./compile.sh CREATE_PATCHES="yes"
change sources when asked and a patch will be created / updated. Once done, copy that patch to the patck/kernel/sunxi64-edge/ folder and pay attention to the patch executing order. Hint - if you need that patch is executed last, add higher number or simply xx in front of the patch filename.
For adding an overlay, check this patch: https://github.com/armbian/build/blob/master/patch/kernel/archive/sunxi-5.15/general-sunxi-overlays.patch
