Go into your git checkout folder of ipxe.
Save the below file as nic-menu.ipxe
.
Build iPXE like this:
cd src && make EMBED=../nic-menu.ipxe && cd ..
Requirements: current iPXE as of 2013-08-01 (for proper behavior of autoboot with a network device specified, netX feature, PCI vendor/device ID display and inc command)