I'm developing a distro for the LX2160ardb board using the Yocto SDK from NXP (per the thread Are there instructions to build images from Yocto for LX2160A RDB? ).
I need to customize the kernel for this distro. I have attempted to modify the kernel configuration using the the methods in the Yocto documentation. Specifically, I have created a bbappend to supply a defconfig file, as well as creating a cfg (from the bitbake diffconfig command). Neither approach works when starting a kernel build from a clean (bitbake virtual/kernel -c cleanall followed by bitbake virtual/kernel).
The kernel configuration works if I build an image (bitbake fsl-image-networking -> bitbake virtual/kernel -c menuconfig -> bitbake fsl-image-networking). However, I need to have the Yocto build fully automated from first principles, aka. checking out all layers from scratch and doing an image build.
Upon further investigation, the recipe linux-qoriq_4.14.bb or linux-qoriq_4.19.bb in the meta-freescale/recipes-kernel/linux layer seems to intercept the kernel config process. Within these two recipes, there is a function do_merge_delta_config that assembles a defconfig. This task is then inserted into the Yocto task stack via addtask merge_delta_config before do_preconfigure after do_patch.
I still have the need to modify the kernel, however since the freescale layer deviates from the Yocto norm, I don't know the best way to patch my kernel customizations into the build process. Commenting out the addtask line in the recipe works, but again I need to build a distro from a fresh clone of all layers.
What is the recommended approach to modify the kernel configuration when using the freescale layers for the QorIQ?