[meta-xilinx] Overwriting kmeta-based config options in own layer

[Nathan Rossi]

On Wed, Aug 26, 2015 at 1:17 PM, Andreas Galauner <andreas at galauner.de> wrote:
> On 25.08.2015 08:56, Nathan Rossi wrote:
>> But you probably don't need to create a separate KMACHINE, that is
>> just more to manage and maintain (especially if something changes in
>> meta-xilinx). Using KERNEL_FEATURES to enable things for your machine
>> is probably a simpler option.
>
> KERNEL_FEATURES was the one thing I didn't know about. That's perfect,
> thanks!
>
>
>> Sort of depends on your goals, is your goal to overlay the
>> linux-xlnx/yocto kernels with additional configuration? if so than
>> using the meta directories works well. However if it is just a small
>> set of configs you may be able to get away with just adding the files
>> to the SRC_URI, see the meta-virtualization layer for an example of
>> that: http://git.yoctoproject.org/cgit/cgit.cgi/meta-virtualization/tree/recipes-kernel/linux
>
> I tried to do the way it's done in meta-virtualization but I ran into an
> error during do_patch:
>
>> ERROR. Could not locate meta series for zynq
>
> I added all .scc files to SRC_URI and the folder where the files are
> located to FILESEXTRAPATHS of course. A check with bitbake -e looked
> okay and bitbake didn't complain that it couldn't find the listed files.
> I listed all .scc-files I wanted to add in the KERNEL_FEATURES variable
> as you suggested.

So if you are just using standalone .scc/.cfg files once you add it to
the SRC_URI it will be added to the config setup. KERNEL_FEATURES only
comes into play with the kmeta directories. So you don't need to have
KERNEL_FEATURES set for the standalone .scc files. Sorry I should have
mentioned that.

Also for reference you can use machineoverrides to conditionally add
the .scc standalone files to the SRC_URI.

>
> After putting everything (the .scc and .cfg-files) into a dedicated
> subdirectory and adding the whole directory as a kmeta directory to
> SRC_URI it magically worked. I have no idea how to debug this to be honest.

Check the logs of do_kernel_configme and do_kernel_configcheck. They
should be helpful in regards to where things go wrong with regards to
the kmeta config merging.

There is also the output in the
linux-<machine>-standard-build/source/.kernel-meta/meta-series of the
kernels work directory. This will give you the details as to what
scc/cfgs where actually consumed and used to generate the output.

Regards,
Nathan

>
> It looks like bitbake fails as soon as I add an .scc-file to SRC_URI. If
> they are added via a kmeta-directory it seems to work fine.
> I didn't build a full image and tried it yet, but the generated kernel
> config looks fine. It's still compiling - I did a clean build because of
> the error...
>
> Regards,
> - Andy
>