arm64: enforce x1|x2|x3 == 0 upon kernel entry as per boot protocol
authorArd Biesheuvel <ard.biesheuvel@linaro.org>
Tue, 17 Mar 2015 09:55:12 +0000 (10:55 +0100)
committerWill Deacon <will.deacon@arm.com>
Thu, 19 Mar 2015 19:46:02 +0000 (19:46 +0000)
commitda9c177de88679c2948dc9a5e2325b0dff4677b9
tree1ef1c5f3698aea6230899127fb1583ab55faa53c
parent6f4d57fa7021efbf135cfa068d56bc5035edffa1
arm64: enforce x1|x2|x3 == 0 upon kernel entry as per boot protocol

According to the arm64 boot protocol, registers x1 to x3 should be
zero upon kernel entry, and non-zero values are reserved for future
use. This future use is going to be problematic if we never enforce
the current rules, so start enforcing them now, by emitting a warning
if non-zero values are detected.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/kernel/head.S
arch/arm64/kernel/setup.c