Build and run the Corstone-320 application

Build ExecuTorch for Cortex-M85

You already have the exported model and validation audio. You’ll package both the model and audio into a bare-metal application and run the application on a virtual Cortex-M85 and Ethos-U85 system.

Start by building ExecuTorch for Cortex-M85.

Continue from the ExecuTorch repository root. Activate the environment and build the target libraries:

    

        
        
source .venv/bin/activate
source examples/arm/arm-scratch/setup_path.sh
if [ "$(uname -s)" = Darwin ]; then
  export PATH="$PWD/examples/arm/arm-scratch/FVPs-on-Mac/bin:$PATH"
  export FVP_MOUNT_DIR="$PWD"
fi

cmake --preset arm-baremetal \
  -DCMAKE_BUILD_TYPE=Release \
  -DTARGET_CPU=cortex-m85 \
  -B cmake-out-arm -S .
cmake --build cmake-out-arm --target install --parallel 2

    

The installed libraries provide the ExecuTorch runtime, portable operators, and Ethos-U backend used by the application.

Build the Silero VAD application

Configure the application with the exported model, validation audio, and the default speech threshold of 0.5. The command selects the UART address required by FVPs-on-Mac:

    

        
        
runtime_cmake_args=()
if [ "$(uname -s)" = Darwin ]; then
  runtime_cmake_args+=(-DUART0_BASE=0x49303000)
fi

cmake \
  "${runtime_cmake_args[@]}" \
  -DCMAKE_TOOLCHAIN_FILE="$PWD/examples/arm/ethos-u-setup/arm-none-eabi-gcc.cmake" \
  -DCMAKE_BUILD_TYPE=Release \
  -DTARGET_CPU=cortex-m85 \
  -DET_PTE_FILE_PATH="$PWD/silero_vad_ethos_u.pte" \
  -DAUDIO_PATH="$PWD/silero-vad/validation.wav" \
  -B examples/arm/silero_vad_ethos_u \
  -S examples/arm/silero_vad_example_ethos_u/runtime

    

Build the configured application:

    

        
        
cmake --build examples/arm/silero_vad_ethos_u \
  --target silero_vad_ethos_u --parallel 2

    

The build creates examples/arm/silero_vad_ethos_u/silero_vad_ethos_u. This ELF image contains both the .pte model and the 2.5-second validation clip.

Run Silero VAD on the FVP

Run the application and save its simulated UART output to fvp.log:

    

        
        
set -o pipefail
bash backends/arm/scripts/run_fvp.sh \
  --elf=examples/arm/silero_vad_ethos_u/silero_vad_ethos_u \
  --target=ethos-u85-256 \
  --timeout=300 2>&1 | tee fvp.log

    

The application processes one audio frame every 32 ms of recording time, then prints the probabilities and a summary. The output is similar to:

    

        
        2 segments, 79 frames, 2.5s
Speech: 56/79 frames (70.9%)
Model executed successfully.
Simulation complete, 0
No problems found!

        
    

Check the target artifacts

Confirm that the application and its serial log exist:

    

        
        
for artifact in \
  examples/arm/silero_vad_ethos_u/silero_vad_ethos_u \
  fvp.log; do
  test -s "$artifact" || {
    echo "Missing target artifact: $artifact" >&2
    exit 1
  }
done

echo "Target artifacts verified."

    

What you’ve accomplished and what’s next

You’ve run the stateful Silero VAD model on a virtual Cortex-M85 and Ethos-U85 target.

Next, you’ll inspect the speech decisions and compare them with the host reference.