UEFI - Revision history

Anonymoususer852: Remove .rcv from list of extensions, describe exceptions to the listed extensions, these are vendor/hardware specific.

2025-08-15T09:20:23Z

Remove .rcv from list of extensions, describe exceptions to the listed extensions, these are vendor/hardware specific.

Anonymoususer852: Add note about ESP, and its importance.

2025-08-13T22:56:47Z

Add note about ESP, and its importance.

Anonymoususer852: Created page with "{{FormatInfo |formattype=electronic |subcat=Firmware |extensions={{noext}}, {{ext|bin}}, {{ext|efi}}, {{ext|rcv}} }} '''UEFI''' (Unified Extensible Firmware Interface) is a co..."

2025-08-13T22:38:15Z

Created page with "{{FormatInfo |formattype=electronic |subcat=Firmware |extensions={{noext}}, {{ext|bin}}, {{ext|efi}}, {{ext|rcv}} }} '''UEFI''' (Unified Extensible Firmware Interface) is a co..."

New page

{{FormatInfo
|formattype=electronic
|subcat=Firmware
|extensions={{noext}}, {{ext|bin}}, {{ext|efi}}, {{ext|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), <code>/sys/firmware/efi/efivars</code> 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 ==
* [https://github.com/rhboot/efibootmgr efibootmgr] (Linux only) - Allows viewing and manipulation of entries in <code>/boot/efi</code> or <code>/boot/esp</code>
* [https://github.com/LongSoft/UEFITool/releases UEFITool] - Viewer and editor of firmware images conforming to UEFI Platform Interface (PI) Specifications.

== Links ==
* [[wikipedia:UEFI]]
* [https://superuser.com/questions/1576938/how-to-extract-system-specific-data-from-uefi-bios-mac-address-sn-uuid-msdm How to extract system specific data from UEFI BIOS? (MAC address, SN, UUID, MSDM key, etc.) - Stack Exchange]
* [https://www.tianocore.org/ tianocore - community supporting an open source implementation of the Unified Extensible Firmware Interface (UEFI)]

@@ Line 2: / Line 2: @@
 |formattype=electronic
 |subcat=Firmware
-|extensions={{noext}}, {{ext|bin}}, {{ext|efi}}, {{ext|rcv}}
+|extensions={{noext}}, {{ext|bin}}, {{ext|efi}}
 }}
 {{notice|1=Please do not delete/format your EFI System Partition, you may not be able to boot back into your OS if you do so.}}
-'''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.
+'''UEFI''' (Unified Extensible Firmware Interface) is a specification and 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):
@@ Line 18: / Line 18: @@
 UEFI compliant OS takes advantage of sharing ESP, thereby eliminating the need to worry about bootloaders being overwritten by another OS, especially if dual-booting or multi-booting. For example, [[Microsoft Windows]] is known to typically overwrite MBR with its own bootloader, and this would prevent [[Linux]] from being booted. Backing MBR (on [[BIOS]] only machines) were tricky, but even with UEFI, it is still recommended to backup your ESP to prevent rendering the loss of your OS choice.
 == Software ==
@@ Line 27: / Line 29: @@
 * [https://superuser.com/questions/1576938/how-to-extract-system-specific-data-from-uefi-bios-mac-address-sn-uuid-msdm How to extract system specific data from UEFI BIOS? (MAC address, SN, UUID, MSDM key, etc.) - Stack Exchange]
 * [https://www.tianocore.org/ tianocore - community supporting an open source implementation of the Unified Extensible Firmware Interface (UEFI)]