Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/48500 )
Change subject: arch/x86: Simplify .id section ......................................................................
Patch Set 3:
Nico, the solution in FILO of checking COREBOOT_VERSION in .id section does not work with UPDATE_IMAGE=y, fallback/normal choice or VBOOT? It's not really a problem to maintain .id for x86, but seems to me the feature of FILO flashupdate needs an update anyways.
The upstream FILO code looks stale anyway. I've looked into it though, and our production version does the same annoying check. You are right, it only works for very plain images. Or rather, images with the .id in the right spot. With UPDATE_IMAGE we were used to keep the original bootblock around, so I don't see a problem there. A VBOOT "update" with RW only wouldn't work.
I can look into updating that FILO code when we settled for a CBFS solution. If maintaining compatibility on the coreboot side is making any trouble, I would also not block it. My original concern was mostly about other potential users that don't have a voice here. Having a transition period would be nice, but is not a strong requirement.