About Yocto system
Ctrl C + Ctrl V frome the web-site ibm.com "The Yocto Project™ – is an Open Source-project, which purpose is to make the development of special Linux distributions for embedded systems and ensuring their portability across different platforms easier."
Below are the basic first steps when meeting with yocto.
The building process is described in the documentation in detail.
After installing/unpacking the distribution we have something like this folder with the following content:
$ ls -l итого 240 drwxr-xr-x 6 dima dima 4096 дек. 16 09:16 bitbake drwxr-xr-x 13 dima dima 4096 дек. 16 09:16 documentation -rw-r--r-- 1 dima dima 14664 дек. 16 09:16 fsl-setup-poky -rw-r--r-- 1 dima dima 545 дек. 16 09:16 LICENSE drwxr-xr-x 21 dima dima 4096 дек. 16 09:16 meta drwxr-xr-x 17 dima dima 4096 дек. 16 09:21 meta-fsl-networking drwxr-xr-x 13 dima dima 4096 дек. 16 09:16 meta-fsl-ppc drwxr-xr-x 7 dima dima 4096 дек. 16 09:21 meta-fsl-ppc-toolchain drwxr-xr-x 4 dima dima 4096 дек. 16 09:16 meta-hob drwxr-xr-x 16 dima dima 4096 дек. 16 09:16 meta-oe drwxr-xr-x 6 dima dima 4096 дек. 14 17:01 meta-skeleton drwxr-xr-x 11 dima dima 4096 дек. 16 09:21 meta-virtualization drwxr-xr-x 6 dima dima 4096 дек. 14 17:01 meta-yocto drwxr-xr-x 8 dima dima 4096 дек. 14 17:01 meta-yocto-bsp -rwxr-xr-x 1 dima dima 1592 дек. 16 09:16 oe-init-build-env -rw-r--r-- 1 dima dima 2038 дек. 16 09:16 README -rw-r--r-- 1 dima dima 17436 дек. 16 09:16 README.hardware drwxr-xr-x 9 dima dima 4096 дек. 16 09:16 scripts drwxr-xr-x 11 dima dima 131072 марта 3 16:07 sources drwxrwxr-x 260 dima dima 4096 дек. 18 04:41 sstate-cache
Next we need to install the missing packages using the script
$ . /scripts/host-prepare.sh
The next step is the yocto configurationfor the building under specific target.
For example:
source ./fsl-setup-poky -m p5040rdb -j14 -t14
After this command running we get the work folder, in my case it is the following folder: build_p5040rdb_release
We go to this folder and begin with the building. It can be done using bitbake. For example:
$ bitbake fsl-image-minimal
When using graphics we start the programm hob
$ hob
Using hob we can choose a target, building image, to set the number of parallel threads to speed up building time, etc.
After building of Yocto Project, we can find the images in
build_p5040ds_release/tmp/deploy/images
Cross-compiler is located somewhere here (search by mask "-linux-gcc"):
/build_p5040ds_release/tmp/sysroots
Sometimes when running bitbake or hob we can see this message:
ERROR: Only one copy of bitbake should be run against a build directory
It means that bitbake have been already started:
ps -ef|grep bitbake
compiled packages are located in
/build_p5040ds_release/tmp/work/
If we want to remove some package, we need to use bitbake as follows:
bitbake -c clean virtual/kernel bitbake -c cleansstate pulseaudio bitbake -c cleansstate u-boot
For configuration of the linux kernel in Yocto Project:
bitbake -c menuconfig virtual/kernel
For building of linux kernel in Yocto Project:
$ bitbake -c compile -f virtual/kernel $ bitbake virtual/kernel
Kernel configuration for the specific system in Yocto Project:
MACHINE=p5040ds bitbake -c menuconfig virtual/kernel
Kernel building for the specific system in Yocto Project:
$ MACHINE=p5040ds-64b bitbake -c compile -f virtual/kernel $ MACHINE=p5040ds-64b bitbake virtual/kernel
In case if we got such a message:
ERROR: OE-core's config sanity checker detected a potential misconfiguration.
Either fix the cause of this error or at your own risk disable the checker (see sanity.conf).
Following is the list of potential problems / advisories:
Toolchain tunings invalid:
Multilib 'lib64' (ppc64e5500) is also the default tuning.
ERROR: Execution of event handler 'check_sanity_eventhandler' failed
we comment all the lines in the file meta/conf/sanity.conf as follows (I don't know what it means, but it works):
#BB_MIN_VERSION = "1.17.1"
#SANITY_ABIFILE = "${TMPDIR}/abi_version"
#SANITY_VERSION ?= "1"
#LOCALCONF_VERSION ?= "1"
#LAYER_CONF_VERSION ?= "5"
#SITE_CONF_VERSION ?= "1"
#INHERIT += "sanity"
Adding of a new package to the building target of core-image-minimal:
1. To create the building recipe and it is better to download it from the Internet, because it surely is already there. Then copy it over here as an option: poky/meta/recipes-devtools
2. To add the following line into the file poky/build/conf/local.conf:
CORE_IMAGE_EXTRA_INSTALL = "efibootmgr"
or so:
IMAGE_INSTALL_append = " lua5.1 efibootmgr"
where efibootmgr - is the name of the new package and the similar name of the building recipe in poky/meta/recipes-devtools
3. To run the building process using hob and make sure that the package have been added while building of the target core-image-minimal.
Building of separate utilities in the system of yocto is performed according to the available list of commands for each utility. The list of commands can be viewed, for example, for the utility efibootmgr:
$ bitbake -c listtasks efibootmgr
For removing the utility with the source codes from tmp/work/corei7-64-poky-linux/efibootmgr:
bitbake -c cleansstate efibootmgr
For utility building:
bitbake -c compile efibootmgr
The option "-v" displays a detailed output of information about the building process:
bitbake -v -c compile efibootmgr
