[android-kernel] Porting android kernel to new version of android

[Au]

So I've worked with building existing kernels, but never have I tried to
port a kernel to a new version of android. I've started to gain an interest
in porting kernels, but could not find anywhere a proper guide to assist
me. Would I have to merge the changes of the new common android kernel with
my existing kernel sources? idk. If somebody could point me in the correct
direction, that would be a great!