What is rpi-image-gen?

rpi-image-gen is a lightweight, scriptable framework for generating Raspberry Pi OS–based images. It takes a base root filesystem (Raspberry Pi OS Lite or Full) and applies layered customizations to produce a ready-to-flash .img file.

In essence, it’s a reproducible dd workflow — automated, version-controlled, and highly configurable.

Why use it?

Unlike Yocto or Buildroot, rpi-image-gen doesn’t rebuild packages from source. Instead, it leverages Debian’s binary packages and the existing Raspberry Pi infrastructure. This allows you to:

  • Add configuration files, services, and users
  • Enable or disable systemd units
  • Preinstall applications and dependencies
  • Embed SSH keys, Wi-Fi credentials, and device IDs

It’s the fastest way to go from prototype to production, while keeping full control over your system setup.

Core concepts

A typical rpi-image-gen project consists of the following components:

  • Base image — the official Raspberry Pi OS Lite
  • Overlay directory — your additional files, services, and scripts
  • Customization hooks — pre- and post-filesystem injection scripts
  • Build configuration — defining rootfs, boot partitions, layout, and version tags

rpi-image-gen scheme

Together, these elements produce a consistent, bootable image that’s ready for provisioning.

Installation

Follow the installation instructions at https://github.com/raspberrypi/rpi-image-gen.

Example

A typical project might look like this:

deb12-cm5-min-desktop
├── README.md
├── config
│   └── deb12-cm5-min-desktop.yaml
├── device
│   ├── cm5-device.yaml
│   └── rootfs-overlay
│       ├── etc
│       │   ├── lightdm
│       │   └── skel
│       └── usr
│           └── local
└── layer
    ├── image
    │   └── simple-dual-nosparse
    │       ├── bdebstrap
    │       ├── device
    │       ├── genimage.cfg.in.btrfs
    │       ├── genimage.cfg.in.ext4
    │       ├── image.yaml
    │       ├── mke2fs.conf
    │       ├── pre-image.sh
    │       └── setup.sh
    └── packages.yaml

The most important files are the YAML configuration files — these define which packages, files, and settings are included in the generated image.

Configuration Example

config/deb12-cm5-min-desktop.yaml — defines global parameters such as hostname, user credentials, partition sizes, and SSH keys:

device:
  layer: cm5-device
  hostname: cm5-dev
  user1: pi
  user1pass: StrongPass!1

image:
  layer: image-rpios-nosparse
  rootfs_type: ext4
  boot_part_size: 512M
  root_part_size: 4G
  compression: zstd
  name: deb12-cm5-min-desktop

layer:
  custom: base-packages

ssh:
  pubkey_user1: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAB"   # your custom public key
  pubkey_only: y

layer/packages.yaml — lists the software packages, configuration files, and custom additions, such as a Qt application:

# METABEGIN
# X-Env-Layer-Name: base-packages
# X-Env-Layer-Desc: Installs base packages
#  for sw development.
# X-Env-Layer-Version: 1.0.0
# X-Env-Layer-Requires: debian-bookworm-arm64-multi,
#  rpi-debian-bookworm,
#  rpi-misc-utils,
#  rpi-essential-base,
#  rpi-misc-skel,
#  rpi-user-credentials,
#  systemd-net-min,
#  fake-hwclock,
#  openssh-server
# METAEND
---
mmdebstrap:
  setup-hooks:
    - echo "hello - no setup-hooks in base-packages"
  packages:
    # Firmware to enable SHIFT boot manager and EEPROM maintenance
    - raspberrypi-bootloader
    - rpi-eeprom
    - raspberrypi-ui-mods
    - lightdm
    - lightdm-gtk-greeter
    - labwc
    - wf-panel-pi
    - lxsession
    - lxpanel
    - pcmanfm
    - lxterminal
    - gvfs
    - xserver-xorg
    - xwayland
    - wayland-utils
    - wlr-randr
    - x11-xserver-utils
    - xdg-user-dirs
    - xdg-utils
    - policykit-1
    # helper and utilities
    - bash
    - sudo
    - vim-tiny
    - less
    - nano
    - network-manager
    - bash-completion
    # library manager
    - libinput10
    - libinput-bin
    - libinput-dev
    # sqlite
    - sqlite3
    - libsqlite3-0
    - libsqlite3-dev
  customize-hooks:
    - echo "hello - customize-hooks in base-packages"
    - $BDEBSTRAP_HOOKS/enable-units "$1" lightdm
    - sed "s|alias ls='ls --color=auto'|alias ll='ls -al --color=auto'|" /home/$IGconf_device_user1/.bashrc > $1/home/$IGconf_device_user1/.bashrc
    - uchroot $1 'mkdir -m 0700 -p ${HOME}/.config/labwc'
    - cp "${IGconf_device_assetdir}/rootfs-overlay/etc/skel/.config/labwc/autostart" "$1/home/$IGconf_device_user1/.config/labwc/autostart"
    - cp "${IGconf_device_assetdir}/rootfs-overlay/etc/skel/.config/labwc/environment" "$1/home/$IGconf_device_user1/.config/labwc/environment"
    - cp "${IGconf_device_assetdir}/rootfs-overlay/etc/skel/.config/labwc/rc.xml" "$1/home/$IGconf_device_user1/.config/labwc/rc.xml"
    - chown "${IGconf_device_user1}:${IGconf_device_user1}" "$1/home/$IGconf_device_user1/.config/labwc/autostart"
    - chown "${IGconf_device_user1}:${IGconf_device_user1}" "$1/home/$IGconf_device_user1/.config/labwc/environment"
    - chown "${IGconf_device_user1}:${IGconf_device_user1}" "$1/home/$IGconf_device_user1/.config/labwc/rc.xml"

For a complete working example, see: https://github.com/interelectronix/rpi-image-gen-projects/tree/main/deb12-cm5-min-desktop

Build command

To build the image, run:

rpi-image-gen build -S path-to-project-folder -c deb12-cm5-min-desktop.yaml

CI/CD and reproducibility

Once your build scripts are deterministic, you can integrate rpi-image-gen into a CI/CD pipeline (e.g., GitHub Actions, GitLab CI, Jenkins).

Each build produces a traceable, versioned artifact, enabling reliable updates and easier debugging — a crucial step toward production-grade deployment.

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