Add an SVC command to get the previous boot status. If there is any
pre-x86 boot failure in the previous boot cycle, PSP stores it in warm
reset persistent register and triggers a warm reset. PSP verstage on the
subsequent boot gets the previous boot status and reports any failure to
the vboot before a FW slot is selected.
BUG=b:242825052
TEST=Build Skyrim BIOS image and boot to OS in Skyrim. Trigger a failure
scenario by corrupting certain firmware blobs and observe that PSP
reports the failure boot status. On a normal boot, observed that PSP
reports successful boot.
Change-Id: I440deee560b72c80491bfdd7fda38a1c3a4299e5
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70381
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
7b49d1b198