@baptistepds Well then we do find that sometimes there is no hope because of a hardware conflict between ipxe and the firmware. We do have one last method to boot bzImage directly fro a usb flash drive. You will lose multicasting and “Deploy image” functions because iPXE isn’t there, but you will still be able to unicast an image onto this computer.
Read through the tutorial completely so you understand the caveats and also look at the forum chat for some additional hints: https://forums.fogproject.org/topic/7727/building-usb-booting-fos-image