Release 0.41.1

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

.circleci/config.yml

@@ -96,7 +96,7 @@ jobs:
     # This tests our lowest supported versions of Go and LLVM, to make sure at
     # least the smoke tests still pass.
     docker:
-      - image: golang:1.22-bullseye
+      - image: golang:1.23-bullseye
     steps:
       - test-linux:
           llvm: "15"
@@ -105,7 +105,7 @@ jobs:
     # This tests the latest supported LLVM version when linking against system
     # libraries.
     docker:
-      - image: golang:1.25-bullseye
+      - image: golang:1.26-bookworm
     steps:
       - test-linux:
           llvm: "20"

.github/workflows/build-macos.yml

@@ -31,7 +31,7 @@ jobs:
         run: |
           HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu binaryen
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
       - name: Extract TinyGo version
@@ -40,10 +40,10 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Restore LLVM source cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-source
         with:
           key: llvm-source-20-${{ matrix.os }}-v1
@@ -57,7 +57,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Save LLVM source cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-source.outputs.cache-primary-key }}
@@ -68,7 +68,7 @@ jobs:
             llvm-project/lld/include
             llvm-project/llvm/include
       - name: Restore LLVM build cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
           key: llvm-build-20-${{ matrix.os }}-v2
@@ -85,7 +85,7 @@ jobs:
           make llvm-build
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Save LLVM build cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-build.outputs.cache-primary-key }}
@@ -101,16 +101,11 @@ jobs:
       - name: Make release artifact
         run: cp -p build/release.tar.gz build/tinygo${{ steps.version.outputs.version }}.darwin-${{ matrix.goarch }}.tar.gz
       - name: Publish release artifact
-        # Note: this release artifact is double-zipped, see:
-        # https://github.com/actions/upload-artifact/issues/39
-        # We can essentially pick one of these:
-        # - have a double-zipped artifact when downloaded from the UI
-        # - have a very slow artifact upload
-        # We're doing the former here, to keep artifact uploads fast.
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: darwin-${{ matrix.goarch }}-double-zipped-${{ steps.version.outputs.version }}
           path: build/tinygo${{ steps.version.outputs.version }}.darwin-${{ matrix.goarch }}.tar.gz
+          archive: false
       - name: Smoke tests
         run: make smoketest TINYGO=$(PWD)/build/tinygo
   test-macos-homebrew:
@@ -121,7 +116,7 @@ jobs:
         version: [16, 17, 18, 19, 20]
     steps:
       - name: Set up Homebrew
-        uses: Homebrew/actions/setup-homebrew@master
+        uses: Homebrew/actions/setup-homebrew@main
       - name: Fix Python symlinks
         run: |
           # Github runners have broken symlinks, so relink
@@ -130,12 +125,13 @@ jobs:
       - name: Install LLVM
         run: |
           brew install llvm@${{ matrix.version }}
+          brew link llvm@${{ matrix.version }}
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Build TinyGo (LLVM ${{ matrix.version }})
         run: go install -tags=llvm${{ matrix.version }}

.github/workflows/docker.yml

@@ -31,14 +31,14 @@ jobs:
           sudo rm -rf /usr/local/share/boost
           df -h
       - name: Check out the repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: recursive
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
       - name: Docker meta
         id: meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           images: |
             tinygo/tinygo-dev
@@ -47,18 +47,18 @@ jobs:
             type=sha,format=long
             type=raw,value=latest
       - name: Log in to Docker Hub
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
       - name: Log in to Github Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: .
           push: true

.github/workflows/linux.yml

@@ -18,12 +18,12 @@ jobs:
     # statically linked binary.
     runs-on: ubuntu-latest
     container:
-      image: golang:1.25-alpine
+      image: golang:1.26-alpine
     outputs:
       version: ${{ steps.version.outputs.version }}
     steps:
       - name: Install apk dependencies
-        # tar: needed for actions/cache@v4
+        # tar: needed for actions/cache@v5
         # git+openssh: needed for checkout (I think?)
         # ruby: needed to install fpm
         run: apk add tar git openssh make g++ ruby-dev mold
@@ -31,24 +31,24 @@ jobs:
         # We're not on a multi-user machine, so this is safe.
         run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
       - name: Extract TinyGo version
         id: version
         run: ./.github/workflows/tinygo-extract-version.sh | tee -a "$GITHUB_OUTPUT"
       - name: Cache Go
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
-          key: go-cache-linux-alpine-v1-${{ hashFiles('go.mod') }}
+          key: go-cache-linux-alpine-v2-${{ hashFiles('go.mod') }}
           path: |
             ~/.cache/go-build
             ~/go/pkg/mod
       - name: Restore LLVM source cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-source
         with:
-          key: llvm-source-20-linux-alpine-v1
+          key: llvm-source-20-linux-alpine-v2
           path: |
             llvm-project/clang/lib/Headers
             llvm-project/clang/include
@@ -59,7 +59,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Save LLVM source cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-source.outputs.cache-primary-key }}
@@ -70,10 +70,10 @@ jobs:
             llvm-project/lld/include
             llvm-project/llvm/include
       - name: Restore LLVM build cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
-          key: llvm-build-20-linux-alpine-v1
+          key: llvm-build-20-linux-alpine-v2
           path: llvm-build
       - name: Build LLVM
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -88,16 +88,16 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Save LLVM build cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-build.outputs.cache-primary-key }}
           path: llvm-build
       - name: Cache Binaryen
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: cache-binaryen
         with:
-          key: binaryen-linux-alpine-v1
+          key: binaryen-linux-alpine-v2
           path: build/wasm-opt
       - name: Build Binaryen
         if: steps.cache-binaryen.outputs.cache-hit != 'true'
@@ -118,26 +118,31 @@ jobs:
           make release deb -j3 STATIC=1
           cp -p build/release.tar.gz /tmp/tinygo${{ steps.version.outputs.version }}.linux-amd64.tar.gz
           cp -p build/release.deb    /tmp/tinygo_${{ steps.version.outputs.version }}_amd64.deb
-      - name: Publish release artifact
-        uses: actions/upload-artifact@v4
+      - name: "Publish release artifact: tarball"
+        uses: actions/upload-artifact@v7
         with:
-          name: linux-amd64-double-zipped-${{ steps.version.outputs.version }}
-          path: |
-            /tmp/tinygo${{ steps.version.outputs.version }}.linux-amd64.tar.gz
-            /tmp/tinygo_${{ steps.version.outputs.version }}_amd64.deb
+          name: tinygo${{ steps.version.outputs.version }}.linux-amd64.tar.gz
+          path: /tmp/tinygo${{ steps.version.outputs.version }}.linux-amd64.tar.gz
+          archive: false
+      - name: "Publish release artifact: Debian package"
+        uses: actions/upload-artifact@v7
+        with:
+          name: tinygo_${{ steps.version.outputs.version }}_amd64.deb
+          path: /tmp/tinygo_${{ steps.version.outputs.version }}_amd64.deb
+          archive: false
   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@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Install wasmtime
         uses: bytecodealliance/actions/wasmtime/setup@v1
@@ -146,9 +151,9 @@ jobs:
       - name: Install wasm-tools
         uses: bytecodealliance/actions/wasm-tools/setup@v1
       - name: Download release artifact
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
         with:
-          name: linux-amd64-double-zipped-${{ needs.build-linux.outputs.version }}
+          name: tinygo${{ needs.build-linux.outputs.version }}.linux-amd64.tar.gz
       - name: Extract release tarball
         run: |
           mkdir -p ~/lib
@@ -164,7 +169,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
       - name: Install apt dependencies
@@ -181,10 +186,10 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Install Node.js
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: '18'
       - name: Install wasmtime
@@ -194,7 +199,7 @@ jobs:
       - name: Setup `wasm-tools`
         uses: bytecodealliance/actions/wasm-tools/setup@v1
       - name: Restore LLVM source cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-source
         with:
           key: llvm-source-20-linux-asserts-v1
@@ -208,7 +213,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Save LLVM source cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-source.outputs.cache-primary-key }}
@@ -219,7 +224,7 @@ jobs:
             llvm-project/lld/include
             llvm-project/llvm/include
       - name: Restore LLVM build cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
           key: llvm-build-20-linux-asserts-v1
@@ -235,13 +240,13 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Save LLVM build cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-build.outputs.cache-primary-key }}
           path: llvm-build
       - name: Cache Binaryen
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: cache-binaryen
         with:
           key: binaryen-linux-asserts-v1
@@ -284,7 +289,7 @@ jobs:
     needs: build-linux
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Get TinyGo version
         id: version
         run: ./.github/workflows/tinygo-extract-version.sh | tee -a "$GITHUB_OUTPUT"
@@ -298,10 +303,10 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Restore LLVM source cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-source
         with:
           key: llvm-source-20-linux-v1
@@ -315,7 +320,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Save LLVM source cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-source.outputs.cache-primary-key }}
@@ -326,7 +331,7 @@ jobs:
             llvm-project/lld/include
             llvm-project/llvm/include
       - name: Restore LLVM build cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
           key: llvm-build-20-linux-${{ matrix.goarch }}-v1
@@ -344,13 +349,13 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Save LLVM build cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-build.outputs.cache-primary-key }}
           path: llvm-build
       - name: Cache Binaryen
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: cache-binaryen
         with:
           key: binaryen-linux-${{ matrix.goarch }}-v4
@@ -370,9 +375,9 @@ jobs:
         run: |
           make CROSS=${{ matrix.toolchain }}
       - name: Download amd64 release
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
         with:
-          name: linux-amd64-double-zipped-${{ needs.build-linux.outputs.version }}
+          name: tinygo${{ needs.build-linux.outputs.version }}.linux-amd64.tar.gz
       - name: Extract amd64 release
         run: |
           mkdir -p build/release
@@ -384,12 +389,17 @@ jobs:
       - name: Create ${{ matrix.goarch }} release
         run: |
           make release deb RELEASEONLY=1 DEB_ARCH=${{ matrix.libc }}
-          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.libc }}.deb
-      - name: Publish release artifact
-        uses: actions/upload-artifact@v4
+          cp -p build/release.tar.gz /tmp/tinygo${{ needs.build-linux.outputs.version }}.linux-${{ matrix.goarch }}.tar.gz
+          cp -p build/release.deb    /tmp/tinygo_${{ needs.build-linux.outputs.version }}_${{ matrix.libc }}.deb
+      - name: "Publish release artifact: tarball"
+        uses: actions/upload-artifact@v7
         with:
-          name: linux-${{ matrix.goarch }}-double-zipped-${{ steps.version.outputs.version }}
-          path: |
-            /tmp/tinygo${{ steps.version.outputs.version }}.linux-${{ matrix.goarch }}.tar.gz
-            /tmp/tinygo_${{ steps.version.outputs.version }}_${{ matrix.libc }}.deb
+          name: linux-${{ matrix.goarch }}-double-zipped-${{ needs.build-linux.outputs.version }}
+          path: /tmp/tinygo${{ needs.build-linux.outputs.version }}.linux-${{ matrix.goarch }}.tar.gz
+          archive: false
+      - name: "Publish release artifact: Debian package"
+        uses: actions/upload-artifact@v7
+        with:
+          name: linux-${{ matrix.goarch }}-double-zipped-${{ needs.build-linux.outputs.version }}
+          path: /tmp/tinygo_${{ needs.build-linux.outputs.version }}_${{ matrix.libc }}.deb
+          archive: false

.github/workflows/llvm.yml

@@ -25,14 +25,14 @@ jobs:
       contents: read
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: recursive
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
       - name: Docker meta
         id: meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           images: |
             tinygo/llvm-20
@@ -46,13 +46,13 @@ jobs:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
       - name: Log in to Github Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           target: tinygo-llvm-build
           context: .

.github/workflows/nix.yml

@@ -21,12 +21,12 @@ jobs:
         # See: https://github.com/tinygo-org/tinygo/pull/4516#issuecomment-2416363668
         run: sudo apt-get remove llvm-18
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Pull musl, bdwgc
         run: |
             git submodule update --init lib/musl lib/bdwgc
       - name: Restore LLVM source cache
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-source
         with:
           key: llvm-source-20-linux-nix-v1
@@ -36,7 +36,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Save LLVM source cache
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-source.outputs.cache-primary-key }}

.github/workflows/sizediff.yml

@@ -20,14 +20,14 @@ jobs:
         run: |
           echo "$HOME/go/bin" >> $GITHUB_PATH
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0 # fetch all history (no sparse checkout)
           submodules: true
       - name: Install apt dependencies
         run: ./.github/workflows/sizediff-install-pkgs.sh
       - name: Restore LLVM source cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: cache-llvm-source
         with:
           key: llvm-source-20-sizediff-v1
@@ -37,7 +37,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Cache Go
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           key: go-cache-linux-sizediff-v2-${{ hashFiles('go.mod') }}
           path: |

.github/workflows/windows.yml

@@ -24,14 +24,13 @@ jobs:
           maximum-size: 24GB
           disk-root: "C:"
       - uses: MinoruSekine/setup-scoop@v4
-        with:
-          scoop_update: 'false'
       - name: Install Dependencies
         shell: bash
         run: |
+          scoop config use_external_7zip true
           scoop install ninja binaryen
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
       - name: Extract TinyGo version
@@ -41,10 +40,10 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Restore cached LLVM source
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-source
         with:
           key: llvm-source-20-windows-v1
@@ -58,7 +57,7 @@ jobs:
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         run: make llvm-source
       - name: Save cached LLVM source
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-source.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-source.outputs.cache-primary-key }}
@@ -69,7 +68,7 @@ jobs:
             llvm-project/lld/include
             llvm-project/llvm/include
       - name: Restore cached LLVM build
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
           key: llvm-build-20-windows-v2
@@ -86,20 +85,21 @@ jobs:
           # Remove unnecessary object files (to reduce cache size).
           find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
       - name: Save cached LLVM build
-        uses: actions/cache/save@v4
+        uses: actions/cache/save@v5
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
         with:
           key: ${{ steps.cache-llvm-build.outputs.cache-primary-key }}
           path: llvm-build
       - name: Cache Go cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
-          key: go-cache-windows-v1-${{ hashFiles('go.mod') }}
+          key: go-cache-windows-v2-${{ hashFiles('go.mod') }}
           path: |
             C:/Users/runneradmin/AppData/Local/go-build
             C:/Users/runneradmin/go/pkg/mod
       - name: Install wasmtime
         run: |
+          scoop config use_external_7zip true
           scoop install wasmtime@29.0.1
       - name: make gen-device
         run: make -j3 gen-device
@@ -114,16 +114,11 @@ jobs:
         working-directory: build/release
         run: 7z -tzip a tinygo${{ steps.version.outputs.version }}.windows-amd64.zip tinygo
       - name: Publish release artifact
-        # Note: this release artifact is double-zipped, see:
-        # https://github.com/actions/upload-artifact/issues/39
-        # We can essentially pick one of these:
-        # - have a dobule-zipped artifact when downloaded from the UI
-        # - have a very slow artifact upload
-        # We're doing the former here, to keep artifact uploads fast.
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
-          name: windows-amd64-double-zipped-${{ steps.version.outputs.version }}
+          name: tinygo${{ steps.version.outputs.version }}.windows-amd64.zip
           path: build/release/tinygo${{ steps.version.outputs.version }}.windows-amd64.zip
+          archive: false
 
   smoke-test-windows:
     runs-on: windows-2022
@@ -136,28 +131,24 @@ jobs:
           maximum-size: 24GB
           disk-root: "C:"
       - uses: MinoruSekine/setup-scoop@v4
-        with:
-          scoop_update: 'false'
       - name: Install Dependencies
         shell: bash
         run: |
+          scoop config use_external_7zip true
           scoop install binaryen
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Download TinyGo build
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
         with:
-          name: windows-amd64-double-zipped-${{ needs.build-windows.outputs.version }}
+          name: tinygo${{ needs.build-windows.outputs.version }}.windows-amd64.zip
           path: build/
-      - name: Unzip TinyGo build
-        shell: bash
-        working-directory: build
-        run: 7z x tinygo*.windows-amd64.zip -r
+        # This build is already unzipped.
       - name: Smoke tests
         shell: bash
         run: make smoketest TINYGO=$(PWD)/build/tinygo/bin/tinygo
@@ -173,21 +164,18 @@ jobs:
           maximum-size: 24GB
           disk-root: "C:"
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Download TinyGo build
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
         with:
-          name: windows-amd64-double-zipped-${{ needs.build-windows.outputs.version }}
+          name: tinygo${{ needs.build-windows.outputs.version }}.windows-amd64.zip
           path: build/
-      - name: Unzip TinyGo build
-        shell: bash
-        working-directory: build
-        run: 7z x tinygo*.windows-amd64.zip -r
+        # This build is already unzipped.
       - name: Test stdlib packages
         run: make tinygo-test TINYGO=$(PWD)/build/tinygo/bin/tinygo
 
@@ -202,27 +190,23 @@ jobs:
           maximum-size: 24GB
           disk-root: "C:"
       - uses: MinoruSekine/setup-scoop@v4
-        with:
-          scoop_update: 'false'
       - name: Install Dependencies
         shell: bash
         run: |
-          scoop install binaryen && scoop install wasmtime@29.0.1
+          scoop config use_external_7zip true
+          scoop install binaryen wasmtime@29.0.1
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.26.2'
           cache: true
       - name: Download TinyGo build
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v8
         with:
-          name: windows-amd64-double-zipped-${{ needs.build-windows.outputs.version }}
+          name: tinygo${{ needs.build-windows.outputs.version }}.windows-amd64.zip
           path: build/
-      - name: Unzip TinyGo build
-        shell: bash
-        working-directory: build
-        run: 7z x tinygo*.windows-amd64.zip -r
+        # This build is already unzipped.
       - name: Test stdlib packages on wasip1
         run: make tinygo-test-wasip1-fast TINYGO=$(PWD)/build/tinygo/bin/tinygo

CHANGELOG.md

@@ -1,3 +1,160 @@
+0.41.1
+---
+* **machine**
+  - esp32c3: correct pin interrupt setup call that was overlooked from #5320
+* **runtime**
+  - esp32s3: wait for TIMG0 update register to clear before reading timer registers
+* **net**
+  - update net module to a version that is backwards compatible with Go 1.25.x to fix #5332
+
+0.41.0
+---
+* **general**
+  - go.mod, compiler: bump minimum Go version to 1.23
+  - builder: support Go 1.26 now
+  - feat: add inheritable-only field to filter processor-level targets (#5270)
+  - feature: add esp32flash flash method for esp32s3/esp32c3/esp32/esp8266
+  - flashing: introduce flash method 'esp32jtag' for esp32c3/esp32s3 targets
+  - fashing: add "adb" flash method using Android Debug Bridge
+  - main: auto-use best available flashing options on esp32
+  - espflasher: update to espflasher 0.6.0
+* **compiler**
+  - implement method-set based AssignableTo and Implements (#5304)
+  - simplify createObjectLayout
+  - implement copy directly
+  - fix min/max on floats by using intrinsics
+  - add element layout to sliceAppend
+  - add intrinsic for crypto/internal/constanttime.boolToUint8
+  - fix SyscallN handling for Windows on Go 1.26+
+* **core**
+  - reflect: add TypeAssert
+  - reflect: fix TypeAssert for structs
+  - sync: add WaitGroup.Go
+  - os: add UserCacheDir and UserConfigDir
+  - os: implement Lchown function for changing file ownership (#5161)
+  - testing: add b.ReportMetric()
+  - errors: add errors package to passing list
+  - internal/gclayout: use correct lengths
+  - internal/abi: add EscapeNonString, EscapeToResultNonString
+  - internal, runtime: add internal fips bool
+  - internal/itoa: resurrect from Go stdlib
+  - internal/syscall/unix: implement GetRandom for WASI targets
+  - interp: make ptrtoint size mismatch a recoverable error
+  - loader: support "all:" prefix in //go:embed patterns
+  - loader, crypto/internal/entropy: fix 32 MiB RAM overflow on microcontrollers
+  - loader, unicode/utf8: fix hiBits overflow on 16-bit AVR targets
+  - builder: order embedded files deterministically
+  - builder: fix panic in findPackagePath when using -size short
+  - builder: fix SIGSEGV when stripping duplicate function definitions
+  - builder, runtime: fix duplicate symbol error with Go 1.26+ on Windows
+  - builder: use target-specific -march for RISC-V library compilation
+  - transform: modify output format from the -print-allocs flag to match the go coverage tool format
+  - cgo: allow for changes to 'short-enums' flag
+  - wasm: add more stubbed file operations
+* **machine**
+  - esp32c3: implement BlockDevice for esp32c3 flash
+  - esp32c3: clear GPIO STATUS before dispatching pin callbacks
+  - esp32c3: implement USBDevice using interrupts
+  - esp32c3: add Enable stub for QEMU test target
+  - esp32c3: fix interrupt disable handling
+  - esp32c3: clear MCAUSE after handling interrupt
+  - esp32c3: map missing IRAM sections in linker script
+  - esp32c3: fix to use PROVIDE() for WiFi/BLE ROM function addresses to allow blob overrides
+  - esp32c3: add WiFi/BLE ROM linker support
+  - esp32c3: use TIMG0 alarm interrupt for sleepTicks instead of busy-waiting
+  - esp32s3: implement Pin.SetInterrupt for GPIO pin change interrupts
+  - esp32s3: use edge-triggered CPU interrupt for GPIO pin interrupts
+  - esp32s3: add interrupt support (#5244)
+  - esp32s3: switch USB implementation to use interrupts instead of polling
+  - esp32s3: replace inline ISR with full interrupt vector handler
+  - esp32s3: use TIMG0 alarm interrupt for sleepTicks
+  - esp32s3: improve exception handlers, add procPin/procUnpin, and linker wrap flags
+  - esp32s3: fix Xtensa register window spill using recursive call4 in task switching
+  - esp32s3: update linker script and boot assembly for multi-page flash XIP mapping
+  - esp32s3: add flash XIP boot assembly with cache/MMU init
+  - esp32s3: implement SPI (#5169)
+  - esp32s3: implement I2C interface (#5210)
+  - esp32s3: implement RNG based on onboard hardware random number generator
+  - esp32s3,esp32c3: add USB serial support
+  - esp32s3,esp32c3: add txStalled flag to skip USB serial spin when no host
+  - esp32s3,esp32c3: make USB Serial/JTAG writes non-blocking when FIFO is full
+  - esp32c3/esp32s3: refactor ADC implementation to reduce code duplication
+  - esp32s3,esp32c3: add ADC support (#5231)
+  - esp32s3,esp32c3: add PWM support (#5215)
+  - esp32c3/esp32s3: refactoring and corrections for SPI implementation
+  - esp32xx: add WASM simulator support for ESP32-C3/ESP32-S3 targets
+  - esp32: default SPI CS pin to NoPin when unset
+  - esp: fix tinygo_scanCurrentStack to spill register windows
+  - stm32: fix UART interrupt storm caused by uncleared overrun error
+  - stm32: fix PWM problem due to register shifting
+  - stm32: add STM32U585 target definition and runtime
+  - stm32: add STM32U5 GPIO, pin interrupts, and UART support
+  - stm32: add STM32U5 I2C support
+  - stm32: add STM32U5 SPI support
+  - stm32u585: implement ADC
+  - stm32g0b1: add support (#5150)
+  - stm32g0b1: add Watchdog + ADC support (#5158)
+  - stm32l0: add flash support
+  - stm32l0x1,l0x2: TIM: adapt to 32-bit register access
+  - stm32g0: sync with updated stm32 device files
+  - attiny85: add USI-based SPI support (#5181)
+  - attiny85: add PWM support (#5171)
+  - rp: add Close function to UART to allow for removing all system resources/power usage
+  - rp: use blockReset() and unresetBlockWait() helper functions for peripheral reset/unreset
+  - rp2: prevent PWM Period method overflow
+  - rp2: add per-byte timeout budget for I2C (#5189)
+  - feather-m0: export UART0 and pins
+  - usb/cdc: better ring buffer implementation (#5209)
+  - fix: replace ! with ~ for register mask
+  - atmega328p_simulator: add correct build tag for arduino_uno after renaming
+* **net**
+  - update to Go 1.26.2 net package with UDP and JS improvements
+* **runtime**
+  - implement fminimum/fmaximum
+  - make timeoffset atomic
+  - add MemStats.HeapObjects
+  - handle GODEBUG on wasip2 (#5312)
+  - fix Darwin syscall return value truncation and lost arguments
+  - add syscall.runtimeClearenv for Go 1.26
+  - split syscall functions for darwin changes for 1.26
+  - fix: init heap before random number seed on wasm platforms
+* **targets**
+  - add esp32s3-supermini board target
+  - add support for Seeedstudio Xiao-RP2350 board
+  - add Shrike Lite board (#5170)
+  - rename arduino target to arduino-uno
+  - add pins/setup for Arduino UNO Q board QWIIC connector
+  - correct pin mapping for Arduino UNO Q STM32 MCU
+  - add stm32u585 openocd commands for flashing on Arduino UNO Q
+  - correct name/tag use for esp32s3-wroom1 board
+  - modify esp32, esp32s3, esp32c3, & esp8266 targets to use built-in esp32flash
+  - switch rp2040/rp2350 to default to tasks scheduler
+  - change default stack size for esp32c3 and esp32s3 to 8196
+  - swan: rename group build tag stm32l4x5 => stm32l4y5 to avoid clash with stm32 device name
+  - nucleo-f722ze: add build-tag stm32f722
+  - fix: set stm32u5x clock rate to default
+  - create generic targets for esp32 boards
+* **libs**
+  - stm32-svd: update submodule
+  - update tools/gen-device-svd for recent changes to stm32-svd file structure (#5212)
+* **build/test**
+  - build: use Golang 1.26 for all builds
+  - build: actually use the version of llvm we are supposed to be testing by using brew link command
+  - build: let scoop run updates to resolve binaryen install failures on Windows
+  - ci: don't double zip release artifacts
+  - test: increase default timeout from 1 to 2 minutes to prevent spurious CI fails
+  - testdata: fix flaky timers test by draining ticker channel after Stop
+  - testdata: more corpus entries (#5182)
+  - add soypat/lneto to corpus
+  - GNUmakefile: add context and expvar to stdlib tests
+  - GNUmakefile: add encoding/xml to stdlib tests on Linux
+  - main (test): skip mipsle test if the emulator is missing
+  - make: remove machine without board from smoketest
+  - stm32: add Arduino UNO Q to smoketests
+  - flake: bump to nixpkgs 25.11
+  - chore: update all github actions to latest versions
+  - fix: use external 7zip for scoop installs on Windows
+
 0.40.1
 ---
 * **machine**

Dockerfile

@@ -1,5 +1,5 @@
 # tinygo-llvm stage obtains the llvm source for TinyGo
-FROM golang:1.25 AS tinygo-llvm
+FROM golang:1.26 AS tinygo-llvm
 
 RUN apt-get update && \
     apt-get install -y apt-utils make cmake clang-17 ninja-build && \
@@ -33,7 +33,7 @@ RUN cd /tinygo/ && \
 
 # tinygo-compiler copies the compiler build over to a base Go container (without
 # all the build tools etc).
-FROM golang:1.25 AS tinygo-compiler
+FROM golang:1.26 AS tinygo-compiler
 
 # Copy tinygo build.
 COPY --from=tinygo-compiler-build /tinygo/build/release/tinygo /tinygo

GNUmakefile

@@ -289,13 +289,13 @@ WASM_TOOLS_MODULE=go.bytecodealliance.org
 .PHONY: wasi-syscall
 wasi-syscall: wasi-cm
 	rm -rf ./src/internal/wasi/*
-	go run -modfile ./internal/wasm-tools/go.mod $(WASM_TOOLS_MODULE)/cmd/wit-bindgen-go generate --versioned -o ./src/internal -p internal --cm internal/cm ./lib/wasi-cli/wit
+	go run $(WASM_TOOLS_MODULE)/cmd/wit-bindgen-go generate --versioned -o ./src/internal -p internal --cm internal/cm ./lib/wasi-cli/wit
 
 # Copy package cm into src/internal/cm
 .PHONY: wasi-cm
 wasi-cm:
 	rm -rf ./src/internal/cm/*
-	rsync -rv --delete --exclude go.mod --exclude '*_test.go' --exclude '*_json.go' --exclude '*.md' --exclude LICENSE $(shell go list -modfile ./internal/wasm-tools/go.mod -m -f {{.Dir}} $(WASM_TOOLS_MODULE)/cm)/ ./src/internal/cm
+	rsync -rv --delete --exclude go.mod --exclude '*_test.go' --exclude '*_json.go' --exclude '*.md' --exclude LICENSE $(shell go list -m -f {{.Dir}} $(WASM_TOOLS_MODULE)/cm)/ ./src/internal/cm
 
 # Check for Node.js used during WASM tests.
 MIN_NODEJS_VERSION=18
@@ -339,14 +339,17 @@ TEST_PACKAGES_FAST = \
 	embed/internal/embedtest \
 	encoding \
 	encoding/ascii85 \
+	errors \
 	encoding/asn1 \
 	encoding/base32 \
 	encoding/base64 \
 	encoding/csv \
 	encoding/hex \
+	expvar \
 	go/ast \
 	go/format \
 	go/scanner \
+	go/token \
 	go/version \
 	hash \
 	hash/adler32 \
@@ -359,6 +362,7 @@ TEST_PACKAGES_FAST = \
 	math/cmplx \
 	net/http/internal/ascii \
 	net/mail \
+	net/url \
 	os \
 	path \
 	reflect \
@@ -379,6 +383,7 @@ TEST_PACKAGES_FAST = \
 # crypto/des fails on wasi, needs panic()/recover()
 # 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
+# encoding/xml takes a minute on linux and gives a stack overflow on wasi
 # image requires recover(), which is not yet supported on wasi
 # io/ioutil requires os.ReadDir, which is not yet supported on windows or wasi
 # mime: fail on wasi; neds panic()/recover()
@@ -396,11 +401,13 @@ TEST_PACKAGES_FAST = \
 TEST_PACKAGES_LINUX := \
 	archive/zip \
 	compress/flate \
+	context \
 	crypto/aes \
 	crypto/des \
 	crypto/hmac \
 	debug/dwarf \
 	debug/plan9obj \
+	encoding/xml \
 	image \
 	io/ioutil \
 	mime \
@@ -437,6 +444,7 @@ TEST_PACKAGES_NONWASM = \
 	crypto/ecdsa \
 	debug/macho \
 	embed/internal/embedtest \
+	expvar \
 	go/format \
 	os \
 	testing \
@@ -480,7 +488,7 @@ TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_WINDOWS)
 TEST_IOFS := false
 endif
 
-TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic'
+TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic|TestAsValidation'
 TEST_ADDITIONAL_FLAGS ?=
 
 # Test known-working standard library packages.
@@ -626,7 +634,7 @@ smoketest: testchdir
 	@$(MD5SUM) test.hex
 	# test simulated boards on play.tinygo.org
 ifneq ($(WASM), 0)
-	GOOS=js GOARCH=wasm $(TINYGO) build -size short -o test.wasm -tags=arduino              examples/blinky1
+	GOOS=js GOARCH=wasm $(TINYGO) build -size short -o test.wasm -tags=arduino_uno          examples/blinky1
 	@$(MD5SUM) test.wasm
 	GOOS=js GOARCH=wasm $(TINYGO) build -size short -o test.wasm -tags=hifive1b             examples/blinky1
 	@$(MD5SUM) test.wasm
@@ -644,6 +652,8 @@ ifneq ($(WASM), 0)
 	@$(MD5SUM) test.wasm
 	GOOS=js GOARCH=wasm $(TINYGO) build -size short -o test.wasm -tags=pico                 examples/blinky1
 	@$(MD5SUM) test.wasm
+	GOOS=js GOARCH=wasm $(TINYGO) build -size short -o test.wasm -tags=xiao_esp32s3         examples/blinky1
+	@$(MD5SUM) test.wasm
 endif
 	# test all targets/boards
 	$(TINYGO) build -size short -o test.hex -target=pca10040-s132v6     examples/blinky1
@@ -816,6 +826,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=vicharak_shrike-lite examples/echo
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=xiao-rp2350        examples/blinky1
+	@$(MD5SUM) test.hex
 	# test pwm
 	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
 	@$(MD5SUM) test.hex
@@ -875,18 +887,24 @@ ifneq ($(STM32), 0)
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=stm32l0x1           examples/serial
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino-uno-q       examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino-uno-q       examples/serial
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino-uno-q       examples/blinkm
+	@$(MD5SUM) test.hex
 endif
 	$(TINYGO) build -size short -o test.hex -target=atmega328pb         examples/blinkm
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=atmega1284p         examples/machinetest
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=arduino             examples/blinky1
+	$(TINYGO) build -size short -o test.hex -target=arduino-uno         examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=arduino-leonardo    examples/blinky1
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=arduino             examples/pwm
+	$(TINYGO) build -size short -o test.hex -target=arduino-uno         examples/pwm
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=arduino -scheduler=tasks  examples/blinky1
+	$(TINYGO) build -size short -o test.hex -target=arduino-uno -scheduler=tasks  examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=arduino-mega1280    examples/blinky1
 	@$(MD5SUM) test.hex
@@ -905,10 +923,18 @@ endif
 	$(TINYGO) build -size short -o test.hex -target=digispark -gc=leaking examples/blinky1
 	@$(MD5SUM) test.hex
 ifneq ($(XTENSA), 0)
+	$(TINYGO) build -size short -o test.bin -target=esp32-generic       examples/machinetest
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-generic     examples/machinetest
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32s3-generic     examples/machinetest
+	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=esp32-mini32      	examples/blinky1
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=esp32c3-supermini   examples/blinky1
 	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-supermini   examples/blinkm
+	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=nodemcu             examples/blinky1
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target m5stack-core2       examples/machinetest
@@ -921,13 +947,39 @@ ifneq ($(XTENSA), 0)
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target mch2022             examples/machinetest
 	@$(MD5SUM) test.bin
+	# xiao-esp32s3
 	$(TINYGO) build -size short -o test.bin -target=xiao-esp32s3   		examples/blinky1
 	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=xiao-esp32s3   		examples/blinkm
+	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=xiao-esp32s3   		examples/mcp3008
 	@$(MD5SUM) test.bin
-	$(TINYGO) build -size short -o test.bin -target=esp32s3-wroom1	    examples/mcp3008
+	$(TINYGO) build -size short -o test.bin -target=xiao-esp32s3   		examples/pwm
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=xiao-esp32s3   		examples/adc
+	@$(MD5SUM) test.bin
+	# esp32s3-supermini
+	$(TINYGO) build -size short -o test.bin -target=esp32s3-supermini	    examples/blinky1
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32s3-supermini	    examples/blinkm
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32s3-supermini	    examples/mcp3008
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32s3-supermini   	examples/adc
 	@$(MD5SUM) test.bin
 endif
+    # esp32c3-supermini
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-supermini	    examples/blinky1
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-supermini	    examples/blinkm
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-supermini	    examples/mcp3008
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-supermini   	examples/pwm
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-supermini   	examples/adc
+	@$(MD5SUM) test.bin
+
 	$(TINYGO) build -size short -o test.bin -target=esp-c3-32s-kit      examples/blinky1
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=qtpy-esp32c3        examples/machinetest
@@ -940,6 +992,7 @@ endif
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=esp32c3-12f         examples/blinky1
 	@$(MD5SUM) test.bin
+
 	$(TINYGO) build -size short -o test.bin -target=makerfabs-esp32c3spi35 examples/machinetest
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.hex -target=hifive1b            examples/blinky1
@@ -1133,7 +1186,7 @@ endif
 
 .PHONY: tools
 tools:
-	cd internal/tools && go generate -tags tools ./
+	go generate -tags tools ./
 
 LINTDIRS=src/os/ src/reflect/
 .PHONY: lint

README.md

@@ -34,10 +34,10 @@ func main() {
 }
 ```
 
-The above program can be compiled and run without modification on an Arduino Uno, an Adafruit ItsyBitsy M0, or any of the supported boards that have a built-in LED, just by setting the correct TinyGo compiler target. For example, this compiles and flashes an Arduino Uno:
+The above program can be compiled and run without modification on an [Arduino Uno](https://tinygo.org/docs/reference/microcontrollers/boards/arduino-uno), an [Adafruit Circuit Playground Express](https://tinygo.org/docs/reference/microcontrollers/featured/circuitplay-express), a [Seeed Studio XIAO-ESP32S3](https://tinygo.org/docs/reference/microcontrollers/featured/xiao-esp32s3) or any of the many supported boards that have a built-in LED, just by setting the correct TinyGo compiler target. For example, this compiles and flashes an Arduino Uno:
 
