Is it possible to generate UEFI disk images from within a BIOS machine? If so, how do you make this bootloader installation with Kickstart? AFAIU bootloader kickstart command installs the bootloader for BIOS as it is running in a BIOS machine.
EDIT:
We are trying to build a disk image with Koji. To do so, it spawns a QEMU VM, which by default is using BIOS. Then it runs a kickstart file for configuring it. We want this configuration to allow this image to run on both BIOS and UEFI machines. Avoid having one image for each. We have seen that this is possible with https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-disk1.img as it boots fine in both.