Furquan Shaikh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/42453 )
Change subject: soc/intel/jasperlake: Add the SkipCpuReplacementCheck configuration ......................................................................
Patch Set 4:
(1 comment)
https://review.coreboot.org/c/coreboot/+/42453/4/src/soc/intel/jasperlake/ch... File src/soc/intel/jasperlake/chip.h:
https://review.coreboot.org/c/coreboot/+/42453/4/src/soc/intel/jasperlake/ch... PS4, Line 293: uint8_t SkipCpuReplacementCheck;
Thank you Angel Pons for sharing the bigger picture and educating me. […]
Setting this flag ensures that MRC re-training is not forced even if the CPU replacement flag is set. This is required for CSE Lite because with CSE Lite a device can downgrade to an older version of the firmware. In this case, coreboot clears all CSE data to avoid incompatibilities. This results in CPU replacement flag being set. However, we don't really want to force a memory retraining in this condition. Hence, the UPD is set in case of CSE Lite. This isn't yet set for CML or TGL because the CSE downgrade changes are not yet merged.