+	PA3  = portA + 3
+	PA4  = portA + 4
+	PA5  = portA + 5
+	PA6  = portA + 6
+	PA7  = portA + 7
+	PA8  = portA + 8
+	PA9  = portA + 9
+	PA10 = portA + 10
+	PA11 = portA + 11
+	PA12 = portA + 12
+	PA13 = portA + 13
+	PA14 = portA + 14
+	PA15 = portA + 15
+
+	PB0  = portB + 0
+	PB1  = portB + 1
+	PB2  = portB + 2
+	PB3  = portB + 3
+	PB4  = portB + 4
+	PB5  = portB + 5
+	PB6  = portB + 6
+	PB7  = portB + 7
+	PB8  = portB + 8
+	PB9  = portB + 9
+	PB10 = portB + 10
+	PB11 = portB + 11
+	PB12 = portB + 12
+	PB13 = portB + 13
+	PB14 = portB + 14
+	PB15 = portB + 15
+
+	PC0  = portC + 0
+	PC1  = portC + 1
+	PC2  = portC + 2
+	PC3  = portC + 3
+	PC4  = portC + 4
+	PC5  = portC + 5
+	PC6  = portC + 6
+	PC7  = portC + 7
+	PC8  = portC + 8
+	PC9  = portC + 9
+	PC10 = portC + 10
+	PC11 = portC + 11
+	PC12 = portC + 12
+	PC13 = portC + 13
+	PC14 = portC + 14
+	PC15 = portC + 15
+
+	PD0  = portD + 0
+	PD1  = portD + 1
+	PD2  = portD + 2
+	PD3  = portD + 3
+	PD4  = portD + 4
+	PD5  = portD + 5
+	PD6  = portD + 6
+	PD7  = portD + 7
+	PD8  = portD + 8
+	PD9  = portD + 9
+	PD10 = portD + 10
+	PD11 = portD + 11
+	PD12 = portD + 12
+	PD13 = portD + 13
+	PD14 = portD + 14
+	PD15 = portD + 15
+
+	PE0  = portE + 0
+	PE1  = portE + 1
+	PE2  = portE + 2
+	PE3  = portE + 3
+	PE4  = portE + 4
+	PE5  = portE + 5
+	PE6  = portE + 6
+	PE7  = portE + 7
+	PE8  = portE + 8
+	PE9  = portE + 9
+	PE10 = portE + 10
+	PE11 = portE + 11
+	PE12 = portE + 12
+	PE13 = portE + 13
+	PE14 = portE + 14
+	PE15 = portE + 15
+
+	PH0 = portH + 0
+	PH1 = portH + 1
+)
+
+func (p Pin) getPort() *stm32.GPIO_Type {
+	switch p / 16 {
+	case 0:
+		return stm32.GPIOA
+	case 1:
+		return stm32.GPIOB
+	case 2:
+		return stm32.GPIOC
+	case 3:
+		return stm32.GPIOD
+	case 4:
+		return stm32.GPIOE
+	case 5:
+		return stm32.GPIOF
+	case 6:
+		return stm32.GPIOG
+	case 7:
+		return stm32.GPIOH
+	case 8:
+		return stm32.GPIOI
+	default:
+		panic("machine: unknown port")
+	}
+}
+
+// enableClock enables the clock for this desired GPIO port.
+func (p Pin) enableClock() {
+	switch p / 16 {
+	case 0:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOAEN)
+	case 1:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOBEN)
+	case 2:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOCEN)
+	case 3:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIODEN)
+	case 4:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOEEN)
+	case 5:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOFEN)
+	case 6:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOGEN)
+	case 7:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOHEN)
+	case 8:
+		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOIEN)
+	default:
+		panic("machine: unknown port")
+	}
+}
+
+// Enable peripheral clock
+func enableAltFuncClock(bus unsafe.Pointer) {
+	switch bus {
+	case unsafe.Pointer(stm32.DAC): // DAC interface clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_DACEN)
+	case unsafe.Pointer(stm32.PWR): // Power interface clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_PWREN)
+	case unsafe.Pointer(stm32.CAN2): // CAN 2 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_CAN2EN)
+	case unsafe.Pointer(stm32.CAN1): // CAN 1 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_CAN1EN)
+	case unsafe.Pointer(stm32.I2C3): // I2C3 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C3EN)
