ci: use native arm64 builder for arm64 binaries

Signed-off-by: deadprogram <ron@hybridgroup.com>

.circleci/config.yml

@@ -108,7 +108,7 @@ jobs:
       - image: golang:1.25-bullseye
     steps:
       - test-linux:
-          llvm: "21"
+          llvm: "20"
     resource_class: large
 
 workflows:

.github/workflows/build-macos.yml

@@ -39,7 +39,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.1'
+          go-version: '1.25.4'
           cache: true
       - name: Restore LLVM source cache
         uses: actions/cache/restore@v4
@@ -96,7 +96,7 @@ jobs:
       - name: Build TinyGo release tarball
         run: make release -j3
       - name: Test stdlib packages
-        run: make tinygo-test
+        run: make tinygo-test TEST_ADDITIONAL_FLAGS="-scheduler=tasks"
       - name: Make release artifact
         run: cp -p build/release.tar.gz build/tinygo${{ steps.version.outputs.version }}.darwin-${{ matrix.goarch }}.tar.gz
       - name: Publish release artifact
@@ -117,7 +117,7 @@ jobs:
     runs-on: macos-latest
     strategy:
       matrix:
-        version: [16, 17, 18, 19, 20, 21]
+        version: [16, 17, 18, 19, 20]
     steps:
       - name: Set up Homebrew
         uses: Homebrew/actions/setup-homebrew@master
@@ -134,15 +134,15 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.1'
+          go-version: '1.25.4'
           cache: true
       - name: Build TinyGo (LLVM ${{ matrix.version }})
         run: go install -tags=llvm${{ matrix.version }}
       - name: Check binary
         run: tinygo version
       - name: Build TinyGo (default LLVM)
-        if: matrix.version == 21
+        if: matrix.version == 20
         run: go install
       - name: Check binary
-        if: matrix.version == 21
+        if: matrix.version == 20
         run: tinygo version

.github/workflows/docker.yml

@@ -31,7 +31,7 @@ jobs:
           sudo rm -rf /usr/local/share/boost
           df -h
       - name: Check out the repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: recursive
       - name: Set up Docker Buildx
@@ -58,7 +58,7 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           push: true

.github/workflows/linux.yml

@@ -16,7 +16,15 @@ jobs:
     # Build Linux binaries, ready for release.
     # This runs inside an Alpine Linux container so we can more easily create a
     # statically linked binary.
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        goarch: [ amd64, arm64 ]
+        include:
+          - goarch: amd64
+            os: ubuntu-latest
+          - goarch: arm64
+            os: ubuntu-24.04-arm # TODO: use a -latest variant?
+    runs-on: ${{ matrix.os }}
     container:
       image: golang:1.25-alpine
     outputs:
@@ -31,7 +39,7 @@ jobs:
         # We're not on a multi-user machine, so this is safe.
         run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: true
       - name: Extract TinyGo version
@@ -40,7 +48,7 @@ jobs:
       - name: Cache Go
         uses: actions/cache@v4
         with:
-          key: go-cache-linux-alpine-v1-${{ hashFiles('go.mod') }}
+          key: go-cache-linux-alpine-${{ matrix.goarch }}-v1-${{ hashFiles('go.mod') }}
           path: |
             ~/.cache/go-build
             ~/go/pkg/mod
@@ -73,7 +81,7 @@ jobs:
         uses: actions/cache/restore@v4
         id: cache-llvm-build
         with:
-          key: llvm-build-20-linux-alpine-v1
+          key: llvm-build-19-linux-alpine-${{ matrix.goarch }}-v1
           path: llvm-build
       - name: Build LLVM
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -97,7 +105,7 @@ jobs:
         uses: actions/cache@v4
         id: cache-binaryen
         with:
-          key: binaryen-linux-alpine-v1
+          key: binaryen-linux-alpine-${{ matrix.goarch }}-v1
           path: build/wasm-opt
       - name: Build Binaryen
         if: steps.cache-binaryen.outputs.cache-hit != 'true'
@@ -116,28 +124,28 @@ jobs:
       - name: Build TinyGo release
         run: |
           make release deb -j3 STATIC=1
-          cp -p build/release.tar.gz /tmp/tinygo${{ steps.version.outputs.version }}.linux-amd64.tar.gz
-          cp -p build/release.deb    /tmp/tinygo_${{ steps.version.outputs.version }}_amd64.deb
+          cp -p build/release.tar.gz /tmp/tinygo${{ steps.version.outputs.version }}.linux-${{ matrix.goarch }}.tar.gz
+          cp -p build/release.deb    /tmp/tinygo_${{ steps.version.outputs.version }}_${{ matrix.goarch }}.deb
       - name: Publish release artifact
         uses: actions/upload-artifact@v4
         with:
-          name: linux-amd64-double-zipped-${{ steps.version.outputs.version }}
+          name: linux-${{ matrix.goarch }}-double-zipped-${{ steps.version.outputs.version }}
           path: |
-            /tmp/tinygo${{ steps.version.outputs.version }}.linux-amd64.tar.gz
-            /tmp/tinygo_${{ steps.version.outputs.version }}_amd64.deb
+            /tmp/tinygo${{ steps.version.outputs.version }}.linux-${{ matrix.goarch }}.tar.gz
+            /tmp/tinygo_${{ steps.version.outputs.version }}-${{ matrix.goarch }}.deb
   test-linux-build:
     # Test the binaries built in the build-linux job by running the smoke tests.
     runs-on: ubuntu-latest
     needs: build-linux
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: true
       - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: '1.25.0'
+          go-version: '1.25.4'
           cache: true
       - name: Install wasmtime
         uses: bytecodealliance/actions/wasmtime/setup@v1
@@ -164,7 +172,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: true
       - name: Install apt dependencies
@@ -179,9 +187,9 @@ jobs:
               simavr \
               ninja-build
       - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: '1.25.0'
+          go-version: '1.25.4'
           cache: true
       - name: Install Node.js
         uses: actions/setup-node@v4
@@ -272,11 +280,8 @@ jobs:
     # part of the release tarball.
     strategy:
       matrix:
-        goarch: [ arm, arm64 ]
+        goarch: [ arm ]
         include:
-          - goarch: arm64
-            toolchain: aarch64-linux-gnu
-            libc: arm64
           - goarch: arm
             toolchain: arm-linux-gnueabihf
             libc: armhf
@@ -284,7 +289,7 @@ jobs:
     needs: build-linux
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Get TinyGo version
         id: version
         run: ./.github/workflows/tinygo-extract-version.sh | tee -a "$GITHUB_OUTPUT"
@@ -296,9 +301,9 @@ jobs:
               g++-${{ matrix.toolchain }} \
               libc6-dev-${{ matrix.libc }}-cross
       - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: '1.25.0'
+          go-version: '1.25.4'
           cache: true
       - name: Restore LLVM source cache
         uses: actions/cache/restore@v4

.github/workflows/llvm.yml

@@ -25,7 +25,7 @@ jobs:
       contents: read
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: recursive
       - name: Set up Docker Buildx
@@ -52,7 +52,7 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           target: tinygo-llvm-build
           context: .

.github/workflows/nix.yml

@@ -21,7 +21,7 @@ jobs:
         # See: https://github.com/tinygo-org/tinygo/pull/4516#issuecomment-2416363668
         run: sudo apt-get remove llvm-18
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Pull musl, bdwgc
         run: |
             git submodule update --init lib/musl lib/bdwgc

.github/workflows/sizediff-install-pkgs.sh

@@ -2,11 +2,11 @@
 # still works after checking out the dev branch (that is, when going from LLVM
 # 16 to LLVM 17 for example, both Clang 16 and Clang 17 are installed).
 
