Patch for device tree - yocto

I am trying to configure and update my device tree by adding a node to it using a patch file created using quilt and building it with yocto.
made the bbappend recipe of the one already present in the BSP layer of the kernel directory.
patches are getting compiled but failing to update the source code and the node I am trying to create on my board is not reflected running kernel.
#this recipe is used to modify the kernel files
DESCRIPTION = "Patch file for kernel"
FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
SRC_URI_append = " \
file://001-adding-headers-msm8909-mdss-panels-dtsi.patch \
file://001-SPI3-Node-msm8909-pinctrl-dtsi.patch \
file://001-adding-node-to-config-msm8909-dtsi.patch \
file://001-spi0-i2c-node-msm8909-mtp-dtsi.patch \
"
whereas patch files also point to the exact source code I am trying to modify.
What is the area I am missing over it? The data I am trying to add with help of a patch is working fine if I directly paste it to the source code of the device tree. but trying to add it with help of a patch because not want to modify BSP-layer doing the changes within my local layer.

Related

How bitbake searches for recipe in build process?

I am trying to find out that how bitbake search for recipe in build process ?
For example,
I have a recipe something like below:
DESCRIPTION = "PetaLinux GSTREAMER supported packages"
inherit packagegroup
GSTREAMER_PACKAGES = " \
gstreamer1.0 \
gstreamer1.0-python \
gstreamer1.0-meta-base \
gstreamer1.0-plugins-base \
gstreamer1.0-plugins-good \
gstreamer1.0-plugins-bad \
gstreamer1.0-rtsp-server \
gst-shark \
gstd \
gst-perf \
gst-interpipes \
"
GSTREAMER_PACKAGES_append_zynqmp = " gstreamer1.0-omx"
RDEPENDS_${PN} = "${GSTREAMER_PACKAGES}"
When I searched gstreamer1.0 related recipe in yocto layers, I found two recipe, one of them is gstreamer1.0_1.16.1.bb in meta layer, and the other is gstreamer1.0_%.bbappend in meta-petalinux layer.
Both of these layers was added to the BBLAYERS in bblayers.conf file and the priorities that spesified with BBFILE_PRIORITY_* in related layer's layer.conf file is same.
So,
Which recipe will be used in build process in that case ?
What is the recipe lookup rules in yocto ?
I changed somethings to understand the behaviour:
For example,
I entered the invalid github URL that spesified in gstreamer1.0_%.bbappend recipe. When I tried to build the linux system, I encountered with an error. Thats fine.
Then I corrected the github URL in this recipe and entered invalid source code address that spesified in gstreamer1.0_1.16.1.bb recipe. When I tried to build linux system, process finished successfully.
Then I increased the priority of meta layer. I supposed to encounter with an error in this case but again build process finished successfully.
Could you please help me to understand this behaviour ?
Thanks.
You have two different files: a .bb and a .bbappend.
A .bb is the base recipe of one (or multiple) packages. It generally describe how to fetch, configure, compile, install files in a package for your target.
A .bbappend file is an 'append' file. It allows a meta (here meta-petalinux) to modify an existing recipe in another meta without copying it. A .bbappend can modify any steps of the bb file: source fetch, configure, compile, install...
You can for example create your own bbappend of Gstreamer, to enable pango (disbaled by default on my Yocto). The bbappend filename is gstreamer1.0-plugins-base_%.bbappend and only contains PACKAGECONFIG_append = "pango"
The Yocto Manual can give you more information on bbappend files here.

How can I get "HelloWorld - BitBake Style" working on a newer version of Yocto?

