UEFI

File Format
Name	UEFI
Ontology	Electronic File Formats Firmware UEFI
Extension(s)	(none), .bin, .efi, .rcv

UEFI (Unified Extensible Firmware Interface) is a code that replaces BIOS in the boot ROM. Many modern devices, particularly those with 64bit x86 CPU or ARM SoC (System on a Chip), have UEFI.

Typically, machines with UEFI and are booted with UEFI enabled, would have a partition on the storage medium known as ESP (EFI System Partition). This partition is formatted as FAT32 as per UEFI specifications, and all UEFI compliant operating systems would have their EFI files stored in the same partition. Other tell-tale signs involve (but are not limited to):

• System configuration screen or system manual describing the likes of CSM (Compatibility Support Module), Secure Boot, a mouse driven interface^*,
• Use of GPT (GUID Partition Table) as opposed to MBR (Master Boot Record)^*2,
• (In Linux mainly), /sys/firmware/efi/efivars is present and accessible for instance.

^*: Exceptions to this rule may apply to older machines, usually with AMIBIOS (American Megatrends Inc BIOS), which may have a mouse driven interface.

^*2: This is likely not part of UEFI specification, it is possible to have UEFI on MBR.

Software

• efibootmgr (Linux only) - Allows viewing and manipulation of entries in /boot/efi or /boot/esp
• UEFITool - Viewer and editor of firmware images conforming to UEFI Platform Interface (PI) Specifications.

Links

• wikipedia:UEFI
• How to extract system specific data from UEFI BIOS? (MAC address, SN, UUID, MSDM key, etc.) - Stack Exchange
• tianocore - community supporting an open source implementation of the Unified Extensible Firmware Interface (UEFI)