Qt for Embedded Linux(raspberry pi)

bblayers.conf

# POKY_BBLAYERS_CONF_VERSION is increased each time build/conf/bblayers.conf
# changes incompatibly
POKY_BBLAYERS_CONF_VERSION = "2"

BBPATH = "${TOPDIR}"
BBFILES ?= ""

BBLAYERS ?= " \
    ${HOME}/poky-dunfell/meta \
    ${HOME}/poky-dunfell/meta-poky \
    ${HOME}/poky-dunfell/meta-openembedded/meta-oe \
    ${HOME}/poky-dunfell/meta-openembedded/meta-multimedia \
    ${HOME}/poky-dunfell/meta-openembedded/meta-networking \
    ${HOME}/poky-dunfell/meta-openembedded/meta-perl \
    ${HOME}/poky-dunfell/meta-openembedded/meta-python \
    ${HOME}/poky-dunfell/meta-qt5 \
    ${HOME}/poky-dunfell/meta-raspberrypi \
    ${HOME}/poky-dunfell/meta-jumpnow \
    ${HOME}/poky-dunfell/meta-security \
    ${HOME}/rpi/meta-rpi \
"

cmds_paths.txt

bitbake -g <image> && cat pn-buildlist | grep -ve "native" | sort | uniq    -> list image packages
bitbake -s | grep <pkg>	                                                    -> Check if certain package is present on current 

build/tmp/work/cortexa7t2hf-neon-vfpv4-poky-linux-gnueabi/qtbase/5.13.2+gitAUTOINC+a7a24784ee-r0/build/config.summary   -> Check egfls or other things

Instruction.txt

This is an instruction of building Raspberry Pi systems with Yocto Project.

1# Below packages must installed on your host system(18.04 or 20.04 ubuntu).
build-essential, chrpath, diffstat, gawk, libncurses5-dev, python3-distutils, texinfo

2# You should change the default Ubuntu shell from dash to bash by running this command from a shell:
sudo dpkg-reconfigure dash  :: Choose No to dash when prompted.

3# First clone the main Yocto project poky layer with this command:
~$ git clone -b dunfell git://git.yoctoproject.org/poky.git poky-dunfell

4# Then the dependency layers under that:
~$ cd poky-dunfell
~/poky-dunfell$ git clone -b dunfell git://git.openembedded.org/meta-openembedded
~/poky-dunfell$ git clone -b dunfell https://github.com/meta-qt5/meta-qt5
~/poky-dunfell$ git clone -b dunfell git://git.yoctoproject.org/meta-raspberrypi
~/poky-dunfell$ git clone -b dunfell git://git.yoctoproject.org/meta-security.git

5# Changing some upstream package defaults and adding a few custom recipes(I didn't compile it)
~/poky-dunfell$ git clone -b dunfell https://github.com/jumpnow/meta-jumpnow

6# Create a separate sub-directory for the meta-rpi repository before cloning. This is where you will be doing your customization
~$ mkdir ~/rpi
~$ cd ~/rpi
~/rpi$ git clone -b dunfell git://github.com/jumpnow/meta-rpi

7# Initialize the build directory
~$ source poky-dunfell/oe-init-build-env ~/rpi/build(this one has different machine names)
or
$ mkdir -p ~/rpi/build/conf(this one has machine names of raspberrypi devices)
~/rpi$ cp meta-rpi/conf/local.conf.sample build/conf/local.conf
~/rpi$ cp meta-rpi/conf/bblayers.conf.sample build/conf/bblayers.conf

Warning: Do not use the ‘~’ character when defining directory paths in the Yocto configuration files.

8# Edit bblayer.conf according to below file which named bblayers.conf.