In the book "Embedded Linux Systems with the Yocto Project", Chapter 4 contains a sample called "HelloWorld - BitBake style". I encountered a bunch of problems trying to get the old example working against the "Sumo" release 2.5.
If you're like me, the first error you encountered following the book's instructions was that you copied across bitbake.conf and got:
ERROR: ParseError at /tmp/bbhello/conf/bitbake.conf:749: Could not include required file conf/abi_version.conf
And after copying over abi_version.conf as well, you kept finding more and more cross-connected files that needed to be moved, and then some relative-path errors after that... Is there a better way?
Here's a series of steps which can allow you to bitbake nano based on the book's instructions.
Unless otherwise specified, these samples and instructions are all based on the online copy of the book's code-samples. While convenient for copy-pasting, the online resource is not totally consistent with the printed copy, and contains at least one extra bug.
Initial workspace setup
This guide assumes that you're working with Yocto release 2.5 ("sumo"), installed into /tmp/poky, and that the build environment will go into /tmp/bbhello. If you don't the Poky tools+libraries already, the easiest way is to clone it with:
$ git clone -b sumo git://git.yoctoproject.org/poky.git /tmp/poky
Then you can initialize the workspace with:
$ source /tmp/poky/oe-init-build-env /tmp/bbhello/
If you start a new terminal window, you'll need to repeat the previous command which will get get your shell environment set up again, but it should not replace any of the files created inside the workspace from the first time.
Wiring up the defaults
The oe-init-build-env script should have just created these files for you:
bbhello/conf/local.conf
bbhello/conf/templateconf.cfg
bbhello/conf/bblayers.conf
Keep these, they supersede some of the book-instructions, meaning that you should not create or have the files:
bbhello/classes/base.bbclass
bbhello/conf/bitbake.conf
Similarly, do not overwrite bbhello/conf/bblayers.conf with the book's sample. Instead, edit it to add a single line pointing to your own meta-hello folder, ex:
BBLAYERS ?= " \
${TOPDIR}/meta-hello \
/tmp/poky/meta \
/tmp/poky/meta-poky \
/tmp/poky/meta-yocto-bsp \
"
Creating the layer and recipe
Go ahead and create the following files from the book-samples:
meta-hello/conf/layer.conf
meta-hello/recipes-editor/nano/nano.bb
We'll edit these files gradually as we hit errors.
Can't find recipe error
The error:
ERROR: BBFILE_PATTERN_hello not defined
It is caused by the book-website's bbhello/meta-hello/conf/layer.conf being internally inconsistent. It uses the collection-name "hello" but on the next two lines uses _test suffixes. Just change them to _hello to match:
# Set layer search pattern and priority
BBFILE_COLLECTIONS += "hello"
BBFILE_PATTERN_hello := "^${LAYERDIR}/"
BBFILE_PRIORITY_hello = "5"
Interestingly, this error is not present in the printed copy of the book.
No license error
The error:
ERROR: /tmp/bbhello/meta-hello/recipes-editor/nano/nano.bb: This recipe does not have the LICENSE field set (nano)
ERROR: Failed to parse recipe: /tmp/bbhello/meta-hello/recipes-editor/nano/nano.bb