-echo 'deb https://apt.llvm.org/noble/ llvm-toolchain-noble-21 main' | sudo tee /etc/apt/sources.list.d/llvm.list
+echo 'deb https://apt.llvm.org/noble/ llvm-toolchain-noble-20 main' | sudo tee /etc/apt/sources.list.d/llvm.list
 wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
 sudo apt-get update
 sudo apt-get install --no-install-recommends -y \
-    llvm-21-dev \
-    clang-21 \
-    libclang-21-dev \
-    lld-21
+    llvm-20-dev \
+    clang-20 \
+    libclang-20-dev \
+    lld-20

.github/workflows/sizediff.yml

@@ -20,7 +20,7 @@ jobs:
         run: |
           echo "$HOME/go/bin" >> $GITHUB_PATH
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 0 # fetch all history (no sparse checkout)
           submodules: true

.github/workflows/windows.yml

@@ -31,7 +31,7 @@ jobs:
         run: |
           scoop install ninja binaryen
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: true
       - name: Extract TinyGo version
@@ -39,9 +39,9 @@ jobs:
         shell: bash
         run: ./.github/workflows/tinygo-extract-version.sh | tee -a "$GITHUB_OUTPUT"
       - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: '1.25.0'
+          go-version: '1.25.4'
           cache: true
       - name: Restore cached LLVM source
         uses: actions/cache/restore@v4
@@ -143,11 +143,11 @@ jobs:
         run: |
           scoop install binaryen
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: '1.25.0'
+          go-version: '1.25.4'
           cache: true
       - name: Download TinyGo build
         uses: actions/download-artifact@v4
@@ -173,11 +173,11 @@ jobs:
           maximum-size: 24GB
           disk-root: "C:"
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: '1.25.0'
+          go-version: '1.25.4'
           cache: true
       - name: Download TinyGo build
         uses: actions/download-artifact@v4
@@ -209,11 +209,11 @@ jobs:
         run: |
           scoop install binaryen && scoop install wasmtime@29.0.1
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: '1.25.0'
+          go-version: '1.25.4'
           cache: true
       - name: Download TinyGo build
         uses: actions/download-artifact@v4

GNUmakefile

@@ -481,6 +481,7 @@ TEST_IOFS := false
 endif
 
 TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic'
+TEST_ADDITIONAL_FLAGS ?=
 
 # Test known-working standard library packages.
 # TODO: parallelize, and only show failing tests (no implied -v flag).
@@ -488,7 +489,7 @@ TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generi
 tinygo-test:
 	@# TestExtraMethods: used by many crypto packages and uses reflect.Type.Method which is not implemented.
 	@# TestParseAndBytesRoundTrip/P256/Generic: relies on t.Skip() which is not implemented
-	$(TINYGO) test $(TEST_SKIP_FLAG) $(TEST_PACKAGES_HOST) $(TEST_PACKAGES_SLOW)
+	$(TINYGO) test $(TEST_ADDITIONAL_FLAGS) $(TEST_SKIP_FLAG) $(TEST_PACKAGES_HOST) $(TEST_PACKAGES_SLOW)
 	@# io/fs requires os.ReadDir, not yet supported on windows or wasi. It also
 	@# requires a large stack-size. Hence, io/fs is only run conditionally.
 	@# For more details, see the comments on issue #3143.
@@ -621,6 +622,8 @@ smoketest: testchdir
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-rp2040      examples/device-id
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pico2-ice           examples/blinky1
+	@$(MD5SUM) test.hex
 	# test simulated boards on play.tinygo.org
 ifneq ($(WASM), 0)
 	GOOS=js GOARCH=wasm $(TINYGO) build -size short -o test.wasm -tags=arduino              examples/blinky1

builder/bdwgc.go

@@ -30,7 +30,10 @@ var BoehmGC = Library{
 			// Use a minimal environment.
 			"-DNO_MSGBOX_ON_ERROR", // don't call MessageBoxA on Windows
 			"-DDONT_USE_ATEXIT",
-			"-DNO_GETENV",
+			"-DNO_GETENV",          // smaller binary, more predictable configuration
+			"-DNO_CLOCK",           // don't use system clock
+			"-DNO_DEBUGGING",       // reduce code size
+			"-DGC_NO_FINALIZATION", // finalization is not used at the moment
 
 			// Special flag to work around the lack of __data_start in ld.lld.
 			// TODO: try to fix this in LLVM/lld directly so we don't have to
@@ -39,6 +42,8 @@ var BoehmGC = Library{
 
 			// Do not scan the stack. We have our own mechanism to do this.
 			"-DSTACK_NOT_SCANNED",
+			"-DNO_PROC_STAT",  // we scan the stack manually (don't read /proc/self/stat on Linux)
+			"-DSTACKBOTTOM=0", // dummy value, we scan the stack manually
 
 			// Assertions can be enabled while debugging GC issues.
 			//"-DGC_ASSERTIONS",
@@ -63,7 +68,6 @@ var BoehmGC = Library{
 			"blacklst.c",
 			"dbg_mlc.c",
 			"dyn_load.c",
-			"finalize.c",
 			"headers.c",
 			"mach_dep.c",
 			"malloc.c",
@@ -71,7 +75,6 @@ var BoehmGC = Library{
 			"mark_rts.c",
 			"misc.c",
 			"new_hblk.c",
-			"obj_map.c",
 			"os_dep.c",
 			"reclaim.c",
 		}

builder/config.go

@@ -33,10 +33,13 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 	if err != nil {
 		return nil, err
 	}
-	if gorootMajor != 1 || gorootMinor < minorMin || gorootMinor > minorMax {
-		// Note: when this gets updated, also update the Go compatibility matrix:
-		// https://github.com/tinygo-org/tinygo-site/blob/dev/content/docs/reference/go-compat-matrix.md
-		return nil, fmt.Errorf("requires go version 1.%d through 1.%d, got go%d.%d", minorMin, minorMax, gorootMajor, gorootMinor)
+
+	if options.GoCompatibility {
+		if gorootMajor != 1 || gorootMinor < minorMin || gorootMinor > minorMax {
+			// Note: when this gets updated, also update the Go compatibility matrix:
+			// https://github.com/tinygo-org/tinygo-site/blob/dev/content/docs/reference/go-compat-matrix.md
+			return nil, fmt.Errorf("requires go version 1.%d through 1.%d, got go%d.%d", minorMin, minorMax, gorootMajor, gorootMinor)
+		}
 	}
 
 	// Check that the Go toolchain version isn't too new, if we haven't been

builder/sizes_test.go

@@ -43,8 +43,8 @@ func TestBinarySize(t *testing.T) {
 	tests := []sizeTest{
 		// microcontrollers
 		{"hifive1b", "examples/echo", 3884, 280, 0, 2268},
-		{"microbit", "examples/serial", 2924, 388, 8, 2272},
-		{"wioterminal", "examples/pininterrupt", 7365, 1491, 116, 6912},
+		{"microbit", "examples/serial", 2844, 360, 8, 2272},
+		{"wioterminal", "examples/pininterrupt", 7349, 1491, 116, 6912},
 
 		// TODO: also check wasm. Right now this is difficult, because
 		// wasm binaries are run through wasm-opt and therefore the

cgo/libclang.go

@@ -21,10 +21,6 @@ import (
 )
 
