Add files to introduce a memory clearing framework.
Introduce Kconfig PLATFORM_HAS_DRAM_CLEAR that is to be selected by
platforms, that are able to clear all DRAM.
Introduce Kconfig SECURITY_CLEAR_DRAM_ON_REGULAR_BOOT that is user
selectable to always clear DRAM on non S3 boot.
The function security_clear_dram_request tells the calling platform when
to wipe all DRAM. Will be extended by TEE frameworks.
Add Documentation for the new security API.
Change-Id: Ifba25bfdd1057049f5cbae8968501bd9be487110
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31548
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Reviewed-by: Christian Walter <christian.walter@9elements.com>
Patrick Rudolph