 ```shell
-tinygo flash -target arduino examples/blinky1
+tinygo flash -target arduino-uno examples/blinky1
 ```
 
 ## WebAssembly
@@ -77,7 +77,7 @@ See the [getting started instructions](https://tinygo.org/getting-started/) for
 
 ### Embedded
 
-You can compile TinyGo programs for over 94 different microcontroller boards.
+You can compile TinyGo programs for over 150 different microcontroller boards.
 
 For more information, please see https://tinygo.org/docs/reference/microcontrollers/
 
@@ -142,7 +142,7 @@ Non-goals:
 
 ## Why this project exists
 
-> We never expected Go to be an embedded language and so its got serious problems...
+> We never expected Go to be an embedded language, and so it’s got serious problems...
 
 -- Rob Pike, [GopherCon 2014 Opening Keynote](https://www.youtube.com/watch?v=VoS7DsT1rdM&feature=youtu.be&t=2799)
 

builder/build.go

@@ -546,6 +546,23 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 				if err != nil {
 					return fmt.Errorf("failed to load bitcode file: %w", err)
 				}
+				// Resolve duplicate function definitions before linking.
+				// This can happen when a newer Go version adds a function
+				// body in a standard library package that was previously
+				// just a declaration provided by //go:linkname from the
+				// runtime. In that case, keep the existing (runtime)
+				// definition by weakening the new one's linkage so the
+				// LLVM linker discards it in favor of the existing one.
+				for fn := pkgMod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+					if fn.IsDeclaration() {
+						continue
+					}
+					existing := mod.NamedFunction(fn.Name())
+					if existing.IsNil() || existing.IsDeclaration() {
+						continue
+					}
+					fn.SetLinkage(llvm.LinkOnceODRLinkage)
+				}
 				err = llvm.LinkModules(mod, pkgMod)
 				if err != nil {
 					return fmt.Errorf("failed to link module: %w", err)

builder/cc1as.h

@@ -107,7 +107,7 @@ struct AssemblerInvocation {
   EmitDwarfUnwindType EmitDwarfUnwind;
 
   // Whether to emit compact-unwind for non-canonical entries.
-  // Note: maybe overriden by other constraints.
+  // Note: maybe overridden by other constraints.
   LLVM_PREFERRED_TYPE(bool)
   unsigned EmitCompactUnwindNonCanonical : 1;
 

builder/config.go

@@ -26,7 +26,7 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 
 	// Version range supported by TinyGo.
 	const minorMin = 19
-	const minorMax = 25
+	const minorMax = 26
 
 	// Check that we support this Go toolchain version.
 	gorootMajor, gorootMinor, err := goenv.GetGorootVersion()

builder/library.go

@@ -167,9 +167,9 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 		// double.
 		args = append(args, "-mdouble=64")
 	case "riscv32":
-		args = append(args, "-march=rv32imac", "-fforce-enable-int128")
+		args = append(args, "-march="+riscvMarch(config, "rv32imac"), "-fforce-enable-int128")
 	case "riscv64":
-		args = append(args, "-march=rv64gc")
+		args = append(args, "-march="+riscvMarch(config, "rv64gc"))
 	case "mips":
 		args = append(args, "-fno-pic")
 	}
@@ -298,3 +298,17 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 		once.Do(unlock)
 	}, nil
 }
+
+// riscvMarch returns the -march value for RISC-V library compilation.
+// It extracts the value from the target's cflags if present, otherwise
+// falls back to the provided default. This ensures libraries are compiled
+// with the correct ISA extensions for each target (e.g. rv32imc for
+// ESP32-C3 which lacks the atomic extension).
+func riscvMarch(config *compileopts.Config, defaultMarch string) string {
+	for _, flag := range config.Target.CFlags {
+		if strings.HasPrefix(flag, "-march=") {
+			return flag[len("-march="):]
+		}
+	}
+	return defaultMarch
+}

builder/sizes.go

@@ -954,7 +954,11 @@ func findPackagePath(path string, packagePathMap map[string]string) (packagePath
 			libPath := strings.TrimPrefix(path, filepath.Join(goenv.Get("TINYGOROOT"), "lib")+string(os.PathSeparator))
 			parts := strings.SplitN(libPath, string(os.PathSeparator), 2)
 			packagePath = "C " + parts[0]
-			filename = parts[1]
+			if len(parts) > 1 {
+				filename = parts[1]
+			} else {
+				filename = parts[0]
+			}
 		} else if prefix := filepath.Join(goenv.Get("TINYGOROOT"), "llvm-project", "compiler-rt"); strings.HasPrefix(path, prefix) {
 			packagePath = "C compiler-rt"
 			filename = strings.TrimPrefix(path, prefix+string(os.PathSeparator))

builder/sizes_test.go

@@ -42,9 +42,9 @@ func TestBinarySize(t *testing.T) {
 	// This is a small number of very diverse targets that we want to test.
 	tests := []sizeTest{
 		// microcontrollers
-		{"hifive1b", "examples/echo", 3668, 280, 0, 2244},
+		{"hifive1b", "examples/echo", 3680, 280, 0, 2252},
 		{"microbit", "examples/serial", 2694, 342, 8, 2248},
-		{"wioterminal", "examples/pininterrupt", 6837, 1491, 120, 6888},
+		{"wioterminal", "examples/pininterrupt", 7074, 1510, 120, 7248},
 
 		// TODO: also check wasm. Right now this is difficult, because
 		// wasm binaries are run through wasm-opt and therefore the

cgo/security.go

@@ -78,6 +78,7 @@ var validCompilerFlags = []*regexp.Regexp{
 	re(`-f(no-)?(pic|PIC|pie|PIE)`),
 	re(`-f(no-)?plt`),
 	re(`-f(no-)?rtti`),
+	re(`-f(no-)?short-enums`),
 	re(`-f(no-)?split-stack`),
 	re(`-f(no-)?stack-(.+)`),
 	re(`-f(no-)?strict-aliasing`),

compileopts/config.go

@@ -536,7 +536,7 @@ func (c *Config) Programmer() (method, openocdInterface string) {
 	case "":
 		// No configuration supplied.
 		return c.Target.FlashMethod, c.Target.OpenOCDInterface
-	case "openocd", "msd", "command":
+	case "openocd", "msd", "command", "adb":
 		// The -programmer flag only specifies the flash method.
 		return c.Options.Programmer, c.Target.OpenOCDInterface
 	case "bmp":

compileopts/target.go

@@ -24,6 +24,7 @@ import (
 // https://github.com/shepmaster/rust-arduino-blink-led-no-core-with-cargo/blob/master/blink/arduino.json
 type TargetSpec struct {
 	Inherits         []string `json:"inherits,omitempty"`
+	InheritableOnly  bool     `json:"inheritable-only"` // this target is only meant to be inherited from, not used directly
 	Triple           string   `json:"llvm-target,omitempty"`
 	CPU              string   `json:"cpu,omitempty"`
 	ABI              string   `json:"target-abi,omitempty"` // roughly equivalent to -mabi= flag
@@ -63,6 +64,9 @@ type TargetSpec struct {
 	OpenOCDCommands  []string `json:"openocd-commands,omitempty"`
 	OpenOCDVerify    *bool    `json:"openocd-verify,omitempty"` // enable verify when flashing with openocd
 	JLinkDevice      string   `json:"jlink-device,omitempty"`
+	ADBPreCommands   []string `json:"adb-pre-commands,omitempty"`
+	ADBPushRemote    string   `json:"adb-push-remote,omitempty"`
+	ADBPostCommands  []string `json:"adb-post-commands,omitempty"`
 	CodeModel        string   `json:"code-model,omitempty"`
 	RelocationModel  string   `json:"relocation-model,omitempty"`
 	WITPackage       string   `json:"wit-package,omitempty"`
@@ -148,6 +152,11 @@ func (spec *TargetSpec) loadFromGivenStr(str string) error {
 
 // resolveInherits loads inherited targets, recursively.
 func (spec *TargetSpec) resolveInherits() error {
+	// Save InheritableOnly before resolving, since it must not propagate
+	// from parent to child (a board target should not become inheritable-only
+	// just because its parent processor target is).
+	inheritableOnly := spec.InheritableOnly
+
 	// First create a new spec with all the inherited properties.
 	newSpec := &TargetSpec{}
 	for _, name := range spec.Inherits {
@@ -173,6 +182,9 @@ func (spec *TargetSpec) resolveInherits() error {
 	}
 	*spec = *newSpec
 
+	// Restore InheritableOnly from the original spec, not from parents.
+	spec.InheritableOnly = inheritableOnly
+
 	return nil
 }
 
@@ -239,10 +251,17 @@ func GetTargetSpecs() (map[string]*TargetSpec, error) {
 			continue
 		}
 		path := filepath.Join(dir, entry.Name())
+
 		spec, err := LoadTarget(&Options{Target: path})
 		if err != nil {
 			return nil, fmt.Errorf("could not list target: %w", err)
 		}
+
+		if spec.InheritableOnly {
+			// Skip targets that are only meant to be inherited from, not used directly.
+			continue
+		}
+
 		if spec.FlashMethod == "" && spec.FlashCommand == "" && spec.Emulator == "" {
 			// This doesn't look like a regular target file, but rather like
 			// a parent target (such as targets/cortex-m.json).

compileopts/target_test.go

@@ -23,6 +23,37 @@ func TestLoadTarget(t *testing.T) {
 	}
 }
 
+func TestGetTargetSpecs_InheritableOnlyTargetsExcluded(t *testing.T) {
+	specs, err := GetTargetSpecs()
+	if err != nil {
+		t.Fatal("GetTargetSpecs failed:", err)
+	}
+
+	// Inheritable-only processor-level targets should not appear in the listing.
+	inheritableOnlyTargets := []string{"esp32", "esp32c3", "esp32s3", "esp8266", "rp2040", "rp2350", "rp2350b"}
+	for _, name := range inheritableOnlyTargets {
+		if _, ok := specs[name]; ok {
+			t.Errorf("inheritable-only target %q should not appear in GetTargetSpecs", name)
+		}
+	}
+
+	// Board targets that inherit from inheritable-only targets should still appear.
+	boardTargets := []string{"esp32-coreboard-v2", "pico"}
+	for _, name := range boardTargets {
+		if _, ok := specs[name]; !ok {
+			t.Errorf("board target %q should appear in GetTargetSpecs", name)
+		}
+	}
+}
+
+func TestLoadTarget_InheritableOnlyTargetStillLoadable(t *testing.T) {
+	// Inheritable-only targets should still be loadable directly (for building).
+	_, err := LoadTarget(&Options{Target: "esp32"})
+	if err != nil {
+		t.Errorf("LoadTarget should still load inheritable-only target esp32: %v", err)
+	}
+}
+
 func TestOverrideProperties(t *testing.T) {
 	baseAutoStackSize := true
 	base := &TargetSpec{

compiler/compiler.go

@@ -873,6 +873,10 @@ func (c *compilerContext) createPackage(irbuilder llvm.Builder, pkg *ssa.Package
 				// with a LLVM intrinsic.
 				continue
 			}
+			if ok := b.defineCryptoIntrinsic(); ok {
+				// Body of this function was replaced
+				continue
+			}
 			if member.Blocks == nil {
 				// Try to define this as an intrinsic function.
 				b.defineIntrinsicFunction()
@@ -1976,10 +1980,14 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 			return b.emitSV64Call(instr.Args, getPos(instr))
 		case strings.HasPrefix(name, "(device/riscv.CSR)."):
 			return b.emitCSROperation(instr)
-		case strings.HasPrefix(name, "syscall.Syscall") || strings.HasPrefix(name, "syscall.RawSyscall") || strings.HasPrefix(name, "golang.org/x/sys/unix.Syscall") || strings.HasPrefix(name, "golang.org/x/sys/unix.RawSyscall"):
+		case (strings.HasPrefix(name, "syscall.Syscall") || strings.HasPrefix(name, "syscall.RawSyscall") || strings.HasPrefix(name, "golang.org/x/sys/unix.Syscall") || strings.HasPrefix(name, "golang.org/x/sys/unix.RawSyscall")) && name != "syscall.SyscallN":
 			if b.GOOS != "darwin" {
 				return b.createSyscall(instr)
 			}
+		case name == "syscall.syscalln":
+			if b.GOOS == "windows" {
+				return b.createSyscalln(instr)
+			}
 		case strings.HasPrefix(name, "syscall.rawSyscallNoError") || strings.HasPrefix(name, "golang.org/x/sys/unix.RawSyscallNoError"):
 			return b.createRawSyscallNoError(instr)
 		case name == "runtime.supportsRecover":

compiler/interface.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"go/token"
 	"go/types"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -17,6 +18,12 @@ import (
 	"tinygo.org/x/go-llvm"
 )
 
+// numMethodHasMethodSet is a flag in bit 15 of the numMethod field (uint16) in
+// Named, Pointer, and Struct type descriptors. When set, an inline method set
+// is present in the type descriptor. Must match the constant in
+// src/internal/reflectlite/type.go.
+const numMethodHasMethodSet = 0x8000
+
 // Type kinds for basic types.
 // They must match the constants for the Kind type in src/reflect/type.go.
 var basicTypes = [...]uint8{
@@ -183,6 +190,16 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 		typeFieldTypes := []*types.Var{
 			types.NewVar(token.NoPos, nil, "kind", types.Typ[types.Int8]),
 		}
+		// Compute the method set value for types that support methods.
+		var methods []*types.Func
+		for i := 0; i < ms.Len(); i++ {
+			methods = append(methods, ms.At(i).Obj().(*types.Func))
+		}
+		methodSetType := types.NewStruct([]*types.Var{
+			types.NewVar(token.NoPos, nil, "length", types.Typ[types.Uintptr]),
+			types.NewVar(token.NoPos, nil, "methods", types.NewArray(types.Typ[types.UnsafePointer], int64(len(methods)))),
+		}, nil)
+		methodSetValue := c.getMethodSetValue(methods)
 		switch typ := typ.(type) {
 		case *types.Basic:
 			typeFieldTypes = append(typeFieldTypes,
@@ -199,6 +216,13 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				types.NewVar(token.NoPos, nil, "ptrTo", types.Typ[types.UnsafePointer]),
 				types.NewVar(token.NoPos, nil, "underlying", types.Typ[types.UnsafePointer]),
 				types.NewVar(token.NoPos, nil, "pkgpath", types.Typ[types.UnsafePointer]),
+			)
+			if len(methods) > 0 {
+				typeFieldTypes = append(typeFieldTypes,
+					types.NewVar(token.NoPos, nil, "methods", methodSetType),
+				)
+			}
+			typeFieldTypes = append(typeFieldTypes,
 				types.NewVar(token.NoPos, nil, "name", types.NewArray(types.Typ[types.Int8], int64(len(pkgname)+1+len(name)+1))),
 			)
 		case *types.Chan:
@@ -218,6 +242,11 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				types.NewVar(token.NoPos, nil, "numMethods", types.Typ[types.Uint16]),
 				types.NewVar(token.NoPos, nil, "elementType", types.Typ[types.UnsafePointer]),
 			)
+			if len(methods) > 0 {
+				typeFieldTypes = append(typeFieldTypes,
+					types.NewVar(token.NoPos, nil, "methods", methodSetType),
+				)
+			}
 		case *types.Array:
 			typeFieldTypes = append(typeFieldTypes,
 				types.NewVar(token.NoPos, nil, "numMethods", types.Typ[types.Uint16]),
@@ -242,11 +271,16 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				types.NewVar(token.NoPos, nil, "numFields", types.Typ[types.Uint16]),
 				types.NewVar(token.NoPos, nil, "fields", types.NewArray(c.getRuntimeType("structField"), int64(typ.NumFields()))),
 			)
+			if len(methods) > 0 {
+				typeFieldTypes = append(typeFieldTypes,
+					types.NewVar(token.NoPos, nil, "methods", methodSetType),
+				)
+			}
 		case *types.Interface:
 			typeFieldTypes = append(typeFieldTypes,
 				types.NewVar(token.NoPos, nil, "ptrTo", types.Typ[types.UnsafePointer]),
+				types.NewVar(token.NoPos, nil, "methods", methodSetType),
 			)
-			// TODO: methods
 		case *types.Signature:
 			typeFieldTypes = append(typeFieldTypes,
 				types.NewVar(token.NoPos, nil, "ptrTo", types.Typ[types.UnsafePointer]),
@@ -292,14 +326,24 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				pkgname = pkg.Name()
 			}
 			pkgPathPtr := c.pkgPathPtr(pkgpath)
-			typeFields = []llvm.Value{
-				llvm.ConstInt(c.ctx.Int16Type(), uint64(numMethods), false), // numMethods
-				c.getTypeCode(types.NewPointer(typ)),                        // ptrTo
-				c.getTypeCode(typ.Underlying()),                             // underlying
-				pkgPathPtr,                                                  // pkgpath pointer
-				c.ctx.ConstString(pkgname+"."+name+"\x00", false),           // name
+			namedNumMethods := uint64(numMethods)
+			if namedNumMethods&numMethodHasMethodSet != 0 {
+				panic("numMethods overflow: too many exported methods on named type " + name)
 			}
-			metabyte |= 1 << 5 // "named" flag
+			if len(methods) > 0 {
+				namedNumMethods |= numMethodHasMethodSet
+			}
+			typeFields = []llvm.Value{
+				llvm.ConstInt(c.ctx.Int16Type(), namedNumMethods, false), // numMethods
+				c.getTypeCode(types.NewPointer(typ)),                     // ptrTo
+				c.getTypeCode(typ.Underlying()),                          // underlying
+				pkgPathPtr,                                               // pkgpath pointer
+			}
+			if len(methods) > 0 {
+				typeFields = append(typeFields, methodSetValue) // methods
+			}
+			typeFields = append(typeFields, c.ctx.ConstString(pkgname+"."+name+"\x00", false)) // name
+			metabyte |= 1 << 5                                                                 // "named" flag
 		case *types.Chan:
 			var dir reflectChanDir
 			switch typ.Dir() {
@@ -323,10 +367,20 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				c.getTypeCode(typ.Elem()),                  // elementType
 			}
 		case *types.Pointer:
+			ptrNumMethods := uint64(numMethods)
+			if ptrNumMethods&numMethodHasMethodSet != 0 {
+				panic("numMethods overflow: too many exported methods on pointer type")
+			}
+			if len(methods) > 0 {
+				ptrNumMethods |= numMethodHasMethodSet
+			}
 			typeFields = []llvm.Value{
-				llvm.ConstInt(c.ctx.Int16Type(), uint64(numMethods), false), // numMethods
+				llvm.ConstInt(c.ctx.Int16Type(), ptrNumMethods, false), // numMethods
 				c.getTypeCode(typ.Elem()),
 			}
+			if len(methods) > 0 {
+				typeFields = append(typeFields, methodSetValue)
+			}
 		case *types.Array:
 			typeFields = []llvm.Value{
 				llvm.ConstInt(c.ctx.Int16Type(), 0, false),             // numMethods
@@ -353,9 +407,16 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 
 			llvmStructType := c.getLLVMType(typ)
 			size := c.targetData.TypeStoreSize(llvmStructType)
+			structNumMethods := uint64(numMethods)
+			if structNumMethods&numMethodHasMethodSet != 0 {
+				panic("numMethods overflow: too many exported methods on struct type")
+			}
+			if len(methods) > 0 {
+				structNumMethods |= numMethodHasMethodSet
+			}
 			typeFields = []llvm.Value{
-				llvm.ConstInt(c.ctx.Int16Type(), uint64(numMethods), false), // numMethods
-				c.getTypeCode(types.NewPointer(typ)),                        // ptrTo
+				llvm.ConstInt(c.ctx.Int16Type(), structNumMethods, false), // numMethods
+				c.getTypeCode(types.NewPointer(typ)),                      // ptrTo
 				pkgPathPtr,
 				llvm.ConstInt(c.ctx.Int32Type(), uint64(size), false),            // size
 				llvm.ConstInt(c.ctx.Int16Type(), uint64(typ.NumFields()), false), // numFields
@@ -407,9 +468,14 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				}))
 			}
 			typeFields = append(typeFields, llvm.ConstArray(structFieldType, fields))
+			if len(methods) > 0 {
+				typeFields = append(typeFields, methodSetValue)
+			}
 		case *types.Interface:
-			typeFields = []llvm.Value{c.getTypeCode(types.NewPointer(typ))}
-			// TODO: methods
+			typeFields = []llvm.Value{
+				c.getTypeCode(types.NewPointer(typ)),
+				methodSetValue,
+			}
 		case *types.Signature:
 			typeFields = []llvm.Value{c.getTypeCode(types.NewPointer(typ))}
 			// TODO: params, return values, etc
@@ -696,17 +762,11 @@ func (b *builder) createTypeAssert(expr *ssa.TypeAssert) llvm.Value {
 			// This type assertion always succeeds, so we can just set commaOk to true.
 			commaOk = llvm.ConstInt(b.ctx.Int1Type(), 1, true)
 		} else {
-			// Type assert on interface type with methods.
-			// This is a call to an interface type assert function.
-			// The interface lowering pass will define this function by filling it
-			// with a type switch over all concrete types that implement this
-			// interface, and returning whether it's one of the matched types.
-			// This is very different from how interface asserts are implemented in
-			// the main Go compiler, where the runtime checks whether the type
-			// implements each method of the interface. See:
-			// https://research.swtch.com/interfaces
-			fn := b.getInterfaceImplementsFunc(expr.AssertedType)
-			commaOk = b.CreateCall(fn.GlobalValueType(), fn, []llvm.Value{actualTypeNum}, "")
+			// Type assert on an interface type with methods.
+			// Create a call to a declared-but-not-defined function that will
+			// be lowered by the interface lowering pass into a type-ID
+			// comparison chain.
+			commaOk = b.createInterfaceTypeAssert(intf, actualTypeNum)
 		}
 	} else {
 		name, _ := getTypeCodeName(expr.AssertedType)
@@ -783,20 +843,58 @@ func (c *compilerContext) getMethodsString(itf *types.Interface) string {
 	return strings.Join(methods, "; ")
 }
 
-// getInterfaceImplementsFunc returns a declared function that works as a type
-// switch. The interface lowering pass will define this function.
-func (c *compilerContext) getInterfaceImplementsFunc(assertedType types.Type) llvm.Value {
-	s, _ := getTypeCodeName(assertedType.Underlying())
-	fnName := s + ".$typeassert"
-	llvmFn := c.mod.NamedFunction(fnName)
-	if llvmFn.IsNil() {
-		llvmFnType := llvm.FunctionType(c.ctx.Int1Type(), []llvm.Type{c.dataPtrType}, false)
-		llvmFn = llvm.AddFunction(c.mod, fnName, llvmFnType)
-		c.addStandardDeclaredAttributes(llvmFn)
-		methods := c.getMethodsString(assertedType.Underlying().(*types.Interface))
-		llvmFn.AddFunctionAttr(c.ctx.CreateStringAttribute("tinygo-methods", methods))
+// getMethodSetValue creates the method set struct value for a list of methods.
+// The struct contains a length and a sorted array of method signature pointers.
+func (c *compilerContext) getMethodSetValue(methods []*types.Func) llvm.Value {
+	// Create a sorted list of method signature global names.
+	type methodRef struct {
+		name  string
+		value llvm.Value
 	}
-	return llvmFn
+	var refs []methodRef
+	for _, method := range methods {
+		name := method.Name()
+		if !token.IsExported(name) {
+			name = method.Pkg().Path() + "." + name
+		}
+		s, _ := getTypeCodeName(method.Type())
+		globalName := "reflect/types.signature:" + name + ":" + s
+		value := c.mod.NamedGlobal(globalName)
+		if value.IsNil() {
+			value = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), globalName)
+			value.SetInitializer(llvm.ConstNull(c.ctx.Int8Type()))
+			value.SetGlobalConstant(true)
+			value.SetLinkage(llvm.LinkOnceODRLinkage)
+			value.SetAlignment(1)
+			if c.Debug {
+				file := c.getDIFile("<Go type>")
+				diglobal := c.dibuilder.CreateGlobalVariableExpression(file, llvm.DIGlobalVariableExpression{
+					Name:        globalName,
+					File:        file,
+					Line:        1,
+					Type:        c.getDIType(types.Typ[types.Uint8]),
+					LocalToUnit: false,
+					Expr:        c.dibuilder.CreateExpression(nil),
+					AlignInBits: 8,
+				})
+				value.AddMetadata(0, diglobal)
+			}
+		}
+		refs = append(refs, methodRef{globalName, value})
+	}
+	sort.Slice(refs, func(i, j int) bool {
+		return refs[i].name < refs[j].name
+	})
+
+	var values []llvm.Value
+	for _, ref := range refs {
+		values = append(values, ref.value)
+	}
+
+	return c.ctx.ConstStruct([]llvm.Value{
+		llvm.ConstInt(c.uintptrType, uint64(len(values)), false),
+		llvm.ConstArray(c.dataPtrType, values),
+	}, false)
 }
 
 // getInvokeFunction returns the thunk to call the given interface method. The
@@ -823,6 +921,24 @@ func (c *compilerContext) getInvokeFunction(instr *ssa.CallCommon) llvm.Value {
 	return llvmFn
 }
 
+// createInterfaceTypeAssert creates a call to a declared-but-not-defined
+// $typeassert function for the given interface. This function will be defined
+// by the interface lowering pass as a type-ID comparison chain, avoiding the
+// need for runtime.typeImplementsMethodSet at compile time.
+func (b *builder) createInterfaceTypeAssert(intf *types.Interface, actualType llvm.Value) llvm.Value {
+	s, _ := getTypeCodeName(intf)
+	fnName := s + ".$typeassert"
+	llvmFn := b.mod.NamedFunction(fnName)
+	if llvmFn.IsNil() {
+		llvmFnType := llvm.FunctionType(b.ctx.Int1Type(), []llvm.Type{b.dataPtrType}, false)
+		llvmFn = llvm.AddFunction(b.mod, fnName, llvmFnType)
+		b.addStandardDeclaredAttributes(llvmFn)
+		methods := b.getMethodsString(intf)
+		llvmFn.AddFunctionAttr(b.ctx.CreateStringAttribute("tinygo-methods", methods))
+	}
+	return b.CreateCall(llvmFn.GlobalValueType(), llvmFn, []llvm.Value{actualType}, "")
+}
+
 // getInterfaceInvokeWrapper returns a wrapper for the given method so it can be
 // invoked from an interface. The wrapper takes in a pointer to the underlying
 // value, dereferences or unpacks it if necessary, and calls the real method.

compiler/intrinsics.go

@@ -208,6 +208,23 @@ func (b *builder) defineMathOp() {
 	b.CreateRet(result)
 }
 
+func (b *builder) defineCryptoIntrinsic() bool {
+	if b.fn.Pkg.Pkg.Path() != "crypto/internal/constanttime" {
+		return false
+	}
+
+	switch b.fn.Name() {
+	case "boolToUint8":
+		b.createFunctionStart(true)
+		param := b.getValue(b.fn.Params[0], b.fn.Pos())
+		result := b.CreateZExt(param, b.ctx.Int8Type(), "")
+		b.CreateRet(result)
+		return true
+	}
+
+	return false
+}
+
 // Implement most math/bits functions.
 //
 // This implements all the functions that operate on bits. It does not yet

compiler/symbol.go

@@ -540,7 +540,7 @@ func (c *compilerContext) isValidWasmType(typ types.Type, site wasmSite) bool {
 		}
 		for i := 0; i < typ.NumFields(); i++ {
 			ftyp := typ.Field(i).Type()
-			if ftyp.String() == "structs.HostLayout" {
+			if types.Unalias(ftyp).String() == "structs.HostLayout" {
 				hasHostLayout = true
 				continue
 			}

compiler/syscall.go

@@ -349,6 +349,130 @@ func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 	}
 }
 
+// createSyscalln emits instructions for the syscall.syscalln function on
+// Windows. This handles the variadic calling convention used in Go 1.26+:
+//
+//	func syscalln(fn, n uintptr, args ...uintptr) (r1, r2 uintptr, err Errno)
+//
+// The function generates a switch on n to dispatch to the correct fixed-argument
+// function pointer call with SetLastError(0)/GetLastError() wrapping.
+func (b *builder) createSyscalln(call *ssa.CallCommon) (llvm.Value, error) {
+	const maxArgs = 18 // Windows syscalls support up to 18 args
+
+	isI386 := strings.HasPrefix(b.Triple, "i386-")
+
+	// Get the function pointer (call.Args[0]) and n (call.Args[1]).
+	fn := b.getValue(call.Args[0], getPos(call))
+	fnPtr := b.CreateIntToPtr(fn, b.dataPtrType, "")
+	n := b.getValue(call.Args[1], getPos(call))
+
+	// Get the variadic args slice (call.Args[2]).
+	// In SSA, the variadic slice is the third argument.
+	var argsPtr llvm.Value
+	if len(call.Args) > 2 {
+		argsSlice := b.getValue(call.Args[2], getPos(call))
+		argsPtr = b.CreateExtractValue(argsSlice, 0, "args.data")
+	} else {
+		argsPtr = llvm.ConstNull(b.dataPtrType)
+	}
+
+	// Prepare SetLastError and GetLastError.
+	setLastError := b.mod.NamedFunction("SetLastError")
+	if setLastError.IsNil() {
+		llvmType := llvm.FunctionType(b.ctx.VoidType(), []llvm.Type{b.ctx.Int32Type()}, false)
+		setLastError = llvm.AddFunction(b.mod, "SetLastError", llvmType)
+		if isI386 {
+			setLastError.SetFunctionCallConv(llvm.X86StdcallCallConv)
+		}
+	}
+	getLastError := b.mod.NamedFunction("GetLastError")
+	if getLastError.IsNil() {
+		llvmType := llvm.FunctionType(b.ctx.Int32Type(), nil, false)
+		getLastError = llvm.AddFunction(b.mod, "GetLastError", llvmType)
+		if isI386 {
+			getLastError.SetFunctionCallConv(llvm.X86StdcallCallConv)
+		}
+	}
+
+	retType := b.ctx.StructType([]llvm.Type{b.uintptrType, b.uintptrType, b.uintptrType}, false)
+
+	// Create the merge block where all cases converge.
+	mergeBB := b.insertBasicBlock("syscalln.merge")
+
+	// Create the default (panic) block.
+	panicBB := b.insertBasicBlock("syscalln.panic")
+
+	// Create the switch on n.
+	sw := b.CreateSwitch(n, panicBB, maxArgs+1)
+
+	// We'll collect blocks and values for the PHI node.
+	var incomingVals []llvm.Value
+	var incomingBlocks []llvm.BasicBlock
+
+	// Generate a case for each arg count 0..maxArgs.
+	for i := 0; i <= maxArgs; i++ {
+		caseBB := b.insertBasicBlock("syscalln.case" + strconv.Itoa(i))
+		sw.AddCase(llvm.ConstInt(b.uintptrType, uint64(i), false), caseBB)
+		b.SetInsertPointAtEnd(caseBB)
+
+		// Load args[0] through args[i-1] from the slice data pointer.
+		var params []llvm.Value
+		var paramTypes []llvm.Type
+		for j := 0; j < i; j++ {
+			gep := b.CreateInBoundsGEP(b.uintptrType, argsPtr, []llvm.Value{
+				llvm.ConstInt(b.ctx.Int32Type(), uint64(j), false),
+			}, "")
+			arg := b.CreateLoad(b.uintptrType, gep, "")
+			params = append(params, arg)
+			paramTypes = append(paramTypes, b.uintptrType)
+		}
+
+		// SetLastError(0)
+		setCall := b.CreateCall(setLastError.GlobalValueType(), setLastError, []llvm.Value{llvm.ConstNull(b.ctx.Int32Type())}, "")
+		var sp llvm.Value
+		if isI386 {
+			setCall.SetInstructionCallConv(llvm.X86StdcallCallConv)
+			sp = b.readStackPointer()
+		}
+
+		// Call fn(args...)
+		fnType := llvm.FunctionType(b.uintptrType, paramTypes, false)
+		syscallResult := b.CreateCall(fnType, fnPtr, params, "")
+		if isI386 {
+			syscallResult.SetInstructionCallConv(llvm.X86StdcallCallConv)
+			b.writeStackPointer(sp)
+		}
+
+		// err = GetLastError()
+		errResult := b.CreateCall(getLastError.GlobalValueType(), getLastError, nil, "err")
+		if isI386 {
+			errResult.SetInstructionCallConv(llvm.X86StdcallCallConv)
+		}
+		if b.uintptrType != b.ctx.Int32Type() {
+			errResult = b.CreateZExt(errResult, b.uintptrType, "err.uintptr")
+		}
+
+		// Build {r1, 0, err}
+		result := llvm.ConstNull(retType)
+		result = b.CreateInsertValue(result, syscallResult, 0, "")
+		result = b.CreateInsertValue(result, errResult, 2, "")
+
+		incomingVals = append(incomingVals, result)
+		incomingBlocks = append(incomingBlocks, b.Builder.GetInsertBlock())
+		b.CreateBr(mergeBB)
+	}
+
+	// Panic block for n > maxArgs.
+	b.SetInsertPointAtEnd(panicBB)
+	b.CreateUnreachable()
+
+	// Merge block: PHI node to select the result.
+	b.SetInsertPointAtEnd(mergeBB)
+	phi := b.CreatePHI(retType, "syscalln.result")
+	phi.AddIncoming(incomingVals, incomingBlocks)
+	return phi, nil
+}
+
 // createRawSyscallNoError emits instructions for the Linux-specific
 // syscall.rawSyscallNoError function.
 func (b *builder) createRawSyscallNoError(call *ssa.CallCommon) (llvm.Value, error) {

compiler/testdata/interface.ll

@@ -9,12 +9,14 @@ target triple = "wasm32-unknown-wasi"
 @"reflect/types.type:basic:int" = linkonce_odr constant { i8, ptr } { i8 -62, ptr @"reflect/types.type:pointer:basic:int" }, align 4
 @"reflect/types.type:pointer:basic:int" = linkonce_odr constant { i8, i16, ptr } { i8 -43, i16 0, ptr @"reflect/types.type:basic:int" }, align 4
 @"reflect/types.type:pointer:named:error" = linkonce_odr constant { i8, i16, ptr } { i8 -43, i16 0, ptr @"reflect/types.type:named:error" }, align 4
-@"reflect/types.type:named:error" = linkonce_odr constant { i8, i16, ptr, ptr, ptr, [7 x i8] } { i8 116, i16 1, ptr @"reflect/types.type:pointer:named:error", ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}", ptr @"reflect/types.type.pkgpath.empty", [7 x i8] c".error\00" }, align 4
+@"reflect/types.signature:Error:func:{}{basic:string}" = linkonce_odr constant i8 0, align 1
+@"reflect/types.type:named:error" = linkonce_odr constant { i8, i16, ptr, ptr, ptr, { i32, [1 x ptr] }, [7 x i8] } { i8 116, i16 -32767, ptr @"reflect/types.type:pointer:named:error", ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}", ptr @"reflect/types.type.pkgpath.empty", { i32, [1 x ptr] } { i32 1, [1 x ptr] [ptr @"reflect/types.signature:Error:func:{}{basic:string}"] }, [7 x i8] c".error\00" }, align 4