 /*
-// Hide a warning in LLVM 21 that doesn't apply to us (appears to be a side
-// effect of how CGo processes C header files).
-#cgo CFLAGS: -Wno-deprecated-declarations
-
 #include <clang-c/Index.h> // If this fails, libclang headers aren't available. Please take a look here: https://tinygo.org/docs/guides/build/
 #include <llvm/Config/llvm-config.h>
 #include <stdlib.h>

cgo/libclang_config_llvm20.go

@@ -1,4 +1,4 @@
-//go:build !byollvm && llvm20
+//go:build !byollvm && !llvm15 && !llvm16 && !llvm17 && !llvm18 && !llvm19
 
 package cgo
 

cgo/libclang_config_llvm21.go

@@ -1,15 +0,0 @@
-//go:build !byollvm && !llvm15 && !llvm16 && !llvm17 && !llvm18 && !llvm19 && !llvm20
-
-package cgo
-
-/*
-#cgo linux        CFLAGS:  -I/usr/include/llvm-21 -I/usr/include/llvm-c-21 -I/usr/lib/llvm-21/include
-#cgo darwin,amd64 CFLAGS:  -I/usr/local/opt/llvm@21/include
-#cgo darwin,arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@21/include
-#cgo freebsd      CFLAGS:  -I/usr/local/llvm21/include
-#cgo linux        LDFLAGS: -L/usr/lib/llvm-21/lib -lclang
-#cgo darwin,amd64 LDFLAGS: -L/usr/local/opt/llvm@21/lib -lclang
-#cgo darwin,arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@21/lib -lclang
-#cgo freebsd      LDFLAGS: -L/usr/local/llvm21/lib -lclang
-*/
-import "C"

compileopts/config.go

@@ -226,7 +226,7 @@ func (c *Config) StackSize() uint64 {
 
 // MaxStackAlloc returns the size of the maximum allocation to put on the stack vs heap.
 func (c *Config) MaxStackAlloc() uint64 {
-	if c.StackSize() > 32*1024 {
+	if c.StackSize() >= 16*1024 {
 		return 1024
 	}
 

compileopts/options.go

@@ -59,6 +59,7 @@ type Options struct {
 	WITPackage      string // pass through to wasm-tools component embed invocation
 	WITWorld        string // pass through to wasm-tools component embed -w option
 	ExtLDFlags      []string
+	GoCompatibility bool // enable to check for Go version compatibility
 }
 
 // Verify performs a validation on the given options, raising an error if options are not valid.

compiler/calls.go

@@ -32,6 +32,9 @@ const (
 	// Whether this is a full or partial Go parameter (int, slice, etc).
 	// The extra context parameter is not a Go parameter.
 	paramIsGoParam = 1 << iota
+
+	// Whether this is a readonly parameter (for example, a string pointer).
+	paramIsReadonly
 )
 
 // createRuntimeCallCommon creates a runtime call. Use createRuntimeCall or
@@ -167,6 +170,7 @@ func (c *compilerContext) flattenAggregateType(t llvm.Type, name string, goType
 				continue
 			}
 			suffix := strconv.Itoa(i)
+			isString := false
 			if goType != nil {
 				// Try to come up with a good suffix for this struct field,
 				// depending on which Go type it's based on.
@@ -183,12 +187,16 @@ func (c *compilerContext) flattenAggregateType(t llvm.Type, name string, goType
 						suffix = []string{"r", "i"}[i]
 					case types.String:
 						suffix = []string{"data", "len"}[i]
+						isString = true
 					}
 				case *types.Signature:
 					suffix = []string{"context", "funcptr"}[i]
 				}
 			}
 			subInfos := c.flattenAggregateType(subfield, name+"."+suffix, extractSubfield(goType, i))
+			if isString {
+				subInfos[0].flags |= paramIsReadonly
+			}
 			paramInfos = append(paramInfos, subInfos...)
 		}
 		return paramInfos

compiler/compiler.go

@@ -84,7 +84,6 @@ type compilerContext struct {
 	funcPtrType      llvm.Type // pointer in function address space (1 for AVR, 0 elsewhere)
 	funcPtrAddrSpace int
 	uintptrType      llvm.Type
-	nocaptureAttr    llvm.Attribute
 	program          *ssa.Program
 	diagnostics      []error
 	functionInfos    map[*ssa.Function]functionInfo
@@ -136,13 +135,6 @@ func newCompilerContext(moduleName string, machine llvm.TargetMachine, config *C
 	c.funcPtrType = dummyFunc.Type()
 	dummyFunc.EraseFromParentAsFunction()
 
-	// The attribute "nocapture" changed to "captures(none)" in LLVM 21.
-	if llvmutil.Version() < 21 {
-		c.nocaptureAttr = c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0)
-	} else {
-		c.nocaptureAttr = c.ctx.CreateEnumAttribute(llvm.AttributeKindID("captures"), 0)
-	}
-
 	return c
 }
 

compiler/inlineasm.go

@@ -38,10 +38,10 @@ func (b *builder) createInlineAsm(args []ssa.Value) (llvm.Value, error) {
 // provided immediately. For example:
 //
 //	arm.AsmFull(
-//	    "str {value}, {result}",
+//	    "str {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 func (b *builder) createInlineAsmFull(instr *ssa.CallCommon) (llvm.Value, error) {
 	asmString := constant.StringVal(instr.Args[0].(*ssa.Const).Value)

compiler/map.go

@@ -250,6 +250,9 @@ func (b *builder) createMapIteratorNext(rangeVal ssa.Value, llvmRangeVal, it llv
 func hashmapIsBinaryKey(keyType types.Type) bool {
 	switch keyType := keyType.Underlying().(type) {
 	case *types.Basic:
+		// TODO: unsafe.Pointer is also a binary key, but to support that we
+		// need to fix an issue with interp first (see
+		// https://github.com/tinygo-org/tinygo/pull/4898).
 		return keyType.Info()&(types.IsBoolean|types.IsInteger) != 0
 	case *types.Pointer:
 		return true

compiler/symbol.go

@@ -139,7 +139,13 @@ func (c *compilerContext) getFunction(fn *ssa.Function) (llvm.Type, llvm.Value)
 			// not.
 			// (It may be safe to add the nocapture parameter to the context
 			// parameter, but I'd like to stay on the safe side here).
-			llvmFn.AddAttributeAtIndex(i+1, c.nocaptureAttr)
+			nocapture := c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0)
+			llvmFn.AddAttributeAtIndex(i+1, nocapture)
+		}
+		if paramInfo.flags&paramIsReadonly != 0 && paramInfo.llvmType.TypeKind() == llvm.PointerTypeKind {
+			// Readonly pointer parameters (like strings) benefit from being marked as readonly.
+			readonly := c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0)
+			llvmFn.AddAttributeAtIndex(i+1, readonly)
 		}
 	}
 
