[coreboot-gerrit] [L] Change in coreboot[master]: drivers/smm_payload_interface: Add initial support for SMM payload

[Benjamin Doron (Code Review)]

Attention is currently required from: Nico Huber, Michał Żygowski, Martin L Roth, Patrick Rudolph, Paul Menzel, Arthur Heymans.

Benjamin Doron has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/70378 )

Change subject: drivers/smm_payload_interface: Add initial support for SMM payload
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Patch Set 11:

(2 comments)

Patchset:

PS11:
> Out of curiosity, what happened to the idea to only read and verify updates […]

We considered moving the variable stack into coreboot, but it would be a lot of work: multiple modules, many libraries, all of it assuming the presence of a UEFI environment.

Or are you referring to CB:64072?

File Documentation/drivers/s3_save_restore.md:

https://review.coreboot.org/c/coreboot/+/70378/comment/26dfb52d_8a5752c1 
PS8, Line 8: with differing register definitions
> How does your implementation (this patchset) support many silicon generations with differing registe […]

Since soc/intel/ has common header path layout and `#define`s, cbtable.c just includes its necessary headers. At compile-time, the build-system's `-I` options retrieve the SoC-specific header.

https://github.com/benjamindoron/edk2/commit/a5960607ddfdd0430c3ba2 parses these to the required HOBs, which will be used by https://github.com/tianocore/edk2/blob/1eeca0750af5af2f0e78437bf791ac2de74bd..., https://github.com/tianocore/edk2/blob/1eeca0750af5af2f0e78437bf791ac2de74bd... and https://github.com/tianocore/edk2/blob/1eeca0750af5af2f0e78437bf791ac2de74bd....

I can elaborate on this in this document's "design flow" section too.