X1 Gen1 Carbons hang when trying to get a DHCP address through the embedded script

[nappington]

sorry - for some reason I pasted the wrong link for the image. Ifstat net0 produces the following:

http://imgur.com/GdtXuVU

I'm compiling the iPXE binary pretty much with default settings from source - at least, I haven't been building it with .efirom.

I'm fairly certain I'm using UNDI, since I'm compiling undionly.kpxe with an embedded script to break out of the loop. (But how do I check?)