Can be fixed by adding a license setting with one of the values that bitbake recognizes. In this case, add a line onto nano.bb of:
LICENSE="GPLv3"
Recipe parse error
ERROR: ExpansionError during parsing /tmp/bbhello/meta-hello/recipes-editor/nano/nano.bb
[...]
bb.data_smart.ExpansionError: Failure expanding variable PV_MAJOR, expression was ${#bb.data.getVar('PV',d,1).split('.')[0]} which triggered exception AttributeError: module 'bb.data' has no attribute 'getVar'
This is fixed by updating the special python commands being used in the recipe, because #bb.data was deprecated and is now removed. Instead, replace it with #d, ex:
PV_MAJOR = "${#d.getVar('PV',d,1).split('.')[0]}"
PV_MINOR = "${#d.getVar('PV',d,1).split('.')[1]}"
License checksum failure
ERROR: nano-2.2.6-r0 do_populate_lic: QA Issue: nano: Recipe file fetches files and does not have license file information (LIC_FILES_CHKSUM) [license-checksum]
This can be fixed by adding a directive to the recipe telling it what license-info-containing file to grab, and what checksum we expect it to have.
We can follow the way the recipe generates the SRC_URI, and modify it slightly to point at the COPYING file in the same web-directory. Add this line to nano.bb:
LIC_FILES_CHKSUM = "${SITE}/v${PV_MAJOR}.${PV_MINOR}/COPYING;md5=f27defe1e96c2e1ecd4e0c9be8967949"
The MD5 checksum in this case came from manually downloading and inspecting the matching file.
Done!
Now bitbake nano ought to work, and when it is complete you should see it built nano:
/tmp/bbhello $ find ./tmp/deploy/ -name "*nano*.rpm*"
./tmp/deploy/rpm/i586/nano-dbg-2.2.6-r0.i586.rpm
./tmp/deploy/rpm/i586/nano-dev-2.2.6-r0.i586.rpm
I have recently worked on that hands-on hello world project. As far as I am concerned, I think that the source code in the book contains some bugs. Below there is a list of suggested fixes:
Inheriting native class
In fact, when you build with bitbake that you got from poky, it builds only for the target, unless you mention in your recipe that you are building for the host machine (native). You can do the latter by adding this line at the end of your recipe:
inherit native
Adding license information
It is worth mentioning that the variable LICENSE is important to be set in any recipe, otherwise bitbake rises an error. In our case, we try to build the version 2.2.6 of the nano editor, its current license is GPLv3, hence it should be mentioned as follow:
LICENSE = "GPLv3"
Using os.system calls
As the book states, you cannot dereference metadata directly from a python function. Which means it is mandatory to access metadata through the d dictionary. Bellow, there is a suggestion for the do_unpack python function, you can use its concept to code the next tasks (do_configure, do_compile):
python do_unpack() {
workdir = d.getVar("WORKDIR", True)
dl_dir = d.getVar("DL_DIR", True)
p = d.getVar("P", True)
tarball_name = os.path.join(dl_dir, p+".tar.gz")
bb.plain("Unpacking tarball")
os.system("tar -x -C " + workdir + " -f " + tarball_name)
bb.plain("tarball unpacked successfully")
}
Launching the nano editor
After successfully building your nano editor package, you can find your nano executable in the following directory in case you are using Ubuntu (arch x86_64):
./tmp/work/x86_64-linux/nano/2.2.6-r0/src/nano
Should you have any comments or questions, Don't hesitate !

