Kyösti Mälkki has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/30499 )
Change subject: mb/qemu-{i440fx,q35}: Use POSTCAR stage to load the ramstage ......................................................................
Patch Set 3:
(2 comments)
https://review.coreboot.org/#/c/30499/3/src/mainboard/emulation/qemu-i440fx/... File src/mainboard/emulation/qemu-i440fx/romstage.c:
https://review.coreboot.org/#/c/30499/3/src/mainboard/emulation/qemu-i440fx/... PS3, Line 44: postcar_frame_add_mtrr(&pcf, 0, qemu_get_memory_size() * KiB, You need to honour MTRR alignment requirements here. Sort of.
From what I remember MTRRs are just dummy backup stores on QEMU, i.e. you can read back what you write there, so I think these poscar_frame_add_xx() calls don't make any sense.
https://review.coreboot.org/#/c/30499/3/src/mainboard/emulation/qemu-q35/rom... File src/mainboard/emulation/qemu-q35/romstage.c:
https://review.coreboot.org/#/c/30499/3/src/mainboard/emulation/qemu-q35/rom... PS3, Line 42: postcar_frame_add_romcache(&pcf, MTRR_TYPE_WRPROT); As before, MTRRs are dummies on QEMU, AFAIR.