These option ROMs are known to cause a system hang. If you insert an empty
option ROM into CBFS, it disables any option ROM loading for those devices
when using SeaBIOS.
2MiB and 16MiB were the only flash sizes supported. 4 and 8MiB have been
added.
Now there are only libgfxinit_txtmode configs.
Use seabios_withgrub or seabios_grubfirst ROMs if you wish to use an add-on
GPU.