9# Edit local.conf according to below file which named local.
The important things in local.conf:

DL_DIR = "/home/merdak/rpi/build/sources"             - Fetched files in here
SSTATE_DIR = "/home/merdak/rpi/build/sstate-cache"    
TMPDIR = "/home/merdak/rpi/build/tmp"                 - Compiled files in here

IMAGE_INSTALL_append_pn-qt5-image=" openssh"          - It might not installed openssh to qt5-image

DISTRO_FEATURES_remove = "x11"                        - In Qt5 there is no need X11 wayland platform
MACHINE_FEATURES_remove = "vc4graphics"               
PACKAGECONFIG_append_pn-qtbase = " eglfs"             - Activate eglfs
  
10# Run the build
~$ source poky-dunfell/oe-init-build-env ~/rpi/build
~/rpi/build$ bitbake qt5-image(it takes some time...)

If the build for qt5-image failed for some reason, run this commands in order:
~/rpi/build$ bitbake -c cleansstate qt5-image
~/rpi/build$ bitbake qt5-image

11# Copying the binaries to an SD card (or eMMC)
This script will partition an SD card with the minimal 2 partitions required for the RPI:
~$ cd ~/rpi/meta-rpi/scripts
~/rpi/meta-rpi/scripts$ sudo ./mk2parts.sh sdb (if you get mount errors, you must unmount before run the script)

12# Temporary mount point
You will need to create a mount point on your workstation for the copy scripts to use.
This is the default:
~$ sudo mkdir /media/card

13# copy_boot.sh
This script copies the GPU firmware, the Linux kernel, dtbs and overlays, config.txt and cmdline.txt to the boot partition of the SD card.
OETMP and MACHINE values must be exported before run the script:
~/rpi/meta-rpi/scripts$ export OETMP=/home/merdak/rpi/build/tmp(this is the TMPDIR direction in the local.conf file)
~/rpi/meta-rpi/scripts$ export MACHINE=raspberrypi0-wifi

~/rpi/meta-rpi/scripts$ ./copy_boot.sh sdb

14# copy_rootfs.sh
This script copies the root file system to the second partition of the SD card.
~/rpi/meta-rpi/scripts$ ./copy_rootfs.sh mmcblk0 qt5 rpi3(disk partition name, image name, user name)

15# Create toolchain
~/rpi/build$ bitbake meta-toolchain-qt5
This command will create files which named 'sdk' under /home/merdak/rpi/build/tmp/deploy
Go to this path and run the *.sh file.
This file will create 'sysroot' file under /opt/poky/3.1.9, unless otherwise stated.(Which means you can specify the 'export path' but don't)

16# Cross compile
In the sysroot file there are two files;
-arm1176jzfshf-vfp-poky-linux-gnueabi(this folder is an example of the target operational system)
-x86_64-pokysdk-linux(this folder for host pc to configure qt for target device)

17# Create kit for target device
Open Qt Creator, go to Tools->Options->Kits
For compilers:
Add a GCC and give the path:
/opt/poky/3.1.9/sysroots/x86_64-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi/arm-poky-linux-gnueabi-gcc
Add a G++ and give the path:
/opt/poky/3.1.9/sysroots/x86_64-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi/arm-poky-linux-gnueabi-g++
For debugger:
Add a GDB and give the path:
/opt/poky/3.1.9/sysroots/x86_64-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi/arm-poky-linux-gnueabi-gdb
For Qt Versions:
Add a version and give the path:
/opt/poky/3.1.9/sysroots/x86_64-pokysdk-linux/usr/bin/qmake
Finally add a kit and:
-Configure the device as Linux Generic Device
-Give sysroot path as: /opt/poky/3.1.9/sysroots/arm1176jzfshf-vfp-poky-linux-gnueabi
-Select compilers, debugger, and Qt version

18# Configure SSH
-Open the target device, configure /etc/wpa_supplicant and /etc/network/interfaces and reboot for internet connection
-Query the IP address of target device.
-Go to Qt and Tools->Options->Devices.
Host Name: target-device-ip
Username : Root
Leave default the other configurations.
Open a new project and configure for target device. When you play it, it will run on target device.

