Extends kernel configuration

[giraldeau]

The bitbake build process configures the kernel using .cfg files. However, the meta-raspberrypi linux-rpi.inc creates a config file and calls make oldconfig. Is there a reason why the configuration is done this way? What would be the prefered way to extends the kernel configuration with additional parameters?

Thanks!

[agherzan]

Hi. I was under the impression that we fixed this in the past by adding support for yocto config fragments. I haven't tested it in a while but I did it now and indeed it seems broken. We use the make oldconfig because we use a defconfig from the kernel tree repository.

[yongli3]

@agherzan I encountered this issue too. I cannot change the kernel config using the fragments cfg files(https://github.com/jumpnow/meta-rpi/issues/2). I found there is a patch about it: https://lists.yoctoproject.org/pipermail/yocto/2015-August/026101.html, can we merge it?

[izak]

Ran into the same problem. Lost about a day trying to figure out why the patch works but the config is flatly ignored. Eventually applied the patch above and it appears to be the perfect solution.

[toolmmy]

I'm not quite sure, bit it seems that the fragments are applied within the kernel_configme task (see kernel-yocto.inc addtask kernel_configme before do_configure after do_patch) before do_configure.

The do_configure of the linux-rpi.inc clears the complete .config in order to create a new one so all changes applied by the fragments are gone.

[xkrys]

I'm also struggling with this, I want to add some support for can devices from my custom layers but changes from kernel fragments are ignored, any plan to support fragments for configuring kernel?

[agherzan]

There were some patches in the mailing list in this regards. If anyone has a little bit of time, a PR would be great.

[ollyw]

Hi all, I tried the patches on the mailing list and extended for RPI3. I will put in a PR once it works, however, it doesn't seem to work fully, and I wondered if I could get some help?

I get a QA error that the /lib folder is not shipped. I can't see why the patches from https://lists.yoctoproject.org/pipermail/yocto/2015-August/026101.html would cause that issue as they don't seem to include changes to the FILES_ variables, and my fragment is compiling in kernel features rather than adding modules. Any pointers as to how to debug this would be great, then I can finish the PR. Apologies in advance, I am relatively new to yocto and new to the meta-raspberrypi layer custom kernel config stuff

[pbrkr]

@agherzan, @giraldeau, @andig75 : Can this be closed now? Looks like the pull request above has been merged and should resolve this.

[agherzan]

Yes. I personally tested this lately. Works just fine.

[mardy]

This doesn't work for me. I'm trying to enable CONFIG_SECURITY_APPARMOR and a couple of other related options, but I don't see any of my changes in the final configuration (tmp/work/raspberrypi3-pelux-linux-gnueabi/linux-raspberrypi/1_4.9.59+gitAUTOINC+e7976b2aff-r0/image/boot/config-4.9.59). I do see my fragment (apparmor.cfg) being loaded in tmp/work/raspberrypi3-pelux-linux-gnueabi/linux-raspberrypi/1_4.9.59+gitAUTOINC+e7976b2aff-r0/temp/run.do_kernel_metadata and I see my changes in tmp/work-shared/raspberrypi3/kernel-source/.meta/cfg/.config but it looks like that it's all in vain.

It looks like that that .config file is not being loaded, with tmp/work/raspberrypi3-pelux-linux-gnueabi/linux-raspberrypi/1_4.9.59+gitAUTOINC+e7976b2aff-r0/linux-raspberrypi3-standard-build/.config being loaded instead of it. Is this expected, am I doing something wrong?

[kraj]

@mardy yes tmp/work/raspberrypi3-pelux-linux-gnueabi/linux-raspberrypi/1_4.9.59+gitAUTOINC+e7976b2aff-r0/linux-raspberrypi3-standard-build/.config is the final config which is applied during build.

[mardy]

@kraj Thanks for confirming that. Do you know then what is the bitbake step which should move the config file in tmp/work-shared/raspberrypi3/kernel-source/.meta/cfg/.config into tmp/work/raspberrypi3-pelux-linux-gnueabi/linux-raspberrypi/1_4.9.59+gitAUTOINC+e7976b2aff-r0/linux-raspberrypi3-standard-build/.config?

[mardy]

I found out the problem: my fragment contained CONFIG_SECURITY_APPARMOR="y", but this was not included in the final config file because it depends on CONFIG_SECURITY, which is disabled in the default configuration. After adding also CONFIG_SECURITY="y", it works.

Sorry for the noise! :-)