Was randomly trawling the Framework forums this morning and stumbled across this thread about enabling Resizable BAR. It was originally opened about a year ago. Whilst the participants in there have found some workarounds to enable ReBAR, there’s never been any official Framework assistance or response to this matter.
I think this is a great example of why we need something like coreboot. ReBAR didn’t matter so much a couple of years ago (though I do remember messing with it years ago whilst trying to get GPU passthrough working under Xen…), but it matters more today with the mainstream release of Arc GPUs.
Looks like coreboot supports ReBAR enablement: https://github.com/coreboot/coreboot/blob/master/src/device/Kconfig#L668
So, pretending that we already had coreboot firmware shipped when this thread was first opened, I can imagine a scenario where someone from the community says “huh, let me try a build of coreboot with PCIEXP_SUPPORT_RESIZABLE_BARS enabled…”, produces said build, and it’s available for testing the next day, and in a stable release the next week/month.