Kernel Upgrade

Currently the jetson nano image is on version 4.9 but i want to use hardware that needs a newer version.
my only solution is to backport but this then breaks other hardware i want to use which is not ideal.

i have tried building a new kernel but the nano fails to boot.

is there a guide to building a kernel for the nano and/or a repository where the public can have access to the source currently being tested?

Please refer to kernel customization section from L4T doc: