[coreboot-gerrit] Change in coreboot[master]: soc/intel/cannonlake: Enable FSP to use coreboot stack for cometlake

[Patrick Rudolph (Code Review)]

Patrick Rudolph has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/34130 )

Change subject: soc/intel/cannonlake: Enable FSP to use coreboot stack for cometlake
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Patch Set 5:
> Patch Set 5:
> > Patch Set 5:
> > > Patch Set 5: Code-Review-1
> > >
> > > It seems to affect FSP-M only, but that's not documented.
> > > It requires a huge amount of stack, why?
> > > The Documentation wasn't updated to explain this new feature. It seems independent of EFI_MP_SERVICES_PPI.
> >
> > Yes, it is required for FSP-M to execute, we'll have to allocate the stack out of CAR.
> > The stack requirement is due to FSP_M execution, configuring it for lesser value, we see hang during FSP-M execution. The value configured here is actually less the than the stack size that was reserved by FSP for the implementation when FSP was setting up different stack(0x28000).
> >
> > yes this is independent of the EFI_MP_SERVICES_PPI.
>
> Adding Nate if we have FSP2.1 spec available for Patrick.

The exact stack requirement should also be documented in the FSP_Integration_Guide.pdf that ships with each FSP release.