19# Play video & open Qt application on target device
Go to under /etc/init.d/ folder.
Create a shell script file(touch tem_start.sh) and modify:
  #!/bin/sh
  omxplayer -o /home/root/temterazi.mp4
Under /etc/init.d/ run this command:
  update-rc.d temstart.sh defaults(this cmd will add the script to startup)
Under /home/root create file(touch ~/.profile) and modify
  cd /home/root && ./qtapplication
With this operation, Qt application will start every log in.
  

links.txt

https://jumpnowtek.com/rpi/Raspberry-Pi-Systems-with-Yocto.html
https://askubuntu.com/questions/299792/why-is-the-command-in-etc-rc-local-not-executed-during-startup

local.conf

# Local configuration for meta-rpi images
# Yocto Project 3.1 Poky distribution [dunfell] branch
# This is a sysvinit system

# mask wireguard from meta-openembedded/meta-networking
# use version in meta-jumpnow to support kernels < 5.6
# with wireguard-linux-compat
BBMASK = "meta-networking/recipes-kernel/wireguard"

LICENSE_FLAGS_WHITELIST = "commercial"

DISTRO_FEATURES = "ext2 opengl usbhost ${DISTRO_FEATURES_LIBC}"

DISTRO_FEATURES_BACKFILL_CONSIDERED += "pulseaudio"

PREFERRED_PROVIDER_jpeg = "libjpeg-turbo"
PREFERRED_PROVIDER_jpeg-native = "libjpeg-turbo-native"

PREFERRED_PROVIDER_udev = "eudev"
VIRTUAL-RUNTIME_init_manager = "sysvinit"

MACHINE_FEATURES_remove = "apm"

IMAGE_FSTYPES = "tar.xz"

# Choose the board you are building for
#MACHINE = "raspberrypi"
#MACHINE = "raspberrypi0"
MACHINE = "raspberrypi0-wifi"
#MACHINE = "raspberrypi2"
#MACHINE = "raspberrypi3"
#MACHINE = "raspberrypi4"
#MACHINE = "raspberrypi-cm"
#MACHINE = "raspberrypi-cm3"

# Choices are Image or zImage if NOT using u-boot (no u-boot is the default)
# Choices are uImage or zImage if using u-boot, though if you choose zImage
# with u-boot you will also have to change the boot script boot command
KERNEL_IMAGETYPE = "zImage"

# uncomment for kernels < 5.6
WIREGUARD_COMPAT = "1"

DISABLE_VC4GRAPHICS = "1"
DISABLE_OVERSCAN = "1"
ENABLE_UART = "1"
ENABLE_RPI3_SERIAL_CONSOLE = "1"
SERIAL_CONSOLES = "115200;ttyAMA0"
# SERIAL_CONSOLES_forcevariable = ""

# default is still 4.19, uncomment the following for 5.4
# PREFERRED_VERSION_linux-raspberrypi = "5.4.%"


DL_DIR = "/home/merdak/rpi/build/sources"
SSTATE_DIR = "/home/merdak/rpi/build/sstate-cache"
TMPDIR = "/home/merdak/rpi/build/tmp"

DISTRO = "poky"
PACKAGE_CLASSES = "package_ipk"

# i686 or x86_64
SDKMACHINE = "x86_64"

# for no root passwd uncomment the following and comment the two extra user lines
EXTRA_IMAGE_FEATURES = "debug-tweaks"

# for a root passwd, change jumpnowtek below to your password
#INHERIT += "extrausers"
#EXTRA_USERS_PARAMS = "usermod -P jumpnowtek root; "

# this will force root to change password on first login
#INHERIT += "chageusers"
#CHAGE_USERS_PARAMS = "chage -d0 root; "

USER_CLASSES = "image-mklibs image-prelink"
PATCHRESOLVE = "noop"
RM_OLD_IMAGE = "1"
#INHERIT += "rm_work"
CONF_VERSION = "1"

DISTRO_FEATURES_remove = "x11"
MACHINE_FEATURES_remove = "vc4graphics"
PACKAGECONFIG_append_pn-qtbase = " eglfs"

#IMAGE_INSTALL_remove = "checksec ncrack"

IMAGE_INSTALL_append_pn-qt5-image=" openssh"

#BB_NUMBER_THREADS = "4"
#PARALLEL_MAKE = "-j6"