I've  been poking around a bit more on system I'm attempting to port and started doing a detailed comparison between the FSP settings from the stock BIOS and what Coreboot is using.  In going through the FSP settings,  I'm noticing there are a few pointers to external tables that aren't very well documented.

For example, the CoffeeLake FSP  has "ChipsetInitBinPtr" / "ChipsetInitBinLen"   fields, but their documentation doesn't seem to say anything beyond the names.  Couldn't find any other code referencing these.