efibootmgr man page on ElementaryOS

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       efibootmgr — manipulate the EFI Boot Manager

       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]

       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:
	(link to URL http://developer.intel.com)


	      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.

       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
		 Don't 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	      "	 10 append extra variable args
		 from file (use - to  read  from  stdin).   Data  in  file  is
		 appended  as  command	line arguments to the boot loader com‐
		 mand, 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 cur‐
		       rently running system

		    ·  BootOrder - the boot order as would appear in the  boot
		       manager.	  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  automati‐
		       cally  chooses  the  startup  value  from  BootNext  or

		    ·  Five  boot  entries  (0000  -  0004),  along  with  the
		       active/inactive flag (* means active) and the name dis‐
		       played 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 creates 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


       Creating network boot entries

		 A system administrator wants to create a boot option to  net‐
		 work boot (PXE).  Unfortunately, this requires knowing a lit‐
		 tle more information about your system	 than  can  be	easily
		 found	by efibootmgr, so you've got to pass additional infor‐
		 mation - the ACPI HID and UID values.	These can generally be
		 found	by using the EFI Boot Manager (in the EFI environment)
		 to create a network boot  entry,  then	 using	efibootmgr  to
		 print it verbosely.  Here's one example:
		      Boot003*	 Acpi(PNP0A03,0)/PCI(5|0)/Mac(00D0B7F9F510)

		 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

       Please  direct  any  bugs,  features,  patches,	etc.  to  Matt	Domsch

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



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