Clear settings on CMOS reset

[mkopec]

The problem you're addressing (if any)

With some features like BIOS password, option rom verification or fast boot, it's possible to misconfigure the BIOS in such a way that entering the setup menu again may be difficult or impossible.

Describe the solution you'd like

Have a way to reset BIOS settings. CMOS reset is the usual way to do this, even though settings are not actually stored in CMOS at all. coreboot could detect a CMOS reset and wipe the entire SMMSTORE region, resetting all settings to default.

Where is the value to a user, and who might that user be?

Easier recovery in case something goes wrong

Describe alternatives you've considered

No response

Additional context

Some UEFI implementations don't clear all settings, for example ThinkPads store BIOS password in the EC and it can't be reset easily. This makes a stolen laptop with a BIOS password worthless to a common thief, requiring expensive tools and expertise to restore functionality. That might be a valuable feature to consider

[miczyg1]

Feel free to pick the commits from : https://github.com/Dasharo/coreboot/commits/msi_mem_oc/

Dasharo/coreboot@2b23493
Dasharo/coreboot@0eec2e4

Although one may put the call somewhere else than mainboard's bootblock entry