+	case unsafe.Pointer(stm32.I2C2): // I2C2 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C2EN)
+	case unsafe.Pointer(stm32.I2C1): // I2C1 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C1EN)
+	case unsafe.Pointer(stm32.UART5): // UART5 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_UART5EN)
+	case unsafe.Pointer(stm32.UART4): // UART4 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_UART4EN)
+	case unsafe.Pointer(stm32.USART3): // USART3 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART3EN)
+	case unsafe.Pointer(stm32.USART2): // USART2 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART2EN)
+	case unsafe.Pointer(stm32.SPI3): // SPI3 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_SPI3EN)
+	case unsafe.Pointer(stm32.SPI2): // SPI2 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_SPI2EN)
+	case unsafe.Pointer(stm32.WWDG): // Window watchdog clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_WWDGEN)
+	case unsafe.Pointer(stm32.TIM14): // TIM14 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM14EN)
+	case unsafe.Pointer(stm32.TIM13): // TIM13 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM13EN)
+	case unsafe.Pointer(stm32.TIM12): // TIM12 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM12EN)
+	case unsafe.Pointer(stm32.TIM7): // TIM7 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM7EN)
+	case unsafe.Pointer(stm32.TIM6): // TIM6 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM6EN)
+	case unsafe.Pointer(stm32.TIM5): // TIM5 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM5EN)
+	case unsafe.Pointer(stm32.TIM4): // TIM4 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM4EN)
+	case unsafe.Pointer(stm32.TIM3): // TIM3 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM3EN)
+	case unsafe.Pointer(stm32.TIM2): // TIM2 clock enable
+		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM2EN)
+	case unsafe.Pointer(stm32.TIM11): // TIM11 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_TIM11EN)
+	case unsafe.Pointer(stm32.TIM10): // TIM10 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_TIM10EN)
+	case unsafe.Pointer(stm32.TIM9): // TIM9 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_TIM9EN)
+	case unsafe.Pointer(stm32.SYSCFG): // System configuration controller clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SYSCFGEN)
+	case unsafe.Pointer(stm32.SPI1): // SPI1 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SPI1EN)
+	case unsafe.Pointer(stm32.SDIO): // SDIO clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SDIOEN)
+	case unsafe.Pointer(stm32.ADC3): // ADC3 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_ADC3EN)
+	case unsafe.Pointer(stm32.ADC2): // ADC2 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_ADC2EN)
+	case unsafe.Pointer(stm32.ADC1): // ADC1 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_ADC1EN)
+	case unsafe.Pointer(stm32.USART6): // USART6 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_USART6EN)
+	case unsafe.Pointer(stm32.USART1): // USART1 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_USART1EN)
+	case unsafe.Pointer(stm32.TIM8): // TIM8 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_TIM8EN)
+	case unsafe.Pointer(stm32.TIM1): // TIM1 clock enable
+		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_TIM1EN)
+	}
+}

