security/vboot: Update vboot context with slot B absence

coreboot offers two vboot schemes VBOOT_SLOTS_RW_A and
VBOOT_SLOTS_RW_AB. When VBOOT_SLOTS_RW_AB is not selected then the
resulting image is rather not expected to have the FW_MAIN_B FMAP
region. When only RW_A region is used, vboot does additional full_reset
cycles to try RW_B, even though it does not exist / the build was not
configured for two RW partitions. To avoid it, a new vboot context
flag has been introduced, VB2_CONTEXT_SLOT_A_ONLY, which can be set
right after context initialization to inform vboot about absence of
slot B. This will result in less full_reset cycles when vboot runs
out of available slots and cause vboot to switch to recovery mode
faster.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Change-Id: Ie123881a2f9f766ae65e4ac7c36bc2a8fce8d100
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75462
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions