I don't understand why you think Apple specific components matter, surely Linux developers will ignore those and focus on the cpu side.
I don't see 2a happening, and let's hope for 1a and time.
Surely the Linux kernel does not support these things now, but there's only baseless speculation that Apple would actively lock this down.
> They are slowly but surely moving towards not being apple to run anything not Apple on OSX as well.
I would argue that both of these statements are completely baseless, and the second is actually actively argued against by Apple.
I'll be the first to say that their handling of iOS things is horrible, and I would buy iPhones and iPads if they were a more open platform, but the world is more complicated than "Apple is evil" and their handling of iOS has no bearing on the Mac.
In my view you can only believe Apple will lock down the Mac if you somehow view them as an irrational ideological opponent, not simply a company that wants to make money by selling computers. Since you say you don't care what Apple themselves say towards this, I can't escape the impression that you might actually already view them in this way. If so, there's not much we can talk about.
I really would love nothing more then buy the new Apple Arm Macbook Pro but I can't risk investing in this ecosystem when, to me, it's quite obvious where Apple stands on this.
> I rather watch their actions.
And which actions are those? Gatekeeper and the Apple T2 are not enough to make the Mac not an "open computing platform", let alone something close to iOS. I'd argue they're not even on the way there, just like Windows SmartScreen isn't on the way there. And note that the T2 is even gone from Apple Silicon Macs.
Apple deserves all the added scrutiny in this area because of their attitude on iOS [1]. But there's absolutely no reason to believe that Apple's direction towards locking down Macs is either "clear" or "inevitable" in my view.
[1]: There are some identifiable explanations as to why iOS is so locked down whereas the Mac isn't, but let's talk about that some other time.
If everything works exactly like iOS you save $$$$$$$, added benefits you can charge enterprise licensing fees to get access to your sdks and dev tools. And if you have e.g. a luxury market cornered you can command those sorts of prices.
This is exactly Apple's playbook, I don't know why anyone would expect them to do anything different...
Not as the primary boot OS, perhaps, but it will work under virtualization. The M1 chip supports virtualization, and Apple has a new hypervisor API in Big Sur:
1b and device drivers seem to me like the biggest obstacles.
As far as I know there Linux driver support for Intel Macs is abysmal, due to lack of support from Apple.
I would be shocked if ARM Macs, which will probably be even more locked down, were more open somehow.
And partially because Apple built their own silicon, which means there could be secret instructions or instructions that work slightly differently than expected for ARM. I don't know how true this is for the M1 but it's been one of many issues holding back non-Apple compilers and Linux on Apple mobile devices. Having the M1 on a real desktop computer with deep debugging tools may mean we can fuzz and fully characterize the M1, which was harder to do on iPhones.
For macOS, the support revolves around Xcode. Cross-compilation support is Apple-specific and won't benefit Linux. CPU architecture is abstracted away in macOS as much as possible, so average developers won't think much about ARM support.
Where Apple wants developers to tune for M1 specifically, is their proprietary frameworks for ML acceleration and Metal, which don't benefit anyone but Apple.
At best there may be some halo effect from proving that ARM can be as fast as "real" desktop CPUs, and it's not just the low-end slow Qualcomm chips. That might legitimize running ARM on servers, but Pi is neither high-end desktop nor a server platform.