Felix Held has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/58386 )
Change subject: cpu/x86/lapic: Unconditionally use CPUID leaf 0xb if available ......................................................................
Patch Set 7:
(1 comment)
Patchset:
PS7: uh oh, should have verified this patch on hardware. turns out that it breaks the picasso amd soc (tested on mandolin) and possibly also the other amd socs. with just the change in the header file, something goes so wrong that it'll get us back into bootblock:
Relocation complete. Invalid CPU number assigned in SMM stub: 8
coreboot-4.14-4020-gceaf959678-dirty Sat Feb 5 07:46:50 UTC 2022 bootblock starting (log level: 7)...
with the changes to the .S file applied it gets stuck with this being the last 3 lines of output:
CPU #1 initialized bsp_do_flight_plan done after 378 msecs. A
reverting this commit made the current coreboot master boot again on mandolin, but i'm not sure if the later patches in this area have some dependency on this one