soc/amd/picasso: Enable APOB/MRC training data cache

Picasso doesn't really make use of the common mrc_cache driver because
of the PSP/ABL requirements for APOB NV data. The APOB NV data
gets consumed by PSP/ABLs before x86 comes out of reset. Hence, we cannot
really add any metadata to this saved data or use multiple slots as
done by the default MRC cache driver
(CACHE_MRC_SETTINGS). Additionally, FSP-M requires access to this APOB
NV data which coreboot needs to pass in from different locations
depending upon boot mode:
1. Non-S3 boot: PSP/ABLs store APOB NV data in DRAM at predetermined
location which is present in BIOS directory table.
2. S3 boot: PSP/ABLs do not store APOB NV data in DRAM.

Thus, coreboot needs to set FSP-M UPD NvsBufferPtr as the DRAM
location in non-S3 boot and the address of RW_MRC_CACHE on SPI flash
in case of S3 resume.

This change enables MRC cache support in Picasso in order to meet the
above requirements.
1. NvsBufferPtr is set based on boot mode.
2. APOB NV data is not stashed to CBMEM. Instead it is written right
away to SPI flash in romstage.

BUG=b:155990176

Change-Id: I8661a4cf2d34502967e936bf22a13f6f1b88e544
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42107
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

0 files changed, 0 insertions, 0 deletions