Comment by zer0zzz
6 hours ago
1) Intel and AMD help to implement support in Linux before their chips even ship. Actually a sanitized version of the Intel graphics ISA bspec is actually available to the OSS community too.
Apple on the other hand provides no support. The one nice thing they did do is allow their bootloader to boot non-apple signed OSes. They do not do this on iPhones, iPads, Apple TVs, Watches, or homepods btw.
2) The GPU ISA changes drastically and often. Its not entirely uncommon for the entire instruction set to change entirely within one generation. Every change to the ISA would require an entire round of new reverse engineering (I suspect, ive never reversed).
I do wonder why Apple chooses not to lock down the Mac to just Mac OS like all their other hardware? I'm sure the sales from people who intend to run something other than MacOS look like a floating-point error on the scales Apple operates.
I don't think it is possible to have a locked down development machine. You have to be able to run arbitrary code on a development machine so they can never lock it down like iOS is.
There are plenty of other ways they can be less open and hackable than Linux but it can never get to the point of the iPhone.
You replied to your own question. Locking down the system for 3 users worldwide and making sure it stays locked is not worth the effort.
Just not publishing the specs is enough to delay so much the effort that those machines are out of warranty and have depreciated so much by the time they are supported that they aren't competitors to the mac ecosystem anymore.
They don't because it's a floating-point error now. But with the continued enshitification of MacOS, it likely won't be in the future, and they just may lock it down. But being so hostile to the hacking community would do more harm than good, so I doubt that they would do so even if Linux use on Macs grew to >1%.