A first Yocto build for the NXP i.MX 8M Quad EVK

2023 August Update

Please rely on the newly published project Build NXP iMX Embedded Linux instead of this one you are presently looking at. Although this project is still technically correct, the codeaurora repository no longer exists.

With so much documentation available it is easy to get lost when starting out.

This project demonstrates how to get started with a successful Yocto build for the i.MX 8M Quad EVK

Operating System

You may run Ubuntu either natively on a PC or within a VM, I have tested both methods successfully.

It may also be possible to run Ubuntu on WSL (Windows Subsystem for Linux) version 2, but I have not tested this yet.

These instructions assume that you are using one of these two versions of standard desktop Ubuntu:

• Ubuntu 18.04 LTS "Bionic Beaver" is the officially supported version for Yocto Zeus.
• Ubuntu 20.04 LTS "Focal Fossa" is what we are running on our machines, Yocto Zeus seems to work just fine.

These instructions also assume that you are using the default Bash shell that comes with Ubuntu.

Install packages

Note that the standard Ubuntu terminal application supports copy and paste with these keystrokes

• Copy <left shift> <control> c
• Paste <left shift> <control> v

Run the Ubuntu terminal application

Type in these commands to the terminal

$ sudo apt install gawk wget git-core diffstat unzip texinfo gcc-multilib 
$ sudo apt install build-essential chrpath socat cpio python python3 python3-pip python3-pexpect 
$ sudo apt install xz-utils debianutils iputils-ping python3-git python3-jinja2 libegl1-mesa libsdl1.2-dev 
$ sudo apt install pylint3 xterm 
$ sudo apt install curl

Install the Repo utility

Note: For Ubuntu 20.04 we must set up the Repo utility manually because Ubuntu 20.04 does not include Repo in the repositories without adding the focal-backports repository.

Follow these instructions for most versions of Ubuntu except 20.04

$ sudo apt install repo

That's it, skip all of the below and continue to the next section on setting up a Yocto directory

Follow the remaining instructions in this section for Ubuntu 20.04 or you want to make sure you are using the latest version of Repo. This is the method that I use.

Create directory ~/bin

$ mkdir ~/bin

Add ~/bin to your path for your present terminal session only

$ PATH="${HOME}/bin:${PATH}"

Additionally you can update your .bashrc file so that your PATH persists across all your login shells

$ cat >> ~/.bashrc

Copy and paste this line to the terminal

export PATH="${HOME}/bin:${PATH}"

Type <ctrl>-d to return to the $ prompt

Download repo

$ curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo

Change permissions of repo so that it can be executed

$ chmod a+rx ~/bin/repo

Set up a Yocto directory

Create the directory

$ mkdir Yocto

Move into the directory

$ cd Yocto

Confirm our PWD (Present Working Directory)

$ pwd

The result should be something like this

/home/flint/Yocto

Configure Git

List present configuration

$ git config --list

If the above command demonstrates that you already have a username and email configured then you can skip the remainder of this section and continue with configuring Repo.

Configure Git

$ git config --global user.name "Firstname Lastname"
$ git config --global user.email "EmailAddress@Domain.com"

Confirm that Git is configured properly

$ git config --list

You should see at least these two lines with your name and email address

user.name=Firstname Lastname
user.email=EmailAddress@Domain.com

Configure Repo and source the NXP imx-linux Yocto environment

First some Repo Definitions

<branch name>

• This is the generational version
• imx-linux-zeus is the latest at the time I wrote these instructions

<release manifest>

• This is the NXP release version on a 6 month cadence
• imx-5.4.47-2.2.0.xml is the latest at the time I wrote these instructions

Repo command syntax

repo init -u https://source.codeaurora.org/external/imx/imx-manifest -b <branch name> [ -m <release manifest>]

Confirm our PWD (Present Working Directory) is the./Yocto/ directory we built earlier

$ pwd

Initialize Repo

$ repo init -u https://source.codeaurora.org/external/imx/imx-manifest -b imx-linux-zeus -m imx-5.4.47-2.2.0.xml

Download the files

$ repo sync

View the contents of the directory

$ ls

You should now see the following folders / files

imx-setup-release.sh
README
README-IMXBSP
setup-environment
sources

Set up the Yocto build environment

First some Yocto definitions

MACHINE=<machine>

• use EVK names for <machine> listed in Yocto Project Users Guide, section 5.1 "Build configurations"

DISTRO=fsl-imx-<backend> where <backend> refers to the graphics type:

• xwayland = Wayland with X11 support - default distro
• wayland = Wayland only
• fb = Framebuffer (not supported for imx8)

Note: Each build folder can only support a single DISTRO

Command syntax

[MACHINE=<machine>] [DISTRO=fsl-imx-<backend>] source ./imx-setup-release.sh -b bld-<machine>-<backend>

Note that the filename bld-<machine>-<backend> is my personal recommendation and you are not required to follow this format

Confirm our PWD (Present Working Directory) is the./Yocto/ directory we built earlier

$ pwd

Set up the Yocto build environment

$ MACHINE=imx8mmevk DISTRO=fsl-imx-xwayland source imx-setup-release.sh -b bld-imx8mmevk-xwayland

Directory Structure

• The parent folder that we created manually ./Yocto/
• Our source directory created by Repo ./Yocto/sources/
• Our build directory created by imx-setup-release.sh./Yocto/bld-imx8mmevk-xwayland/
• The configuration files for bld-imx8mmevk-xwayland ./Yocto/bld-imx8mmevk-xwayland/conf/

Kick off the build

First some Bitbake Definitions

<recipe> These are pre-defined recipes specified in Yocto Project Users Guide, section 5.2

• imx-image-core = core image with basic graphics and no multimedia. This is a smaller image. It is also the image NXP uses for their daily build tests.
• imx-image-multimedia = image with multimedia and graphics. Builds an image with a GUI but without any Qt content.
• imx-image-full = image with multimedia and machine learning and Qt. Builds an open source QT 5 image with ML features.

Command syntax

bitbake <recipe>

Confirm our PWD (Present Working Directory)

$ pwd

Your PWD should be the build directory such as

/home/flint/Yocto/bld-imx8mmevk-xwayland

Kick off the build

$ bitbake imx-image-core

This will take a very long time and consume a lot of disk space.......

Returning to this project at a later date

Note: Bitbake will not run if the environment is not configured.

If you close the present shell (terminal) then you will lose the environment set up by imx-setup-release.sh

To set up our environment again

First make sure that PWD is./Yocto/

Then run this command

$ source setup-environment bld-imx8mmevk-xwayland