Comment by misswaterfairy

It's worth watching the 39C3 talk about porting Linux to Apple Silicon earlier this year.

https://media.ccc.de/v/39c3-asahi-linux-porting-linux-to-app...

The jist is that Apple don't want to prevent you from running your own bootable code on a Mac (which isn't true for iPhone and iPad, sadly), as long as you don't compromise the security of Apple's bootloader, code, etc.