It seems like this is a bug, apple went through the trouble to allow something like asahi to be possible in the first place. I doubt they're purposely trying to break it.
It seems like this is a bug, apple went through the trouble to allow something like asahi to be possible in the first place. I doubt they're purposely trying to break it.
Apple designed a bootloader for Apple Silicon Macs that allows you to run an unsigned OS without degrading security when you boot into MacOS. This wasn't an accident.
Macs have always allowed you to run another OS.
iDevices have always had a locked bootloader.
People shouldn't confuse the two.
M series macs are weird tho, yes the bootloader allows it but absolutely no documentation on the hardware, drivers etc. Can't help but to think the goal of this wasn't to actually allow third-party OSes, but for development purposes(and ye they could hide the feature behind apple account with paid dev license) or anti-anti-trust measures à-la Google with Firefox: in front of a jury of normal people they can simply say "look there's these nerds making Asahi" the same way "look we're not a monopoly Firefox has .2% market share".
> M series macs are weird
More weird than the opaque Management Engines on Intel or AMD chips that can take full control of your system at any time that you have no control over?
> Can't help but to think the goal of this wasn't to actually allow third-party OSes
Apple has explicitly stated that allowing third party OSes is exactly the purpose of the new bootloader.
I don't know about Intel ME but AMD PSP is basically the equivalent of Apple's Secure Enclave, so there's that.
Yes, more weird than that. x86 PCs have fairly standardised boot and autoconfiguration (UEFI and ACPI). ARM based systems, including the Apple M series, don't. You just have to know what's there (device trees), and Apple isn't going to tell you. Hence why it's difficult to make another OS run on it, because you first need to find out what hardware's even there, and how to talk to it. It's initialised by Apple before iBoot runs, sure, but you don't even know what it is, so good luck writing a driver for it.
The Intel ME / AMD PSP are creepy, and probably a security risk to the device owner, but they're not weird, you can run an OS without even knowing they're there, and they like it that way.
The design of the exposed mechanism is explicitly about booting unsigned versions of MacOS. There is zero support for booting anything else, but no enforcement that it must be MacOS.
However, apple's justification for exposing this mechanism to users appears to explicitly include "booting linux" even if the mechanism has zero explicit support for booting linux.
I think they are wary about macOS becoming a designated DMA gatekeeper, it would certainly be very close to the user and income thresholds.
And if Apple were going to change their mind and try to block linux, they would intentionally modify the bootloader to remove that functionality, not break the boot picker.
If they allowed something similar on iphones, I'd switch to an iPhone the day an alternate os worked well enough for daily use.
Such bugs have happened and been reported before. Asahi exercises "raw boot" facilities that just don't get all that much attention in any other context.
(removed)
If the happy path disappears, the not-so-happy path will be taken to allow for booting custom kernels, one that will likely rely on turning the some or a lot of the RE energy towards breaking the Secure Enclave, the bootloader, and so on. Apple practically laid the red carpet out to avoid people trying to crack the parts of the hardware/software chain-of-trust they would really rather not have cracked. A similar strategy helped keep the Xbox One un-pwned for over a decade (running homebrew was allowed in a specific mode). It is doubtful Apple's legal department isn't aware of the value of the current software strategy.
So isn't that just purely security by obscurity then? Would they not rather have someone publicly break it instead of selling a zero day?
No, if their lawyers want it gone, Apple will just update the bootloader to reject local signing keys.
The actual problem was that Apple has an undocumented APFS key for if a volume is bootable, which Asahi wasn't setting and Apple wasn't checking, but now they do, so they do.