UEFI

Definitions

1. UEFI, or Unified Extensible Firmware Interface, is the modern firmware specification that has largely replaced the traditional BIOS as the interface between a computer's operating system and its hardware. UEFI provides several advantages over legacy BIOS: support for drives larger than 2.2 TB through the GPT (GUID Partition Table) partitioning scheme, faster boot times through parallel initialization, a graphical setup interface with mouse support, Secure Boot (which verifies that boot software is signed and trusted to prevent rootkits), networking capabilities before the OS loads, and a modular, extensible architecture. UEFI operates in 32-bit or 64-bit mode rather than the 16-bit real mode of BIOS, enabling access to all system memory during boot. It stores boot configuration in NVRAM variables rather than relying on a fixed MBR boot sector. Most modern PCs ship with UEFI firmware that includes a Compatibility Support Module (CSM) for legacy BIOS emulation when needed. UEFI is maintained by the UEFI Forum, an industry consortium.

   In plain English: The modern replacement for BIOS on PCs. It does the same basic job of starting up your computer, but it's faster, supports bigger hard drives, has a fancier interface, and can verify that the software it loads hasn't been tampered with.

   Example: "Secure Boot in UEFI rejected the unsigned kernel module, which is exactly what it should do — unless you're trying to load a custom driver at 2 AM."

Related Terms

• Kernel
• Bootloader
• BIOS
• Interrupt
• Von Neumann Bottleneck
• Compare-and-Swap
• Quantum Computing
• Physical Memory
• USB Protocol