@@ -152,7 +158,7 @@ func (c *compilerContext) getFunction(fn *ssa.Function) (llvm.Type, llvm.Value)
 		// Mark it as noreturn so LLVM can optimize away code.
 		llvmFn.AddFunctionAttr(c.ctx.CreateEnumAttribute(llvm.AttributeKindID("noreturn"), 0))
 	case "internal/abi.NoEscape":
-		llvmFn.AddAttributeAtIndex(1, c.nocaptureAttr)
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 	case "runtime.alloc":
 		// Tell the optimizer that runtime.alloc is an allocator, meaning that it
 		// returns values that are never null and never alias to an existing value.
@@ -174,25 +180,25 @@ func (c *compilerContext) getFunction(fn *ssa.Function) (llvm.Type, llvm.Value)
 	case "runtime.sliceAppend":
 		// Appending a slice will only read the to-be-appended slice, it won't
 		// be modified.
-		llvmFn.AddAttributeAtIndex(2, c.nocaptureAttr)
+		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
 	case "runtime.sliceCopy":
 		// Copying a slice won't capture any of the parameters.
 		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("writeonly"), 0))
-		llvmFn.AddAttributeAtIndex(1, c.nocaptureAttr)
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
-		llvmFn.AddAttributeAtIndex(2, c.nocaptureAttr)
+		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 	case "runtime.stringFromBytes":
-		llvmFn.AddAttributeAtIndex(1, c.nocaptureAttr)
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
 	case "runtime.stringFromRunes":
-		llvmFn.AddAttributeAtIndex(1, c.nocaptureAttr)
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
 	case "runtime.trackPointer":
 		// This function is necessary for tracking pointers on the stack in a
 		// portable way (see gc_stack_portable.go). Indicate to the optimizer
 		// that the only thing we'll do is read the pointer.
-		llvmFn.AddAttributeAtIndex(1, c.nocaptureAttr)
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
 	case "__mulsi3", "__divmodsi4", "__udivmodsi4":
 		if strings.Split(c.Triple, "-")[0] == "avr" {
@@ -227,9 +233,11 @@ func (c *compilerContext) getFunction(fn *ssa.Function) (llvm.Type, llvm.Value)
 
 			llvmFn.AddFunctionAttr(c.ctx.CreateStringAttribute("wasm-import-name", info.wasmName))
 		}
+		nocaptureKind := llvm.AttributeKindID("nocapture")
+		nocapture := c.ctx.CreateEnumAttribute(nocaptureKind, 0)
 		for i, typ := range paramTypes {
 			if typ.TypeKind() == llvm.PointerTypeKind {
-				llvmFn.AddAttributeAtIndex(i+1, c.nocaptureAttr)
+				llvmFn.AddAttributeAtIndex(i+1, nocapture)
 			}
 		}
 	}

compiler/syscall.go

@@ -74,6 +74,14 @@ func (b *builder) createRawSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 		return b.CreateCall(fnType, target, args, ""), nil
 
 	case b.GOARCH == "arm" && b.GOOS == "linux":
+		if arch := b.archFamily(); arch != "arm" {
+			// Some targets pretend to be linux/arm for compatibility but aren't
+			// actually such a system. Make sure we emit an error instead of
+			// creating inline assembly that will fail to compile.
+			// See: https://github.com/tinygo-org/tinygo/issues/4959
+			return llvm.Value{}, b.makeError(call.Pos(), "system calls are not supported: target emulates a linux/arm system on "+arch)
+		}
+
 		// Implement the EABI system call convention for Linux.
 		// Source: syscall(2) man page.
 		args := []llvm.Value{}

compiler/testdata/go1.20.ll

@@ -50,7 +50,7 @@ unsafe.String.throw:                              ; preds = %entry
 declare void @runtime.unsafeSlicePanic(ptr) #1
 
 ; Function Attrs: nounwind
-define hidden ptr @main.unsafeStringData(ptr %s.data, i32 %s.len, ptr %context) unnamed_addr #2 {
+define hidden ptr @main.unsafeStringData(ptr readonly %s.data, i32 %s.len, ptr %context) unnamed_addr #2 {
 entry:
   %stackalloc = alloca i8, align 1
   call void @runtime.trackPointer(ptr %s.data, ptr nonnull %stackalloc, ptr undef) #3

compiler/testdata/go1.21.ll

@@ -77,7 +77,7 @@ entry:
 }
 
 ; Function Attrs: nounwind
-define hidden %runtime._string @main.minString(ptr %a.data, i32 %a.len, ptr %b.data, i32 %b.len, ptr %context) unnamed_addr #2 {
+define hidden %runtime._string @main.minString(ptr readonly %a.data, i32 %a.len, ptr readonly %b.data, i32 %b.len, ptr %context) unnamed_addr #2 {
 entry:
   %0 = insertvalue %runtime._string zeroinitializer, ptr %a.data, 0
   %1 = insertvalue %runtime._string %0, i32 %a.len, 1
@@ -91,7 +91,7 @@ entry:
   ret %runtime._string %5
 }
 
-declare i1 @runtime.stringLess(ptr, i32, ptr, i32, ptr) #1
+declare i1 @runtime.stringLess(ptr readonly, i32, ptr readonly, i32, ptr) #1
 
 ; Function Attrs: nounwind
 define hidden i32 @main.maxInt(i32 %a, i32 %b, ptr %context) unnamed_addr #2 {
@@ -116,7 +116,7 @@ entry:
 }
 
 ; Function Attrs: nounwind
-define hidden %runtime._string @main.maxString(ptr %a.data, i32 %a.len, ptr %b.data, i32 %b.len, ptr %context) unnamed_addr #2 {
+define hidden %runtime._string @main.maxString(ptr readonly %a.data, i32 %a.len, ptr readonly %b.data, i32 %b.len, ptr %context) unnamed_addr #2 {
 entry:
   %0 = insertvalue %runtime._string zeroinitializer, ptr %a.data, 0
   %1 = insertvalue %runtime._string %0, i32 %a.len, 1

compiler/testdata/string.ll

@@ -31,13 +31,13 @@ entry:
 }
 
 ; Function Attrs: nounwind
-define hidden i32 @main.stringLen(ptr %s.data, i32 %s.len, ptr %context) unnamed_addr #2 {
+define hidden i32 @main.stringLen(ptr readonly %s.data, i32 %s.len, ptr %context) unnamed_addr #2 {
 entry:
   ret i32 %s.len
 }
 
 ; Function Attrs: nounwind
-define hidden i8 @main.stringIndex(ptr %s.data, i32 %s.len, i32 %index, ptr %context) unnamed_addr #2 {
+define hidden i8 @main.stringIndex(ptr readonly %s.data, i32 %s.len, i32 %index, ptr %context) unnamed_addr #2 {
 entry:
   %.not = icmp ult i32 %index, %s.len
   br i1 %.not, label %lookup.next, label %lookup.throw
@@ -55,16 +55,16 @@ lookup.throw:                                     ; preds = %entry
 declare void @runtime.lookupPanic(ptr) #1
 
 ; Function Attrs: nounwind
-define hidden i1 @main.stringCompareEqual(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
+define hidden i1 @main.stringCompareEqual(ptr readonly %s1.data, i32 %s1.len, ptr readonly %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
 entry:
   %0 = call i1 @runtime.stringEqual(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr undef) #3
   ret i1 %0
 }
 
-declare i1 @runtime.stringEqual(ptr, i32, ptr, i32, ptr) #1
+declare i1 @runtime.stringEqual(ptr readonly, i32, ptr readonly, i32, ptr) #1
 
 ; Function Attrs: nounwind
-define hidden i1 @main.stringCompareUnequal(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
+define hidden i1 @main.stringCompareUnequal(ptr readonly %s1.data, i32 %s1.len, ptr readonly %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
 entry:
   %0 = call i1 @runtime.stringEqual(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr undef) #3
   %1 = xor i1 %0, true
@@ -72,16 +72,16 @@ entry:
 }
 
 ; Function Attrs: nounwind
-define hidden i1 @main.stringCompareLarger(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
+define hidden i1 @main.stringCompareLarger(ptr readonly %s1.data, i32 %s1.len, ptr readonly %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
 entry:
   %0 = call i1 @runtime.stringLess(ptr %s2.data, i32 %s2.len, ptr %s1.data, i32 %s1.len, ptr undef) #3
   ret i1 %0
 }
 
-declare i1 @runtime.stringLess(ptr, i32, ptr, i32, ptr) #1
+declare i1 @runtime.stringLess(ptr readonly, i32, ptr readonly, i32, ptr) #1
 