src/machine/machine_stm32f405.go

@@ -0,0 +1,168 @@
+// +build stm32f405
+
+package machine
+
+// Peripheral abstraction layer for the stm32f405
+
+import (
+	"device/stm32"
+	"math/bits"
+	"runtime/interrupt"
+)
+
+func CPUFrequency() uint32 {
+	return 168000000
+}
+
+// -- UART ---------------------------------------------------------------------
+
+type UART struct {
+	Buffer          *RingBuffer
+	Bus             *stm32.USART_Type
+	Interrupt       interrupt.Interrupt
+	AltFuncSelector stm32.AltFunc
+}
+
+func (uart UART) configurePins(config UARTConfig) {
+	// enable the alternate functions on the TX and RX pins
+	config.TX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTTX}, uart.AltFuncSelector)
+	config.RX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTRX}, uart.AltFuncSelector)
+}
+
+func (uart UART) getBaudRateDivisor(baudRate uint32) uint32 {
+	var clock uint32
+	switch uart.Bus {
+	case stm32.USART1, stm32.USART6:
+		clock = CPUFrequency() / 2 // APB2 Frequency
+	case stm32.USART2, stm32.USART3, stm32.UART4, stm32.UART5:
+		clock = CPUFrequency() / 4 // APB1 Frequency
+	}
+	return clock / baudRate
+}
+
+// -- SPI ----------------------------------------------------------------------
+
+type SPI struct {
+	Bus             *stm32.SPI_Type
+	AltFuncSelector stm32.AltFunc
+}
+
+func (spi SPI) configurePins(config SPIConfig) {
+	config.SCK.ConfigureAltFunc(PinConfig{Mode: PinModeSPICLK}, spi.AltFuncSelector)
+	config.SDO.ConfigureAltFunc(PinConfig{Mode: PinModeSPISDO}, spi.AltFuncSelector)
+	config.SDI.ConfigureAltFunc(PinConfig{Mode: PinModeSPISDI}, spi.AltFuncSelector)
+}
+
+func (spi SPI) getBaudRate(config SPIConfig) uint32 {
+	var clock uint32
+	switch spi.Bus {
+	case stm32.SPI1:
+		clock = CPUFrequency() / 2
+	case stm32.SPI2, stm32.SPI3:
+		clock = CPUFrequency() / 4
+	}
+
+	// limit requested frequency to bus frequency and min frequency (DIV256)
+	freq := config.Frequency
+	if min := clock / 256; freq < min {
+		freq = min
+	} else if freq > clock {
+		freq = clock
+	}
+
+	// calculate the exact clock divisor (freq=clock/div -> div=clock/freq).
+	// truncation is fine, since it produces a less-than-or-equal divisor, and
+	// thus a greater-than-or-equal frequency.
+	// divisors only come in consecutive powers of 2, so we can use log2 (or,
+	// equivalently, bits.Len - 1) to convert to respective enum value.
+	div := bits.Len32(clock/freq) - 1
+
+	// but DIV1 (2^0) is not permitted, as the least divisor is DIV2 (2^1), so
+	// subtract 1 from the log2 value, keeping a lower bound of 0
+	if div < 0 {
+		div = 0
+	} else if div > 0 {
+		div--
+	}
+
+	// finally, shift the enumerated value into position for SPI CR1
+	return uint32(div) << stm32.SPI_CR1_BR_Pos
+}
+
+// -- I2C ----------------------------------------------------------------------
+
+type I2C struct {
+	Bus             *stm32.I2C_Type
+	AltFuncSelector stm32.AltFunc
+}
+
+func (i2c I2C) configurePins(config I2CConfig) {
+	config.SCL.ConfigureAltFunc(PinConfig{Mode: PinModeI2CSCL}, i2c.AltFuncSelector)
+	config.SDA.ConfigureAltFunc(PinConfig{Mode: PinModeI2CSDA}, i2c.AltFuncSelector)
+}
+
+func (i2c I2C) getFreqRange(config I2CConfig) uint32 {
+	// all I2C interfaces are on APB1 (42 MHz)
+	clock := CPUFrequency() / 4
+	// convert to MHz
+	clock /= 1000000
+	// must be between 2 MHz (or 4 MHz for fast mode (Fm)) and 50 MHz, inclusive
+	var min, max uint32 = 2, 50
+	if config.Frequency > 10000 {
+		min = 4 // fast mode (Fm)
+	}
+	if clock < min {
+		clock = min
+	} else if clock > max {
+		clock = max
+	}
+	return clock << stm32.I2C_CR2_FREQ_Pos
+}
+
+func (i2c I2C) getRiseTime(config I2CConfig) uint32 {
+	// These bits must be programmed with the maximum SCL rise time given in the
+	// I2C bus specification, incremented by 1.
+	// For instance: in Sm mode, the maximum allowed SCL rise time is 1000 ns.
+	// If, in the I2C_CR2 register, the value of FREQ[5:0] bits is equal to 0x08
+	// and PCLK1 = 125 ns, therefore the TRISE[5:0] bits must be programmed with
+	// 09h (1000 ns / 125 ns = 8 + 1)
+	freqRange := i2c.getFreqRange(config)
+	if config.Frequency > 100000 {
+		// fast mode (Fm) adjustment
+		freqRange *= 300
+		freqRange /= 1000
+	}
+	return (freqRange + 1) << stm32.I2C_TRISE_TRISE_Pos
+}
+
+func (i2c I2C) getSpeed(config I2CConfig) uint32 {
+	ccr := func(pclk uint32, freq uint32, coeff uint32) uint32 {
+		return (((pclk - 1) / (freq * coeff)) + 1) & stm32.I2C_CCR_CCR_Msk
+	}
+	sm := func(pclk uint32, freq uint32) uint32 { // standard mode (Sm)
+		if s := ccr(pclk, freq, 2); s < 4 {
+			return 4
+		} else {
+			return s
+		}
+	}
+	fm := func(pclk uint32, freq uint32, duty uint8) uint32 { // fast mode (Fm)
+		if duty == DutyCycle2 {
+			return ccr(pclk, freq, 3)
+		} else {
+			return ccr(pclk, freq, 25) | stm32.I2C_CCR_DUTY
+		}
+	}
+	// all I2C interfaces are on APB1 (42 MHz)
+	clock := CPUFrequency() / 4
+	if config.Frequency <= 100000 {
+		return sm(clock, config.Frequency)
+	} else {
+		s := fm(clock, config.Frequency, config.DutyCycle)
+		if (s & stm32.I2C_CCR_CCR_Msk) == 0 {
+			return 1
+		} else {
+			return s | stm32.I2C_CCR_F_S
+		}
+	}
+}

