When you turn on a computer, it transfers code to software required to get the machine up and running reliably--the boot process. That used start in a chip called the BIOS. It's a 40-year old holdover from the early days of the IBM PC. UEFI is a more complex and feature-rich protocol. Due to its default memory management Go hasn't been considered the first choice for such purposes but this proof of concept uses Go for the very low level code needed for UEFI.