Add Pico2 build validation CI (trunk only)

.github/workflows/test-pico2-build.yml

@@ -0,0 +1,161 @@
+name: Pico2 Build Validation
+
+on:
+  push:
+    branches: [main, release/*]
+    paths:
+      - examples/raspberry_pi/pico2/**
+      - backends/cortex_m/**
+  schedule:
+    # Run daily at 3 AM UTC to catch upstream breakages
+    - cron: '0 3 * * *'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: true
+
+jobs:
+  test-pico2-fp32-build:
+    name: test-pico2-fp32-build
+    uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main
+    permissions:
+      id-token: write
+      contents: read
+    with:
+      runner: linux.2xlarge.memory
+      docker-image: ci-image:executorch-ubuntu-22.04-arm-sdk
+      submodules: 'recursive'
+      ref: ${{ github.sha }}
+      timeout: 60
+      script: |
+        # Activate conda environment from the docker image
+        CONDA_ENV=$(conda env list --json | jq -r ".envs | .[-1]")
+        conda activate "${CONDA_ENV}"
+
+        source .ci/scripts/utils.sh
+        install_executorch "--use-pt-pinned-commit"
+
+        # Install ARM baremetal toolchain
+        .ci/scripts/setup-arm-baremetal-tools.sh
+        source examples/arm/arm-scratch/setup_path.sh
+
+        echo "=== Step 1: Export FP32 model ==="
+        cd examples/raspberry_pi/pico2
+        python export_mlp_mnist.py
+        test -f balanced_tiny_mlp_mnist.pte
+        echo "FP32 model exported: $(ls -la balanced_tiny_mlp_mnist.pte)"
+        cd -
+
+        echo "=== Step 2: Build FP32 firmware ==="
+        ./examples/raspberry_pi/pico2/build_firmware_pico.sh --model=balanced_tiny_mlp_mnist.pte
+
+        echo "=== Step 3: Validate FP32 artifacts ==="
+        ELF_FILE=examples/raspberry_pi/pico2/build/executorch_pico.elf
+        UF2_FILE=examples/raspberry_pi/pico2/build/executorch_pico.uf2
+
+        test -f "${ELF_FILE}" || { echo "FAIL: .elf not found"; exit 1; }
+        test -f "${UF2_FILE}" || { echo "FAIL: .uf2 not found"; exit 1; }
+
+        echo "--- Section sizes ---"
+        arm-none-eabi-size -A "${ELF_FILE}"
+
+        echo "--- Section headers ---"
+        arm-none-eabi-objdump -h "${ELF_FILE}"
+
+        echo "--- Key symbols ---"
+        arm-none-eabi-nm --print-size --size-sort --radix=d "${ELF_FILE}" | tail -20
+
+        # Validate binary fits in Pico2 memory:
+        #   .text in flash (4MB = 4194304 bytes)
+        #   .bss + .data in SRAM (520KB = 532480 bytes)
+        TEXT_SIZE=$(arm-none-eabi-size -A "${ELF_FILE}" | awk '/.text/ {print $2}')
+        BSS_SIZE=$(arm-none-eabi-size -A "${ELF_FILE}" | awk '/.bss/ {print $2}')
+        DATA_SIZE=$(arm-none-eabi-size -A "${ELF_FILE}" | awk '/.data/ {print $2}')
+
+        echo "FP32 binary: .text=${TEXT_SIZE} .bss=${BSS_SIZE} .data=${DATA_SIZE}"
+
+        SRAM_USED=$((BSS_SIZE + DATA_SIZE))
+        if [ "${TEXT_SIZE}" -gt 4194304 ]; then
+          echo "FAIL: .text (${TEXT_SIZE}) exceeds 4MB flash"
+          exit 1
+        fi
+        if [ "${SRAM_USED}" -gt 532480 ]; then
+          echo "FAIL: .bss+.data (${SRAM_USED}) exceeds 520KB SRAM"
+          exit 1
+        fi
