I recently posted a patch that would allow the coreboot build to use a saved SeaBIOS .config file stored in the mainboard directory. The initial reason for this was to replace one existing SeaBIOS configuration option that was in coreboot's Kconfig, and to remove the need for a second option that was about to be added.
The intention behind this is not to add full config files, but to add individual options that are required for the platforms. That said, saving a full config will almost certainly happen at some point since this change doesn't prevent this. I'm not sure how big an issue this really is, other than creating some maintenance problems.
Another side effect of this is that a user could point to a saved .config outside of the coreboot tree, to customize the SeaBIOS. I don't think this should present a problem, as the .config file for SeaBIOS is getting saved in CBFS. If we want to minimize this, the prompt in Kconfig can be removed, preventing the option from showing up in menuconfig (or your favorite config method).
It was requested that I post this change to the mailing list for thoughts and review.
The patches in question are here:
payloads/external/SeaBIOS: Add option for saved SeaBIOS .config https://review.coreboot.org/#/c/12568
intel/mohonpeak: Change SEABIOS_MALLOC_UPPERMEMORY to config_seabios https://review.coreboot.org/#/c/12569
SeaBIOS/Kconfig: Remove SEABIOS_MALLOC_UPPERMEMORY option https://review.coreboot.org/#/c/12570
payloads/Seabios: add SEABIOS_NO_HARDWARE_IRQ symbol https://review.coreboot.org/#/c/12534/
Thoughts? Review? Downsides I didn't think of?