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It might be patchable, even though it's in ROM. The ARM chip I've been working on has a mechanism to change a few words in ROM by blowing fuses... basically, be
by morcheeba 7y ago
It might be patchable, even though it's in ROM. The ARM chip I've been working on has a mechanism to change a few words in ROM by blowing fuses... basically, between the ROM and the CPU sits a device that compares addresses and if matches what's found in the fuses, will replace the data being read. Since it doesn't have to be fast (since ROM code is only used at boot and there isn't a lot of it), they can slow down memory access to get more security.
- floatboth 7y agoApple would've very likely patched it a long time ago if it was patchable, since the newest devices' ROMs don't have the bugs anymore. Having a completely 100% untouchable ROM is very valuable. Yes, this kind of exploit being permanent is the downside, but then they don't have to worry about the modification fuses being misused in any way ever.