Add Cortex-M e2e integration tests on trunk

Add a CI job that exports models (mv2, mv3) via aot_arm_compiler.py
with --target=cortex-m55+int8 and runs them on the Corstone-300 FVP.
Uses matrix strategy so adding models is just appending to the list.

- New .ci/scripts/test_cortex_m_e2e.sh: export + FVP runner script
- Enable --bundleio in build_test_runner.sh for .bpte support
- Add test-cortex-m-e2e job to trunk.yml

Authored with Claude.

Author: psiddh

.ci/scripts/test_cortex_m_e2e.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+# End-to-end test for Cortex-M backend: export a model via aot_arm_compiler
+# with cortex-m55+int8 target, then run the .bpte on Corstone-300 FVP.
+#
+# Usage: bash .ci/scripts/test_cortex_m_e2e.sh <model_name>
+# Example: bash .ci/scripts/test_cortex_m_e2e.sh mv2
+
+set -eux
+
+MODEL=$1
+WORK_DIR="./cortex_m_e2e/${MODEL}"
+mkdir -p "${WORK_DIR}"
+
+echo "=== Exporting ${MODEL} with cortex-m55+int8 ==="
+python -m examples.arm.aot_arm_compiler \
+    -m "${MODEL}" \
+    --target=cortex-m55+int8 \
+    --quantize \
+    --bundleio \
+    --intermediates="${WORK_DIR}/intermediates" \
+    --output="${WORK_DIR}/${MODEL}.bpte"
+
+BPTE="${WORK_DIR}/${MODEL}.bpte"
+test -f "${BPTE}" || { echo "FAIL: ${BPTE} not produced"; exit 1; }
+echo "=== Exported ${BPTE} ($(stat --printf='%s' "${BPTE}") bytes) ==="
+
+ELF="arm_test/arm_semihosting_executor_runner_corstone-300/arm_executor_runner"
+test -f "${ELF}" || { echo "FAIL: executor runner not found at ${ELF}"; exit 1; }
+
+# Copy .bpte into work dir so FVP semihosting can find it via cwd
+cp "${BPTE}" "${WORK_DIR}/${MODEL}.bpte"
+
+echo "=== Running ${MODEL} on Corstone-300 FVP ==="
+FVP_Corstone_SSE-300_Ethos-U55 \
+    -C ethosu.num_macs=128 \
+    -C mps3_board.visualisation.disable-visualisation=1 \
+    -C cpu0.semihosting-enable=1 \
+    -C "cpu0.semihosting-cwd=${WORK_DIR}" \
+    -C "ethosu.extra_args='--fast'" \
+    -C "cpu0.semihosting-cmd_line='executor_runner -m ${MODEL}.bpte'" \
+    -a "${ELF}" \
+    --timelimit 300
+
+echo "=== SUCCESS: ${MODEL} e2e passed on FVP ==="

.github/workflows/trunk.yml

@@ -1084,3 +1084,37 @@ jobs:
 
         # To run cortex_m tests
         pytest --config-file=backends/arm/test/pytest.ini backends/cortex_m/test
+
+  test-cortex-m-e2e:
+    name: test-cortex-m-e2e
+    uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main
+    strategy:
+      matrix:
+        model: [mv2, mv3]
+      fail-fast: false
+    permissions:
+      id-token: write
+      contents: read
+    with:
+      runner: linux.2xlarge.memory
+      docker-image: ci-image:executorch-ubuntu-22.04-arm-sdk
+      submodules: 'recursive'
+      ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
+      timeout: 120
+      script: |
+        # The generic Linux job chooses to use base env, not the one setup by the image
+        CONDA_ENV=$(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 dependencies
+        .ci/scripts/setup-arm-baremetal-tools.sh
+        source examples/arm/arm-scratch/setup_path.sh
+
+        # Build cortex-m test runner with bundled IO support
+        backends/cortex_m/test/build_test_runner.sh
+
+        # Export model and run on FVP
+        bash .ci/scripts/test_cortex_m_e2e.sh ${{ matrix.model }}

backends/cortex_m/test/build_test_runner.sh

@@ -31,4 +31,4 @@ aten::unsqueeze_copy.out,\
 aten::select_copy.int_out,\
 aten::amax.out"
 
-${build_executor_runner} --pte=semihosting --target=ethos-u55-128 --output="${build_root_test_dir}" --select_ops_list="${select_ops_list}"
+${build_executor_runner} --pte=semihosting --bundleio --target=ethos-u55-128 --output="${build_root_test_dir}" --select_ops_list="${select_ops_list}"