 ; Function Attrs: nounwind
-define hidden i8 @main.stringLookup(ptr %s.data, i32 %s.len, i8 %x, ptr %context) unnamed_addr #2 {
+define hidden i8 @main.stringLookup(ptr readonly %s.data, i32 %s.len, i8 %x, ptr %context) unnamed_addr #2 {
 entry:
   %0 = zext i8 %x to i32
   %.not = icmp ugt i32 %s.len, %0

go.mod

@@ -18,7 +18,7 @@ require (
 	golang.org/x/sys v0.30.0
 	golang.org/x/tools v0.30.0
 	gopkg.in/yaml.v2 v2.4.0
-	tinygo.org/x/go-llvm v0.0.0-20250916101410-63740cfada08
+	tinygo.org/x/go-llvm v0.0.0-20250422114502-b8f170971e74
 )
 
 require (

go.sum

@@ -58,5 +58,5 @@ 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 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-tinygo.org/x/go-llvm v0.0.0-20250916101410-63740cfada08 h1:vvEVYF4Qb38C25U8Ae/1QUWlCSp4pIE0PR+/BwNPvBU=
-tinygo.org/x/go-llvm v0.0.0-20250916101410-63740cfada08/go.mod h1:GFbusT2VTA4I+l4j80b17KFK+6whv69Wtny5U+T8RR0=
+tinygo.org/x/go-llvm v0.0.0-20250422114502-b8f170971e74 h1:ovavgTdIBWCH8YWlcfq9gkpoyT1+IxMKSn+Df27QwE8=
+tinygo.org/x/go-llvm v0.0.0-20250422114502-b8f170971e74/go.mod h1:GFbusT2VTA4I+l4j80b17KFK+6whv69Wtny5U+T8RR0=

interp/interpreter.go

@@ -577,7 +577,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 						// runtime instead of at compile time. But we need to
 						// revert any changes made by the call first.
 						if r.debug {
-							fmt.Fprintln(os.Stderr, indent+"!! revert because of error:", callErr.Err)
+							fmt.Fprintln(os.Stderr, indent+"!! revert because of error:", callErr.Error())
 						}
 						callMem.revert()
 						err := r.runAtRuntime(fn, inst, locals, &mem, indent)

main.go

@@ -1635,6 +1635,7 @@ func main() {
 	cpuprofile := flag.String("cpuprofile", "", "cpuprofile output")
 	monitor := flag.Bool("monitor", false, "enable serial monitor")
 	baudrate := flag.Int("baudrate", 115200, "baudrate of serial monitor")
+	gocompatibility := flag.Bool("go-compatibility", true, "enable to check for Go versions compatibility, you can also configure this by setting the TINYGO_GOCOMPATIBILITY environment variable")
 
 	// Internal flags, that are only intended for TinyGo development.
 	printIR := flag.Bool("internal-printir", false, "print LLVM IR")
@@ -1712,6 +1713,16 @@ func main() {
 		ocdCommands = strings.Split(*ocdCommandsString, ",")
 	}
 
+	val, ok := os.LookupEnv("TINYGO_GOCOMPATIBILITY")
+	if ok {
+		b, err := strconv.ParseBool(val)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "could not parse TINYGO_GOCOMPATIBILITY value %q: %v\n", val, err)
+			os.Exit(1)
+		}
+		*gocompatibility = b
+	}
+
 	options := &compileopts.Options{
 		GOOS:            goenv.Get("GOOS"),
 		GOARCH:          goenv.Get("GOARCH"),
@@ -1748,6 +1759,7 @@ func main() {
 		Timeout:         *timeout,
 		WITPackage:      witPackage,
 		WITWorld:        witWorld,
+		GoCompatibility: *gocompatibility,
 	}
 	if *printCommands {
 		options.PrintCommands = printCommand

src/device/arm/arm.go

@@ -48,10 +48,10 @@ func Asm(asm string)
 // recognizes template values in the form {name}, like so:
 //
 //	arm.AsmFull(
-//	    "str {value}, {result}",
+//	    "str {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 //
 // You can use {} in the asm string (which expands to a register) to set the

src/device/arm/cortexm.S

@@ -1,29 +1,6 @@
 .syntax unified
 .cfi_sections .debug_frame
 
-.section .text.HardFault_Handler
-.global  HardFault_Handler
-.type    HardFault_Handler, %function
-HardFault_Handler:
-    .cfi_startproc
-    // Put the old stack pointer in the first argument, for easy debugging. This
-    // is especially useful on Cortex-M0, which supports far fewer debug
-    // facilities.
-    mov r0, sp
-
-    // Load the default stack pointer from address 0 so that we can call normal
-    // functions again that expect a working stack. However, it will corrupt the
-    // old stack so the function below must not attempt to recover from this
-    // fault.
-    movs r3, #0
-    ldr r3, [r3]
-    mov sp, r3
-
-    // Continue handling this error in Go.
-    bl handleHardFault
-    .cfi_endproc
-.size HardFault_Handler, .-HardFault_Handler
-
 // This is a convenience function for semihosting support.
 // At some point, this should be replaced by inline assembly.
 .section .text.SemihostingCall

src/device/arm64/arm64.go

@@ -10,10 +10,10 @@ func Asm(asm string)
 // recognizes template values in the form {name}, like so:
 //
 //	arm.AsmFull(
-//	    "str {value}, {result}",
+//	    "str {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 //
 // You can use {} in the asm string (which expands to a register) to set the

src/device/asm.go

@@ -10,10 +10,10 @@ func Asm(asm string)
 // recognizes template values in the form {name}, like so:
 //
 //	arm.AsmFull(
-//	    "str {value}, {result}",
+//	    "str {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 //
 // You can use {} in the asm string (which expands to a register) to set the

src/device/riscv/riscv.go

@@ -10,10 +10,10 @@ func Asm(asm string)
 // recognizes template values in the form {name}, like so:
 //
 //	arm.AsmFull(
-//	    "st {value}, {result}",
+//	    "st {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 //
 // You can use {} in the asm string (which expands to a register) to set the

src/machine/board_fe310.go

@@ -15,8 +15,8 @@ const (
 	P09 Pin = 9
 	P10 Pin = 10
 	P11 Pin = 11
-	P12 Pin = 12
-	P13 Pin = 13
+	P12 Pin = 12 // peripherals: I2C0 SDA
+	P13 Pin = 13 // peripherals: I2C0 SCL
 	P14 Pin = 14
 	P15 Pin = 15
 	P16 Pin = 16

