machine: hide internal pin modes

Many pin modes are only for peripherals like SPI and PWM. Do not make
these part of the public API: the public API is the Configure method on
the peripheral, not the PinMode constant.

.circleci/config.yml

@@ -118,13 +118,7 @@ jobs:
     steps:
       - test-linux:
           llvm: "14"
-  test-llvm14-go119:
+    resource_class: large
-    docker:
-      - image: golang:1.19beta1-buster
-    steps:
-      - test-linux:
-          llvm: "14"
-          fmt-check: false
 
 workflows:
   test-all:
@@ -132,6 +126,3 @@ workflows:
       # This tests our lowest supported versions of Go and LLVM, to make sure at
       # least the smoke tests still pass.
       - test-llvm14-go118
-      # This tests a beta version of Go. It should be removed once regular
-      # release builds are built using this version.
-      - test-llvm14-go119

.github/workflows/build-macos.yml

@@ -16,10 +16,6 @@ jobs:
     name: build-macos
     runs-on: macos-11
     steps:
-      - name: Install Go
-        uses: actions/setup-go@v2
-        with:
-          go-version: '1.18.1'
       - name: Install Dependencies
         shell: bash
         run: |
@@ -35,8 +31,13 @@ jobs:
         uses: actions/checkout@v2
         with:
           submodules: true
+      - name: Install Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: '1.19'
+          cache: true
       - name: Cache LLVM source
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-source
         with:
           key: llvm-source-14-macos-v1
@@ -50,7 +51,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Cache LLVM build
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-build
         with:
           key: llvm-build-14-macos-v1
@@ -68,7 +69,7 @@ jobs:
           make llvm-build
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Cache wasi-libc sysroot
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-wasi-libc
         with:
           key: wasi-libc-sysroot-v4
@@ -104,23 +105,17 @@ jobs:
     name: homebrew-install
     runs-on: macos-latest
     steps:
-      - name: Install Go
-        uses: actions/setup-go@v2
-        with:
-          go-version: '1.18'
       - name: Install LLVM
         shell: bash
         run: |
           HOMEBREW_NO_AUTO_UPDATE=1 brew install llvm@14
       - name: Checkout
         uses: actions/checkout@v2
-      - name: Cache Go
+      - name: Install Go
-        uses: actions/cache@v2
+        uses: actions/setup-go@v3
         with:
-          key: go-cache-macos-homebrew-v1-${{ hashFiles('go.mod') }}
+          go-version: '1.19'
-          path: |
+          cache: true
-            ~/Library/Caches/go-build
-            ~/go/pkg/mod
       - name: Build TinyGo
         run: go install
       - name: Check binary

.github/workflows/linux.yml

@@ -18,14 +18,13 @@ jobs:
     # statically linked binary.
     runs-on: ubuntu-latest
     container:
-      image: alpine:3.16
+      image: golang:1.19-alpine
     steps:
       - name: Install apk dependencies
-        # tar: needed for actions/cache@v2
+        # tar: needed for actions/cache@v3
         # git+openssh: needed for checkout (I think?)
-        # gcompat: needed for go binary
         # ruby: needed to install fpm
-        run: apk add tar git openssh gcompat make g++ ruby
+        run: apk add tar git openssh make g++ ruby
       - name: Work around CVE-2022-24765
         # We're not on a multi-user machine, so this is safe.
         run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
@@ -33,19 +32,15 @@ jobs:
         uses: actions/checkout@v2
         with:
           submodules: true
-      - name: Install Go
-        uses: actions/setup-go@v2
-        with:
-          go-version: '1.18.1'
       - name: Cache Go
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           key: go-cache-linux-alpine-v1-${{ hashFiles('go.mod') }}
           path: |
             ~/.cache/go-build
             ~/go/pkg/mod
       - name: Cache LLVM source
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-source
         with:
           key: llvm-source-14-linux-alpine-v1
@@ -59,7 +54,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Cache LLVM build
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-build
         with:
           key: llvm-build-14-linux-alpine-v1
@@ -77,7 +72,7 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Cache Binaryen
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-binaryen
         with:
           key: binaryen-linux-alpine-v1
@@ -88,7 +83,7 @@ jobs:
           apk add cmake samurai python3
           make binaryen STATIC=1
       - name: Cache wasi-libc
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-wasi-libc
         with:
           key: wasi-libc-sysroot-linux-alpine-v1
@@ -121,9 +116,10 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
       - name: Install Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v3
         with:
-          go-version: '1.18.1'
+          go-version: '1.19'
+          cache: true
       - name: Install wasmtime
         run: |
           curl https://wasmtime.dev/install.sh -sSf | bash
@@ -173,9 +169,10 @@ jobs:
               simavr \
               ninja-build
       - name: Install Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v3
         with:
-          go-version: '1.18.1'
+          go-version: '1.19'
+          cache: true
       - name: Install Node.js
         uses: actions/setup-node@v2
         with:
@@ -184,15 +181,8 @@ jobs:
         run: |
           curl https://wasmtime.dev/install.sh -sSf | bash
           echo "$HOME/.wasmtime/bin" >> $GITHUB_PATH
-      - name: Cache Go
-        uses: actions/cache@v2
-        with:
-          key: go-cache-linux-asserts-v1-${{ hashFiles('go.mod') }}
-          path: |
-            ~/.cache/go-build
-            ~/go/pkg/mod
       - name: Cache LLVM source
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-source
         with:
           key: llvm-source-14-linux-asserts-v2
@@ -206,7 +196,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Cache LLVM build
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-build
         with:
           key: llvm-build-14-linux-asserts-v1
@@ -222,7 +212,7 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Cache Binaryen
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-binaryen
         with:
           key: binaryen-linux-asserts-v1
@@ -231,7 +221,7 @@ jobs:
         if: steps.cache-binaryen.outputs.cache-hit != 'true'
         run: make binaryen
       - name: Cache wasi-libc
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-wasi-libc
         with:
           key: wasi-libc-sysroot-linux-asserts-v5
@@ -279,18 +269,12 @@ jobs:
               g++-arm-linux-gnueabihf \
               libc6-dev-armhf-cross
       - name: Install Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v3
         with:
-          go-version: '1.18.1'
+          go-version: '1.19'
-      - name: Cache Go
+          cache: true
-        uses: actions/cache@v2
-        with:
-          key: go-cache-linux-arm-v2-${{ hashFiles('go.mod') }}
-          path: |
-            ~/.cache/go-build
-            ~/go/pkg/mod
       - name: Cache LLVM source
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-source
         with:
           key: llvm-source-14-linux-v2
@@ -304,7 +288,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Cache LLVM build
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-build
         with:
           key: llvm-build-14-linux-arm-v1
@@ -322,7 +306,7 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Cache Binaryen
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-binaryen
         with:
           key: binaryen-linux-arm-v1
@@ -385,18 +369,12 @@ jobs:
               libc6-dev-arm64-cross \
               ninja-build
       - name: Install Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v3
         with:
-          go-version: '1.18.1'
+          go-version: '1.19'
-      - name: Cache Go
+          cache: true
-        uses: actions/cache@v2
-        with:
-          key: go-cache-linux-arm64-v2-${{ hashFiles('go.mod') }}
-          path: |
-            ~/.cache/go-build
-            ~/go/pkg/mod
       - name: Cache LLVM source
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-source
         with:
           key: llvm-source-14-linux-v1
@@ -410,7 +388,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Cache LLVM build
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-build
         with:
           key: llvm-build-14-linux-arm64-v1
@@ -426,7 +404,7 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Cache Binaryen
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-binaryen
         with:
           key: binaryen-linux-arm64-v1

.github/workflows/windows.yml

@@ -15,10 +15,6 @@ jobs:
   build-windows:
     runs-on: windows-2022
     steps:
-      - name: Install Go
-        uses: actions/setup-go@v2
-        with:
-          go-version: '1.18.1'
       - uses: brechtm/setup-scoop@v2
         with:
           scoop_update: 'false'
@@ -30,15 +26,13 @@ jobs:
         uses: actions/checkout@v2
         with:
           submodules: true
-      - name: Cache Go
+      - name: Install Go
-        uses: actions/cache@v2
+        uses: actions/setup-go@v3
         with:
-          key: go-cache-windows-v1-${{ hashFiles('go.mod') }}
+          go-version: '1.19'
-          path: |
+          cache: true
-            ~/AppData/Local/go-build
-            ~/go/pkg/mod
       - name: Cache LLVM source
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-source
         with:
           key: llvm-source-14-windows-v2
@@ -52,7 +46,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Cache LLVM build
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-llvm-build
         with:
           key: llvm-build-14-windows-v2
@@ -69,7 +63,7 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Cache wasi-libc sysroot
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache-wasi-libc
         with:
           key: wasi-libc-sysroot-v4

Dockerfile

@@ -1,5 +1,5 @@
 # tinygo-llvm stage obtains the llvm source for TinyGo
-FROM golang:1.18 AS tinygo-llvm
+FROM golang:1.19 AS tinygo-llvm
 
 RUN apt-get update && \
     apt-get install -y apt-utils make cmake clang-11 binutils-avr gcc-avr avr-libc ninja-build

Makefile

@@ -326,11 +326,14 @@ TEST_PACKAGES_FAST += crypto/elliptic/internal/fiat
 endif
 
 # archive/zip requires os.ReadAt, which is not yet supported on windows
+# compress/flate appears to hang on wasi
+# compress/lzw appears to hang on wasi
+# crypto/hmac fails on wasi, it exits with a "slice out of range" panic
 # debug/plan9obj requires os.ReadAt, which is not yet supported on windows
-# io/fs requires os.ReadDir, which is not yet supported on windows or wasi
+# io/ioutil requires os.ReadDir, which is not yet supported on windows or wasi
+# strconv requires recover() which is not yet supported on wasi
+# text/template/parse requires recover(), which is not yet supported on wasi
 # testing/fstest requires os.ReadDir, which is not yet supported on windows or wasi
-# compress/flate fails windows go 1.18, https://github.com/tinygo-org/tinygo/issues/2762
-# compress/lzw fails windows go 1.18 wasi, https://github.com/tinygo-org/tinygo/issues/2762
 
 # Additional standard library packages that pass tests on individual platforms
 TEST_PACKAGES_LINUX := \
@@ -340,7 +343,6 @@ TEST_PACKAGES_LINUX := \
 	crypto/hmac \
 	debug/dwarf \
 	debug/plan9obj \
-	io/fs \
 	io/ioutil \
 	strconv \
 	testing/fstest \
@@ -349,7 +351,12 @@ TEST_PACKAGES_LINUX := \
 TEST_PACKAGES_DARWIN := $(TEST_PACKAGES_LINUX)
 
 TEST_PACKAGES_WINDOWS := \
-	compress/lzw
+	compress/flate \
+	compress/lzw \
+	crypto/hmac \
+	strconv \
+	text/template/parse \
+	$(nil)
 
 # Report platforms on which each standard library package is known to pass tests
 jointmp := $(shell echo /tmp/join.$$$$)
@@ -364,12 +371,15 @@ report-stdlib-tests-pass:
 # Standard library packages that pass tests quickly on the current platform
 ifeq ($(shell uname),Darwin)
 TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_DARWIN)
+TEST_IOFS := true
 endif
 ifeq ($(shell uname),Linux)
 TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_LINUX)
+TEST_IOFS := true
 endif
 ifeq ($(OS),Windows_NT)
 TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_WINDOWS)
+TEST_IOFS := false
 endif
 
 # Test known-working standard library packages.
@@ -377,6 +387,12 @@ endif
 .PHONY: tinygo-test
 tinygo-test:
 	$(TINYGO) test $(TEST_PACKAGES_HOST) $(TEST_PACKAGES_SLOW)
+	@# io/fs requires os.ReadDir, not yet supported on windows or wasi. It also
+	@# requires a large stack-size. Hence, io/fs is only run conditionally.
+	@# For more details, see the comments on issue #3143.
+ifeq ($(TEST_IOFS),true)
+	$(TINYGO) test -stack-size=6MB io/fs
+endif
 tinygo-test-fast:
 	$(TINYGO) test $(TEST_PACKAGES_HOST)
 tinygo-bench:
@@ -386,9 +402,9 @@ tinygo-bench-fast:
 
 # Same thing, except for wasi rather than the current platform.
 tinygo-test-wasi:
-	$(TINYGO) test -target wasi $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW)
+	$(TINYGO) test -target wasi $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW) ./tests/runtime_wasi
 tinygo-test-wasi-fast:
-	$(TINYGO) test -target wasi $(TEST_PACKAGES_FAST)
+	$(TINYGO) test -target wasi $(TEST_PACKAGES_FAST) ./tests/runtime_wasi
 tinygo-bench-wasi:
 	$(TINYGO) test -target wasi -bench . $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW)
 tinygo-bench-wasi-fast:
@@ -410,6 +426,7 @@ tinygo-baremetal:
 .PHONY: smoketest
 smoketest:
 	$(TINYGO) version
+	$(TINYGO) targets > /dev/null
 	# regression test for #2892
 	cd tests/testing/recurse && ($(TINYGO) test ./... > recurse.log && cat recurse.log && test $$(wc -l < recurse.log) = 2 && rm recurse.log)
 	# compile-only platform-independent examples
@@ -519,6 +536,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=matrixportal-m4     examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pybadge             examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=metro-m4-airlift    examples/blinky1
@@ -599,7 +618,7 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=challenger-rp2040    examples/blinky1
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=trinkey-qt2040      examples/adc_rp2040
+	$(TINYGO) build -size short -o test.hex -target=trinkey-qt2040      examples/temp
 	@$(MD5SUM) test.hex
 	# test pwm
 	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
@@ -681,7 +700,9 @@ ifneq ($(XTENSA), 0)
 	$(TINYGO) build -size short -o test.bin -target mch2022             examples/serial
 	@$(MD5SUM) test.bin
 endif
-	$(TINYGO) build -size short -o test.bin -target=esp32c3           	examples/serial
+	$(TINYGO) build -size short -o test.bin -target=esp32c3             examples/serial
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-12f         examples/serial
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=m5stamp-c3          examples/serial
 	@$(MD5SUM) test.bin
@@ -689,8 +710,6 @@ endif
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.hex -target=hifive1b            examples/blinky1
 	@$(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
 ifneq ($(WASM), 0)

README.md

@@ -125,7 +125,7 @@ The following 91 microcontroller boards are currently supported:
 * [Seeed LoRa-E5 Development Kit](https://www.seeedstudio.com/LoRa-E5-Dev-Kit-p-4868.html)
 * [Seeed Sipeed MAix BiT](https://www.seeedstudio.com/Sipeed-MAix-BiT-for-RISC-V-AI-IoT-p-2872.html)
 * [Seeed Wio Terminal](https://www.seeedstudio.com/Wio-Terminal-p-4509.html)
-* [SiFIve HiFive1 Rev B](https://www.sifive.com/boards/hifive1)
+* [SiFIve HiFive1 Rev B](https://www.sifive.com/boards/hifive1-rev-b)
 * [Sparkfun Thing Plus RP2040](https://www.sparkfun.com/products/17745)
 * [ST Micro "Nucleo" F103RB](https://www.st.com/en/evaluation-tools/nucleo-f103rb.html)
 * [ST Micro "Nucleo" F722ZE](https://www.st.com/en/evaluation-tools/nucleo-f722ze.html)

builder/build.go

@@ -178,7 +178,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 
 		Scheduler:          config.Scheduler(),
 		AutomaticStackSize: config.AutomaticStackSize(),
-		DefaultStackSize:   config.Target.DefaultStackSize,
+		DefaultStackSize:   config.StackSize(),
 		NeedsStackObjects:  config.NeedsStackObjects(),
 		Debug:              true,
 	}

cgo/cgo.go

@@ -32,6 +32,7 @@ type cgoPackage struct {
 	errors          []error
 	currentDir      string // current working directory
 	packageDir      string // full path to the package to process
+	importPath      string
 	fset            *token.FileSet
 	tokenFiles      map[string]*token.File
 	definedGlobally map[string]ast.Node
@@ -39,12 +40,15 @@ type cgoPackage struct {
 	cflags          []string // CFlags from #cgo lines
 	ldflags         []string // LDFlags from #cgo lines
 	visitedFiles    map[string][]byte
+	cgoHeaders      []string
 }
 
 // cgoFile holds information only for a single Go file (with one or more
 // `import "C"` statements).
 type cgoFile struct {
 	*cgoPackage
+	file    *ast.File
+	index   int
 	defined map[string]ast.Node
 	names   map[string]clangCursor
 }
@@ -158,9 +162,10 @@ func GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 // functions), the CFLAGS and LDFLAGS found in #cgo lines, and a map of file
 // hashes of the accessed C header files. If there is one or more error, it
 // returns these in the []error slice but still modifies the AST.
-func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string, clangHeaders string) (*ast.File, []string, []string, []string, map[string][]byte, []error) {
+func Process(files []*ast.File, dir, importPath string, fset *token.FileSet, cflags []string, clangHeaders string) (*ast.File, []string, []string, []string, map[string][]byte, []error) {
 	p := &cgoPackage{
 		currentDir:      dir,
+		importPath:      importPath,
 		fset:            fset,
 		tokenFiles:      map[string]*token.File{},
 		definedGlobally: map[string]ast.Node{},
@@ -210,13 +215,13 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 		}
 	}
 	// Patch some types, for example *C.char in C.CString.
-	cf := p.newCGoFile()
+	cf := p.newCGoFile(nil, -1) // dummy *cgoFile for the walker
 	astutil.Apply(p.generated, func(cursor *astutil.Cursor) bool {
 		return cf.walker(cursor, nil)
 	}, nil)
 
 	// Find `import "C"` C fragments in the file.
-	cgoHeaders := make([]string, len(files)) // combined CGo header fragment for each file
+	p.cgoHeaders = make([]string, len(files)) // combined CGo header fragment for each file
 	for i, f := range files {
 		var cgoHeader string
 		for i := 0; i < len(f.Decls); i++ {
@@ -275,7 +280,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 			cgoHeader += fragment
 		}
 
-		cgoHeaders[i] = cgoHeader
+		p.cgoHeaders[i] = cgoHeader
 	}
 
 	// Define CFlags that will be used while parsing the package.
@@ -289,7 +294,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 	}
 
 	// Retrieve types such as C.int, C.longlong, etc from C.
-	p.newCGoFile().readNames(builtinAliasTypedefs, cflagsForCGo, "", func(names map[string]clangCursor) {
+	p.newCGoFile(nil, -1).readNames(builtinAliasTypedefs, cflagsForCGo, "", func(names map[string]clangCursor) {
 		gen := &ast.GenDecl{
 			TokPos: token.NoPos,
 			Tok:    token.TYPE,
@@ -303,8 +308,8 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 
 	// Process CGo imports for each file.
 	for i, f := range files {
-		cf := p.newCGoFile()
+		cf := p.newCGoFile(f, i)
-		cf.readNames(cgoHeaders[i], cflagsForCGo, filepath.Base(fset.File(f.Pos()).Name()), func(names map[string]clangCursor) {
+		cf.readNames(p.cgoHeaders[i], cflagsForCGo, filepath.Base(fset.File(f.Pos()).Name()), func(names map[string]clangCursor) {
 			for _, name := range builtinAliases {
 				// Names such as C.int should not be obtained from C.
 				// This works around an issue in picolibc that has `#define int`
@@ -320,12 +325,14 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 	// Print the newly generated in-memory AST, for debugging.
 	//ast.Print(fset, p.generated)
 
-	return p.generated, cgoHeaders, p.cflags, p.ldflags, p.visitedFiles, p.errors
+	return p.generated, p.cgoHeaders, p.cflags, p.ldflags, p.visitedFiles, p.errors
 }
 
