tree ffefc51cc344409cede664cc45ba79a7df03aad1
parent 1926900454166df3de18a1fa584e79dab8a48d75
author Nico Huber <nico.h@gmx.de> 1759874282 +0000
committer Nico Huber <nico.h@gmx.de> 1770668506 +0000

amd: Fall back to reading rom3 range in case of ROM Armor

AMD is pushing ROM Armor forward, which leaves the SPI handling to
the PSP and only a mailbox interface (guarded by SMM) for the main
CPU. With the current ROM Armor 3, there is no opt-out in the BIOS
setup anymore.

Only access left for the main CPU is the read-only memory mapping.
We make this available when active ROM Armor is detected (SPI BAR
register reads all ff). Probing of the flash size is peculiar, we
can only try to guess it when memory contents look repetitive.

To not pollute the `amd_spi100` driver, we start a new one.

Story: https://icon.sourcearcade.org/posts/amd_firmware_reading/
Change-Id: Ib4866084fe80853fd66501176dbc6b766750062f
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/350