Howard has written a really nice summary there. Interesting stuff.
It’s a bit of a shame the new M1 Macs don’t support a real Internet Recovery mode anymore. If your M1’s internal SSD fails you’re obviously done, but I would have liked to think that in case it was just corrupted, you’d be able to set it up from scratch (including disk1 and disk2 containers) using Internet Recovery. Howard’s article makes it quite clear that won’t work and instead you’d have to go into DFU mode and use Configurator 2.
It will be interesting to see how Apple treats backwards compatibility now. It’s no longer obvious an M1 Mac will be able to boot the macOS version it shipped with if you’ve in the meantime run more modern macOS versions. For that to work, they have to explicitly allow for it in the more modern variants of iSC and 1TR that you’ll have had installed in the meantime. Depending on how Apple does this, this could be quite a change from what we’ve become accustomed to on the Mac (you can always boot as old as whatever it shipped with).
Well maybe there is a fallback in there after all. Not quite full Internet Recovery, but there is a a second recovery partition in there. 1TR is actually more like 2 True Recovery.
Double-press and hold power on an M1 Mac. Done.
A very interesting find. I think this will protect against a corrupt Recovery container, but I suspect (and will love the be proved wrong) that a valid ISC container will still need to be present. If ISC gets trashed, Configurator may still be required for recovery.