NAME efibootmgr - manipulate the EFI Boot Manager

SYNOPSIS efibootmgr [ -a ] [ -A ] [ -b XXXX ] [ -B XXXX ] [ -c ] [ -d DISK ] [ -e 1|3|-1 ] [ -E NUM ] [ -g ] [ -H XXXX ] [ -i NAME ] [ -l NAME ] [ -L LABEL ] [ -n XXXX ] [ -N ] [ -o XXXX,YYYY,ZZZZ ... ] [ -O ] [ -p PART ] [ -q ] [ -t seconds ] [ -T ] [ -u ] [ -U XXXX ] [ -v ] [ -V ] [ -w ] [ -@ file ]

DESCRIPTION efibootmgr is a userspace application used to modify the Intel Extensi- ble Firmware Interface (EFI) Boot Manager. This application can create and destroy boot entries, change the boot order, change the next run- ning boot option, and more.

Details on the EFI Boot Manager are available from the EFI Specifica- tion, v1.02 or later, available from: <URL:http://developer.intel.com>

Note: efibootmgr requires that the kernel support access to EFI non-volatile variables (through /proc/efi/vars on 2.4 kernels, /sys/firmware/efi/vars on 2.6 kernels). modprobe efivars should do the trick.

OPTIONS The following is a list of options accepted by efibootmgr:

-a | --active Sets bootnum active

-A | --inactive Sets bootnum inactive

-b | --bootnum XXXX Modify BootXXXX (hex)

-B | --delete-bootnum Delete bootnum (hex)

-c | --create Create new variable bootnum and add to bootorder

-d | --disk DISK The disk containing the loader (defaults to /dev/sda)

-e | --edd 1|3|-1 Force EDD 1.0 or 3.0 creation variables, or guess.

-E | --device NUM EDD 1.0 device number (defaults to 0x80)

-g | --gpt Force disk with invalid PMBR to be treated as GPT

-H | --acpi_hid XXXX set the ACPI HID (used with -i)

-i | --iface NAME create a netboot entry for the named interface

-l | --loader NAME Specify a loader (defaults to elilo.efi)

-L | --label LABEL Boot manager display label (defaults to "Linux")

-n | --bootnext XXXX Set BootNext to XXXX (hex)

-N | --delete-bootnext Delete BootNext

-o | --bootorder XXXX,YYYY,ZZZZ Explicitly set BootOrder (hex)

-O | --delete-bootorder Delete BootOrder

-p | --part PART Partition number containing the bootloader (defaults to 1)

-q | --quiet Quiet mode - supresses output.

--test filename Dont write to NVRAM, write to filename.

-t | --timeout seconds Boot Manager timeout, in seconds.

-T | --delete-timeout Delete Timeout variable.

-u | --unicode | --UCS-2 pass extra command line arguments as UCS-2 (default is ASCII)

-U | --acpi_uid XXXX set the ACPI UID (used with -i)

-v | --verbose Verbose mode - prints additional information

-V | --version Just print version string and exit.

-w | --write-signature write unique signature to the MBR if needed

-@ | --append-binary-args append extra variable args from file (use - to read from stdin). Data in file is appended as command line arguments to the boot loader command, with no modification to the data, so you can pass any binary or text data necessary.


DISPLAYING THE CURRENT SETTINGS (MUST BE ROOT). [root@localhost ~]# efibootmgr BootCurrent: 0004 BootNext: 0003 BootOrder: 0004,0000,0001,0002,0003 Timeout: 30 seconds Boot0000* Diskette Drive(device:0) Boot0001* CD-ROM Drive(device:FF) Boot0002* Hard Drive(Device:80)/HD(Part1,Sig00112233) Boot0003* PXE Boot: MAC(00D0B7C15D91) Boot0004* Linux

This shows:

· BootCurrent - the boot entry used to start the currently run- ning system

· BootOrder - the boot order as would appear in the boot man- ager. The boot manager tries to boot the first active entry in this list. If unsuccessful, it tries the next entry, and so on.

· BootNext - the boot entry which is scheduled to be run on next boot. This supercedes BootOrder for one boot only, and is deleted by the boot manager after first use. This allows you to change the next boot behavior without changing BootOrder.

· Timeout - the time in seconds between when the boot manager appears on the screen until when it automatically chooses the startup value from BootNext or BootOrder.

· Five boot entries (0000 - 0004), along with the active/inac- tive flag (* means active) and the name displayed on the screen.


CREATING A NEW BOOT OPTION An OS installer would call efibootmgr -c. This assumes that /boot/efi is your EFI System Partition, and is mounted at /dev/sda1. This cre- ates a new boot option, called "Linux", and puts it at the top of the boot order list. Options may be passed to modify the default behavior. The default OS Loader is elilo.efi.


CHANGING THE BOOT ORDER Assuming the configuration in Example #1, efibootmgr -o 3,4 could be called to specify PXE boot first, then Linux boot.


CHANGING THE BOOT ORDER FOR THE NEXT BOOT ONLY Assuming the configuration in Example #1, efibootmgr -n 4 could be called to specify that the Linux entry be taken on next boot.


DELETING A BOOT OPTION Assuming the configuration in Example #1, efibootmgr -b 4 -B could be called to delete entry 4 and remove it from the BootOrder.


CREATING NETWORK BOOT ENTRIES A system administrator wants to create a boot option to network boot (PXE). Unfortunately, this requires knowing a little more information about your system than can be easily found by efibootmgr, so youve got to pass additional information - the ACPI HID and UID values. These can generally be found by using the EFI Boot Manager (in the EFI envi- ronment) to create a network boot entry, then using efibootmgr to print it verbosely. Heres one example: Boot003* Acpi(PNP0A03,0)/PCI(5|0)/Mac(00D0B7F9F510) ACPI(a0341d0,0)PCI(0,5)MAC(00d0b7f9f510,0) In this case, the ACPI HID is "0A0341d0" and the UID is "0". For the zx2000 gigE, the HID is "222F" and the UID is "500". For the rx2000 gigE, the HID is "0002" and the UID is "100". You create the boot entry with: efibootmgr -c -i eth0 -H 222F -U 500 -L netboot

BUGS Please direct any bugs, features, patches, etc. to Matt Domsch <Matt_Domsch@dell.com>.

AUTHOR This man page was generated by dann frazier <dannf@debian.org> for the Debian GNU/Linux operating system, but may be used by others.

SEE ALSO elilo(1)

11 August 2005 EFIBOOTMGR(8)