-func (p *cgoPackage) newCGoFile() *cgoFile {
+func (p *cgoPackage) newCGoFile(file *ast.File, index int) *cgoFile {
 	return &cgoFile{
 		cgoPackage: p,
+		file:       file,
+		index:      index,
 		defined:    make(map[string]ast.Node),
 		names:      make(map[string]clangCursor),
 	}
@@ -1117,8 +1124,11 @@ func (f *cgoFile) getASTDeclName(name string, found clangCursor, iscall bool) st
 		return alias
 	}
 	node := f.getASTDeclNode(name, found, iscall)
-	if _, ok := node.(*ast.FuncDecl); ok && !iscall {
+	if node, ok := node.(*ast.FuncDecl); ok {
-		return "C." + name + "$funcaddr"
+		if !iscall {
+			return node.Name.Name + "$funcaddr"
+		}
+		return node.Name.Name
 	}
 	return "C." + name
 }
@@ -1142,7 +1152,7 @@ func (f *cgoFile) getASTDeclNode(name string, found clangCursor, iscall bool) as
 			// Original cgo reports an error like
 			//   cgo: inconsistent definitions for C.myint
 			// which is far less helpful.
-			f.addError(getPos(node), "defined previously at "+f.fset.Position(getPos(newNode)).String()+" with a different type")
+			f.addError(getPos(node), name+" defined previously at "+f.fset.Position(getPos(newNode)).String()+" with a different type")
 		}
 		f.defined[name] = node
 		return node
@@ -1150,11 +1160,39 @@ func (f *cgoFile) getASTDeclNode(name string, found clangCursor, iscall bool) as
 
 	// The declaration has no AST node. Create it now.
 	f.defined[name] = nil
-	node, elaboratedType := f.createASTNode(name, found)
+	node, extra := f.createASTNode(name, found)
 	f.defined[name] = node
-	f.definedGlobally[name] = node
 	switch node := node.(type) {
 	case *ast.FuncDecl:
+		if strings.HasPrefix(node.Doc.List[0].Text, "//export _Cgo_static_") {
+			// Static function. Only accessible in the current Go file.
+			globalName := strings.TrimPrefix(node.Doc.List[0].Text, "//export ")
+			// Make an alias. Normally this is done using the alias function
+			// attribute, but MacOS for some reason doesn't support this (even
+			// though the linker has support for aliases in the form of N_INDR).
+			// Therefore, create an actual function for MacOS.
+			var params []string
+			for _, param := range node.Type.Params.List {
+				params = append(params, param.Names[0].Name)
+			}
+			callInst := fmt.Sprintf("%s(%s);", name, strings.Join(params, ", "))
+			if node.Type.Results != nil {
+				callInst = "return " + callInst
+			}
+			aliasDeclaration := fmt.Sprintf(`
+#ifdef __APPLE__
+%s {
+	%s
+}
+#else
+extern __typeof(%s) %s __attribute__((alias(%#v)));
+#endif
+`, extra.(string), callInst, name, globalName, name)
+			f.cgoHeaders[f.index] += "\n\n" + aliasDeclaration
+		} else {
+			// Regular (non-static) function.
+			f.definedGlobally[name] = node
+		}
 		f.generated.Decls = append(f.generated.Decls, node)
 		// Also add a declaration like the following:
 		//   var C.foo$funcaddr unsafe.Pointer
@@ -1162,7 +1200,7 @@ func (f *cgoFile) getASTDeclNode(name string, found clangCursor, iscall bool) as
 			Tok: token.VAR,
 			Specs: []ast.Spec{
 				&ast.ValueSpec{
-					Names: []*ast.Ident{{Name: "C." + name + "$funcaddr"}},
+					Names: []*ast.Ident{{Name: node.Name.Name + "$funcaddr"}},
 					Type: &ast.SelectorExpr{
 						X:   &ast.Ident{Name: "unsafe"},
 						Sel: &ast.Ident{Name: "Pointer"},
@@ -1171,8 +1209,10 @@ func (f *cgoFile) getASTDeclNode(name string, found clangCursor, iscall bool) as
 			},
 		})
 	case *ast.GenDecl:
+		f.definedGlobally[name] = node
 		f.generated.Decls = append(f.generated.Decls, node)
 	case *ast.TypeSpec:
+		f.definedGlobally[name] = node
 		f.generated.Decls = append(f.generated.Decls, &ast.GenDecl{
 			Tok:   token.TYPE,
 			Specs: []ast.Spec{node},
@@ -1186,7 +1226,8 @@ func (f *cgoFile) getASTDeclNode(name string, found clangCursor, iscall bool) as
 
 	// If this is a struct or union it may need bitfields or union accessor
 	// methods.
-	if elaboratedType != nil {
+	switch elaboratedType := extra.(type) {
+	case *elaboratedTypeInfo:
 		// Add struct bitfields.
 		for _, bitfield := range elaboratedType.bitfields {
 			f.createBitfieldGetter(bitfield, "C."+name)

cgo/cgo_test.go

@@ -48,7 +48,7 @@ func TestCGo(t *testing.T) {
 			}
 
 			// Process the AST with CGo.
-			cgoAST, _, _, _, _, cgoErrors := Process([]*ast.File{f}, "testdata", fset, cflags, "")
+			cgoAST, _, _, _, _, cgoErrors := Process([]*ast.File{f}, "testdata", "main", fset, cflags, "")
 
 			// Check the AST for type errors.
 			var typecheckErrors []error

cgo/libclang.go

@@ -4,7 +4,9 @@ package cgo
 // modification. It does not touch the AST itself.
 
 import (
+	"crypto/sha256"
 	"crypto/sha512"
+	"encoding/hex"
 	"fmt"
 	"go/ast"
 	"go/scanner"
@@ -43,6 +45,8 @@ typedef struct {
 GoCXCursor tinygo_clang_getTranslationUnitCursor(CXTranslationUnit tu);
 unsigned tinygo_clang_visitChildren(GoCXCursor parent, CXCursorVisitor visitor, CXClientData client_data);
 CXString tinygo_clang_getCursorSpelling(GoCXCursor c);
+CXString tinygo_clang_getCursorPrettyPrinted(GoCXCursor c, CXPrintingPolicy Policy);
+CXPrintingPolicy tinygo_clang_getCursorPrintingPolicy(GoCXCursor c);
 enum CXCursorKind tinygo_clang_getCursorKind(GoCXCursor c);
 CXType tinygo_clang_getCursorType(GoCXCursor c);
 GoCXCursor tinygo_clang_getTypeDeclaration(CXType t);
@@ -50,6 +54,7 @@ CXType tinygo_clang_getTypedefDeclUnderlyingType(GoCXCursor c);
 CXType tinygo_clang_getCursorResultType(GoCXCursor c);
 int tinygo_clang_Cursor_getNumArguments(GoCXCursor c);
 GoCXCursor tinygo_clang_Cursor_getArgument(GoCXCursor c, unsigned i);
+enum CX_StorageClass tinygo_clang_Cursor_getStorageClass(GoCXCursor c);
 CXSourceLocation tinygo_clang_getCursorLocation(GoCXCursor c);
 CXSourceRange tinygo_clang_getCursorExtent(GoCXCursor c);
 CXTranslationUnit tinygo_clang_Cursor_getTranslationUnit(GoCXCursor c);
@@ -189,7 +194,7 @@ func (f *cgoFile) readNames(fragment string, cflags []string, filename string, c
 
 // Convert the AST node under the given Clang cursor to a Go AST node and return
 // it.
-func (f *cgoFile) createASTNode(name string, c clangCursor) (ast.Node, *elaboratedTypeInfo) {
+func (f *cgoFile) createASTNode(name string, c clangCursor) (ast.Node, any) {
 	kind := C.tinygo_clang_getCursorKind(c)
 	pos := f.getCursorPosition(c)
 	switch kind {
@@ -200,19 +205,43 @@ func (f *cgoFile) createASTNode(name string, c clangCursor) (ast.Node, *elaborat
 			Kind: ast.Fun,
 			Name: "C." + name,
 		}
+		exportName := name
+		localName := name
+		var stringSignature string
+		if C.tinygo_clang_Cursor_getStorageClass(c) == C.CX_SC_Static {
+			// A static function is assigned a globally unique symbol name based
+			// on the file path (like _Cgo_static_2d09198adbf58f4f4655_foo) and
+			// has a different Go name in the form of C.foo!symbols.go instead
+			// of just C.foo.
+			path := f.importPath + "/" + filepath.Base(f.fset.File(f.file.Pos()).Name())
+			staticIDBuf := sha256.Sum256([]byte(path))
+			staticID := hex.EncodeToString(staticIDBuf[:10])
+			exportName = "_Cgo_static_" + staticID + "_" + name
+			localName = name + "!" + filepath.Base(path)
+
+			// Create a signature. This is necessary for MacOS to forward the
+			// call, because MacOS doesn't support aliases like ELF and PE do.
+			// (There is N_INDR but __attribute__((alias("..."))) doesn't work).
+			policy := C.tinygo_clang_getCursorPrintingPolicy(c)
+			defer C.clang_PrintingPolicy_dispose(policy)
+			C.clang_PrintingPolicy_setProperty(policy, C.CXPrintingPolicy_TerseOutput, 1)
+			stringSignature = getString(C.tinygo_clang_getCursorPrettyPrinted(c, policy))
+			stringSignature = strings.Replace(stringSignature, " "+name+"(", " "+exportName+"(", 1)
+			stringSignature = strings.TrimPrefix(stringSignature, "static ")
+		}
 		args := make([]*ast.Field, numArgs)
 		decl := &ast.FuncDecl{
 			Doc: &ast.CommentGroup{
 				List: []*ast.Comment{
 					{
 						Slash: pos - 1,
-						Text:  "//export " + name,
+						Text:  "//export " + exportName,
 					},
 				},
 			},
 			Name: &ast.Ident{
 				NamePos: pos,
-				Name:    "C." + name,
+				Name:    "C." + localName,
 				Obj:     obj,
 			},
 			Type: &ast.FuncType{
@@ -263,7 +292,7 @@ func (f *cgoFile) createASTNode(name string, c clangCursor) (ast.Node, *elaborat
 			}
 		}
 		obj.Decl = decl
-		return decl, nil
+		return decl, stringSignature
 	case C.CXCursor_StructDecl, C.CXCursor_UnionDecl:
 		typ := f.makeASTRecordType(c, pos)
 		typeName := "C." + name

cgo/libclang_stubs.c

@@ -17,6 +17,14 @@ CXString tinygo_clang_getCursorSpelling(CXCursor c) {
 	return clang_getCursorSpelling(c);
 }
 
+CXString tinygo_clang_getCursorPrettyPrinted(CXCursor c, CXPrintingPolicy policy) {
+	return clang_getCursorPrettyPrinted(c, policy);
+}
+
+CXPrintingPolicy tinygo_clang_getCursorPrintingPolicy(CXCursor c) {
+	return clang_getCursorPrintingPolicy(c);
+}
+
 enum CXCursorKind tinygo_clang_getCursorKind(CXCursor c) {
 	return clang_getCursorKind(c);
 }
@@ -45,6 +53,10 @@ CXCursor tinygo_clang_Cursor_getArgument(CXCursor c, unsigned i) {
 	return clang_Cursor_getArgument(c, i);
 }
 
+enum CX_StorageClass tinygo_clang_Cursor_getStorageClass(CXCursor c) {
+	return clang_Cursor_getStorageClass(c);
+}
+
 CXSourceLocation tinygo_clang_getCursorLocation(CXCursor c) {
 	return clang_getCursorLocation(c);
 }

cgo/testdata/symbols.go

@@ -5,6 +5,7 @@ package main
 int foo(int a, int b);
 void variadic0();
 void variadic2(int x, int y, ...);
+static void staticfunc(int x);
 
 // Global variable signatures.
 extern int someValue;
@@ -16,6 +17,7 @@ func accessFunctions() {
 	C.foo(3, 4)
 	C.variadic0()
 	C.variadic2(3, 5)
+	C.staticfunc(3)
 }
 
 func accessGlobals() {

cgo/testdata/symbols.out.go

@@ -55,5 +55,10 @@ func C.variadic2(x C.int, y C.int)
 
 var C.variadic2$funcaddr unsafe.Pointer
 
+//export _Cgo_static_173c95a79b6df1980521_staticfunc
+func C.staticfunc!symbols.go(x C.int)
+
+var C.staticfunc!symbols.go$funcaddr unsafe.Pointer
+
 //go:extern someValue
 var C.someValue C.int

compileopts/config.go

@@ -175,6 +175,15 @@ func (c *Config) AutomaticStackSize() bool {
 	return false
 }
 
+// StackSize returns the default stack size to be used for goroutines, if the
+// stack size could not be determined automatically at compile time.
+func (c *Config) StackSize() uint64 {
+	if c.Options.StackSize != 0 {
+		return c.Options.StackSize
+	}
+	return c.Target.DefaultStackSize
+}
+
 // UseThinLTO returns whether ThinLTO should be used for the given target. Some
 // targets (such as wasm) are not yet supported.
 // We should try and remove as many exceptions as possible in the future, so
@@ -457,7 +466,14 @@ func (c *Config) OpenOCDConfiguration() (args []string, err error) {
 		args = append(args, "-c", cmd)
 	}
 	if c.Target.OpenOCDTransport != "" {
-		args = append(args, "-c", "transport select "+c.Target.OpenOCDTransport)
+		transport := c.Target.OpenOCDTransport
+		if transport == "swd" {
+			switch openocdInterface {
+			case "stlink-dap":
+				transport = "dapdirect_swd"
+			}
+		}
+		args = append(args, "-c", "transport select "+transport)
 	}
 	args = append(args, "-f", "target/"+c.Target.OpenOCDTarget+".cfg")
 	return args, nil

compileopts/options.go

@@ -28,6 +28,7 @@ type Options struct {
 	GC              string
 	PanicStrategy   string
 	Scheduler       string
+	StackSize       uint64 // goroutine stack size (if none could be automatically determined)
 	Serial          string
 	Work            bool // -work flag to print temporary build directory
 	InterpTimeout   time.Duration
@@ -49,6 +50,8 @@ type Options struct {
 	LLVMFeatures    string
 	Directory       string
 	PrintJSON       bool
+	Monitor         bool
+	BaudRate        int
 }
 
 // Verify performs a validation on the given options, raising an error if options are not valid.

compileopts/target.go

@@ -65,7 +65,7 @@ type TargetSpec struct {
 }
 
 // overrideProperties overrides all properties that are set in child into itself using reflection.
-func (spec *TargetSpec) overrideProperties(child *TargetSpec) {
+func (spec *TargetSpec) overrideProperties(child *TargetSpec) error {
 	specType := reflect.TypeOf(spec).Elem()
 	specValue := reflect.ValueOf(spec).Elem()
 	childValue := reflect.ValueOf(child).Elem()
@@ -95,14 +95,15 @@ func (spec *TargetSpec) overrideProperties(child *TargetSpec) {
 				for j := i + 1; j < dst.Len(); j++ {
 					w := dst.Index(j).String()
 					if v == w {
-						panic("duplicate value '" + v + "' in field : " + field.Name)
+						return fmt.Errorf("duplicate value '%s' in field %s", v, field.Name)
 					}
 				}
 			}
 		default:
-			panic("unknown field type : " + kind.String())
+			return fmt.Errorf("unknown field type: %s", kind)
 		}
 	}
+	return nil
 }
 
 // load reads a target specification from the JSON in the given io.Reader. It
@@ -117,10 +118,10 @@ func (spec *TargetSpec) load(r io.Reader) error {
 }
 
 // loadFromGivenStr loads the TargetSpec from the given string that could be:
-// - targets/ directory inside the compiler sources
+//   - targets/ directory inside the compiler sources
-// - a relative or absolute path to custom (project specific) target specification .json file;
+//   - a relative or absolute path to custom (project specific) target specification .json file;
-//   the Inherits[] could contain the files from target folder (ex. stm32f4disco)
+//     the Inherits[] could contain the files from target folder (ex. stm32f4disco)
-//   as well as path to custom files (ex. myAwesomeProject.json)
+//     as well as path to custom files (ex. myAwesomeProject.json)
 func (spec *TargetSpec) loadFromGivenStr(str string) error {
 	path := ""
 	if strings.HasSuffix(str, ".json") {
@@ -150,11 +151,17 @@ func (spec *TargetSpec) resolveInherits() error {
 		if err != nil {
 			return err
 		}
-		newSpec.overrideProperties(subtarget)
+		err = newSpec.overrideProperties(subtarget)
+		if err != nil {
+			return err
+		}
 	}
 
 	// When all properties are loaded, make sure they are properly inherited.
-	newSpec.overrideProperties(spec)
+	err := newSpec.overrideProperties(spec)
+	if err != nil {
+		return err
+	}
 	*spec = *newSpec
 
 	return nil
@@ -221,7 +228,7 @@ func LoadTarget(options *Options) (*TargetSpec, error) {
 	// it includes all parents as specified in the "inherits" key.
 	err = spec.resolveInherits()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("%s : %w", options.Target, err)
 	}
 
 	if spec.Scheduler == "asyncify" {

compiler/compiler_test.go

@@ -79,7 +79,7 @@ func TestCompiler(t *testing.T) {
 				RelocationModel:    config.RelocationModel(),
 				Scheduler:          config.Scheduler(),
 				AutomaticStackSize: config.AutomaticStackSize(),
-				DefaultStackSize:   config.Target.DefaultStackSize,
+				DefaultStackSize:   config.StackSize(),
 				NeedsStackObjects:  config.NeedsStackObjects(),
 			}
 			machine, err := NewTargetMachine(compilerConfig)

compiler/symbol.go

@@ -163,18 +163,20 @@ func (c *compilerContext) getFunction(fn *ssa.Function) llvm.Value {
 	// External/exported functions may not retain pointer values.
 	// https://golang.org/cmd/cgo/#hdr-Passing_pointers
 	if info.exported {
-		// Set the wasm-import-module attribute if the function's module is set.
+		if c.archFamily() == "wasm32" {
-		if info.module != "" {
-
 			// We need to add the wasm-import-module and the wasm-import-name
-			wasmImportModuleAttr := c.ctx.CreateStringAttribute("wasm-import-module", info.module)
+			// attributes.
-			llvmFn.AddFunctionAttr(wasmImportModuleAttr)
+			module := info.module
-
+			if module == "" {
-			// Add the Wasm Import Name, if we are a named wasm import
+				module = "env"
-			if info.importName != "" {
-				wasmImportNameAttr := c.ctx.CreateStringAttribute("wasm-import-name", info.importName)
-				llvmFn.AddFunctionAttr(wasmImportNameAttr)
 			}
+			llvmFn.AddFunctionAttr(c.ctx.CreateStringAttribute("wasm-import-module", module))
+
+			name := info.importName
+			if name == "" {
+				name = info.linkName
+			}
+			llvmFn.AddFunctionAttr(c.ctx.CreateStringAttribute("wasm-import-name", name))
 		}
 		nocaptureKind := llvm.AttributeKindID("nocapture")
 		nocapture := c.ctx.CreateEnumAttribute(nocaptureKind, 0)

compiler/testdata/pragma.ll

@@ -62,7 +62,7 @@ declare void @main.undefinedFunctionNotInSection(i8*) #0
 
 attributes #0 = { "target-features"="+bulk-memory,+nontrapping-fptoint,+sign-ext" }
 attributes #1 = { nounwind "target-features"="+bulk-memory,+nontrapping-fptoint,+sign-ext" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+nontrapping-fptoint,+sign-ext" "wasm-export-name"="extern_func" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+nontrapping-fptoint,+sign-ext" "wasm-export-name"="extern_func" "wasm-import-module"="env" "wasm-import-name"="extern_func" }
 attributes #3 = { inlinehint nounwind "target-features"="+bulk-memory,+nontrapping-fptoint,+sign-ext" }
 attributes #4 = { noinline nounwind "target-features"="+bulk-memory,+nontrapping-fptoint,+sign-ext" }
-attributes #5 = { nounwind "target-features"="+bulk-memory,+nontrapping-fptoint,+sign-ext" "wasm-export-name"="exportedFunctionInSection" }
+attributes #5 = { nounwind "target-features"="+bulk-memory,+nontrapping-fptoint,+sign-ext" "wasm-export-name"="exportedFunctionInSection" "wasm-import-module"="env" "wasm-import-name"="exportedFunctionInSection" }

