[seL4] How would you approach supporting a new processor architecture?

Hello! I’m writing to ask how someone would approach porting seL4 to a new CPU architecture. For example, ppc64le/IBM Power, since those systems can be run with limited or no black box firmware blobs, they could offer stronger security under seL4 since you can audit or replace the platform firmware in many cases. There’s even an OEM manufacturing Power9 systems with this in mind. That said, I know supporting a new architecture is not trivial. New platform code would have to be written and verified, and existing userspace code for Arm and x86-64 may have to be adjusted. How does one approach something like this? Is it feasible for someone less familiar with seL4’s internals to get something quick and dirty running as a proof of concept?