[meta-xilinx] US+ MPSoC Default Kernel Config vs Kernel Meta Data

[Peter Smith]

Thanks Nathan that’s now 100% clear for me.

> On 16 Oct 2017, at 18:20, Nathan Rossi <nathan at nathanrossi.com> wrote:
> 
> On 17 October 2017 at 02:44, Peter Smith <salerio at gmail.com> wrote:
>> A question for someone with more knowledge than me. How do the Xilinx
>> default config for zynqmp i.e. KBUILD_DEFCONFIG-zynqmp =
>> “xilinx_zynqmp_defconfig” and the kernel meta data contained in the
>> recipes-kernel/linux/config directory interact? Is one added after the
>> other, does one override the other, you get the idea. Thanks Peter
> 
> Using KBUILD_DEFCONFIG with kernels that include/inherit linux-yocto
> (such as linux-xlnx) is the same behavior as linux-yocto supports by
> providing a 'defconfig' file via SRC_URI. This essentially treats the
> defconfig as the first config fragment, the kmeta (the metadata in
> linux/config/xilinx-*) is applied after and can override what is set
> in the defconfig.
> 
> Currently with linux-xlnx, KMACHINE is also setup which causes the
> inclusion of zynqmp-standard.scc. This layers on top the defconfig
> with config fragments that are used for zynq/microblaze targets, which
> are equivalent to the xilinx*defconfig but re-implemented as
> fragments. This does mean that for zynqmp there is duplication of
> config between the defconfig and the fragments, but there is no
> removal of config in the fragments of meta-xilinx.
> 
> For linux-xlnx this is to change slightly with the planned merge of
> this series (https://lists.yoctoproject.org/pipermail/meta-xilinx/2017-October/003183.html).
> Which makes linux-xlnx configured only by KBUILD_DEFCONFIG and any
> features that are setup in KERNEL_FEATURES/SRC_URI, and does not use
> or set any KMACHINE.
> 
> Regards,
> Nathan