All Apple Silicon machine owners are licensed to use macOS (and all of its components), among other things, because it is actually a critical part of system firmware (as part of system recovery; the machine boot picker is itself macOS even).

Apple provides restore images for this purpose (downloadable without any authentication). This is how the installer works, so we don't have to redistribute any firmware ourselves. Redistribution is the usual thorny firmware problem; since we don't have to do that, we're in a pretty good position.

Whether Apple's EULA applies to macOS obtained in this way, without actually going through a normal boot for that instance and thus the click-through EULA, is legally unclear. That said, here's a quick analysis:

2A says you can only install and run a single copy of the software. That might seem to imply that you wouldn't be able to dual-boot macOS and Asahi Linux, but this clause is pretty dumb. By design, all of these machines with one instance of macOS have at least two copies of part of the software: the recovery image - is that a violation? What about the fact that the bootability process creates a copy of all system firmware? You end up with 4+ copies of some components. What about installing macOS multiple times? Multiple versions of macOS? Do APFS CoW clones count as copies? If so that's another two copies of the recovery image. If they don't, can we just CoW clone stuff from the currently installed macOS version within the same container instead of doing a from-scratch install? Once Apple's updater breaks the CoW link, does that mean they are causing you to violate the EULA at that point? These are all things Apple obviously intended for people to do with these machines, regardless of what the lawyers say, so I don't think we have to worry too much about it. Legal texts are often completely at odds with the technical realities involved, and in the end nobody cares.

2M explicitly allows you to replace the Open Source components of macOS with your own version. This is exactly what m1n1 is: it is a replacement for xnu, the open source macOS kernel. So this clause explicitly puts at least our original full-fat macOS install process in the clear. The clause also says their warranty does not cover damage caused by such modifications, but does not say your warranty is void by merely doing so (so they'd have to prove any damage was caused by it).

2N says no reverse engineering, but you don't care about that, we do. I'm pretty confident I'm not going to get a C&D from Apple's lawyers for working on Asahi Linux, and if I do, I know how to defend myself and what organizations can help with that. It would be terribly bad PR for them to do that.

4A says you can transfer your Apple software, but 4B says you can't do that if you've modified it under 2M. That might mean that, on paper, you can't give away or sell a Mac that has Asahi Linux installed, without first uninstalling the bootloader and having the next owner reinstall it. Again though, this is a silly technicality. What Apple means is they don't want you patching macOS and distributing it separately. They also say the macOS components are a bundle and cannot be distributed separately, but our installer doesn't distribute anything, it pulls specific components from Apple themselves, which they are distributing.

4C says that you may only use copies made available for restorative purposes for those purposes and may not be resold or transferred. That might put our usage of ipsw restore images in the installer out of compliance, though the "restorative purposes" thing is a bit unclear. Does it count as "restoring" Apple's boot components into a blank OS partition? Obviously we are not reselling or transferring anything, so that part is not an issue.

This is an EULA, and to what extent these clauses are legally enforceable is of course unclear. We aren't doing the big copyright no-no of redistribution, and Apple themselves provide the software for free download, and it is a fact that every Mac user is licensed to use it. So in practice it would be quite questionable to try to go after people for technicalities here.

The better question is whether Apple's lawyers will care, and I'm pretty sure the answer is no. The EULA is there to give them legal ammo against companies trying to do things like provide virtual macOS as a service or installing it on non-Apple machines; they don't really care what end-users do (they don't even care about hackintoshes as long as you aren't selling them, which is a blatant EULA violation). The general idea of running Linux with Apple's firmware is completely kosher per 2M (if done on a single macOS install, e.g. just replacing xnu with m1n1 without a separate OS instance), so there is no legal basis for Apple to block our project entirely. It would be extremely silly if they went after our users to block our specific install process just to annoy them or get them to replace macOS with Linux instead of dual-booting, and it would also put in jeopardy things that regular macOS developers do, like having multiple OS installs.