 @"reflect/types.type.pkgpath.empty" = linkonce_odr unnamed_addr constant [1 x i8] zeroinitializer, align 1
-@"reflect/types.type:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr } { i8 84, ptr @"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" }, align 4
+@"reflect/types.type:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr, { i32, [1 x ptr] } } { i8 84, ptr @"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}", { i32, [1 x ptr] } { i32 1, [1 x ptr] [ptr @"reflect/types.signature:Error:func:{}{basic:string}"] } }, align 4
 @"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant { i8, i16, ptr } { i8 -43, i16 0, ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}" }, align 4
 @"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" = linkonce_odr constant { i8, i16, ptr } { i8 -43, i16 0, ptr @"reflect/types.type:interface:{String:func:{}{basic:string}}" }, align 4
-@"reflect/types.type:interface:{String:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr } { i8 84, ptr @"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" }, align 4
+@"reflect/types.signature:String:func:{}{basic:string}" = linkonce_odr constant i8 0, align 1
+@"reflect/types.type:interface:{String:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr, { i32, [1 x ptr] } } { i8 84, ptr @"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}", { i32, [1 x ptr] } { i32 1, [1 x ptr] [ptr @"reflect/types.signature:String:func:{}{basic:string}"] } }, align 4
 @"reflect/types.typeid:basic:int" = external constant i8
 
 ; Function Attrs: allockind("alloc,zeroed") allocsize(0)

go.mod

@@ -1,29 +1,53 @@
 module github.com/tinygo-org/tinygo
 
-go 1.22.0
+go 1.23.0
 
 require (
 	github.com/aykevl/go-wasm v0.0.2-0.20250317121156-42b86c494139
 	github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2
 	github.com/gofrs/flock v0.8.1
+	github.com/golangci/misspell v0.6.0
 	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 v0.1.13
 	github.com/mattn/go-tty v0.0.4
+	github.com/mgechev/revive v1.3.9
 	github.com/sigurn/crc16 v0.0.0-20211026045750-20ab5afb07e3
-	github.com/tetratelabs/wazero v1.6.0
-	go.bug.st/serial v1.6.0
+	github.com/tetratelabs/wazero v1.9.0
+	go.bug.st/serial v1.6.4
+	go.bytecodealliance.org v0.6.2
+	go.bytecodealliance.org/cm v0.2.2
 	golang.org/x/net v0.35.0
 	golang.org/x/sys v0.30.0
 	golang.org/x/tools v0.30.0
 	gopkg.in/yaml.v2 v2.4.0
+	tinygo.org/x/espflasher v0.6.0
 	tinygo.org/x/go-llvm v0.0.0-20250422114502-b8f170971e74
 )
 
 require (
+	github.com/BurntSushi/toml v1.4.0 // indirect
+	github.com/chavacava/garif v0.1.0 // indirect
+	github.com/coreos/go-semver v0.3.1 // indirect
 	github.com/creack/goselect v0.1.2 // indirect
+	github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 // indirect
+	github.com/fatih/color v1.17.0 // indirect
+	github.com/fatih/structtag v1.2.0 // indirect
+	github.com/hashicorp/go-version v1.7.0 // indirect
+	github.com/klauspost/compress v1.17.11 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
-	github.com/stretchr/testify v1.8.4 // indirect
+	github.com/mattn/go-runewidth v0.0.9 // indirect
+	github.com/mgechev/dots v0.0.0-20210922191527-e955255bf517 // indirect
+	github.com/mitchellh/go-homedir v1.1.0 // indirect
+	github.com/olekukonko/tablewriter v0.0.5 // indirect
+	github.com/opencontainers/go-digest v1.0.0 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/regclient/regclient v0.8.2 // indirect
+	github.com/sirupsen/logrus v1.9.3 // indirect
+	github.com/spf13/afero v1.11.0 // indirect
+	github.com/ulikunitz/xz v0.5.12 // indirect
+	github.com/urfave/cli/v3 v3.0.0-beta1 // indirect
+	golang.org/x/mod v0.23.0 // indirect
 	golang.org/x/text v0.22.0 // indirect
 )

go.sum

@@ -1,17 +1,36 @@
+github.com/BurntSushi/toml v1.4.0 h1:kuoIxZQy2WRRk1pttg9asf+WVv6tWQuBNVmK8+nqPr0=
+github.com/BurntSushi/toml v1.4.0/go.mod h1:ukJfTF/6rtPPRCnwkur4qwRxa8vTRFBF0uk2lLoLwho=
 github.com/aykevl/go-wasm v0.0.2-0.20250317121156-42b86c494139 h1:2O/WuAt8J5id3khcAtVB90czG80m+v0sfkLE07GrCVg=
 github.com/aykevl/go-wasm v0.0.2-0.20250317121156-42b86c494139/go.mod h1:7sXyiaA0WtSogCu67R2252fQpVmJMh9JWJ9ddtGkpWw=
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2 h1:oMCHnXa6CCCafdPDbMh/lWRhRByN0VFLvv+g+ayx1SI=
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2/go.mod h1:PkYb9DJNAwrSvRx5DYA+gUcOIgTGVMNkfSCbZM8cWpI=
+github.com/chavacava/garif v0.1.0 h1:2JHa3hbYf5D9dsgseMKAmc/MZ109otzgNFk5s87H9Pc=
+github.com/chavacava/garif v0.1.0/go.mod h1:XMyYCkEL58DF0oyW4qDjjnPWONs2HBqYKI+UIPD+Gww=
+github.com/coreos/go-semver v0.3.1 h1:yi21YpKnrx1gt5R+la8n5WgS0kCrsPp33dmEyHReZr4=
+github.com/coreos/go-semver v0.3.1/go.mod h1:irMmmIw/7yzSRPWryHsK7EYSg09caPQL03VsM8rvUec=
 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/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 h1:UhxFibDNY/bfvqU5CAUmr9zpesgbU6SWc8/B4mflAE4=
+github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7/go.mod h1:cyGadeNEkKy96OOhEzfZl+yxihPEzKnqJwvfuSUqbZE=
+github.com/fatih/color v1.17.0 h1:GlRw1BRJxkpqUCBKzKOw098ed57fEsKeNjpTe3cSjK4=
+github.com/fatih/color v1.17.0/go.mod h1:YZ7TlrGPkiz6ku9fK3TLD/pl3CpsiFyu8N92HLgmosI=
+github.com/fatih/structtag v1.2.0 h1:/OdNE99OxoI/PqaW/SuSK9uxxT3f/tcSZgon/ssNSx4=
+github.com/fatih/structtag v1.2.0/go.mod h1:mBJUNpUnHmRKrKlQQlmCrh5PuhftFbNv8Ys4/aAZl94=
 github.com/gofrs/flock v0.8.1 h1:+gYjHKf32LDeiEEFhQaotPbLuUXjY5ZqxKgXy7n59aw=
 github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
+github.com/golangci/misspell v0.6.0 h1:JCle2HUTNWirNlDIAUO44hUsKhOFqGPoC4LZxlaSXDs=
+github.com/golangci/misspell v0.6.0/go.mod h1:keMNyY6R9isGaSAu+4Q8NMBwMPkh15Gtc8UCVoDtAWo=
 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/hashicorp/go-version v1.7.0 h1:5tqGy27NaOTB8yJKUZELlFAS/LTKJkrmONwQKeRZfjY=
+github.com/hashicorp/go-version v1.7.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
 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/klauspost/compress v1.17.11 h1:In6xLpyWOi1+C7tXUUWv2ot1QvBjxevKAaI6IXrJmUc=
+github.com/klauspost/compress v1.17.11/go.mod h1:pMDklpSncoRMuLFrf1W9Ss9KT+0rH90U12bZKk7uwG0=
 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=
@@ -23,18 +42,57 @@ github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/
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+go.bug.st/serial v1.6.4 h1:7FmqNPgVp3pu2Jz5PoPtbZ9jJO5gnEnZIvnI1lzve8A=
+go.bug.st/serial v1.6.4/go.mod h1:nofMJxTeNVny/m6+KaafC6vJGj3miwQZ6vW4BZUGJPI=
+go.bytecodealliance.org v0.6.2 h1:Jy4u5DVmSkXgsnwojBhJ+AD/YsJsR3VzVnxF0xRCqTQ=
+go.bytecodealliance.org v0.6.2/go.mod h1:gqjTJm0y9NSksG4py/lSjIQ/SNuIlOQ+hCIEPQwtJgA=
+go.bytecodealliance.org/cm v0.2.2 h1:M9iHS6qs884mbQbIjtLX1OifgyPG9DuMs2iwz8G4WQA=
+go.bytecodealliance.org/cm v0.2.2/go.mod h1:JD5vtVNZv7sBoQQkvBvAAVKJPhR/bqBH7yYXTItMfZI=
 golang.org/x/mod v0.23.0 h1:Zb7khfcRGKk+kqfxFaP5tZqCnDZMjC5VtUBs87Hr6QM=
 golang.org/x/mod v0.23.0/go.mod h1:6SkKJ3Xj0I0BrPOZoBy3bdMptDDU9oJrpohJ3eWZ1fY=
 golang.org/x/net v0.35.0 h1:T5GQRQb2y08kTAByq9L4/bz8cipCdA8FbRTXewonqY8=
@@ -44,6 +102,7 @@ golang.org/x/sync v0.11.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 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 v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
@@ -56,7 +115,10 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 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/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 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/espflasher v0.6.0 h1:CHbGMHAIWq1tB8FKd/QwBpNFw1jvHHxpmvZiF+QOYUo=
+tinygo.org/x/espflasher v0.6.0/go.mod h1:tr5u08HoE67WD5zxJesCiiVF/R1b6Akz3yXwh5zah8U=
 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=

goenv/version.go

@@ -10,7 +10,7 @@ import (
 
 // Version of TinyGo.
 // Update this value before release of new version of software.
-const version = "0.41.0-dev"
+const version = "0.41.1"
 
 // Return TinyGo version, either in the form 0.30.0 or as a development version
 // (like 0.30.0-dev-abcd012).

internal/tools/go.mod

@@ -1,30 +0,0 @@
-// TODO: remove this (by merging it into the top-level go.mod)
-// once the top level go.mod specifies a go new enough to make our version of misspell happy.
-
-module tools
-
-go 1.21
-
-require (
-	github.com/golangci/misspell v0.6.0
-	github.com/mgechev/revive v1.3.9
-)
-
-require (
-	github.com/BurntSushi/toml v1.4.0 // indirect
-	github.com/chavacava/garif v0.1.0 // indirect
-	github.com/fatih/color v1.17.0 // indirect
-	github.com/fatih/structtag v1.2.0 // indirect
-	github.com/hashicorp/go-version v1.7.0 // indirect
-	github.com/mattn/go-colorable v0.1.13 // indirect
-	github.com/mattn/go-isatty v0.0.20 // indirect
-	github.com/mattn/go-runewidth v0.0.9 // indirect
-	github.com/mgechev/dots v0.0.0-20210922191527-e955255bf517 // indirect
-	github.com/mitchellh/go-homedir v1.1.0 // indirect
-	github.com/olekukonko/tablewriter v0.0.5 // indirect
-	github.com/pkg/errors v0.9.1 // indirect
-	github.com/spf13/afero v1.11.0 // indirect
-	golang.org/x/sys v0.22.0 // indirect
-	golang.org/x/text v0.14.0 // indirect
-	golang.org/x/tools v0.23.0 // indirect
-)

internal/tools/go.sum

@@ -1,56 +0,0 @@
-github.com/BurntSushi/toml v1.4.0 h1:kuoIxZQy2WRRk1pttg9asf+WVv6tWQuBNVmK8+nqPr0=
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-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
-github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
-github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
-golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/tools v0.23.0 h1:SGsXPZ+2l4JsgaCKkx+FQ9YZ5XEtA1GZYuoDjenLjvg=
-golang.org/x/tools v0.23.0/go.mod h1:pnu6ufv6vQkll6szChhK3C3L/ruaIv5eBeztNG8wtsI=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/wasm-tools/README.md

@@ -1,5 +0,0 @@
-# wasm-tools directory
-
-This directory has a separate `go.mod` file because the `wasm-tools-go` module requires Go 1.22, while TinyGo itself supports Go 1.19.
-
-When the minimum Go version for TinyGo is 1.22, this directory can be folded into `internal/tools` and the `go.mod` and `go.sum` files deleted.

internal/wasm-tools/go.mod

@@ -1,22 +0,0 @@
-module github.com/tinygo-org/tinygo/internal/wasm-tools
-
-go 1.23.0
-
-require (
-	go.bytecodealliance.org v0.6.2
-	go.bytecodealliance.org/cm v0.2.2
-)
-
-require (
-	github.com/coreos/go-semver v0.3.1 // indirect
-	github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 // indirect
-	github.com/klauspost/compress v1.18.0 // indirect
-	github.com/opencontainers/go-digest v1.0.0 // indirect
-	github.com/regclient/regclient v0.8.2 // indirect
-	github.com/sirupsen/logrus v1.9.3 // indirect
-	github.com/tetratelabs/wazero v1.9.0 // indirect
-	github.com/ulikunitz/xz v0.5.12 // indirect
-	github.com/urfave/cli/v3 v3.0.0-beta1 // indirect
-	golang.org/x/mod v0.24.0 // indirect
-	golang.org/x/sys v0.31.0 // indirect
-)

internal/wasm-tools/go.sum

@@ -1,48 +0,0 @@
-github.com/coreos/go-semver v0.3.1 h1:yi21YpKnrx1gt5R+la8n5WgS0kCrsPp33dmEyHReZr4=
-github.com/coreos/go-semver v0.3.1/go.mod h1:irMmmIw/7yzSRPWryHsK7EYSg09caPQL03VsM8rvUec=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 h1:UhxFibDNY/bfvqU5CAUmr9zpesgbU6SWc8/B4mflAE4=
-github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7/go.mod h1:cyGadeNEkKy96OOhEzfZl+yxihPEzKnqJwvfuSUqbZE=
-github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
-github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
-github.com/olareg/olareg v0.1.1 h1:Ui7q93zjcoF+U9U71sgqgZWByDoZOpqHitUXEu2xV+g=
-github.com/olareg/olareg v0.1.1/go.mod h1:w8NP4SWrHHtxsFaUiv1lnCnYPm4sN1seCd2h7FK/dc0=
-github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
-github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
-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/regclient/regclient v0.8.2 h1:23BQ3jWgKYHHIXUhp/S9laVJDHDoOQaQCzXMJ4undVE=
-github.com/regclient/regclient v0.8.2/go.mod h1:uGyetv0o6VLyRDjtfeBqp/QBwRLJ3Hcn07/+8QbhNcM=
-github.com/sergi/go-diff v1.3.1 h1:xkr+Oxo4BOQKmkn/B9eMK0g5Kg/983T9DqqPHwYqD+8=
-github.com/sergi/go-diff v1.3.1/go.mod h1:aMJSSKb2lpPvRNec0+w3fl7LP9IOFzdc9Pa4NFbPK1I=
-github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
-github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
-github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-github.com/tetratelabs/wazero v1.9.0 h1:IcZ56OuxrtaEz8UYNRHBrUa9bYeX9oVY93KspZZBf/I=
-github.com/tetratelabs/wazero v1.9.0/go.mod h1:TSbcXCfFP0L2FGkRPxHphadXPjo1T6W+CseNNY7EkjM=
-github.com/ulikunitz/xz v0.5.12 h1:37Nm15o69RwBkXM0J6A5OlE67RZTfzUxTj8fB3dfcsc=
-github.com/ulikunitz/xz v0.5.12/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=
-github.com/urfave/cli/v3 v3.0.0-beta1 h1:6DTaaUarcM0wX7qj5Hcvs+5Dm3dyUTBbEwIWAjcw9Zg=
-github.com/urfave/cli/v3 v3.0.0-beta1/go.mod h1:FnIeEMYu+ko8zP1F9Ypr3xkZMIDqW3DR92yUtY39q1Y=
-go.bytecodealliance.org v0.6.2 h1:Jy4u5DVmSkXgsnwojBhJ+AD/YsJsR3VzVnxF0xRCqTQ=
-go.bytecodealliance.org v0.6.2/go.mod h1:gqjTJm0y9NSksG4py/lSjIQ/SNuIlOQ+hCIEPQwtJgA=
-go.bytecodealliance.org/cm v0.2.2 h1:M9iHS6qs884mbQbIjtLX1OifgyPG9DuMs2iwz8G4WQA=
-go.bytecodealliance.org/cm v0.2.2/go.mod h1:JD5vtVNZv7sBoQQkvBvAAVKJPhR/bqBH7yYXTItMfZI=
-golang.org/x/mod v0.24.0 h1:ZfthKaKaT4NrhGVZHO1/WDTwGES4De8KtWO0SIbNJMU=
-golang.org/x/mod v0.24.0/go.mod h1:IXM97Txy2VM4PJ3gI61r1YEk/gAj6zAHN3AdZt6S9Ww=
-golang.org/x/sync v0.11.0 h1:GGz8+XQP4FvTTrjZPzNKTMFtSXH80RAzG+5ghFPgK9w=
-golang.org/x/sync v0.11.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.31.0 h1:ioabZlmFYtWhL+TRYpcnNlLwhyxaM9kWTDEmfnprqik=
-golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/tools v0.30.0 h1:BgcpHewrV5AUp2G9MebG4XPFI1E2W41zU1SaqVA9vJY=
-golang.org/x/tools v0.30.0/go.mod h1:c347cR/OJfw5TI+GfX7RUPNMdDRRbjvYTS0jPyvsVtY=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/wasm-tools/tools.go

@@ -1,12 +0,0 @@
-//go:build tools
-
-// Install tools specified in go.mod.
-// See https://marcofranssen.nl/manage-go-tools-via-go-modules for idiom.
-package tools
-
-import (
-	_ "go.bytecodealliance.org/cm"
-	_ "go.bytecodealliance.org/cmd/wit-bindgen-go"
-)
-
-//go:generate go install go.bytecodealliance.org/cmd/wit-bindgen-go

interp/errors.go

@@ -29,7 +29,7 @@ var errInvalidPtrToIntSize = errors.New("interp: ptrtoint integer size does not
 func isRecoverableError(err error) bool {
 	return err == errIntegerAsPointer || err == errUnsupportedInst ||
 		err == errUnsupportedRuntimeInst || err == errMapAlreadyCreated ||
-		err == errLoopUnrolled
+		err == errLoopUnrolled || err == errInvalidPtrToIntSize
 }
 
 // ErrorLine is one line in a traceback. The position may be missing.

interp/interpreter.go

@@ -413,64 +413,6 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				// Special function that will trigger an error.
 				// This is used to test error reporting.
 				return nil, mem, r.errorAt(inst, errors.New("test error"))
-			case strings.HasSuffix(callFn.name, ".$typeassert"):
-				if r.debug {
-					fmt.Fprintln(os.Stderr, indent+"interface assert:", operands[1:])
-				}
-
-				// Load various values for the interface implements check below.
-				typecodePtr, err := operands[1].asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				// typecodePtr always point to the numMethod field in the type
-				// description struct. The methodSet, when present, comes right
-				// before the numMethod field (the compiler doesn't generate
-				// method sets for concrete types without methods).
-				// Considering that the compiler doesn't emit interface type
-				// asserts for interfaces with no methods (as the always succeed)
-				// then if the offset is zero, this assert must always fail.
-				if typecodePtr.offset() == 0 {
-					locals[inst.localIndex] = literalValue{uint8(0)}
-					break
-				}
-				typecodePtrOffset, err := typecodePtr.addOffset(-int64(r.pointerSize))
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				methodSetPtr, err := mem.load(typecodePtrOffset, r.pointerSize).asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				methodSet := mem.get(methodSetPtr.index()).llvmGlobal.Initializer()
-				numMethods := int(r.builder.CreateExtractValue(methodSet, 0, "").ZExtValue())
-				llvmFn := inst.llvmInst.CalledValue()
-				methodSetAttr := llvmFn.GetStringAttributeAtIndex(-1, "tinygo-methods")
-				methodSetString := methodSetAttr.GetStringValue()
-
-				// Make a set of all the methods on the concrete type, for
-				// easier checking in the next step.
-				concreteTypeMethods := map[string]struct{}{}
-				for i := 0; i < numMethods; i++ {
-					methodInfo := r.builder.CreateExtractValue(methodSet, 1, "")
-					name := r.builder.CreateExtractValue(methodInfo, i, "").Name()
-					concreteTypeMethods[name] = struct{}{}
-				}
-
-				// Check whether all interface methods are also in the list
-				// of defined methods calculated above. This is the interface
-				// assert itself.
-				assertOk := uint8(1) // i1 true
-				for _, name := range strings.Split(methodSetString, "; ") {
-					if _, ok := concreteTypeMethods[name]; !ok {
-						// There is a method on the interface that is not
-						// implemented by the type. The assertion will fail.
-						assertOk = 0 // i1 false
-						break
-					}
-				}
-				// If assertOk is still 1, the assertion succeeded.
-				locals[inst.localIndex] = literalValue{assertOk}
 			case strings.HasSuffix(callFn.name, "$invoke"):
 				// This thunk is the interface method dispatcher: it is called
 				// with all regular parameters and a type code. It will then

loader/goroot.go

@@ -245,6 +245,7 @@ func pathsToOverride(goMinor int, needsSyscallPackage bool) map[string]bool {
 		"internal/cm/":                false,
 		"internal/futex/":             false,
 		"internal/fuzz/":              false,
+		"internal/itoa":               false,
 		"internal/reflectlite/":       false,
 		"internal/gclayout":           false,
 		"internal/task/":              false,
@@ -267,11 +268,31 @@ func pathsToOverride(goMinor int, needsSyscallPackage bool) map[string]bool {
 		paths["crypto/internal/boring/sig/"] = false
 	}
 
+	if goMinor >= 26 {
+		// Go 1.26 added a CPU jitter entropy source for FIPS 140-3 that
+		// allocates a 32 MiB global buffer (ScratchBuffer [1<<25]byte).
+		// This is fine on systems with virtual memory, but causes RAM
+		// overflow on microcontrollers. Replace with a zero-size stub
+		// since TinyGo targets never use FIPS jitter entropy.
+		paths["crypto/internal/entropy/"] = true
+		paths["crypto/internal/entropy/v1.0.0/"] = false
+	}
+
 	if needsSyscallPackage {
 		paths["syscall/"] = true // include syscall/js
 		paths["internal/syscall/"] = true
 		paths["internal/syscall/unix/"] = false
 	}
+
+	if goMinor >= 26 {
+		// Go 1.26 added SWAR optimizations to unicode/utf8 that use
+		// constants assuming at least 32-bit uintptr. TinyGo supports
+		// 16-bit targets (AVR) where these constants overflow, so we
+		// provide a patched version.
+		paths["unicode/"] = true
+		paths["unicode/utf8/"] = false
+	}
+
 	return paths
 }
 

loader/loader.go

@@ -549,7 +549,7 @@ func (p *Package) extractEmbedLines(addError func(error)) {
 					}
 
 					// Look for //go:embed comments.
-					var allPatterns []string
+					var allPatterns []embedPattern
 					for _, comment := range doc.List {
 						if comment.Text != "//go:embed" && !strings.HasPrefix(comment.Text, "//go:embed ") {
 							continue
@@ -577,21 +577,7 @@ func (p *Package) extractEmbedLines(addError func(error)) {
 							})
 							continue
 						}
-						for _, pattern := range patterns {
-							// Check that the pattern is well-formed.
-							// It must be valid: the Go toolchain has already
-							// checked for invalid patterns. But let's check
-							// anyway to be sure.
-							if _, err := path.Match(pattern, ""); err != nil {
-								addError(types.Error{
-									Fset: p.program.fset,
-									Pos:  comment.Pos(),
-									Msg:  "invalid pattern syntax",
-								})
-								continue
-							}
-							allPatterns = append(allPatterns, pattern)
-						}
+						allPatterns = append(allPatterns, patterns...)
 					}
 
 					if len(allPatterns) != 0 {
@@ -624,8 +610,8 @@ func (p *Package) extractEmbedLines(addError func(error)) {
 						// Match all //go:embed patterns against the embed files
 						// provided by `go list`.
 						for _, name := range p.EmbedFiles {
-							for _, pattern := range allPatterns {
-								if matchPattern(pattern, name) {
+							for _, ep := range allPatterns {
+								if ep.Match(name) {
 									p.EmbedGlobals[globalName] = append(p.EmbedGlobals[globalName], &EmbedFile{
 										Name:      name,
 										NeedsData: byteSlice,
@@ -641,13 +627,37 @@ func (p *Package) extractEmbedLines(addError func(error)) {
 	}
 }
 
-// matchPattern returns true if (and only if) the given pattern would match the
-// filename. The pattern could also match a parent directory of name, in which
-// case hidden files do not match.
-func matchPattern(pattern, name string) bool {
+// embedPattern represents a valid //go:embed pattern.
+// See: https://pkg.go.dev/embed#hdr-Directives
+type embedPattern struct {
+	pattern       string // glob pattern without "all:" prefix
+	includeHidden bool   // true if "all:" prefix was present
+}
+
+// newEmbedPattern parses and validates a //go:embed pattern.
+// The "all:" prefix (if present) is stripped and reflected in includeHidden.
+// Returns an error if the pattern syntax is invalid.
+func newEmbedPattern(s string) (embedPattern, error) {
+	ep := embedPattern{pattern: s}
+	if strings.HasPrefix(s, "all:") {
+		ep.pattern = s[4:]
+		ep.includeHidden = true
+	}
+	if _, err := path.Match(ep.pattern, ""); err != nil {
+		return embedPattern{}, err
+	}
+	return ep, nil
+}
+
+// Match returns true if (and only if) the pattern matches the given filename.
+// The pattern could also match a parent directory of name, in which case hidden
+// files do not match (unless includeHidden is true).
+func (ep embedPattern) Match(name string) bool {
+	pattern := ep.pattern
+	includeHidden := ep.includeHidden
+
 	// Match this file.
-	matched, _ := path.Match(pattern, name)
-	if matched {
+	if matched, _ := path.Match(pattern, name); matched {
 		return true
 	}
 
@@ -661,17 +671,20 @@ func matchPattern(pattern, name string) bool {
 		dir = path.Clean(dir)
 		if matched, _ := path.Match(pattern, dir); matched {
 			// Pattern matches the directory.
-			suffix := name[len(dir):]
-			if strings.Contains(suffix, "/_") || strings.Contains(suffix, "/.") {
-				// Pattern matches a hidden file.
-				// Hidden files are included when listed directly as a
-				// pattern, but not when they are part of a directory tree.
-				// Source:
-				// > If a pattern names a directory, all files in the
-				// > subtree rooted at that directory are embedded
-				// > (recursively), except that files with names beginning
-				// > with ‘.’ or ‘_’ are excluded.
-				return false
+			if !includeHidden {
+				suffix := name[len(dir):]
+				if strings.Contains(suffix, "/_") || strings.Contains(suffix, "/.") {
+					// Pattern matches a hidden file.
+					// Hidden files are included when listed directly as a
+					// pattern, or when the "all:" prefix is used, but not
+					// when they are part of a directory tree without "all:".
+					// Source:
+					// > If a pattern names a directory, all files in the
+					// > subtree rooted at that directory are embedded
+					// > (recursively), except that files with names beginning
+					// > with ‘.’ or ‘_’ are excluded.
+					return false
+				}
 			}
 			return true
 		}
@@ -680,11 +693,12 @@ func matchPattern(pattern, name string) bool {
 
 // parseGoEmbed is like strings.Fields but for a //go:embed line. It parses
 // regular fields and quoted fields (that may contain spaces).
-func (p *Package) parseGoEmbed(args string, pos token.Pos) (patterns []string, err error) {
+func (p *Package) parseGoEmbed(args string, pos token.Pos) (patterns []embedPattern, err error) {
 	args = strings.TrimSpace(args)
 	initialLen := len(args)
 	for args != "" {
 		patternPos := pos + token.Pos(initialLen-len(args))
+		var pattern string
 		switch args[0] {
 		case '`', '"', '\\':
 			// Parse the next pattern using the Go scanner.
@@ -703,8 +717,7 @@ func (p *Package) parseGoEmbed(args string, pos token.Pos) (patterns []string, e
 					Msg:  "invalid quoted string in //go:embed",
 				}
 			}
-			pattern := constant.StringVal(constant.MakeFromLiteral(lit, tok, 0))
-			patterns = append(patterns, pattern)
+			pattern = constant.StringVal(constant.MakeFromLiteral(lit, tok, 0))
 			args = strings.TrimLeftFunc(args[len(lit):], unicode.IsSpace)
 		default:
 			// The value is just a regular value.
@@ -713,17 +726,18 @@ func (p *Package) parseGoEmbed(args string, pos token.Pos) (patterns []string, e
 			if index < 0 {
 				index = len(args)
 			}
-			pattern := args[:index]
-			patterns = append(patterns, pattern)
+			pattern = args[:index]
 			args = strings.TrimLeftFunc(args[len(pattern):], unicode.IsSpace)
 		}
-		if _, err := path.Match(patterns[len(patterns)-1], ""); err != nil {
+		ep, err := newEmbedPattern(pattern)
+		if err != nil {
 			return nil, types.Error{
 				Fset: p.program.fset,
 				Pos:  patternPos,
 				Msg:  "invalid pattern syntax",
 			}
 		}
+		patterns = append(patterns, ep)
 	}
 	return patterns, nil
 }

main.go

@@ -32,12 +32,15 @@ import (
 	"github.com/tinygo-org/tinygo/goenv"
 	"github.com/tinygo-org/tinygo/loader"
 	"golang.org/x/tools/go/buildutil"
+	"tinygo.org/x/espflasher/pkg/espflasher"
 	"tinygo.org/x/go-llvm"
 
 	"go.bug.st/serial"
 	"go.bug.st/serial/enumerator"
 )
 
+var errInheritableOnly = errors.New("target is inheritable-only, which means it cannot be used directly for building or flashing")
+
 // commandError is an error type to wrap os/exec.Command errors. This provides
 // some more information regarding what went wrong while running a command.
 type commandError struct {
@@ -139,6 +142,10 @@ func printCommand(cmd string, args ...string) {
 
 // Build compiles and links the given package and writes it to outpath.
 func Build(pkgName, outpath string, config *compileopts.Config) error {
+	if config.Target != nil && config.Target.InheritableOnly {
+		return errInheritableOnly
+	}
+
 	// Create a temporary directory for intermediary files.
 	tmpdir, err := os.MkdirTemp("", "tinygo")
 	if err != nil {
@@ -356,6 +363,10 @@ func Flash(pkgName, port, outpath string, options *compileopts.Options) error {
 		return err
 	}
 
+	if config.Target != nil && config.Target.InheritableOnly {
+		return errInheritableOnly
+	}
+
 	// determine the type of file to compile
 	var fileExt string
 
@@ -385,6 +396,10 @@ func Flash(pkgName, port, outpath string, options *compileopts.Options) error {
 		fileExt = ".hex"
 	case "bmp":
 		fileExt = ".elf"
+	case "adb":
+		fileExt = ".hex"
+	case "esp32flash", "esp32jtag":
+		fileExt = ".bin"
 	case "native":
 		return errors.New("unknown flash method \"native\" - did you miss a -target flag?")
 	default:
@@ -519,6 +534,56 @@ func Flash(pkgName, port, outpath string, options *compileopts.Options) error {
 		if err != nil {
 			return &commandError{"failed to flash", result.Binary, err}
 		}
+	case "adb":
+		// Run pre-flash adb shell commands.
+		for _, preCmd := range config.Target.ADBPreCommands {
+			cmd := executeCommand(config.Options, "adb", "shell", preCmd)
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+			if err := cmd.Run(); err != nil {
+				return &commandError{"failed to run adb pre-command", preCmd, err}
+			}
+		}
+
+		// Push the binary to the device.
+		if config.Target.ADBPushRemote == "" {
+			return errors.New("invalid target file: flash-method was set to \"adb\" but no adb-push-remote was set")
+		}
+		cmd := executeCommand(config.Options, "adb", "push", result.Binary, config.Target.ADBPushRemote)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		if err := cmd.Run(); err != nil {
+			return &commandError{"adb push failed to " + config.Target.ADBPushRemote, result.Binary, err}
+		}
+
+		// Run post-flash adb shell commands.
+		for _, postCmd := range config.Target.ADBPostCommands {
+			postCmd = strings.ReplaceAll(postCmd, "{remote}", config.Target.ADBPushRemote)
+			cmd := executeCommand(config.Options, "adb", "shell", postCmd)
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+			if err := cmd.Run(); err != nil {
+				return &commandError{"failed to run adb post-command", postCmd, err}
+			}
+		}
+	case "esp32flash":
+		port, err := getDefaultPort(port, config.Target.SerialPort)
+		if err != nil {
+			return &commandError{"failed to find port", port, err}
+		}
+
+		if err := flashBinUsingEsp32(port, classicReset, result.Binary, config.Options); err != nil {
+			return &commandError{"failed to flash", result.Binary, err}
+		}
+	case "esp32jtag":
+		port, err := getDefaultPort(port, config.Target.SerialPort)
+		if err != nil {
+			return &commandError{"failed to find port", port, err}
+		}
+
+		if err := flashBinUsingEsp32(port, jtagReset, result.Binary, config.Options); err != nil {
+			return &commandError{"failed to flash", result.Binary, err}
+		}
 	default:
 		return fmt.Errorf("unknown flash method: %s", flashMethod)
 	}
@@ -765,6 +830,10 @@ func Run(pkgName string, options *compileopts.Options, cmdArgs []string) error {
 		return err
 	}
 
+	if config.Target != nil && config.Target.InheritableOnly {
+		return errInheritableOnly
+	}
+
 	_, err = buildAndRun(pkgName, config, os.Stdout, cmdArgs, nil, 0, func(cmd *exec.Cmd, result builder.BuildResult) error {
 		return cmd.Run()
 	})
@@ -1019,6 +1088,68 @@ func flashHexUsingMSD(volumes []string, tmppath string, options *compileopts.Opt
 	return errors.New("unable to locate any volume: [" + strings.Join(volumes, ",") + "]")
 }
 
+const (
+	defaultReset = "default"
+	classicReset = "classic"
+	jtagReset    = "jtag"
+)
+
+func flashBinUsingEsp32(port, resetMode, tmppath string, options *compileopts.Options) error {
+	opts := espflasher.DefaultOptions()
+	opts.Compress = true
+	opts.Logger = &espflasher.StdoutLogger{W: os.Stdout}
+	if options.BaudRate != 0 {
+		opts.FlashBaudRate = options.BaudRate
+	}
+
+	if resetMode == jtagReset {
+		opts.ResetMode = espflasher.ResetUSBJTAG
+	}
+
+	flasher, err := espflasher.New(port, opts)
+	if err != nil {
+		return err
+	}
+	defer flasher.Close()
+
+	chipName := flasher.ChipName()
+	offset := uint32(0x0)
+	if chipName == "ESP32" {
+		offset = 0x1000
+	}
+
+	// Read the firmware binary
+	data, err := os.ReadFile(tmppath)
+	if err != nil {
+		return err
+	}
+
+	if err := flasher.EraseFlash(); err != nil {
+		return fmt.Errorf("erase failed: %v", err)
+	}
+
+	progress := func(current, total int) {
+		pct := float64(current) / float64(total) * 100
+		bar := int(pct / 2)
