Bart has BBIE which creates an image of a boot sector of a CD. All 2048 bytes of it. Bart's MKBT can apparently put a boot sector onto a USB flash stick but only a floppy boot sector like 512KB or ...
Essentially, all I need to do is figure out how to make Clonezilla run from sda3, execute a command, and then reboot. Or, alternatively, make a very basic Linux installation which boots, executes a ...