chromeos: Add option to back up VBNV CMOS into flash

This adds a new kconfig option that will back up the VBNV data
from CMOS to flash, and restore it if the CMOS data is invalid
during boot.

This allows special flags to not get lost when power is lost,
RTC reset is triggered, or CMOS is corrupted.

BUG=chrome-os-partner:47915
BRANCH=glados
TEST=manually tested on chell:
1-boot and run "enable_dev_usb_boot"
2-reboot and check that it is enabled with crossystem
3-run "mosys nvram clear"
4-reboot and check that it is still enabled

Change-Id: I38103d100117da34471734a6dd31eb7058735c12
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 8a356e616c6885d5ae3b776691929675d48a28f9
Original-Change-Id: I06e7ddff7b272e579c704914a0cf8cc14d6994e8
Original-Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/324122
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/13600
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

0 files changed, 0 insertions, 0 deletions