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UEFI(8)                DragonFly 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 arm64
     and ia64.

     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 msdos(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, the default
                is /EFI/BOOT/BOOTX64.EFI.  The default UEFI boot configuration
                for DragonFly installs boot1.efi as /EFI/BOOT/BOOTX64.EFI.
           2.   boot1.efi reads boot configuration from /boot.config or
                /boot/config.  Unlike other first-stage boot loaders,
                boot1.efi passes the configuration to the next stage boot
                loader and does not itself act on the contents of the file.
           3.   boot1.efi searches partitions of type `DragonFly UFS1' and the
                first disklabel64(5) partition in GPT partitions of type
                `DragonFly Label64' for loader.efi.  The search begins with
                partitions on the device from which boot1.efi was loaded, and
                continues with other available partitions.  boot1.efi then
                loads and executes loader.efi.
           4.   loader.efi loads and boots the kernel, as described in
                loader(8).


FILES

     /boot/boot1.efi
                   First stage UEFI bootstrap
     /boot/loader.efi
                   Final stage bootstrap
     /boot/kernel/kernel
                   default kernel
     /boot/kernel.old/kernel
                   typical non-default kernel (optional)


SEE ALSO

     efivar(3), disklabel64(5), msdos(5), boot(8), efibootmgr(8), efidp(8),
     efisetup(8), efivar(8), uefisign(8)


HISTORY

     UEFI boot support first appeared in FreeBSD 10.1 and was brought into
     DragonFly 4.5.


AUTHORS

     UEFI boot support was developed by Benno Rice <benno@FreeBSD.org>, Ed
     Maste <emaste@FreeBSD.org>, and Nathan Whitehorn
     <nwhitehorn@FreeBSD.org>.  The FreeBSD Foundation sponsored portions of
     the work.


CAVEATS

     EFI environment variables are not supported by loader(8) or the kernel.

DragonFly 5.9-DEVELOPMENT        June 13, 2020       DragonFly 5.9-DEVELOPMENT

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