Flashing a target device with the IAR C‐SPY Command Line Utility

Introduction

The IAR C-SPY Command Line Utility (CSpyBat) is commonly used for non-interactive execution of an application from the command line or headless environments such as in continuous integration. Alternatively, CSpyBat can also be used for flashing the target MCU without initiating a debug session.

Description

The IAR C-SPY Command Line utility offers an special option that can be used for flashing the target device without entering a debug session:

Option	Description
--download_only	Downloads a code image without starting a debug session afterwards.

Example

This example applies to the IAR Build Tools for Arm (CX) with a simplified workflow as follows:

1. A build-job runs in the cloud, inside a container, produces an executable for the an an ST STM32F407VG MCU, and uploads the artifact using a GitHub Action.

2. A flash-job runs on a self-hosted with the IAR Build Tools for Arm and utilizes CSpyBat for flashing a target MCU via an IAR I-jet debug probe.

jobs:
  # Things happen...
  build-job:
    runs-on: ubuntu-latest
    container: ghcr.io/iarsystems/arm:9.60.4-st
    steps:
    # Build the application with "iarbuild" or "cmake" and then...
    - name: Upload the executable as an artifact
      uses: action/upload-artifact@v4
      with:
        name: project
        # Needs to be updated with the proper location of the project.out...
        path: path/to/project.out

   # Other things might be happening in between and then...
   flash-job:
      needs: [ build-job ]
      runs-on: [ self-hosted, linux ]
      steps:
      - name: Download the artifact
        uses: actions/download-artifact@v4
        with:
          name: project
          path: ./
      - name: Flash the target MCU
        run: |
          /opt/iar/cxarm/common/bin/CSpyBat \
            /opt/iar/cxarm/arm/bin/libarmPROC.so \
            /opt/iar/cxarm/arm/bin/libarmJET.so \
            --plugin=/opt/iar/cxarm/arm/bin/libarmLibsupportUniversal.so \
            --flash_loader=/opt/iar/cxarm/arm/config/flashloader/ST/FlashSTM32F4xxx.board \
            --debug_file=project.out \
            --download_only \
            --backend \
              --cpu=cortex-m4 \
              --fpu=vfpv4_sp \
              --device=STM32F407VG \
              --jet_power_from_probe=switch_off \
              --drv_interface=SWD

  # There could be additional jobs described after...