[yocto] [meta-raspberrypi] how to apply custom kernel configuration?

[Andrei Gherzan]

On Sat, May 6, 2017 at 6:14 PM, Khem Raj <raj.khem at gmail.com> wrote:
> On Sat, May 6, 2017 at 9:45 AM, Andrea Galbusera <gizero at gmail.com> wrote:
>> Hi!
>>
>> I was wondering how to apply some extra kernel configuration from a custom
>> layer via a bbappend. I know that with meta-raspberrypi there exist some
>> variables you can define in local.conf that will drive how the kernel is
>> configured: but what about some very specific device driver nobody than me
>> is interest in? To me it seems it doesn't deserve a dedicated global oe
>> variable.
>>
>> Some investigation showed this topic already came up on the list from time
>> to time in the past (most recently in [1]). To me it looks like there is
>> some common desire to get rid of the current "magic" carried out by
>> linux-rpi.inc by moving the linux-raspberrypi recipes into the configuration
>> fragments style.
>>
>> In the short term, my question are: how do you guys manage to add your
>> custom kernel configurations? Do you rely on full blown static defconfigs?
>> Have you found any reliable way to do "differential" configurations with the
>> current state of metadata?
>>
>> In a longer term, I'd really like to help moving towards supporting
>> configuration fragments for linux-raspberrypi, but I suspect it'd be a too
>> much hard task for my current understanding of the whole kernel
>> configuration workflow. Do you know of anyone already working on this or
>> does anyone have a clear idea of what is needed to get the work done? Some
>> times ago I tried to resurrect [2], but with no luck, probably due to some
>> changes that happened in the linux-yocto files in the meanwhile.
>>
>> Comments from gurus are welcome! ;-)
>
> I have been hinting at using yocto kernel tooling. Idea is worth a pull request
> care sending one ?

I'm not using config fragments myself but I was under the impression
that we do support it.

--
Andrei Gherzan