[meta-fsl-ppc] How to change the kernel config?

[Joerg Albert <jal2@gmx.de>]

Hi,

I'm quite a newbie to Yocto, sorry if this is a dumb question.

I want to tweak the kernel config for P2041RDB with Freescale SDK 1.6 using a separate custom layer containing
a recipe-kernel/linux/linux-qoriq-sdk_3.12.bbappend. The layer config seems to be fine,

bitbake-layers show-appends

recognizes it.

I've first tried to to use a configuration fragment (as described in the Yocto kernel documentation in chapter 2.2.3), but
this seems to fail as the base recipe does not inherit linux-yocto, but kernel.

Putting a files/defconfig there with a line like

SRC_URI += "files://defconfig"

didn't work either - I guess due to the special handling of .config via KERNEL_DEFCONFIG in linux-qoriq-sdk.inc in meta-fsl-ppc.

At last I tried

DELTA_KERNEL_DEFCONFIG += "${THISDIR}/files/my_incremental_config_change"

but this searches the files in meta-fsl-ppc/recipes-kernel/linux/files (or inside the source code tree of the kernel), while I'd
prefer to have it inside my custom layer.

What is the easiest way to have a kernel config change (incremental preferred) with all files inside a custom layer?

Cheers,
Joerg