How to compile Linux with Qt5 option using Yocto for VisionSOM-STM32MP1 on Ubuntu 20.04

Instruction how to build an image for VisionSOM-STM32MP1 from SomLABS


The VisionSOM-STM32MP1 (SLS18)

The Carrier board

General Note:

Assumed that Linux Ubuntu 20.04 is installed

List of tested elements

The hearthbeat LED works

List of not tested elements

Bluetooth โ€“ appears during system boot up
Backlight for Lcd

How to build images

1. First, make sure to following packages are installed in the system

sudo apt-get install gawk wget diffstat unzip texinfo gcc-multilib build-essential chrpath socat libsdl1.2-dev xterm libncurses5-dev git

Note: More information can be found on the Yocto reference manual.

2. Download necessary Yocto packaged listed below. Be sure to be in the root of the home folder.

mkdir yocto 
cd yocto 
mkdir build 
git clone git:// --depth 1 -b dunfell
cd poky 
git clone git:// --depth 1 -b dunfell
git clone --depth 1 -b dunfell
git clone --depth 1 -b dunfell

3. Select directory to build Linux

source oe-init-build-env ~/yocto/build/stm32mp157a-visionsom

4. Modify bblayers.conf(located in ~/yocto/build/stm32mp157a-visionsom/conf)

${HOME}/yocto/poky/meta \
${HOME}/yocto/poky/meta-poky \
${HOME}/yocto/poky/meta-openembedded/meta-webserver \
${HOME}/yocto/poky/meta-openembedded/meta-gnome \
${HOME}/yocto/poky/meta-openembedded/meta-xfce \
${HOME}/yocto/poky/meta-openembedded/meta-initramfs \
${HOME}/yocto/poky/meta-openembedded/meta-multimedia \
${HOME}/yocto/poky/meta-openembedded/meta-filesystems \
${HOME}/yocto/poky/meta-openembedded/meta-perl \
${HOME}/yocto/poky/meta-openembedded/meta-oe \
${HOME}/yocto/poky/meta-openembedded/meta-networking \
${HOME}/yocto/poky/meta-openembedded/meta-python \
${HOME}/yocto/poky/meta-qt5 \
${HOME}/yocto/poky/meta-stm32mp1 \

Note: Please adapt PATH of conf/bblayers.conf if necessary.

5. Modify or align following elements in local.conf(located in ~/yocto/build/stm32mp157a-visionsom/conf) file

MACHINE ??= "stm32mp157c-visionsom"
DL_DIR = "${HOME}/yocto/downloads"
SSTATE_DIR = "${HOME}/yocto/sstate-cache"
TMPDIR = "${HOME}/yocto/tmp"
INHERIT += "rm_work"

Note: Please adapt rest of conf/local.conf parameters if necessary.

6. Build objects

Issue from console one of the following option

qt5 image 
bitbake qt5-image

qt5 toolchain sdk 
bitbake meta-toolchain-qt5

7. After a couple of hours, ๐Ÿ˜‰ the image should be ready

8. Create image for SD-Card using a dedicated script. So type

gunzip -c ~/yocto/tmp/deploy/images/stm32mp157c-visionsom/qt5-image-stm32mp157c-visionsom-xxx.rootfs.wic.gz | sudo dd of=/dev/mmcblk0 bs=1M iflag=fullblock oflag=direct conv=fsync

NOTE: Only thing to do is replace if necessary of=/dev/mmcblk0 to of=/dev/sdx for instance. Be aware wrong specification of โ€œof=/dev/..โ€ can damage Your local system, check twice !. To check where the SD-Card is connected โ€œdf -hโ€ command can be useful

9. Next, compile QT5 toolchain in Yocto.

bitbake meta-toolchain-qt5

NOTE: During compilation some WARNINGS can appears

10. Next step is to install SDK into the system. Go to directory

cd tmp/deploy/sdk/

11. The Last thing to do is create Kit for STM32 into the QTCreator application. Please refer to the following article and apply accordingly

Lucjan Bryndza

Embedded software engineer