> I can't find anything in the guide from a quick skim, but I'd suspect the code is on a ROM chip or is somehow prevented from an upgrade without an unlock?
This is the big unanswered question. I suspect the same, but so far have not been able to find anything that actually says so. The code is not in ROM, as it can be updated, but it could wipe data if updated without an unlock. But I can't find anything saying whether it actually is. The mere fact that it's possible isn't enough, and their silence is a bit odd.
Seems like it'd be a pretty huge oversight if that vector were open, but I agree with you that it's not very confidence-inspiring if nothing about this is out there.
Depends on your threat model. It's possible that the Secure Enclave was just intended to be a defense in depth against malware and common criminals, not something that could keep Apple themselves out. If so, I'm sure they're re-evaluating that now.
This is the big unanswered question. I suspect the same, but so far have not been able to find anything that actually says so. The code is not in ROM, as it can be updated, but it could wipe data if updated without an unlock. But I can't find anything saying whether it actually is. The mere fact that it's possible isn't enough, and their silence is a bit odd.