3. First Steps with Yocto

3.1. Installing the BSP

  1. Start by creating a new project folder on your host machine:

$ mkdir ~/yocto

  1. Install phyLinux inside the new folder:

# 1. Download the file
$ wget https://download.phytec.de/Software/Linux/Yocto/Tools/phyLinux`

# 2. Change the access mode to be able to launch the program
$ chmod u+x phyLinux

# 3. Link python2 to python3 temporarily
$ ln -s which python2 python && export PATH=pwd:$PATH`

  1. Run phyLinux with ./phyLinux init and select the needed parameters for your device. Alternatively, use command-line arguments for settings. For example:

$ MACHINE=phyboard-mira-imx6-3 ./phyLinux init -p imx6 -r BSP-Yocto-Ampliphy-i.MX6-PD21.1.0

Choose parameters for the machine, platform, and release. After initialization, important notes and build process information will be displayed.

After the execution of the init command, phyLinux will print a few important notes as well as information for the next steps in the build process. For more information about phyLinux, you can check the PHYTEC Yocto Reference Manual.

3.2. Start the Build

After you download all the metadata with phyLinux init, you have to set up the shell environment variables. This needs to be done every time you open a new shell.

From the root of your project directory type:

$ source sources/poky/oe-init-build-env

The shell’s working directory should change to build/.

Before building for the first time, you should take a look at the main configuration file, your local modifications for the current build are stored here.

$ nano conf/local.conf

Depending on the SoC, you might need to accept license agreements. For some images using Freescale/NXP you have to uncomment the corresponding line.

# Uncomment to accept NXP EULA
# EULA can be found under ../sources/meta-freescale/EULA
ACCEPT_FSL_EULA = "1"

Now you are ready to build your first image. We suggest starting with our smaller non-graphical image phytec-headless-image to see if everything is working correctly:

$ bitbake phytec-headless-image

The initial build might take around about 40 minutes on a modern Intel Core i7. All subsequent builds will use the filled caches and should take about 3 minutes.

3.3. Installing the Image on a SD card

If the build worked, find the images in:

cd yocto/build/deploy/images/<MACHINE>

Copy the files with .sdcard or .wic extensions onto the SD card. To find them, you can use the command find:

find -name "*.wic"

Like in the Downloading a Bootable Image on the SD Card tutorial, you have to unmout the partitions and then copy the image on the SD Card. For example:

#unmount partitions of the SD Card
umount /dev/mmcblk0p1
umount /dev/mmcblk0p2

#Copy the image on the SD Card called mmcblk0
sudo dd if=phytec-kivydemo-image-phyboard-pollux-imx8mp-3.wic of=/dev/mmcblk0 bs=1M conv=fsync