src/machine/machine_stm32f407.go

@@ -1,84 +1,18 @@
-// +build stm32,stm32f407
+// +build stm32f407
 
 package machine
 
-// Peripheral abstraction layer for the stm32f4(07)
+// Peripheral abstraction layer for the stm32f407
 
 import (
 	"device/stm32"
 	"runtime/interrupt"
-	"unsafe"
 )
 
 func CPUFrequency() uint32 {
 	return 168000000
 }
 
-func (p Pin) getPort() *stm32.GPIO_Type {
-	switch p / 16 {
-	case 0:
-		return stm32.GPIOA
-	case 1:
-		return stm32.GPIOB
-	case 2:
-		return stm32.GPIOC
-	case 3:
-		return stm32.GPIOD
-	case 4:
-		return stm32.GPIOE
-	case 5:
-		return stm32.GPIOF
-	case 6:
-		return stm32.GPIOG
-	case 7:
-		return stm32.GPIOH
-	case 8:
-		return stm32.GPIOI
-	default:
-		panic("machine: unknown port")
-	}
-}
-
-// enableClock enables the clock for this desired GPIO port.
-func (p Pin) enableClock() {
-	switch p / 16 {
-	case 0:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOAEN)
-	case 1:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOBEN)
-	case 2:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOCEN)
-	case 3:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIODEN)
-	case 4:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOEEN)
-	case 5:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOFEN)
-	case 6:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOGEN)
-	case 7:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOHEN)
-	case 8:
-		stm32.RCC.AHB1ENR.SetBits(stm32.RCC_AHB1ENR_GPIOIEN)
-	default:
-		panic("machine: unknown port")
-	}
-}
-
-// Enable peripheral clock
-func enableAltFuncClock(bus unsafe.Pointer) {
-	switch bus {
-	case unsafe.Pointer(stm32.USART1):
-		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_USART1EN)
-	case unsafe.Pointer(stm32.USART2):
-		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART2EN)
-	case unsafe.Pointer(stm32.I2C1):
-		stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C1EN)
-	case unsafe.Pointer(stm32.SPI1):
-		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SPI1EN)
-	}
-}
-
 //---------- UART related types and code
 
 // UART representation

src/machine/uart.go

@@ -1,4 +1,4 @@
-// +build avr nrf sam sifive stm32 k210 nxp
+// +build avr esp nrf sam sifive stm32 k210 nxp
 
 package machine
 

src/machine/uart_nxpmk66f18.go

@@ -64,7 +64,7 @@ func gosched()
 
 // PutcharUART writes a byte to the UART synchronously, without using interrupts
 // or calling the scheduler
-func PutcharUART(u UART, c byte) {
+func PutcharUART(u *UART, c byte) {
 	// ensure the UART has been configured
 	if !u.SCGC.HasBits(u.SCGCMask) {
 		u.configure(UARTConfig{}, false)
@@ -79,15 +79,13 @@ func PutcharUART(u UART, c byte) {
 
 // PollUART manually checks a UART status and calls the ISR. This should only be
 // called by runtime.abort.
-func PollUART(u UART) {
+func PollUART(u *UART) {
 	if u.SCGC.HasBits(u.SCGCMask) {
 		u.handleStatusInterrupt(u.Interrupt)
 	}
 }
 
-type UART = *UARTData
-
-type UARTData struct {
+type UART struct {
 	*nxp.UART_Type
 	SCGC     *volatile.Register32
 	SCGCMask uint32
@@ -103,11 +101,11 @@ type UARTData struct {
 	Interrupt    interrupt.Interrupt
 }
 