src/machine/board_pico2_ice.go

@@ -0,0 +1,173 @@
+//go:build pico2_ice
+
+// Most of the info is from
+// https://pico2-ice.tinyvision.ai/md_pinout.html although
+// (2025-09-07) RP4 appears twice in that pinout - the schematic is
+// more clear. Consistent with other RPi boards, we use GPn instead of
+// RPn to reference the RPi connected pins.
+
+package machine
+
+// GPIO pins
+const (
+	GP0  = GPIO0
+	GP1  = GPIO1
+	GP2  = GPIO2
+	GP3  = GPIO3
+	GP4  = GPIO4
+	GP5  = GPIO5
+	GP6  = GPIO6
+	GP7  = GPIO7
+	GP8  = GPIO8
+	GP9  = GPIO9
+	GP10 = GPIO10
+	GP11 = GPIO11
+	GP12 = GPIO12
+	GP13 = GPIO13
+	GP14 = GPIO14
+	GP15 = GPIO15
+	GP16 = GPIO16
+	GP17 = GPIO17
+	GP18 = GPIO18
+	GP19 = GPIO19
+	GP20 = GPIO20
+	GP21 = GPIO21
+	GP22 = GPIO22
+	GP23 = GPIO23
+	GP24 = GPIO24
+	GP25 = GPIO25
+	GP26 = GPIO26
+	GP27 = GPIO27
+	GP28 = GPIO28
+	GP29 = GPIO29
+	GP30 = GPIO30
+	GP31 = GPIO31
+	GP32 = GPIO32
+	GP33 = GPIO33
+	GP34 = GPIO34
+	GP35 = GPIO35
+	GP36 = GPIO36
+	GP37 = GPIO37
+	GP38 = GPIO38
+	GP39 = GPIO39
+	GP40 = GPIO40
+	GP41 = GPIO41
+	GP42 = GPIO42
+	GP43 = GPIO43
+	GP44 = GPIO44
+	GP45 = GPIO45
+	GP46 = GPIO46
+	GP47 = GPIO47
+
+	// RPi pins shared with ICE. The ICE number is what appears on
+	// the board silkscreen.
+	ICE9  = GP28
+	ICE11 = GP29
+	ICE14 = GP7
+	ICE15 = GP6
+	ICE16 = GP5
+	ICE17 = GP4
+	ICE18 = GP27
+	ICE19 = GP23
+	ICE20 = GP22
+	ICE21 = GP26
+	ICE23 = GP25
+	ICE25 = GP30
+	ICE26 = GP24
+	ICE27 = GP20
+
+	// FPGA Clock pin.
+	ICE35_G0 = GP21
+
+	// Silkscreen & Pinout names
+	ICE_SSN = ICE16
+	ICE_SO  = ICE14
+	ICE_SI  = ICE17
+	ICE_CK  = ICE15
+	SD      = GP2
+	SC      = GP3
+
+	FPGA_RSTN = GP31
+	A3        = GP32
+	A1        = GP33
+	A4        = GP34
+	A2        = GP35
+	B3        = GP36
+	B1        = GP37
+	B4        = GP38
+	B2        = GP39
+	N0        = GP40 // On the board these are labeled "~0"
+	N1        = GP41
+	N2        = GP42
+	N3        = GP43
+	N4        = GP44
+	N5        = GP45
+	N6        = GP46
+
+	// Functions from Schematic.
+	ICE_DONE = GP40
+	USB_BOOT = GP42
+
+	// Button
+	SW1     = GP42
+	BOOTSEL = GP42
+
+	// Tricolor LEDs
+	LED_RED   = GP1
+	LED_GREEN = GP0
+	LED_BLUE  = GP9
+
+	// Onboard LED
+	LED = LED_GREEN
+
+	// Onboard crystal oscillator frequency, in MHz.
+	xoscFreq = 12 // MHz
+)
+
+// This board does not define default i2c pins.
+const (
+	I2C0_SDA_PIN = NoPin
+	I2C0_SCL_PIN = NoPin
+	I2C1_SDA_PIN = NoPin
+	I2C1_SCL_PIN = NoPin
+)
+
+// SPI default pins
+const (
+	// Default Serial Clock Bus 0 for SPI communications
+	SPI0_SCK_PIN = GPIO18
+	// Default Serial Out Bus 0 for SPI communications
+	SPI0_SDO_PIN = GPIO19 // Tx
+	// Default Serial In Bus 0 for SPI communications
+	SPI0_SDI_PIN = GPIO16 // Rx
+
+	// Default Serial Clock Bus 1 for SPI communications
+	SPI1_SCK_PIN = GPIO10
+	// Default Serial Out Bus 1 for SPI communications
+	SPI1_SDO_PIN = GPIO11 // Tx
+	// Default Serial In Bus 1 for SPI communications
+	SPI1_SDI_PIN = GPIO12 // Rx
+)
+
+// UART pins
+const (
+	UART0_TX_PIN = GPIO0
+	UART0_RX_PIN = GPIO1
+	UART1_TX_PIN = GPIO8
+	UART1_RX_PIN = GPIO9
+	UART_TX_PIN  = UART0_TX_PIN
+	UART_RX_PIN  = UART0_RX_PIN
+)
+
+var DefaultUART = UART0
+
+// USB identifiers
+const (
+	usb_STRING_PRODUCT      = "Pico2"
+	usb_STRING_MANUFACTURER = "Raspberry Pi"
+)
+
+var (
+	usb_VID uint16 = 0x2E8A
+	usb_PID uint16 = 0x000A
+)

src/machine/machine_nrf52.go

@@ -69,3 +69,5 @@ const eraseBlockSizeValue = 4096
 func eraseBlockSize() int64 {
 	return eraseBlockSizeValue
 }
+
+const spiMaxBufferSize = 255 // from the datasheet: TXD.MAXCNT and RXD.MAXCNT

src/machine/machine_nrf52833.go

@@ -90,3 +90,5 @@ const eraseBlockSizeValue = 4096
 func eraseBlockSize() int64 {
 	return eraseBlockSizeValue
 }
+
+const spiMaxBufferSize = 0xffff // from the datasheet: TXD.MAXCNT and RXD.MAXCNT

src/machine/machine_nrf52840.go

@@ -108,3 +108,5 @@ const eraseBlockSizeValue = 4096
 func eraseBlockSize() int64 {
 	return eraseBlockSizeValue
 }
+
+const spiMaxBufferSize = 0xffff // from the datasheet: TXD.MAXCNT and RXD.MAXCNT

src/machine/machine_nrf52xxx.go

@@ -301,18 +301,16 @@ func (spi *SPI) Transfer(w byte) (byte, error) {
 // padded until they fit: if len(w) > len(r) the extra bytes received will be
 // dropped and if len(w) < len(r) extra 0 bytes will be sent.
 func (spi *SPI) Tx(w, r []byte) error {
-	// Unfortunately the hardware (on the nrf52832) only supports up to 255
-	// bytes in the buffers, so if either w or r is longer than that the
-	// transfer needs to be broken up in pieces.
-	// The nrf52840 supports far larger buffers however, which isn't yet
-	// supported.
+	// Unfortunately the hardware (on the nrf52832) only supports a limited
+	// amount of bytes in the buffers (depending on the chip), so if either w or
+	// r is longer than that the transfer needs to be broken up in pieces.
 	for len(r) != 0 || len(w) != 0 {
 		// Prepare the SPI transfer: set the DMA pointers and lengths.
 		// read buffer
 		nr := uint32(len(r))
 		if nr > 0 {
-			if nr > 255 {
-				nr = 255
+			if nr > spiMaxBufferSize {
+				nr = spiMaxBufferSize
 			}
 			spi.Bus.RXD.PTR.Set(uint32(uintptr(unsafe.Pointer(&r[0]))))
 			r = r[nr:]
@@ -322,8 +320,8 @@ func (spi *SPI) Tx(w, r []byte) error {
 		// write buffer
 		nw := uint32(len(w))
 		if nw > 0 {
-			if nw > 255 {
-				nw = 255
+			if nw > spiMaxBufferSize {
+				nw = spiMaxBufferSize
 			}
 			spi.Bus.TXD.PTR.Set(uint32(uintptr(unsafe.Pointer(&w[0]))))
 			w = w[nw:]

src/machine/machine_rp2_2040.go

@@ -124,6 +124,31 @@ const (
 	fnXIP pinFunc = 0
 )
 
