This process is tedious but rewarding. You end up with a bit-perfect copy of your specific console’s BIOS, which may even have subtle manufacturing differences.
The Sega Saturn's BIOS serves a similar purpose. It's the firmware that initializes the console's hardware and provides a basic interface for the operating system (in this case, the Saturn's proprietary OS) to interact with the hardware. The BIOS also includes a region lock, which historically prevented the console from playing games from different regions without modification. Sega Saturn Bios Mpr-17933.bin