> How could they do that?

iBoot? Asahi needs iBoot to boot third-party volumes for Linux to run properly. Apple controls iBoot; if they burn an eFuse and disable third-party volumes in a "Security" update, Asahi cannot fight back.

You cannot boot macOS with an unsigned iBoot firmware, so writing your own bootloader isn't an option. If a fuse is burned, you also cannot downgrade to older firmwares. The entire system is designed to give Apple the ability to disable other OSes in a macOS update if they ever decided to.

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simonh 2 hours ago | parent [-]

iBoot firmware exists and is already in our hands.

Any manufacturer could put an eFuse in any of their hardware and lock it. No hardware can be proven not to have such exploits. That's the first point marcan makes in that post.

	▲	bigyabai 43 minutes ago \| parent [-]
		> Any manufacturer could put an eFuse in any of their hardware and lock it. This is my point too, though. Do we trust Apple to not burn a hardware fuse if their community one-ups them? They've already done it on iPad and iPhone hardware when users find a boot ROM exploit. All that they'd need to do is push an update for "security" purposes, and then the new boot flow could refuse to boot into unsigned volumes or deny running unsigned bootloaders. There would be no way to downgrade. This is basic ARM security architecture stuff, I'm a little shocked that people can't imagine how this type of lockout is possible. There are tons of commodity ARM boards that are effectively bricked and eFused to user-hostile security epochs.