Building From Source

This is a guide for building the base Linux® microPlatform (LmP) from source for QEMU AARCH64 (Arm® 64). Information specific to other targets is provided in Board Machine Names.

This guide assumes familiarity with Open Embedded concepts. If you are just getting started with OpenEmbedded/the Yocto Project, it is strongly recommended to begin with the documentation provided under Build and Install the LmP for your Factory.

Important

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

Hardware Requirements

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

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

Setup the Build Environment

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

$ sudo apt install coreutils gawk wget git 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-sdk-libsparse-utils ca-certificates repo whiptail

Note

If you are running Ubuntu, make sure to enable the universe repository:

sudo add-apt-repository universe

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

Install the LmP

Download the Layers

The LmP sources can be placed in any directory on your workstation, as long it provides enough disk space for the complete build. The Google Repo tool is used to fetch Git repos at known-good revisions, and keeps them in sync.

  1. Make and enter an installation directory for the LmP:

    mkdir lmp && cd lmp

    Note

    You can also reuse an existing installation directory, or /build/lmp if building inside the lmp-sdk container, as described at Development Container.

  2. Install update 94 using Repo:

    repo init -u https://github.com/foundriesio/lmp-manifest -b refs/tags/94
repo sync

Setup Work Environment

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

The supported MACHINE target used by this guide is qemuarm64-secureboot. For information on other hardware platforms, see:ref:ref-linux-supported.

The default distribution variable, DISTRO, is automatically set to lmp. This distro is provided by the meta-lmp-base layer (see OpenEmbedded / Yocto Project Layers for more details).

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

MACHINE=qemuarm64-secureboot source setup-environment [BUILDDIR]

If MACHINE is not provided, the script will list all machines from 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. Keep in mind that BUILDDIR must be within the lmp directory, otherwise your build will fail.

Build the Image

You can build the LmP base-console image by running:

bitbake lmp-base-console-image

Note

Depending on the resources available on 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-base-console-image-raspberrypi3-64.wic.gz.

Install the Image

If you are using QEMU, follow the procedure outlined in the arm64 flashing instructions. See Board Machine Names for additional information on other targets.

Build and Install the LmP for your Factory

If you are already working with a Factory, you can instead download the source code for that factory with the following steps.

  1. Make and enter an installation directory for the LmP for your <factory-name>:

    mkdir <factory-name> && cd <factory-name>

  2. Install the <factory-name> meta-layers using repo:

repo init -u https://source.foundries.io/factories/<factory-name>/lmp-manifest.git -b main -m <factory-name>.xml
repo sync

The manifest <factory-name>.xml refers to all the LmP meta-layers and also to the <factory-name> specific repositories as described Factory Source Code.

  1. Build the image for <factory-name> with bitbake:
MACHINE=<machine-name> source setup-environment [BUILDDIR]
bitbake lmp-factory-image

The variable MACHINE should be set to a supported machine. See the current available option in Board Machine Names.

BUILDDIR is optional; in case it is not provided, the script default is build-lmp.

lmp-factory-image is the suggested default image, and can be customized with the steps from Adding Packages to the Image.

It is worth remembering that the bitbake step can take a while. At the end of the build, your build artifacts is found under deploy/images/<machine-name>. The artifact you use to flash your board is lmp-base-console-image-<machine-name>.wic.gz.

Important

The local build of your Factory is great for developing and debugging and the results can be used on the host machine or deployed to a hardware board. However, the image created locally is not yet visible for the OTA system, and is only available for local use.

When you push the changes to your Factory Git repos, it will trigger a new build. You can then flash and register your device following the instructions of Flashing Your Device and Registering Your Device. Then, you can take advantage of the OTA system.

References

The following reference material on OpenEmbedded and the Yocto Project is recommended for those unfamiliar.