[M] Change in coreboot[master]: mb/purism/librem_cnl: Provide CBFS setting for Mini auto power on

[Jonathon Hall (Code Review)]

Attention is currently required from: Paul Menzel, Angel Pons, Felix Held.

Jonathon Hall has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74363 )

Change subject: mb/purism/librem_cnl: Provide CBFS setting for Mini auto power on
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Patch Set 3:

(1 comment)

Patchset:

PS2:
> I only found the general `Documentation/lib/option.md`. Otherwise, `cmos.layout` and `cmos. […]

Looks like if I enable HAVE_OPTION_TABLE, USE_OPTION_TABLE, and STATIC_OPTION_TABLE it is quite close to what I want - then I could inject a cmos.default into CBFS and it is always applied on boot, otherwise it doesn't touch CMOS.  Which would be great to avoid inventing some board-specific thing!

However, it currently always writes to BRAM bank 0 starting from offset 14.  The Mini's EC firmware has this setting in bank 1 at offset 41 and I don't currently know what the other offsets do, if anything.

Do you think it'd be reasonable to add Kconfigs to specify the BRAM bank BAR (so you could point it to bank 1, or nondefault address for bank 0 if some device required it) and the start offset?