go.mod

@@ -9,8 +9,10 @@ require (
 	github.com/chromedp/chromedp v0.7.6
 	github.com/gofrs/flock v0.8.1
 	github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf
+	github.com/inhies/go-bytesize v0.0.0-20220417184213-4913239db9cf
 	github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892
 	github.com/mattn/go-colorable v0.1.8
+	github.com/mattn/go-tty v0.0.4
 	go.bug.st/serial v1.3.5
 	golang.org/x/sys v0.0.0-20220829200755-d48e67d00261
 	golang.org/x/tools v0.1.11

go.sum

@@ -12,7 +12,6 @@ github.com/chromedp/sysutil v1.0.0/go.mod h1:kgWmDdq8fTzXYcKIBqIYvRRTnYb9aNS9moA
 github.com/creack/goselect v0.1.2 h1:2DNy14+JPjRBgPzAd1thbQp4BSIihxcBf0IXhQXDRa0=
 github.com/creack/goselect v0.1.2/go.mod h1:a/NhLweNvqIYMuxcMOuWY516Cimucms3DglDzQP3hKY=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gobwas/httphead v0.1.0 h1:exrUm0f4YX0L7EBwZHuCF4GDp8aJfVeBrlLQrs6NqWU=
 github.com/gobwas/httphead v0.1.0/go.mod h1:O/RXo79gxV8G+RqlR/otEwx4Q36zl9rqC5u12GKvMCM=
 github.com/gobwas/pool v0.2.1 h1:xfeeEhW7pwmX8nuLVlqbzVc7udMDrwetjEv+TZIz1og=
@@ -23,44 +22,47 @@ github.com/gofrs/flock v0.8.1 h1:+gYjHKf32LDeiEEFhQaotPbLuUXjY5ZqxKgXy7n59aw=
 github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
 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/inhies/go-bytesize v0.0.0-20220417184213-4913239db9cf h1:FtEj8sfIcaaBfAKrE1Cwb61YDtYq9JxChK1c7AKce7s=
+github.com/inhies/go-bytesize v0.0.0-20220417184213-4913239db9cf/go.mod h1:yrqSXGoD/4EKfF26AOGzscPOgTTJcyAwM2rpixWT+t4=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
 github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
 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/mattn/go-colorable v0.1.4/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
 github.com/mattn/go-colorable v0.1.8 h1:c1ghPdyEDarC70ftn0y+A/Ee++9zz8ljHG1b13eJ0s8=
 github.com/mattn/go-colorable v0.1.8/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
+github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/mattn/go-isatty v0.0.10/go.mod h1:qgIWMr58cqv1PHHyhnkY9lrL7etaEgOFcMEpPG5Rm84=
 github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
+github.com/mattn/go-runewidth v0.0.7/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
+github.com/mattn/go-tty v0.0.4 h1:NVikla9X8MN0SQAqCYzpGyXv0jY7MNl3HOWD2dkle7E=
+github.com/mattn/go-tty v0.0.4/go.mod h1:u5GGXBtZU6RQoKV8gY5W6UhMudbR5vXnUe7j3pxse28=
 github.com/orisano/pixelmatch v0.0.0-20210112091706-4fa4c7ba91d5 h1:1SoBaSPudixRecmlHXb/GxmaD3fLMtHIDN13QujwQuc=
 github.com/orisano/pixelmatch v0.0.0-20210112091706-4fa4c7ba91d5/go.mod h1:nZgzbfBr3hhjoZnS66nKrHmduYNpc34ny7RK4z5/HM0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
-github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
-go.bug.st/serial v1.1.3 h1:YEBxJa9pKS9Wdg46B/jiaKbvvbUrjhZZZITfJHEJhaE=
-go.bug.st/serial v1.1.3/go.mod h1:8TT7u/SwwNIpJ8QaG4s+HTjFt9ReXs2cdOU7ZEk50Dk=
 go.bug.st/serial v1.3.5 h1:k50SqGZCnHZ2MiBQgzccXWG+kd/XpOs1jUljpDDKzaE=
 go.bug.st/serial v1.3.5/go.mod h1:z8CesKorE90Qr/oRSJiEuvzYRKol9r/anJZEb5kt304=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 h1:6zppjxzCulZykYSLyVDYbneBfbaBIQPYMevg0bEwv2s=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200909081042-eff7692f9009/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201207223542-d4d67f95c62d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20211124211545-fe61309f8881/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220114195835-da31bd327af9 h1:XfKQ4OlFl8okEOr5UvAqFRVj8pY/4yfcXrddB8qAbU0=
-golang.org/x/sys v0.0.0-20220114195835-da31bd327af9/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220829200755-d48e67d00261 h1:v6hYoSR9T5oet+pMXwUWkbiVqx/63mlHjefrHmxwfeY=
 golang.org/x/sys v0.0.0-20220829200755-d48e67d00261/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/tools v0.1.11 h1:loJ25fNOEhSXfHrpoGj91eCUThwdNX6u24rO1xnNteY=
 golang.org/x/tools v0.1.11/go.mod h1:SgwaegtQh8clINPpECJMqnxLv9I09HLqnW3RMqW0CA4=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 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=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 tinygo.org/x/go-llvm v0.0.0-20220802112859-5bb0b77907a7 h1:nSLR52mUw7DPQQVA3ZJFH63zjU4ME84fKiin6mdnYWc=
 tinygo.org/x/go-llvm v0.0.0-20220802112859-5bb0b77907a7/go.mod h1:GFbusT2VTA4I+l4j80b17KFK+6whv69Wtny5U+T8RR0=

interp/interpreter.go

@@ -369,6 +369,11 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				nBytes := uint32(operands[3].Uint())
 				dstObj := mem.getWritable(dst.index())
 				dstBuf := dstObj.buffer.asRawValue(r)
+				if mem.get(src.index()).buffer == nil {
+					// Looks like the source buffer is not defined.
+					// This can happen with //extern or //go:embed.
+					return nil, mem, r.errorAt(inst, errUnsupportedRuntimeInst)
+				}
 				srcBuf := mem.get(src.index()).buffer.asRawValue(r)
 				copy(dstBuf.buf[dst.offset():dst.offset()+nBytes], srcBuf.buf[src.offset():])
 				dstObj.buffer = dstBuf

loader/loader.go

@@ -440,7 +440,7 @@ func (p *Package) parseFiles() ([]*ast.File, error) {
 		var initialCFlags []string
 		initialCFlags = append(initialCFlags, p.program.config.CFlags()...)
 		initialCFlags = append(initialCFlags, "-I"+p.Dir)
-		generated, headerCode, cflags, ldflags, accessedFiles, errs := cgo.Process(files, p.program.workingDir, p.program.fset, initialCFlags, p.program.clangHeaders)
+		generated, headerCode, cflags, ldflags, accessedFiles, errs := cgo.Process(files, p.program.workingDir, p.ImportPath, p.program.fset, initialCFlags, p.program.clangHeaders)
 		p.CFlags = append(initialCFlags, cflags...)
 		p.CGoHeaders = headerCode
 		for path, hash := range accessedFiles {

main.go

@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"github.com/google/shlex"
+	"github.com/inhies/go-bytesize"
 	"github.com/mattn/go-colorable"
 	"github.com/tinygo-org/tinygo/builder"
 	"github.com/tinygo-org/tinygo/compileopts"
@@ -243,17 +244,36 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 		// Tests are always run in the package directory.
 		cmd.Dir = result.MainDir
 
-		// Wasmtime needs a few extra flags to work.
+		// wasmtime is the default emulator used for `-target=wasi`. wasmtime
+		// is a WebAssembly runtime CLI with WASI enabled by default. However,
+		// only stdio are allowed by default. For example, while STDOUT routes
+		// to the host, other files don't. It also does not inherit environment
+		// variables from the host. Some tests read testdata files, often from
+		// outside the package directory. Other tests require temporary
+		// writeable directories. We allow this by adding wasmtime flags below.
 		if config.EmulatorName() == "wasmtime" {
-			// Add directories to the module root, but skip the current working
+			// At this point, The current working directory is at the package
-			// directory which is already added by buildAndRun.
+			// directory. Ex. $GOROOT/src/compress/flate for compress/flate.
+			// buildAndRun has already added arguments for wasmtime, that allow
+			// read-access to files such as "testdata/huffman-zero.in".
+			//
+			// Ex. main(.wasm) --dir=. -- -test.v
+
+			// Below adds additional wasmtime flags in case a test reads files
+			// outside its directory, like "../testdata/e.txt". This allows any
+			// relative directory up to the module root, even if the test never
+			// reads any files.
+			//
+			// Ex. --dir=.. --dir=../.. --dir=../../..
 			dirs := dirsToModuleRoot(result.MainDir, result.ModuleRoot)
 			var args []string
 			for _, d := range dirs[1:] {
 				args = append(args, "--dir="+d)
 			}
 
-			// create a new temp directory just for this run, announce it to os.TempDir() via TMPDIR
+			// Some tests create temp directories using os.MkdirTemp or via
+			// t.TempDir(). Create a writeable directory and map it to the
+			// default tempDir environment variable: TMPDIR.
 			tmpdir, err := os.MkdirTemp("", "tinygotmp")
 			if err != nil {
 				return fmt.Errorf("failed to create temporary directory: %w", err)
@@ -262,7 +282,8 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 			// TODO: add option to not delete temp dir for debugging?
 			defer os.RemoveAll(tmpdir)
 
-			// Insert new argments at the front of the command line argments.
+			// The below re-organizes the arguments so that the current
+			// directory is added last.
 			args = append(args, cmd.Args[1:]...)
 			cmd.Args = append(cmd.Args[:1:1], args...)
 		}
@@ -402,7 +423,6 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			if err != nil {
 				return &commandError{"failed to flash", result.Binary, err}
 			}
-			return nil
 		case "msd":
 			switch fileExt {
 			case ".uf2":
@@ -410,13 +430,11 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 				if err != nil {
 					return &commandError{"failed to flash", result.Binary, err}
 				}
-				return nil
 			case ".hex":
 				err := flashHexUsingMSD(config.Target.FlashVolume, result.Binary, config.Options)
 				if err != nil {
 					return &commandError{"failed to flash", result.Binary, err}
 				}
-				return nil
 			default:
 				return errors.New("mass storage device flashing currently only supports uf2 and hex")
 			}
@@ -437,7 +455,6 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			if err != nil {
 				return &commandError{"failed to flash", result.Binary, err}
 			}
-			return nil
 		case "bmp":
 			gdb, err := config.Target.LookupGDB()
 			if err != nil {
@@ -456,10 +473,13 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			if err != nil {
 				return &commandError{"failed to flash", result.Binary, err}
 			}
-			return nil
 		default:
 			return fmt.Errorf("unknown flash method: %s", flashMethod)
 		}
+		if options.Monitor {
+			return Monitor("", options)
+		}
+		return nil
 	})
 }
 
@@ -978,7 +998,8 @@ func getDefaultPort(portFlag string, usbInterfaces []string) (port string, err e
 			preferredPortIDs = append(preferredPortIDs, [2]uint16{uint16(vid), uint16(pid)})
 		}
 
-		var primaryPorts []string // ports picked from preferred USB VID/PID
+		var primaryPorts []string   // ports picked from preferred USB VID/PID
+		var secondaryPorts []string // other ports (as a fallback)
 		for _, p := range portsList {
 			if !p.IsUSB {
 				continue
@@ -1000,6 +1021,8 @@ func getDefaultPort(portFlag string, usbInterfaces []string) (port string, err e
 					continue
 				}
 			}
+
+			secondaryPorts = append(secondaryPorts, p.Name)
 		}
 		if len(primaryPorts) == 1 {
 			// There is exactly one match in the set of preferred ports. Use
@@ -1011,18 +1034,10 @@ func getDefaultPort(portFlag string, usbInterfaces []string) (port string, err e
 			// one device of the same type are connected (e.g. two Arduino
 			// Unos).
 			ports = primaryPorts
-		}
+		} else {
-
+			// No preferred ports found. Fall back to other serial ports
-		if len(ports) == 0 {
+			// available in the system.
-			// fallback
+			ports = secondaryPorts
-			switch runtime.GOOS {
-			case "darwin":
-				ports, err = filepath.Glob("/dev/cu.usb*")
-			case "linux":
-				ports, err = filepath.Glob("/dev/ttyACM*")
-			case "windows":
-				ports, err = serial.GetPortsList()
-			}
 		}
 	default:
 		return "", errors.New("unable to search for a default USB device to be flashed on this OS")
@@ -1037,7 +1052,9 @@ func getDefaultPort(portFlag string, usbInterfaces []string) (port string, err e
 	}
 
 	if len(portCandidates) == 0 {
-		if len(ports) == 1 {
+		if len(usbInterfaces) > 0 {
+			return "", errors.New("unable to search for a default USB device - use -port flag, available ports are " + strings.Join(ports, ", "))
+		} else if len(ports) == 1 {
 			return ports[0], nil
 		} else {
 			return "", errors.New("multiple serial ports available - use -port flag, available ports are " + strings.Join(ports, ", "))
@@ -1102,6 +1119,7 @@ func usage(command string) {
 		fmt.Fprintln(os.Stderr, "  flash:   compile and flash to the device")
 		fmt.Fprintln(os.Stderr, "  gdb:     run/flash and immediately enter GDB")
 		fmt.Fprintln(os.Stderr, "  lldb:    run/flash and immediately enter LLDB")
+		fmt.Fprintln(os.Stderr, "  monitor: open communication port")
 		fmt.Fprintln(os.Stderr, "  env:     list environment variables used during build")
 		fmt.Fprintln(os.Stderr, "  list:    run go list using the TinyGo root")
 		fmt.Fprintln(os.Stderr, "  clean:   empty cache directory ("+goenv.Get("GOCACHE")+")")
@@ -1298,6 +1316,12 @@ func main() {
 	var tags buildutil.TagsFlag
 	flag.Var(&tags, "tags", "a space-separated list of extra build tags")
 	target := flag.String("target", "", "chip/board name or JSON target specification file")
+	var stackSize uint64
+	flag.Func("stack-size", "goroutine stack size (if unknown at compile time)", func(s string) error {
+		size, err := bytesize.Parse(s)
+		stackSize = uint64(size)
+		return err
+	})
 	printSize := flag.String("size", "", "print sizes (none, short, full)")
 	printStacks := flag.Bool("print-stacks", false, "print stack sizes of goroutines")
 	printAllocsString := flag.String("print-allocs", "", "regular expression of functions for which heap allocations should be printed")
@@ -1312,6 +1336,8 @@ func main() {
 	wasmAbi := flag.String("wasm-abi", "", "WebAssembly ABI conventions: js (no i64 params) or generic")
 	llvmFeatures := flag.String("llvm-features", "", "comma separated LLVM features to enable")
 	cpuprofile := flag.String("cpuprofile", "", "cpuprofile output")
+	monitor := flag.Bool("monitor", false, "enable serial monitor")
+	baudrate := flag.Int("baudrate", 115200, "baudrate of serial monitor")
 
 	var flagJSON, flagDeps, flagTest bool
 	if command == "help" || command == "list" || command == "info" || command == "build" {
@@ -1378,6 +1404,7 @@ func main() {
 		GOARCH:          goenv.Get("GOARCH"),
 		GOARM:           goenv.Get("GOARM"),
 		Target:          *target,
+		StackSize:       stackSize,
 		Opt:             *opt,
 		GC:              *gc,
 		PanicStrategy:   *panicStrategy,
@@ -1400,6 +1427,8 @@ func main() {
 		OpenOCDCommands: ocdCommands,
 		LLVMFeatures:    *llvmFeatures,
 		PrintJSON:       flagJSON,
+		Monitor:         *monitor,
+		BaudRate:        *baudrate,
 	}
 	if *printCommands {
 		options.PrintCommands = printCommand
@@ -1590,6 +1619,9 @@ func main() {
 			fmt.Println("FAIL")
 			os.Exit(1)
 		}
+	case "monitor":
+		err := Monitor(*port, options)
+		handleCompilerError(err)
 	case "targets":
 		dir := filepath.Join(goenv.Get("TINYGOROOT"), "targets")
 		entries, err := ioutil.ReadDir(dir)

monitor.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"time"
+
+	"github.com/mattn/go-tty"
+	"github.com/tinygo-org/tinygo/builder"
+	"github.com/tinygo-org/tinygo/compileopts"
+	"go.bug.st/serial"
+)
+
+// Monitor connects to the given port and reads/writes the serial port.
+func Monitor(port string, options *compileopts.Options) error {
+	config, err := builder.NewConfig(options)
+	if err != nil {
+		return err
+	}
+
+	wait := 300
+	for i := 0; i <= wait; i++ {
+		port, err = getDefaultPort(port, config.Target.SerialPort)
+		if err != nil {
+			if i < wait {
+				time.Sleep(10 * time.Millisecond)
+				continue
+			}
+			return err
+		}
+		break
+	}
+
+	br := options.BaudRate
+	if br <= 0 {
+		br = 115200
+	}
+
+	wait = 300
+	var p serial.Port
+	for i := 0; i <= wait; i++ {
+		p, err = serial.Open(port, &serial.Mode{BaudRate: br})
+		if err != nil {
+			if i < wait {
+				time.Sleep(10 * time.Millisecond)
+				continue
+			}
+			return err
+		}
+		break
+	}
+	defer p.Close()
+
+	tty, err := tty.Open()
+	if err != nil {
+		return err
+	}
+	defer tty.Close()
+
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, os.Interrupt)
+	defer signal.Stop(sig)
+
+	go func() {
+		<-sig
+		tty.Close()
+		os.Exit(0)
+	}()
+
+	fmt.Printf("Connected to %s. Press Ctrl-C to exit.\n", port)
+
+	errCh := make(chan error, 1)
+
+	go func() {
+		buf := make([]byte, 100*1024)
+		for {
+			n, err := p.Read(buf)
+			if err != nil {
+				errCh <- fmt.Errorf("read error: %w", err)
+				return
+			}
+
+			if n == 0 {
+				continue
+			}
+			fmt.Printf("%v", string(buf[:n]))
+		}
+	}()
+
+	go func() {
+		for {
+			r, err := tty.ReadRune()
+			if err != nil {
+				errCh <- err
+				return
+			}
+			if r == 0 {
+				continue
+			}
+			p.Write([]byte(string(r)))
+		}
+	}()
+
+	return <-errCh
+}

src/crypto/rand/rand_baremetal.go

@@ -1,5 +1,5 @@
-//go:build stm32 || (sam && atsamd51) || (sam && atsame5x)
+//go:build nrf || stm32 || (sam && atsamd51) || (sam && atsame5x)
-// +build stm32 sam,atsamd51 sam,atsame5x
+// +build nrf stm32 sam,atsamd51 sam,atsame5x
 
 package rand
 

src/examples/adc_rp2040/adc.go

@@ -1,49 +0,0 @@
-// Reads multiple rp2040 ADC channels concurrently. Including the internal temperature sensor
-
-package main
-
-import (
-	"fmt"
-	"machine"
-	"time"
-)
-
-type celsius float32
-
-func (c celsius) String() string {
-	return fmt.Sprintf("%4.1f℃", c)
-}
-
-// rp2040 ADC is 12 bits. Reading are shifted <<4 to fill the 16-bit range.
-var adcReading [3]uint16
-
-func readADC(a machine.ADC, w time.Duration, i int) {
-	for {
-		adcReading[i] = a.Get()
-		time.Sleep(w)
-	}
-}
-
-func main() {
-	machine.InitADC()
-	a0 := machine.ADC{machine.ADC0} // GPIO26 input
-	a1 := machine.ADC{machine.ADC1} // GPIO27 input
-	a2 := machine.ADC{machine.ADC2} // GPIO28 input
-	t := machine.ADC_TEMP_SENSOR    // Internal Temperature sensor
-	// Configure sets the GPIOs to PinAnalog mode
-	a0.Configure(machine.ADCConfig{})
-	a1.Configure(machine.ADCConfig{})
-	a2.Configure(machine.ADCConfig{})
-	// Configure powers on the temperature sensor
-	t.Configure(machine.ADCConfig{})
-
-	// Safe to read concurrently
-	go readADC(a0, 10*time.Millisecond, 0)
-	go readADC(a1, 17*time.Millisecond, 1)
-	go readADC(a2, 29*time.Millisecond, 2)
-
-	for {
-		fmt.Printf("ADC0: %5d ADC1: %5d ADC2: %5d Temp: %v\n\r", adcReading[0], adcReading[1], adcReading[2], celsius(float32(t.ReadTemperature())/1000))
-		time.Sleep(1000 * time.Millisecond)
-	}
-}

src/examples/temp/temp.go

@@ -0,0 +1,23 @@
+// Read the internal temperature sensor of the chip.
+
+package main
+
+import (
+	"fmt"
+	"machine"
+	"time"
+)
+
+type celsius float32
+
+func (c celsius) String() string {
+	return fmt.Sprintf("%4.1f℃", c)
+}
+
+func main() {
+	for {
+		temp := celsius(float32(machine.ReadTemperature()) / 1000)
+		println("temperature:", temp.String())
+		time.Sleep(time.Second)
+	}
+}

src/examples/wasm/README.md

@@ -21,12 +21,14 @@ $ tinygo build -o ./wasm.wasm -target wasm ./main/main.go
 This creates a `wasm.wasm` file, which we can load in JavaScript and execute in
 a browser.
 
