usb-and-pxe-installers/usbboot.img
Added /EFI/BOOT/ directory containing elilo.
Thanks to Erik_FL on LQ for pointing out that a boot image for UEFI did not
need to have a GPT partition table. Seems it works either way, but since
GPT is not required that allows us to add the support for UEFI boot to the
regular USB installer image. Unfortunately, this image still does not
work any better (or differently) as an El-Torito boot image for EFI on
an ISO. In tests here, elilo loads but runs into an error while loading
the initrd. I've experimented with different -boot-load-size options
(including way too large to be sure the whole image is mapped) but so
far it has not worked. If anyone figures out the trick to making this work,
let me know. It would be nice to have the DVD bootable under UEFI, and it
wouldn't take any extra space since the usbboot.img file will be on the
disc anyway.