+		fmt.Printf("\r[%-50s] %6.1f%%", strings.Repeat("#", bar)+strings.Repeat(".", 50-bar), pct)
+		if current >= total {
+			fmt.Println()
+		}
+	}
+
+	// Flash with progress reporting
+	err = flasher.FlashImage(data, offset, progress)
+	if err != nil {
+		return err
+	}
+	fmt.Println()
+
+	// Reset the device to run the new firmware
+	flasher.Reset()
+
+	return nil
+}
+
 type mountPoint struct {
 	name string
 	path string

main_test.go

@@ -107,6 +107,9 @@ func TestBuild(t *testing.T) {
 	if minor >= 23 {
 		tests = append(tests, "go1.23/")
 	}
+	if minor >= 24 {
+		tests = append(tests, "typealias.go")
+	}
 
 	if *testTarget != "" {
 		// This makes it possible to run one specific test (instead of all),
@@ -451,7 +454,7 @@ func runTestWithConfig(name string, t *testing.T, options compileopts.Options, c
 
 	// Build the test binary.
 	stdout := &bytes.Buffer{}
-	_, err = buildAndRun(pkgName, config, stdout, cmdArgs, environmentVars, time.Minute, func(cmd *exec.Cmd, result builder.BuildResult) error {
+	_, err = buildAndRun(pkgName, config, stdout, cmdArgs, environmentVars, 2*time.Minute, func(cmd *exec.Cmd, result builder.BuildResult) error {
 		return cmd.Run()
 	})
 	if err != nil {

src/crypto/internal/entropy/v1.0.0/entropy.go

@@ -0,0 +1,56 @@
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Stripped-down version of the entropy package for TinyGo.
+//
+// The upstream Go 1.26 package allocates a [1<<25]byte (32 MiB) global buffer
+// for CPU jitter-based SP 800-90B entropy collection. This is fine on systems
+// with virtual memory where BSS pages are lazily backed, but it causes a fatal
+// "RAM overflowed" error on microcontrollers and other memory-constrained
+// targets.
+//
+// Because FIPS 140-3 jitter entropy is never used on TinyGo targets (the DRBG
+// falls through to sysrand.Read when fips140.Enabled is false), this overlay
+// replaces the 32 MiB buffer with a zero-size type.
+package entropy
+
+// Version returns the version of the entropy source.
+func Version() string {
+	return "v1.0.0"
+}
+
+// ScratchBuffer is a large buffer in upstream Go (32 MiB). TinyGo replaces it
+// with a zero-size type since the CPU jitter entropy source is not used.
+type ScratchBuffer [0]byte
+
+// Seed returns a 384-bit seed with full entropy.
+// On TinyGo targets this is never called because FIPS mode is not enabled.
+func Seed(memory *ScratchBuffer) ([48]byte, error) {
+	panic("entropy: CPU jitter entropy source is not supported on TinyGo targets")
+}
+
+// Samples collects entropy samples. Not supported on TinyGo targets.
+func Samples(samples []uint8, memory *ScratchBuffer) error {
+	panic("entropy: CPU jitter entropy source is not supported on TinyGo targets")
+}
+
+// SHA384 computes SHA-384 over 1024 bytes. Not supported on TinyGo targets.
+func SHA384(p *[1024]byte) [48]byte {
+	panic("entropy: CPU jitter entropy source is not supported on TinyGo targets")
+}
+
+// TestingOnlySHA384 computes SHA-384 over arbitrary bytes. Not supported on TinyGo targets.
+func TestingOnlySHA384(p []byte) [48]byte {
+	panic("entropy: CPU jitter entropy source is not supported on TinyGo targets")
+}
+
+// RepetitionCountTest implements the repetition count test from SP 800-90B.
+func RepetitionCountTest(samples []uint8) error {
+	panic("entropy: CPU jitter entropy source is not supported on TinyGo targets")
+}
+
+// AdaptiveProportionTest implements the adaptive proportion test from SP 800-90B.
+func AdaptiveProportionTest(samples []uint8) error {
+	panic("entropy: CPU jitter entropy source is not supported on TinyGo targets")
+}

src/crypto/rand/rand_baremetal.go

@@ -1,4 +1,4 @@
-//go:build nrf || (stm32 && !(stm32f103 || stm32l0x1)) || (sam && atsamd51) || (sam && atsame5x) || esp32c3 || tkey || (tinygo.riscv32 && virt)
+//go:build nrf || (stm32 && !(stm32f103 || stm32l0x1)) || (sam && atsamd51) || (sam && atsame5x) || esp32c3 || esp32s3 || tkey || (tinygo.riscv32 && virt)
 
 // If you update the above build constraint, you'll probably also need to update
 // src/runtime/rand_hwrng.go.

src/device/esp/esp32s3.S

@@ -0,0 +1,397 @@
+// Startup code for the ESP32-S3 (Xtensa LX7, windowed ABI).
+//
+// The ROM bootloader loads IRAM/DRAM segments into SRAM but does NOT
+// configure flash cache/MMU.  We must:
+//   1. Set up the windowed-ABI register file and stack pointer.
+//   2. Set VECBASE and clear PS.EXCM (needed for callx4 window overflows).
+//   3. Disable watchdog timers.
+//   4. Configure the flash cache and MMU so IROM/DROM are accessible.
+//   5. Jump to runtime.main (in IROM).
+//
+// Cache/MMU init sequence (from NuttX esp_loader.c / ESP-IDF bootloader / esp-hal):
+//   Phase A — configure cache modes:
+//     a. rom_config_instruction_cache_mode(16KB, 8-way, 32B)
+//     b. rom_Cache_Suspend_DCache()
+//     c. rom_config_data_cache_mode(32KB, 8-way, 32B)
+//     d. Cache_Resume_DCache(0)
+//   Phase B — map flash pages:
+//     e. Disable caches
+//     f. Cache_MMU_Init() — reset all MMU entries to invalid
+//     g. Cache_Set_IDROM_MMU_Size() — set IROM/DROM entry split
+//     h. Write MMU entries mapping flash page 0 for IROM and DROM
+//     i. Clear bus-shut bits
+//     j. Enable caches + isync
+
+#define PS_WOE   0x00040000
+
+// -----------------------------------------------------------------------
+// Boot entry point — placed in IRAM by the linker.
+// -----------------------------------------------------------------------
+.section .text.call_start_cpu0
+    .literal_position
+    .align 4
+.Lstack_top_addr:
+    .long _stack_top
+.Lmain_addr:
+    .long main
+.Lvector_table_addr:
+    .long _vector_table
+// WDT register addresses
+.Lwdt_key:
+    .long 0x50D83AA1
+.Lrtc_wdt_protect:
+    .long 0x600080B0
+.Lrtc_wdt_config0:
+    .long 0x60008098
+.Ltimg0_wdt_protect:
+    .long 0x6001F064
+.Ltimg0_wdt_config0:
+    .long 0x6001F048
+.Ltimg1_wdt_protect:
+    .long 0x60020064
+.Ltimg1_wdt_config0:
+    .long 0x60020048
+.Lswd_protect:
+    .long 0x600080B8
+.Lswd_key:
+    .long 0x8F1D312A
+.Lswd_conf:
+    .long 0x600080B4
+.Lswd_disable:
+    .long 0x40000000
+// ROM function addresses (from ESP-IDF esp32s3.rom.ld)
+.Lrom_config_icache:
+    .long 0x40001a1c
+.Lrom_config_dcache:
+    .long 0x40001a28
+.Lrom_suspend_dcache:
+    .long 0x400018b4
+.LCache_Resume_DCache:
+    .long 0x400018c0
+.LCache_Disable_ICache:
+    .long 0x4000186c
+.LCache_Disable_DCache:
+    .long 0x40001884
+.LCache_MMU_Init:
+    .long 0x40001998
+.LCache_Set_IDROM_MMU_Size:
+    .long 0x40001914
+.LCache_Enable_ICache:
+    .long 0x40001878
+.LCache_Enable_DCache:
+    .long 0x40001890
+// Cache/MMU register addresses
+.Lmmu_table_base:
+    .long 0x600C5000
+.Licache_ctrl1_reg:
+    .long 0x600C4064
+.Ldcache_ctrl1_reg:
+    .long 0x600C4004
+// End-of-section symbols for multi-page MMU mapping.
+.Lirom_end:
+    .long _irom_end
+.Ldrom_end:
+    .long _drom_end
+.Lirom_base:
+    .long 0x42000000
+.Ldrom_base:
+    .long 0x3C000000
+
+.global call_start_cpu0
+call_start_cpu0:
+
+    // ---- 1. Windowed-ABI register file setup ----
+
+    // Disable WOE so we can safely manipulate WINDOWSTART.
+    rsr.ps a2
+    movi a3, ~(PS_WOE)
+    and a2, a2, a3
+    wsr.ps a2
+    rsync
+
+    // Set WINDOWSTART to 1 << WINDOWBASE (mark only current window as valid).
+    rsr.windowbase  a2
+    ssl  a2
+    movi a2, 1
+    sll  a2, a2
+    wsr.windowstart a2
+    rsync
+
+    // Load stack pointer.
+    l32r a1, .Lstack_top_addr
+
+    // Re-enable WOE.
+    rsr.ps a2
+    movi a3, PS_WOE
+    or a2, a2, a3
+    wsr.ps a2
+    rsync
+
+    // Enable FPU (coprocessor 0).
+    movi a2, 1
+    wsr.cpenable a2
+    rsync
+
+    // ---- 2. Disable all watchdog timers (IMMEDIATELY, before any delay) ----
+    l32r a3, .Lwdt_key
+    movi a4, 0
+
+    // RTC WDT
+    l32r a2, .Lrtc_wdt_protect
+    memw
+    s32i a3, a2, 0
+    l32r a5, .Lrtc_wdt_config0
+    memw
+    s32i a4, a5, 0
+    memw
+    s32i a4, a2, 0
+
+    // TIMG0 WDT
+    l32r a2, .Ltimg0_wdt_protect
+    memw
+    s32i a3, a2, 0
+    l32r a5, .Ltimg0_wdt_config0
+    memw
+    s32i a4, a5, 0
+    memw
+    s32i a4, a2, 0
+
+    // TIMG1 WDT
+    l32r a2, .Ltimg1_wdt_protect
+    memw
+    s32i a3, a2, 0
+    l32r a5, .Ltimg1_wdt_config0
+    memw
+    s32i a4, a5, 0
+    memw
+    s32i a4, a2, 0
+
+    // Super WDT
+    l32r a2, .Lswd_protect
+    l32r a3, .Lswd_key
+    memw
+    s32i a3, a2, 0
+    l32r a5, .Lswd_conf
+    l32r a6, .Lswd_disable
+    memw
+    s32i a6, a5, 0
+    memw
+    s32i a4, a2, 0
+
+    // ---- 3. Set VECBASE and clear PS.EXCM ----
+    // VECBASE must be set before any callx4 so that window overflow
+    // exceptions (triggered by register window rotation) route to our
+    // handlers in IRAM, not the ROM's default vectors.
+    l32r a8, .Lvector_table_addr
+    wsr.vecbase a8
+    rsync
+
+    // Clear PS.EXCM (bit 4) and PS.INTLEVEL (bits 0-3).
+    // The ROM bootloader may leave EXCM=1; with EXCM set any callx4
+    // window overflow would become a double exception.
+    // Set PS.UM (bit 5) so level-1 exceptions route to User vector.
+    rsr.ps a2
+    movi a3, ~0x1F
+    and a2, a2, a3
+    movi a3, 0x20
+    or a2, a2, a3
+    wsr.ps a2
+    rsync
+
+    // ---- 4. Configure flash cache and MMU ----
+    //
+    // ROM function calls use callx4 (windowed ABI):
+    //   a4 = target address (overwritten with return addr by call mechanism)
+    //   a5 = stack pointer for callee (becomes callee's a1 via entry)
+    //   a6 = first argument  (becomes callee's a2)
+    //   a7 = second argument (becomes callee's a3)
+    //   a8 = third argument  (becomes callee's a4)
+    // Registers a0-a3 are preserved across callx4; a4-a11 may be clobbered.
+
+    // Phase A: Configure cache modes (required for cache hardware to function).
+    // Without this, the cache doesn't know its size/associativity/line-size
+    // and cannot service flash accesses.
+
+    // 4a. Configure ICache mode: 16KB, 8-way, 32-byte line
+    movi a6, 0x4000         // cache_size = 16KB
+    movi a7, 8              // ways = 8
+    movi a8, 32             // line_size = 32
+    mov  a5, a1
+    l32r a4, .Lrom_config_icache
+    callx4 a4
+
+    // 4b. Suspend DCache before configuring it
+    mov  a5, a1
+    l32r a4, .Lrom_suspend_dcache
+    callx4 a4
+
+    // 4c. Configure DCache mode: 32KB, 8-way, 32-byte line
+    movi a6, 0x8000         // cache_size = 32KB
+    movi a7, 8              // ways = 8
+    movi a8, 32             // line_size = 32
+    mov  a5, a1
+    l32r a4, .Lrom_config_dcache
+    callx4 a4
+
+    // 4d. Resume DCache
+    movi a6, 0
+    mov  a5, a1
+    l32r a4, .LCache_Resume_DCache
+    callx4 a4
+
+    // Phase B: Map flash pages into MMU.
+
+    // 4e. Disable ICache
+    mov  a5, a1
+    l32r a4, .LCache_Disable_ICache
+    callx4 a4
+
+    // 4f. Disable DCache
+    mov  a5, a1
+    l32r a4, .LCache_Disable_DCache
+    callx4 a4
+
+    // 4g. Initialize MMU (resets all 512 entries to invalid = 0x4000)
+    mov  a5, a1
+    l32r a4, .LCache_MMU_Init
+    callx4 a4
+
+    // 4h. Set IDROM MMU size: even 256/256 split.
+    //     Each entry is 4 bytes, so 256 entries = 0x400 bytes per region.
+    movi a6, 0x400          // irom_mmu_size  (256 entries × 4 bytes)
+    movi a7, 0x400          // drom_mmu_size  (256 entries × 4 bytes)
+    mov  a5, a1
+    l32r a4, .LCache_Set_IDROM_MMU_Size
+    callx4 a4
+
+    // 4i. Map flash pages for IROM and DROM using identity mapping.
+    //     MMU table at 0x600C5000: entries 0-255 = ICache, 256-511 = DCache.
+    //     Entry value N = flash page N (SOC_MMU_VALID = 0 on S3).
+    //     Each 64KB page needs one 4-byte entry.
+    //
+    //     IROM: map pages 0..N where N = (_irom_end - 0x42000000) >> 16
+    //     DROM: map pages 0..M where M = (_drom_end - 0x3C000000) >> 16
+
+    l32r a8, .Lmmu_table_base          // a8 = 0x600C5000
+
+    // --- IROM pages ---
+    l32r a2, .Lirom_end                // a2 = _irom_end (VMA in 0x42xxxxxx)
+    l32r a3, .Lirom_base               // a3 = 0x42000000
+    sub  a2, a2, a3                    // a2 = byte offset past IROM base
+    srli a2, a2, 16                    // a2 = last page index
+    addi a2, a2, 1                     // a2 = number of pages to map
+    movi a9, 0                         // a9 = page counter (and entry value)
+    mov  a10, a8                       // a10 = current MMU entry pointer
+.Lirom_loop:
+    s32i a9, a10, 0
+    addi a9, a9, 1
+    addi a10, a10, 4
+    blt  a9, a2, .Lirom_loop
+
+    // --- DROM pages ---
+    l32r a2, .Ldrom_end                // a2 = _drom_end (VMA in 0x3Cxxxxxx)
+    l32r a3, .Ldrom_base               // a3 = 0x3C000000
+    sub  a2, a2, a3                    // a2 = byte offset past DROM base
+    srli a2, a2, 16                    // a2 = last page index
+    addi a2, a2, 1                     // a2 = number of pages to map
+    movi a9, 0                         // a9 = page counter (and entry value)
+    addmi a10, a8, 0x400              // a10 = 0x600C5400 (DCache entry 256)
+.Ldrom_loop:
+    s32i a9, a10, 0
+    addi a9, a9, 1
+    addi a10, a10, 4
+    blt  a9, a2, .Ldrom_loop
+    memw
+
+    // 4j. Clear bus-shut bits so core 0 can access ICache and DCache buses.
+    l32r a8, .Licache_ctrl1_reg         // 0x600C4064
+    movi a9, 0
+    s32i a9, a8, 0                      // Clear all ICACHE_CTRL1 shut bits
+    l32r a8, .Ldcache_ctrl1_reg         // 0x600C4004
+    s32i a9, a8, 0                      // Clear all DCACHE_CTRL1 shut bits
+    memw
+
+    // 4k. Enable ICache (arg: autoload = 0)
+    movi a6, 0
+    mov  a5, a1
+    l32r a4, .LCache_Enable_ICache
+    callx4 a4
+
+    // 4l. Enable DCache (arg: autoload = 0)
+    movi a6, 0
+    mov  a5, a1
+    l32r a4, .LCache_Enable_DCache
+    callx4 a4
+
+    // Flush instruction pipeline so new cache/MMU config takes effect.
+    isync
+
+    // ---- 5. Jump to main (in IROM) ----
+    // Re-clear PS.EXCM in case ROM calls changed processor state.
+    rsr.ps a2
+    movi a3, ~0x1F
+    and a2, a2, a3
+    movi a3, 0x20
+    or a2, a2, a3
+    wsr.ps a2
+    rsync
+
+    mov  a5, a1
+    l32r a4, .Lmain_addr
+    callx4 a4
+
+    // If main returns, loop forever.
+1:  j 1b
+
+// -----------------------------------------------------------------------
+// tinygo_scanCurrentStack — Spill all Xtensa register windows to the
+// stack, then call tinygo_scanstack(sp) so the conservative GC can
+// discover live heap pointers that are currently in physical registers.
+//
+// On RISC-V / ARM the equivalent function pushes callee-saved registers
+// before the call.  On Xtensa windowed ABI the same effect is achieved
+// by forcing hardware window-overflow for every occupied pane: each
+// overflow saves the four registers in that pane to the stack frame
+// pointed to by the pane's a1 (sp).  After all panes are flushed, a
+// scan from the current sp to stackTop covers every live value.
+// -----------------------------------------------------------------------
+.section .text.tinygo_scanCurrentStack
+
+.global tinygo_scanCurrentStack
+tinygo_scanCurrentStack:
+    entry a1, 48
+
+    // Disable interrupts while flushing register windows.
+    rsr   a4, PS
+    s32i  a4, a1, 0         // save PS for later restore
+    rsil  a4, 3             // XCHAL_EXCM_LEVEL
+
+    // Flush all register windows using recursive call4.
+    // For NAREG=64 (16 panes), 15 recursive levels cover all panes
+    // except the current one (which is kept active).
+    movi a6, 15
+    call4 .Lscan_spill
+
+    // Restore interrupts.
+    l32i  a4, a1, 0
+    wsr.ps a4
+    rsync
+
+    // Pass current sp to tinygo_scanstack.
+    // call4 maps caller's a5→callee's a1 (stack ptr for callee's entry)
+    // and caller's a6→callee's a2 (first argument = sp).
+    mov  a5, a1             // callee's a1 = valid stack pointer
+    mov  a6, a1             // callee's a2 = sp argument
+    call4 tinygo_scanstack
+
+    retw
+
+    .balign 4
+.Lscan_spill:
+    entry a1, 16
+    beqz  a2, .Lscan_spill_done
+    addi  a2, a2, -1
+    mov   a6, a2
+    call4 .Lscan_spill
+.Lscan_spill_done:
+    retw

src/device/riscv/handleinterrupt.S

@@ -75,6 +75,10 @@ handleInterruptASM:
     SFREG   f30,(30 + 16)*REGSIZE(sp)
     SFREG   f31,(31 + 16)*REGSIZE(sp)
 #endif
+    // Save ra to a global so handleException can print the caller of the NULL
+    // function pointer.
+    la      t0, tinygo_saved_ra
+    SREG    ra, 0(t0)
     call    handleInterrupt
 #ifdef __riscv_flen
     LFREG   f0, (31 + 16)*REGSIZE(sp)
@@ -128,3 +132,10 @@ handleInterruptASM:
     LREG    ra, 0*REGSIZE(sp)
     addi    sp, sp, NREG*REGSIZE
     mret
+
+.section .bss.tinygo_saved_ra
+.global tinygo_saved_ra
+.type tinygo_saved_ra,@object
+.align 2
+tinygo_saved_ra:
+    .space REGSIZE

src/examples/adc/adc.go

@@ -5,25 +5,15 @@ import (
 	"time"
 )
 
-// This example assumes that an analog sensor such as a rotary dial is connected to pin ADC0.
-// When the dial is turned past the midway point, the built-in LED will light up.
-
 func main() {
 	machine.InitADC()
 
-	led := machine.LED
-	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
-
 	sensor := machine.ADC{machine.ADC2}
 	sensor.Configure(machine.ADCConfig{})
 
 	for {
 		val := sensor.Get()
-		if val < 0x8000 {
-			led.Low()
-		} else {
-			led.High()
-		}
-		time.Sleep(time.Millisecond * 100)
+		println(val)
+		time.Sleep(time.Millisecond * 500)
 	}
 }

src/examples/pininterrupt/arduino-uno.go

@@ -1,4 +1,4 @@
-//go:build arduino
+//go:build arduino_uno
 
 package main
 

src/examples/pininterrupt/xiao-esp32s3.go

@@ -0,0 +1,11 @@
+//go:build xiao_esp32s3
+
+package main
+
+import "machine"
+
+const (
+	button          = machine.D1
+	buttonMode      = machine.PinInputPullup
+	buttonPinChange = machine.PinFalling
+)

src/examples/pwm/arduino-uno-q.go

@@ -0,0 +1,11 @@
+//go:build arduino_uno_q
+
+package main
+
+import "machine"
+
+var (
+	pwm  = &machine.TIM3
+	pinA = machine.D3 // PB0 = TIM3_CH3
+	pinB = machine.D6 // PB1 = TIM3_CH4
+)

src/examples/pwm/arduino-uno.go

@@ -1,4 +1,4 @@
-//go:build arduino
+//go:build arduino_uno
 
 package main
 

src/examples/pwm/esp32c3-supermini.go

@@ -0,0 +1,11 @@
+//go:build esp32c3_supermini
+
+package main
+
+import "machine"
+
+var (
+	pwm  = machine.PWM0
+	pinA = machine.GPIO5
+	pinB = machine.GPIO6
+)

src/examples/pwm/pico2.go

@@ -0,0 +1,11 @@
+//go:build pico2 || pico_plus2
+
+package main
+
+import "machine"
+
+var (
+	pwm = machine.PWM0 // Pin 25 (LED on pico2) corresponds to PWM0.
+	//pinA = machine.LED
+	pinA = machine.GPIO16
+)

src/examples/pwm/xiao_esp32s3.go

@@ -0,0 +1,11 @@
+//go:build xiao_esp32s3
+
+package main
+
+import "machine"
+
+var (
+	pwm  = machine.PWM0
+	pinA = machine.D0
+	pinB = machine.D1
+)

src/examples/serial-stress/main.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"machine"
+	"strconv"
+	"time"
+)
+
+func main() {
+	time.Sleep(2 * time.Second) // connect via serial
+	buf1 := makeBuffer('|', 600)
+	buf2 := makeBuffer('/', 600)
+	println("start")
+	serialWrite(buf1)
+	serialWrite(buf2)
+}
+
+func makeBuffer(sep byte, size int) []byte {
+	buf := make([]byte, size)
+	for i := 0; i < size-5; i += 5 {
+		buf[i] = sep
+		strconv.AppendInt(buf[i+1:i+1:i+5], int64(i), 10)
+	}
+	return buf
+}
+
+func serialWrite(b []byte) {
+	machine.Serial.Write(b)
+}

src/internal/abi/escape.go

@@ -15,3 +15,35 @@ func Escape[T any](x T) T {
 	// as-is.
 	panic("internal/abi.Escape: unreachable (implemented in the compiler)")
 }
+
+// EscapeNonString forces v to be on the heap, if v contains a
+// non-string pointer.
+//
+// This is used in hash/maphash.Comparable. We cannot hash pointers
+// to local variables on stack, as their addresses might change on
+// stack growth. Strings are okay as the hash depends on only the
+// content, not the pointer.
+//
+// This is essentially
+//
+//	if hasNonStringPointers(T) { Escape(v) }
+//
+// Implemented as a compiler intrinsic.
+func EscapeNonString[T any](v T) { panic("intrinsic") }
+
+// EscapeToResultNonString models a data flow edge from v to the result,
+// if v contains a non-string pointer. If v contains only string pointers,
+// it returns a copy of v, but is not modeled as a data flow edge
+// from the escape analysis's perspective.
+//
+// This is used in unique.clone, to model the data flow edge on the
+// value with strings excluded, because strings are cloned (by
+// content).
+//
+// TODO: probably we should define this as a intrinsic and EscapeNonString
+// could just be "heap = EscapeToResultNonString(v)". This way we can model
+// an edge to the result but not necessarily heap.
+func EscapeToResultNonString[T any](v T) T {
+	EscapeNonString(v)
+	return *(*T)(NoEscape(unsafe.Pointer(&v)))
+}

src/internal/itoa/itoa.go

@@ -0,0 +1,57 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Simple conversions to avoid depending on strconv.
+
+package itoa
+
+// Itoa converts val to a decimal string.
+func Itoa(val int) string {
+	if val < 0 {
+		return "-" + Uitoa(uint(-val))
+	}
+	return Uitoa(uint(val))
+}
+
+// Uitoa converts val to a decimal string.
+func Uitoa(val uint) string {
+	if val == 0 { // avoid string allocation
+		return "0"
+	}
+	var buf [20]byte // big enough for 64bit value base 10
+	i := len(buf) - 1
+	for val >= 10 {
+		q := val / 10
+		buf[i] = byte('0' + val - q*10)
+		i--
+		val = q
+	}
+	// val < 10
+	buf[i] = byte('0' + val)
+	return string(buf[i:])
+}
+
+const hex = "0123456789abcdef"
+
+// Uitox converts val (a uint) to a hexadecimal string.
+func Uitox(val uint) string {
+	if val == 0 { // avoid string allocation
+		return "0x0"
+	}
+	var buf [20]byte // big enough for 64bit value base 16 + 0x
+	i := len(buf) - 1
+	for val >= 16 {
+		q := val / 16
+		buf[i] = hex[val%16]
+		i--
+		val = q
+	}
+	// val < 16
+	buf[i] = hex[val%16]
+	i--
+	buf[i] = 'x'
+	i--
+	buf[i] = '0'
+	return string(buf[i:])
+}

src/internal/itoa/itoa_test.go

@@ -0,0 +1,51 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package itoa_test
+
+import (
+	"fmt"
+	"internal/itoa"
+	"math"
+	"testing"
+)
+
+var (
+	minInt64  int64  = math.MinInt64
+	maxInt64  int64  = math.MaxInt64
+	maxUint64 uint64 = math.MaxUint64
+)
+
+func TestItoa(t *testing.T) {
+	tests := []int{int(minInt64), math.MinInt32, -999, -100, -1, 0, 1, 100, 999, math.MaxInt32, int(maxInt64)}
+	for _, tt := range tests {
+		got := itoa.Itoa(tt)
+		want := fmt.Sprint(tt)
+		if want != got {
+			t.Fatalf("Itoa(%d) = %s, want %s", tt, got, want)
+		}
+	}
+}
+
+func TestUitoa(t *testing.T) {
+	tests := []uint{0, 1, 100, 999, math.MaxUint32, uint(maxUint64)}
+	for _, tt := range tests {
+		got := itoa.Uitoa(tt)
+		want := fmt.Sprint(tt)
+		if want != got {
+			t.Fatalf("Uitoa(%d) = %s, want %s", tt, got, want)
+		}
+	}
+}
+
+func TestUitox(t *testing.T) {
+	tests := []uint{0, 1, 15, 100, 999, math.MaxUint32, uint(maxUint64)}
+	for _, tt := range tests {
+		got := itoa.Uitox(tt)
+		want := fmt.Sprintf("%#x", tt)
+		if want != got {
+			t.Fatalf("Uitox(%x) = %s, want %s", tt, got, want)
+		}
+	}
+}

src/internal/reflectlite/type.go

@@ -157,6 +157,10 @@ const (
 	flagIsBinary   = 128 // flag that is set if this type uses the hashmap binary algorithm
 )
 
+// Flag in the numMethod field (uint16) of Pointer and Struct type descriptors,
+// indicating that an inline method set is present in the type descriptor.
+const numMethodHasMethodSet = 0x8000
+
 // The base type struct. All type structs start with this.
 type RawType struct {
 	meta uint8 // metadata byte, contains kind and flags (see constants above)
@@ -171,16 +175,22 @@ type elemType struct {
 	elem      *RawType
 }
 
+// ptrType is the type descriptor for pointer types.
+// The numMethod field stores the number of exported methods in the lower bits,
+// with bit 15 (numMethodHasMethodSet) indicating whether the methods field is
+// present. When the flag is clear, the methods field does not exist in the
+// actual type descriptor and must not be accessed.
 type ptrType struct {
 	RawType
 	numMethod uint16
 	elem      *RawType
+	methods   methodSet // only present when numMethod & numMethodHasMethodSet != 0
 }
 
 type interfaceType struct {
 	RawType
-	ptrTo *RawType
-	// TODO: methods
+	ptrTo   *RawType
+	methods methodSet
 }
 
 type arrayType struct {
@@ -200,13 +210,19 @@ type mapType struct {
 	key       *RawType
 }
 
+// namedType is the type descriptor for named types. The numMethod field uses
+// bit 15 (numMethodHasMethodSet) to indicate whether an inline method set is
+// present after pkg. When the flag is set, a methodSet follows at
+// unsafe.Sizeof(namedType{}), and the name string follows after the method
+// set's entries. When clear, the name string starts directly at that offset.
 type namedType struct {
 	RawType
 	numMethod uint16
 	ptrTo     *RawType
 	elem      *RawType
 	pkg       *byte
-	name      [1]byte
+	// if numMethod & numMethodHasMethodSet != 0: methodSet follows here
+	// name (null-terminated "pkg.Name\0") follows after the method set (or directly here)
 }
 
 // Type for struct types. The numField value is intentionally put before ptrTo
@@ -216,6 +232,10 @@ type namedType struct {
 // The fields array isn't necessarily 1 structField long, instead it is as long
 // as numFields. The array is given a length of 1 to satisfy the Go type
 // checker.
+// The numMethod field stores the number of exported methods in the lower bits,
+// with bit 15 (numMethodHasMethodSet) indicating whether an inline method set
+// follows the fields array. When the flag is clear, no method set is present
+// and the type descriptor ends after the last structField entry.
 type structType struct {
 	RawType
 	numMethod uint16
@@ -224,6 +244,7 @@ type structType struct {
 	size      uint32
 	numField  uint16
 	fields    [1]structField // the remaining fields are all of type structField
+	// methods methodSet follows after fields, only when numMethod & numMethodHasMethodSet != 0
 }
 
 type structField struct {
@@ -231,6 +252,12 @@ type structField struct {
 	data      unsafe.Pointer // various bits of information, packed in a byte array
 }
 
+// Method set, as emitted by the compiler.
+type methodSet struct {
+	length  uintptr
+	methods [0]unsafe.Pointer // variable number of method signature pointers
+}
+
 // Equivalent to (go/types.Type).Underlying(): if this is a named type return
 // the underlying type, else just return the type itself.
 func (t *RawType) underlying() *RawType {
@@ -733,21 +760,38 @@ func (t *RawType) FieldAlign() int {
 // AssignableTo returns whether a value of type t can be assigned to a variable
 // of type u.
 func (t *RawType) AssignableTo(u Type) bool {
-	if t == u.(*RawType) {
-		return true
-	}
-
-	if t.underlying() == u.(*RawType).underlying() && (!t.isNamed() || !u.(*RawType).isNamed()) {
-		return true
-	}
-
-	if u.Kind() == Interface && u.NumMethod() == 0 {
+	u_raw := u.(*RawType)
+	if t == u_raw {
 		return true
 	}
 
 	if u.Kind() == Interface {
-		panic("reflect: unimplemented: AssignableTo with interface")
+		// T is an interface type and x implements T.
+		u_itf := (*interfaceType)(unsafe.Pointer(u_raw.underlying()))
+		return typeImplementsMethodSet(unsafe.Pointer(t), unsafe.Pointer(&u_itf.methods))
 	}
+
+	t_named := t.isNamed()
+	u_named := u_raw.isNamed()
+	if t_named && u_named {
+		return false
+	}
+	if t.underlying() == u_raw.underlying() {
+		return true
+	}
+
+	if t.Kind() == Chan && u_raw.Kind() == Chan {
+		t_chan := (*elemType)(unsafe.Pointer(t.underlying()))
+		u_chan := (*elemType)(unsafe.Pointer(u_raw.underlying()))
+		if t_chan.elem != u_chan.elem {
+			return false
+		}
+		if t_chan.ChanDir() != BothDir {
+			return false
+		}
+		return true
+	}
+
 	return false
 }
 
@@ -755,7 +799,85 @@ func (t *RawType) Implements(u Type) bool {
 	if u.Kind() != Interface {
 		panic("reflect: non-interface type passed to Type.Implements")
 	}
-	return t.AssignableTo(u)
+	u_itf := (*interfaceType)(unsafe.Pointer(u.(*RawType).underlying()))
+	return typeImplementsMethodSet(unsafe.Pointer(t), unsafe.Pointer(&u_itf.methods))
+}
+
+// typeImplementsMethodSet checks whether the concrete type (identified by its
+// typecode pointer) implements the given method set. Both the concrete type's
+// method set and the asserted method set are sorted arrays of method signature
+// pointers, so comparison is O(n+m).
+//
+//go:linkname typeImplementsMethodSet runtime.typeImplementsMethodSet
+func typeImplementsMethodSet(concreteType, assertedMethodSet unsafe.Pointer) bool {
+	if concreteType == nil {
+		return false
+	}
+
+	const ptrSize = unsafe.Sizeof((*byte)(nil))
+	itfNumMethod := *(*uintptr)(assertedMethodSet)
+	if itfNumMethod == 0 {
+		return true
+	}
+
+	// Pull the method set out of the concrete type.
+	var methods *methodSet
+	metaByte := *(*uint8)(concreteType)
+	if metaByte&flagNamed != 0 {
+		ct := (*namedType)(concreteType)
+		if ct.numMethod&numMethodHasMethodSet == 0 {
+			return false
+		}
+		methods = (*methodSet)(unsafe.Add(unsafe.Pointer(ct), unsafe.Sizeof(*ct)))
+	} else if metaByte&kindMask == uint8(Interface) {
+		ct := (*interfaceType)(concreteType)
+		methods = &ct.methods
+	} else if metaByte&kindMask == uint8(Pointer) {
+		ct := (*ptrType)(concreteType)
+		if ct.numMethod&numMethodHasMethodSet == 0 {
+			return false
+		}
+		methods = &ct.methods
+	} else if metaByte&kindMask == uint8(Struct) {
+		ct := (*structType)(concreteType)
+		if ct.numMethod&numMethodHasMethodSet == 0 {
+			return false
+		}
+		// For struct types, the method set follows after the variable-length
+		// fields array. We need to compute its offset dynamically.
+		fieldSize := unsafe.Sizeof(structField{})
+		methodsPtr := unsafe.Add(unsafe.Pointer(&ct.fields[0]), uintptr(ct.numField)*fieldSize)
+		methods = (*methodSet)(methodsPtr)
+	} else {
+		return false
+	}
+
+	concreteTypePtr := unsafe.Pointer(&methods.methods)
+	concreteTypeEnd := unsafe.Add(concreteTypePtr, uintptr(methods.length)*ptrSize)
+
+	// Iterate over each method in the interface method set, and check whether
+	// the method exists in the method set of the concrete type.
+	// Both method sets are sorted, so we can use a linear scan.
+	assertedTypePtr := unsafe.Add(assertedMethodSet, ptrSize)
+	assertedTypeEnd := unsafe.Add(assertedTypePtr, itfNumMethod*ptrSize)
+	for assertedTypePtr != assertedTypeEnd {
+		assertedMethod := *(*unsafe.Pointer)(assertedTypePtr)
+
+		for {
+			if concreteTypePtr == concreteTypeEnd {
+				return false
+			}
+			concreteMethod := *(*unsafe.Pointer)(concreteTypePtr)
+			concreteTypePtr = unsafe.Add(concreteTypePtr, ptrSize)
+			if concreteMethod == assertedMethod {
+				break
+			}
+		}
+
+		assertedTypePtr = unsafe.Add(assertedTypePtr, ptrSize)
+	}
+
+	return true
 }
 
 // Comparable returns whether values of this type can be compared to each other.