-This examples folder contains two examples that can be built using `make`:
+Next, choose which example you want to use:
-
+* [callback](callback): Defines and configures callbacks in Wasm.
-```bash
+* [export](export): Defines callbacks in Wasm, but configures them in JavaScript.
-$ make export
+* [invoke](invoke): Invokes a function defined in JavaScript from Wasm.
-```
+* [main](main): Prints a message to the JavaScript console from Wasm.
+* [slices](slices): Splits an Array defined in JavaScript from Wasm.
 
+Let's say you chose [main](main), you'd build it like so:
 ```bash
 $ make main
 ```
@@ -42,12 +44,8 @@ Serving ./html on http://localhost:8080
 
 Use your web browser to visit http://localhost:8080.
 
-* The wasm "export" example displays a simple math equation using HTML, with
+* Tip: Open the browser development tools (e.g. Right-click, Inspect in
-the result calculated dynamically using WebAssembly.  Changing any of the
+  FireFox) to see console output.
-values on the left hand side triggers the exported wasm `update` function to
-recalculate the result.
-* The wasm "main" example uses `println` to write to your browser JavaScript
-console. You may need to open the browser development tools console to see it.
 
 ## How it works
 

src/examples/wasm/callback/wasm.go

@@ -8,10 +8,12 @@ import (
 var a, b int
 
 func main() {
+	wait := make(chan struct{}, 0)
 	document := js.Global().Get("document")
 	document.Call("getElementById", "a").Set("oninput", updater(&a))
 	document.Call("getElementById", "b").Set("oninput", updater(&b))
 	update()
+	<-wait
 }
 
 func updater(n *int) js.Func {

src/internal/task/task_asyncify_wasm.S

@@ -2,12 +2,16 @@
 
 .functype start_unwind (i32) -> ()
 .import_module start_unwind, asyncify
+.import_name start_unwind, start_unwind
 .functype stop_unwind () -> ()
 .import_module stop_unwind, asyncify
+.import_name stop_unwind, stop_unwind
 .functype start_rewind (i32) -> ()
 .import_module start_rewind, asyncify
+.import_name start_rewind, start_rewind
 .functype stop_rewind () -> ()
 .import_module stop_rewind, asyncify
+.import_name stop_rewind, stop_rewind
 
 .global  tinygo_unwind
 .hidden  tinygo_unwind

src/internal/task/task_stack_amd64_windows.S

@@ -1,5 +1,8 @@
 // Windows on amd64 has a slightly different ABI than other (*nix) systems.
 // Therefore, assembly functions need to be tweaked slightly.
+//
+// The calling convention is described here:
+// https://docs.microsoft.com/en-us/cpp/build/x64-calling-convention?view=msvc-170
 
 .section .text.tinygo_startTask,"ax"
 .global  tinygo_startTask
@@ -17,8 +20,9 @@ tinygo_startTask:
     // Branch to the "goroutine start" function.
     callq *%r12
 
-    // After return, exit this goroutine. This is a tail call.
+    // After return, exit this goroutine.
-    jmp tinygo_pause
+    // This has to be a call, not a jump, to keep the stack correctly aligned.
+    callq tinygo_pause
 
 .global tinygo_swapTask
 .section .text.tinygo_swapTask,"ax"
@@ -35,6 +39,17 @@ tinygo_swapTask:
     pushq %rsi
     pushq %rdi
     pushq %rbp
+    sub   $160, %rsp
+    movaps  %xmm6, 144(%rsp)
+    movaps  %xmm7, 128(%rsp)
+    movaps  %xmm8, 112(%rsp)
+    movaps  %xmm9,  96(%rsp)
+    movaps  %xmm10, 80(%rsp)
+    movaps  %xmm11, 64(%rsp)
+    movaps  %xmm12, 48(%rsp)
+    movaps  %xmm13, 32(%rsp)
+    movaps  %xmm14, 16(%rsp)
+    movaps  %xmm15,  0(%rsp)
     pushq %rbx
 
     // Save the current stack pointer in oldStack.
@@ -45,6 +60,17 @@ tinygo_swapTask:
 
     // Load saved register from the new stack.
     popq %rbx
+    movaps 0(%rsp),   %xmm15
+    movaps 16(%rsp),  %xmm14
+    movaps 32(%rsp),  %xmm13
+    movaps 48(%rsp),  %xmm12
+    movaps 64(%rsp),  %xmm11
+    movaps 80(%rsp),  %xmm10
+    movaps 96(%rsp),  %xmm9
+    movaps 112(%rsp), %xmm8
+    movaps 128(%rsp), %xmm7
+    movaps 144(%rsp), %xmm6
+    add   $160, %rsp
     popq %rbp
     popq %rdi
     popq %rsi

src/internal/task/task_stack_amd64_windows.go

@@ -13,15 +13,34 @@ var systemStack uintptr
 // calleeSavedRegs is the list of registers that must be saved and restored when
 // switching between tasks. Also see task_stack_amd64_windows.S that relies on
 // the exact layout of this struct.
+// The calling convention is described here:
+// https://docs.microsoft.com/en-us/cpp/build/x64-calling-convention?view=msvc-170
+// Most importantly, these are the registers we need to save/restore:
+//
+// > The x64 ABI considers registers RBX, RBP, RDI, RSI, RSP, R12, R13, R14,
+// > R15, and XMM6-XMM15 nonvolatile. They must be saved and restored by a
+// > function that uses them.
 type calleeSavedRegs struct {
-	rbx uintptr
+	// Note: rbx is placed here so that the stack is correctly aligned when
-	rbp uintptr
+	// loading/storing the xmm registers.
-	rdi uintptr
+	rbx   uintptr
-	rsi uintptr
+	xmm15 [2]uint64
-	r12 uintptr
+	xmm14 [2]uint64
-	r13 uintptr
+	xmm13 [2]uint64
-	r14 uintptr
+	xmm12 [2]uint64
-	r15 uintptr
+	xmm11 [2]uint64
+	xmm10 [2]uint64
+	xmm9  [2]uint64
+	xmm8  [2]uint64
+	xmm7  [2]uint64
+	xmm6  [2]uint64
+	rbp   uintptr
+	rdi   uintptr
+	rsi   uintptr
+	r12   uintptr
+	r13   uintptr
+	r14   uintptr
+	r15   uintptr
 
 	pc uintptr
 }

src/machine/board_arduino_mkr1000.go

@@ -7,7 +7,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0x07738135
+const resetMagicValue = 0x07738135
 
 // GPIO Pins
 const (

src/machine/board_arduino_mkrwifi1010.go

@@ -7,7 +7,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0x07738135
+const resetMagicValue = 0x07738135
 
 // GPIO Pins
 const (

src/machine/board_arduino_nano33.go

@@ -7,7 +7,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0x07738135
+const resetMagicValue = 0x07738135
 
 // GPIO Pins
 const (

src/machine/board_arduino_zero.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0x07738135
+const resetMagicValue = 0x07738135
 
 // GPIO Pins - Digital Low
 const (

src/machine/board_atmega328p.go

@@ -12,9 +12,9 @@ const (
 
 const (
 	PB0 = portB + 0
-	PB1 = portB + 1
+	PB1 = portB + 1 // peripherals: Timer1 channel A
-	PB2 = portB + 2
+	PB2 = portB + 2 // peripherals: Timer1 channel B
-	PB3 = portB + 3
+	PB3 = portB + 3 // peripherals: Timer2 channel A
 	PB4 = portB + 4
 	PB5 = portB + 5
 	PB6 = portB + 6
@@ -30,9 +30,9 @@ const (
 	PD0 = portD + 0
 	PD1 = portD + 1
 	PD2 = portD + 2
-	PD3 = portD + 3
+	PD3 = portD + 3 // peripherals: Timer2 channel B
 	PD4 = portD + 4
-	PD5 = portD + 5
+	PD5 = portD + 5 // peripherals: Timer0 channel B
-	PD6 = portD + 6
+	PD6 = portD + 6 // peripherals: Timer0 channel A
 	PD7 = portD + 7
 )

src/machine/board_atsamd21.go

@@ -10,38 +10,38 @@ func CPUFrequency() uint32 {
 
 // Hardware pins
 const (
-	PA00 Pin = 0
+	PA00 Pin = 0 // peripherals: TCC2 channel 0
-	PA01 Pin = 1
+	PA01 Pin = 1 // peripherals: TCC2 channel 1
 	PA02 Pin = 2
 	PA03 Pin = 3
-	PA04 Pin = 4
+	PA04 Pin = 4  // peripherals: TCC0 channel 0
-	PA05 Pin = 5
+	PA05 Pin = 5  // peripherals: TCC0 channel 1
-	PA06 Pin = 6
+	PA06 Pin = 6  // peripherals: TCC1 channel 0
-	PA07 Pin = 7
+	PA07 Pin = 7  // peripherals: TCC1 channel 1
-	PA08 Pin = 8
+	PA08 Pin = 8  // peripherals: TCC0 channel 0, TCC1 channel 2
-	PA09 Pin = 9
+	PA09 Pin = 9  // peripherals: TCC0 channel 1, TCC1 channel 3
-	PA10 Pin = 10
+	PA10 Pin = 10 // peripherals: TCC1 channel 0, TCC0 channel 2
-	PA11 Pin = 11
+	PA11 Pin = 11 // peripherals: TCC1 channel 1, TCC0 channel 3
-	PA12 Pin = 12
+	PA12 Pin = 12 // peripherals: TCC2 channel 0, TCC0 channel 2
-	PA13 Pin = 13
+	PA13 Pin = 13 // peripherals: TCC2 channel 1, TCC0 channel 3
-	PA14 Pin = 14
+	PA14 Pin = 14 // peripherals: TCC0 channel 0
-	PA15 Pin = 15
+	PA15 Pin = 15 // peripherals: TCC0 channel 1
-	PA16 Pin = 16
+	PA16 Pin = 16 // peripherals: TCC2 channel 0, TCC0 channel 2
-	PA17 Pin = 17
+	PA17 Pin = 17 // peripherals: TCC2 channel 1, TCC0 channel 3
-	PA18 Pin = 18
+	PA18 Pin = 18 // peripherals: TCC0 channel 2
-	PA19 Pin = 19
+	PA19 Pin = 19 // peripherals: TCC0 channel 3
-	PA20 Pin = 20
+	PA20 Pin = 20 // peripherals: TCC0 channel 2
-	PA21 Pin = 21
+	PA21 Pin = 21 // peripherals: TCC0 channel 3
-	PA22 Pin = 22
+	PA22 Pin = 22 // peripherals: TCC0 channel 0
-	PA23 Pin = 23
+	PA23 Pin = 23 // peripherals: TCC0 channel 1
-	PA24 Pin = 24
+	PA24 Pin = 24 // peripherals: TCC1 channel 2
-	PA25 Pin = 25
+	PA25 Pin = 25 // peripherals: TCC1 channel 3
 	PA26 Pin = 26
 	PA27 Pin = 27
 	PA28 Pin = 28
 	PA29 Pin = 29
-	PA30 Pin = 30
+	PA30 Pin = 30 // peripherals: TCC1 channel 0
-	PA31 Pin = 31
+	PA31 Pin = 31 // peripherals: TCC1 channel 1
 	PB00 Pin = 32
 	PB01 Pin = 33
 	PB02 Pin = 34
@@ -52,14 +52,14 @@ const (
 	PB07 Pin = 39
 	PB08 Pin = 40
 	PB09 Pin = 41
-	PB10 Pin = 42
+	PB10 Pin = 42 // peripherals: TCC0 channel 0
-	PB11 Pin = 43
+	PB11 Pin = 43 // peripherals: TCC0 channel 1
-	PB12 Pin = 44
+	PB12 Pin = 44 // peripherals: TCC0 channel 2
-	PB13 Pin = 45
+	PB13 Pin = 45 // peripherals: TCC0 channel 3
 	PB14 Pin = 46
 	PB15 Pin = 47
-	PB16 Pin = 48
+	PB16 Pin = 48 // peripherals: TCC0 channel 0
-	PB17 Pin = 49
+	PB17 Pin = 49 // peripherals: TCC0 channel 1
 	PB18 Pin = 50
 	PB19 Pin = 51
 	PB20 Pin = 52
@@ -72,6 +72,6 @@ const (
 	PB27 Pin = 59
 	PB28 Pin = 60
 	PB29 Pin = 61
-	PB30 Pin = 62
+	PB30 Pin = 62 // peripherals: TCC0 channel 0, TCC1 channel 2
-	PB31 Pin = 63
+	PB31 Pin = 63 // peripherals: TCC0 channel 1, TCC1 channel 3
 )

src/machine/board_atsame54-xpro.go

@@ -8,7 +8,7 @@ import (
 )
 
 // Definition for compatibility, but not used
-const RESET_MAGIC_VALUE = 0x00000000
+const resetMagicValue = 0x00000000
 
 const (
 	LED    = PC18

src/machine/board_circuitplay_express.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_feather-m0.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_feather-m4-can.go

@@ -8,7 +8,7 @@ import (
 )
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_feather-m4.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_grandcentral-m4.go

@@ -245,7 +245,7 @@ const (
 
 // Other peripheral constants
 const (
-	RESET_MAGIC_VALUE = 0xF01669EF // Used to reset into bootloader
+	resetMagicValue = 0xF01669EF // Used to reset into bootloader
 )
 
 // USB CDC pins

src/machine/board_itsybitsy-m0.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_itsybitsy-m4.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_matrixportal-m4.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xF01669EF
+const resetMagicValue = 0xF01669EF
 
 // Digital pins
 const (

src/machine/board_metro-m4-airlift.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_p1am-100.go

@@ -7,7 +7,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0x07738135
+const resetMagicValue = 0x07738135
 
 // Note: On the P1AM-100, pins D8, D9, D10, A3, and A4 are used for
 // communication with the base controller.

src/machine/board_pybadge.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_pygamer.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_pyportal.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_qtpy.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_qtpy_rp2040.go

@@ -36,10 +36,9 @@ const (
 )
 
 const (
-	NEOPIXELS       = GPIO12
+	NEOPIXEL       = GPIO12
-	WS2812          = GPIO12
+	WS2812         = GPIO12
-	NEOPIXELS_POWER = GPIO11
+	NEOPIXEL_POWER = GPIO11
-	LED             = GPIO20
 )
 
 // I2C Pins.
@@ -116,5 +115,5 @@ const (
 
 var (
 	usb_VID uint16 = 0x239A
-	usb_PID uint16 = 0x80F1
+	usb_PID uint16 = 0x80F7
 )

src/machine/board_trinket.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/board_wioterminal.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 const (
 	ADC0 = A0

src/machine/board_xiao-ble.go

@@ -104,7 +104,7 @@ const (
 
 var (
 	usb_VID uint16 = 0x2886
-	usb_PID uint16 = 0x0045
+	usb_PID uint16 = 0x8045
 )
 
 var (

src/machine/board_xiao.go

@@ -4,7 +4,7 @@
 package machine
 
 // used to reset into bootloader
-const RESET_MAGIC_VALUE = 0xf01669ef
+const resetMagicValue = 0xf01669ef
 
 // GPIO Pins
 const (

src/machine/i2c.go

@@ -8,6 +8,8 @@ import (
 )
 
 // TWI_FREQ is the I2C bus speed. Normally either 100 kHz, or 400 kHz for high-speed bus.
+//
+// Deprecated: use 100 * machine.KHz or 400 * machine.KHz instead.
 const (
 	TWI_FREQ_100KHZ = 100000
 	TWI_FREQ_400KHZ = 400000

src/machine/machine.go

@@ -18,6 +18,13 @@ var (
 // particular chip but instead runs in WebAssembly for example.
 const Device = deviceName
 
+// Generic constants.
+const (
+	KHz = 1000
+	MHz = 1000_000
+	GHz = 1000_000_000
+)
+
 // PinMode sets the direction and pull mode of the pin. For example, PinOutput
 // sets the pin as an output and PinInputPullup sets the pin as an input with a
 // pull-up.

src/machine/machine_atmega.go

@@ -26,7 +26,7 @@ type I2CConfig struct {
 func (i2c *I2C) Configure(config I2CConfig) error {
 	// Default I2C bus speed is 100 kHz.
 	if config.Frequency == 0 {
-		config.Frequency = TWI_FREQ_100KHZ
+		config.Frequency = 100 * KHz
 	}
 
 	// Activate internal pullups for twi.

src/machine/machine_atmega1280.go

@@ -38,10 +38,10 @@ const (
 	PB1 = portB + 1
 	PB2 = portB + 2
 	PB3 = portB + 3
-	PB4 = portB + 4
+	PB4 = portB + 4 // peripherals: Timer2 channel A
-	PB5 = portB + 5
+	PB5 = portB + 5 // peripherals: Timer1 channel A
-	PB6 = portB + 6
+	PB6 = portB + 6 // peripherals: Timer1 channel B
-	PB7 = portB + 7
+	PB7 = portB + 7 // peripherals: Timer0 channel A
 	PC0 = portC + 0
 	PC1 = portC + 1
 	PC2 = portC + 2
@@ -57,9 +57,9 @@ const (
 	PD7 = portD + 7
 	PE0 = portE + 0
 	PE1 = portE + 1
-	PE3 = portE + 3
+	PE3 = portE + 3 // peripherals: Timer3 channel A
-	PE4 = portE + 4
+	PE4 = portE + 4 // peripherals: Timer3 channel B
-	PE5 = portE + 5
+	PE5 = portE + 5 // peripherals: Timer3 channel C
 	PE6 = portE + 6
 	PF0 = portF + 0
 	PF1 = portF + 1
@@ -72,13 +72,13 @@ const (
 	PG0 = portG + 0
 	PG1 = portG + 1
 	PG2 = portG + 2
-	PG5 = portG + 5
+	PG5 = portG + 5 // peripherals: Timer0 channel B
 	PH0 = portH + 0
 	PH1 = portH + 1
-	PH3 = portH + 3
+	PH3 = portH + 3 // peripherals: Timer4 channel A
-	PH4 = portH + 4
+	PH4 = portH + 4 // peripherals: Timer4 channel B
-	PH5 = portH + 5
+	PH5 = portH + 5 // peripherals: Timer4 channel C
-	PH6 = portH + 6
+	PH6 = portH + 6 // peripherals: Timer0 channel B
 	PJ0 = portJ + 0
 	PJ1 = portJ + 1
 	PK0 = portK + 0
@@ -92,9 +92,9 @@ const (
 	PL0 = portL + 0
 	PL1 = portL + 1
 	PL2 = portL + 2
-	PL3 = portL + 3
+	PL3 = portL + 3 // peripherals: Timer5 channel A
-	PL4 = portL + 4
+	PL4 = portL + 4 // peripherals: Timer5 channel B
-	PL5 = portL + 5
+	PL5 = portL + 5 // peripherals: Timer5 channel C
 	PL6 = portL + 6
 	PL7 = portL + 7
 )

src/machine/machine_atsamd21.go

@@ -10,7 +10,6 @@ package machine
 import (
 	"device/arm"
 	"device/sam"
-	"errors"
 	"runtime/interrupt"
 	"unsafe"
 )
@@ -18,20 +17,20 @@ import (
 const deviceName = sam.Device
 
 const (
-	PinAnalog    PinMode = 1
-	PinSERCOM    PinMode = 2
-	PinSERCOMAlt PinMode = 3
-	PinTimer     PinMode = 4
-	PinTimerAlt  PinMode = 5
-	PinCom       PinMode = 6
-	//PinAC_CLK        PinMode = 7
-	PinDigital       PinMode = 8
 	PinInput         PinMode = 9
 	PinInputPullup   PinMode = 10
 	PinOutput        PinMode = 11
-	PinTCC           PinMode = PinTimer
-	PinTCCAlt        PinMode = PinTimerAlt
 	PinInputPulldown PinMode = 12
+
+	// internal pin modes
+	pinAnalog    PinMode = 1
+	pinSERCOM    PinMode = 2
+	pinSERCOMAlt PinMode = 3
+	pinTCC       PinMode = 4
+	pinTCCAlt    PinMode = 5
+	pinCom       PinMode = 6
+	//PinAC_CLK        PinMode = 7
+	pinDigital PinMode = 8
 )
 
 type PinChange uint8
@@ -150,7 +149,7 @@ func findPinPadMapping(sercom uint8, pin Pin) (pinMode PinMode, pad uint32, ok b
 	if upper != 0 {
 		// SERCOM
 		if (upper>>1)-1 == sercom {
-			pinMode = PinSERCOM
+			pinMode = pinSERCOM
 			pad |= uint32((upper & 1) << 1)
 			ok = true
 		}
@@ -158,7 +157,7 @@ func findPinPadMapping(sercom uint8, pin Pin) (pinMode PinMode, pad uint32, ok b
 	if lower != 0 {
 		// SERCOM-ALT
 		if (lower>>1)-1 == sercom {
-			pinMode = PinSERCOMAlt
+			pinMode = pinSERCOMAlt
 			pad |= uint32((lower & 1) << 1)
 			ok = true
 		}
@@ -382,7 +381,7 @@ func (a ADC) Configure(config ADCConfig) {
 	// 1/2 VDDANA = 0.5 * 3V3 = 1.65V
 	sam.ADC.REFCTRL.SetBits(sam.ADC_REFCTRL_REFSEL_INTVCC1 << sam.ADC_REFCTRL_REFSEL_Pos)
 
