UEFI(8)                 FreeBSD System Manager's Manual                UEFI(8)

NAME
     UEFI - Unified Extensible Firmware Interface bootstrapping procedures

DESCRIPTION
     The UEFI Unified Extensible Firmware Interface provides boot- and run-
     time services to operating systems.  UEFI is a replacement for the legacy
     BIOS on the i386 and amd64 CPU architectures, and is also used on arm,
     arm64 and ia64.

     The UEFI specification is the successor to the Extensible Firmware
     Interface (EFI) specification.  The terms are often used interchangeably.

     The UEFI boot process loads system bootstrap code located in an EFI
     System Partition (ESP).  The ESP is a GPT or MBR partition with a
     specific identifier that contains an msdosfs(5) FAT file system with a
     specified file hierarchy.

           Partition Scheme        ESP Identifier
           GPT                     C12A7328-F81F-11D2-BA4B-00A0C93EC93B
           MBR                     0xEF

     The UEFI boot process proceeds as follows:
           1.   UEFI firmware runs at power up and searches for an OS loader
                in the EFI system partition.  The path to the loader may be
                set by an EFI environment variable.  If not set, an
                architecture-specific default is used.

                      Architecture    Default Path
                      amd64           /EFI/BOOT/BOOTX64.EFI
                      arm             /EFI/BOOT/BOOTARM.EFI
                      arm64           /EFI/BOOT/BOOTAA64.EFI

                The default UEFI boot configuration for FreeBSD installs
                loader.efi in the default path.
           2.   loader.efi reads boot configuration from /boot.config or
                /boot/config.
           3.   loader.efi loads and boots the kernel, as described in
                loader(8).

     The vt(4) system console is automatically selected when booting via UEFI.

FILES
     UEFI bootstrap
     /boot/loader.efi
                   Final stage bootstrap
     /boot/kernel/kernel
                   default kernel
     /boot/kernel.old/kernel
                   typical non-default kernel (optional)

SEE ALSO
     vt(4), boot.config(5), msdosfs(5), boot(8), efibootmgr(8), efidp(8),
     efivar(8), gpart(8), uefisign(8)

HISTORY
     EFI boot support for the ia64 architecture first appeared in FreeBSD 5.0.
     UEFI boot support for amd64 first appeared in FreeBSD 10.1; for arm64 in
     FreeBSD 11.0; for armv6 and armv7 in FreeBSD 12.0; and for riscv in
     FreeBSD 13.0.

FreeBSD 13.1-RELEASE-p6        February 22, 2021       FreeBSD 13.1-RELEASE-p6