@@ -782,14 +904,14 @@ func (t *RawType) ChanDir() ChanDir {
 func (t *RawType) NumMethod() int {
 
 	if t.isNamed() {
-		return int((*namedType)(unsafe.Pointer(t)).numMethod)
+		return int((*namedType)(unsafe.Pointer(t)).numMethod & ^uint16(numMethodHasMethodSet))
 	}
 
 	switch t.Kind() {
 	case Pointer:
-		return int((*ptrType)(unsafe.Pointer(t)).numMethod)
+		return int((*ptrType)(unsafe.Pointer(t)).numMethod & ^uint16(numMethodHasMethodSet))
 	case Struct:
-		return int((*structType)(unsafe.Pointer(t)).numMethod)
+		return int((*structType)(unsafe.Pointer(t)).numMethod & ^uint16(numMethodHasMethodSet))
 	case Interface:
 		//FIXME: Use len(methods)
 		return (*interfaceType)(unsafe.Pointer(t)).ptrTo.NumMethod()
@@ -816,7 +938,14 @@ func readStringZ(data unsafe.Pointer) string {
 
 func (t *RawType) name() string {
 	ntype := (*namedType)(unsafe.Pointer(t))
-	return readStringZ(unsafe.Pointer(&ntype.name[0]))
+	// The name follows after the fixed fields (and optionally the method set).
+	ptr := unsafe.Add(unsafe.Pointer(ntype), unsafe.Sizeof(*ntype))
+	if ntype.numMethod&numMethodHasMethodSet != 0 {
+		ms := (*methodSet)(ptr)
+		// Skip past the length field and the method pointer entries.
+		ptr = unsafe.Add(ptr, unsafe.Sizeof(uintptr(0))+uintptr(ms.length)*unsafe.Sizeof(unsafe.Pointer(nil)))
+	}
+	return readStringZ(ptr)
 }
 
 func (t *RawType) Name() string {

src/internal/reflectlite/value.go

@@ -138,7 +138,7 @@ func TypeAssert[T any](v Value) (T, bool) {
 		var zero T
 		return zero, false
 	}
-	if !v.isIndirect() {
+	if !v.isIndirect() && v.typecode.Size() <= unsafe.Sizeof(uintptr(0)) {
 		return *(*T)(unsafe.Pointer(&v.value)), true
 	}
 	return *(*T)(v.value), true

src/internal/syscall/unix/getrandom.go

@@ -1,5 +1,9 @@
+//go:build !tinygo.wasm
+
 package unix
 
+import "syscall"
+
 type GetRandomFlag uintptr
 
 const (
@@ -8,5 +12,7 @@ const (
 )
 
 func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
-	panic("todo: unix.GetRandom")
+	// Not supported on most TinyGo targets.
+	// On real Linux the sysrand package will fall back to /dev/urandom.
+	return 0, syscall.ENOSYS
 }

src/internal/syscall/unix/getrandom_wasi.go

@@ -0,0 +1,25 @@
+//go:build tinygo.wasm
+
+package unix
+
+import "unsafe"
+
+type GetRandomFlag uintptr
+
+const (
+	GRND_NONBLOCK GetRandomFlag = 0x0001
+	GRND_RANDOM   GetRandomFlag = 0x0002
+)
+
+func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
+	if len(p) == 0 {
+		return 0, nil
+	}
+	libc_arc4random_buf(unsafe.Pointer(&p[0]), uint(len(p)))
+	return len(p), nil
+}
+
+// void arc4random_buf(void *buf, size_t buflen);
+//
+//export arc4random_buf
+func libc_arc4random_buf(buf unsafe.Pointer, buflen uint)

src/internal/task/task.go

@@ -22,7 +22,8 @@ type Task struct {
 	state state
 
 	// This is needed for some crypto packages.
-	FipsIndicator uint8
+	FipsIndicator  uint8
+	FipsOnlyBypass bool
 
 	// State of the goroutine: running, paused, or must-resume-next-pause.
 	// This extra field doesn't increase memory usage on 32-bit CPUs and above,

src/internal/task/task_stack_esp32.S

@@ -46,26 +46,40 @@ tinygo_swapTask:
     // arbitrary register while registers are flushed.
     rsil a4, 3 // XCHAL_EXCM_LEVEL
 
-    // Flush all unsaved registers to the stack.
-    // This trick has been borrowed from the Zephyr project:
-    // https://github.com/zephyrproject-rtos/zephyr/blob/d79b003758/arch/xtensa/include/xtensa-asm2-s.h#L17
-    and a12, a12, a12
-    rotw 3
-    and a12, a12, a12
-    rotw 3
-    and a12, a12, a12
-    rotw 3
-    and a12, a12, a12
-    rotw 3
-    and a12, a12, a12
-    rotw 4
+    // Save the old PS (in a4) to the stack because call4 clobbers a4-a7.
+    s32i a4, sp, 4
+
+    // Flush all register windows to the stack using recursive call4.
+    //
+    // The previous ROTW-based approach (borrowed from Zephyr) does NOT
+    // actually trigger window overflow exceptions on Xtensa LX7 — ROTW
+    // simply modifies WindowBase without saving any registers to the stack.
+    // This leaves stale window data in the physical register file after a
+    // goroutine switch, corrupting the overflow save chain when the new
+    // goroutine's deeper calls trigger overflow of old goroutine windows.
+    //
+    // Instead, we recursively call a small function via call4.  Each call4 +
+    // entry triggers the hardware window-overflow mechanism for any occupied
+    // pane being reused, correctly saving registers to the stack.
+    // For NAREG=64 (16 panes), 15 recursive levels cover all panes except
+    // the current one (tinygo_swapTask), which must stay active.
+    movi a6, 15
+    call4 .Lspill_windows
+
+    // After the recursive spill returns, the physical register file still
+    // has WindowStart bits set for the spill helper frames.
+    // We will clear WindowStart completely (to 0) right before the retw.n
+    // below, after the stack switch is done.  This prevents stale overflow
+    // when the new goroutine's calls rotate back into these panes.
 
     // Restore interrupts.
+    l32i a4, sp, 4          // reload saved PS
     wsr.ps a4
+    rsync
 
     // At this point, the following is true:
     //     WindowStart == 1 << WindowBase
-    // Therefore, we don't need to do this manually.
+    // All other windows have been properly flushed to their stacks.
     // It also means that the stack pointer can now be safely modified.
 
     // Save a0, which stores the return address and the parent register window
@@ -83,6 +97,30 @@ tinygo_swapTask:
     // register also stores the parent register window.
     l32i.n a0, sp, 0
 
+    // Clear ALL WindowStart bits.  With all windows spilled to the stack,
+    // we must ensure no stale WS bits remain: the retw.n below will trigger
+    // underflow4 to load the new goroutine's registers from the new stack
+    // (which sets the appropriate WS bit via rfwu).  Any stale WS bits
+    // (from spill helpers or the old goroutine) would cause spurious
+    // overflows of garbage register values into memory.
+    movi a5, 0
+    wsr  a5, WINDOWSTART
+    rsync
+
     // Return into the new stack. This instruction will trigger a window
     // underflow, reloading the saved registers from the stack.
     retw.n
+
+// Recursive helper for flushing all register windows.
+// Parameter: a2 = remaining recursion depth (passed via caller's a6).
+// Each call4 + entry triggers the hardware overflow mechanism for any
+// occupied pane at the new WindowBase position.
+    .balign 4
+.Lspill_windows:
+    entry a1, 16
+    beqz  a2, .Lspill_done
+    addi  a2, a2, -1
+    mov   a6, a2
+    call4 .Lspill_windows
+.Lspill_done:
+    retw.n

src/internal/task/task_stack_esp32.go

@@ -74,3 +74,8 @@ func (s *state) pause() {
 func SystemStack() uintptr {
 	return systemStack
 }
+
+//export tinygo_task_current
+func tinygo_task_current() unsafe.Pointer {
+	return unsafe.Pointer(Current())
+}

src/internal/task/task_stack_tinygoriscv.go

@@ -71,3 +71,8 @@ func (s *state) pause() {
 func SystemStack() uintptr {
 	return *runtime_systemStackPtr()
 }
+
+//export tinygo_task_current
+func tinygo_task_current() unsafe.Pointer {
+	return unsafe.Pointer(Current())
+}

src/machine/board_arduino_uno.go

@@ -1,4 +1,4 @@
-//go:build arduino
+//go:build arduino_uno
 
 package machine
 

src/machine/board_arduino_uno_q.go

@@ -0,0 +1,134 @@
+//go:build arduino_uno_q
+
+// Arduino UNO Q board with STM32U585 processor.
+
+package machine
+
+import (
+	"device/stm32"
+	"runtime/interrupt"
+	"unsafe"
+)
+
+const (
+	// Arduino Pins
+	A0 = PA4
+	A1 = PA5
+	A2 = PA6
+	A3 = PA7
+	A4 = PC1
+	A5 = PC0
+
+	// ADC pin aliases
+	ADC0 = A0
+	ADC1 = A1
+	ADC2 = A2
+	ADC3 = A3
+	ADC4 = A4
+	ADC5 = A5
+
+	D0  = PB7 // USART1 RX, PWM TIM4_CH2
+	D1  = PB6 // USART1 TX, PWM TIM4_CH1
+	D2  = PB3 // PWM TIM2_CH2
+	D3  = PB0 // PWM TIM3_CH3
+	D4  = PA12
+	D5  = PA11 // PWM TIM1_CH4
+	D6  = PB1  // PWM TIM3_CH4
+	D7  = PB2
+	D8  = PB4  // PWM TIM3_CH1
+	D9  = PB8  // PWM TIM4_CH3 / TIM16_CH1
+	D10 = PB9  // PWM TIM4_CH4 / TIM17_CH1
+	D11 = PB15 // PWM TIM15_CH2
+	D12 = PB14 // PWM TIM15_CH1
+	D13 = PB13
+	D18 = PC1
+	D19 = PC0
+	D20 = PB10 // I2C2 SCL, PWM TIM2_CH3
+	D21 = PB11 // I2C2 SDA, PWM TIM2_CH4
+)
+
+const (
+	LED    = LED3_R
+	LED3_R = PH10
+	LED3_G = PH11
+	LED3_B = PH12
+	LED4_R = PH13
+	LED4_G = PH14
+	LED4_B = PH15
+)
+
+const (
+	// Default UART pins (LPUART1 active via ST-LINK virtual COM port)
+	UART_TX_PIN = PG7
+	UART_RX_PIN = PG8
+
+	// USART1 pins (Arduino header D1/D0)
+	UART1_TX_PIN = D1
+	UART1_RX_PIN = D0
+
+	// LPUART1 pins (active via ST-LINK virtual COM port)
+	UART2_TX_PIN = PG7
+	UART2_RX_PIN = PG8
+
+	// I2C pins, also connected to I2C2
+	I2C0_SCL_PIN = D20
+	I2C0_SDA_PIN = D21
+	// QWIIC connector pins, also connected to I2C4
+	I2C1_SCL_PIN = PD12
+	I2C1_SDA_PIN = PD13
+
+	// SPI pins
+	SPI1_SCK_PIN = PA5
+	SPI1_SDI_PIN = PA6
+	SPI1_SDO_PIN = PA7
+	SPI0_SCK_PIN = SPI1_SCK_PIN
+	SPI0_SDI_PIN = SPI1_SDI_PIN
+	SPI0_SDO_PIN = SPI1_SDO_PIN
+)
+
+var (
+	// USART1 on PB6/PB7 (Arduino header D1/D0).
+	UART1  = &_UART1
+	_UART1 = UART{
+		Buffer:            NewRingBuffer(),
+		Bus:               stm32.USART1,
+		TxAltFuncSelector: AF7_USART1_2_3,
+		RxAltFuncSelector: AF7_USART1_2_3,
+	}
+
+	// LPUART1 on PG7/PG8 (active via ST-LINK virtual COM port).
+	UART2  = &_UART2
+	_UART2 = UART{
+		Buffer:            NewRingBuffer(),
+		Bus:               (*stm32.USART_Type)(unsafe.Pointer(stm32.LPUART1)),
+		TxAltFuncSelector: AF8_UART4_5_LPUART1_SDMMC1,
+		RxAltFuncSelector: AF8_UART4_5_LPUART1_SDMMC1,
+	}
+	DefaultUART = UART2
+
+	// I2C2 is documented, alias to I2C0 as well
+	I2C2 = &I2C{
+		Bus:             stm32.I2C2,
+		AltFuncSelector: AF4_I2C1_2_3_4,
+	}
+	I2C0 = I2C2
+
+	// I2C4 is is connected to the QWIIC connector, alias to I2C1 as well
+	I2C4 = &I2C{
+		Bus:             stm32.I2C4,
+		AltFuncSelector: AF4_I2C1_2_3_4,
+	}
+	I2C1 = I2C4
+
+	// SPI1 is documented, alias to SPI0 as well
+	SPI1 = &SPI{
+		Bus:             stm32.SPI1,
+		AltFuncSelector: AF5_SPI1_2_3_OCTOSPI1_OCTOSPI2,
+	}
+	SPI0 = SPI1
+)
+
+func init() {
+	UART1.Interrupt = interrupt.New(stm32.IRQ_USART1, _UART1.handleInterrupt)
+	UART2.Interrupt = interrupt.New(stm32.IRQ_LPUART1, _UART2.handleInterrupt)
+}

src/machine/board_atmega328p.go

@@ -1,4 +1,4 @@
-//go:build (avr && atmega328p) || arduino || arduino_nano
+//go:build (avr && atmega328p) || arduino_uno || arduino_nano
 
 package machine
 

src/machine/board_esp32-generic.go

@@ -0,0 +1,9 @@
+//go:build esp32_generic
+
+package machine
+
+// I2C pins
+const (
+	SDA_PIN = NoPin
+	SCL_PIN = NoPin
+)

src/machine/board_esp32c3-12f.go

@@ -30,9 +30,6 @@ const (
 
 // ADC pins
 const (
-	ADC0 Pin = ADC1_0
-	ADC1 Pin = ADC2_0
-
 	ADC1_0 Pin = IO0
 	ADC1_1 Pin = IO1
 	ADC1_2 Pin = IO2

src/machine/board_esp32c3-generic.go

@@ -0,0 +1,8 @@
+//go:build esp32c3_generic
+
+package machine
+
+const (
+	SDA_PIN = NoPin
+	SCL_PIN = NoPin
+)

src/machine/board_esp32c3-supermini.go

@@ -1,6 +1,6 @@
 //go:build esp32c3_supermini
 
-// This file contains the pin mappings for the ESP32 supermini boards.
+// This file contains the pin mappings for the ESP32C3 supermini board.
 //
 // - https://web.archive.org/web/20240805232453/https://dl.artronshop.co.th/ESP32-C3%20SuperMini%20datasheet.pdf
 

src/machine/board_esp32s3-generic.go

@@ -0,0 +1,18 @@
+//go:build esp32s3_generic
+
+package machine
+
+const (
+	SCL_PIN = NoPin
+	SDA_PIN = NoPin
+
+	SPI1_SCK_PIN  = NoPin // SCK
+	SPI1_MOSI_PIN = NoPin // SDO (MOSI)
+	SPI1_MISO_PIN = NoPin // SDI (MISO)
+	SPI1_CS_PIN   = NoPin // CS
+
+	SPI2_SCK_PIN  = NoPin // SCK
+	SPI2_MOSI_PIN = NoPin // SDO (MOSI)
+	SPI2_MISO_PIN = NoPin // SDI (MISO)
+	SPI2_CS_PIN   = NoPin // CS
+)

src/machine/board_esp32s3-supermini.go

@@ -0,0 +1,88 @@
+//go:build esp32s3_supermini
+
+// This file contains the pin mappings for the ESP32S3 supermini board.
+//
+// - https://www.nologo.tech/product/esp32/esp32s3/esp32s3supermini/esp32S3SuperMini.html
+
+package machine
+
+// Digital Pins
+const (
+	IO1  = GPIO1
+	IO2  = GPIO2
+	IO3  = GPIO3
+	IO4  = GPIO4
+	IO5  = GPIO5
+	IO6  = GPIO6
+	IO7  = GPIO7
+	IO8  = GPIO8
+	IO9  = GPIO9
+	IO10 = GPIO10
+	IO11 = GPIO11
+	IO12 = GPIO12
+	IO13 = GPIO13
+	IO14 = GPIO14
+	IO15 = GPIO15
+	IO16 = GPIO16
+	IO17 = GPIO17
+	IO18 = GPIO18
+	IO21 = GPIO21
+	IO33 = GPIO33
+	IO34 = GPIO34
+	IO35 = GPIO35
+	IO36 = GPIO36
+	IO37 = GPIO37
+	IO38 = GPIO38
+	IO39 = GPIO39
+	IO40 = GPIO40
+	IO41 = GPIO41
+	IO42 = GPIO42
+	IO43 = GPIO43
+	IO44 = GPIO44
+	IO45 = GPIO45
+	IO46 = GPIO46
+	IO47 = GPIO47
+	IO48 = GPIO48
+)
+
+// Built-in LED
+const LED = GPIO48
+
+// Analog pins
+const (
+	A1  = GPIO1
+	A2  = GPIO2
+	A3  = GPIO3
+	A4  = GPIO4
+	A5  = GPIO5
+	A6  = GPIO6
+	A7  = GPIO7
+	A8  = GPIO8
+	A9  = GPIO9
+	A10 = GPIO10
+	A11 = GPIO11
+	A12 = GPIO12
+	A13 = GPIO13
+	A14 = GPIO14
+	A15 = GPIO15
+	A16 = GPIO16
+)
+
+// I2C pins
+const (
+	SDA_PIN = GPIO8
+	SCL_PIN = GPIO9
+)
+
+// SPI pins
+const (
+	SPI1_SCK_PIN  = GPIO4
+	SPI1_MISO_PIN = GPIO5
+	SPI1_MOSI_PIN = GPIO6
+	SPI1_CS_PIN   = GPIO7
+
+	SPI2_SCK_PIN  = NoPin
+	SPI2_MOSI_PIN = NoPin
+	SPI2_MISO_PIN = NoPin
+	SPI2_CS_PIN   = NoPin
+)

src/machine/board_esp32s3-wroom1.go

@@ -1,15 +0,0 @@
-//go:build esp32s3_wroom1
-
-package machine
-
-const (
-	SPI1_SCK_PIN  = GPIO12 // SCK
-	SPI1_MOSI_PIN = GPIO11 // SDO (MOSI)
-	SPI1_MISO_PIN = GPIO13 // SDI (MISO)
-	SPI1_CS_PIN   = GPIO10 // CS
-
-	SPI2_SCK_PIN  = GPIO36 // SCK
-	SPI2_MOSI_PIN = GPIO35 // SDO (MOSI)
-	SPI2_MISO_PIN = GPIO37 // SDI (MISO)
-	SPI2_CS_PIN   = GPIO34 // CS
-)

src/machine/board_xiao-rp2350.go

@@ -0,0 +1,93 @@
+//go:build xiao_rp2350
+
+// This file contains the pin mappings for the Seeed XIAO RP2350 boards.
+//
+// XIAO RP2350 is a microcontroller using the Raspberry Pi RP2350 chip.
+//
+// - https://wiki.seeedstudio.com/XIAO-RP2350/
+package machine
+
+// Digital Pins
+const (
+	D0  Pin = GPIO26
+	D1  Pin = GPIO27
+	D2  Pin = GPIO28
+	D3  Pin = GPIO5
+	D4  Pin = GPIO6
+	D5  Pin = GPIO7
+	D6  Pin = GPIO0
+	D7  Pin = GPIO1
+	D8  Pin = GPIO2
+	D9  Pin = GPIO4
+	D10 Pin = GPIO3
+	D11 Pin = GPIO21
+	D12 Pin = GPIO20
+	D13 Pin = GPIO17
+	D14 Pin = GPIO16
+	D15 Pin = GPIO11
+	D16 Pin = GPIO12
+	D17 Pin = GPIO10
+)
+
+// Analog pins
+const (
+	A0 Pin = D0
+	A1 Pin = D1
+	A2 Pin = D2
+)
+
+// Onboard LEDs
+const (
+	NEOPIXEL       = GPIO22
+	WS2812         = GPIO22
+	NEO_PWR        = GPIO23
+	NEOPIXEL_POWER = GPIO23
+
+	LED = GPIO25
+)
+
+// I2C pins
+const (
+	I2C0_SDA_PIN Pin = D14
+	I2C0_SCL_PIN Pin = D13
+
+	I2C1_SDA_PIN Pin = D4
+	I2C1_SCL_PIN Pin = D5
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN Pin = D8
+	SPI0_SDO_PIN Pin = D10
+	SPI0_SDI_PIN Pin = D9
+
+	SPI1_SCK_PIN Pin = D17
+	SPI1_SDO_PIN Pin = D15
+	SPI1_SDI_PIN Pin = D16
+)
+
+// Onboard crystal oscillator frequency, in MHz.
+const (
+	xoscFreq = 12 // MHz
+)
+
+// UART pins
+const (
+	UART0_TX_PIN = GPIO0
+	UART0_RX_PIN = GPIO1
+	UART_TX_PIN  = UART0_TX_PIN
+	UART_RX_PIN  = UART0_RX_PIN
+)
+
+var DefaultUART = UART0
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "XIAO RP2350"
+	usb_STRING_MANUFACTURER = "Seeed"
+)
+
+var (
+	usb_VID uint16 = 0x2e8a
+	usb_PID uint16 = 0x000a
+)

src/machine/flash.go

@@ -1,4 +1,4 @@
-//go:build nrf || nrf51 || nrf52 || nrf528xx || stm32f4 || stm32l0 || stm32l4 || stm32wlx || atsamd21 || atsamd51 || atsame5x || rp2040 || rp2350
+//go:build esp32c3 || nrf || nrf51 || nrf52 || nrf528xx || stm32f4 || stm32l0 || stm32l4 || stm32wlx || atsamd21 || atsamd51 || atsame5x || rp2040 || rp2350
 
 package machine
 

src/machine/i2c.go

@@ -1,4 +1,4 @@
-//go:build !baremetal || atmega || nrf || sam || stm32 || fe310 || k210 || rp2040 || rp2350 || mimxrt1062 || (esp32c3 && !m5stamp_c3) || esp32
+//go:build !baremetal || atmega || nrf || sam || stm32 || fe310 || k210 || rp2040 || rp2350 || mimxrt1062 || (esp32c3 && !m5stamp_c3) || esp32 || esp32s3
 
 package machine
 

src/machine/machine_atmega328p_simulator.go

@@ -1,4 +1,4 @@
-//go:build !baremetal && (arduino || arduino_nano)
+//go:build !baremetal && (arduino_uno || arduino_nano)
 
 package machine
 

src/machine/machine_atsamd51.go

@@ -11,6 +11,7 @@ import (
 	"device/sam"
 	"errors"
 	"internal/binary"
+
 	"runtime/interrupt"
 	"unsafe"
 )

src/machine/machine_esp32c3.go

@@ -27,16 +27,29 @@ const (
 	PinInput
 	PinInputPullup
 	PinInputPulldown
+	PinAnalog
+)
+
+const (
+	GPIO0 Pin = 0
+	GPIO1 Pin = 1
+	GPIO2 Pin = 2
+	GPIO3 Pin = 3
+	GPIO4 Pin = 4
+	GPIO5 Pin = 5
+	GPIO6 Pin = 6
+)
+
+const (
+	ADC0 Pin = GPIO0
+	ADC1 Pin = GPIO1
+	ADC2 Pin = GPIO2
+	ADC3 Pin = GPIO3
+	ADC4 Pin = GPIO4
+	ADC5 Pin = GPIO5 // avoid when WiFi is used.
 )
 
 const (
-	GPIO0  Pin = 0
-	GPIO1  Pin = 1
-	GPIO2  Pin = 2
-	GPIO3  Pin = 3
-	GPIO4  Pin = 4
-	GPIO5  Pin = 5
-	GPIO6  Pin = 6
 	GPIO7  Pin = 7
 	GPIO8  Pin = 8
 	GPIO9  Pin = 9
@@ -76,13 +89,15 @@ func (p Pin) Configure(config PinConfig) {
 	const function = 1 // function 1 is GPIO for every pin
 	muxConfig |= function << esp.IO_MUX_GPIO_MCU_SEL_Pos
 
-	// Make this pin an input pin (always).
-	muxConfig |= esp.IO_MUX_GPIO_FUN_IE
+	// FUN_IE: disable for PinAnalog (high-Z for ADC)
+	if config.Mode != PinAnalog {
+		muxConfig |= esp.IO_MUX_GPIO_FUN_IE
+	}
 
 	// Set drive strength: 0 is lowest, 3 is highest.
 	muxConfig |= 2 << esp.IO_MUX_GPIO_FUN_DRV_Pos
 
-	// Select pull mode.
+	// Select pull mode (no pulls for PinAnalog).
 	if config.Mode == PinInputPullup {
 		muxConfig |= esp.IO_MUX_GPIO_FUN_WPU
 	} else if config.Mode == PinInputPulldown {
@@ -99,12 +114,27 @@ func (p Pin) Configure(config PinConfig) {
 	case PinOutput:
 		// Set the 'output enable' bit.
 		esp.GPIO.ENABLE_W1TS.Set(1 << p)
-	case PinInput, PinInputPullup, PinInputPulldown:
+	case PinInput, PinInputPullup, PinInputPulldown, PinAnalog:
 		// Clear the 'output enable' bit.
 		esp.GPIO.ENABLE_W1TC.Set(1 << p)
 	}
 }
 
+// configure is the same as Configure, but allows setting a specific GPIO matrix signal.
+func (p Pin) configure(config PinConfig, signal uint32) {
+	p.Configure(config)
+	if signal == 256 {
+		return
+	}
+	if config.Mode == PinOutput {
+		p.outFunc().Set(signal)
+	} else {
+		inFunc(signal).Set(esp.GPIO_FUNC_IN_SEL_CFG_SEL | uint32(p))
+	}
+}
+
+func initI2CExt1Clock() {}
+
 // outFunc returns the FUNCx_OUT_SEL_CFG register used for configuring the
 // output function selection.
 func (p Pin) outFunc() *volatile.Register32 {
@@ -231,13 +261,13 @@ func setupPinInterrupt() error {
 	esp.INTERRUPT_CORE0.GPIO_INTERRUPT_PRO_MAP.Set(cpuInterruptFromPin)
 	return interrupt.New(cpuInterruptFromPin, func(interrupt.Interrupt) {
 		status := esp.GPIO.STATUS.Get()
+		// Clear before processing so new edges during callbacks are not lost.
+		esp.GPIO.STATUS_W1TC.Set(status)
 		for i, mask := 0, uint32(1); i < maxPin; i, mask = i+1, mask<<1 {
 			if (status&mask) != 0 && pinCallbacks[i] != nil {
 				pinCallbacks[i](Pin(i))
 			}
 		}
-		// clear interrupt bit
-		esp.GPIO.STATUS_W1TC.SetBits(status)
 	}).Enable()
 }
 

src/machine/machine_esp32c3_adc.go

@@ -0,0 +1,205 @@
+//go:build esp32c3 && !m5stamp_c3
+
+package machine
+
+import (
+	"device/esp"
+	"errors"
+)
+
+// newRegI2C returns the regI2C configured for ESP32-C3: hostID=0, drefInit=1.
+func newRegI2C() regI2C { return regI2C{hostID: 0, drefInit: 1} }
+
+const (
+	// ADC attenuation values for ESP32-C3 APB_SARADC.
+	// 0 dB  : ~0 .. 1.1 V
+	// 11 dB : ~0 .. 3.3 V (matches typical VDD)
+	atten0dB  = 0
+	atten11dB = 3
+)
+
+func InitADC() {
+	esp.SYSTEM.SetPERIP_RST_EN0_APB_SARADC_RST(1)
+	esp.SYSTEM.SetPERIP_CLK_EN0_APB_SARADC_CLK_EN(1)
+	esp.SYSTEM.SetPERIP_RST_EN0_APB_SARADC_RST(0)
+
+	esp.RTC_CNTL.SetANA_CONF_SAR_I2C_PU(1)
+	esp.RTC_CNTL.SetSENSOR_CTRL_FORCE_XPD_SAR(1)
+	esp.APB_SARADC.SetCTRL_SARADC_XPD_SAR_FORCE(1)
+	esp.APB_SARADC.SetFSM_WAIT_SARADC_XPD_WAIT(8)
+	esp.APB_SARADC.SetFSM_WAIT_SARADC_RSTB_WAIT(8)
+	esp.APB_SARADC.SetFSM_WAIT_SARADC_STANDBY_WAIT(100)
+	esp.APB_SARADC.SetCLKM_CONF_CLK_SEL(2)
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_NUM(1)
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_B(0)
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_A(0)
+	esp.APB_SARADC.SetCLKM_CONF_CLK_EN(1)
+
+	adcSelfCalibrate()
+}
+
+// ESP32-C3: ADC1 = GPIO0–GPIO4 (ch 0–4), ADC2 = GPIO5 (ch 0). ADC2 shares with Wi‑Fi;
+// readings may be noisy when Wi‑Fi is active.
+func (a ADC) Configure(config ADCConfig) error {
+	if a.Pin > 5 {
+		return errors.New("invalid ADC pin for ESP32-C3")
+	}
+	a.Pin.Configure(PinConfig{Mode: PinAnalog})
+	return nil
+}
+
+func (a ADC) Get() uint16 {
+	if a.Pin > 5 {
+		return 0
+	}
+	adc1 := a.Pin <= 4
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_ATTEN(atten11dB)
+	esp.APB_SARADC.SetINT_CLR_APB_SARADC1_DONE_INT_CLR(1)
+	esp.APB_SARADC.SetINT_CLR_APB_SARADC2_DONE_INT_CLR(1)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(0)
+	var raw uint32
+	if adc1 {
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_CHANNEL(uint32(a.Pin))
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC1_ONETIME_SAMPLE(1)
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(1)
+		for esp.APB_SARADC.GetINT_RAW_APB_SARADC1_DONE_INT_RAW() == 0 {
+		}
+		raw = esp.APB_SARADC.GetSAR1DATA_STATUS_APB_SARADC1_DATA()
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(0)
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC1_ONETIME_SAMPLE(0)
+	} else {
+		// ADC2: GPIO5 = channel 0. Grant arbiter to ADC2 first, then set channel and start.
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC1_ONETIME_SAMPLE(0)
+		esp.APB_SARADC.SetARB_CTRL_ADC_ARB_APB_FORCE(1)
+		esp.APB_SARADC.SetARB_CTRL_ADC_ARB_GRANT_FORCE(1)
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_CHANNEL(8) // (1<<3)|0 for ADC2 channel 0
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC2_ONETIME_SAMPLE(1)
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(1)
+		for esp.APB_SARADC.GetINT_RAW_APB_SARADC2_DONE_INT_RAW() == 0 {
+		}
+		raw = esp.APB_SARADC.GetSAR2DATA_STATUS_APB_SARADC2_DATA()
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(0)
+		esp.APB_SARADC.SetONETIME_SAMPLE_SARADC2_ONETIME_SAMPLE(0)
+		esp.APB_SARADC.SetARB_CTRL_ADC_ARB_APB_FORCE(0)
+		esp.APB_SARADC.SetARB_CTRL_ADC_ARB_GRANT_FORCE(0)
+	}
+	return uint16(raw&0xfff) << 4
+}
+
+// adcSelfCalibration
+const (
+	adcCalTimesC3    = 15
+	adcCalRtcMagicC3 = uint32(0xADC1C401)
+	adcCalInitMinC3  = uint32(1000)
+	adcCalInitMaxC3  = uint32(4096)
+)
+
+// selfCalibrate sets ADC1/ADC2 init code from RTC or runs self-calibration (GND).
+// eFuse is not used: on ESP32-C3 the ADC calibration fields in BLK2 are often unprogrammed.
+func adcSelfCalibrate() {
+	reg := newRegI2C()
+	reg.sarEnable()
+
+	var adc1Code uint32
+	if saved, ok := restoreFromRTC(); ok {
+		adc1Code = saved
+	} else {
+		calSetupADC1()
+		reg.calibrationInit(0)
+		reg.calibrationPrepare(0)
+		adc1Code = reg.calibrateBinarySearch(0, adcCalTimesC3, readADC1)
+		if adc1Code < adcCalInitMinC3 {
+			adc1Code = adcCalInitMinC3
+		}
+		if adc1Code > adcCalInitMaxC3 {
+			adc1Code = adcCalInitMaxC3
+		}
+		saveToRTC(adc1Code)
+		reg.calibrationFinish(0)
+	}
+
+	applyADC1Code(reg, adc1Code)
+	applyADC2Code(reg, adc1Code)
+}
+
+// calSetupADC1 configures APB_SARADC for oneshot sampling on ADC1 channel 0
+// with fixed attenuation. This is used only during self‑calibration.
+func calSetupADC1() {
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_ATTEN(atten11dB)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_CHANNEL(0)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC1_ONETIME_SAMPLE(1)
+}
+
+// calSetupADC2 configures APB_SARADC for oneshot sampling on ADC2 (GPIO5, ch 0).
+// On C3, onetime_channel = (unit<<3)|channel → ADC2 ch0 = 8.
+func calSetupADC2() {
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_ATTEN(atten11dB)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_CHANNEL(8) // (1<<3)|0 for ADC2
+	esp.APB_SARADC.SetARB_CTRL_ADC_ARB_APB_FORCE(1)
+	esp.APB_SARADC.SetARB_CTRL_ADC_ARB_GRANT_FORCE(1)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC2_ONETIME_SAMPLE(1)
+}
+
+// readADC1 performs a single ADC1 conversion using the APB_SARADC
+// oneshot path and returns the raw 12‑bit result (0..4095).
+func readADC1() uint32 {
+	esp.APB_SARADC.SetINT_CLR_APB_SARADC1_DONE_INT_CLR(1)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(0)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(1)
+	for esp.APB_SARADC.GetINT_RAW_APB_SARADC1_DONE_INT_RAW() == 0 {
+	}
+	raw := esp.APB_SARADC.GetSAR1DATA_STATUS_APB_SARADC1_DATA() & 0xfff
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(0)
+	return uint32(raw)
+}
+
+// readADC2 performs a single ADC2 conversion and returns the raw 12‑bit result (0..4095).
+func readADC2() uint32 {
+	esp.APB_SARADC.SetINT_CLR_APB_SARADC2_DONE_INT_CLR(1)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(0)
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(1)
+	for esp.APB_SARADC.GetINT_RAW_APB_SARADC2_DONE_INT_RAW() == 0 {
+	}
+	raw := esp.APB_SARADC.GetSAR2DATA_STATUS_APB_SARADC2_DATA() & 0xfff
+	esp.APB_SARADC.SetONETIME_SAMPLE_SARADC_ONETIME_START(0)
+	esp.APB_SARADC.SetARB_CTRL_ADC_ARB_APB_FORCE(0)
+	esp.APB_SARADC.SetARB_CTRL_ADC_ARB_GRANT_FORCE(0)
+	return uint32(raw)
+}
+
+func restoreFromRTC() (uint32, bool) {
+	if esp.RTC_CNTL.GetSTORE0() != adcCalRtcMagicC3 {
+		return 0, false
+	}
+	code := esp.RTC_CNTL.GetSTORE1()
+	if code < adcCalInitMinC3 || code > adcCalInitMaxC3 {
+		return 0, false
+	}
+	return code, true
+}
+
+func saveToRTC(code uint32) {
+	if code < adcCalInitMinC3 || code > adcCalInitMaxC3 {
+		return
+	}
+	esp.RTC_CNTL.SetSTORE0(adcCalRtcMagicC3)
+	esp.RTC_CNTL.SetSTORE1(code)
+}
+
+// applyADC1Code sets ADC1 init code and finishes calibration.
+func applyADC1Code(reg regI2C, code uint32) {
+	calSetupADC1()
+	reg.calibrationInit(0)
+	reg.calibrationPrepare(0)
+	reg.setCalibrationParam(0, code)
+	reg.calibrationFinish(0)
+}
+
+// applyADC2Code sets ADC2 init code and finishes calibration. On C3 eFuse V1
+// there is no separate ADC2 calibration; IDF uses ADC1 init code for both units.
+func applyADC2Code(reg regI2C, code uint32) {
+	reg.calibrationInit(1)
+	reg.calibrationPrepare(1)
+	reg.setCalibrationParam(1, code)
+	reg.calibrationFinish(1)
+}

src/machine/machine_esp32c3_flash.go

@@ -0,0 +1,137 @@
+//go:build esp32c3
+
+package machine
+
+import (
+	"runtime/interrupt"
+	"unsafe"
+)
+
+/*
+#include <stdint.h>
+extern int esp_rom_spiflash_read(uint32_t src_addr, uint32_t *data, uint32_t len);
+extern int esp_rom_spiflash_write(uint32_t dest_addr, const uint32_t *data, uint32_t len);
+extern int esp_rom_spiflash_erase_sector(uint32_t sector_num);
+extern int esp_rom_spiflash_unlock(void);
+extern void Cache_Invalidate_Addr(uint32_t addr, uint32_t size);
+*/
+import "C"
+
+// compile-time check for ensuring we fulfill BlockDevice interface
+var _ BlockDevice = flashBlockDevice{}
+
+var Flash flashBlockDevice
+
+type flashBlockDevice struct {
+}
+
+// ReadAt reads the given number of bytes from the block device.
+func (f flashBlockDevice) ReadAt(p []byte, off int64) (n int, err error) {
+	if readAddress(off)+uintptr(len(p)) > FlashDataEnd() {
+		return 0, errFlashCannotReadPastEOF
+	}
+
+	data := unsafe.Slice((*byte)(unsafe.Add(unsafe.Pointer(FlashDataStart()), off)), len(p))
+	copy(p, data)
+
+	return len(p), nil
+}
+
+// WriteAt writes the given number of bytes to the block device.
+// Only word (32 bits) length data can be programmed.
+// If the length of p is not long enough it will be padded with 0xFF bytes.
+// This method assumes that the destination is already erased.
+func (f flashBlockDevice) WriteAt(p []byte, off int64) (n int, err error) {
+	return f.writeAt(p, off)
+}
+
+// Size returns the number of bytes in this block device.
+func (f flashBlockDevice) Size() int64 {
+	return int64(FlashDataEnd() - FlashDataStart())
+}
+
+const writeBlockSize = 4
+
+// WriteBlockSize returns the block size in which data can be written to
+// memory. It can be used by a client to optimize writes, non-aligned writes
+// should always work correctly.
+func (f flashBlockDevice) WriteBlockSize() int64 {
+	return writeBlockSize
+}
+
+const eraseBlockSizeValue = 1 << 12
+
+func eraseBlockSize() int64 {
+	return eraseBlockSizeValue
+}
+
+// EraseBlockSize returns the smallest erasable area on this particular chip
+// in bytes. This is used for the block size in EraseBlocks.
+func (f flashBlockDevice) EraseBlockSize() int64 {
+	return eraseBlockSize()
+}
+
+// EraseBlocks erases the given number of blocks. An implementation may
+// transparently coalesce ranges of blocks into larger bundles if the chip
+// supports this. The start and len parameters are in block numbers, use
+// EraseBlockSize to map addresses to blocks.
+func (f flashBlockDevice) EraseBlocks(start, length int64) error {
+	return f.eraseBlocks(start, length)
+}
+
+// return the correct address to be used for reads
+func readAddress(off int64) uintptr {
+	return FlashDataStart() + uintptr(off)
+}
+
+const flashDROMStart = 0x3C000000
+
+// return the correct physical address to be used for write/erase
+func writeAddress(off int64) uint32 {
+	// DROM maps 1:1 with flash physical offset, starting at 0x3C000000.
+	return uint32(readAddress(off) - flashDROMStart)
+}
+
+func (f flashBlockDevice) writeAt(p []byte, off int64) (n int, err error) {
+	if readAddress(off)+uintptr(len(p)) > FlashDataEnd() {
+		return 0, errFlashCannotWritePastEOF
+	}
+
+	address := writeAddress(off)
+	padded := flashPad(p, int(f.WriteBlockSize()))
+
+	state := interrupt.Disable()
+	defer interrupt.Restore(state)
+
+	C.esp_rom_spiflash_unlock()
+	res := C.esp_rom_spiflash_write(C.uint32_t(address), (*C.uint32_t)(unsafe.Pointer(&padded[0])), C.uint32_t(len(padded)))
+	C.Cache_Invalidate_Addr(C.uint32_t(readAddress(off)), C.uint32_t(len(padded)))
+	if res != 0 {
+		return 0, errFlashCannotWriteData
+	}
+
+	return len(padded), nil
+}
+
+func (f flashBlockDevice) eraseBlocks(start, length int64) error {
+	address := writeAddress(start * f.EraseBlockSize())
+	if uintptr(unsafe.Add(unsafe.Pointer(uintptr(address)+flashDROMStart), length*f.EraseBlockSize())) > FlashDataEnd() {
+		return errFlashCannotErasePastEOF
+	}
+
+	state := interrupt.Disable()
+	defer interrupt.Restore(state)
+
+	C.esp_rom_spiflash_unlock()
+	sector := address / uint32(f.EraseBlockSize())
+
+	for i := int64(0); i < length; i++ {
+		res := C.esp_rom_spiflash_erase_sector(C.uint32_t(sector + uint32(i)))
+		C.Cache_Invalidate_Addr(C.uint32_t(readAddress((start+i)*f.EraseBlockSize())), C.uint32_t(f.EraseBlockSize()))
+		if res != 0 {
+			return errFlashCannotErasePage
+		}
+	}
+
+	return nil
+}

src/machine/machine_esp32c3_i2c.go

@@ -4,350 +4,18 @@ package machine
 
 import (
 	"device/esp"
-	"runtime/volatile"
-	"unsafe"
+)
+
+const (
+	I2CEXT0_SCL_OUT_IDX = 53
+	I2CEXT0_SDA_OUT_IDX = 54