-	a.Pin.Configure(PinConfig{Mode: PinAnalog})
+	a.Pin.Configure(PinConfig{Mode: pinAnalog})
 	return
 }
 
@@ -677,7 +676,7 @@ const i2cTimeout = 1000
 func (i2c *I2C) Configure(config I2CConfig) error {
 	// Default I2C bus speed is 100 kHz.
 	if config.Frequency == 0 {
-		config.Frequency = TWI_FREQ_100KHZ
+		config.Frequency = 100 * KHz
 	}
 	if config.SDA == 0 && config.SCL == 0 {
 		config.SDA = SDA_PIN
@@ -1001,11 +1000,11 @@ func (i2s I2S) Configure(config I2SConfig) {
 	}
 
 	// configure pin for clock
-	config.SCK.Configure(PinConfig{Mode: PinCom})
+	config.SCK.Configure(PinConfig{Mode: pinCom})
 
 	// configure pin for WS, if needed
 	if config.WS != NoPin {
-		config.WS.Configure(PinConfig{Mode: PinCom})
+		config.WS.Configure(PinConfig{Mode: pinCom})
 	}
 
 	// now set serializer data size.
@@ -1044,7 +1043,7 @@ func (i2s I2S) Configure(config I2SConfig) {
 	}
 
 	// configure data pin
-	config.SD.Configure(PinConfig{Mode: PinCom})
+	config.SD.Configure(PinConfig{Mode: pinCom})
 
 	// re-enable
 	i2s.Bus.CTRLA.SetBits(sam.I2S_CTRLA_ENABLE)
@@ -1274,10 +1273,6 @@ func (spi SPI) Transfer(w byte) (byte, error) {
 	return byte(spi.Bus.DATA.Get()), nil
 }
 
-var (
-	ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
-)
-
 // 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.
 // The Tx method knows about this, and offers a few different ways of calling it.
@@ -1641,12 +1636,12 @@ func findPinTimerMapping(timer uint8, pin Pin) (PinMode, uint8) {
 	if mapping&0x07 == timer+1 {
 		// PWM output is on peripheral function E.
 		evenChannel := ((mapping >> 3) & 1) * 2
-		return PinTCC, evenChannel + uint8(pin&1)
+		return pinTCC, evenChannel + uint8(pin&1)
 	}
 	if (mapping&0x70)>>4 == timer+1 {
 		// PWM output is on peripheral function F.
 		evenChannel := ((mapping >> 7) & 1) * 2
-		return PinTCCAlt, evenChannel + uint8(pin&1)
+		return pinTCCAlt, evenChannel + uint8(pin&1)
 	}
 	return 0, 0
 }
@@ -1740,7 +1735,7 @@ func EnterBootloader() {
 
 	// Perform magic reset into bootloader, as mentioned in
 	// https://github.com/arduino/ArduinoCore-samd/issues/197
-	*(*uint32)(unsafe.Pointer(uintptr(0x20007FFC))) = RESET_MAGIC_VALUE
+	*(*uint32)(unsafe.Pointer(uintptr(0x20007FFC))) = resetMagicValue
 
 	arm.SystemReset()
 }

src/machine/machine_atsamd21_usb.go

@@ -37,8 +37,8 @@ func (dev *USBDevice) Configure(config UARTConfig) {
 	sam.USB_DEVICE.DESCADD.Set(uint32(uintptr(unsafe.Pointer(&usbEndpointDescriptors))))
 
 	// configure pins
-	USBCDC_DM_PIN.Configure(PinConfig{Mode: PinCom})
+	USBCDC_DM_PIN.Configure(PinConfig{Mode: pinCom})
-	USBCDC_DP_PIN.Configure(PinConfig{Mode: PinCom})
+	USBCDC_DP_PIN.Configure(PinConfig{Mode: pinCom})
 
 	// performs pad calibration from store fuses
 	handlePadCalibration()

src/machine/machine_atsamd21e18.go

@@ -86,53 +86,53 @@ func (p Pin) Configure(config PinConfig) {
 		sam.PORT.OUTSET0.Set(1 << uint8(p))
 		p.setPinCfg(sam.PORT_PINCFG0_INEN | sam.PORT_PINCFG0_PULLEN)
 
-	case PinSERCOM:
+	case pinSERCOM:
 		if uint8(p)&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
-			p.setPMux(val | (uint8(PinSERCOM) << sam.PORT_PMUX0_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinSERCOM) << sam.PORT_PMUX0_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
-			p.setPMux(val | (uint8(PinSERCOM) << sam.PORT_PMUX0_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinSERCOM) << sam.PORT_PMUX0_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_PINCFG0_PMUXEN | sam.PORT_PINCFG0_DRVSTR | sam.PORT_PINCFG0_INEN)
 
-	case PinSERCOMAlt:
+	case pinSERCOMAlt:
 		if uint8(p)&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
-			p.setPMux(val | (uint8(PinSERCOMAlt) << sam.PORT_PMUX0_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinSERCOMAlt) << sam.PORT_PMUX0_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
-			p.setPMux(val | (uint8(PinSERCOMAlt) << sam.PORT_PMUX0_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinSERCOMAlt) << sam.PORT_PMUX0_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_PINCFG0_PMUXEN | sam.PORT_PINCFG0_DRVSTR)
 
-	case PinCom:
+	case pinCom:
 		if uint8(p)&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
-			p.setPMux(val | (uint8(PinCom) << sam.PORT_PMUX0_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinCom) << sam.PORT_PMUX0_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
-			p.setPMux(val | (uint8(PinCom) << sam.PORT_PMUX0_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinCom) << sam.PORT_PMUX0_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_PINCFG0_PMUXEN)
-	case PinAnalog:
+	case pinAnalog:
 		if uint8(p)&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
-			p.setPMux(val | (uint8(PinAnalog) << sam.PORT_PMUX0_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinAnalog) << sam.PORT_PMUX0_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
-			p.setPMux(val | (uint8(PinAnalog) << sam.PORT_PMUX0_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinAnalog) << sam.PORT_PMUX0_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_PINCFG0_PMUXEN | sam.PORT_PINCFG0_DRVSTR)

src/machine/machine_atsamd21g18.go

@@ -137,53 +137,53 @@ func (p Pin) Configure(config PinConfig) {
 			p.setPinCfg(sam.PORT_PINCFG0_INEN | sam.PORT_PINCFG0_PULLEN)
 		}
 
-	case PinSERCOM:
+	case pinSERCOM:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
-			p.setPMux(val | (uint8(PinSERCOM) << sam.PORT_PMUX0_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinSERCOM) << sam.PORT_PMUX0_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
-			p.setPMux(val | (uint8(PinSERCOM) << sam.PORT_PMUX0_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinSERCOM) << sam.PORT_PMUX0_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_PINCFG0_PMUXEN | sam.PORT_PINCFG0_DRVSTR | sam.PORT_PINCFG0_INEN)
 
-	case PinSERCOMAlt:
+	case pinSERCOMAlt:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
-			p.setPMux(val | (uint8(PinSERCOMAlt) << sam.PORT_PMUX0_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinSERCOMAlt) << sam.PORT_PMUX0_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
-			p.setPMux(val | (uint8(PinSERCOMAlt) << sam.PORT_PMUX0_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinSERCOMAlt) << sam.PORT_PMUX0_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_PINCFG0_PMUXEN | sam.PORT_PINCFG0_DRVSTR)
 
-	case PinCom:
+	case pinCom:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
-			p.setPMux(val | (uint8(PinCom) << sam.PORT_PMUX0_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinCom) << sam.PORT_PMUX0_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
-			p.setPMux(val | (uint8(PinCom) << sam.PORT_PMUX0_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinCom) << sam.PORT_PMUX0_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_PINCFG0_PMUXEN)
-	case PinAnalog:
+	case pinAnalog:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
-			p.setPMux(val | (uint8(PinAnalog) << sam.PORT_PMUX0_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinAnalog) << sam.PORT_PMUX0_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
-			p.setPMux(val | (uint8(PinAnalog) << sam.PORT_PMUX0_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinAnalog) << sam.PORT_PMUX0_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_PINCFG0_PMUXEN | sam.PORT_PINCFG0_DRVSTR)

src/machine/machine_atsamd51.go

@@ -10,7 +10,6 @@ package machine
 import (
 	"device/arm"
 	"device/sam"
-	"errors"
 	"runtime/interrupt"
 	"unsafe"
 )
@@ -22,30 +21,29 @@ func CPUFrequency() uint32 {
 }
 
 const (
-	PinAnalog        PinMode = 1
-	PinSERCOM        PinMode = 2
-	PinSERCOMAlt     PinMode = 3
-	PinTimer         PinMode = 4
-	PinTimerAlt      PinMode = 5
-	PinTCCPDEC       PinMode = 6
-	PinCom           PinMode = 7
-	PinSDHC          PinMode = 8
-	PinI2S           PinMode = 9
-	PinPCC           PinMode = 10
-	PinGMAC          PinMode = 11
-	PinACCLK         PinMode = 12
-	PinCCL           PinMode = 13
-	PinDigital       PinMode = 14
 	PinInput         PinMode = 15
 	PinInputPullup   PinMode = 16
 	PinOutput        PinMode = 17
-	PinTCCE          PinMode = PinTimer
-	PinTCCF          PinMode = PinTimerAlt
-	PinTCCG          PinMode = PinTCCPDEC
 	PinInputPulldown PinMode = 18
-	PinCAN           PinMode = 19
+
-	PinCAN0          PinMode = PinSDHC
+	// internal pin modes
-	PinCAN1          PinMode = PinCom
+	pinAnalog    PinMode = 1
+	pinSERCOM    PinMode = 2
+	pinSERCOMAlt PinMode = 3
+	pinTCCE      PinMode = 4
+	pinTCCF      PinMode = 5
+	pinTCCG      PinMode = 6
+	pinCom       PinMode = 7
+	pinSDHC      PinMode = 8
+	pinI2S       PinMode = 9
+	pinPCC       PinMode = 10
+	pinGMAC      PinMode = 11
+	pinACCLK     PinMode = 12
+	pinCCL       PinMode = 13
+	pinDigital   PinMode = 14
+	pinCAN       PinMode = 19
+	pinCAN0      PinMode = pinSDHC
+	pinCAN1      PinMode = pinCom
 )
 
 type PinChange uint8
@@ -78,86 +76,86 @@ const (
 	PA05 Pin = 5
 	PA06 Pin = 6
 	PA07 Pin = 7
-	PA08 Pin = 8
+	PA08 Pin = 8  // peripherals: TCC0 channel 0, TCC1 channel 4
-	PA09 Pin = 9
+	PA09 Pin = 9  // peripherals: TCC0 channel 1, TCC1 channel 5
-	PA10 Pin = 10
+	PA10 Pin = 10 // peripherals: TCC0 channel 2, TCC1 channel 6
-	PA11 Pin = 11
+	PA11 Pin = 11 // peripherals: TCC0 channel 3, TCC1 channel 7
-	PA12 Pin = 12
+	PA12 Pin = 12 // peripherals: TCC0 channel 6, TCC1 channel 2
-	PA13 Pin = 13
+	PA13 Pin = 13 // peripherals: TCC0 channel 7, TCC1 channel 3
-	PA14 Pin = 14
+	PA14 Pin = 14 // peripherals: TCC2 channel 0, TCC1 channel 2
-	PA15 Pin = 15
+	PA15 Pin = 15 // peripherals: TCC2 channel 1, TCC1 channel 3
-	PA16 Pin = 16
+	PA16 Pin = 16 // peripherals: TCC1 channel 0, TCC0 channel 4
-	PA17 Pin = 17
+	PA17 Pin = 17 // peripherals: TCC1 channel 1, TCC0 channel 5
-	PA18 Pin = 18
+	PA18 Pin = 18 // peripherals: TCC1 channel 2, TCC0 channel 6
-	PA19 Pin = 19
+	PA19 Pin = 19 // peripherals: TCC1 channel 3, TCC0 channel 7
-	PA20 Pin = 20
+	PA20 Pin = 20 // peripherals: TCC1 channel 4, TCC0 channel 0
-	PA21 Pin = 21
+	PA21 Pin = 21 // peripherals: TCC1 channel 5, TCC0 channel 1
-	PA22 Pin = 22
+	PA22 Pin = 22 // peripherals: TCC1 channel 6, TCC0 channel 2
-	PA23 Pin = 23
+	PA23 Pin = 23 // peripherals: TCC1 channel 7, TCC0 channel 3
-	PA24 Pin = 24
+	PA24 Pin = 24 // peripherals: TCC2 channel 2
-	PA25 Pin = 25
+	PA25 Pin = 25 // peripherals: TCC2 channel 3
 	PA26 Pin = 26
 	PA27 Pin = 27
 	PA28 Pin = 28
 	PA29 Pin = 29
-	PA30 Pin = 30
+	PA30 Pin = 30 // peripherals: TCC2 channel 0
-	PA31 Pin = 31
+	PA31 Pin = 31 // peripherals: TCC2 channel 1
 	PB00 Pin = 32
 	PB01 Pin = 33
-	PB02 Pin = 34
+	PB02 Pin = 34 // peripherals: TCC2 channel 2
-	PB03 Pin = 35
+	PB03 Pin = 35 // peripherals: TCC2 channel 3
 	PB04 Pin = 36
 	PB05 Pin = 37
 	PB06 Pin = 38
 	PB07 Pin = 39
 	PB08 Pin = 40
 	PB09 Pin = 41
-	PB10 Pin = 42
+	PB10 Pin = 42 // peripherals: TCC0 channel 4, TCC1 channel 0
-	PB11 Pin = 43
+	PB11 Pin = 43 // peripherals: TCC0 channel 5, TCC1 channel 1
-	PB12 Pin = 44
+	PB12 Pin = 44 // peripherals: TCC3 channel 0, TCC0 channel 0
-	PB13 Pin = 45
+	PB13 Pin = 45 // peripherals: TCC3 channel 1, TCC0 channel 1
-	PB14 Pin = 46
+	PB14 Pin = 46 // peripherals: TCC4 channel 0, TCC0 channel 2
-	PB15 Pin = 47
+	PB15 Pin = 47 // peripherals: TCC4 channel 1, TCC0 channel 3
-	PB16 Pin = 48
+	PB16 Pin = 48 // peripherals: TCC3 channel 0, TCC0 channel 4
-	PB17 Pin = 49
+	PB17 Pin = 49 // peripherals: TCC3 channel 1, TCC0 channel 5
-	PB18 Pin = 50
+	PB18 Pin = 50 // peripherals: TCC1 channel 0
-	PB19 Pin = 51
+	PB19 Pin = 51 // peripherals: TCC1 channel 1
-	PB20 Pin = 52
+	PB20 Pin = 52 // peripherals: TCC1 channel 2
-	PB21 Pin = 53
+	PB21 Pin = 53 // peripherals: TCC1 channel 3
 	PB22 Pin = 54
 	PB23 Pin = 55
 	PB24 Pin = 56
 	PB25 Pin = 57
-	PB26 Pin = 58
+	PB26 Pin = 58 // peripherals: TCC1 channel 2
-	PB27 Pin = 59
+	PB27 Pin = 59 // peripherals: TCC1 channel 3
-	PB28 Pin = 60
+	PB28 Pin = 60 // peripherals: TCC1 channel 4
-	PB29 Pin = 61
+	PB29 Pin = 61 // peripherals: TCC1 channel 5
-	PB30 Pin = 62
+	PB30 Pin = 62 // peripherals: TCC4 channel 0, TCC0 channel 6
-	PB31 Pin = 63
+	PB31 Pin = 63 // peripherals: TCC4 channel 1, TCC0 channel 7
 	PC00 Pin = 64
 	PC01 Pin = 65
 	PC02 Pin = 66
 	PC03 Pin = 67
-	PC04 Pin = 68
+	PC04 Pin = 68 // peripherals: TCC0 channel 0
-	PC05 Pin = 69
+	PC05 Pin = 69 // peripherals: TCC0 channel 1
 	PC06 Pin = 70
 	PC07 Pin = 71
 	PC08 Pin = 72
 	PC09 Pin = 73
-	PC10 Pin = 74
+	PC10 Pin = 74 // peripherals: TCC0 channel 0, TCC1 channel 4
-	PC11 Pin = 75
+	PC11 Pin = 75 // peripherals: TCC0 channel 1, TCC1 channel 5
-	PC12 Pin = 76
+	PC12 Pin = 76 // peripherals: TCC0 channel 2, TCC1 channel 6
-	PC13 Pin = 77
+	PC13 Pin = 77 // peripherals: TCC0 channel 3, TCC1 channel 7
-	PC14 Pin = 78
+	PC14 Pin = 78 // peripherals: TCC0 channel 4, TCC1 channel 0
-	PC15 Pin = 79
+	PC15 Pin = 79 // peripherals: TCC0 channel 5, TCC1 channel 1
-	PC16 Pin = 80
+	PC16 Pin = 80 // peripherals: TCC0 channel 0
-	PC17 Pin = 81
+	PC17 Pin = 81 // peripherals: TCC0 channel 1
-	PC18 Pin = 82
+	PC18 Pin = 82 // peripherals: TCC0 channel 2
-	PC19 Pin = 83
+	PC19 Pin = 83 // peripherals: TCC0 channel 3
-	PC20 Pin = 84
+	PC20 Pin = 84 // peripherals: TCC0 channel 4
-	PC21 Pin = 85
+	PC21 Pin = 85 // peripherals: TCC0 channel 5
-	PC22 Pin = 86
+	PC22 Pin = 86 // peripherals: TCC0 channel 6
-	PC23 Pin = 87
+	PC23 Pin = 87 // peripherals: TCC0 channel 7
 	PC24 Pin = 88
 	PC25 Pin = 89
 	PC26 Pin = 90
@@ -174,20 +172,20 @@ const (
 	PD05 Pin = 101
 	PD06 Pin = 102
 	PD07 Pin = 103
-	PD08 Pin = 104
+	PD08 Pin = 104 // peripherals: TCC0 channel 1
-	PD09 Pin = 105
+	PD09 Pin = 105 // peripherals: TCC0 channel 2
-	PD10 Pin = 106
+	PD10 Pin = 106 // peripherals: TCC0 channel 3
-	PD11 Pin = 107
+	PD11 Pin = 107 // peripherals: TCC0 channel 4
-	PD12 Pin = 108
+	PD12 Pin = 108 // peripherals: TCC0 channel 5
-	PD13 Pin = 109
+	PD13 Pin = 109 // peripherals: TCC0 channel 6
 	PD14 Pin = 110
 	PD15 Pin = 111
 	PD16 Pin = 112
 	PD17 Pin = 113
 	PD18 Pin = 114
 	PD19 Pin = 115
-	PD20 Pin = 116
+	PD20 Pin = 116 // peripherals: TCC1 channel 0
-	PD21 Pin = 117
+	PD21 Pin = 117 // peripherals: TCC1 channel 1
 	PD22 Pin = 118
 	PD23 Pin = 119
 	PD24 Pin = 120
@@ -339,7 +337,7 @@ func findPinPadMapping(sercom uint8, pin Pin) (pinMode PinMode, pad uint32, ok b
 	if upper != 0 {
 		// SERCOM
 		if (upper>>4)-1 == sercom {
-			pinMode = PinSERCOM
+			pinMode = pinSERCOM
 			pad |= uint32(upper % 4)
 			ok = true
 		}
@@ -347,7 +345,7 @@ func findPinPadMapping(sercom uint8, pin Pin) (pinMode PinMode, pad uint32, ok b
 	if lower != 0 {
 		// SERCOM-ALT
 		if (lower>>4)-1 == sercom {
-			pinMode = PinSERCOMAlt
+			pinMode = pinSERCOMAlt
 			pad |= uint32(lower % 4)
 			ok = true
 		}
@@ -581,65 +579,65 @@ func (p Pin) Configure(config PinConfig) {
 		sam.PORT.GROUP[group].OUTSET.Set(1 << pin_in_group)
 		p.setPinCfg(sam.PORT_GROUP_PINCFG_INEN | sam.PORT_GROUP_PINCFG_PULLEN)
 