Yocto: Install different config files based on MACHINE type or target image

I've got a couple of HW platforms (same cpu, etc.) that require different asound.conf files.
The way that I'm controlling the target platform is via the MACHINE variable and target image (i.e., MACHINE=machine_1 nice bitbake machine-1-bringup-image)
Normally, if just replacing the conf file I'd just create an alsa-state.bbappend and create a do_install_append function to replace it.
However since the different HW platforms require differ conf files I'm unsure how to handle it.
I've tried putting some logic into the append file do_install_append function but it's not working out. It's not always picking up the correct file (like it thinks that nothing has changed so that it uses the previous cached conf?)
Here's an example of one of the append files that I've tried:
FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
SRC_URI += " \ file://asound_MACHINE1.conf \
file://asound_MACHINE2.conf \ "
do_install_append() {
echo " alsa-state.bbappend MACHINE: ${MACHINE}"
if [ "${MACHINE}" = "machine_1" ]; then
echo " machine_1"
echo " installing ${WORKDIR}/asound_MACHINE1.conf to ${D}${sysconfdir}/asound.conf"
install -m 644 ${WORKDIR}/asound_MACHINE1.conf {D}${sysconfdir}/asound.conf
else
echo " installing ${WORKDIR}/asound_MACHINE2.conf to ${D}${sysconfdir}/asound.conf"
install -m 644 ${WORKDIR}/asound_MACHINE2.conf ${D}${sysconfdir}/asound.conf
fi
}
I can see the correct echoes in the logs per the logic.
At any rate I don't think that the path I'm going down is the best way to deal with this.
Is there a 'standard' way to have different files installed based on either the target image or MACHINE variable?
do_install_append () {
// install common things here
}
do_install_append_machine-1 () {
// install machine-1 specific things here
}
do_install_append_machine-2 () {
// install machine-2 specific things here
}
The value of MACHINE is automatically added to OVERRIDES, which can be used at the end of a function append to have a MACHINE-specific addition to a function.
Maybe useful: https://www.yoctoproject.org/docs/2.4/mega-manual/mega-manual.html#var-OVERRIDES
You can have configuration files in machine specific directories in your particular case (just a specific configuration file for each machine). OpenEmbedded will fetch the most specific one. The directory structure in your recipe directory will look like:
files/<machine1>/asound.conf
files/<machine2>/asound.conf
And your alsa-state.bbappend will contain just one line (you don't need to change do_install because alsa-state.bb already installs asound.conf):
FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
BTW: We are using that setup to have specific asound.state file per machine in our project.
Moreover, OpenEmbedded will detect that SRC_URI contains machine specific file and change the PACKAGE_ARCH accordingly, see: https://www.yoctoproject.org/docs/2.5/mega-manual/mega-manual.html#var-SRC_URI_OVERRIDES_PACKAGE_ARCH
Few more words on machine, distro or arch specific files: OE is trying to fetch the most specific file in file:// fetcher. It searches also in the directories named by distro (e.g files/<distro>/asound.conf) and architecture (e.g. armv7a, arm). It might be useful if you want to have file specific for some set of devices. More information: https://www.yoctoproject.org/docs/2.5/mega-manual/mega-manual.html#var-FILESOVERRIDES and also https://www.yoctoproject.org/docs/2.5/mega-manual/mega-manual.html#best-practices-to-follow-when-creating-layers (section "Place Machine-Specific Files in Machine-Specific Locations")
The above answer by clsulliv worked better than advertised. For future reference below is the append file I used:
FILESEXTRAPATHS_prepend:= "${THISDIR}/${PN}:"
SRC_URI += " \
file://machine1_asound.conf \
file://machine2_asound.conf \
"
do_install_append_machine1() {
echo " machine1"
echo " installing ${WORKDIR}/machine1_asound.conf to ${D}${sysconfdir}/asound.conf"
install -m 644 ${WORKDIR}/machine1_asound.conf ${D}${sysconfdir}/asound.conf
}
do_install_append_machine2() {
echo " machine2"
echo " installing ${WORKDIR}/machine2_asound.conf to ${D}${sysconfdir}/asound.conf"
install -m 644 ${WORKDIR}/machine2_asound.conf ${D}${sysconfdir}/asound.conf
}
Thanks for the help!

Buildroot Config Option for applying custom patch

I am new to buildroot and working to build Linaro with buildroot ..I have multiple fragment kernel config files and specified that in buildroot defconfig.
I have specified a custom kernel patches directory with BR2_LINUX_PATCH_DIR .
I dont have some of the config flags not set which are supposed to be there in the .config files..so i suspect that the Patches are applied successfully..so i tried giving a non existing location as Linux Patch dir and it does not give any error..
Is there anything other than giving value to BR2_LINUX_PATCH_DIR and what should be the format of the dir structure...in buildroot manual it says it should be
Package_name/patch name..For linux what should be the package name? It should be the same with which linux dir is created.for example for me it is linux-custom
Plz suggest and guide me in this.
Thanks in Advance
The option is named BR2_LINUX_KERNEL_PATCH, there is nothing named BR2_LINUX_PATCH_DIR. It applies all patches listed in this option (if those are files), or all files named *.patch if what's given in this option is a directory. See the code in linux/linux.mk:
define LINUX_APPLY_LOCAL_PATCHES
for p in $(filter-out ftp://% http://% https://%,$(LINUX_PATCHES)) ; do \
if test -d $$p ; then \
$(APPLY_PATCHES) $(#D) $$p \*.patch || exit 1 ; \
else \
$(APPLY_PATCHES) $(#D) `dirname $$p` `basename $$p` || exit 1; \
fi \
done
endef
Also, I would recommend that you watch the output of Buildroot: it shows everything it is doing, especially it lists the patches it applied. Look at the line >>> linux .... Patching, which is the marker for the beginning of the patching step of the linux package.

