FreeBSD manual
download PDF document: efi.8.pdf
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 riscv architectures.
The UEFI specification is the successor to the Extensible Firmware
Interface (EFI) specification. The terms UEFI and EFI 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 managed by efibootmgr(8).
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
i386 /EFI/BOOT/BOOTIA32.EFI
riscv /EFI/BOOT/BOOTRISCV64.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.efi(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), loader.efi(8), uefisign(8)
There is no support for 32-bit i386 booting via UEFI.
FreeBSD 14.0-RELEASE-p11 August 31, 2023 FreeBSD 14.0-RELEASE-p11