-	case PinSERCOM:
+	case pinSERCOM:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
-			p.setPMux(val | (uint8(PinSERCOM) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinSERCOM) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
-			p.setPMux(val | (uint8(PinSERCOM) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinSERCOM) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN | sam.PORT_GROUP_PINCFG_DRVSTR | sam.PORT_GROUP_PINCFG_INEN)
 
-	case PinSERCOMAlt:
+	case pinSERCOMAlt:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
-			p.setPMux(val | (uint8(PinSERCOMAlt) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinSERCOMAlt) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
-			p.setPMux(val | (uint8(PinSERCOMAlt) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinSERCOMAlt) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN | sam.PORT_GROUP_PINCFG_DRVSTR)
 
-	case PinCom:
+	case pinCom:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
-			p.setPMux(val | (uint8(PinCom) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinCom) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
-			p.setPMux(val | (uint8(PinCom) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinCom) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN)
-	case PinAnalog:
+	case pinAnalog:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
-			p.setPMux(val | (uint8(PinAnalog) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinAnalog) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
-			p.setPMux(val | (uint8(PinAnalog) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinAnalog) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN | sam.PORT_GROUP_PINCFG_DRVSTR)
-	case PinSDHC:
+	case pinSDHC:
 		if p&1 > 0 {
 			// odd pin, so save the even pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
-			p.setPMux(val | (uint8(PinSDHC) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
+			p.setPMux(val | (uint8(pinSDHC) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
 		} else {
 			// even pin, so save the odd pins
 			val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
-			p.setPMux(val | (uint8(PinSDHC) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
+			p.setPMux(val | (uint8(pinSDHC) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
 		}
 		// enable port config
 		p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN)
@@ -815,7 +813,7 @@ func (a ADC) Configure(config ADCConfig) {
 		adc.REFCTRL.SetBits(sam.ADC_REFCTRL_REFSEL_INTVCC1)
 	}
 
-	a.Pin.Configure(PinConfig{Mode: PinAnalog})
+	a.Pin.Configure(PinConfig{Mode: pinAnalog})
 }
 
 // Get returns the current value of a ADC pin, in the range 0..0xffff.
@@ -1151,7 +1149,7 @@ const i2cTimeout = 1000
 func (i2c *I2C) Configure(config I2CConfig) error {
 	// Default I2C bus speed is 100 kHz.
 	if config.Frequency == 0 {
-		config.Frequency = TWI_FREQ_100KHZ
+		config.Frequency = 100 * KHz
 	}
 
 	// Use default I2C pins if not set.
@@ -1527,10 +1525,6 @@ func (spi SPI) Transfer(w byte) (byte, error) {
 	return byte(spi.Bus.DATA.Get()), nil
 }
 
-var (
-	ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
-)
-
 // 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.
 // The Tx method knows about this, and offers a few different ways of calling it.
@@ -1872,7 +1866,7 @@ var pinTimerMapping = [...]struct{ F, G uint8 }{
 	PB02 / 2: {pinTCC2_2, 0},
 }
 
-// findPinPadMapping returns the pin mode (PinTCCF or PinTCCG) and the channel
+// findPinPadMapping returns the pin mode (pinTCCF or pinTCCG) and the channel
 // number for a given timer and pin. A zero PinMode is returned if no mapping
 // could be found.
 func findPinTimerMapping(timer uint8, pin Pin) (PinMode, uint8) {
@@ -1884,12 +1878,12 @@ func findPinTimerMapping(timer uint8, pin Pin) (PinMode, uint8) {
 
 	// Check for column F in the datasheet.
 	if mapping.F>>4-1 == timer {
-		return PinTCCF, mapping.F&0x0f + uint8(pin)&1
+		return pinTCCF, mapping.F&0x0f + uint8(pin)&1
 	}
 
 	// Check for column G in the datasheet.
 	if mapping.G>>4-1 == timer {
-		return PinTCCG, mapping.G&0x0f + uint8(pin)&1
+		return pinTCCG, mapping.G&0x0f + uint8(pin)&1
 	}
 
 	// Nothing found.
@@ -1980,7 +1974,7 @@ func EnterBootloader() {
 
 	// Perform magic reset into bootloader, as mentioned in
 	// https://github.com/arduino/ArduinoCore-samd/issues/197
-	*(*uint32)(unsafe.Pointer(uintptr(0x20000000 + HSRAM_SIZE - 4))) = RESET_MAGIC_VALUE
+	*(*uint32)(unsafe.Pointer(uintptr(0x20000000 + HSRAM_SIZE - 4))) = resetMagicValue
 
 	arm.SystemReset()
 }

src/machine/machine_atsamd51_usb.go

@@ -37,8 +37,8 @@ func (dev *USBDevice) Configure(config UARTConfig) {
 	sam.USB_DEVICE.DESCADD.Set(uint32(uintptr(unsafe.Pointer(&usbEndpointDescriptors))))
 
 	// configure pins
-	USBCDC_DM_PIN.Configure(PinConfig{Mode: PinCom})
+	USBCDC_DM_PIN.Configure(PinConfig{Mode: pinCom})
-	USBCDC_DP_PIN.Configure(PinConfig{Mode: PinCom})
+	USBCDC_DP_PIN.Configure(PinConfig{Mode: pinCom})
 
 	// performs pad calibration from store fuses
 	handlePadCalibration()

src/machine/machine_atsame5x_can.go

@@ -68,9 +68,9 @@ func (can *CAN) Configure(config CANConfig) error {
 		config.Standby.Low()
 	}
 
-	mode := PinCAN0
+	mode := pinCAN0
 	if can.instance() == 1 {
-		mode = PinCAN1
+		mode = pinCAN1
 	}
 
 	config.Rx.Configure(PinConfig{Mode: mode})

src/machine/machine_esp32c3.go

@@ -59,12 +59,9 @@ type PinChange uint8
 
 // Pin change interrupt constants for SetInterrupt.
 const (
-	PinNoInterrupt PinChange = iota
+	PinRising PinChange = iota + 1
-	PinRising
 	PinFalling
 	PinToggle
-	PinLowLevel
-	PinHighLevel
 )
 
 // Configure this pin with the given configuration.
@@ -190,7 +187,7 @@ func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) (err error) {
 		return ErrInvalidInputPin
 	}
 
-	if callback == nil || change == PinNoInterrupt {
+	if callback == nil {
 		// Disable this pin interrupt
 		p.pin().ClearBits(esp.GPIO_PIN_PIN_INT_TYPE_Msk | esp.GPIO_PIN_PIN_INT_ENA_Msk)
 
@@ -264,15 +261,6 @@ type UART struct {
 	DataOverflowDetected bool // set when data overflow detected in UART FIFO buffer or RingBuffer
 }
 
-type UARTStopBits int
-
-const (
-	UARTStopBits_Default UARTStopBits = iota
-	UARTStopBits_1
-	UARTStopBits_1_5
-	UARTStopBits_2
-)
-
 const (
 	defaultDataBits = 8
 	defaultStopBit  = 1

src/machine/machine_fe310.go

@@ -18,9 +18,11 @@ func CPUFrequency() uint32 {
 const (
 	PinInput PinMode = iota
 	PinOutput
-	PinPWM
+
-	PinSPI
+	// internal pin modes
-	PinI2C = PinSPI
+	pinPWM
+	pinSPI
+	pinI2C = pinSPI
 )
 
 // Configure this pin with the given configuration.
@@ -29,10 +31,10 @@ func (p Pin) Configure(config PinConfig) {
 	switch config.Mode {
 	case PinOutput:
 		sifive.GPIO0.OUTPUT_EN.SetBits(1 << uint8(p))
-	case PinPWM:
+	case pinPWM:
 		sifive.GPIO0.IOF_EN.SetBits(1 << uint8(p))
 		sifive.GPIO0.IOF_SEL.SetBits(1 << uint8(p))
-	case PinSPI:
+	case pinSPI:
 		sifive.GPIO0.IOF_EN.SetBits(1 << uint8(p))
 		sifive.GPIO0.IOF_SEL.ClearBits(1 << uint8(p))
 	}
@@ -145,9 +147,9 @@ func (spi SPI) Configure(config SPIConfig) error {
 	}
 
 	// enable pins for SPI
-	config.SCK.Configure(PinConfig{Mode: PinSPI})
+	config.SCK.Configure(PinConfig{Mode: pinSPI})
-	config.SDO.Configure(PinConfig{Mode: PinSPI})
+	config.SDO.Configure(PinConfig{Mode: pinSPI})
-	config.SDI.Configure(PinConfig{Mode: PinSPI})
+	config.SDI.Configure(PinConfig{Mode: pinSPI})
 
 	// set default frequency
 	if config.Frequency == 0 {
@@ -231,7 +233,7 @@ type I2CConfig struct {
 func (i2c *I2C) Configure(config I2CConfig) error {
 	var i2cClockFrequency uint32 = 32000000
 	if config.Frequency == 0 {
-		config.Frequency = TWI_FREQ_100KHZ
+		config.Frequency = 100 * KHz
 	}
 
 	if config.SDA == 0 && config.SCL == 0 {
@@ -251,8 +253,8 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 	// enable controller
 	i2c.Bus.CTR.SetBits(sifive.I2C_CTR_EN)
 
-	config.SDA.Configure(PinConfig{Mode: PinI2C})
+	config.SDA.Configure(PinConfig{Mode: pinI2C})
-	config.SCL.Configure(PinConfig{Mode: PinI2C})
+	config.SCL.Configure(PinConfig{Mode: pinI2C})
 
 	return nil
 }

src/machine/machine_k210.go

@@ -23,11 +23,17 @@ type PinChange uint8
 // Pin modes.
 const (
 	PinInput PinMode = iota
-	PinInputPullUp
+	PinInputPullup
-	PinInputPullDown
+	PinInputPulldown
 	PinOutput
 )
 
+// Deprecated: use PinInputPullup and PinInputPulldown instead.
+const (
+	PinInputPullUp   = PinInputPullup
+	PinInputPullDown = PinInputPulldown
+)
+
 // FPIOA internal pull resistors.
 const (
 	fpioaPullNone fpioaPullMode = iota
@@ -89,10 +95,10 @@ func (p Pin) Configure(config PinConfig) {
 	case PinInput:
 		p.setFPIOAIOPull(fpioaPullNone)
 		input = true
-	case PinInputPullUp:
+	case PinInputPullup:
 		p.setFPIOAIOPull(fpioaPullUp)
 		input = true
-	case PinInputPullDown:
+	case PinInputPulldown:
 		p.setFPIOAIOPull(fpioaPullDown)
 		input = true
 	case PinOutput:
@@ -517,7 +523,7 @@ type I2CConfig struct {
 func (i2c *I2C) Configure(config I2CConfig) error {
 
 	if config.Frequency == 0 {
-		config.Frequency = TWI_FREQ_100KHZ
+		config.Frequency = 100 * KHz
 	}
 
 	if config.SDA == 0 && config.SCL == 0 {

src/machine/machine_mimxrt1062.go

@@ -21,36 +21,40 @@ func CPUFrequency() uint32 {
 const (
 	// GPIO
 	PinInput PinMode = iota
-	PinInputPullUp
+	PinInputPullup
-	PinInputPullDown
+	PinInputPulldown
 	PinOutput
 	PinOutputOpenDrain
 	PinDisable
 
 	// ADC
-	PinInputAnalog
+	pinInputAnalog
 
 	// UART
-	PinModeUARTTX
+	pinModeUARTTX
-	PinModeUARTRX
+	pinModeUARTRX
 
 	// SPI
-	PinModeSPISDI
+	pinModeSPISDI
-	PinModeSPISDO
+	pinModeSPISDO
-	PinModeSPICLK
+	pinModeSPICLK
-	PinModeSPICS
+	pinModeSPICS
 
 	// I2C
-	PinModeI2CSDA
+	pinModeI2CSDA
-	PinModeI2CSCL
+	pinModeI2CSCL
+)
+
+// Deprecated: use PinInputPullup and PinInputPulldown instead.
+const (
+	PinInputPullUp   = PinInputPullup
+	PinInputPullDown = PinInputPulldown
 )
 
 type PinChange uint8
 
 const (
-	PinLow PinChange = iota
+	PinRising PinChange = iota + 2
-	PinHigh
-	PinRising
 	PinFalling
 	PinToggle
 )
@@ -259,11 +263,11 @@ func (p Pin) Configure(config PinConfig) {
 		gpio.GDIR.ClearBits(p.getMask())
 		pad.Set(dse(7))
 
-	case PinInputPullUp:
+	case PinInputPullup:
 		gpio.GDIR.ClearBits(p.getMask())
 		pad.Set(dse(7) | pke | pue | pup(3) | hys)
 
-	case PinInputPullDown:
+	case PinInputPulldown:
 		gpio.GDIR.ClearBits(p.getMask())
 		pad.Set(dse(7) | pke | pue | hys)
 
@@ -279,29 +283,29 @@ func (p Pin) Configure(config PinConfig) {
 		gpio.GDIR.ClearBits(p.getMask())
 		pad.Set(dse(7) | hys)
 
-	case PinInputAnalog:
+	case pinInputAnalog:
 		gpio.GDIR.ClearBits(p.getMask())
 		pad.Set(dse(7))
 
-	case PinModeUARTTX:
+	case pinModeUARTTX:
 		pad.Set(sre | dse(3) | spd(3))
 
-	case PinModeUARTRX:
+	case pinModeUARTRX:
 		pad.Set(dse(7) | pke | pue | pup(3) | hys)
 
-	case PinModeSPISDI:
+	case pinModeSPISDI:
 		pad.Set(dse(7) | spd(2))
 
-	case PinModeSPISDO:
+	case pinModeSPISDO:
 		pad.Set(dse(7) | spd(2))
 
-	case PinModeSPICLK:
+	case pinModeSPICLK:
 		pad.Set(dse(7) | spd(2))
 
-	case PinModeSPICS:
+	case pinModeSPICS:
 		pad.Set(dse(7))
 
-	case PinModeI2CSDA, PinModeI2CSCL:
+	case pinModeI2CSDA, pinModeI2CSCL:
 		pad.Set(ode | sre | dse(4) | spd(1) | pke | pue | pup(3))
 	}
 
@@ -387,7 +391,7 @@ func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) error {
 	mask := p.getMask()
 	if nil != callback {
 		switch change {
-		case PinLow, PinHigh, PinRising, PinFalling:
+		case PinRising, PinFalling:
 			gpio.EDGE_SEL.ClearBits(mask)
 			var reg *volatile.Register32
 			var pos uint8
@@ -746,7 +750,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 	switch config.Mode {
 
 	// GPIO
-	case PinInput, PinInputPullUp, PinInputPullDown,
+	case PinInput, PinInputPullup, PinInputPulldown,
 		PinOutput, PinOutputOpenDrain, PinDisable:
 		mode := uint32(0x5) // GPIO is always alternate function 5
 		if forcePath {
@@ -755,7 +759,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 		return mode
 
 	// ADC
-	case PinInputAnalog:
+	case pinInputAnalog:
 		mode := uint32(0x5) // use alternate function 5 (GPIO)
 		if forcePath {
 			mode |= 0x10 // SION bit
@@ -763,7 +767,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 		return mode
 
 	// UART RX/TX
-	case PinModeUARTRX, PinModeUARTTX:
+	case pinModeUARTRX, pinModeUARTTX:
 		mode := uint32(0x2) // UART is usually alternate function 2 on Teensy 4.x
 		// Teensy 4.1 has a UART (LPUART5) with alternate function 1
 		if p == PB28 || p == PB29 {
@@ -772,7 +776,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 		return mode
 
 	// SPI SDI
-	case PinModeSPISDI:
+	case pinModeSPISDI:
 		var mode uint32
 		switch p {
 		case PC15: // LPSPI1 SDI on PC15 alternate function 4
@@ -790,7 +794,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 		return mode
 
 	// SPI SDO
-	case PinModeSPISDO:
+	case pinModeSPISDO:
 		var mode uint32
 		switch p {
 		case PC14: // LPSPI1 SDO on PC14 alternate function 4
@@ -808,7 +812,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 		return mode
 
 	// SPI SCK
-	case PinModeSPICLK:
+	case pinModeSPICLK:
 		var mode uint32
 		switch p {
 		case PC12: // LPSPI1 SCK on PC12 alternate function 4
@@ -826,7 +830,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 		return mode
 
 	// SPI CS
-	case PinModeSPICS:
+	case pinModeSPICS:
 		var mode uint32
 		switch p {
 		case PC13: // LPSPI1 CS on PC13 alternate function 4
@@ -844,7 +848,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 		return mode
 
 	// I2C SDA
-	case PinModeI2CSDA:
+	case pinModeI2CSDA:
 		var mode uint32
 		switch p {
 		case PA13: // LPI2C4 SDA on PA13 alternate function 0
@@ -862,7 +866,7 @@ func (p Pin) getMuxMode(config PinConfig) uint32 {
 		return mode
 
 	// I2C SCL
-	case PinModeI2CSCL:
+	case pinModeI2CSCL:
 		var mode uint32
 		switch p {
 		case PA12: // LPI2C4 SCL on PA12 alternate function 0
@@ -898,7 +902,7 @@ func (a ADC) Configure(config ADCConfig) {
 		defaultSamples    = uint32(4)
 	)
 
-	a.Pin.Configure(PinConfig{Mode: PinInputAnalog})
+	a.Pin.Configure(PinConfig{Mode: pinInputAnalog})
 
 	resolution, samples := config.Resolution, config.Samples
 	if 0 == resolution {

src/machine/machine_mimxrt1062_i2c.go

@@ -10,15 +10,6 @@ import (
 	"errors"
 )
 
