vboot: add vbnv flash driver

this adds a driver for vboot to read and write nvdata in spi flash.
it's assumed that flash contents are erased to 1-bits and write
operations can only change 1-bits to 0-bits.

when all nvram space is used, the driver will erase the whole block
and start the next write from the beginning.

TEST=Built for cosmos.

Change-Id: I40858f847151aa0770e1101e905476d270550f60
Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Original-Commit-Id: 09713828b7b0cabd13a08de3f34e32bc4dbef4a4
Original-Change-Id: Ia9049f342b21fa4c289cb7b9254ab89ec1ef1699
Original-Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/226525
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9229
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed