Yeah it's possible to know the format by reading the Intel datasheets (sandybridge/ivybridge ones). Certain parts are "reserved" but have been reverse engineere

Yeah it's possible to know the format by reading the Intel datasheets (sandybridge/ivybridge ones). Certain parts are "reserved" but have been reverse engineered like you see in ifdtool. In Libreboot there is a tool that I wrote called ich9gen, which can entirely generate ich9 ifd+gbe from scratch. This does not exist yet for sandy/ivy i think, but yes there is that --dump option in ifdtool. By the way: bincfg is a nice tool in coreboot, and you can write a spec file for that, based on intel datasheet, to generate gbe/ifd images. I actually have this on my todo list, as I've been studying it. The datasheets are very confusing especially for the Gbe NVM region, making it look like it's not even documented, but it is, poorly.