[M] Change in coreboot[master]: soc/intel/cse_lite: Back up PSR data during CSE FW downgrade

[Krishna P Bhat D (Code Review)]

Attention is currently required from: Jérémy Compostella, Paul Menzel, Sridhar Siricilla.

Krishna P Bhat D has uploaded a new patch set (#43) to the change originally created by Anil Kumar K. ( https://review.coreboot.org/c/coreboot/+/74577?usp=email )

The following approvals got outdated and were removed:
Verified+1 by build bot (Jenkins)

Change subject: soc/intel/cse_lite: Back up PSR data during CSE FW downgrade
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soc/intel/cse_lite: Back up PSR data during CSE FW downgrade

During CSE FW downgrade we erase CSE data. This would result in
Platform Service Record(PSR) data to be erased.

To avoid losing PSR data we need to take a backup before data clear.

This patch sends PSR_HECI_FW_DOWNGRADE_BACKUP HECI command to CSE,
informing the CSE to backup PSR data before a data clear operation
during downgrade.

To track the command send status we use CMOS address location 161.

BUG=b:273207144
TEST=build CB image for google/rex board and check PSR backup command
is being sent during a CSE FW downgrade. Also check PSR data is not
lost/erased after a downgrade using intel PSR tool.

Change-Id: I135d197b5df0a20def823fe615860b5ead4391f8
Signed-off-by: Anil Kumar 
---
M src/soc/intel/common/block/cse/cse_lite.c
M src/soc/intel/common/block/include/intelblocks/cse.h
2 files changed, 97 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/77/74577/43