-var UART0 = UARTData{UART_Type: nxp.UART0, SCGC: &nxp.SIM.SCGC4, SCGCMask: nxp.SIM_SCGC4_UART0, DefaultRX: defaultUART0RX, DefaultTX: defaultUART0TX}
-var UART1 = UARTData{UART_Type: nxp.UART1, SCGC: &nxp.SIM.SCGC4, SCGCMask: nxp.SIM_SCGC4_UART1, DefaultRX: defaultUART1RX, DefaultTX: defaultUART1TX}
-var UART2 = UARTData{UART_Type: nxp.UART2, SCGC: &nxp.SIM.SCGC4, SCGCMask: nxp.SIM_SCGC4_UART2, DefaultRX: defaultUART2RX, DefaultTX: defaultUART2TX}
-var UART3 = UARTData{UART_Type: nxp.UART3, SCGC: &nxp.SIM.SCGC4, SCGCMask: nxp.SIM_SCGC4_UART3, DefaultRX: defaultUART3RX, DefaultTX: defaultUART3TX}
-var UART4 = UARTData{UART_Type: nxp.UART4, SCGC: &nxp.SIM.SCGC1, SCGCMask: nxp.SIM_SCGC1_UART4, DefaultRX: defaultUART4RX, DefaultTX: defaultUART4TX}
+var UART0 = UART{UART_Type: nxp.UART0, SCGC: &nxp.SIM.SCGC4, SCGCMask: nxp.SIM_SCGC4_UART0, DefaultRX: defaultUART0RX, DefaultTX: defaultUART0TX}
+var UART1 = UART{UART_Type: nxp.UART1, SCGC: &nxp.SIM.SCGC4, SCGCMask: nxp.SIM_SCGC4_UART1, DefaultRX: defaultUART1RX, DefaultTX: defaultUART1TX}
+var UART2 = UART{UART_Type: nxp.UART2, SCGC: &nxp.SIM.SCGC4, SCGCMask: nxp.SIM_SCGC4_UART2, DefaultRX: defaultUART2RX, DefaultTX: defaultUART2TX}
+var UART3 = UART{UART_Type: nxp.UART3, SCGC: &nxp.SIM.SCGC4, SCGCMask: nxp.SIM_SCGC4_UART3, DefaultRX: defaultUART3RX, DefaultTX: defaultUART3TX}
+var UART4 = UART{UART_Type: nxp.UART4, SCGC: &nxp.SIM.SCGC1, SCGCMask: nxp.SIM_SCGC1_UART4, DefaultRX: defaultUART4RX, DefaultTX: defaultUART4TX}
 
 func init() {
 	UART0.Interrupt = interrupt.New(nxp.IRQ_UART0_RX_TX, UART0.handleStatusInterrupt)
@@ -118,11 +116,11 @@ func init() {
 }
 
 // Configure the UART.
-func (u UART) Configure(config UARTConfig) {
+func (u *UART) Configure(config UARTConfig) {
 	u.configure(config, true)
 }
 
-func (u UART) configure(config UARTConfig, canSched bool) {
+func (u *UART) configure(config UARTConfig, canSched bool) {
 	// from: serial_begin
 
 	if !u.Configured {
@@ -183,7 +181,7 @@ func (u UART) configure(config UARTConfig, canSched bool) {
 	}
 }
 
-func (u UART) Disable() {
+func (u *UART) Disable() {
 	// from: serial_end
 
 	// check if the device has been enabled already
@@ -206,13 +204,13 @@ func (u UART) Disable() {
 	u.Buffer.Clear()
 }
 
-func (u UART) Flush() {
+func (u *UART) Flush() {
 	for u.Transmitting.Get() != 0 {
 		gosched()
 	}
 }
 
-func (u UART) handleStatusInterrupt(interrupt.Interrupt) {
+func (u *UART) handleStatusInterrupt(interrupt.Interrupt) {
 	// from: uart0_status_isr
 
 	// receive
@@ -290,7 +288,7 @@ func (u UART) handleStatusInterrupt(interrupt.Interrupt) {
 }
 