-const (
-	TWI_FREQ_BUS     = 24000000        // LPI2C root clock is on 24 MHz OSC
-	TWI_FREQ_100KHZ  = 100000          // StandardMode (100 kHz)
-	TWI_FREQ_400KHZ  = 400000          // FastMode (400 kHz)
-	TWI_FREQ_1MHZ    = 1000000         // FastModePlus (1 MHz)
-	TWI_FREQ_5MHZ    = 5000000         // UltraFastMode (5 MHz)
-	TWI_FREQ_DEFAULT = TWI_FREQ_100KHZ // default to StandardMode (100 kHz)
-)
-
 var (
 	errI2CWriteTimeout       = errors.New("I2C timeout during write")
 	errI2CReadTimeout        = errors.New("I2C timeout during read")
@@ -165,8 +156,8 @@ func (i2c *I2C) Configure(config I2CConfig) {
 	sda, scl := i2c.setPins(config)
 
 	// configure the mux and pad control registers
-	sda.Configure(PinConfig{Mode: PinModeI2CSDA})
+	sda.Configure(PinConfig{Mode: pinModeI2CSDA})
-	scl.Configure(PinConfig{Mode: PinModeI2CSCL})
+	scl.Configure(PinConfig{Mode: pinModeI2CSCL})
 
 	// configure the mux input selector
 	i2c.muxSDA.connect()
@@ -174,7 +165,7 @@ func (i2c *I2C) Configure(config I2CConfig) {
 
 	freq := config.Frequency
 	if 0 == freq {
-		freq = TWI_FREQ_DEFAULT
+		freq = 100 * KHz
 	}
 
 	// reset clock and registers, and enable LPI2C module interface
@@ -305,7 +296,7 @@ func (i2c *I2C) setFrequency(freq uint32) {
 	wasEnabled := i2c.Bus.MCR.HasBits(nxp.LPI2C_MCR_MEN)
 	i2c.Bus.MCR.ClearBits(nxp.LPI2C_MCR_MEN)
 
-	// baud rate = (TWI_FREQ_BUS/(2^pre))/(CLKLO+1 + CLKHI+1 + FLOOR((2+FILTSCL)/(2^pre)))
+	// baud rate = (24MHz/(2^pre))/(CLKLO+1 + CLKHI+1 + FLOOR((2+FILTSCL)/(2^pre)))
 	// assume: CLKLO=2*CLKHI, SETHOLD=CLKHI, DATAVD=CLKHI/2
 	for pre := uint32(1); pre <= 128; pre *= 2 {
 		if bestError == 0 {
@@ -314,9 +305,9 @@ func (i2c *I2C) setFrequency(freq uint32) {
 		for clkHi := uint32(1); clkHi < 32; clkHi++ {
 			var absError, rate uint32
 			if clkHi == 1 {
-				rate = (TWI_FREQ_BUS / pre) / (1 + 3 + 2 + 2/pre)
+				rate = (24 * MHz / pre) / (1 + 3 + 2 + 2/pre)
 			} else {
-				rate = (TWI_FREQ_BUS / pre) / (3*clkHi + 2 + 2/pre)
+				rate = (24 * MHz / pre) / (3*clkHi + 2 + 2/pre)
 			}
 			if freq > rate {
 				absError = freq - rate
@@ -370,15 +361,15 @@ func (i2c *I2C) setFrequency(freq uint32) {
 		mcfgr2, mcfgr3 uint32
 	)
 	const i2cClockStretchTimeout = 15000 // microseconds
-	if freq >= TWI_FREQ_5MHZ {
+	if freq >= 5*MHz {
 		// I2C UltraFastMode 5 MHz
 		mcfgr2 = 0 // disable glitch filters and timeout for UltraFastMode
 		mcfgr3 = 0 //
-	} else if freq >= TWI_FREQ_1MHZ {
+	} else if freq >= 1*MHz {
 		// I2C FastModePlus 1 MHz
 		mcfgr2 = filtsda(1) | filtscl(1) | busidle(2400) // 100us timeout
 		mcfgr3 = pinlow(i2cClockStretchTimeout*24/256 + 1)
-	} else if freq >= TWI_FREQ_400KHZ {
+	} else if freq >= 400*KHz {
 		// I2C FastMode 400 kHz
 		mcfgr2 = filtsda(2) | filtscl(2) | busidle(3600) // 150us timeout
 		mcfgr3 = pinlow(i2cClockStretchTimeout*24/256 + 1)

src/machine/machine_mimxrt1062_spi.go

@@ -77,10 +77,10 @@ func (spi *SPI) Configure(config SPIConfig) {
 	spi.sdi, spi.sdo, spi.sck, spi.cs = config.getPins()
 
 	// configure the mux and pad control registers
-	spi.sdi.Configure(PinConfig{Mode: PinModeSPISDI})
+	spi.sdi.Configure(PinConfig{Mode: pinModeSPISDI})
-	spi.sdo.Configure(PinConfig{Mode: PinModeSPISDO})
+	spi.sdo.Configure(PinConfig{Mode: pinModeSPISDO})
-	spi.sck.Configure(PinConfig{Mode: PinModeSPICLK})
+	spi.sck.Configure(PinConfig{Mode: pinModeSPICLK})
-	spi.cs.Configure(PinConfig{Mode: PinModeSPICS})
+	spi.cs.Configure(PinConfig{Mode: pinModeSPICS})
 
 	// configure the mux input selector
 	spi.muxSDI.connect()

src/machine/machine_mimxrt1062_uart.go

@@ -68,8 +68,8 @@ func (uart *UART) Configure(config UARTConfig) {
 	uart.tx = config.TX
 
 	// configure the mux and pad control registers
-	uart.rx.Configure(PinConfig{Mode: PinModeUARTRX})
+	uart.rx.Configure(PinConfig{Mode: pinModeUARTRX})
-	uart.tx.Configure(PinConfig{Mode: PinModeUARTTX})
+	uart.tx.Configure(PinConfig{Mode: pinModeUARTTX})
 
 	// configure the mux input selector
 	uart.muxRX.connect()
@@ -159,8 +159,8 @@ func (uart *UART) Disable() {
 		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.rx.Configure(PinConfig{Mode: PinInputPullup})
-		uart.tx.Configure(PinConfig{Mode: PinInputPullUp})
+		uart.tx.Configure(PinConfig{Mode: PinInputPullup})
 	}
 	uart.configured = false
 }

src/machine/machine_nrf.go

@@ -5,15 +5,10 @@ package machine
 
 import (
 	"device/nrf"
-	"errors"
 	"runtime/interrupt"
 	"unsafe"
 )
 
-var (
-	ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
-)
-
 const deviceName = nrf.Device
 
 const (
@@ -230,7 +225,7 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 
 	// Default I2C bus speed is 100 kHz.
 	if config.Frequency == 0 {
-		config.Frequency = TWI_FREQ_100KHZ
+		config.Frequency = 100 * KHz
 	}
 	// Default I2C pins if not set.
 	if config.SDA == 0 && config.SCL == 0 {
@@ -253,7 +248,7 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 		(nrf.GPIO_PIN_CNF_DRIVE_S0D1 << nrf.GPIO_PIN_CNF_DRIVE_Pos) |
 		(nrf.GPIO_PIN_CNF_SENSE_Disabled << nrf.GPIO_PIN_CNF_SENSE_Pos))
 
-	if config.Frequency == TWI_FREQ_400KHZ {
+	if config.Frequency >= 400*KHz {
 		i2c.Bus.FREQUENCY.Set(nrf.TWI_FREQUENCY_FREQUENCY_K400)
 	} else {
 		i2c.Bus.FREQUENCY.Set(nrf.TWI_FREQUENCY_FREQUENCY_K100)
@@ -350,3 +345,41 @@ func (i2c *I2C) readByte() (byte, error) {
 	i2c.Bus.EVENTS_RXDREADY.Set(0)
 	return byte(i2c.Bus.RXD.Get()), nil
 }
+
+var rngStarted = false
+
+// GetRNG returns 32 bits of non-deterministic random data based on internal thermal noise.
+// According to Nordic's documentation, the random output is suitable for cryptographic purposes.
+func GetRNG() (ret uint32, err error) {
+	// There's no apparent way to check the status of the RNG peripheral's task, so simply start it
+	// to avoid deadlocking while waiting for output.
+	if !rngStarted {
+		nrf.RNG.TASKS_START.Set(1)
+		nrf.RNG.SetCONFIG_DERCEN(nrf.RNG_CONFIG_DERCEN_Enabled)
+		rngStarted = true
+	}
+
+	// The RNG returns one byte at a time, so stack up four bytes into a single uint32 for return.
+	for i := 0; i < 4; i++ {
+		// Wait for data to be ready.
+		for nrf.RNG.EVENTS_VALRDY.Get() == 0 {
+		}
+		// Append random byte to output.
+		ret = (ret << 8) ^ nrf.RNG.GetVALUE()
+		// Unset the EVENTS_VALRDY register to avoid reading the same random output twice.
+		nrf.RNG.EVENTS_VALRDY.Set(0)
+	}
+
+	return ret, nil
+}
+
+// ReadTemperature reads the silicon die temperature of the chip. The return
+// value is in milli-celsius.
+func ReadTemperature() int32 {
+	nrf.TEMP.TASKS_START.Set(1)
+	for nrf.TEMP.EVENTS_DATARDY.Get() == 0 {
+	}
+	temp := int32(nrf.TEMP.TEMP.Get()) * 250 // the returned value is in units of 0.25°C
+	nrf.TEMP.EVENTS_DATARDY.Set(0)
+	return temp
+}

src/machine/machine_nrf52840_enter_bootloader.go

@@ -9,16 +9,16 @@ import (
 )
 
 const (
-	DFU_MAGIC_SERIAL_ONLY_RESET = 0x4e
+	dfuMagicSerialOnlyReset = 0x4e
-	DFU_MAGIC_UF2_RESET         = 0x57
+	dfuMagicUF2Reset        = 0x57
-	DFU_MAGIC_OTA_RESET         = 0xA8
+	dfuMagicOTAReset        = 0xA8
 )
 
 // EnterSerialBootloader resets the chip into the serial bootloader. After
 // reset, it can be flashed using serial/nrfutil.
 func EnterSerialBootloader() {
 	arm.DisableInterrupts()
-	nrf.POWER.GPREGRET.Set(DFU_MAGIC_SERIAL_ONLY_RESET)
+	nrf.POWER.GPREGRET.Set(dfuMagicSerialOnlyReset)
 	arm.SystemReset()
 }
 
@@ -26,7 +26,7 @@ func EnterSerialBootloader() {
 // can be flashed via nrfutil or by copying a UF2 file to the mass storage device
 func EnterUF2Bootloader() {
 	arm.DisableInterrupts()
-	nrf.POWER.GPREGRET.Set(DFU_MAGIC_UF2_RESET)
+	nrf.POWER.GPREGRET.Set(dfuMagicUF2Reset)
 	arm.SystemReset()
 }
 
@@ -34,6 +34,6 @@ func EnterUF2Bootloader() {
 // flashed via an OTA update
 func EnterOTABootloader() {
 	arm.DisableInterrupts()
-	nrf.POWER.GPREGRET.Set(DFU_MAGIC_OTA_RESET)
+	nrf.POWER.GPREGRET.Set(dfuMagicOTAReset)
 	arm.SystemReset()
 }

src/machine/machine_nxpmk66f18.go

@@ -42,13 +42,19 @@ const deviceName = nxp.Device
 
 const (
 	PinInput PinMode = iota
-	PinInputPullUp
+	PinInputPullup
-	PinInputPullDown
+	PinInputPulldown
 	PinOutput
 	PinOutputOpenDrain
 	PinDisable
 )
 
+// Deprecated: use PinInputPullup and PinInputPulldown instead.
+const (
+	PinInputPullUp   = PinInputPullup
+	PinInputPullDown = PinInputPulldown
+)
+
 const (
 	PA00 Pin = iota
 	PA01
@@ -223,11 +229,11 @@ func (p Pin) Configure(config PinConfig) {
 		gpio.PDDR.ClearBits(1 << pos)
 		pcr.Set((1 << nxp.PORT_PCR0_MUX_Pos))
 
-	case PinInputPullUp:
+	case PinInputPullup:
 		gpio.PDDR.ClearBits(1 << pos)
 		pcr.Set((1 << nxp.PORT_PCR0_MUX_Pos) | nxp.PORT_PCR0_PE | nxp.PORT_PCR0_PS)
 
-	case PinInputPullDown:
+	case PinInputPulldown:
 		gpio.PDDR.ClearBits(1 << pos)
 		pcr.Set((1 << nxp.PORT_PCR0_MUX_Pos) | nxp.PORT_PCR0_PE)
 

src/machine/machine_nxpmk66f18_uart.go

@@ -203,8 +203,8 @@ func (u *UART) Disable() {
 	u.C2.Set(0)
 
 	// reconfigure pin
-	u.DefaultRX.Configure(PinConfig{Mode: PinInputPullUp})
+	u.DefaultRX.Configure(PinConfig{Mode: PinInputPullup})
-	u.DefaultTX.Configure(PinConfig{Mode: PinInputPullUp})
+	u.DefaultTX.Configure(PinConfig{Mode: PinInputPullup})
 
 	// clear flags
 	u.S1.Get()

src/machine/machine_rp2040.go

@@ -11,36 +11,36 @@ const deviceName = rp.Device
 
 const (
 	// GPIO pins
-	GPIO0  Pin = 0
+	GPIO0  Pin = 0  // peripherals: PWM0 channel A
-	GPIO1  Pin = 1
+	GPIO1  Pin = 1  // peripherals: PWM0 channel B
-	GPIO2  Pin = 2
+	GPIO2  Pin = 2  // peripherals: PWM1 channel A
-	GPIO3  Pin = 3
+	GPIO3  Pin = 3  // peripherals: PWM1 channel B
-	GPIO4  Pin = 4
+	GPIO4  Pin = 4  // peripherals: PWM2 channel A
-	GPIO5  Pin = 5
+	GPIO5  Pin = 5  // peripherals: PWM2 channel B
-	GPIO6  Pin = 6
+	GPIO6  Pin = 6  // peripherals: PWM3 channel A
-	GPIO7  Pin = 7
+	GPIO7  Pin = 7  // peripherals: PWM3 channel B
-	GPIO8  Pin = 8
+	GPIO8  Pin = 8  // peripherals: PWM4 channel A
-	GPIO9  Pin = 9
+	GPIO9  Pin = 9  // peripherals: PWM4 channel B
-	GPIO10 Pin = 10
+	GPIO10 Pin = 10 // peripherals: PWM5 channel A
-	GPIO11 Pin = 11
+	GPIO11 Pin = 11 // peripherals: PWM5 channel B
-	GPIO12 Pin = 12
+	GPIO12 Pin = 12 // peripherals: PWM6 channel A
-	GPIO13 Pin = 13
+	GPIO13 Pin = 13 // peripherals: PWM6 channel B
-	GPIO14 Pin = 14
+	GPIO14 Pin = 14 // peripherals: PWM7 channel A
-	GPIO15 Pin = 15
+	GPIO15 Pin = 15 // peripherals: PWM7 channel B
-	GPIO16 Pin = 16
+	GPIO16 Pin = 16 // peripherals: PWM0 channel A
-	GPIO17 Pin = 17
+	GPIO17 Pin = 17 // peripherals: PWM0 channel B
-	GPIO18 Pin = 18
+	GPIO18 Pin = 18 // peripherals: PWM1 channel A
-	GPIO19 Pin = 19
+	GPIO19 Pin = 19 // peripherals: PWM1 channel B
-	GPIO20 Pin = 20
+	GPIO20 Pin = 20 // peripherals: PWM2 channel A
-	GPIO21 Pin = 21
+	GPIO21 Pin = 21 // peripherals: PWM2 channel B
-	GPIO22 Pin = 22
+	GPIO22 Pin = 22 // peripherals: PWM3 channel A
-	GPIO23 Pin = 23
+	GPIO23 Pin = 23 // peripherals: PWM3 channel B
-	GPIO24 Pin = 24
+	GPIO24 Pin = 24 // peripherals: PWM4 channel A
-	GPIO25 Pin = 25
+	GPIO25 Pin = 25 // peripherals: PWM4 channel B
-	GPIO26 Pin = 26
+	GPIO26 Pin = 26 // peripherals: PWM5 channel A
-	GPIO27 Pin = 27
+	GPIO27 Pin = 27 // peripherals: PWM5 channel B
-	GPIO28 Pin = 28
+	GPIO28 Pin = 28 // peripherals: PWM6 channel A
-	GPIO29 Pin = 29
+	GPIO29 Pin = 29 // peripherals: PWM6 channel B
 
 	// Analog pins
 	ADC0 Pin = GPIO26

src/machine/machine_rp2040_adc.go

@@ -17,8 +17,8 @@ const (
 	adc0_CH ADCChannel = iota
 	adc1_CH
 	adc2_CH
-	adc3_CH         // Note: GPIO29 not broken out on pico board
+	adc3_CH       // Note: GPIO29 not broken out on pico board
-	ADC_TEMP_SENSOR // Internal temperature sensor channel
+	adcTempSensor // Internal temperature sensor channel
 )
 
 // Used to serialise ADC sampling
@@ -75,19 +75,17 @@ func (a ADC) GetADCChannel() (c ADCChannel, err error) {
 	return c, err
 }
 
-// Configure sets the channel's associated pin to analog input mode or powers on the temperature sensor for ADC_TEMP_SENSOR.
+// Configure sets the channel's associated pin to analog input mode.
 // The powered on temperature sensor increases ADC_AVDD current by approximately 40 μA.
 func (c ADCChannel) Configure(config ADCConfig) error {
 	if config.Reference != 0 {
 		adcAref = config.Reference
 	}
-	if p, err := c.Pin(); err == nil {
+	p, err := c.Pin()
-		p.Configure(PinConfig{Mode: PinAnalog})
+	if err != nil {
-	}
+		return err
-	if c == ADC_TEMP_SENSOR {
-		// Enable temperature sensor bias source
-		rp.ADC.CS.SetBits(rp.ADC_CS_TS_EN)
 	}
+	p.Configure(PinConfig{Mode: pinAnalog})
 	return nil
 }
 
@@ -112,13 +110,16 @@ func (c ADCChannel) getVoltage() uint32 {
 }
 
 // ReadTemperature does a one-shot sample of the internal temperature sensor and returns a milli-celsius reading.
-// Only works on the ADC_TEMP_SENSOR channel. aka AINSEL=4. Other channels will return 0
+func ReadTemperature() (millicelsius int32) {
-func (c ADCChannel) ReadTemperature() (millicelsius uint32) {
+	if rp.ADC.CS.Get()&rp.ADC_CS_EN == 0 {
-	if c != ADC_TEMP_SENSOR {
+		InitADC()
-		return
 	}
+
+	// Enable temperature sensor bias source
+	rp.ADC.CS.SetBits(rp.ADC_CS_TS_EN)
+
 	// T = 27 - (ADC_voltage - 0.706)/0.001721
-	return (27000<<16 - (c.getVoltage()-706<<16)*581) >> 16
+	return (27000<<16 - (int32(adcTempSensor.getVoltage())-706<<16)*581) >> 16
 }
 
 // waitForReady spins waiting for the ADC peripheral to become ready.

src/machine/machine_rp2040_clocks.go

@@ -10,11 +10,6 @@ import (
 	"unsafe"
 )
 
-const (
-	KHz = 1000
-	MHz = 1000000
-)
-
 func CPUFrequency() uint32 {
 	return 125 * MHz
 }

src/machine/machine_rp2040_gpio.go

@@ -81,11 +81,13 @@ const (
 	PinInput
 	PinInputPulldown
 	PinInputPullup
-	PinAnalog
+
-	PinUART
+	// internal pin modes
-	PinPWM
+	pinAnalog
-	PinI2C
+	pinUART
-	PinSPI
+	pinPWM
+	pinI2C
+	pinSPI
 )
 
 func (p Pin) PortMaskSet() (*uint32, uint32) {
@@ -188,20 +190,20 @@ func (p Pin) Configure(config PinConfig) {
 	case PinInputPullup:
 		p.setFunc(fnSIO)
 		p.pullup()
-	case PinAnalog:
+	case pinAnalog:
 		p.setFunc(fnNULL)
 		p.pulloff()
-	case PinUART:
+	case pinUART:
 		p.setFunc(fnUART)
-	case PinPWM:
+	case pinPWM:
 		p.setFunc(fnPWM)
-	case PinI2C:
+	case pinI2C:
 		// IO config according to 4.3.1.3 of rp2040 datasheet.
 		p.setFunc(fnI2C)
 		p.pullup()
 		p.setSchmitt(true)
 		p.setSlew(false)
-	case PinSPI:
+	case pinSPI:
 		p.setFunc(fnSPI)
 	}
 }
@@ -226,12 +228,8 @@ type PinChange uint8
 
