Building the Linux microPlatform

This is a guide for building the base Linux microPlatform from source for Raspberry Pi 3 (64-bit). Additional information specific to other targets is provided in Additional Linux microPlatform Targets.

This guide assumes the reader is familiar with basic concepts of OpenEmbedded. It is not meant to be an introduction to the OpenEmbedded / Yocto Project. If you’re just getting started, it’s strongly recommended to begin with the documentation provided in References.

Note

Locally built images are useful for local development, testing and for hardware enablement, but are not meant to be updated via OTA. For OTA support we recommend creating your own Factory and using our continuous integration system.

Get Hardware

You will need a x86 computer to develop on; Linux is currently natively supported. On macOS and Windows, see Linux microPlatform Development Container for information on setting up a containerized Linux build environment.

You will also require at least 50GB of storage for a complete Linux microPlatform build.

Set Up Build Environment

On Debian-based Linux distributions, including Ubuntu, run:

$ sudo apt-get install coreutils gawk wget git-core diffstat unzip \
    texinfo g++ gcc-multilib build-essential chrpath socat cpio \
    openjdk-11-jre python2.7 python3 python3-pip python3-pexpect xz-utils \
    debianutils iputils-ping libsdl1.2-dev xterm libssl-dev libelf-dev \
    android-tools-fsutils ca-certificates repo whiptail

Note

If you are running Ubuntu 18.04, make sure to enable the universe repository by adding following line to your /etc/apt/sources.list:

deb http://archive.ubuntu.com/ubuntu/ bionic universe

On other Linux distributions, please check the Yocto Project Quick Start Guide for additional guidance.

Install the Linux microPlatform

The Linux microPlatform sources can be placed in any directory on your workstation, as long it provides enough disk space for the complete build. This uses the Google Repo tool to fetch a variety of Git repositories at known-good revisions, and keep them in sync as time goes on.

  1. Make an installation directory for the Linux microPlatform, and change into its directory:

    mkdir lmp && cd lmp

    (You can also reuse an existing installation directory.)

  2. Install update 71 using repo:

    repo init -u https://github.com/foundriesio/lmp-manifest -b refs/tags/71
repo sync

Set up Work Environment

Next, set up your work environment for building the source.

The supported MACHINE target used by this guide is raspberrypi3-64. (For information on other hardware platforms, see Additional Linux microPlatform Targets.)

The default distribution (DISTRO) is automatically set to lmp, which is provided by the meta-lmp layer (see Linux microPlatform OpenEmbedded / Yocto Layers for more details).

Set up your work environment using the setup-environment script:

MACHINE=raspberrypi3-64 source setup-environment [BUILDDIR]

If MACHINE is not provided, the script will list all possible machines found in every enabled OpenEmbedded / Yocto Project layer, and force one to be selected. BUILDDIR is optional; if it is not specified, the script will default to build-lmp.

Build the lmp-gateway Image

You can build the Linux microPlatform gateway image by running:

bitbake lmp-gateway-image

Note

Depending on the amount of RAM and number of processors and cores in your system, the speed of your Internet connection, and other factors, the first build could take several hours. Subsequent builds run much faster since some artifacts are cached.

At the end of the build, your build artifacts will be found under deploy/images/raspberrypi3-64. The artifact you will use to flash your board is lmp-gateway-image-raspberrypi3-64.wic.gz.

Install the lmp-gateway Image

If you’re using a Raspberry Pi 3, you can use the same procedure outlined for prebuilt binaries in Install Linux microPlatform. See Additional Linux microPlatform Targets for additional information on other targets.

References

The following reference material on OpenEmbedded and Yocto is recommended for those new to either project.