arm64: boot protocol documentation update for GICv3

Linux has some requirements that must be satisfied in order to boot
on a system built with a GICv3.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Marc Zyngier 2013-11-28 18:24:58 +00:00 committed by Christoffer Dall
parent 96f68023bf
commit 63f8344cb4

View file

@ -141,6 +141,14 @@ Before jumping into the kernel, the following conditions must be met:
the kernel image will be entered must be initialised by software at a
higher exception level to prevent execution in an UNKNOWN state.
For systems with a GICv3 interrupt controller:
- If EL3 is present:
ICC_SRE_EL3.Enable (bit 3) must be initialiased to 0b1.
ICC_SRE_EL3.SRE (bit 0) must be initialised to 0b1.
- If the kernel is entered at EL1:
ICC.SRE_EL2.Enable (bit 3) must be initialised to 0b1
ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b1.
The requirements described above for CPU mode, caches, MMUs, architected
timers, coherency and system registers apply to all CPUs. All CPUs must
enter the kernel in the same exception level.