 // WriteByte writes a byte of data to the UART.
-func (u UART) WriteByte(c byte) error {
+func (u *UART) WriteByte(c byte) error {
 	if !u.Configured {
 		return ErrNotConfigured
 	}

src/machine/usb_nrf52840.go

@@ -87,9 +87,12 @@ func exitCriticalSection() {
 
 // Configure the USB CDC interface. The config is here for compatibility with the UART interface.
 func (usbcdc *USBCDC) Configure(config UARTConfig) {
-	// enable IRQ
+	// Enable IRQ. Make sure this is higher than the SWI2 interrupt handler so
+	// that it is possible to print to the console from a BLE interrupt. You
+	// shouldn't generally do that but it is useful for debugging and panic
+	// logging.
 	usbcdc.interrupt = interrupt.New(nrf.IRQ_USBD, USB.handleInterrupt)
-	usbcdc.interrupt.SetPriority(0xD0)
+	usbcdc.interrupt.SetPriority(0x40) // interrupt priority 2 (lower number means more important)
 	usbcdc.interrupt.Enable()
 
 	// enable USB

src/os/env.go

@@ -3,3 +3,7 @@ package os
 func Getenv(key string) string {
 	return ""
 }
+
+func LookupEnv(key string) (string, bool) {
+	return "", false
+}

src/os/file_unix.go

@@ -1,4 +1,4 @@
-// +build darwin linux,!baremetal freebsd,!baremetal
+// +build darwin linux,!baremetal,!wasi freebsd,!baremetal
 
 package os
 

src/reflect/swapper.go

@@ -1,5 +1,40 @@
 package reflect
 
+import "unsafe"
+
+// Some of code here has been copied from the Go sources:
+//   https://github.com/golang/go/blob/go1.15.2/src/reflect/swapper.go
+// It has the following copyright note:
+//
+// 		Copyright 2016 The Go Authors. All rights reserved.
+// 		Use of this source code is governed by a BSD-style
+// 		license that can be found in the LICENSE file.
+
 func Swapper(slice interface{}) func(i, j int) {
-	panic("unimplemented: reflect.Swapper")
+	v := ValueOf(slice)
+	if v.Kind() != Slice {
+		panic(&ValueError{Method: "Swapper"})
+	}
+
+	// Just return Nop func if nothing to swap.
+	if v.Len() < 2 {
+		return func(i, j int) {}
+	}
+
+	typ := v.Type().Elem()
+	size := typ.Size()
+
+	header := (*SliceHeader)(v.value)
+	tmp := unsafe.Pointer(&make([]byte, size)[0])
+
+	return func(i, j int) {
+		if uint(i) >= uint(header.Len) || uint(j) >= uint(header.Len) {
+			panic("reflect: slice index out of range")
+		}
+		val1 := unsafe.Pointer(header.Data + uintptr(i)*size)
+		val2 := unsafe.Pointer(header.Data + uintptr(j)*size)
+		memcpy(tmp, val1, size)
+		memcpy(val1, val2, size)
+		memcpy(val2, tmp, size)
+	}
 }

src/runtime/arch_386.go

@@ -1,5 +1,7 @@
 package runtime
 
+import "device"
+
 const GOARCH = "386"
 
 // The bitness of the CPU (e.g. 8, 32, 64).
@@ -10,4 +12,6 @@ func align(ptr uintptr) uintptr {
 	return (ptr + 3) &^ 3
 }
 
-func getCurrentStackPointer() uintptr
+func getCurrentStackPointer() uintptr {
+	return device.AsmFull("movl %esp, {}", nil)
+}

src/runtime/arch_amd64.go

@@ -1,5 +1,7 @@
 package runtime
 
+import "device"
+
 const GOARCH = "amd64"
 
 // The bitness of the CPU (e.g. 8, 32, 64).
@@ -12,4 +14,6 @@ func align(ptr uintptr) uintptr {
 	return (ptr + 15) &^ 15
 }
 
-func getCurrentStackPointer() uintptr
+func getCurrentStackPointer() uintptr {
+	return device.AsmFull("movq %rsp, {}", nil)
+}

src/runtime/arch_arm.go

@@ -1,4 +1,4 @@
-// +build arm,!baremetal arm,arm7tdmi
+// +build arm,!baremetal,!wasm arm,arm7tdmi
 
 package runtime
 

src/runtime/arch_arm64.go

@@ -1,5 +1,7 @@
 package runtime
 
+import "device/arm"
+
 const GOARCH = "arm64"
 
 // The bitness of the CPU (e.g. 8, 32, 64).
@@ -9,5 +11,6 @@ const TargetBits = 64
 func align(ptr uintptr) uintptr {
 	return (ptr + 7) &^ 7
 }
-
-func getCurrentStackPointer() uintptr
+func getCurrentStackPointer() uintptr {
+	return arm.AsmFull("mov {}, sp", nil)
+}