 )
 
 var (
-	I2C0 = &I2C{}
+	I2C0 = &I2C{
+		Bus:     esp.I2C0,
+		funcSCL: I2CEXT0_SCL_OUT_IDX,
+		funcSDA: I2CEXT0_SDA_OUT_IDX,
+		useExt1: false,
+	}
 )
-
-type I2C struct{}
-
-// I2CConfig is used to store config info for I2C.
-type I2CConfig struct {
-	Frequency uint32 // in Hz
-	SCL       Pin
-	SDA       Pin
-}
-
-const (
-	clkXTAL               = 0
-	clkFOSC               = 1
-	clkXTALFrequency      = uint32(40e6)
-	clkFOSCFrequency      = uint32(17.5e6)
-	i2cClkSourceFrequency = clkXTALFrequency
-	i2cClkSource          = clkXTAL
-)
-
-func (i2c *I2C) Configure(config I2CConfig) error {
-	if config.Frequency == 0 {
-		config.Frequency = 400 * KHz
-	}
-	if config.SCL == 0 {
-		config.SCL = SCL_PIN
-	}
-	if config.SDA == 0 {
-		config.SDA = SDA_PIN
-	}
-
-	i2c.initClock(config)
-	i2c.initNoiseFilter()
-	i2c.initPins(config)
-	i2c.initFrequency(config)
-	i2c.startMaster()
-	return nil
-}
-
-//go:inline
-func (i2c *I2C) initClock(config I2CConfig) {
-	// reset I2C clock
-	esp.SYSTEM.SetPERIP_RST_EN0_I2C_EXT0_RST(1)
-	esp.SYSTEM.SetPERIP_CLK_EN0_I2C_EXT0_CLK_EN(1)
-	esp.SYSTEM.SetPERIP_RST_EN0_I2C_EXT0_RST(0)
-	// disable interrupts
-	esp.I2C0.INT_ENA.ClearBits(0x3fff)
-	esp.I2C0.INT_CLR.ClearBits(0x3fff)
-
-	esp.I2C0.SetCLK_CONF_SCLK_SEL(i2cClkSource)
-	esp.I2C0.SetCLK_CONF_SCLK_ACTIVE(1)
-	esp.I2C0.SetCLK_CONF_SCLK_DIV_NUM(i2cClkSourceFrequency / (config.Frequency * 1024))
-	esp.I2C0.SetCTR_CLK_EN(1)
-}
-
-//go:inline
-func (i2c *I2C) initNoiseFilter() {
-	esp.I2C0.FILTER_CFG.Set(0x377)
-}
-
-//go:inline
-func (i2c *I2C) initPins(config I2CConfig) {
-	var muxConfig uint32
-	const function = 1 // function 1 is just GPIO
-
-	// SDA
-	muxConfig = function << esp.IO_MUX_GPIO_MCU_SEL_Pos
-	// Make this pin an input pin (always).
-	muxConfig |= esp.IO_MUX_GPIO_FUN_IE
-	// Set drive strength: 0 is lowest, 3 is highest.
-	muxConfig |= 1 << esp.IO_MUX_GPIO_FUN_DRV_Pos
-	config.SDA.mux().Set(muxConfig)
-	config.SDA.outFunc().Set(54)
-	inFunc(54).Set(uint32(esp.GPIO_FUNC_IN_SEL_CFG_SEL | config.SDA))
-	config.SDA.Set(true)
-	// Configure the pad with the given IO mux configuration.
-	config.SDA.pinReg().SetBits(esp.GPIO_PIN_PAD_DRIVER)
-
-	esp.GPIO.ENABLE.SetBits(1 << int(config.SDA))
-	esp.I2C0.SetCTR_SDA_FORCE_OUT(1)
-
-	// SCL
-	muxConfig = function << esp.IO_MUX_GPIO_MCU_SEL_Pos
-	// Make this pin an input pin (always).
-	muxConfig |= esp.IO_MUX_GPIO_FUN_IE
-	// Set drive strength: 0 is lowest, 3 is highest.
-	muxConfig |= 1 << esp.IO_MUX_GPIO_FUN_DRV_Pos
-	config.SCL.mux().Set(muxConfig)
-	config.SCL.outFunc().Set(53)
-	inFunc(53).Set(uint32(config.SCL))
-	config.SCL.Set(true)
-	// Configure the pad with the given IO mux configuration.
-	config.SCL.pinReg().SetBits(esp.GPIO_PIN_PAD_DRIVER)
-
-	esp.GPIO.ENABLE.SetBits(1 << int(config.SCL))
-	esp.I2C0.SetCTR_SCL_FORCE_OUT(1)
-}
-
-//go:inline
-func (i2c *I2C) initFrequency(config I2CConfig) {
-
-	clkmDiv := i2cClkSourceFrequency/(config.Frequency*1024) + 1
-	sclkFreq := i2cClkSourceFrequency / clkmDiv
-	halfCycle := sclkFreq / config.Frequency / 2
-	//SCL
-	sclLow := halfCycle
-	sclWaitHigh := uint32(0)
-	if config.Frequency > 50000 {
-		sclWaitHigh = halfCycle / 8 // compensate the time when freq > 50K
-	}
-	sclHigh := halfCycle - sclWaitHigh
-	// SDA
-	sdaHold := halfCycle / 4
-	sda_sample := halfCycle / 2
-	setup := halfCycle
-	hold := halfCycle
-
-	esp.I2C0.SetSCL_LOW_PERIOD(sclLow - 1)
-	esp.I2C0.SetSCL_HIGH_PERIOD(sclHigh)
-	esp.I2C0.SetSCL_HIGH_PERIOD_SCL_WAIT_HIGH_PERIOD(25)
-	esp.I2C0.SetSCL_RSTART_SETUP_TIME(setup)
-	esp.I2C0.SetSCL_STOP_SETUP_TIME(setup)
-	esp.I2C0.SetSCL_START_HOLD_TIME(hold - 1)
-	esp.I2C0.SetSCL_STOP_HOLD_TIME(hold - 1)
-	esp.I2C0.SetSDA_SAMPLE_TIME(sda_sample)
-	esp.I2C0.SetSDA_HOLD_TIME(sdaHold)
-}
-
-//go:inline
-func (i2c *I2C) startMaster() {
-	// FIFO mode for data
-	esp.I2C0.SetFIFO_CONF_NONFIFO_EN(0)
-	// Reset TX & RX buffers
-	esp.I2C0.SetFIFO_CONF_RX_FIFO_RST(1)
-	esp.I2C0.SetFIFO_CONF_RX_FIFO_RST(0)
-	esp.I2C0.SetFIFO_CONF_TX_FIFO_RST(1)
-	esp.I2C0.SetFIFO_CONF_TX_FIFO_RST(0)
-	// set timeout value
-	esp.I2C0.TO.Set(0x10)
-	// enable master mode
-	esp.I2C0.CTR.Set(0x113)
-	esp.I2C0.SetCTR_CONF_UPGATE(1)
-	resetMaster()
-}
-
-//go:inline
-func resetMaster() {
-	// reset FSM
-	esp.I2C0.SetCTR_FSM_RST(1)
-	// clear the bus
-	esp.I2C0.SetSCL_SP_CONF_SCL_RST_SLV_NUM(9)
-	esp.I2C0.SetSCL_SP_CONF_SCL_RST_SLV_EN(1)
-	esp.I2C0.SetSCL_STRETCH_CONF_SLAVE_SCL_STRETCH_EN(1)
-	esp.I2C0.SetCTR_CONF_UPGATE(1)
-	esp.I2C0.FILTER_CFG.Set(0x377)
-	// wait for SCL_RST_SLV_EN
-	for esp.I2C0.GetSCL_SP_CONF_SCL_RST_SLV_EN() != 0 {
-	}
-	esp.I2C0.SetSCL_SP_CONF_SCL_RST_SLV_NUM(0)
-}
-
-type i2cCommandType = uint32
-type i2cAck = uint32
-
-const (
-	i2cCMD_RSTART   i2cCommandType = 6 << 11
-	i2cCMD_WRITE    i2cCommandType = 1<<11 | 1<<8 // WRITE + ack_check_en
-	i2cCMD_READ     i2cCommandType = 3<<11 | 1<<8 // READ + ack_check_en
-	i2cCMD_READLAST i2cCommandType = 3<<11 | 5<<8 // READ + ack_check_en + NACK
-	i2cCMD_STOP     i2cCommandType = 2 << 11
-	i2cCMD_END      i2cCommandType = 4 << 11
-)
-
-type i2cCommand struct {
-	cmd  i2cCommandType
-	data []byte
-	head int
-}
-
-//go:linkname nanotime runtime.nanotime
-func nanotime() int64
-
-func (i2c *I2C) transmit(addr uint16, cmd []i2cCommand, timeoutMS int) error {
-	const intMask = esp.I2C_INT_STATUS_END_DETECT_INT_ST_Msk | esp.I2C_INT_STATUS_TRANS_COMPLETE_INT_ST_Msk | esp.I2C_INT_STATUS_TIME_OUT_INT_ST_Msk | esp.I2C_INT_STATUS_NACK_INT_ST_Msk
-	esp.I2C0.INT_CLR.SetBits(intMask)
-	esp.I2C0.INT_ENA.SetBits(intMask)
-	esp.I2C0.SetCTR_CONF_UPGATE(1)
-
-	defer func() {
-		esp.I2C0.INT_CLR.SetBits(intMask)
-		esp.I2C0.INT_ENA.ClearBits(intMask)
-	}()
-
-	timeoutNS := int64(timeoutMS) * 1000000
-	needAddress := true
-	needRestart := false
-	readLast := false
-	var readTo []byte
-	for cmdIdx, reg := 0, &esp.I2C0.COMD0; cmdIdx < len(cmd); {
-		c := &cmd[cmdIdx]
-
-		switch c.cmd {
-		case i2cCMD_RSTART:
-			reg.Set(i2cCMD_RSTART)
-			reg = nextAddress(reg)
-			cmdIdx++
-
-		case i2cCMD_WRITE:
-			count := 32
-			if needAddress {
-				needAddress = false
-				esp.I2C0.SetDATA_FIFO_RDATA((uint32(addr) & 0x7f) << 1)
-				count--
-				esp.I2C0.SLAVE_ADDR.Set(uint32(addr))
-				esp.I2C0.SetCTR_CONF_UPGATE(1)
-			}
-			for ; count > 0 && c.head < len(c.data); count, c.head = count-1, c.head+1 {
-				esp.I2C0.SetDATA_FIFO_RDATA(uint32(c.data[c.head]))
-			}
-			reg.Set(i2cCMD_WRITE | uint32(32-count))
-			reg = nextAddress(reg)
-
-			if c.head < len(c.data) {
-				reg.Set(i2cCMD_END)
-				reg = nil
-			} else {
-				cmdIdx++
-			}
-			needRestart = true
-
-		case i2cCMD_READ:
-			if needAddress {
-				needAddress = false
-				esp.I2C0.SetDATA_FIFO_RDATA((uint32(addr)&0x7f)<<1 | 1)
-				esp.I2C0.SLAVE_ADDR.Set(uint32(addr))
-				reg.Set(i2cCMD_WRITE | 1)
-				reg = nextAddress(reg)
-			}
-			if needRestart {
-				// We need to send RESTART again after i2cCMD_WRITE.
-				reg.Set(i2cCMD_RSTART)
-
-				reg = nextAddress(reg)
-				reg.Set(i2cCMD_WRITE | 1)
-
-				reg = nextAddress(reg)
-				esp.I2C0.SetDATA_FIFO_RDATA((uint32(addr)&0x7f)<<1 | 1)
-				needRestart = false
-			}
-			count := 32
-			bytes := len(c.data) - c.head
-			// Only last byte in sequence must be sent with ACK set to 1 to indicate end of data.
-			split := bytes <= count
-			if split {
-				bytes--
-			}
-			if bytes > 32 {
-				bytes = 32
-			}
-			reg.Set(i2cCMD_READ | uint32(bytes))
-			reg = nextAddress(reg)
-
-			if split {
-				readLast = true
-				reg.Set(i2cCMD_READLAST | 1)
-				reg = nextAddress(reg)
-				readTo = c.data[c.head : c.head+bytes+1] // read bytes + 1 last byte
-				cmdIdx++
-			} else {
-				reg.Set(i2cCMD_END)
-				readTo = c.data[c.head : c.head+bytes]
-				reg = nil
-			}
-
-		case i2cCMD_STOP:
-			reg.Set(i2cCMD_STOP)
-			reg = nil
-			cmdIdx++
-		}
-		if reg == nil {
-			// transmit now
-			esp.I2C0.SetCTR_CONF_UPGATE(1)
-			esp.I2C0.SetCTR_TRANS_START(1)
-			end := nanotime() + timeoutNS
-			var mask uint32
-			for mask = esp.I2C0.INT_STATUS.Get(); mask&intMask == 0; mask = esp.I2C0.INT_STATUS.Get() {
-				if nanotime() > end {
-					if readTo != nil {
-						return errI2CReadTimeout
-					}
-					return errI2CWriteTimeout
-				}
-			}
-			switch {
-			case mask&esp.I2C_INT_STATUS_NACK_INT_ST_Msk != 0 && !readLast:
-				return errI2CAckExpected
-			case mask&esp.I2C_INT_STATUS_TIME_OUT_INT_ST_Msk != 0:
-				if readTo != nil {
-					return errI2CReadTimeout
-				}
-				return errI2CWriteTimeout
-			}
-			esp.I2C0.INT_CLR.SetBits(intMask)
-			for i := 0; i < len(readTo); i++ {
-				readTo[i] = byte(esp.I2C0.GetDATA_FIFO_RDATA() & 0xff)
-				c.head++
-			}
-			readTo = nil
-			reg = &esp.I2C0.COMD0
-		}
-	}
-	return nil
-}
-
-// Tx does a single I2C transaction at the specified address.
-// It clocks out the given address, writes the bytes in w, reads back len(r)
-// bytes and stores them in r, and generates a stop condition on the bus.
-func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) {
-	// timeout in microseconds.
-	const timeout = 40 // 40ms is a reasonable time for a real-time system.
-
-	cmd := make([]i2cCommand, 0, 8)
-	cmd = append(cmd, i2cCommand{cmd: i2cCMD_RSTART})
-	if len(w) > 0 {
-		cmd = append(cmd, i2cCommand{cmd: i2cCMD_WRITE, data: w})
-	}
-	if len(r) > 0 {
-		cmd = append(cmd, i2cCommand{cmd: i2cCMD_READ, data: r})
-	}
-	cmd = append(cmd, i2cCommand{cmd: i2cCMD_STOP})
-
-	return i2c.transmit(addr, cmd, timeout)
-}
-
-func (i2c *I2C) SetBaudRate(br uint32) error {
-	return nil
-}
-
-func nextAddress(reg *volatile.Register32) *volatile.Register32 {
-	return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(reg), 4))
-}

src/machine/machine_esp32c3_pwm.go

@@ -0,0 +1,178 @@
+//go:build esp32c3
+
+package machine
+
+import "device/esp"
+
+// LEDC PWM for ESP32-C3: 4 timers (PWM0–PWM3), 6 channels per timer; each timer has its own frequency.
+// Range: frequency from a few Hz up to ~40 MHz (at 1-bit resolution); duty resolution 1–15 bits
+// (higher frequency gives lower resolution). Clock source: APB 80 MHz. Low-speed mode only.
+// See ESP-IDF LEDC driver, TRM LED PWM Controller.
+
+// GPIO matrix output signal indices for LEDC (soc/gpio_sig_map.h)
+const (
+	LEDC_LS_SIG_OUT0_IDX = 45
+)
+
+const ledcChannelsC3 = 6
+
+var (
+	PWM0 = &LEDCPWM{SigOutBase: LEDC_LS_SIG_OUT0_IDX, NumChannels: ledcChannelsC3, timerNum: 0}
+	PWM1 = &LEDCPWM{SigOutBase: LEDC_LS_SIG_OUT0_IDX, NumChannels: ledcChannelsC3, timerNum: 1}
+	PWM2 = &LEDCPWM{SigOutBase: LEDC_LS_SIG_OUT0_IDX, NumChannels: ledcChannelsC3, timerNum: 2}
+	PWM3 = &LEDCPWM{SigOutBase: LEDC_LS_SIG_OUT0_IDX, NumChannels: ledcChannelsC3, timerNum: 3}
+)
+
+// chanOp implements LEDC low-speed channel ops for ESP32-C3 (channels 0–5 only).
+func (pwm *LEDCPWM) chanOp(ch uint8, op ledcChanOp, duty uint32, inverting bool) {
+	invVal := uint32(0)
+	if inverting {
+		invVal = 1
+	}
+	switch ch {
+	case 0:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH0_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH0_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH0_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH0_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH0_DUTY_DUTY(0)
+			esp.LEDC.SetCH0_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH0_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH0_DUTY_DUTY(duty)
+			esp.LEDC.SetCH0_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH0_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH0_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH0_CONF0_IDLE_LV(invVal)
+		}
+	case 1:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH1_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH1_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH1_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH1_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH1_DUTY_DUTY(0)
+			esp.LEDC.SetCH1_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH1_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH1_DUTY_DUTY(duty)
+			esp.LEDC.SetCH1_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH1_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH1_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH1_CONF0_IDLE_LV(invVal)
+		}
+	case 2:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH2_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH2_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH2_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH2_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH2_DUTY_DUTY(0)
+			esp.LEDC.SetCH2_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH2_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH2_DUTY_DUTY(duty)
+			esp.LEDC.SetCH2_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH2_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH2_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH2_CONF0_IDLE_LV(invVal)
+		}
+	case 3:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH3_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH3_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH3_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH3_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH3_DUTY_DUTY(0)
+			esp.LEDC.SetCH3_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH3_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH3_DUTY_DUTY(duty)
+			esp.LEDC.SetCH3_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH3_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH3_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH3_CONF0_IDLE_LV(invVal)
+		}
+	case 4:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH4_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH4_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH4_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH4_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH4_DUTY_DUTY(0)
+			esp.LEDC.SetCH4_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH4_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH4_DUTY_DUTY(duty)
+			esp.LEDC.SetCH4_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH4_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH4_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH4_CONF0_IDLE_LV(invVal)
+		}
+	case 5:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH5_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH5_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH5_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH5_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH5_DUTY_DUTY(0)
+			esp.LEDC.SetCH5_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH5_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH5_DUTY_DUTY(duty)
+			esp.LEDC.SetCH5_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH5_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH5_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH5_CONF0_IDLE_LV(invVal)
+		}
+	}
+}

src/machine/machine_esp32c3_spi.go

@@ -16,11 +16,6 @@ import (
 )
 
 const (
-	SPI_MODE0 = uint8(0)
-	SPI_MODE1 = uint8(1)
-	SPI_MODE2 = uint8(2)
-	SPI_MODE3 = uint8(3)
-
 	FSPICLK_IN_IDX  = uint32(63)
 	FSPICLK_OUT_IDX = uint32(63)
 	FSPIQ_IN_IDX    = uint32(64)
@@ -53,66 +48,9 @@ type SPI struct {
 var (
 	// SPI0 and SPI1 are reserved for use by the caching system etc.
 	SPI2 = &SPI{esp.SPI2}
+	SPI0 = SPI2
 )
 
-// SPIConfig is used to store config info for SPI.
-type SPIConfig struct {
-	Frequency uint32
-	SCK       Pin   // Serial Clock
-	SDO       Pin   // Serial Data Out (MOSI)
-	SDI       Pin   // Serial Data In  (MISO)
-	CS        Pin   // Chip Select (optional)
-	LSBFirst  bool  // MSB is default
-	Mode      uint8 // SPI_MODE0 is default
-}
-
-// Compute the SPI bus frequency from the CPU frequency.
-func freqToClockDiv(hz uint32) uint32 {
-	fcpu := CPUFrequency()
-	if hz >= fcpu { // maximum frequency
-		return 1 << 31
-	}
-	if hz < (fcpu / (16 * 64)) { // minimum frequency
-		return 15<<18 | 63<<12 | 31<<6 | 63 // pre=15, n=63
-	}
-
-	// iterate looking for an exact match
-	// or iterate all 16 prescaler options
-	// looking for the smallest error
-	var bestPre, bestN, bestErr uint32
-	bestN = 1
-	bestErr = 0xffffffff
-	q := uint32(float32(pplClockFreq)/float32(hz) + float32(0.5))
-	for p := uint32(0); p < 16; p++ {
-		n := q/(p+1) - 1
-		if n < 1 { // prescaler became too large, stop enum
-			break
-		}
-		if n > 63 { // prescaler too small, skip to next
-			continue
-		}
-
-		freq := fcpu / ((p + 1) * (n + 1))
-		if freq == hz { // exact match
-			return p<<18 | n<<12 | (n/2)<<6 | n
-		}
-
-		var err uint32
-		if freq < hz {
-			err = hz - freq
-		} else {
-			err = freq - hz
-		}
-		if err < bestErr {
-			bestErr = err
-			bestPre = p
-			bestN = n
-		}
-	}
-
-	return bestPre<<18 | bestN<<12 | (bestN/2)<<6 | bestN
-}
-
 // Configure and make the SPI peripheral ready to use.
 func (spi *SPI) Configure(config SPIConfig) error {
 	// right now this is only setup to work for the esp32c3 spi2 bus
@@ -171,16 +109,16 @@ func (spi *SPI) Configure(config SPIConfig) error {
 
 	// set spi2 data mode
 	switch config.Mode {
-	case SPI_MODE0:
+	case Mode0:
 		spi.Bus.SetMISC_CK_IDLE_EDGE(0)
 		spi.Bus.SetUSER_CK_OUT_EDGE(0)
-	case SPI_MODE1:
+	case Mode1:
 		spi.Bus.SetMISC_CK_IDLE_EDGE(0)
 		spi.Bus.SetUSER_CK_OUT_EDGE(1)
-	case SPI_MODE2:
+	case Mode2:
 		spi.Bus.SetMISC_CK_IDLE_EDGE(1)
 		spi.Bus.SetUSER_CK_OUT_EDGE(1)
-	case SPI_MODE3:
+	case Mode3:
 		spi.Bus.SetMISC_CK_IDLE_EDGE(1)
 		spi.Bus.SetUSER_CK_OUT_EDGE(0)
 	default:
@@ -199,6 +137,12 @@ func (spi *SPI) Configure(config SPIConfig) error {
 	// configure SPI bus clock
 	spi.Bus.CLOCK.Set(freqToClockDiv(config.Frequency))
 
+	// Default CS to NoPin so that an unset CS field (zero value = GPIO0)
+	// does not accidentally configure GPIO0 as the chip select output.
+	if config.CS == 0 {
+		config.CS = NoPin
+	}
+
 	// configure esp32c3 gpio pin matrix
 	config.SDI.Configure(PinConfig{Mode: PinInput})
 	inFunc(FSPIQ_IN_IDX).Set(esp.GPIO_FUNC_IN_SEL_CFG_SEL | uint32(config.SDI))
@@ -253,36 +197,7 @@ func (spi *SPI) Tx(w, r []byte) error {
 
 		// Fill tx buffer.
 		transferWords := (*[16]volatile.Register32)(unsafe.Pointer(uintptr(unsafe.Pointer(&spi.Bus.W0))))
-		if len(w) >= 64 {
-			// We can fill the entire 64-byte transfer buffer with data.
-			// This loop is slightly faster than the loop below.
-			for i := 0; i < 16; i++ {
-				word := uint32(w[i*4]) | uint32(w[i*4+1])<<8 | uint32(w[i*4+2])<<16 | uint32(w[i*4+3])<<24
-				transferWords[i].Set(word)
-			}
-		} else {
-			// We can't fill the entire transfer buffer, so we need to be a bit
-			// more careful.
-			// Note that parts of the transfer buffer that aren't used still
-			// need to be set to zero, otherwise we might be transferring
-			// garbage from a previous transmission if w is smaller than r.
-			for i := 0; i < 16; i++ {
-				var word uint32
-				if i*4+3 < len(w) {
-					word |= uint32(w[i*4+3]) << 24
-				}
-				if i*4+2 < len(w) {
-					word |= uint32(w[i*4+2]) << 16
-				}
-				if i*4+1 < len(w) {
-					word |= uint32(w[i*4+1]) << 8
-				}
-				if i*4+0 < len(w) {
-					word |= uint32(w[i*4+0]) << 0
-				}
-				transferWords[i].Set(word)
-			}
-		}
+		spiTxFillBuffer(transferWords, w)
 
 		// Do the transfer.
 		spi.Bus.SetMS_DLEN_MS_DATA_BITLEN(uint32(chunkSize)*8 - 1)

src/machine/machine_esp32c3_usb.go

@@ -0,0 +1,285 @@
+//go:build esp32c3
+
+package machine
+
+import (
+	"device/esp"
+	"errors"
+	"machine/usb"
+	"machine/usb/descriptor"
+	"runtime/interrupt"
+)
+
+// USB Serial/JTAG Controller
+// See esp32-c3_technical_reference_manual_en.pdf pg. 736
+//
+// The ESP32-C3 has a built-in USB Serial/JTAG controller that provides a
+// CDC-ACM serial port. The USB protocol and enumeration are handled entirely
+// in hardware; software only reads/writes the EP1 FIFO.
+
+const cpuInterruptFromUSB = 10
+
+type USB_DEVICE struct {
+	Bus       *esp.USB_DEVICE_Type
+	Buffer    *RingBuffer
+	txPending bool // unflushed data in the EP1 TX FIFO
+	txStalled bool // set when flushAndWait fails (no host reading); cleared when FIFO becomes writable
+}
+
+var (
+	_USBCDC = &USB_DEVICE{
+		Bus:    esp.USB_DEVICE,
+		Buffer: NewRingBuffer(),
+	}
+
+	USBCDC Serialer = _USBCDC
+)
+
+var (
+	errUSBWrongSize            = errors.New("USB: invalid write size")
+	errUSBCouldNotWriteAllData = errors.New("USB: could not write all data")
+)
+
+type Serialer interface {
+	WriteByte(c byte) error
+	Write(data []byte) (n int, err error)
+	Configure(config UARTConfig) error
+	Buffered() int
+	ReadByte() (byte, error)
+	DTR() bool
+	RTS() bool
+}
+
+var usbConfigured bool
+
+// USBDevice provides a stub USB device for the ESP32-C3.  The hardware
+// only supports a fixed-function CDC-ACM serial port, so the programmable
+// USB device features are no-ops.
+type USBDevice struct {
+	initcomplete         bool
+	InitEndpointComplete bool
+}
+
+var USBDev = &USBDevice{}
+
+func (dev *USBDevice) SetStallEPIn(ep uint32)    {}
+func (dev *USBDevice) SetStallEPOut(ep uint32)   {}
+func (dev *USBDevice) ClearStallEPIn(ep uint32)  {}
+func (dev *USBDevice) ClearStallEPOut(ep uint32) {}
+
+// initUSB is intentionally empty — the interp phase evaluates init()
+// functions at compile time and cannot access hardware registers.
+// Actual hardware setup is deferred to the first Configure() call.
+func initUSB() {}
+
+// Configure initialises the USB Serial/JTAG controller clock, pads, and
+// interrupt so that received data is buffered automatically.
+func (usbdev *USB_DEVICE) Configure(config UARTConfig) error {
+	if usbConfigured {
+		return nil
+	}
+	usbConfigured = true
+
+	// Enable the USB_DEVICE peripheral clock.
+	// Do NOT reset the peripheral — the ROM bootloader has already
+	// configured the USB Serial/JTAG controller and the host may
+	// already be connected. Resetting would drop the USB link.
+	esp.SYSTEM.SetPERIP_CLK_EN0_USB_DEVICE_CLK_EN(1)
+	esp.SYSTEM.SetPERIP_RST_EN0_USB_DEVICE_RST(0)
+
+	// Ensure internal PHY is selected and USB pads are enabled.
+	usbdev.Bus.SetCONF0_PHY_SEL(0)
+	usbdev.Bus.SetCONF0_USB_PAD_ENABLE(1)
+	usbdev.Bus.SetCONF0_DP_PULLUP(1)
+
+	// Clear any pending interrupts.
+	usbdev.Bus.INT_CLR.Set(0xFFFFFFFF)
+
+	// Enable the RX-packet-received interrupt.
+	usbdev.Bus.SetINT_ENA_SERIAL_OUT_RECV_PKT_INT_ENA(1)
+
+	// Map the USB peripheral interrupt to CPU interrupt cpuInterruptFromUSB.
+	esp.INTERRUPT_CORE0.SetUSB_INTR_MAP(cpuInterruptFromUSB)
+
+	_ = interrupt.New(cpuInterruptFromUSB, func(interrupt.Interrupt) {
+		_USBCDC.handleInterrupt()
+	}).Enable()
+
+	return nil
+}
+
+// ensureConfigured triggers lazy initialization on first use.
+func (usbdev *USB_DEVICE) ensureConfigured() {
+	if !usbConfigured {
+		usbdev.Configure(UARTConfig{})
+	}
+}
+
+// handleInterrupt drains the hardware RX FIFO into the software ring buffer.
+func (usbdev *USB_DEVICE) handleInterrupt() {
+	// Read INT_ST while INT_ENA is still set (INT_ST = INT_RAW & INT_ENA).
+	intStatus := usbdev.Bus.INT_ST.Get()
+
+	// Disable the RX interrupt to prevent re-triggering while we drain.
+	usbdev.Bus.SetINT_ENA_SERIAL_OUT_RECV_PKT_INT_ENA(0)
+
+	if intStatus&esp.USB_DEVICE_INT_ST_SERIAL_OUT_RECV_PKT_INT_ST != 0 {
+		// Drain all available bytes from the EP1 OUT FIFO.
+		// Use EP1.Get() directly — the generated GetEP1_RDWR_BYTE is
+		// functionally identical, but a direct load makes the FIFO-pop
+		// intent explicit.
+		for usbdev.Bus.GetEP1_CONF_SERIAL_OUT_EP_DATA_AVAIL() != 0 {
+			b := byte(usbdev.Bus.EP1.Get())
+			usbdev.Buffer.Put(b)
+		}
+		// Clear the interrupt.
+		usbdev.Bus.SetINT_CLR_SERIAL_OUT_RECV_PKT_INT_CLR(1)
+	}
+
+	// Re-enable the RX interrupt.
+	usbdev.Bus.SetINT_ENA_SERIAL_OUT_RECV_PKT_INT_ENA(1)
+}
+
+func (usbdev *USB_DEVICE) WriteByte(c byte) error {
+	usbdev.ensureConfigured()
+	if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
+		// FIFO locked by a pending USB transfer.
+		if usbdev.txStalled {
+			// Previously failed — skip the expensive spin and drop
+			// the byte. When a host reconnects SERIAL_IN_EP_DATA_FREE
+			// goes back to 1, clearing the stall on the next call.
+			return errUSBCouldNotWriteAllData
+		}
+		// First time the FIFO is full: wait briefly for the host to
+		// read the previous packet.
+		if !usbdev.flushAndWait() {
+			usbdev.txStalled = true
+			return errUSBCouldNotWriteAllData
+		}
+	}
+	usbdev.txStalled = false
+
+	// Use EP1.Set() (direct store) instead of SetEP1_RDWR_BYTE which
+	// does a read-modify-write — the read side-effect pops a byte from
+	// the RX FIFO.
+	usbdev.Bus.EP1.Set(uint32(c))
+
+	// Only signal WR_DONE on newline to batch bytes into a single USB
+	// packet. The FIFO-full path above also flushes when the 64-byte
+	// FIFO fills up.
+	if c == '\n' {
+		usbdev.flush()
+		usbdev.txPending = false
+	} else {
+		usbdev.txPending = true
+	}
+
+	return nil
+}
+
+func (usbdev *USB_DEVICE) Write(data []byte) (n int, err error) {
+	usbdev.ensureConfigured()
+	if len(data) == 0 {
+		return 0, nil
+	}
+
+	for i, c := range data {
+		if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
+			if usbdev.txStalled {
+				return i, errUSBCouldNotWriteAllData
+			}
+			if !usbdev.flushAndWait() {
+				usbdev.txStalled = true
+				return i, errUSBCouldNotWriteAllData
+			}
+		}
+		usbdev.txStalled = false
+		usbdev.Bus.EP1.Set(uint32(c))
+	}
+
+	usbdev.flush()
+	usbdev.txPending = false
+	return len(data), nil
+}
+
+// Buffered returns the number of bytes waiting in the receive ring buffer.
+func (usbdev *USB_DEVICE) Buffered() int {
+	usbdev.ensureConfigured()
+	// Flush any pending TX data so callers like echo loops don't
+	// need to explicitly flush after WriteByte.
+	if usbdev.txPending {
+		usbdev.flush()
+		usbdev.txPending = false
+	}
+	return int(usbdev.Buffer.Used())
+}
+
+// ReadByte returns a byte from the receive ring buffer.
+func (usbdev *USB_DEVICE) ReadByte() (byte, error) {
+	b, ok := usbdev.Buffer.Get()
+	if !ok {
+		return 0, nil
+	}
+	return b, nil
+}
+
+func (usbdev *USB_DEVICE) DTR() bool {
+	return false
+}
+
+func (usbdev *USB_DEVICE) RTS() bool {
+	return false
+}
+
+// flush signals WR_DONE to tell the hardware to send the data that has
+// been written to the EP1 FIFO. Returns immediately without waiting.
+func (usbdev *USB_DEVICE) flush() {
+	usbdev.Bus.SetEP1_CONF_WR_DONE(1)
+}
+
+// FlushSerial flushes any pending USB serial TX data. Called from the
+// runtime (e.g. before sleeping) to ensure data from print() without
+// a trailing newline gets sent promptly.
+func FlushSerial() {
+	if _USBCDC.txPending {
+		_USBCDC.flush()
+		_USBCDC.txPending = false
+	}
+}
+
+// flushAndWait signals WR_DONE and waits for the EP1 FIFO to become
+// writable again. The timeout covers a few USB frames so that data gets
+// through when a host is connected. Returns false if the FIFO is still
+// locked after the timeout (no host reading).
+func (usbdev *USB_DEVICE) flushAndWait() bool {
+	usbdev.Bus.SetEP1_CONF_WR_DONE(1)
+	for i := 0; i < 50000; i++ {
+		if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() != 0 {
+			return true
+		}
+	}
+	return false
+}
+
+// The ESP32-C3 USB Serial/JTAG controller is fixed-function hardware.
+// It only provides a CDC-ACM serial port; the USB protocol and endpoint
+// configuration are handled entirely in silicon.  The functions below
+// are no-op stubs so that higher-level USB packages (HID, MIDI, …)
+// compile, but they cannot add real endpoints on this hardware.
+
+// ConfigureUSBEndpoint is a no-op on ESP32-C3 — the hardware does not
+// support programmable USB endpoints.
+func ConfigureUSBEndpoint(desc descriptor.Descriptor, epSettings []usb.EndpointConfig, setup []usb.SetupConfig) {
+}
+
+// SendZlp is a no-op on ESP32-C3 — the hardware handles control
+// transfers internally.
+func SendZlp() {
+}
+
+// SendUSBInPacket is a no-op on ESP32-C3 — the hardware does not
+// support arbitrary IN endpoints.  Returns false to indicate the
+// packet was not sent.
+func SendUSBInPacket(ep uint32, data []byte) bool {
+	return false
+}

src/machine/machine_esp32s3.go

@@ -5,7 +5,9 @@ package machine
 import (
 	"device/esp"
 	"errors"
+	"runtime/interrupt"
 	"runtime/volatile"
+	"sync"
 	"unsafe"
 )
 
@@ -70,6 +72,7 @@ const (
 	PinInput
 	PinInputPullup
 	PinInputPulldown
+	PinAnalog
 )
 
 // Hardware pin numbers
@@ -121,6 +124,29 @@ const (
 	GPIO48 Pin = 48
 )
 
+const (
+	ADC0  Pin = GPIO1
+	ADC2  Pin = GPIO2
+	ADC3  Pin = GPIO3
+	ADC4  Pin = GPIO4
+	ADC5  Pin = GPIO5
+	ADC6  Pin = GPIO6
+	ADC7  Pin = GPIO7
+	ADC8  Pin = GPIO8
+	ADC9  Pin = GPIO9
+	ADC10 Pin = GPIO10
+	ADC11 Pin = GPIO11
+	ADC12 Pin = GPIO12
+	ADC13 Pin = GPIO13
+	ADC14 Pin = GPIO14
+	ADC15 Pin = GPIO15
+	ADC16 Pin = GPIO16
+	ADC17 Pin = GPIO17
+	ADC18 Pin = GPIO18
+	ADC19 Pin = GPIO19
+	ADC20 Pin = GPIO20
+)
+
 // Configure this pin with the given configuration.
 func (p Pin) Configure(config PinConfig) {
 	// Output function 256 is a special value reserved for use as a regular GPIO
@@ -146,8 +172,10 @@ func (p Pin) configure(config PinConfig, signal uint32) {
 	// MCU_SEL: Function 1 is always GPIO
 	ioConfig |= (1 << esp.IO_MUX_GPIO_MCU_SEL_Pos)
 
-	// FUN_IE: Make this pin an input pin (always set for GPIO operation)
-	ioConfig |= esp.IO_MUX_GPIO_FUN_IE
+	// FUN_IE: disable for PinAnalog (high-Z for ADC), enable for digital
+	if config.Mode != PinAnalog {
+		ioConfig |= esp.IO_MUX_GPIO_FUN_IE
+	}
 
 	// DRV: Set drive strength to 20 mA as a default. Pins 17 and 18 are special
 	var drive uint32
@@ -158,7 +186,7 @@ func (p Pin) configure(config PinConfig, signal uint32) {
 	}
 	ioConfig |= (drive << esp.IO_MUX_GPIO_FUN_DRV_Pos)
 
-	// WPU/WPD: Select pull mode.
+	// WPU/WPD: no pulls for PinAnalog
 	if config.Mode == PinInputPullup {
 		ioConfig |= esp.IO_MUX_GPIO_FUN_WPU
 	} else if config.Mode == PinInputPulldown {
@@ -181,14 +209,14 @@ func (p Pin) configure(config PinConfig, signal uint32) {
 		// output signal, or the special value 256 which indicates regular GPIO
 		// usage.
 		p.outFunc().Set(signal)
-	case PinInput, PinInputPullup, PinInputPulldown:
+	case PinInput, PinInputPullup, PinInputPulldown, PinAnalog:
 		// Clear the 'output enable' bit.
 		if p < 32 {
 			esp.GPIO.ENABLE_W1TC.Set(1 << p)
 		} else {
 			esp.GPIO.ENABLE1_W1TC.Set(1 << (p - 32))
 		}
-		if signal != 256 {
+		if signal != 256 && config.Mode != PinAnalog {
 			// Signal is a peripheral function (not a simple GPIO). Connect this
 			// signal to the pin.
 			// Note that outFunc and inFunc work in the opposite direction.
@@ -273,6 +301,105 @@ func (p Pin) Get() bool {
 	}
 }
 
+func (p Pin) pinReg() *volatile.Register32 {
+	return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(&esp.GPIO.PIN0), uintptr(p)*4))
+}
+
+const maxPin = 49
+
+// cpuInterruptFromPin selects an edge-triggered CPU interrupt line for GPIO.
+// CPU interrupt 10 is edge-triggered level-1 on the Xtensa LX7, which prevents
