Patrick Rudolph has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40520 )
Change subject: [RFC]drivers/smmstore: Implement SMMSTORE version 2 ......................................................................
Patch Set 1:
(2 comments)
https://review.coreboot.org/c/coreboot/+/40520/1/src/drivers/smmstore/store.... File src/drivers/smmstore/store.c:
https://review.coreboot.org/c/coreboot/+/40520/1/src/drivers/smmstore/store.... PS1, Line 270: static struct smmstore_params_info info_params;
So smmstore_update_info has to be called before any of the other operations can be used? Would you w […]
Good point, I'll rework that
https://review.coreboot.org/c/coreboot/+/40520/1/src/include/smmstore.h File src/include/smmstore.h:
https://review.coreboot.org/c/coreboot/+/40520/1/src/include/smmstore.h@40 PS1, Line 40: * Version 2 of the SMM requires as SMMSTORE of at least 256KiB of size, that : * has to be aligned to 64KiB. : * This allows the payload to store raw data in the SMMSTORE flash region. : * This can be used by a FaultTolerantWrite implementation, that uses at least : * two regions in an A/B update scheme.
Why is 256KiB needed if you have A/B (2) regions of 64KiB? Or is it typical to need 2 x 64KiB region […]
64KiB is the minimum for UEFI variable store + 64KiB as FaultTolerantWrite backup. But there's also the FtwSpare Block, for which I'm not sure what it is used for. Yes it uses 64KiB as that block size should be supported by all the flash chips.