For Librem 11 (Intel N5100, Jasper Lake), I had to revert 21e61847 [1] in order for FspMemoryInit to succeed for second and later boots.

If the MTRR is set in early_ramtop_enable_cache_range(), all JSL FSPs I tested fail FspMemoryInit with EFI_UNSUPPORTED.  Since there is no public FSP release for JSL, I tested the FSP binaries from a number of Chromebooks - buggzy, cret, boten, storo.

Before submitting a revert patch I wanted to discuss whether this should be conditionally enabled or reverted.  @Sean, I saw you authored this change, does it work for you?  Are there other FSP binaries available where this might work?

CC Matt DeVillier, as this will probably affect 4.21 releases of the MrChromebox UEFI firmware for JSL devices.

Thanks,
Jonathon

[1] https://review.coreboot.org/c/coreboot/+/74518