+// validPins confirms that the SPI pin selection is a legitimate one
+// for the the 2040 chip.
+func (spi *SPI) validPins(config SPIConfig) error {
+	var okSDI, okSDO, okSCK bool
+	switch spi.Bus {
+	case rp.SPI0:
+		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
+		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23
+		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22
+	case rp.SPI1:
+		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
+		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
+		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
+	}
+	switch {
+	case !okSDI:
+		return errSPIInvalidSDI
+	case !okSDO:
+		return errSPIInvalidSDO
+	case !okSCK:
+		return errSPIInvalidSCK
+	}
+	return nil
+}
+
 // Configure configures the gpio pin as per mode.
 func (p Pin) Configure(config PinConfig) {
 	if p == NoPin {

src/machine/machine_rp2_2350a.go

@@ -2,6 +2,8 @@
 
 package machine
 
+import "device/rp"
+
 // Analog pins on RP2350a.
 const (
 	ADC0 Pin = GPIO26
@@ -12,3 +14,28 @@ const (
 	// fifth ADC channel.
 	thermADC = 30
 )
+
+// validPins confirms that the SPI pin selection is a legitimate one
+// for the the 2350a chip.
+func (spi *SPI) validPins(config SPIConfig) error {
+	var okSDI, okSDO, okSCK bool
+	switch spi.Bus {
+	case rp.SPI0:
+		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
+		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23
+		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22
+	case rp.SPI1:
+		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
+		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
+		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
+	}
+	switch {
+	case !okSDI:
+		return errSPIInvalidSDI
+	case !okSDO:
+		return errSPIInvalidSDO
+	case !okSCK:
+		return errSPIInvalidSCK
+	}
+	return nil
+}

src/machine/machine_rp2_2350b.go

@@ -2,6 +2,8 @@
 
 package machine
 
+import "device/rp"
+
 // RP2350B has additional pins.
 
 const (
@@ -46,3 +48,28 @@ var (
 	PWM10 = getPWMGroup(10)
 	PWM11 = getPWMGroup(11)
 )
+
+// validPins confirms that the SPI pin selection is a legitimate one
+// for the the 2350b chip.
+func (spi *SPI) validPins(config SPIConfig) error {
+	var okSDI, okSDO, okSCK bool
+	switch spi.Bus {
+	case rp.SPI0:
+		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20 || config.SDI == 32 || config.SDI == 36
+		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23 || config.SDO == 35 || config.SDO == 39
+		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22 || config.SCK == 34 || config.SCK == 38
+	case rp.SPI1:
+		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28 || config.SDI == 40 || config.SDI == 44
+		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27 || config.SDO == 31 || config.SDO == 43 || config.SDO == 47
+		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26 || config.SCK == 30 || config.SCK == 42 || config.SCK == 46
+	}
+	switch {
+	case !okSDI:
+		return errSPIInvalidSDI
+	case !okSDO:
+		return errSPIInvalidSDO
+	case !okSCK:
+		return errSPIInvalidSCK
+	}
+	return nil
+}

src/machine/machine_rp2_spi.go

@@ -108,7 +108,7 @@ func (spi *SPI) SetBaudRate(br uint32) error {
 	var prescale, postdiv uint32
 	freq := CPUFrequency()
 	for prescale = 2; prescale < 255; prescale += 2 {
-		if freq < (prescale+2)*256*br {
+		if uint64(freq) < uint64((prescale+2)*256)*uint64(br) {
 			break
 		}
 	}
@@ -165,27 +165,9 @@ func (spi *SPI) Configure(config SPIConfig) error {
 			config.SDI = SPI1_SDI_PIN
 		}
 	}
-	var okSDI, okSDO, okSCK bool
-	switch spi.Bus {
-	case rp.SPI0:
-		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
-		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23
-		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22
-	case rp.SPI1:
-		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
-		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
-		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
+	if err := spi.validPins(config); err != nil {
+		return err
 	}
-
-	switch {
-	case !okSDI:
-		return errSPIInvalidSDI
-	case !okSDO:
-		return errSPIInvalidSDO
-	case !okSCK:
-		return errSPIInvalidSCK
-	}
-
 	if config.Frequency == 0 {
 		config.Frequency = defaultBaud
 	}

src/runtime/arch_tinygowasm_malloc.go

@@ -8,16 +8,21 @@ import "unsafe"
 // code linked from other languages can allocate memory without colliding with
 // our GC allocations.
 
-var allocs = make(map[uintptr][]byte)
+// Map of allocations, where the key is the allocated pointer and the value is
+// the size of the allocation.
+// TODO: make this a map[unsafe.Pointer]uintptr, since that results in slightly
+// smaller binaries. But for that to work, unsafe.Pointer needs to be seen as a
+// binary key (which it is not at the moment).
+// See https://github.com/tinygo-org/tinygo/pull/4898 for details.
+var allocs = make(map[*byte]uintptr)
 
 //export malloc
 func libc_malloc(size uintptr) unsafe.Pointer {
 	if size == 0 {
 		return nil
 	}
-	buf := make([]byte, size)
-	ptr := unsafe.Pointer(&buf[0])
-	allocs[uintptr(ptr)] = buf
+	ptr := alloc(size, nil)
+	allocs[(*byte)(ptr)] = size
 	return ptr
 }
 
@@ -26,8 +31,8 @@ func libc_free(ptr unsafe.Pointer) {
 	if ptr == nil {
 		return
 	}
-	if _, ok := allocs[uintptr(ptr)]; ok {
-		delete(allocs, uintptr(ptr))
+	if _, ok := allocs[(*byte)(ptr)]; ok {
+		delete(allocs, (*byte)(ptr))
 	} else {
 		panic("free: invalid pointer")
 	}
@@ -48,18 +53,20 @@ func libc_realloc(oldPtr unsafe.Pointer, size uintptr) unsafe.Pointer {
 
 	// It's hard to optimize this to expand the current buffer with our GC, but
 	// it is theoretically possible. For now, just always allocate fresh.
-	buf := make([]byte, size)
+	// TODO: we could skip this if the new allocation is smaller than the old.
+	ptr := alloc(size, nil)
 
 	if oldPtr != nil {
-		if oldBuf, ok := allocs[uintptr(oldPtr)]; ok {
-			copy(buf, oldBuf)
-			delete(allocs, uintptr(oldPtr))
+		if oldSize, ok := allocs[(*byte)(oldPtr)]; ok {
+			oldBuf := unsafe.Slice((*byte)(oldPtr), oldSize)
+			newBuf := unsafe.Slice((*byte)(ptr), size)
+			copy(newBuf, oldBuf)
+			delete(allocs, (*byte)(oldPtr))
 		} else {
 			panic("realloc: invalid pointer")
 		}
 	}
 
-	ptr := unsafe.Pointer(&buf[0])
-	allocs[uintptr(ptr)] = buf
+	allocs[(*byte)(ptr)] = size
 	return ptr
 }

src/runtime/panic.go

@@ -93,6 +93,9 @@ func runtimePanicAt(addr unsafe.Pointer, msg string) {
 		trap()
 	}
 	if hasReturnAddr {
+		// Note: the string "panic: runtime error at " is also used in
+		// runtime_cortexm_hardfault.go. It is kept the same so that the string
+		// can be deduplicated by the compiler.
 		printstring("panic: runtime error at ")
 		printptr(uintptr(addr) - callInstSize)
 		printstring(": ")

src/runtime/runtime.go

@@ -57,6 +57,12 @@ func memzero(ptr unsafe.Pointer, size uintptr)
 // the current stack pointer in a platform-independent way.
 func stacksave() unsafe.Pointer
 
