UEFI, short for Unified Extensible Firmware Interface, is a firmware standard for boot ROM designed to replace legacy BIOS and provide a stable API for interacting with system hardware. Like Open Firmware it is designed to be an architecture independent platform independent of CPU instruction set. Any boot ROM that conforms to the UEFI specification is a UEFI ROM. There are multiple implementations, including the open source TianoCore EDK II which serves as the UEFI reference implementation.
The open source hardware initializer ROM Coreboot can deploy UEFI, BIOS, and Open Firmware boot ROMs among others.
- BIOS — the firmware of choice for each IBM-compatible PC until a few years ago.
- Coreboot — a free and opensource hardware initializing firmware which supports multiple boot ROM payloads.
- Open Firmware — a standard Forth-based firmware popularized by PowerPC Macs which sees continued use with the OpenBIOS project.