[xenadu02]

Where are you people getting this from? This is not accurate. You can in fact downgrade security from recovery OS.

ARM doesn't have a generic platform like PC but I'm sure someone will figure out how the device tree works if they haven't already.

[cesarb]

ARM does have a generic platform like the PC, it's the BSA (https://developer.arm.com/documentation/den0094/a).

[xenadu02]

LOL, I should have known someone would try to "well akshually" me.

The BSA/SBS is relatively new as far as I'm aware. The server version was released in 2014, the same year as the iPhone 6 which was already using Apple SOCs.

I don't know when the client version was released but fairly recently AFAIK. I don't know of any systems shipping based on it.

Most ARM systems are using device trees and their own custom slate of devices.

So I should amend my comment I suppose: no one is using any kind of "Standard ARM PC" definition in any quantity, and I'm not sure we should bring over UEFI or ACPI when device trees have been working well so far.

Nevertheless as I noted I'm sure enterprising hackers will figure out how to do it. If you downgrade security the SEP will sign whatever "kernel blob" you like and the system will load and jump to it at boot. Technically that isn't even required - a kext could pause all CPUs, set the correct registers, and jump to a completely different OS if you were really determined.