+// Special LLVM intrinsic that returns the SP register on entry to the calling
+// function.
+//
+//export llvm.sponentry.p0
+func llvm_sponentry() unsafe.Pointer
+
 //export strlen
 func strlen(ptr unsafe.Pointer) uintptr
 

src/runtime/runtime_atsamd21.go

@@ -273,6 +273,9 @@ func nanosecondsToTicks(ns int64) timeUnit {
 func sleepTicks(d timeUnit) {
 	for d != 0 {
 		ticks := uint32(d)
+		if d > 0xffff_ffff {
+			ticks = 0xffff_ffff
+		}
 		if !timerSleep(ticks) {
 			// Bail out early to handle a non-time interrupt.
 			return

src/runtime/runtime_atsamd51.go

@@ -266,6 +266,9 @@ func nanosecondsToTicks(ns int64) timeUnit {
 func sleepTicks(d timeUnit) {
 	for d != 0 {
 		ticks := uint32(d)
+		if d > 0xffff_ffff {
+			ticks = 0xffff_ffff
+		}
 		if !timerSleep(ticks) {
 			return
 		}

src/runtime/runtime_cortexm_hardfault.go

@@ -2,39 +2,25 @@
 
 package runtime
 
-import (
-	"unsafe"
-)
-
 // This function is called at HardFault.
-// Before this function is called, the stack pointer is reset to the initial
-// stack pointer (loaded from address 0x0) and the previous stack pointer is
-// passed as an argument to this function. This allows for easy inspection of
-// the stack the moment a HardFault occurs, but it means that the stack will be
-// corrupted by this function and thus this handler must not attempt to recover.
 //
 // For details, see:
 // https://community.arm.com/developer/ip-products/system/f/embedded-forum/3257/debugging-a-cortex-m0-hard-fault
 // https://blog.feabhas.com/2013/02/developing-a-generic-hard-fault-handler-for-arm-cortex-m3cortex-m4/
 //
-//export handleHardFault
-func handleHardFault(sp *interruptStack) {
-	print("fatal error: ")
-	if uintptr(unsafe.Pointer(sp)) < 0x20000000 {
-		print("stack overflow")
-	} else {
-		// TODO: try to find the cause of the hard fault. Especially on
-		// Cortex-M3 and higher it is possible to find more detailed information
-		// in special status registers.
-		print("HardFault")
-	}
-	print(" with sp=", sp)
-	if uintptr(unsafe.Pointer(&sp.PC)) >= 0x20000000 {
-		// Only print the PC if it points into memory.
-		// It may not point into memory during a stack overflow, so check that
-		// first before accessing the stack.
-		print(" pc=", sp.PC)
-	}
+//export HardFault_Handler
+func HardFault_Handler() {
+	// Obtain the stack pointer as it was on entry to the HardFault. It contains
+	// the registers that were pushed by the NVIC and that we can now read back
+	// to print the PC value at the time of the hard fault, for example.
+	sp := (*interruptStack)(llvm_sponentry())
+
+	// Note: by reusing the string "panic: runtime error at " we save a little
+	// bit in terms of code size as the string can be deduplicated.
+	print("panic: runtime error at ", sp.PC, ": HardFault with sp=", sp)
+	// TODO: try to find the cause of the hard fault. Especially on Cortex-M3
+	// and higher it is possible to find more detailed information in special
+	// status registers.
 	println()
 	abort()
 }

src/runtime/runtime_cortexm_hardfault_debug.go

@@ -18,8 +18,13 @@ const (
 
 // See runtime_cortexm_hardfault.go
 //
-//go:export handleHardFault
-func handleHardFault(sp *interruptStack) {
+//export HardFault_Handler
+func HardFault_Handler() {
+	// Obtain the stack pointer as it was on entry to the HardFault. It contains
+	// the registers that were pushed by the NVIC and that we can now read back
+	// to print the PC value at the time of the hard fault, for example.
+	sp := (*interruptStack)(llvm_sponentry())
+
 	fault := GetFaultStatus()
 	spValid := !fault.Bus().ImpreciseDataBusError()
 

src/runtime/runtime_nrf.go

@@ -78,6 +78,9 @@ func buffered() int {
 func sleepTicks(d timeUnit) {
 	for d != 0 {
 		ticks := uint32(d) & 0x7fffff // 23 bits (to be on the safe side)
+		if d > 0x7fffff {
+			ticks = 0x7fffff
+		}
 		rtc_sleep(ticks)
 		d -= timeUnit(ticks)
 	}

src/runtime/runtime_nrf52840.go

@@ -81,6 +81,9 @@ func buffered() int {
 func sleepTicks(d timeUnit) {
 	for d != 0 {
 		ticks := uint32(d) & 0x7fffff // 23 bits (to be on the safe side)
+		if d > 0x7fffff {
+			ticks = 0x7fffff
+		}
 		rtc_sleep(ticks)
 		d -= timeUnit(ticks)
 	}

src/syscall/libc_wasip2.go

@@ -212,6 +212,7 @@ func writeStream(stream *wasiStream, buf *byte, count uint, offset int64) int {
 			return -1
 		}
 		remaining -= len
+		src = src[len:]
 	}
 
 	return int(count)

src/testing/testing.go

@@ -10,6 +10,7 @@ package testing
 
 import (
 	"bytes"
+	"context"
 	"errors"
 	"flag"
 	"fmt"
@@ -78,6 +79,9 @@ type common struct {
 	tempDir    string
 	tempDirErr error
 	tempDirSeq int32
+
+	ctx       context.Context
+	cancelCtx context.CancelFunc
 }
 
 type logger struct {
@@ -152,6 +156,7 @@ func fmtDuration(d time.Duration) string {
 // TB is the interface common to T and B.
 type TB interface {
 	Cleanup(func())
+	Context() context.Context
 	Error(args ...interface{})
 	Errorf(format string, args ...interface{})
 	Fail()
@@ -307,6 +312,15 @@ func (c *common) Cleanup(f func()) {
 	c.cleanups = append(c.cleanups, f)
 }
 
+// Context returns a context that is canceled just before
+// Cleanup-registered functions are called.
+//
+// Cleanup functions can wait for any resources
+// that shut down on [context.Context.Done] before the test or benchmark completes.
+func (c *common) Context() context.Context {
+	return c.ctx
+}
+
 // TempDir returns a temporary directory for the test to use.
 // The directory is automatically removed by Cleanup when the test and
 // all its subtests complete.
@@ -447,6 +461,9 @@ func (c *common) runCleanup() {
 		if cleanup == nil {
 			return
 		}
+		if c.cancelCtx != nil {
+			c.cancelCtx()
+		}
 		cleanup()
 	}
 }
@@ -488,12 +505,15 @@ func (t *T) Run(name string, f func(t *T)) bool {
 	}
 
 	// Create a subtest.
+	ctx, cancelCtx := context.WithCancel(context.Background())
 	sub := T{
 		common: common{
-			output: &logger{logToStdout: flagVerbose},
-			name:   testName,
-			parent: &t.common,
-			level:  t.level + 1,
+			output:    &logger{logToStdout: flagVerbose},
+			name:      testName,
+			parent:    &t.common,
+			level:     t.level + 1,
+			ctx:       ctx,
+			cancelCtx: cancelCtx,
 		},
 		context: t.context,
 	}
@@ -606,9 +626,12 @@ func runTests(matchString func(pat, str string) (bool, error), tests []InternalT
 	ok = true
 
 	ctx := newTestContext(newMatcher(matchString, flagRunRegexp, "-test.run", flagSkipRegexp))
+	runCtx, cancelCtx := context.WithCancel(context.Background())
 	t := &T{
 		common: common{
-			output: &logger{logToStdout: flagVerbose},
+			output:    &logger{logToStdout: flagVerbose},
+			ctx:       runCtx,
+			cancelCtx: cancelCtx,
 		},
 		context: ctx,
 	}

targets/pico2-ice.json

@@ -0,0 +1,11 @@
+{
+    "inherits": [
+        "rp2350b"
+    ],
+    "build-tags": ["pico2_ice"],
+    "serial-port": ["2e8a:000A"],
+    "default-stack-size": 8192,
+    "ldflags": [
+        "--defsym=__flash_size=4M"
+    ]
+}