For ubuntu/kubuntu by @kmstory https://forums.fogproject.org/topic/10403/boot-iso-from-ipxe-menu/5 Note that you will need to place the ubuntu extracted images in /images/ubuntu on the fog server to access them via nfs. If you are using fog 1.3.0+ you can use the built in functions to build the ipxe boot menu.

kernel nfs://${next-server}/images/xubuntu/casper/vmlinuz.efi initrd nfs://${next-server}/images/xubuntu/casper/initrd.lz imgargs vmlinuz.efi acpi=off root=/dev/nfs boot=casper netboot=nfs nfsroot=${next-server}:/images/xubuntu locale=en_US.UTF-8 keyboard-configuration/layoutcode=us mirror/country=US boot