BIOS
From Just Solve the File Format Problem
BIOS (Basic Input Output System), is a ROM chip containing code (firmware) to control peripherals attached to a wikipedia:PC.
The x86 BIOS entry point is located at physical address 0xfffffff0 (usually corresponding to 16 bytes from the end of the BIOS image) and is executed in 16-bit real mode; it usually contains a jump instruction (either far or near). There are no other guarantees about BIOS image layout, although many vendors have developed in-house formats.
UEFI firmware images usually contain an embedded Firmware File System.
