Yocto community integration layers for Mender

Mender is an open source over-the-air (OTA) software updater for embedded Linux devices. Mender comprises a client running at the embedded device, as well as a server that manages deployments across many devices.

This repository contains Yocto integration layers for various boards.

Please check out https://hub.mender.io for more information on supported boards and instructions on how to setup environment and build images.

Structure

This section is for anyone interested in contributing support for a board.

meta-mender-community is a repository containing multiple Yocto layers for integrating Mender onto various boards.

The layers are structured based on upstream BSP layers and not individual boards.

There are multiple types of layers included here.

SoC-oriented:

• meta-mender-amlogic
• meta-mender-nxp
• meta-mender-tegra ...

Vendor-oriented:

• meta-mender-raspberrypi
• meta-mender-toradex-nxp
• meta-mender-octavo-osd32mp ...

Naming of integration layers follows the upstream naming conventions with SoM vendor layer name having priority. The convention is:

   meta-mender-<upstream suffix>

This should make it clear which layer is targeting what BSP.

Build setup

Traditionally meta-mender-community has required board integrations to provide build setup configuration through the repo tool by Google. As it has a number of shortcomings, things are being moved to kas.

All submitted board integrations need to provide a build setup strategy. New repo-based setups will usually be rejected.

kas

For an introduction on kas, please see the tutorial article on the Mender Hub.

Building an image for a supported board

Quick start

To build an image using kas, you simply call it with the build verb and the desired configuration. Example for the Raspberry Pi 4, 64bit:

kas build meta-mender-community/kas/raspberrypi4-64.yml

A full getting started build procedure

Install the kas tool (optionally, you can install globally for all users. Run as root, respectively under sudo then):

pip install kas

Clone this repository:

git clone https://github.com/mendersoftware/meta-mender-community

Create a build directory and change into it:

mkdir -p meta-mender-community/my-build && cd meta-mender-community/my-build

Call kas to build for the Raspberry Pi 4, 64bit:

kas build ../kas/raspberrypi4-64.yml

The canonical build structure including resulting deployable images is located under meta-mender-community/my-build/build.

Adding a new build configuration

In the most straightforward case, a board integration can simply consist of a kas configuration file. Those are located in the kas top level directory.

Some relevant best practises:

• if possible, common parts of board integrations should be factored out into includes. Those are located in the kas/include directory.
• the mender-full.yml or mender-full-ubi.yml includes should be used as baseline
• a minimal approach concerning image and DISTRO should be preferred
  • the default image is core-image-minimal, consider keeping it unless your platform has specific requirements
  • the default DISTRO is a nodistro, pure OpenEmbedded setup. While selecting a larger or custom DISTRO is acceptable, consider being as slim as possible to provide the highest degree of freedom to your users.

Requirements:

• revisions of metadata layers defined in the configurations must be fixed. Exception: the master branch which tracks the Yocto Project / OpenEmbedded upstream
• the primary targetted branch must be a Yocto Project LTS correlated one
• add your board to the automated build configuration at .github/workflows/build.yml, marked as experimental. It will be moved out of experimental after a number of successful builds by the Mender team.

Google repo

Note: repo support is currently kept for compatibility reasons but will be removed in the future.

Manifest files

The google repo tool and associated manifest files are used for managing the list of repositories needed for these builds. The common manifests (meta-mender-community/scripts/mender.xml) is included by board-specific manifests and include the required Mender layers:

meta-mender-community/scripts/mender.xml

This includes the required Mender layers, meta-mender and meta-mender-community.

Each integration layer should provide a manifest file, e.g

meta-mender-community/meta-mender-sunxi/scripts/manifest-sunxi.xml

Templates and configuration fragments

To use this layer:

1. Download the source:

    $ mkdir mender-<vendor/soc name>
    $ cd mender-<vendor/soc name>
    $ repo init \
           -u https://github.com/mendersoftware/meta-mender-community \
           -m meta-mender-<vendor/soc name>/scripts/manifest-<vendor/soc name>.xml \
           -b kirkstone
    $ repo sync

2. Setup environment:

    $ . ./setup-environment <vendor/soc name>

3. Build:

    $ bitbake core-image-base

The setup-environment script provided is a wrapper for the Yocto oe-init-build-env script.

Each integration layer must provide:

• local.conf.append: this contains board-specific changes to be appended to the Yocto-generated local.conf file
• bblayers.conf.sample: a template that will be copied to bblayers.conf
• an entry in setup-environment

Contributing

We welcome and ask for your contribution. If you would like to contribute to Mender, please read our guide on how to best get started contributing code or documentation.

Community contributed layers will be co-maintained by the Mender team on a best-effort base. Coordination of reviews and merges happens case by case and based on responsiveness, respectively activity. Reviews and acknowledgements by the original contributors are explicitly not required for further contributions, in order to not block development and maintenance.

License

Mender is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.

Connect with us

• Join the Mender Hub discussion forum
• Follow us on Twitter. Please feel free to tweet us questions.
• Fork us on Github
• Create an issue in the bugtracker
• Email us at [email protected]
• Connect to the #mender IRC channel on Libera

Authors

Mender was created by the team at Northern.tech AS, with many contributions from the community. Thanks everyone!

Mender is sponsored by Northern.tech AS.