Unified Extensible Firmware Interface (UEFI) is a specification for a software program that connects a computer’s firmware to its operating system (OS). UEFI is expected to eventually replace BIOS.
This BIOS have two types one is legacy BIOS and another one is UEFI. UEFI is a over come of legacy BIOS.
Like BIOS, UEFI is installed at the time of manufacturing and is the first program that runs when a computer is turned on. It checks to see what hardware components the computing device has, wakes the components up and hands them over to the operating system. The new specification addresses several limitations of BIOS, including restrictions on hard diskpartition size and the amount of time BIOS takes to perform its tasks.
Because, UEFI is programmable, original equipment manufacturer (OEM) developers can add applications and drivers, allowing UEFI to function as a lightweight operating system.
The Unified Extensible Firmware Interface is managed by a group of chipset, hardware, system, firmware, and operating system vendors called the UEFI Forum.The specification is most often pronounced by naming the letters U-E-F-I.
Features of UEFI
- 32 or 64 bit processor
- All system memory.
- Support graphical mode.
- Biometric authentication
- Faster startup
Installing operating system to UEFI – based computers
- Your UEFI firmware contains something very like what you think of as a boot menu.
- You can query its configuration with
efibootmgr -v, from any UEFI-native boot of a Linux OS, and also change its configuration with
efibootmgr(see the man page for details).
- This ‘boot menu’ can contain entries that say ‘boot this disk in BIOS compatibility mode’, ‘boot this disk in UEFI native mode via the fallback path’ (which will use the ‘look for BOOT(something).EFI’ method described above), or ‘boot the specific EFI format executable at this specific location (almost always on an EFI system partition)’.
- The nice, clean design that the UEFI spec is trying to imply is that all operating systems should install a bootloader of their own to an EFI system partition, add entries to this ‘boot menu’ that point to themselves, and butt out from trying to take control of booting anything else.
- Your firmware UI has free rein to represent this mechanism to you in whatever way it wants, and it may do this well, or it may do this poorly.
Let’s have a quick look at some specific consequences of the above that relate to installing operating systems on UEFI computers.