Re:Arm Announces Client CPU Roadmap For Laptops
by 0xakhil on Friday August 17, 2018 @12:26PM
(#17783952)
I am not sure if this is correct. There are related instructions like 'smc' that helps to switch to secure world.
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Re:Arm Announces Client CPU Roadmap For Laptops
by monocasa on Friday August 17, 2018 @12:31PM
(#17783990)
OK, so there's the one instruction to do a system call that hits secure mode. It's equivalent to svc or hvc, but hits EL3 (secure mode) rather than EL2 (hypervisor mode) or EL1 (supervisor mode).
It's very very different than the dozen or so instructions to setup TXT or SGX that sits off to the side of the main OS rather than running like a super hypervisor. If you're going to compare it to something, it's way more like SMM on x86.
Source: I've ported a kernel to EL3 (secure mode).