Locating GRUB2

On a BIOS machine, GRUB2 does not exist as a monolithic file. It takes more than one shape and form, depending on the boot stage. The first form of GRUB2 is a binary code on a section on the MBR of a bootable disk. Once the linux firmware locates that form of GRUB2, it loads it in memory. The program then relies on the GRUB2-related files under /boot/ and /etc/ to respectively load the main image of GRUB2 and read the configuration.