Identify the Requirements and Tools
- Determine the version control system you will use (e.g., Git).
- Choose a CI service that supports embedded development, such as Jenkins, Travis CI, or GitLab CI.
- Ensure you have a cross-compiler for your target embedded architecture.
- Decide on a testing framework suitable for embedded systems and hardware interfaces, like Ceedling or Unity.
Set Up Your Version Control
- Ensure your source code is stored in a branch of your version control system, optimizing the branch structure to separate production, development, and feature-in-progress code.
- Configure webhooks or integrations between your version control system and your CI tool to trigger builds automatically upon code changes.
Prepare Your Build Environment
- Install and configure the cross-compiler toolchain on your CI server to compile the embedded firmware for your specific target architecture.
- Create scripts that automate the setting up of build dependencies, compiling the code, and packaging the output. Consider using makefiles or CMake.
Creating the CI Configuration File
- For Jenkins, create a Jenkinsfile; for Travis CI, use a .travis.yml file; and for GitLab CI, create a .gitlab-ci.yml file.
- Define the build stages inside your CI configuration file, which may include stages like "Build," "Test," and "Deploy."
- Use environment variables to pass configuration variables into the CI process easily, ensuring they are securely stored if they contain sensitive information.
Example for Travis CI:
language: c
compiler:
- gcc
before_install:
- sudo apt-get update -q
install:
- sudo apt-get install -y make cmake gcc-arm-none-eabi
script:
- mkdir build
- cd build
- cmake ..
- make
- make test
Implement Automated Testing
- Integrate an embedded-targeted test framework like Ceedling or Unity in your project.
- Write unit tests covering the critical and functional areas of your embedded system, such as device initialization, main task loops, and interrupt handlers.
- Incorporate tests that validate hardware interface interactions using mocks or simulators if real hardware devices cannot be used.
Handling Hardware-in-the-Loop (HIL) Testing
- Set up a test bench where your embedded target hardware can be automatically flashed with firmware built by your CI system.
- Interface your CI system with test equipment or devices for real-time hardware response validation.
- Use scripts to control hardware reset, flashing, and execution, collecting test outputs via serial or network links.
Deploying Artifacts
- Configure your CI system to archive and save build artifacts, like ELF binaries or generated documentation, so they can be easily accessed.
- Integrate deployment steps if automated provisioning is possible, for example, updating a test fleet of devices or deploying firmware to a remote update server.
Monitor and Iterate
- Set up monitoring and notification systems in your CI pipeline to alert when builds fail or pass important thresholds.
- Iterate on your CI pipeline configuration based on build performance metrics and testing coverage reports, improving as you discover flaws or inefficiencies.
