Attention is currently required from: Subrata Banik, Wonkyu Kim, Paul Menzel. Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/63615 )
Change subject: intel/common/../systemagent: Enable MCHBAR in bootblock ......................................................................
Patch Set 4:
(1 comment)
Commit Message:
https://review.coreboot.org/c/coreboot/+/63615/comment/81f14cb4_99cdbf89 PS4, Line 10: As there is no harm to enable : MCHBAR from bootblock even in existing plaforms
Enabling MCHBAR takes a PCI config register write or two, so size isn't a concern. The main reason is that the GPMR driver needs to access MCHBAR registers in bootblock code.
+1 to Angel's question. do we need to use GPMR access even in bootblock. Today with ADL and previous generation I don't see such usage.
Well, only MTL needs MCHBAR access to configure GPMR stuff, the registers are in DMI PCR space for older platforms. AFAIUI, the GPMR driver is needed to configure some decode ranges in bootblock, I think stuff like ACPIBASE, PMBASE, SMBUS TCOBASE, LPC I/O enable/decode, etc. could need the GPMR driver in bootblock.