+        echo "PASS: FP32 firmware fits in Pico2 memory (SRAM: ${SRAM_USED}/532480, Flash: ${TEXT_SIZE}/4194304)"
+
+  test-pico2-cmsis-build:
+    name: test-pico2-cmsis-nn-build
+    uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main
+    permissions:
+      id-token: write
+      contents: read
+    with:
+      runner: linux.2xlarge.memory
+      docker-image: ci-image:executorch-ubuntu-22.04-arm-sdk
+      submodules: 'recursive'
+      ref: ${{ github.sha }}
+      timeout: 60
+      script: |
+        # Activate conda environment from the docker image
+        CONDA_ENV=$(conda env list --json | jq -r ".envs | .[-1]")
+        conda activate "${CONDA_ENV}"
+
+        source .ci/scripts/utils.sh
+        install_executorch "--use-pt-pinned-commit"
+
+        # Install ARM baremetal toolchain
+        .ci/scripts/setup-arm-baremetal-tools.sh
+        source examples/arm/arm-scratch/setup_path.sh
+
+        echo "=== Step 1: Export INT8 CMSIS-NN model ==="
+        cd examples/raspberry_pi/pico2
+        python export_mlp_mnist_cmsis.py
+        test -f balanced_tiny_mlp_mnist_cmsis.pte
+        echo "INT8 model exported: $(ls -la balanced_tiny_mlp_mnist_cmsis.pte)"
+        cd -
+
+        echo "=== Step 2: Build CMSIS-NN firmware ==="
+        ./examples/raspberry_pi/pico2/build_firmware_pico.sh --cmsis --model=balanced_tiny_mlp_mnist_cmsis.pte
+
+        echo "=== Step 3: Validate CMSIS-NN artifacts ==="
+        ELF_FILE=examples/raspberry_pi/pico2/build/executorch_pico.elf
+        UF2_FILE=examples/raspberry_pi/pico2/build/executorch_pico.uf2
+
+        test -f "${ELF_FILE}" || { echo "FAIL: .elf not found"; exit 1; }
+        test -f "${UF2_FILE}" || { echo "FAIL: .uf2 not found"; exit 1; }
+
+        echo "--- Section sizes ---"
+        arm-none-eabi-size -A "${ELF_FILE}"
+
+        echo "--- Section headers ---"
+        arm-none-eabi-objdump -h "${ELF_FILE}"
+
+        echo "--- Key symbols ---"
+        arm-none-eabi-nm --print-size --size-sort --radix=d "${ELF_FILE}" | tail -20
+
+        # Verify CMSIS-NN symbols are linked
+        if arm-none-eabi-nm "${ELF_FILE}" | grep -q "cmsis_nn\|arm_nn"; then
+          echo "PASS: CMSIS-NN symbols found in binary"
+        else
+          echo "WARNING: No CMSIS-NN symbols detected — verify cortex_m backend linked correctly"
+        fi
+
+        # Validate binary fits in Pico2 memory
+        TEXT_SIZE=$(arm-none-eabi-size -A "${ELF_FILE}" | awk '/.text/ {print $2}')
+        BSS_SIZE=$(arm-none-eabi-size -A "${ELF_FILE}" | awk '/.bss/ {print $2}')
+        DATA_SIZE=$(arm-none-eabi-size -A "${ELF_FILE}" | awk '/.data/ {print $2}')
+
+        echo "CMSIS-NN binary: .text=${TEXT_SIZE} .bss=${BSS_SIZE} .data=${DATA_SIZE}"
+
+        SRAM_USED=$((BSS_SIZE + DATA_SIZE))
+        if [ "${TEXT_SIZE}" -gt 4194304 ]; then
+          echo "FAIL: .text (${TEXT_SIZE}) exceeds 4MB flash"
+          exit 1
+        fi
+        if [ "${SRAM_USED}" -gt 532480 ]; then
+          echo "FAIL: .bss+.data (${SRAM_USED}) exceeds 520KB SRAM"
+          exit 1
+        fi
+        echo "PASS: CMSIS-NN firmware fits in Pico2 memory (SRAM: ${SRAM_USED}/532480, Flash: ${TEXT_SIZE}/4194304)"