bitbake recipe - doing a simple copy of the image

I am attempting to write a recipe that would simple copy two files (MyfileA , MyfileB) to a specific directory when the overall image is built. This is what my directory structure looks like:
MyDir/MyRecipe.bb
MyDir/files/MyfileA
MyDir/files/MyfileB
I would like the two files to be copied to a folder in home (which would not exist initially hence the directories should be created)The folder lets say is called "Testfolder"
This is what my bitbake file looks like
DESCRIPTION = "Testing Bitbake file"
PR = "r0"
SRC_URI = "file://MyfileA \
file://MyfileB "
do_install() {
install -d MyfileA ~/TestFolder/
}
Kindly let me know if I am doing something wrong here?
When i run bitbake on this I get the following
The BBPATH variable is not set and bitbake did not find a conf/bblayers.conf file in the expected location.
Maybe you accidentally invoked bitbake from the wrong directory?
DEBUG: Removed the following variables from the environment: LANG, LS_COLORS, LESSCLOSE, XDG_RUNTIME_DIR, SHLVL, SSH_TTY, OLDPWD, LESSOPEN, SSH_CLIENT, MAIL, SSH_CONNECTION, XDG_SESSION_ID, _, BUILDDIR
Any help in this regard would be appreciated.
First of all, to create your own meta-layer, you should run command yocto-layer create MyRecipe in your Yocto Environment. This is to make sure that you have all the necessary element in your meta layer. Make sure to put the new meta-layer into conf/bblayers.conf
Creating HelloWorld Recipe Video can be found here
Second, to copy a file from one to another directories.
DESCRIPTION = "Testing Bitbake file"
SECTION = "TESTING"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
PR = "r0"
SRC_URI = "file://MyfileA \
file://MyfileB "
#specify where to get the files
S = "${WORKDIR}"
inherit allarch
#create the folder in target machine
#${D} is the directory of the target machine
#move the file from working directory to the target machine
do_install() {
install -d ${D}/TestFolder
install -m ${WORKDIR}/MyfileA ${D}/TestFolder
}
To get more in details, this is my understanding of how the files move around in Yocto.
You have a directory that stored metadata in /sourced/meta-mylayer/recipes-myRecipe/. In that directory, there would be a folder with the same name as the recipe. I.E. myRecipe/ myRecipe_001.bb.
You would store the files that are related to myRecipe.bb (usually it is a patch) in myRecipe/ so that SRC_URI will get into that myRecipe/ directory to grab files. I.E. myFileA, myFileB
Then, you specify the S. This is the location in the Build Directory where unpacked recipe source code resides. By that mean, myFileA and myFileB are moved/copied to there when myRecipe builds.
Usually, S is equal to ${WORKDIR}, this is equivalent to ${TMPDIR}/work/${MULTIMACH_TARGET_SYS}/${PN}/${EXTENDPE}${PV}-${PR}
The actual directory depends on several things:
TMPDIR: The top-level build output directory
MULTIMACH_TARGET_SYS: The target system identifier
PN: The recipe name
EXTENDPE: The epoch - (if PE is not specified, which is usually the case for most recipes, then EXTENDPE is blank)
PV: The recipe version
PR: The recipe revision
After that, we inherit allarch. This class is used for architecture independent recipes/data files (usually scripts).
Then, the last thing we have to do is copy the files.
${D} is the location in the Build Directory where components are installed by do_install task. This location defaults to ${WORKDIR}/image
${WORKDIR}/image can also be described as the / directory in the target system.
Go to ${D} directory and create a folder call TestFolder
Then, copy myFileA from ${WORKDIR} to the ${D}/TestFolder
P.S. Please add comment to fix. There might be mistaken information here, cause I learned all this by myself.