 // Pin change interrupt constants for SetInterrupt.
 const (
-	// PinLevelLow triggers whenever pin is at a low (around 0V) logic level.
-	PinLevelLow PinChange = 1 << iota
-	// PinLevelLow triggers whenever pin is at a high (around 3V) logic level.
-	PinLevelHigh
 	// Edge falling
-	PinFalling
+	PinFalling PinChange = 4 << iota
 	// Edge rising
 	PinRising
 )

src/machine/machine_rp2040_i2c.go

@@ -105,8 +105,8 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 	if config.Frequency == 0 {
 		config.Frequency = defaultBaud
 	}
-	config.SDA.Configure(PinConfig{PinI2C})
+	config.SDA.Configure(PinConfig{pinI2C})
-	config.SCL.Configure(PinConfig{PinI2C})
+	config.SCL.Configure(PinConfig{pinI2C})
 	return i2c.init(config)
 }
 

src/machine/machine_rp2040_pwm.go

@@ -92,7 +92,7 @@ func (pwm *pwmGroup) Channel(pin Pin) (channel uint8, err error) {
 	if pin > maxPWMPins || pwmGPIOToSlice(pin) != pwm.peripheral() {
 		return 3, ErrInvalidOutputPin
 	}
-	pin.Configure(PinConfig{PinPWM})
+	pin.Configure(PinConfig{pinPWM})
 	return pwmGPIOToChannel(pin), nil
 }
 

src/machine/machine_rp2040_rng.go

@@ -0,0 +1,42 @@
+//go:build rp2040
+// +build rp2040
+
+// Implementation based on code located here:
+// https://github.com/raspberrypi/pico-sdk/blob/master/src/rp2_common/pico_lwip/random.c
+
+package machine
+
+import (
+	"device/rp"
+)
+
+const numberOfCycles = 32
+
+// GetRNG returns 32 bits of semi-random data based on ring oscillator.
+//
+// Unlike some other implementations of GetRNG, these random numbers are not
+// cryptographically secure and must not be used for cryptographic operations
+// (nonces, etc).
+func GetRNG() (uint32, error) {
+	var val uint32
+	for i := 0; i < 4; i++ {
+		val = (val << 8) | uint32(roscRandByte())
+	}
+	return val, nil
+}
+
+var randomByte uint8
+
+func roscRandByte() uint8 {
+	var poly uint8
+	for i := 0; i < numberOfCycles; i++ {
+		if randomByte&0x80 != 0 {
+			poly = 0x35
+		} else {
+			poly = 0
+		}
+		randomByte = ((randomByte << 1) | uint8(rp.ROSC.GetRANDOMBIT()) ^ poly)
+		// TODO: delay a little because the random bit is a little slow
+	}
+	return randomByte
+}

src/machine/machine_rp2040_spi.go

@@ -38,10 +38,9 @@ type SPIConfig struct {
 }
 
 var (
-	ErrLSBNotSupported    = errors.New("SPI LSB unsupported on PL022")
+	ErrLSBNotSupported = errors.New("SPI LSB unsupported on PL022")
-	ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
+	ErrSPITimeout      = errors.New("SPI timeout")
-	ErrSPITimeout         = errors.New("SPI timeout")
+	ErrSPIBaud         = errors.New("SPI baud too low or above 66.5Mhz")
-	ErrSPIBaud            = errors.New("SPI baud too low or above 66.5Mhz")
 )
 
 type SPI struct {

src/machine/machine_rp2040_uart.go

@@ -42,8 +42,8 @@ func (uart *UART) Configure(config UARTConfig) error {
 		rp.UART0_UARTCR_TXE)
 
 	// set GPIO mux to UART for the pins
-	config.TX.Configure(PinConfig{Mode: PinUART})
+	config.TX.Configure(PinConfig{Mode: pinUART})
-	config.RX.Configure(PinConfig{Mode: PinUART})
+	config.RX.Configure(PinConfig{Mode: pinUART})
 
 	// Enable RX IRQ.
 	uart.Interrupt.SetPriority(0x80)

src/machine/machine_stm32_adc_f1.go

@@ -41,7 +41,7 @@ func InitADC() {
 
 // Configure configures an ADC pin to be able to read analog data.
 func (a ADC) Configure(ADCConfig) {
-	a.Pin.Configure(PinConfig{Mode: PinInputModeAnalog})
+	a.Pin.Configure(PinConfig{Mode: pinInputModeAnalog})
 
 	// set sample time
 	ch := a.getChannel()

src/machine/machine_stm32_adc_f4.go

@@ -36,7 +36,7 @@ func InitADC() {
 
 // Configure configures an ADC pin to be able to read analog data.
 func (a ADC) Configure(ADCConfig) {
-	a.Pin.ConfigureAltFunc(PinConfig{Mode: PinInputAnalog}, 0)
+	a.Pin.ConfigureAltFunc(PinConfig{Mode: pinInputAnalog}, 0)
 
 	// set sample time
 	ch := a.getChannel()

src/machine/machine_stm32_i2c_reva.go

@@ -137,7 +137,7 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 
 	// default to 100 kHz (Sm, standard mode) if no frequency is set
 	if config.Frequency == 0 {
-		config.Frequency = TWI_FREQ_100KHZ
+		config.Frequency = 100 * KHz
 	}
 
 	// configure I2C input clock

src/machine/machine_stm32_i2c_revb.go

@@ -102,8 +102,8 @@ func (i2c *I2C) Tx(addr uint16, w, r []byte) error {
 }
 
 func (i2c *I2C) configurePins(config I2CConfig) {
-	config.SCL.ConfigureAltFunc(PinConfig{Mode: PinModeI2CSCL}, i2c.AltFuncSelector)
+	config.SCL.ConfigureAltFunc(PinConfig{Mode: pinModeI2CSCL}, i2c.AltFuncSelector)
-	config.SDA.ConfigureAltFunc(PinConfig{Mode: PinModeI2CSDA}, i2c.AltFuncSelector)
+	config.SDA.ConfigureAltFunc(PinConfig{Mode: pinModeI2CSDA}, i2c.AltFuncSelector)
 }
 
 func (i2c *I2C) controllerTransmit(addr uint16, w []byte) error {

src/machine/machine_stm32_moder_gpio.go

@@ -14,29 +14,28 @@ import (
 const (
 	// Mode Flag
 	PinOutput        PinMode = 0
-	PinInput         PinMode = PinInputFloating
+	PinInput         PinMode = 1
-	PinInputFloating PinMode = 1
 	PinInputPulldown PinMode = 2
 	PinInputPullup   PinMode = 3
 
 	// for UART
-	PinModeUARTTX PinMode = 4
+	pinModeUARTTX PinMode = 4
-	PinModeUARTRX PinMode = 5
+	pinModeUARTRX PinMode = 5
 
 	// for I2C
-	PinModeI2CSCL PinMode = 6
+	pinModeI2CSCL PinMode = 6
-	PinModeI2CSDA PinMode = 7
+	pinModeI2CSDA PinMode = 7
 
 	// for SPI
-	PinModeSPICLK PinMode = 8
+	pinModeSPICLK PinMode = 8
-	PinModeSPISDO PinMode = 9
+	pinModeSPISDO PinMode = 9
-	PinModeSPISDI PinMode = 10
+	pinModeSPISDI PinMode = 10
 
 	// for analog/ADC
-	PinInputAnalog PinMode = 11
+	pinInputAnalog PinMode = 11
 
 	// for PWM
-	PinModePWMOutput PinMode = 12
+	pinModePWMOutput PinMode = 12
 )
 
 // Define several bitfields that have different names across chip families but
@@ -83,7 +82,7 @@ func (p Pin) ConfigureAltFunc(config PinConfig, altFunc uint8) {
 	switch config.Mode {
 
 	// GPIO
-	case PinInputFloating:
+	case PinInput:
 		port.MODER.ReplaceBits(gpioModeInput, gpioModeMask, pos)
 		port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
 	case PinInputPulldown:
@@ -97,24 +96,24 @@ func (p Pin) ConfigureAltFunc(config PinConfig, altFunc uint8) {
 		port.OSPEEDR.ReplaceBits(gpioOutputSpeedHigh, gpioOutputSpeedMask, pos)
 
 	// UART
-	case PinModeUARTTX:
+	case pinModeUARTTX:
 		port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
 		port.OSPEEDR.ReplaceBits(gpioOutputSpeedHigh, gpioOutputSpeedMask, pos)
 		port.PUPDR.ReplaceBits(gpioPullUp, gpioPullMask, pos)
 		p.SetAltFunc(altFunc)
-	case PinModeUARTRX:
+	case pinModeUARTRX:
 		port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
 		port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
 		p.SetAltFunc(altFunc)
 
 	// I2C
-	case PinModeI2CSCL:
+	case pinModeI2CSCL:
 		port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
 		port.OTYPER.ReplaceBits(stm32.GPIO_OTYPER_OT0_OpenDrain, stm32.GPIO_OTYPER_OT0_Msk, pos/2)
 		port.OSPEEDR.ReplaceBits(gpioOutputSpeedLow, gpioOutputSpeedMask, pos)
 		port.PUPDR.ReplaceBits(gpioPullUp, gpioPullMask, pos)
 		p.SetAltFunc(altFunc)
-	case PinModeI2CSDA:
+	case pinModeI2CSDA:
 		port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
 		port.OTYPER.ReplaceBits(stm32.GPIO_OTYPER_OT0_OpenDrain, stm32.GPIO_OTYPER_OT0_Msk, pos/2)
 		port.OSPEEDR.ReplaceBits(gpioOutputSpeedLow, gpioOutputSpeedMask, pos)
@@ -122,31 +121,31 @@ func (p Pin) ConfigureAltFunc(config PinConfig, altFunc uint8) {
 		p.SetAltFunc(altFunc)
 
 	// SPI
-	case PinModeSPICLK:
+	case pinModeSPICLK:
 		port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
 		port.OSPEEDR.ReplaceBits(gpioOutputSpeedHigh, gpioOutputSpeedMask, pos)
 		port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
 		p.SetAltFunc(altFunc)
-	case PinModeSPISDO:
+	case pinModeSPISDO:
 		port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
 		port.OSPEEDR.ReplaceBits(gpioOutputSpeedLow, gpioOutputSpeedMask, pos)
 		port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
 		p.SetAltFunc(altFunc)
-	case PinModeSPISDI:
+	case pinModeSPISDI:
 		port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
 		port.OSPEEDR.ReplaceBits(gpioOutputSpeedLow, gpioOutputSpeedMask, pos)
 		port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
 		p.SetAltFunc(altFunc)
 
 	// PWM
-	case PinModePWMOutput:
+	case pinModePWMOutput:
 		port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
 		port.OSPEEDR.ReplaceBits(gpioOutputSpeedHigh, gpioOutputSpeedMask, pos)
 		port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
 		p.SetAltFunc(altFunc)
 
 	// ADC
-	case PinInputAnalog:
+	case pinInputAnalog:
 		port.MODER.ReplaceBits(gpioModeAnalog, gpioModeMask, pos)
 	}
 }

src/machine/machine_stm32_tim.go

@@ -183,7 +183,7 @@ func (t *TIM) Channel(pin Pin) (uint8, error) {
 		for _, p := range ch.Pins {
 			if p.Pin == pin {
 				t.configurePin(uint8(chi), p)
-				//p.Pin.ConfigureAltFunc(PinConfig{Mode: PinModePWMOutput}, p.AltFunc)
+				//p.Pin.ConfigureAltFunc(PinConfig{Mode: pinModePWMOutput}, p.AltFunc)
 				return uint8(chi), nil
 			}
 		}

src/machine/machine_stm32_tim_moder.go

@@ -7,5 +7,5 @@ package machine
 // register (most MCUs except STM32F1 series).
 
 func (t *TIM) configurePin(channel uint8, pf PinFunction) {
-	pf.Pin.ConfigureAltFunc(PinConfig{Mode: PinModePWMOutput}, pf.AltFunc)
+	pf.Pin.ConfigureAltFunc(PinConfig{Mode: pinModePWMOutput}, pf.AltFunc)
 }

src/machine/machine_stm32f103.go

@@ -29,20 +29,20 @@ const (
 	PinOutput50MHz PinMode = 3 // Output mode, max speed 50MHz
 	PinOutput      PinMode = PinOutput2MHz
 
-	PinInputModeAnalog     PinMode = 0  // Input analog mode
+	pinInputModeAnalog     PinMode = 0  // Input analog mode
-	PinInputModeFloating   PinMode = 4  // Input floating mode
+	pinInputModeFloating   PinMode = 4  // Input floating mode
-	PinInputModePullUpDown PinMode = 8  // Input pull up/down mode
+	pinInputModePullUpDown PinMode = 8  // Input pull up/down mode
-	PinInputModeReserved   PinMode = 12 // Input mode (reserved)
+	pinInputModeReserved   PinMode = 12 // Input mode (reserved)
 
-	PinOutputModeGPPushPull   PinMode = 0  // Output mode general purpose push/pull
+	pinOutputModeGPPushPull   PinMode = 0  // Output mode general purpose push/pull
-	PinOutputModeGPOpenDrain  PinMode = 4  // Output mode general purpose open drain
+	pinOutputModeGPOpenDrain  PinMode = 4  // Output mode general purpose open drain
-	PinOutputModeAltPushPull  PinMode = 8  // Output mode alt. purpose push/pull
+	pinOutputModeAltPushPull  PinMode = 8  // Output mode alt. purpose push/pull
-	PinOutputModeAltOpenDrain PinMode = 12 // Output mode alt. purpose open drain
+	pinOutputModeAltOpenDrain PinMode = 12 // Output mode alt. purpose open drain
 
 	// Pull-up vs Pull down is not part of the CNF0 / CNF1 bits, but is
 	// controlled by PxODR.  Encoded using the 'spare' bit 5.
-	PinInputPulldown PinMode = PinInputModePullUpDown
+	PinInputPulldown PinMode = pinInputModePullUpDown
-	PinInputPullup   PinMode = PinInputModePullUpDown | 0x10
+	PinInputPullup   PinMode = pinInputModePullUpDown | 0x10
 )
 
 // Pin constants for all stm32f103 package sizes
@@ -166,7 +166,7 @@ func (p Pin) Configure(config PinConfig) {
 
 	// If configured for input pull-up or pull-down, set ODR
 	// for desired pull-up or pull-down.
-	if (config.Mode & 0xf) == PinInputModePullUpDown {
+	if (config.Mode & 0xf) == pinInputModePullUpDown {
 		var pullup uint32
 		if config.Mode == PinInputPullup {
 			pullup = 1
@@ -290,8 +290,8 @@ func (uart *UART) configurePins(config UARTConfig) {
 	default:
 		// use standard TX/RX pins PA9 and PA10
 	}
-	config.TX.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
+	config.TX.Configure(PinConfig{Mode: PinOutput50MHz + pinOutputModeAltPushPull})
-	config.RX.Configure(PinConfig{Mode: PinInputModeFloating})
+	config.RX.Configure(PinConfig{Mode: pinInputModeFloating})
 }
 
 // Determine the divisor for USARTs to get the given baudrate
@@ -363,9 +363,9 @@ func (spi SPI) getBaudRate(config SPIConfig) uint32 {
 
 // Configure SPI pins for input output and clock
 func (spi SPI) configurePins(config SPIConfig) {
-	config.SCK.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
+	config.SCK.Configure(PinConfig{Mode: PinOutput50MHz + pinOutputModeAltPushPull})
-	config.SDO.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
+	config.SDO.Configure(PinConfig{Mode: PinOutput50MHz + pinOutputModeAltPushPull})
-	config.SDI.Configure(PinConfig{Mode: PinInputModeFloating})
+	config.SDI.Configure(PinConfig{Mode: pinInputModeFloating})
 }
 
 //---------- I2C related types and code
@@ -390,8 +390,8 @@ func (i2c *I2C) configurePins(config I2CConfig) {
 		stm32.AFIO.MAPR.SetBits(stm32.AFIO_MAPR_I2C1_REMAP)
 	}
 
-	config.SDA.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltOpenDrain})
+	config.SDA.Configure(PinConfig{Mode: PinOutput50MHz + pinOutputModeAltOpenDrain})
-	config.SCL.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltOpenDrain})
+	config.SCL.Configure(PinConfig{Mode: PinOutput50MHz + pinOutputModeAltOpenDrain})
 }
 
 func (i2c *I2C) getFreqRange(config I2CConfig) uint32 {
@@ -717,7 +717,7 @@ func (t *TIM) configurePin(channel uint8, pf PinFunction) {
 		stm32.AFIO.MAPR.ReplaceBits(remap<<stm32.AFIO_MAPR2_TIM14_REMAP_Pos, stm32.AFIO_MAPR2_TIM14_REMAP_Msk, 0)
 	}
 
-	pf.Pin.Configure(PinConfig{Mode: PinOutput + PinOutputModeAltPushPull})
+	pf.Pin.Configure(PinConfig{Mode: PinOutput + pinOutputModeAltPushPull})
 }
 
 func (t *TIM) enableMainOutput() {

src/machine/machine_stm32f4.go

@@ -640,8 +640,8 @@ const (
 
 func (uart *UART) configurePins(config UARTConfig) {
 	// enable the alternate functions on the TX and RX pins
-	config.TX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTTX}, uart.TxAltFuncSelector)
+	config.TX.ConfigureAltFunc(PinConfig{Mode: pinModeUARTTX}, uart.TxAltFuncSelector)
-	config.RX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTRX}, uart.RxAltFuncSelector)
+	config.RX.ConfigureAltFunc(PinConfig{Mode: pinModeUARTRX}, uart.RxAltFuncSelector)
 }
 
 func (uart *UART) getBaudRateDivisor(baudRate uint32) uint32 {
@@ -674,9 +674,9 @@ func (spi SPI) config8Bits() {
 }
 
 func (spi SPI) configurePins(config SPIConfig) {
-	config.SCK.ConfigureAltFunc(PinConfig{Mode: PinModeSPICLK}, spi.AltFuncSelector)
+	config.SCK.ConfigureAltFunc(PinConfig{Mode: pinModeSPICLK}, spi.AltFuncSelector)
-	config.SDO.ConfigureAltFunc(PinConfig{Mode: PinModeSPISDO}, spi.AltFuncSelector)
+	config.SDO.ConfigureAltFunc(PinConfig{Mode: pinModeSPISDO}, spi.AltFuncSelector)
-	config.SDI.ConfigureAltFunc(PinConfig{Mode: PinModeSPISDI}, spi.AltFuncSelector)
+	config.SDI.ConfigureAltFunc(PinConfig{Mode: pinModeSPISDI}, spi.AltFuncSelector)
 }
 
 func (spi SPI) getBaudRate(config SPIConfig) uint32 {
@@ -723,8 +723,8 @@ type I2C struct {
 }
 
 func (i2c *I2C) configurePins(config I2CConfig) {
-	config.SCL.ConfigureAltFunc(PinConfig{Mode: PinModeI2CSCL}, i2c.AltFuncSelector)
+	config.SCL.ConfigureAltFunc(PinConfig{Mode: pinModeI2CSCL}, i2c.AltFuncSelector)
-	config.SDA.ConfigureAltFunc(PinConfig{Mode: PinModeI2CSDA}, i2c.AltFuncSelector)
+	config.SDA.ConfigureAltFunc(PinConfig{Mode: pinModeI2CSDA}, i2c.AltFuncSelector)
 }
 
 func (i2c *I2C) getFreqRange(config I2CConfig) uint32 {