efibootmgr [ -a ] [ -A ] [ -b XXXX ] [ -r | -y ] [ -B ] [ -c ] [ -d DISK ] [ -D ] [ -e 1|3|-1 ] [ -E NUM ] [ -g ] [ -i NAME ] [ -l NAME ] [ -L LABEL ] [ -m t|f ] [ -M X ] [ -n XXXX ] [ -N ] [ -o XXXX,YYYY,ZZZZ ... ] [ -O ] [ -p PART ] [ -q ] [ -t seconds ] [ -T ] [ -u ] [ -v ] [ -V ] [ -w ] [ -@ file ]
efibootmgr is a userspace application used to modify the Intel Extensible Firmware Interface (EFI) Boot Manager. This application can create and destroy boot entries, change the boot order, change the next running boot option, and more.
Details on the EFI Boot Manager are available from the EFI Specification, 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 /sys/firmware/efi/vars or /sys/firmware/efi/efivars/.
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
- BootCurrent - the boot entry used to start the currently 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 automatically chooses the startup value from BootNext or BootOrder.
- Five boot entries (0000 - 0004), along with the active/inactive 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 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 BootOrder.
CREATING NETWORK BOOT ENTRIES
A system administrator wants to create a boot option to network boot. You create the boot entry with: efibootmgr -c -i eth0 -L netboot [ -l '\filename.efi' ]
Please direct any bugs, features, patches, etc. to Peter Jones: https://github.com/rhinstaller/efibootmgr .