This repository contains a minimal Yocto build configuration for Raspberry Pi 4 (64-bit) with:

• SSH enabled
• systemd as init system
• Docker container runtime
• GitHub Actions CI/CD pipeline

• Automates the Yocto build environment setup
• Downloads required Yocto layers (poky, meta-raspberrypi, meta-openembedded)
• Configures the build with systemd and SSH
• Runs the bitbake process to build the image

• Uses GitHub Actions to automatically build the image on every push or PR
• Maximizes build space to accommodate Yocto's requirements
• Installs required dependencies
• Runs the build script
• Uploads the resulting image as an artifact using actions/upload-artifact@v4

• conf/layer.conf: Registers the custom layer with Yocto
• recipes-core/images/minimal-ssh-image.bb: Defines the minimal image with SSH and systemd
• recipes-core/systemd/systemd-networkd-configuration.bb: Provides network configuration
• recipes-core/systemd/files/20-wired.network: Configures the ethernet interface

1. Install dependencies (Ubuntu/Debian):

   sudo apt-get update
   sudo apt-get install -y gawk wget git diffstat unzip texinfo gcc build-essential \
     chrpath socat cpio python3 python3-pip python3-pexpect xz-utils debianutils \
     iputils-ping python3-git python3-jinja2 libegl1-mesa libsdl1.2-dev pylint3 xterm

2. Clone this repository:

   git clone https://github.com/yourusername/yocto-cicd-test.git
   cd yocto-cicd-test

3. Run the build script:

   ./scripts/build.sh

4. Find your image at build/tmp/deploy/images/raspberrypi4-64/minimal-ssh-image-raspberrypi4-64.wic.bz2

The image recipe (minimal-ssh-image.bb) creates a streamlined 64-bit system with:

• OpenSSH server for remote access
• systemd init system
• Docker container runtime and docker-compose
• Network configuration via systemd-networkd
• OPKG package manager
• Raspberry Pi Camera support
• Audio/Voice capabilities
• U-Boot bootloader
• Essential kernel modules

The system is configured with:

• Static IP address (192.168.4.103) through systemd-networkd for Ethernet
• You can directly connect via SSH: ssh [email protected]
• WiFi support with WPA Supplicant pre-configured
• No password is required for SSH (debug-tweaks enabled)

The image comes with WiFi support pre-configured. To connect to your WiFi network:

1. Before building, customize the WiFi credentials in:

   meta-custom/recipes-core/systemd/files/wpa_supplicant-wlan0.conf
   

2. Alternatively, after first boot, edit the WiFi configuration:

   nano /etc/wpa_supplicant/wpa_supplicant-wlan0.conf

   Then restart the WiFi service:

   systemctl restart wpa_supplicant@wlan0

3. Verify connectivity:

   ip a show wlan0
   ping -I wlan0 google.com

┌─────────────────┐     ┌──────────────────┐     ┌───────────────┐
│                 │     │                  │     │               │
│  Yocto Project  │────►│  Build System    │────►│ Custom Layer  │
│                 │     │                  │     │               │
└─────────────────┘     └──────────────────┘     └───────┬───────┘
                                                         │
                                                         ▼
┌─────────────────┐     ┌──────────────────┐     ┌───────────────┐
│                 │     │                  │     │               │
│  CI/CD Pipeline │────►│  GitHub Actions  │────►│ Image Output  │
│                 │     │                  │     │               │
└─────────────────┘     └────────┬─────────┘     └───────▲───────┘
                                 │                       │
                                 ▼                       │
                        ┌──────────────────┐     ┌───────────────┐
                        │                  │     │               │
                        │  Raspberry Pi 4  │     │  Recipe       │
                        │  Image Files     │     │  Components   │
                        └──────────────────┘     └───────────────┘

The Yocto CI/CD for Raspberry Pi 4 system implements a complete pipeline for building customized Linux distributions:

1. Source Layer

   • Poky: Core Yocto Project files providing the build system
   • meta-raspberrypi: BSP layer for Raspberry Pi hardware support
   • meta-openembedded: Additional packages and recipes
   • meta-custom: Project-specific customizations and configurations

2. Build System Layer

   • BitBake: Task executor and scheduler for recipe processing
   • Shared State Cache: Accelerates builds by caching build artifacts
   • Fetch System: Downloads source code from upstream repositories
   • Package Management: Creates OPKG packages for the final system

3. Integration Layer

   • CI/CD Pipeline: Automates build process through GitHub Actions
   • Docker Integration: Provides containerized environment for final system
   • Deployment: Prepares bootable images for Raspberry Pi 4

4. Runtime Layer

   • systemd: Init system for service management
   • SSH: Remote access and administration
   • Docker: Container runtime for application deployment
   • Network Configuration: Ethernet and WiFi connectivity setup

• Edit meta-custom/recipes-core/images/minimal-ssh-image.bb to add more packages
• Copy conf/local.conf.sample to your build directory as local.conf for local builds
• Modify meta-custom/recipes-core/systemd/files/20-wired.network to change network settings

After booting your Raspberry Pi with the built image:

1. Docker is pre-installed and ready to use

2. Check Docker status:

   systemctl status docker

3. Run a test container:

   docker run --rm hello-world

4. Create containers with docker-compose:

   docker-compose up -d

The image comes with support for the Raspberry Pi Camera module:

1. Connect the camera module to the Raspberry Pi CSI connector

2. Use the following commands to test the camera:

   # List available cameras
   libcamera-hello --list-cameras
   
   # Display a preview
   libcamera-hello
   
   # Capture an image
   libcamera-still -o test.jpg
   
   # Record a video (5 seconds)
   libcamera-vid -t 5000 -o test.h264

3. GStreamer is also included for advanced video processing:

   gst-launch-1.0 libcamerasrc ! videoconvert ! jpegenc ! filesink location=test.jpg

The image comes with full audio support for the Raspberry Pi:

1. Testing your audio setup:

   # List audio devices
   aplay -l
   
   # Test audio output
   speaker-test -t wav -c 2
   
   # Play an audio file
   aplay /usr/share/sounds/alsa/Front_Center.wav

2. Recording audio:

   # Record audio for 5 seconds
   arecord -d 5 -f cd test.wav
   
   # Play back the recording
   aplay test.wav

3. Audio configuration:

   # Adjust volume
   alsamixer
   
   # Save volume settings
   alsactl store

4. PulseAudio is also included for advanced audio routing and mixing.

The image comes with OPKG package manager pre-installed:

1. Update package lists:

   opkg update

2. Install a package:

   opkg install <package-name>

3. List installed packages:

   opkg list-installed

4. Search for packages:

   opkg list | grep <search-term>

curl -L https://github.com/docker/compose/releases/download/v2.34.0/docker-compose-linux-armv7 -o /usr/bin/docker-compose chmod +x /usr/bin/docker-compose