[gPXE] hang after "gPXE (PCI 08:00.0) Starting execution".

[Stefan Hajnoczi]

We can get an idea of how gPXE has been loaded and hooked into the
boot process if you send the first line printed by the gPXE option
ROM.

It should look something like this:
gPXE (http://etherboot.org) - 00:00:0 D100 PCI2.10 PnP BBS PMM07E0 at 10 D100

The "Starting execution" output you have described means that the BIOS
has passed control to gPXE.  Now gPXE will decompress itself and begin
execution.

If you are able to test out a few ROMs we can hopefully discover where
things are going wrong.  Do you want to try debugging this issue?

Stefan