Mac Pro (late 2013 model) EFI and iPXE booting

[kiwi66]

I managed to get a small NetBoot "nbi" bundle working which can be served from MacOS X Server to have it boot into iPXE. And I see my Xserve further attempting to load pxelinux.0 afterwards. If anyone wants the nbi bundle, I can give it to you. It works with the default efi64bit build of the iPXE (make bin-x86_64-efi/ipxe.efi)

On my test setup, a MacBook Pro (Retina) with a Thunderbolt Ethernet adapter, I can also boot but then keyboard input its not accepted. CTRL-B doesn't have any effect and it attempts to continue to boot, fails and then goes into OS X.

If anyone has a hint on how to get the keyboard working and to skip pxelinux.0 and load linux kernels directly I would be thankful. My goal at the end is to network boot our pile of Xserves to then bootstrap into Linux installers so we can run them diskless due to built in RAID controllers which are not supported by anything else than OS X (and even there they always give battery faults and other defects).