After much research into this.. I tried building the config: som-db5800-som-6867_defconfig
which uses the baytrail E3845 from the master branch, commit ID: 8d24789abed0822fbe41a2f9d72cf19650159dc6 with GCC version: 11.5.0 on Ubuntu: 24.04.4 When built from that environment u-boot gets past the stage that I was troubleshooting. This has been confirmed on both the Advantech SOM-DB5800 as well as our custom hardware. In light of this discovery, please disregard my previous two patch submissions: "Fix x86 baytrail boot flow." "Fix x86 baytrail boot flow, UPD/VPD Updates" Eric Schikschneit Senior Embedded Linux Engineer III
