Mac Pro (late 2013 model) EFI and iPXE booting

[Pretzel]

There are a pile of Mac Pros (2013 model) in my office and I would love to figure out a way to get them to PXE boot. My office uses Clonezilla to clone the workstations across a computer lab. Clonezilla Server can boot a Clonezilla client via PXE. Our old Mac Book Pros from 2008 and 2012 all have legacy BIOS boot support and can successfully boot iPXE which then boots the Clonezilla client.

Unfortunately, the new Mac Pros (2013 mode) no longer have legacy BIOS support. I called Apple tech support and checked. (as an side, Apple proposed I use Netboot to connect to a bootp server to boot iPXE to then connect to the clonezilla server to PXE boot the clonezilla client. That sounds convoluted and error prone to me.)

Ergo, EFI booting is currently the only option.

So far, I've tried downloading the iPXE source code via git and compiling the code on my Ubuntu 14.04 machine via the "make bin-x86_64-efi/ipxe.efi" command. I took the "ipxe.efi" file in the "bin-x86_64-efi" directory and renamed it "bootx64.efi" and stuck in "/EFI/BOOT" folder on a USB flash drive. When the Mac Pro boots (using the Option key), it sees this file and gives me the option to EFI Boot. But when I select it, I briefly get a black screen and then it just boots into Mac OS.

I've done a good deal of reading in this forum and it appears that this "ipxe.efi" file may not work and that I need to patch the "efi_image.c" file manually and then compile the "snponly.efi" and use that as my "bootx64.efi". Is this still true? (The posts I was reading were a few months old.)

Also, is there another way to PXE boot on an EFI only computer that may be easier?

UPDATE 2014-06-25: See the last post in this thread for the solution