The first part (stage 1) is stored in the first 448 bytes, which is responsible for passing control to the so-called stage 1.5, located a little later in memory. This stage finally loads stage 2 from the /boot folder, and transfers control to it.
The names "stage1", "stage1.5" and "stage2" belong to GRUB Legacy, i.e. GRUB versions 0.xx. When stage 1 is ...
If you look at the sources of GRUB, available here, you find stage1 is actually defined at grub/grub-core/boot/i386/pc/boot.S.
It can perform a floppy boot if configured. It does boot from a configured harddisk, and it needs to know which C/H/S it has to load stage1.5 from. The only automatic function it has is determining which drive the boot sector was ...
The dumpet output indicates the original contains two ElTorito boot images: one for BIOS-style boot and another for UEFI. After specifying the first boot image for BIOS with mkisofs options, you would need to use the -eltorito-alt-boot and -eltorito-platform efi options to specify a second boot image. Something like this:
sudo mkisofs \
You can install Fedora version 27 or later. Fedora included the required files on it's standard 64bit ISO installer. However Fedora doesn't have the LTS option that Ubuntu has.
Ubuntu as of 18.04 LTS does not support this out of the box. People have jumped through hoops to get these installs done, but it isn't trivial.