UEFI - lersek/edk2 GitHub Wiki
The Unified Extensible Firmware Interface, or UEFI, specifies the firmware layer between an operating system and platform hardware. UEFI replaces the legacy Basic Input Output System (BIOS).
UEFI related specifications also cover various other aspects of firmware below the firmware/OS interface. These specifications can be found at http://www.uefi.org. Our community supports these UEFI specifications.