+// the ISR from re-entering continuously when other peripherals (e.g. SPI via
+// the GPIO Matrix) keep GPIO.STATUS bits asserted.
+const cpuInterruptFromPin = 10
+
+type PinChange uint8
+
+// Pin change interrupt constants for SetInterrupt.
+const (
+	PinRising PinChange = iota + 1
+	PinFalling
+	PinToggle
+)
+
+// SetInterrupt sets an interrupt to be executed when a particular pin changes
+// state. The pin should already be configured as an input, including a pull up
+// or down if no external pull is provided.
+//
+// You can pass a nil func to unset the pin change interrupt. If you do so,
+// the change parameter is ignored and can be set to any value (such as 0).
+// If the pin is already configured with a callback, you must first unset
+// this pins interrupt before you can set a new callback.
+func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) (err error) {
+	if p >= maxPin {
+		return ErrInvalidInputPin
+	}
+
+	if callback == nil {
+		// Disable this pin interrupt
+		p.pinReg().ClearBits(esp.GPIO_PIN_INT_TYPE_Msk | esp.GPIO_PIN_INT_ENA_Msk)
+
+		if pinCallbacks[p] != nil {
+			pinCallbacks[p] = nil
+		}
+		return nil
+	}
+
+	if pinCallbacks[p] != nil {
+		// The pin was already configured.
+		// To properly re-configure a pin, unset it first and set a new
+		// configuration.
+		return ErrNoPinChangeChannel
+	}
+	pinCallbacks[p] = callback
+
+	onceSetupPinInterrupt.Do(func() {
+		err = setupPinInterrupt()
+	})
+	if err != nil {
+		return err
+	}
+
+	p.pinReg().Set(
+		(p.pinReg().Get() & ^uint32(esp.GPIO_PIN_INT_TYPE_Msk|esp.GPIO_PIN_INT_ENA_Msk)) |
+			uint32(change)<<esp.GPIO_PIN_INT_TYPE_Pos | uint32(1)<<esp.GPIO_PIN_INT_ENA_Pos)
+
+	return nil
+}
+
+var (
+	pinCallbacks          [maxPin]func(Pin)
+	onceSetupPinInterrupt sync.Once
+)
+
+func setupPinInterrupt() error {
+	esp.INTERRUPT_CORE0.SetGPIO_INTERRUPT_PRO_MAP(cpuInterruptFromPin)
+	return interrupt.New(cpuInterruptFromPin, func(interrupt.Interrupt) {
+		// Read and immediately clear interrupt status bits.
+		// Clearing before processing is critical for edge-triggered CPU
+		// interrupts: any new GPIO events that arrive during callback
+		// execution will set fresh STATUS bits, generating a new edge
+		// on the CPU interrupt line so they are not lost.
+		status := esp.GPIO.STATUS.Get()
+		status1 := esp.GPIO.STATUS1.Get()
+		esp.GPIO.STATUS_W1TC.Set(status)
+		esp.GPIO.STATUS1_W1TC.Set(status1)
+
+		// Check status for GPIO0-31
+		for i, mask := 0, uint32(1); i < 32; i, mask = i+1, mask<<1 {
+			if (status&mask) != 0 && pinCallbacks[i] != nil {
+				pinCallbacks[i](Pin(i))
+			}
+		}
+		// Check status for GPIO32-48
+		for i, mask := 32, uint32(1); i < maxPin; i, mask = i+1, mask<<1 {
+			if (status1&mask) != 0 && pinCallbacks[i] != nil {
+				pinCallbacks[i](Pin(i))
+			}
+		}
+	}).Enable()
+}
+
 var DefaultUART = UART0
 
 var (
@@ -308,3 +435,38 @@ func (uart *UART) writeByte(b byte) error {
 }
 
 func (uart *UART) flush() {}
+
+// GetRNG returns 32-bit random numbers using the ESP32-S3 true random number generator,
+// Random numbers are generated based on the thermal noise in the system and the
+// asynchronous clock mismatch.
+// For maximum entropy also make sure that the SAR_ADC is enabled.
+// See esp32-s3_technical_reference_manual_en.pdf p.920
+func GetRNG() (ret uint32, err error) {
+	// ensure ADC clock is initialized
+	initADCClock()
+
+	// ensure fast RTC clock is enabled
+	if esp.RTC_CNTL.GetCLK_CONF_DIG_CLK8M_EN() == 0 {
+		esp.RTC_CNTL.SetCLK_CONF_DIG_CLK8M_EN(1)
+	}
+
+	return esp.RNG.DATA.Get(), nil
+}
+
+func initADCClock() {
+	if esp.APB_SARADC.GetCLKM_CONF_CLK_EN() == 1 {
+		return
+	}
+
+	// only support ADC_CTRL_CLK set to 1
+	esp.APB_SARADC.SetCLKM_CONF_CLK_SEL(1)
+
+	esp.APB_SARADC.SetCTRL_SARADC_SAR_CLK_GATED(1)
+
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_NUM(15)
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_B(1)
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_A(0)
+
+	esp.APB_SARADC.SetCTRL_SARADC_SAR_CLK_DIV(1)
+	esp.APB_SARADC.SetCLKM_CONF_CLK_EN(1)
+}

src/machine/machine_esp32s3_adc.go

@@ -0,0 +1,432 @@
+//go:build esp32s3
+
+// ESP32-S3: 2 SAR ADCs, 12-bit hardware; Get() returns 0..65520 (scaled from 12-bit).
+// Pin mapping: ADC1 = GPIO 1..10 (channel = GPIO-1); ADC2 = GPIO 11..20 (channel = GPIO-11).
+// Get() returns raw, uncalibrated ADC values; accurate 0–3.3V mapping should be done
+// either by a two-point calibration in user code or by using the eFuse-based
+// calibration logic (see IDF adc_cali / our ADCSelfCalibrate implementation).
+//
+// Registers used (TRM / IDF):
+//   SYSTEM:     PERIP_RST_EN0.APB_SARADC_RST, PERIP_CLK_EN0.APB_SARADC_CLK_EN
+//   RTC_CNTL:   ANA_CONF.SAR_I2C_PU, I2C_RESET_POR_FORCE_PU
+// ADC1 RTC path (oneshot, TRM/IDF):
+//   SENS.SAR_MEAS1_MUX.SAR1_DIG_FORCE = 0  → ADC1 under RTC (not digital/APB)
+//   SENS.SAR_MEAS1_CTRL2.MEAS1_START_FORCE = 1, SAR1_EN_PAD_FORCE = 1  → SW triggers and selects channel
+//   Per conversion: set attenuation (SAR_ATTEN1), channel (SAR1_EN_PAD), then MEAS1_START_SAR 0→1; wait MEAS1_DONE_SAR; read MEAS1_DATA_SAR.
+//   SENS.SAR_MEAS1_CTRL1: amp/ref (FORCE_XPD_AMP etc). SAR_MEAS1_CTRL2: MEAS1_DONE_SAR (done), MEAS1_START_SAR (start), MEAS1_DATA_SAR (12-bit result).
+//   APB_SARADC: FSM_WAIT, CLKM, etc. used for clock/shared logic; ADC2 uses ARB_CTRL.
+
+package machine
+
+import (
+	"device/esp"
+	"errors"
+	"runtime/volatile"
+	"unsafe"
+)
+
+// newRegI2C returns the regI2C configured for ESP32-S3: hostID=1, drefInit=4.
+func newRegI2C() regI2C { return regI2C{hostID: 1, drefInit: 4} }
+
+var adcDigiRefMv uint32
+
+func InitADC() {
+	// SYSTEM: reset and enable APB_SARADC clock so SAR registers are accessible.
+	esp.SYSTEM.SetPERIP_RST_EN0_APB_SARADC_RST(1)
+	esp.SYSTEM.SetPERIP_CLK_EN0_APB_SARADC_CLK_EN(1)
+	esp.SYSTEM.SetPERIP_RST_EN0_APB_SARADC_RST(0)
+
+	// SENS.SAR_PERI_CLK_GATE_CONF: enable SENS SAR peripheral clock (matches Arduino/IDF runtime state).
+	esp.SENS.SetSAR_PERI_CLK_GATE_CONF_SARADC_CLK_EN(1)
+
+	// RTC_CNTL.ANA_CONF: keep internal SAR I2C (regI2C analog bus) powered and out of reset.
+	esp.RTC_CNTL.SetANA_CONF_I2C_RESET_POR_FORCE_PD(0)
+	esp.RTC_CNTL.SetANA_CONF_SAR_I2C_PU(1)
+	esp.RTC_CNTL.SetANA_CONF_I2C_RESET_POR_FORCE_PU(1)
+
+	// SENS.SAR_POWER: power up SAR analog block and enable SAR internal clock.
+	esp.SENS.SetSAR_POWER_XPD_SAR_FORCE_XPD_SAR(3)
+	esp.SENS.SetSAR_POWER_XPD_SAR_SARCLK_EN(1)
+
+	// SENS.SAR_MEAS1_CTRL1: force ADC1 front-end amplifier and reference on in RTC oneshot mode.
+	esp.SENS.SetSAR_MEAS1_CTRL1_FORCE_XPD_AMP(3)
+	esp.SENS.SetSAR_MEAS1_CTRL1_AMP_RST_FB_FORCE(3)
+	esp.SENS.SetSAR_MEAS1_CTRL1_AMP_SHORT_REF_FORCE(3)
+	esp.SENS.SetSAR_MEAS1_CTRL1_AMP_SHORT_REF_GND_FORCE(3)
+
+	// SENS.SAR_AMP_CTRL1/2: amplifier/reference settling timings (same as cold-boot defaults).
+	esp.SENS.SetSAR_AMP_CTRL1_SAR_AMP_WAIT1(10)
+	esp.SENS.SetSAR_AMP_CTRL1_SAR_AMP_WAIT2(10)
+	esp.SENS.SetSAR_AMP_CTRL2_SAR_XPD_SAR_AMP_FSM_IDLE(1)
+	esp.SENS.SetSAR_AMP_CTRL2_SAR_AMP_SHORT_REF_GND_FSM_IDLE(1)
+
+	// ADC2 uses the same InitADC() as ADC1 (shared APB_SARADC clock/FSM).
+	// SENS.SAR_MEAS2_CTRL1: ADC2 FSM wait timings for power-up/reset/standby.
+	esp.SENS.SetSAR_MEAS2_CTRL1_SAR_SAR2_XPD_WAIT(8)
+	esp.SENS.SetSAR_MEAS2_CTRL1_SAR_SAR2_RSTB_WAIT(8)
+	esp.SENS.SetSAR_MEAS2_CTRL1_SAR_SAR2_STANDBY_WAIT(100)
+	esp.SENS.SetSAR_MEAS2_CTRL1_SAR_SAR2_RSTB_FORCE(3)
+
+	// SENS.SAR_MEAS1_MUX / SAR_MEAS1_CTRL2: route ADC1 to RTC controller and use SW to select channel/start.
+	esp.SENS.SetSAR_MEAS1_MUX_SAR1_DIG_FORCE(0)      // 0 = controlled by RTC/SENS, not digital/APB.
+	esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_FORCE(1) // SW triggers conversion.
+	esp.SENS.SetSAR_MEAS1_CTRL2_SAR1_EN_PAD_FORCE(1) // SW selects which ADC1 pad is enabled.
+
+	// APB_SARADC: shared FSM/clock config used by both ADC units and the ADC2 arbiter.
+	esp.APB_SARADC.SetFSM_WAIT_SARADC_XPD_WAIT(8)
+	esp.APB_SARADC.SetFSM_WAIT_SARADC_RSTB_WAIT(8)
+	esp.APB_SARADC.SetFSM_WAIT_SARADC_STANDBY_WAIT(100)
+	esp.APB_SARADC.SetCTRL_SARADC_XPD_SAR_FORCE(3)
+	esp.APB_SARADC.SetCTRL_SARADC_SAR_CLK_GATED(1)
+	esp.APB_SARADC.SetCTRL2_SARADC_SAR1_INV(0)
+	esp.APB_SARADC.SetCTRL2_SARADC_SAR2_INV(0)
+	esp.APB_SARADC.SetCLKM_CONF_CLK_SEL(2)
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_NUM(1)
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_B(0)
+	esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_A(0)
+	esp.APB_SARADC.SetCLKM_CONF_CLK_EN(1)
+	esp.APB_SARADC.SetFILTER_CTRL1_FILTER_FACTOR0(0)
+	esp.APB_SARADC.SetFILTER_CTRL1_FILTER_FACTOR1(0)
+
+	adcSelfCalibrate()
+	adcDigiRefMv = getDigiRef()
+}
+
+const (
+	attenDefault = 3 // 11 dB, ~0..3.3 V (IDF ADC_ATTEN_DB_12)
+)
+
+func setSensAtten1(ch, atten uint32) {
+	// SENS.SAR_ATTEN1: 2 bits per channel
+	v := esp.SENS.GetSAR_ATTEN1()
+	v &^= 3 << (ch * 2)
+	v |= (atten & 3) << (ch * 2)
+	esp.SENS.SetSAR_ATTEN1(v)
+}
+
+func setSensAtten2(ch, atten uint32) {
+	// SENS.SAR_ATTEN2: 2 bits per channel
+	v := esp.SENS.GetSAR_ATTEN2()
+	v &^= 3 << (ch * 2)
+	v |= (atten & 3) << (ch * 2)
+	esp.SENS.SetSAR_ATTEN2(v)
+}
+
+func (a ADC) Configure(config ADCConfig) error {
+	if a.Pin < 1 || a.Pin > 20 {
+		return errors.New("invalid ADC pin for ESP32-S3")
+	}
+	a.Pin.Configure(PinConfig{Mode: PinAnalog})
+
+	return nil
+}
+
+func (a ADC) Get() uint16 {
+	if a.Pin < 1 || a.Pin > 20 {
+		return 0
+	}
+
+	var ch uint32
+	var raw uint32
+	if a.Pin <= 10 {
+		ch = uint32(a.Pin - 1) // GPIO1→ch0 … GPIO10→ch9
+		esp.SENS.SetSAR_MEAS1_MUX_SAR1_DIG_FORCE(0)
+		esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_FORCE(1)
+		esp.SENS.SetSAR_MEAS1_CTRL2_SAR1_EN_PAD_FORCE(1)
+		setSensAtten1(ch, attenDefault)
+		esp.SENS.SetSAR_MEAS1_CTRL2_SAR1_EN_PAD(1 << ch)
+		for esp.SENS.GetSAR_SLAVE_ADDR1_SAR_SARADC_MEAS_STATUS() != 0 {
+		}
+		esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_SAR(0)
+		esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_SAR(1)
+		for esp.SENS.GetSAR_MEAS1_CTRL2_MEAS1_DONE_SAR() == 0 {
+		}
+		raw = esp.SENS.GetSAR_MEAS1_CTRL2_MEAS1_DATA_SAR()
+	} else {
+		ch = uint32(a.Pin - 11) // GPIO11→ch0 … GPIO20→ch9
+		// SENS.SAR_MEAS2_CTRL2: force SW control, select channel
+		esp.SENS.SetSAR_MEAS2_CTRL2_MEAS2_START_FORCE(1)
+		esp.SENS.SetSAR_MEAS2_CTRL2_SAR2_EN_PAD_FORCE(1)
+		esp.SENS.SetSAR_MEAS2_CTRL2_SAR2_EN_PAD(1 << ch)
+		setSensAtten2(ch, attenDefault)
+		// APB_SARADC.ARB_CTRL: grant ADC2 to APB for oneshot
+		esp.APB_SARADC.SetARB_CTRL_ADC_ARB_APB_FORCE(1)
+		esp.APB_SARADC.SetARB_CTRL_ADC_ARB_GRANT_FORCE(1)
+		// SENS.SAR_MEAS2_CTRL2.MEAS2_START_SAR: one-shot start
+		esp.SENS.SetSAR_MEAS2_CTRL2_MEAS2_START_SAR(0)
+		esp.SENS.SetSAR_MEAS2_CTRL2_MEAS2_START_SAR(1)
+		for esp.SENS.GetSAR_MEAS2_CTRL2_MEAS2_DONE_SAR() == 0 {
+		}
+		raw = esp.SENS.GetSAR_MEAS2_CTRL2_MEAS2_DATA_SAR()
+		esp.APB_SARADC.SetARB_CTRL_ADC_ARB_APB_FORCE(0)
+		esp.APB_SARADC.SetARB_CTRL_ADC_ARB_GRANT_FORCE(0)
+	}
+
+	return uint16(raw&0xfff) << 4
+}
+
+func (a ADC) GetVoltage() (raw uint32, v float64) {
+	const samples = 4
+	var sum uint32
+	for i := 0; i < samples; i++ {
+		sum += uint32(a.Get())
+	}
+	raw = sum / samples
+
+	// Default full-scale for 11 dB is approximately 3.3 V assuming
+	// Vref ≈ 1.1 V and gain ≈ 3. If eFuse provided a per-chip DIGI_REF
+	// (Vref in mV) via adcCalibration, use it to adjust the
+	// full-scale range instead.
+	scale := 3.3
+	if adcDigiRefMv != 0 {
+		scale = 3.0 * float64(adcDigiRefMv) / 1000.0
+	}
+
+	v = float64(raw) / 65520.0 * scale
+	return raw, v
+}
+
+// ADC hardware self-calibration for ESP32-S3.
+//
+// Mapping to ESP-IDF (adc_hal_common.c, hal/esp32s3/adc_ll.h):
+//   - adc_hal_self_calibration()      → ADCSelfCalibrate()
+//   - adc_ll_calibration_init()       → regI2C.calibrationInit (DREF=4);
+//                                      in IDF it is not called from self_cal, we call it explicitly.
+//   - adc_ll_calibration_prepare()    → SarEnable + calibrationPrepare (ENCAL_GND=1)
+//   - adc_ll_calibration_finish()     → calibrationFinish (ENCAL_GND=0)
+//   - adc_ll_set_calibration_param()  → setCalibrationParam()
+//   - read_cal_channel()              → adcCalibration.readADC1():
+//                                      wait for meas_status==0, start 0→1, wait done, read data
+//                                      (similar to adc_oneshot_ll_start + get_raw_result).
+//   - Loop: 10 iterations, code 0..4096, binary search on self_cal==0; drop min/max;
+//           rounding (remainder%8 < 4 without +1, otherwise +1) — same as in adc_hal_common.c.
+//   - raw_check_valid: for ADC1 in IDF always true — we do not check it.
+//
+// Differences:
+//   - regI2C: not ROM helper but direct access to 0x6000E000 (protocol like I2C_RTC_CONFIG2).
+//   - cal_setup: same SENS/atten/controller fields, but through our registers.
+//   - Result is stored only in hardware for the current session (not in eFuse).
+//   - eFuse V1: init_code and digi_ref are taken from eFuse — same idea as Arduino/IDF.
+
+const (
+	adcCalTimes     = 10
+	adcCalRtcMagic  = uint32(0xADC1C401)
+	adcCalInitMin   = uint32(2000)
+	adcCalInitMax   = uint32(3900)
+	adcDigiRefMinMv = uint32(920)
+	adcDigiRefMaxMv = uint32(1150)
+)
+
+// adcCalibration encapsulates the self-calibration flow for ADC1
+// and remembers per-chip calibration data (such as DIGI_REF) when it is
+// available from eFuse.
+func adcSelfCalibrate() {
+	reg := newRegI2C()
+	f := fuse{}
+
+	if vref, ok := f.adc1DigiRefAtten3(); ok {
+		adcDigiRefMv = vref
+	}
+
+	if saved, ok := restoreFromRTC(); ok {
+		reg.sarEnable()
+		reg.calibrationInit(0)
+		adc1CalibrateHigh(reg, saved)
+		return
+	}
+
+	initCode, useEfuse := f.adc1InitCodeAtten3()
+	adc1CalibrationSetup(reg)
+
+	if useEfuse {
+		saveToRTC(initCode)
+		adc1CalibrateHigh(reg, initCode)
+		return
+	}
+
+	finalCode := reg.calibrateBinarySearch(0, adcCalTimes, readADC1)
+	saveToRTC(finalCode)
+	adc1CalibrateHigh(reg, finalCode)
+}
+
+func getDigiRef() uint32 {
+	return adcDigiRefMv
+}
+
+func adc1CalibrationSetup(reg regI2C) {
+	reg.sarEnable()
+
+	esp.SENS.SetSAR_MEAS1_MUX_SAR1_DIG_FORCE(0)
+	esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_FORCE(0)
+	esp.SENS.SetSAR_MEAS2_CTRL2_MEAS2_START_FORCE(0)
+	esp.SENS.SetSAR_MEAS1_CTRL2_SAR1_EN_PAD(0)
+	setSensAtten1(0, attenDefault)
+	esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_FORCE(1)
+	esp.SENS.SetSAR_MEAS1_CTRL2_SAR1_EN_PAD_FORCE(1)
+
+	reg.calibrationInit(0)
+	reg.calibrationPrepare(0)
+}
+
+func adc1CalibrateHigh(reg regI2C, code uint32) {
+	reg.setCalibrationParam(0, code)
+	reg.calibrationFinish(0)
+	adc1StartWithPadForce()
+}
+
+func adc1StartWithPadForce() {
+	esp.SENS.SetSAR_MEAS1_CTRL2_SAR1_EN_PAD_FORCE(1)
+	esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_FORCE(1)
+}
+
+// readADC1 performs one ADC1 conversion via RTC path (used during calibration).
+// Internal GND is connected via ENCAL_GND, so the pin input is disconnected.
+// Matches IDF: wait conversion idle (meas_status==0), then start 0→1, wait done, read data.
+func readADC1() uint32 {
+	for esp.SENS.GetSAR_SLAVE_ADDR1_SAR_SARADC_MEAS_STATUS() != 0 {
+	}
+	esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_SAR(0)
+	esp.SENS.SetSAR_MEAS1_CTRL2_MEAS1_START_SAR(1)
+	for esp.SENS.GetSAR_MEAS1_CTRL2_MEAS1_DONE_SAR() == 0 {
+	}
+	return uint32(esp.SENS.GetSAR_MEAS1_CTRL2_MEAS1_DATA_SAR() & 0xfff)
+}
+
+func restoreFromRTC() (uint32, bool) {
+	if esp.RTC_CNTL.GetSTORE0() != adcCalRtcMagic {
+		return 0, false
+	}
+	code := esp.RTC_CNTL.GetSTORE1()
+	if code < adcCalInitMin || code > adcCalInitMax {
+		return 0, false
+	}
+	return code, true
+}
+
+func saveToRTC(code uint32) {
+	esp.RTC_CNTL.SetSTORE0(adcCalRtcMagic)
+	esp.RTC_CNTL.SetSTORE1(code)
+}
+
+// fuse
+const (
+	// Base address for eFuse controller (EFUSE_BLKx region in TRM).
+	efuseBase = uintptr(0x60007000)
+
+	// EFUSE_*_REG offsets mirror ESP-IDF's efuse_reg.h layout.
+	efuseClkReg        = efuseBase + 0x1c8
+	efuseConfReg       = efuseBase + 0x1cc
+	efuseCmdReg        = efuseBase + 0x1d4
+	efuseDacConfReg    = efuseBase + 0x1e8
+	efuseWrTimConf1Reg = efuseBase + 0x1f4
+	efuseWrTimConf2Reg = efuseBase + 0x1f8
+	efuseRdData4Reg    = efuseBase + 0x6c // EFUSE_RD_WR_DIS_REG / RD_DATA4
+	efuseRdData5Reg    = efuseBase + 0x70 // EFUSE_RD_REPEAT_DATA1_REG / RD_DATA5
+	efuseRdData7Reg    = efuseBase + 0x78 // EFUSE_RD_REPEAT_DATA3_REG / RD_DATA7
+
+	// Read opcode and clock enable bit used by EFUSE HAL (see efuse_ll).
+	efuseReadOpCode   = uint32(0x5AA5)
+	efuseClkEnBit     = uint32(1 << 16)
+	efuseBlkVersionV1 = 1 // EFUSE_BLK_VERSION major version = 1
+
+	// SYSTEM_PERIP_CLK_EN0 register and EFUSE clock gate bit.
+	systemPeripClkEn0   = uintptr(0x600C0018)
+	systemEfuseClkEnBit = uint32(1 << 14)
+)
+
+type fuse struct{}
+
+// adc1InitCodeAtten3 extracts the ADC1 INIT_CODE (offset trim) for
+// attenuation index 3 (typically 11 dB) from EFUSE_BLK2. This mirrors
+// the logic used by ESP-IDF's ADC calibration HAL for ESP32-S3.
+//
+// The code is built from four differential eFuse fields (diff0..diff3)
+// and constant offsets (1850, 90, 70) as described in Espressif's
+// internal calibration formulas.
+func (f *fuse) adc1InitCodeAtten3() (uint32, bool) {
+	for try := 0; try < 2; try++ {
+		f.triggerReadSequence()
+		data4, data5, blkVer := f.readBlock2Data4Data5()
+		if blkVer != efuseBlkVersionV1 {
+			continue
+		}
+		diff0 := (data4 >> 21) & 0xFF
+		diff1 := (data4 >> 29) | ((data5 & 7) << 3)
+		diff2 := (data5 >> 3) & 0x3F
+		diff3 := (data5 >> 9) & 0x3F
+		icode0 := diff0 + 1850
+		icode1 := diff1 + icode0 + 90
+		icode2 := diff2 + icode1
+		icode3 := diff3 + icode2 + 70
+		if icode3 >= adcCalInitMin && icode3 <= adcCalInitMax {
+			return icode3, true
+		}
+	}
+	return 0, false
+}
+
+// adc1DigiRefAtten3 reads the digital reference (DIGI_REF) for
+// ADC1 at attenuation index 3 from EFUSE_BLK2 / RD_DATA7. This is
+// similar to what the ESP-IDF ADC calibration HAL uses when present.
+func (f *fuse) adc1DigiRefAtten3() (uint32, bool) {
+	f.triggerReadSequence()
+	_, _, blkVer := f.readBlock2Data4Data5()
+	if blkVer != efuseBlkVersionV1 {
+		return 0, false
+	}
+	data7 := f.readBlock2Data7()
+	diff3 := (data7 >> 1) & 0xFF
+	digiRef := diff3 + 900
+	if digiRef < adcDigiRefMinMv || digiRef > adcDigiRefMaxMv {
+		return 0, false
+	}
+	return digiRef, true
+}
+
+// triggerReadSequence performs one eFuse read operation using the
+// controller's timing/opcode sequence. This roughly corresponds to
+// the low-level logic in the ESP-IDF eFuse HAL (see efuse_ll_* in
+// the IDF sources and the "eFuse Manager" docs:
+// https://docs.espressif.com/projects/esp-idf/en/latest/esp32s3/api-reference/system/efuse.html).
+func (f *fuse) triggerReadSequence() {
+	clk := (*volatile.Register32)(unsafe.Pointer(systemPeripClkEn0))
+	clk.Set(clk.Get() | systemEfuseClkEnBit)
+	efuseClk := (*volatile.Register32)(unsafe.Pointer(efuseClkReg))
+	efuseClk.Set(efuseClk.Get() | efuseClkEnBit)
+	dac := (*volatile.Register32)(unsafe.Pointer(efuseDacConfReg))
+	dac.Set(0x28 | (0xFF << 9))
+	(*volatile.Register32)(unsafe.Pointer(efuseWrTimConf1Reg)).Set(0x3000 << 8)
+	(*volatile.Register32)(unsafe.Pointer(efuseWrTimConf2Reg)).Set(0x190)
+	(*volatile.Register32)(unsafe.Pointer(efuseConfReg)).Set(efuseReadOpCode)
+	cmd := (*volatile.Register32)(unsafe.Pointer(efuseCmdReg))
+	cmd.Set(1)
+	for cmd.Get()&1 != 0 {
+	}
+}
+
+// readBlock2Data4Data5 reads the EFUSE_BLK2 data words that contain
+// ADC calibration and version information. It returns RD_DATA4,
+// RD_DATA5 and the decoded block version (BLK_VERSION).
+//
+// Layout is derived from the ESP32-S3 TRM and IDF eFuse tables.
+func (f *fuse) readBlock2Data4Data5() (data4, data5 uint32, blkVer uint8) {
+	data4 = (*volatile.Register32)(unsafe.Pointer(efuseRdData4Reg)).Get()
+	data5 = (*volatile.Register32)(unsafe.Pointer(efuseRdData5Reg)).Get()
+	blkVer = uint8(data4 & 3)
+	return data4, data5, blkVer
+}
+
+// readBlock2Data7 reads RD_DATA7 from EFUSE_BLK2, which for ADC
+// calibration contains additional reference (DIGI_REF) data fields.
+func (f *fuse) readBlock2Data7() uint32 {
+	return (*volatile.Register32)(unsafe.Pointer(efuseRdData7Reg)).Get()
+}
+
+// readAdcCalibBlock2 triggers an eFuse read and returns the raw
+// EFUSE_BLK2 words used for ADC calibration (RD_DATA4/5) along
+// with the decoded block version. This is a small helper similar
+// in spirit to the internal IDF helpers around EFUSE_BLK2.
+func (f *fuse) readAdcCalibBlock2() (data4, data5 uint32, blkVer uint8) {
+	f.triggerReadSequence()
+	return f.readBlock2Data4Data5()
+}

src/machine/machine_esp32s3_i2c.go

@@ -0,0 +1,35 @@
+//go:build esp32s3
+
+package machine
+
+import (
+	"device/esp"
+)
+
+const (
+	I2CEXT0_SCL_OUT_IDX = 89
+	I2CEXT0_SDA_OUT_IDX = 90
+	I2CEXT1_SCL_OUT_IDX = 91
+	I2CEXT1_SDA_OUT_IDX = 92
+)
+
+var (
+	I2C0 = &I2C{
+		Bus:     esp.I2C0,
+		funcSCL: I2CEXT0_SCL_OUT_IDX,
+		funcSDA: I2CEXT0_SDA_OUT_IDX,
+		useExt1: false,
+	}
+	I2C1 = &I2C{
+		Bus:     esp.I2C1,
+		funcSCL: I2CEXT1_SCL_OUT_IDX,
+		funcSDA: I2CEXT1_SDA_OUT_IDX,
+		useExt1: true,
+	}
+)
+
+func initI2CExt1Clock() {
+	esp.SYSTEM.SetPERIP_RST_EN0_I2C_EXT1_RST(1)
+	esp.SYSTEM.SetPERIP_CLK_EN0_I2C_EXT1_CLK_EN(1)
+	esp.SYSTEM.SetPERIP_RST_EN0_I2C_EXT1_RST(0)
+}

src/machine/machine_esp32s3_pwm.go

@@ -0,0 +1,226 @@
+//go:build esp32s3
+
+package machine
+
+import "device/esp"
+
+// LEDC PWM for ESP32-S3: 4 timers (PWM0–PWM3), 8 channels per timer; each timer has its own frequency.
+// Range: frequency from a few Hz up to ~40 MHz (at 1-bit resolution); duty resolution 1–15 bits
+// (higher frequency gives lower resolution). Clock source: APB 80 MHz. Low-speed mode only.
+// Duty must not equal 2^resolution (overflow risk). See ESP-IDF LEDC driver, TRM LED PWM Controller.
+
+// GPIO matrix output signal indices for LEDC (soc/gpio_sig_map.h)
+const (
+	LEDC_LS_SIG_OUT0_IDX = 73
+)
+
+const ledcChannelsS3 = 8
+
+var (
+	PWM0 = &LEDCPWM{SigOutBase: LEDC_LS_SIG_OUT0_IDX, NumChannels: ledcChannelsS3, timerNum: 0}
+	PWM1 = &LEDCPWM{SigOutBase: LEDC_LS_SIG_OUT0_IDX, NumChannels: ledcChannelsS3, timerNum: 1}
+	PWM2 = &LEDCPWM{SigOutBase: LEDC_LS_SIG_OUT0_IDX, NumChannels: ledcChannelsS3, timerNum: 2}
+	PWM3 = &LEDCPWM{SigOutBase: LEDC_LS_SIG_OUT0_IDX, NumChannels: ledcChannelsS3, timerNum: 3}
+)
+
+// chanOp implements LEDC low-speed channel ops for ESP32-S3 (channels 0–7).
+func (pwm *LEDCPWM) chanOp(ch uint8, op ledcChanOp, duty uint32, inverting bool) {
+	invVal := uint32(0)
+	if inverting {
+		invVal = 1
+	}
+	switch ch {
+	case 0:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH0_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH0_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH0_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH0_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH0_DUTY_DUTY(0)
+			esp.LEDC.SetCH0_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH0_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH0_DUTY_DUTY(duty)
+			esp.LEDC.SetCH0_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH0_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH0_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH0_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH0_CONF0_IDLE_LV(invVal)
+		}
+	case 1:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH1_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH1_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH1_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH1_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH1_DUTY_DUTY(0)
+			esp.LEDC.SetCH1_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH1_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH1_DUTY_DUTY(duty)
+			esp.LEDC.SetCH1_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH1_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH1_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH1_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH1_CONF0_IDLE_LV(invVal)
+		}
+	case 2:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH2_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH2_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH2_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH2_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH2_DUTY_DUTY(0)
+			esp.LEDC.SetCH2_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH2_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH2_DUTY_DUTY(duty)
+			esp.LEDC.SetCH2_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH2_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH2_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH2_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH2_CONF0_IDLE_LV(invVal)
+		}
+	case 3:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH3_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH3_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH3_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH3_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH3_DUTY_DUTY(0)
+			esp.LEDC.SetCH3_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH3_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH3_DUTY_DUTY(duty)
+			esp.LEDC.SetCH3_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH3_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH3_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH3_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH3_CONF0_IDLE_LV(invVal)
+		}
+	case 4:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH4_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH4_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH4_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH4_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH4_DUTY_DUTY(0)
+			esp.LEDC.SetCH4_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH4_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH4_DUTY_DUTY(duty)
+			esp.LEDC.SetCH4_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH4_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH4_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH4_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH4_CONF0_IDLE_LV(invVal)
+		}
+	case 5:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH5_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH5_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH5_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH5_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH5_DUTY_DUTY(0)
+			esp.LEDC.SetCH5_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH5_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH5_DUTY_DUTY(duty)
+			esp.LEDC.SetCH5_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH5_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH5_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH5_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH5_CONF0_IDLE_LV(invVal)
+		}
+	case 6:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH6_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH6_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH6_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH6_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH6_DUTY_DUTY(0)
+			esp.LEDC.SetCH6_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH6_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH6_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH6_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH6_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH6_DUTY_DUTY(duty)
+			esp.LEDC.SetCH6_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH6_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH6_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH6_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH6_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH6_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH6_CONF0_IDLE_LV(invVal)
+		}
+	case 7:
+		switch op {
+		case ledcChanOpInit:
+			esp.LEDC.SetCH7_CONF0_TIMER_SEL(uint32(pwm.timerNum))
+			esp.LEDC.SetCH7_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH7_CONF0_IDLE_LV(0)
+			esp.LEDC.SetCH7_HPOINT_HPOINT(0)
+			esp.LEDC.SetCH7_DUTY_DUTY(0)
+			esp.LEDC.SetCH7_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH7_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH7_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH7_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH7_CONF0_PARA_UP(1)
+		case ledcChanOpSetDuty:
+			esp.LEDC.SetCH7_DUTY_DUTY(duty)
+			esp.LEDC.SetCH7_CONF1_DUTY_CYCLE(1)
+			esp.LEDC.SetCH7_CONF1_DUTY_NUM(1)
+			esp.LEDC.SetCH7_CONF1_DUTY_INC(1)
+			esp.LEDC.SetCH7_CONF1_DUTY_START(1)
+			esp.LEDC.SetCH7_CONF0_SIG_OUT_EN(1)
+			esp.LEDC.SetCH7_CONF0_PARA_UP(1)
+		case ledcChanOpSetInvert:
+			esp.LEDC.SetCH7_CONF0_IDLE_LV(invVal)
+		}
+	}
+}

src/machine/machine_esp32s3_spi.go

@@ -15,11 +15,6 @@ import (
 )
 
 const (
-	SPI_MODE0 = uint8(0)
-	SPI_MODE1 = uint8(1)
-	SPI_MODE2 = uint8(2)
-	SPI_MODE3 = uint8(3)
-
 	// ESP32-S3 PLL clock frequency (same as ESP32-C3)
 	pplClockFreq = 80e6
 
@@ -64,16 +59,6 @@ var (
 	SPI1 = &SPI{Bus: esp.SPI3, busID: 3} // Secondary SPI (HSPI)
 )
 
-type SPIConfig struct {
-	Frequency uint32
-	SCK       Pin   // Serial Clock
-	SDO       Pin   // Serial Data Out (MOSI)
-	SDI       Pin   // Serial Data In  (MISO)
-	CS        Pin   // Chip Select (optional)
-	LSBFirst  bool  // MSB is default
-	Mode      uint8 // SPI_MODE0 is default
-}
-
 // Configure and make the SPI peripheral ready to use.
 // Implementation following ESP-IDF HAL with GPIO Matrix routing
 func (spi *SPI) Configure(config SPIConfig) error {
@@ -82,6 +67,12 @@ func (spi *SPI) Configure(config SPIConfig) error {
 		config.Frequency = SPI_DEFAULT_FREQUENCY
 	}
 
+	// Default CS to NoPin so that an unset CS field (zero value = GPIO0)
+	// does not accidentally configure GPIO0 as the chip select output.
+	if config.CS == 0 {
+		config.CS = NoPin
+	}
+
 	switch spi.busID {
 	case 2: // SPI2 (FSPI)
 		if config.SCK == 0 {
@@ -232,14 +223,14 @@ func (spi *SPI) Configure(config SPIConfig) error {
 
 	// Configure SPI mode (CPOL/CPHA) following ESP-IDF HAL
 	switch config.Mode {
-	case SPI_MODE0:
+	case Mode0:
 		// CPOL=0, CPHA=0 (default)
-	case SPI_MODE1:
+	case Mode1:
 		bus.SetUSER_CK_OUT_EDGE(1) // CPHA=1
-	case SPI_MODE2:
+	case Mode2:
 		bus.SetMISC_CK_IDLE_EDGE(1) // CPOL=1
 		bus.SetUSER_CK_OUT_EDGE(1)  // CPHA=1
-	case SPI_MODE3:
+	case Mode3:
 		bus.SetMISC_CK_IDLE_EDGE(1) // CPOL=1
 	}
 
@@ -319,36 +310,7 @@ func (spi *SPI) Tx(w, r []byte) error {
 
 		// Fill tx buffer.
 		transferWords := (*[16]volatile.Register32)(unsafe.Add(unsafe.Pointer(&bus.W0), 0))
-		if len(w) >= 64 {
-			// We can fill the entire 64-byte transfer buffer with data.
-			// This loop is slightly faster than the loop below.
-			for i := 0; i < 16; i++ {
