> _clearly_ spent a lot of time and resources to make third-party OSes viable on Apple Sillicon Macs.

This actually isn't clear to me -- can you explain? Besides keeping an open bootloader [0], I'm not aware of any affirmative actions Apple has taken.

[0]: https://github.com/AsahiLinux/docs/wiki/Open-OS-Ecosystem-on...

The open bootloader didn't magically appear one night in Apple's git repository.

It boots in a notably different way than iOS machines do, and has some (AFAICT) pretty unique capabilities, including a fully-verified signed-boot of macOS partitions, while allowing third-party kernels at the same time.

Asahi's "Introduction to Apple Silicon" [0], and specifically "Security modes, Boot Policies, and machine ownership" paragraph outlines some of that, Apple's "Platform Security" [1] whitepaper does too.

Asahi's docs also explicitly state the same thing [2].

If you still don't think that shows significant amount of work and care were put into deliberately allowing third-party OS's to work on those machines, I don't think I can convince you otherwise.

[0]: https://github.com/AsahiLinux/docs/wiki/Introduction-to-Appl...

[1]: https://support.apple.com/guide/security/welcome/web

[2]: https://github.com/AsahiLinux/docs/wiki/Apple-Platform-Secur...

There is also no precedent for Apple making any kind of pro-active design choices around future regulation. They clearly are the kind of company that does whats best for them and when asked to change, nudges in that direction, and then moves on. This is in the DNA from the top down. It would certainly be weird to make the decision about third-party OSes be about that.

They did. Which is why it’s so baffling that they didn’t document any of this stuff. 5 minutes of documentation by apple engineers on the boot process or GPU would have saved 5 hours of reverse engineering work by the Asahi Linux team.

Seems to me like they can’t decide whether they want Linux on their hardware or not. I bet different people in the org are pulling in different directions.

It’s not baffling at all. Opening the boot chain is work, but making presentable documentation is a lot more. It’s not 5 minutes of work: it’s years of checking the licensing on everything, designing stable APIs that are fit to publish, supporting them, having engineers working on this. You can’t just throw your internal “G13G scheduling pipeline” docs over the wall.

> I can’t imagine any reasonable argument that would make Apple be a target for an anti-trust action for _Macs_.

Why can't the same "there is no OS except iOS allowed on iPhones" argument be applied here? If the only os that boots on a macbook is macOS, that's starting to smell like anti-competitive behavior the same way that only app store approved apps can run on iOS is anti-competitive.

Because the market share is order of magnitude smaller.