Unified Extensible Firmware Interface

The Unified Extensible Firmware Interface (UEFI) is a blueprint that defines acomputer application interface amid an operating arrangement and belvedere firmware. UEFI is a added defended backup for the earlier BIOS firmware interface, present in all IBM PC-compatible claimed computers, which is accessible to bootkit malware.12

The aboriginal EFI (Extensible Firmware Interface) blueprint was developed by Intel. In 2005, development of the EFI blueprint accomplished in favour of UEFI, which had acquired from EFI 1.10. The UEFI blueprint is actuality developed by the industry-wide alignment Unified EFI Forum.

UEFI is not belted to any specific processor architectonics and can run on top of, or instead of, earlier BIOS implementations

Disk device compatibility

In accession to the accepted PC deejay allotment scheme, which uses a adept cossack almanac (MBR), EFI works with a fresh administration scheme: GUID Allotment Table (GPT). GPT is chargeless from abounding of the limitations of DOS MBR. In particular, the DOS MBR banned on the cardinal and admeasurement of deejay partitions (up to 4 partitions per disk, up to 2.2 TB (241 bytes) per disk) are relaxed.12 GPT allows for a best deejay and allotment admeasurement of 9.4 ZB (273 bytes).1213 The EFI blueprint does not appoint any accurate book system. The alone Microsoft Windows versions that can cossack from disks beyond than 2.2 TB are 64-bit versions of Windows Vista and after applicant operating systems, Windows Server 2008 and later, and the Itanium versions of Windows Server 2003 and Windows XP.

Device drivers

In accession to accepted architecture-specific accessory drivers, the EFI blueprint provides for a processor-independent accessory disciplinarian environment, alleged EFI Byte Code or EBC. Arrangement firmware is appropriate by the UEFI blueprint to backpack an analyst for any EBC images that abide in or are loaded into the environment. In that sense, EBC is agnate to Open Firmware, the hardware-independent firmware acclimated in PowerPC-based Apple Macintosh and Sun Microsystems SPARC computers, amid others.

Some architecture-specific (non-EBC) EFI accessory disciplinarian types can accept interfaces for use from the operating system. This allows the OS to await on EFI for basal cartoon and arrangement functions until OS specific drivers are loaded

Booting

UEFI does not await on a alive cossack area only, but needs a appropriate allotment table apropos to a appropriate allotment absolute a distinctively amid book with a connected name depending on the absolute architectonics to cossack (\EFI\BOOT\bootarchitecture name.efi).

Boot loaders are a chic of UEFI applications. As such, they are stored as files on a book arrangement that can be accessed by the firmware. Cossack variables, stored in NVRAM, announce the paths to the loaders. Cossack loaders can additionally be auto-detected by firmware, for instance to accredit booting on disposable devices.

It is accepted for UEFI firmware to accommodate a cossack manager, to acquiesce the user to baddest and amount the operating arrangement amid the accessible options