-
Notifications
You must be signed in to change notification settings - Fork 3
Creating a patch for an existing recipe source file
In this wiki, I describe the general steps I used in order to create a patch for u-boot-xlnx to disable the SD card as needed for gFEX prototype 3. One should be able to follow/understand the procedure here and repeat it for future recipes. The magic functionality here is the devtool command.
Let's start by running
devtool modify u-boot-xlnx
and the output looks like below
Loading cache: 100% |########################################################################################################################################################################| Time: 0:00:00
Loaded 2524 entries from dependency cache.
Parsing recipes: 100% |######################################################################################################################################################################| Time: 0:00:01
Parsing of 1748 .bb files complete (1747 cached, 1 parsed). 2525 targets, 176 skipped, 0 masked, 0 errors.
NOTE: Executing RunQueue Tasks
NOTE: Executing do_fetch...
NOTE: Executing do_unpack...
NOTE: Tasks Summary: Attempted 2 tasks of which 0 didn't need to be rerun and all succeeded.
NOTE: Patching...
NOTE: Executing RunQueue Tasks
NOTE: Executing do_patch...
NOTE: Tasks Summary: Attempted 3 tasks of which 2 didn't need to be rerun and all succeeded.
NOTE: Source tree extracted to /local/d4/gstark/poky/build/workspace/sources/u-boot-xlnx
NOTE: Recipe u-boot-xlnx now set up to build from /local/d4/gstark/poky/build/workspace/sources/u-boot-xlnx
Notice that the last line here indicates that it has extracted the source for u-boot-xlnx to /local/d4/gstark/poky/build/workspace/sources/u-boot-xlnx. If you go into this directory, in this case, you'll notice that it's a git repository!
Make the necessary changes you need to make to the source code. E.G.
cd workspace/sources/u-boot-xlnx
vim include/configs/xilinx_zynqmp_zcu102.h
# make changes
You can run bitbake u-boot-xlnx to recompile and use the devtool deploy-target to copy files over to the target machine. [I did not try this]
Once you've made the changes, you will need to create a commit containing those changes.
git add include/configs/xilinx_zynqmp_zcu102.h
git commit -m "a helpful description of what I just did and why"
The last thing is to generate the necessary .bbappends and .patch files and store them in the meta-l1calo layer I work with. The way to do this is to let devtool handle this for you by comparing differences between the local source repo and the remote source repo.
First I need to go back to my actual workspace
cd ../../../
and then let devtool generate the necessary files
devtool update-recipe -m patch -a /path/to/meta-l1calo/ u-boot-xlnx
and the output looks like
Loading cache: 100% |########################################################################################################################################################################| Time: 0:00:00
Loaded 2524 entries from dependency cache.
Parsing recipes: 100% |######################################################################################################################################################################| Time: 0:00:01
Parsing of 1748 .bb files complete (1746 cached, 2 parsed). 2525 targets, 176 skipped, 0 masked, 0 errors.
NOTE: Writing append file /local/d4/gstark/meta-l1calo/recipes-bsp/u-boot/u-boot-xlnx_2017.1.bbappend
NOTE: Writing append file /local/d4/gstark/meta-l1calo/recipes-bsp/u-boot/u-boot-xlnx_2017.1.bbappend
NOTE: Copying 0001-no-SDCard-available-for-gFEX-prototype-v3.patch to /local/d4/gstark/meta-l1calo/recipes-bsp/u-boot/u-boot-xlnx/0001-no-SDCard-available-for-gFEX-prototype-v3.patch
NOTE: Copying 0001-no-SDCard-available-for-gFEX-prototype-v3.patch to /local/d4/gstark/meta-l1calo/recipes-bsp/u-boot/u-boot-xlnx/0001-no-SDCard-available-for-gFEX-prototype-v3.patch
Notice that the patch files will contain the short commit message in the name to help you identify which patch is which. The patch files are part of the SRC_URI for bitbake/yocto while the .bbappends are what defines recipes for including those source files!
Now we get to clean up our local changes. First run
devtool reset u-boot-xlnx
which outputs
NOTE: Cleaning sysroot for recipe u-boot-xlnx...
NOTE: Leaving source tree /local/d4/gstark/poky/build/workspace/sources/u-boot-xlnx as-is; if you no longer need it then please delete it manually
Notice that it informs us that it leaves the workspace as it. We can (and should) delete the u-boot-xlnx sources:
rm -rf workspace/sources/u-boot-xlnx
The last thing we need to do is make sure that the .bbappends only applies the patch for the specific board gfex-prototype3 that needs it. In this case, we go to the meta-l1calo layer where devtool made all the changes, and then edit recipes-bsp/u-boot/u-boot-xlnx_2017.1.bbappend:
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
SRC_URI += "file://0001-no-SDCard-available-for-gFEX-prototype-v3.patch"
and change SRC_URI to add an append operation to a specific machine
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
SRC_URI_append_gfex-prototype3 += "file://0001-no-SDCard-available-for-gFEX-prototype-v3.patch"
and this will only patch the ZynqMP ZCU102 header file for u-boot if the target machine is gfex-prototype3.