-				word := uint32(w[i*4]) | uint32(w[i*4+1])<<8 | uint32(w[i*4+2])<<16 | uint32(w[i*4+3])<<24
-				transferWords[i].Set(word)
-			}
-		} else {
-			// We can't fill the entire transfer buffer, so we need to be a bit
-			// more careful.
-			// Note that parts of the transfer buffer that aren't used still
-			// need to be set to zero, otherwise we might be transferring
-			// garbage from a previous transmission if w is smaller than r.
-			for i := 0; i < 16; i++ {
-				var word uint32
-				if i*4+3 < len(w) {
-					word |= uint32(w[i*4+3]) << 24
-				}
-				if i*4+2 < len(w) {
-					word |= uint32(w[i*4+2]) << 16
-				}
-				if i*4+1 < len(w) {
-					word |= uint32(w[i*4+1]) << 8
-				}
-				if i*4+0 < len(w) {
-					word |= uint32(w[i*4+0]) << 0
-				}
-				transferWords[i].Set(word)
-			}
-		}
+		spiTxFillBuffer(transferWords, w)
 
 		// Do the transfer.
 		bus.SetMS_DLEN_MS_DATA_BITLEN(uint32(chunkSize)*8 - 1)
@@ -388,58 +350,6 @@ func (spi *SPI) Tx(w, r []byte) error {
 	return nil
 }
 
-// Compute the SPI bus frequency from the APB clock frequency.
-// Note: APB clock is always 80MHz on ESP32-S3, independent of CPU frequency.
-// Ported from ESP32-C3 implementation for better accuracy.
-func freqToClockDiv(hz uint32) uint32 {
-	// Use APB clock frequency (80MHz), not CPU frequency!
-	// SPI peripheral is connected to APB bus which stays at 80MHz
-	const apbFreq = pplClockFreq // 80MHz
-
-	if hz >= apbFreq { // maximum frequency
-		return 1 << 31
-	}
-	if hz < (apbFreq / (16 * 64)) { // minimum frequency
-		return 15<<18 | 63<<12 | 31<<6 | 63 // pre=15, n=63
-	}
-
-	// iterate looking for an exact match
-	// or iterate all 16 prescaler options
-	// looking for the smallest error
-	var bestPre, bestN, bestErr uint32
-	bestN = 1
-	bestErr = 0xffffffff
-	q := uint32(float32(apbFreq)/float32(hz) + float32(0.5))
-	for p := uint32(0); p < 16; p++ {
-		n := q/(p+1) - 1
-		if n < 1 { // prescaler became too large, stop enum
-			break
-		}
-		if n > 63 { // prescaler too small, skip to next
-			continue
-		}
-
-		freq := apbFreq / ((p + 1) * (n + 1))
-		if freq == hz { // exact match
-			return p<<18 | n<<12 | (n/2)<<6 | n
-		}
-
-		var err uint32
-		if freq < hz {
-			err = hz - freq
-		} else {
-			err = freq - hz
-		}
-		if err < bestErr {
-			bestErr = err
-			bestPre = p
-			bestN = n
-		}
-	}
-
-	return bestPre<<18 | bestN<<12 | (bestN/2)<<6 | bestN
-}
-
 // isDefaultSPIPins checks if the given pins match the default SPI pin configuration
 // that supports IO MUX direct connection for better performance
 func isDefaultSPIPins(busID uint8, config SPIConfig) bool {

src/machine/machine_esp32xx_adc.go

@@ -0,0 +1,235 @@
+//go:build esp32s3 || (esp32c3 && !m5stamp_c3)
+
+// Shared regI2C-based ADC calibration helpers for ESP32-S3 and ESP32-C3.
+//
+// The internal I2C bus ("regI2C") and SAR ADC trim register layout are
+// identical across both chips; chip-specific differences (host ID, DREF
+// init value, calibration iterations) are captured in the regI2C struct
+// fields, keeping each target file free of duplicated low-level code.
+
+package machine
+
+import (
+	"device/esp"
+	"runtime/volatile"
+	"unsafe"
+)
+
+// regI2C wraps the internal I2C bus used for SAR ADC calibration registers.
+// Fields hold chip-specific parameters that differ between ESP32-S3 and ESP32-C3.
+type regI2C struct {
+	// hostID is the I2C_SAR_ADC_HOSTID (1 for ESP32-S3, 0 for ESP32-C3).
+	hostID uint8
+	// drefInit is the DREF reference value written during calibrationInit
+	// (4 for ESP32-S3, 1 for ESP32-C3).
+	drefInit uint8
+}
+
+// SAR ADC I2C register layout constants shared across ESP32-S3 and ESP32-C3.
+// Source: ESP-IDF soc/regi2c_saradc.h
+const (
+	// i2cSarADC is the I2C_SAR_ADC block address on the internal bus.
+	i2cSarADC = uint8(0x69)
+
+	// DREF (reference) bitfields for ADC1 and ADC2.
+	adc1DrefAddr = uint8(0x2)
+	adc1DrefMSB  = uint8(6)
+	adc1DrefLSB  = uint8(4)
+	adc2DrefAddr = uint8(0x5)
+	adc2DrefMSB  = uint8(6)
+	adc2DrefLSB  = uint8(4)
+
+	// ENCAL_GND: routes internal ground to ADC input during self-calibration.
+	adc1EncalGndAddr = uint8(0x7)
+	adc1EncalGndMSB  = uint8(5)
+	adc1EncalGndLSB  = uint8(5)
+	adc2EncalGndAddr = uint8(0x7)
+	adc2EncalGndMSB  = uint8(7)
+	adc2EncalGndLSB  = uint8(7)
+
+	// INIT_CODE (offset) high/low for ADC1 and ADC2.
+	adc1InitCodeHighAddr = uint8(0x1)
+	adc1InitCodeHighMSB  = uint8(3)
+	adc1InitCodeHighLSB  = uint8(0)
+	adc1InitCodeLowAddr  = uint8(0x0)
+	adc1InitCodeLowMSB   = uint8(7)
+	adc1InitCodeLowLSB   = uint8(0)
+	adc2InitCodeHighAddr = uint8(0x4)
+	adc2InitCodeHighMSB  = uint8(3)
+	adc2InitCodeHighLSB  = uint8(0)
+	adc2InitCodeLowAddr  = uint8(0x3)
+	adc2InitCodeLowMSB   = uint8(7)
+	adc2InitCodeLowLSB   = uint8(0)
+
+	// ANA_CONFIG / ANA_CONFIG2: enable analog SAR I2C domain.
+	anaConfigReg  = uintptr(0x6000E044)
+	i2cSarEnMask  = uint32(1 << 18)
+	anaConfig2Reg = uintptr(0x6000E048)
+	anaSarCfg2En  = uint32(1 << 16)
+
+	// REGI2C master control register and helper masks.
+	i2cMstCtrlReg     = uintptr(0x6000E000)
+	i2cMstBusyBit     = uint32(1 << 25)
+	i2cMstWrCntlBit   = uint32(1 << 24)
+	i2cMstDataMask    = uint32(0xFF << 16)
+	i2cMstDataShift   = 16
+	i2cMstBusyTimeout = 10000
+
+	// adcCalOffsetRange is the binary search upper bound (12-bit full scale).
+	adcCalOffsetRange = uint32(4096)
+
+	// adcCalMaxIterations is the maximum number of calibration iterations
+	// supported by calibrateBinarySearch. Must be >= max(S3=10, C3=15).
+	adcCalMaxIterations = 16
+)
+
+// waitIdle polls the REGI2C master BUSY bit until it clears or a
+// timeout expires, matching the busy-wait helper in ESP-IDF's regi2c_ctrl.c.
+func (r regI2C) waitIdle(reg *volatile.Register32) bool {
+	for i := 0; i < i2cMstBusyTimeout; i++ {
+		if reg.Get()&i2cMstBusyBit == 0 {
+			return true
+		}
+	}
+	return false
+}
+
+// writeMask is a software implementation of the IDF REGI2C_WRITE_MASK macro.
+// It reads the current byte at regAddr on the SAR ADC I2C block, updates
+// only the [msb:lsb] bitfield, and writes it back via the internal I2C master.
+func (r regI2C) writeMask(regAddr, msb, lsb, data uint8) {
+	reg := (*volatile.Register32)(unsafe.Pointer(i2cMstCtrlReg))
+	if !r.waitIdle(reg) {
+		return
+	}
+	reg.Set(uint32(i2cSarADC) | uint32(regAddr)<<8)
+	if !r.waitIdle(reg) {
+		return
+	}
+	cur := (reg.Get() & i2cMstDataMask) >> i2cMstDataShift
+	mask := uint32(1<<(msb-lsb+1)-1) << lsb
+	cur &^= mask
+	cur |= uint32(data&(1<<(msb-lsb+1)-1)) << lsb
+	reg.Set(uint32(i2cSarADC) | uint32(regAddr)<<8 | i2cMstWrCntlBit | (cur<<i2cMstDataShift)&i2cMstDataMask)
+	r.waitIdle(reg)
+}
+
+// sarEnable enables the analog SAR I2C domain before any regI2C access,
+// matching the prologue in adc_ll_calibration_prepare().
+func (r regI2C) sarEnable() {
+	cfg := (*volatile.Register32)(unsafe.Pointer(anaConfigReg))
+	cfg2 := (*volatile.Register32)(unsafe.Pointer(anaConfig2Reg))
+	esp.RTC_CNTL.SetANA_CONF_SAR_I2C_PU(1)
+	cfg.Set(cfg.Get() &^ i2cSarEnMask)
+	cfg2.Set(cfg2.Get() | anaSarCfg2En)
+}
+
+// calibrationInit sets the DREF reference for the selected ADC unit to
+// the chip-specific init value before running self-calibration.
+// Corresponds to adc_ll_calibration_init() in ESP-IDF.
+func (r regI2C) calibrationInit(adcN uint8) {
+	if adcN == 0 {
+		r.writeMask(adc1DrefAddr, adc1DrefMSB, adc1DrefLSB, r.drefInit)
+	} else {
+		r.writeMask(adc2DrefAddr, adc2DrefMSB, adc2DrefLSB, r.drefInit)
+	}
+}
+
+// calibrationPrepare enables ENCAL_GND so that the ADC input is
+// internally shorted to ground during self-calibration.
+// Corresponds to the ENCAL_GND part of adc_ll_calibration_prepare().
+func (r regI2C) calibrationPrepare(adcN uint8) {
+	if adcN == 0 {
+		r.writeMask(adc1EncalGndAddr, adc1EncalGndMSB, adc1EncalGndLSB, 1)
+	} else {
+		r.writeMask(adc2EncalGndAddr, adc2EncalGndMSB, adc2EncalGndLSB, 1)
+	}
+}
+
+// calibrationFinish clears ENCAL_GND to reconnect the ADC input to the
+// external pad after self-calibration.
+// Corresponds to adc_ll_calibration_finish() in ESP-IDF.
+func (r regI2C) calibrationFinish(adcN uint8) {
+	if adcN == 0 {
+		r.writeMask(adc1EncalGndAddr, adc1EncalGndMSB, adc1EncalGndLSB, 0)
+	} else {
+		r.writeMask(adc2EncalGndAddr, adc2EncalGndMSB, adc2EncalGndLSB, 0)
+	}
+}
+
+// setCalibrationParam writes the INIT_CODE (offset trim) for the selected
+// ADC unit via the regI2C bitfields.
+// Corresponds to adc_ll_set_calibration_param() in ESP-IDF.
+func (r regI2C) setCalibrationParam(adcN uint8, param uint32) {
+	msb := uint8(param >> 8)
+	lsb := uint8(param & 0xFF)
+	if adcN == 0 {
+		r.writeMask(adc1InitCodeHighAddr, adc1InitCodeHighMSB, adc1InitCodeHighLSB, msb)
+		r.writeMask(adc1InitCodeLowAddr, adc1InitCodeLowMSB, adc1InitCodeLowLSB, lsb)
+	} else {
+		r.writeMask(adc2InitCodeHighAddr, adc2InitCodeHighMSB, adc2InitCodeHighLSB, msb)
+		r.writeMask(adc2InitCodeLowAddr, adc2InitCodeLowMSB, adc2InitCodeLowLSB, lsb)
+	}
+}
+
+// calibrateBinarySearch runs the ADC self-calibration binary search loop.
+// It performs 'iterations' rounds of binary search to find the optimal offset
+// code, drops the min/max outliers, and returns the rounded mean of the
+// remaining values. This matches adc_hal_self_calibration() in ESP-IDF.
+//
+// The readADC callback must perform a single conversion using the target's
+// oneshot path (SENS or APB_SARADC) and return the raw 12-bit result.
+// During calibration, ENCAL_GND is active so the ADC reads its internal ground.
+func (r regI2C) calibrateBinarySearch(adcN uint8, iterations int, readADC func() uint32) uint32 {
+	if iterations > adcCalMaxIterations {
+		iterations = adcCalMaxIterations
+	}
+	var codeList [adcCalMaxIterations]uint32
+	var codeSum uint32
+
+	for rpt := 0; rpt < iterations; rpt++ {
+		codeH := adcCalOffsetRange
+		codeL := uint32(0)
+		chkCode := (codeH + codeL) / 2
+		r.setCalibrationParam(adcN, chkCode)
+		selfCal := readADC()
+
+		for codeH-codeL > 1 {
+			if selfCal == 0 {
+				codeH = chkCode
+			} else {
+				codeL = chkCode
+			}
+			chkCode = (codeH + codeL) / 2
+			r.setCalibrationParam(adcN, chkCode)
+			selfCal = readADC()
+			if codeH-codeL == 1 {
+				chkCode++
+				r.setCalibrationParam(adcN, chkCode)
+				selfCal = readADC()
+			}
+		}
+		codeList[rpt] = chkCode
+		codeSum += chkCode
+	}
+
+	// Drop min and max outliers, then average with IDF-style rounding.
+	codeMin := codeList[0]
+	codeMax := codeList[0]
+	for i := 0; i < iterations; i++ {
+		if codeList[i] < codeMin {
+			codeMin = codeList[i]
+		}
+		if codeList[i] > codeMax {
+			codeMax = codeList[i]
+		}
+	}
+	remaining := codeSum - codeMax - codeMin
+	divisor := uint32(iterations - 2)
+	finalCode := remaining / divisor
+	if remaining%divisor >= 4 {
+		finalCode++
+	}
+
+	return finalCode
+}

src/machine/machine_esp32xx_i2c.go

@@ -0,0 +1,336 @@
+//go:build (esp32c3 || esp32s3) && !m5stamp_c3
+
+package machine
+
+import (
+	"device/esp"
+	"runtime/volatile"
+	"unsafe"
+)
+
+type I2C struct {
+	Bus              *esp.I2C_Type
+	funcSCL, funcSDA uint32
+	useExt1          bool
+	txCmdBuf         [8]i2cCommand
+}
+
+// I2CConfig is used to store config info for I2C.
+type I2CConfig struct {
+	Frequency uint32 // in Hz
+	SCL       Pin
+	SDA       Pin
+}
+
+const (
+	clkXTAL               = 0
+	clkFOSC               = 1
+	clkXTALFrequency      = uint32(40e6)
+	clkFOSCFrequency      = uint32(17.5e6)
+	i2cClkSourceFrequency = clkXTALFrequency
+	i2cClkSource          = clkXTAL
+)
+
+func (i2c *I2C) Configure(config I2CConfig) error {
+	if config.Frequency == 0 {
+		config.Frequency = 400 * KHz
+	}
+	if config.SCL == 0 {
+		config.SCL = SCL_PIN
+	}
+	if config.SDA == 0 {
+		config.SDA = SDA_PIN
+	}
+
+	i2c.initClock(config)
+	i2c.initNoiseFilter()
+	i2c.initPins(config)
+	i2c.initFrequency(config)
+	i2c.startMaster()
+	return nil
+}
+
+//go:inline
+func (i2c *I2C) initClock(config I2CConfig) {
+	if !i2c.useExt1 {
+		esp.SYSTEM.SetPERIP_RST_EN0_I2C_EXT0_RST(1)
+		esp.SYSTEM.SetPERIP_CLK_EN0_I2C_EXT0_CLK_EN(1)
+		esp.SYSTEM.SetPERIP_RST_EN0_I2C_EXT0_RST(0)
+	} else {
+		initI2CExt1Clock()
+	}
+	// disable interrupts
+	i2c.Bus.INT_CLR.Set(0x3fff)
+	i2c.Bus.INT_ENA.ClearBits(0x3fff)
+
+	i2c.Bus.SetCLK_CONF_SCLK_SEL(i2cClkSource)
+	i2c.Bus.SetCLK_CONF_SCLK_ACTIVE(1)
+	i2c.Bus.SetCLK_CONF_SCLK_DIV_NUM(i2cClkSourceFrequency / (config.Frequency * 1024))
+	i2c.Bus.SetCTR_CLK_EN(1)
+}
+
+//go:inline
+func (i2c *I2C) initNoiseFilter() {
+	i2c.Bus.FILTER_CFG.Set(0x377)
+}
+
+//go:inline
+func (i2c *I2C) initPins(config I2CConfig) {
+	config.SDA.configure(PinConfig{Mode: PinOutput}, i2c.funcSDA)
+	inFunc(i2c.funcSDA).Set(esp.GPIO_FUNC_IN_SEL_CFG_SEL | uint32(config.SDA)<<esp.GPIO_FUNC_IN_SEL_CFG_IN_SEL_Pos)
+	config.SDA.Set(true)
+	config.SDA.pinReg().SetBits(esp.GPIO_PIN_PAD_DRIVER)
+	i2c.Bus.SetCTR_SDA_FORCE_OUT(1)
+
+	config.SCL.configure(PinConfig{Mode: PinOutput}, i2c.funcSCL)
+	inFunc(i2c.funcSCL).Set(esp.GPIO_FUNC_IN_SEL_CFG_SEL | uint32(config.SCL)<<esp.GPIO_FUNC_IN_SEL_CFG_IN_SEL_Pos)
+	config.SCL.Set(true)
+	// Configure the pad with the given IO mux configuration.
+	config.SCL.pinReg().SetBits(esp.GPIO_PIN_PAD_DRIVER)
+	i2c.Bus.SetCTR_SCL_FORCE_OUT(1)
+}
+
+//go:inline
+func (i2c *I2C) initFrequency(config I2CConfig) {
+
+	clkmDiv := i2cClkSourceFrequency/(config.Frequency*1024) + 1
+	sclkFreq := i2cClkSourceFrequency / clkmDiv
+	halfCycle := sclkFreq / config.Frequency / 2
+	// SCL
+	sclLow := halfCycle
+	sclWaitHigh := uint32(0)
+	if config.Frequency > 50000 {
+		sclWaitHigh = halfCycle / 8 // compensate the time when freq > 50K
+	}
+	sclHigh := halfCycle - sclWaitHigh
+	// SDA
+	sdaHold := halfCycle / 4
+	sda_sample := halfCycle / 2
+	setup := halfCycle
+	hold := halfCycle
+
+	i2c.Bus.SetSCL_LOW_PERIOD(sclLow - 1)
+	i2c.Bus.SetSCL_HIGH_PERIOD(sclHigh)
+	i2c.Bus.SetSCL_HIGH_PERIOD_SCL_WAIT_HIGH_PERIOD(25)
+	i2c.Bus.SetSCL_RSTART_SETUP_TIME(setup)
+	i2c.Bus.SetSCL_STOP_SETUP_TIME(setup)
+	i2c.Bus.SetSCL_START_HOLD_TIME(hold - 1)
+	i2c.Bus.SetSCL_STOP_HOLD_TIME(hold - 1)
+	i2c.Bus.SetSDA_SAMPLE_TIME(sda_sample)
+	i2c.Bus.SetSDA_HOLD_TIME(sdaHold)
+}
+
+//go:inline
+func (i2c *I2C) startMaster() {
+	// FIFO mode for data
+	i2c.Bus.SetFIFO_CONF_NONFIFO_EN(0)
+	// Reset TX & RX buffers
+	i2c.Bus.SetFIFO_CONF_RX_FIFO_RST(1)
+	i2c.Bus.SetFIFO_CONF_RX_FIFO_RST(0)
+	i2c.Bus.SetFIFO_CONF_TX_FIFO_RST(1)
+	i2c.Bus.SetFIFO_CONF_TX_FIFO_RST(0)
+	// set timeout value
+	i2c.Bus.TO.Set(0x10)
+	// enable master mode
+	i2c.Bus.CTR.Set(0x113)
+	i2c.Bus.SetCTR_CONF_UPGATE(1)
+	i2c.resetMaster()
+}
+
+//go:inline
+func (i2c *I2C) resetMaster() {
+	// reset FSM
+	i2c.Bus.SetCTR_FSM_RST(1)
+	// clear the bus
+	i2c.Bus.SetSCL_SP_CONF_SCL_RST_SLV_NUM(9)
+	i2c.Bus.SetSCL_SP_CONF_SCL_RST_SLV_EN(1)
+	i2c.Bus.SetSCL_STRETCH_CONF_SLAVE_SCL_STRETCH_EN(1)
+	i2c.Bus.SetCTR_CONF_UPGATE(1)
+	i2c.Bus.FILTER_CFG.Set(0x377)
+	// wait for SCL_RST_SLV_EN
+	for i2c.Bus.GetSCL_SP_CONF_SCL_RST_SLV_EN() != 0 {
+	}
+	i2c.Bus.SetSCL_SP_CONF_SCL_RST_SLV_NUM(0)
+}
+
+type i2cCommandType = uint32
+type i2cAck = uint32
+
+const (
+	i2cCMD_RSTART   i2cCommandType = 6 << 11
+	i2cCMD_WRITE    i2cCommandType = 1<<11 | 1<<8 // WRITE + ack_check_en
+	i2cCMD_READ     i2cCommandType = 3<<11 | 1<<8 // READ + ack_check_en
+	i2cCMD_READLAST i2cCommandType = 3<<11 | 5<<8 // READ + ack_check_en + NACK
+	i2cCMD_STOP     i2cCommandType = 2 << 11
+	i2cCMD_END      i2cCommandType = 4 << 11
+)
+
+type i2cCommand struct {
+	cmd  i2cCommandType
+	data []byte
+	head int
+}
+
+//go:linkname nanotime runtime.nanotime
+func nanotime() int64
+
+func (i2c *I2C) transmit(addr uint16, cmd []i2cCommand, timeoutMS int) error {
+	const intMask = esp.I2C_INT_STATUS_END_DETECT_INT_ST_Msk | esp.I2C_INT_STATUS_TRANS_COMPLETE_INT_ST_Msk | esp.I2C_INT_STATUS_TIME_OUT_INT_ST_Msk | esp.I2C_INT_STATUS_NACK_INT_ST_Msk
+	i2c.Bus.INT_CLR.SetBits(intMask)
+	i2c.Bus.INT_ENA.SetBits(intMask)
+	i2c.Bus.SetCTR_CONF_UPGATE(1)
+
+	defer func() {
+		i2c.Bus.INT_CLR.SetBits(intMask)
+		i2c.Bus.INT_ENA.ClearBits(intMask)
+	}()
+
+	timeoutNS := int64(timeoutMS) * 1000000
+	needAddress := true
+	needRestart := false
+	readLast := false
+	var readTo []byte
+	for cmdIdx, reg := 0, &i2c.Bus.COMD0; cmdIdx < len(cmd); {
+		c := &cmd[cmdIdx]
+
+		switch c.cmd {
+		case i2cCMD_RSTART:
+			reg.Set(i2cCMD_RSTART)
+			reg = nextAddress(reg)
+			cmdIdx++
+
+		case i2cCMD_WRITE:
+			count := 32
+			if needAddress {
+				needAddress = false
+				i2c.Bus.SetDATA_FIFO_RDATA((uint32(addr) & 0x7f) << 1)
+				count--
+				i2c.Bus.SLAVE_ADDR.Set(uint32(addr))
+				i2c.Bus.SetCTR_CONF_UPGATE(1)
+			}
+			for ; count > 0 && c.head < len(c.data); count, c.head = count-1, c.head+1 {
+				i2c.Bus.SetDATA_FIFO_RDATA(uint32(c.data[c.head]))
+			}
+			reg.Set(i2cCMD_WRITE | uint32(32-count))
+			reg = nextAddress(reg)
+
+			if c.head < len(c.data) {
+				reg.Set(i2cCMD_END)
+				reg = nil
+			} else {
+				cmdIdx++
+			}
+			needRestart = true
+
+		case i2cCMD_READ:
+			if needAddress {
+				needAddress = false
+				i2c.Bus.SetDATA_FIFO_RDATA((uint32(addr)&0x7f)<<1 | 1)
+				i2c.Bus.SLAVE_ADDR.Set(uint32(addr))
+				reg.Set(i2cCMD_WRITE | 1)
+				reg = nextAddress(reg)
+			}
+			if needRestart {
+				// We need to send RESTART again after i2cCMD_WRITE.
+				reg.Set(i2cCMD_RSTART)
+
+				reg = nextAddress(reg)
+				reg.Set(i2cCMD_WRITE | 1)
+
+				reg = nextAddress(reg)
+				i2c.Bus.SetDATA_FIFO_RDATA((uint32(addr)&0x7f)<<1 | 1)
+				needRestart = false
+			}
+			count := 32
+			bytes := len(c.data) - c.head
+			// Only last byte in sequence must be sent with ACK set to 1 to indicate end of data.
+			split := bytes <= count
+			if split {
+				bytes--
+			}
+			if bytes > 32 {
+				bytes = 32
+			}
+			if bytes > 0 {
+				reg.Set(i2cCMD_READ | uint32(bytes))
+				reg = nextAddress(reg)
+			}
+			if split {
+				readLast = true
+				reg.Set(i2cCMD_READLAST | 1)
+				reg = nextAddress(reg)
+				readTo = c.data[c.head : c.head+bytes+1] // read bytes + 1 last byte
+				cmdIdx++
+			} else {
+				reg.Set(i2cCMD_END)
+				readTo = c.data[c.head : c.head+bytes]
+				reg = nil
+			}
+
+		case i2cCMD_STOP:
+			reg.Set(i2cCMD_STOP)
+			reg = nil
+			cmdIdx++
+		}
+		if reg == nil {
+			// transmit now
+			i2c.Bus.SetCTR_CONF_UPGATE(1)
+			i2c.Bus.SetCTR_TRANS_START(1)
+			end := nanotime() + timeoutNS
+			var mask uint32
+			for mask = i2c.Bus.INT_STATUS.Get(); mask&intMask == 0; mask = i2c.Bus.INT_STATUS.Get() {
+				if nanotime() > end {
+					if readTo != nil {
+						return errI2CReadTimeout
+					}
+					return errI2CWriteTimeout
+				}
+			}
+			switch {
+			case mask&esp.I2C_INT_STATUS_NACK_INT_ST_Msk != 0 && !readLast:
+				return errI2CAckExpected
+			case mask&esp.I2C_INT_STATUS_TIME_OUT_INT_ST_Msk != 0:
+				if readTo != nil {
+					return errI2CReadTimeout
+				}
+				return errI2CWriteTimeout
+			}
+			i2c.Bus.INT_CLR.SetBits(intMask)
+			for i := 0; i < len(readTo); i++ {
+				readTo[i] = byte(i2c.Bus.GetDATA_FIFO_RDATA() & 0xff)
+				c.head++
+			}
+			readTo = nil
+			reg = &i2c.Bus.COMD0
+		}
+	}
+	return nil
+}
+
+// Tx does a single I2C transaction at the specified address.
+// It clocks out the given address, writes the bytes in w, reads back len(r)
+// bytes and stores them in r, and generates a stop condition on the bus.
+func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) {
+	// timeout in milliseconds.
+	const timeout = 40 // 40ms is a reasonable time for a real-time system.
+
+	cmd := i2c.txCmdBuf[:0]
+	cmd = append(cmd, i2cCommand{cmd: i2cCMD_RSTART})
+	if len(w) > 0 {
+		cmd = append(cmd, i2cCommand{cmd: i2cCMD_WRITE, data: w})
+	}
+	if len(r) > 0 {
+		cmd = append(cmd, i2cCommand{cmd: i2cCMD_READ, data: r})
+	}
+	cmd = append(cmd, i2cCommand{cmd: i2cCMD_STOP})
+
+	return i2c.transmit(addr, cmd, timeout)
+}
+
+func (i2c *I2C) SetBaudRate(br uint32) error {
+	return nil
+}
+
+func nextAddress(reg *volatile.Register32) *volatile.Register32 {
+	return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(reg), 4))
+}

src/machine/machine_esp32xx_pwm.go

@@ -0,0 +1,179 @@
+//go:build esp32c3 || esp32s3
+
+// PWM on ESP32-C3/S3 uses the LEDC (LED Control) peripheral, low-speed mode only.
+// One timer drives multiple channels; each channel has its own duty, shared frequency.
+// Pin routing is via GPIO matrix (SigOutBase + channel index).
+//
+// Channel config (chanOp) follows the hardware contract from:
+//   - ESP-IDF: https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/ledc.html
+//     (timer config → channel config → duty + update_duty).
+//   - SVD (e.g. lib/cmsis-svd/data/Espressif/esp32s3.svd): CONF0.PARA_UP "updates
+//     HPOINT, DUTY_START, SIG_OUT_EN, TIMER_SEL, DUTY_NUM, DUTY_CYCLE, DUTY_SCALE,
+//     DUTY_INC for channel and is auto-cleared by hardware"; CONF1.DUTY_START "other
+//     CONF1 fields take effect when this bit is set to 1".
+
+package machine
+
+import (
+	"device/esp"
+	"errors"
+)
+
+const ledcApbClock = 80_000000
+
+const ledcDutyFracBits = 4 // DUTY register has 4 fractional bits; write value<<4
+
+const ledcDividerFracBits = 8 // Clock divider register = actual_divider * 256
+
+var errPWMNoChannel = errors.New("pwm: no free channel")
+
+type LEDCPWM struct {
+	SigOutBase  uint32 // GPIO matrix signal index for channel 0 (e.g. 73 on S3, 45 on C3)
+	NumChannels uint8
+	timerNum    uint8 // 0–3: which LEDC timer (frequency) this PWM uses
+	dutyRes     uint8
+	configured  bool
+	channelPin  [8]Pin
+}
+
+type ledcChanOp uint8
+
+const (
+	ledcChanOpInit      ledcChanOp = iota // initial per-channel setup (timer, enable, HPOINT/DUTY/CONF1, PARA_UP)
+	ledcChanOpSetDuty                     // update duty and latch it (DUTY + CONF1 + PARA_UP)
+	ledcChanOpSetInvert                   // change idle level (IDLE_LV)
+)
+
+func (pwm *LEDCPWM) Configure(config PWMConfig) error {
+	// Enable LEDC clock and release reset (SYSTEM perip_clk_en0 / perip_rst_en0).
+	esp.SYSTEM.SetPERIP_RST_EN0_LEDC_RST(1)
+	esp.SYSTEM.SetPERIP_CLK_EN0_LEDC_CLK_EN(1)
+	esp.SYSTEM.SetPERIP_RST_EN0_LEDC_RST(0)
+
+	// LEDC global: APB clock source, enable internal clock.
+	esp.LEDC.SetCONF_APB_CLK_SEL(1)
+	esp.LEDC.SetCONF_CLK_EN(1)
+
+	period := config.Period
+	if period == 0 {
+		period = 1_000_000
+	}
+	freq := uint64(1e9) / period
+	dutyRes := uint8(10)
+	switch {
+	case freq < 100:
+		dutyRes = 14
+	case freq < 1000:
+		dutyRes = 12
+	case freq > 100_000:
+		dutyRes = 8
+	}
+
+	// Timer divider: period_ns = (2^dutyRes * divActual/256) / 80MHz * 1e9 => divReg = divActual<<8.
+	divActual := ledcApbClock / (uint32(freq) * (1 << dutyRes))
+	if divActual == 0 {
+		divActual = 1
+	}
+	divReg := divActual << ledcDividerFracBits
+	if divReg > 0x3ffff {
+		return ErrPWMPeriodTooLong
+	}
+
+	// Selected timer: resolution, divider, no pause, reset then latch config with PARA_UP.
+	pwm.setTimerConf(dutyRes, divReg)
+
+	pwm.dutyRes = dutyRes
+	pwm.configured = true
+	for i := range pwm.channelPin {
+		pwm.channelPin[i] = NoPin
+	}
+	return nil
+}
+
+func (pwm *LEDCPWM) setTimerConf(dutyRes uint8, divReg uint32) {
+	t := pwm.timerNum
+	switch t {
+	case 0:
+		esp.LEDC.SetTIMER0_CONF_DUTY_RES(uint32(dutyRes))
+		esp.LEDC.SetTIMER0_CONF_CLK_DIV(divReg)
+		esp.LEDC.SetTIMER0_CONF_TICK_SEL(0)
+		esp.LEDC.SetTIMER0_CONF_PAUSE(0)
+		esp.LEDC.SetTIMER0_CONF_RST(1)
+		esp.LEDC.SetTIMER0_CONF_RST(0)
+		esp.LEDC.SetTIMER0_CONF_PARA_UP(1)
+	case 1:
+		esp.LEDC.SetTIMER1_CONF_DUTY_RES(uint32(dutyRes))
+		esp.LEDC.SetTIMER1_CONF_CLK_DIV(divReg)
+		esp.LEDC.SetTIMER1_CONF_TICK_SEL(0)
+		esp.LEDC.SetTIMER1_CONF_PAUSE(0)
+		esp.LEDC.SetTIMER1_CONF_RST(1)
+		esp.LEDC.SetTIMER1_CONF_RST(0)
+		esp.LEDC.SetTIMER1_CONF_PARA_UP(1)
+	case 2:
+		esp.LEDC.SetTIMER2_CONF_DUTY_RES(uint32(dutyRes))
+		esp.LEDC.SetTIMER2_CONF_CLK_DIV(divReg)
+		esp.LEDC.SetTIMER2_CONF_TICK_SEL(0)
+		esp.LEDC.SetTIMER2_CONF_PAUSE(0)
+		esp.LEDC.SetTIMER2_CONF_RST(1)
+		esp.LEDC.SetTIMER2_CONF_RST(0)
+		esp.LEDC.SetTIMER2_CONF_PARA_UP(1)
+	case 3:
+		esp.LEDC.SetTIMER3_CONF_DUTY_RES(uint32(dutyRes))
+		esp.LEDC.SetTIMER3_CONF_CLK_DIV(divReg)
+		esp.LEDC.SetTIMER3_CONF_TICK_SEL(0)
+		esp.LEDC.SetTIMER3_CONF_PAUSE(0)
+		esp.LEDC.SetTIMER3_CONF_RST(1)
+		esp.LEDC.SetTIMER3_CONF_RST(0)
+		esp.LEDC.SetTIMER3_CONF_PARA_UP(1)
+	}
+}
+
+func (pwm *LEDCPWM) Channel(pin Pin) (uint8, error) {
+	if !pwm.configured {
+		return 0, errors.New("pwm: not configured")
+	}
+	if pin == NoPin {
+		return 0, ErrInvalidOutputPin
+	}
+	var ch uint8
+	for ch = 0; ch < pwm.NumChannels; ch++ {
+		if pwm.channelPin[ch] == NoPin {
+			break
+		}
+	}
+	if ch >= pwm.NumChannels {
+		return 0, errPWMNoChannel
+	}
+
+	pwm.channelPin[ch] = pin
+	signal := pwm.SigOutBase + uint32(ch)
+	pin.configure(PinConfig{Mode: PinOutput}, signal) // GPIO matrix: pin <- LEDC_LS_SIG_OUTn
+	pwm.chanOp(ch, ledcChanOpInit, 0, false)
+	return ch, nil
+}
+
+func (pwm *LEDCPWM) Set(channel uint8, value uint32) {
+	if channel >= pwm.NumChannels {
+		return
+	}
+	top := uint32(1<<pwm.dutyRes) - 1
+	if value > top {
+		value = top
+	}
+	dutyVal := value << ledcDutyFracBits
+	pwm.chanOp(channel, ledcChanOpSetDuty, dutyVal, false)
+}
+
+func (pwm *LEDCPWM) Top() uint32 {
+	if !pwm.configured {
+		return 0
+	}
+	return uint32(1<<pwm.dutyRes) - 1
+}
+
+func (pwm *LEDCPWM) SetInverting(channel uint8, inverting bool) {
+	if channel >= pwm.NumChannels {
+		return
+	}
+	pwm.chanOp(channel, ledcChanOpSetInvert, 0, inverting)
+}

src/machine/machine_esp32xx_simulator.go

@@ -0,0 +1,134 @@
+//go:build !baremetal && (xiao_esp32c3 || xiao_esp32s3)
+
+// Simulator support for ESP32-C3 and ESP32-S3 based boards.
+
+package machine
+
+// Hardware pin numbers
+const (
+	GPIO0  Pin = 0
+	GPIO1  Pin = 1
+	GPIO2  Pin = 2
+	GPIO3  Pin = 3
+	GPIO4  Pin = 4
+	GPIO5  Pin = 5
+	GPIO6  Pin = 6
+	GPIO7  Pin = 7
+	GPIO8  Pin = 8
+	GPIO9  Pin = 9
+	GPIO10 Pin = 10
+	GPIO11 Pin = 11
+	GPIO12 Pin = 12
+	GPIO13 Pin = 13
+	GPIO14 Pin = 14
+	GPIO15 Pin = 15
+	GPIO16 Pin = 16
+	GPIO17 Pin = 17
+	GPIO18 Pin = 18
+	GPIO19 Pin = 19
+	GPIO20 Pin = 20
+	GPIO21 Pin = 21
+	GPIO26 Pin = 26
+	GPIO27 Pin = 27
+	GPIO28 Pin = 28
+	GPIO29 Pin = 29
+	GPIO30 Pin = 30
+	GPIO31 Pin = 31
+	GPIO32 Pin = 32
+	GPIO33 Pin = 33
+	GPIO34 Pin = 34
+	GPIO35 Pin = 35
+	GPIO36 Pin = 36
+	GPIO37 Pin = 37
+	GPIO38 Pin = 38
+	GPIO39 Pin = 39
+	GPIO40 Pin = 40
+	GPIO41 Pin = 41
+	GPIO42 Pin = 42
+	GPIO43 Pin = 43
+	GPIO44 Pin = 44
+	GPIO45 Pin = 45
+	GPIO46 Pin = 46
+	GPIO47 Pin = 47
+	GPIO48 Pin = 48
+)
+
+const (
+	ADC0  Pin = GPIO1
+	ADC2  Pin = GPIO2
+	ADC3  Pin = GPIO3
+	ADC4  Pin = GPIO4
+	ADC5  Pin = GPIO5
+	ADC6  Pin = GPIO6
+	ADC7  Pin = GPIO7
+	ADC8  Pin = GPIO8
+	ADC9  Pin = GPIO9
+	ADC10 Pin = GPIO10
+	ADC11 Pin = GPIO11
+	ADC12 Pin = GPIO12
+	ADC13 Pin = GPIO13
+	ADC14 Pin = GPIO14
+	ADC15 Pin = GPIO15
+	ADC16 Pin = GPIO16
+	ADC17 Pin = GPIO17
+	ADC18 Pin = GPIO18
+	ADC19 Pin = GPIO19
+	ADC20 Pin = GPIO20
+)
+
+// Channel values below are nil, so that they get filled in on the first use.
+// This is the same as what happens on baremetal.
+
+var PWM0 = &timerType{
+	instance:   0,
+	frequency:  16e6,
+	bits:       15,
+	prescalers: []int{1, 2, 4, 8, 16, 32, 64, 128},
+	channelPins: [][]Pin{
+		nil, // channel 0
+		nil, // channel 1
+		nil, // channel 2
+		nil, // channel 3
+	},
+}
+
+var PWM1 = &timerType{
+	instance:   1,
+	frequency:  16e6,
+	bits:       15,
+	prescalers: []int{1, 2, 4, 8, 16, 32, 64, 128},
+	channelPins: [][]Pin{
+		nil, // channel 0
+		nil, // channel 1
+		nil, // channel 2
+		nil, // channel 3
+	},
+}
+
+var PWM2 = &timerType{
+	instance:   2,
+	frequency:  16e6,
+	bits:       15,
+	prescalers: []int{1, 2, 4, 8, 16, 32, 64, 128},
+	channelPins: [][]Pin{
+		nil, // channel 0
+		nil, // channel 1
+		nil, // channel 2
+		nil, // channel 3
+	},
+}
+
+var PWM3 = &timerType{
+	instance:   3,
+	frequency:  16e6,
+	bits:       15,
+	prescalers: []int{1, 2, 4, 8, 16, 32, 64, 128},
+	channelPins: [][]Pin{
+		nil, // channel 0
+		nil, // channel 1
+		nil, // channel 2
+		nil, // channel 3
+	},
+}
+
+var I2C0 = &I2C{Bus: 0}

src/machine/machine_esp32xx_spi.go

@@ -0,0 +1,101 @@
+//go:build esp32s3 || esp32c3
+
+package machine
+
+import (
+	"runtime/volatile"
+)
+
+// SPIConfig is used to store config info for SPI.
+type SPIConfig struct {
+	Frequency uint32
+	SCK       Pin   // Serial Clock
+	SDO       Pin   // Serial Data Out (MOSI)
+	SDI       Pin   // Serial Data In  (MISO)
+	CS        Pin   // Chip Select (optional)
+	LSBFirst  bool  // MSB is default
+	Mode      uint8 // Mode0 is default
+}
+
+// freqToClockDiv computes the SPI bus clock divider register value.
+// SPI peripherals on ESP32-C3 and ESP32-S3 are clocked from the APB bus
+// (pplClockFreq, 80 MHz on both chips).
+func freqToClockDiv(hz uint32) uint32 {
+	if hz >= pplClockFreq { // maximum frequency
+		return 1 << 31
+	}
+	if hz < (pplClockFreq / (16 * 64)) { // minimum frequency
+		return 15<<18 | 63<<12 | 31<<6 | 63 // pre=15, n=63
+	}
+
+	// Iterate all 16 prescaler options looking for an exact match
+	// or the smallest error.
+	var bestPre, bestN, bestErr uint32
+	bestN = 1
+	bestErr = 0xffffffff
+	q := uint32(float32(pplClockFreq)/float32(hz) + float32(0.5))
+	for p := uint32(0); p < 16; p++ {
+		n := q/(p+1) - 1
+		if n < 1 { // prescaler became too large, stop enum
+			break
+		}
+		if n > 63 { // prescaler too small, skip to next
+			continue
+		}
+
+		freq := pplClockFreq / ((p + 1) * (n + 1))
+		if freq == hz { // exact match
+			return p<<18 | n<<12 | (n/2)<<6 | n
+		}
+
+		var err uint32
+		if freq < hz {
+			err = hz - freq
+		} else {
+			err = freq - hz
+		}
+		if err < bestErr {
+			bestErr = err
+			bestPre = p
+			bestN = n
+		}
+	}
+
+	return bestPre<<18 | bestN<<12 | (bestN/2)<<6 | bestN
+}
+
+// spiTxFillBuffer writes data from w into the 16-word (64-byte) SPI
+// hardware transfer buffer. Unused words are zeroed so that no stale
+// data from a previous transfer is sent when w is shorter than 64 bytes.
+func spiTxFillBuffer(buf *[16]volatile.Register32, w []byte) {
+	if len(w) >= 64 {
+		// We can fill the entire 64-byte transfer buffer with data.
+		// This loop is slightly faster than the loop below.
+		for i := 0; i < 16; i++ {
+			word := uint32(w[i*4]) | uint32(w[i*4+1])<<8 | uint32(w[i*4+2])<<16 | uint32(w[i*4+3])<<24
+			buf[i].Set(word)
+		}
+	} else {
+		// We can't fill the entire transfer buffer, so we need to be a bit
+		// more careful.
+		// Note that parts of the transfer buffer that aren't used still
+		// need to be set to zero, otherwise we might be transferring
+		// garbage from a previous transmission if w is smaller than r.
+		for i := 0; i < 16; i++ {
+			var word uint32
+			if i*4+3 < len(w) {
+				word |= uint32(w[i*4+3]) << 24
+			}
+			if i*4+2 < len(w) {
+				word |= uint32(w[i*4+2]) << 16
+			}
+			if i*4+1 < len(w) {
+				word |= uint32(w[i*4+1]) << 8
+			}
+			if i*4+0 < len(w) {
+				word |= uint32(w[i*4+0]) << 0
+			}
+			buf[i].Set(word)
+		}
+	}
+}