efibootmgr8

Usage

Overview

The efibootmgr program manipulates how UEFI Boot Managers boot the system. It can create and destroy methods for booting along with activating or deactivating them. It can also change the defined order of boot methods. It can create a temporary boot (BootNext) variable that references a boot method to be tried once upon the next boot.

The UEFI standard defines how hosts may control what is used to bootstrap the system. Each method is encapsulated within a persistent UEFI variable, stored by the UEFI firmware of the form BootXXXX (where XXXX are uppercase hexadecimal digits). These variables are numbered, each describing where to load the bootstrap program from, and whether or not the method is active (used for booting, otherwise the method will be skipped). The order of these methods is controlled by another variable, BootOrder. The currently booted method is communicated using BootCurrent. A global timeout can also be set.

efibootmgr requires that the kernel module efirt(9) module be present or loaded to get and set these non-volatile variables.

The following options are available:

-a --activate

Activate the given bootnum boot entry, or the new entry when used with -c.

-A --deactivate

Deactivate the given bootnum boot entry.

-b --bootnum bootnum

When creating or modifying an entry, use bootnum as the index. When creating a new entry, fail if it already exists. For convenience, if bootnum is prefixed with “boot”, that prefix is ignored.

-B --delete

Delete the given bootnum boot entry.

-c --create

Create a new Boot variable (aka method or entry).

-D --dry-run

Process but do not change any variables.

-e --env

When creating a Boot variable, include a set of environment variables for the loader to set after parsing the command line. Variables are of the form “a=b” and separated by spaces. The argument should be quoted. appends these to the end of the Boot environment variable. Before processing anything else, loader.efi(8) will parse this area and set all variables found there.

-E --esp

Print the FreeBSD path to the ESP device, derived from the EFI variables BootCurrent and BootXXXX. This is the ESP partition used by UEFI to boot the current instance of the system. If -d --device-path is specified, the UEFI device path to the ESP is reported instead. If -p --unix-path is specified, the mount point of the ESP is reported instead.

-f --fw-ui, -F --no-fw-ui

Set or clear the request to the system firmware to stop in its user interface on the next boot.

-k --kernel kernel

The path to and name of the kernel.

-l --loader loader

The path to and name of the loader.

-L --label label

An optional description for the method.

-n --bootnext

Set bootnum boot entry as the BootNext variable.

-N --delete-bootnext

Delete the BootNext optional variable.

-o --bootorder bootorder

Set BootOrder variable to the given comma delimited set of bootnums. The numbers are in hex to match BootXXXX, but may omit leading zeros.

-t --set-timeout timeout

Set the bootmenu timeout value.

-T --del-timeout

Delete the BootTimeout variable.

-u --efidev unix-path

Displays the UEFI device path of unix-path.

-v --verbose

Display extra information on boot entries: device path, attributes, category and optional data.

Examples

To display the current Boot related variables in the system:

efibootmgr -v

This will display the optional BootNext (if present), BootCurrent (currently booted method), followed by the optional Timeout value, any BootOrder that may be set, followed finally by all currently defined Boot variables, active or not. The verbose flag, (-v), augments this output with the disk partition uuids, size/offset and device-path of the variable. The flag will also include any unreferenced (by BootOrder) variables.

The efibootmgr program can be used to create new EFI boot variables. The following command may be used to create a new boot method, using the EFI partition mounted under /boot/efi, mark the method active, using the given loader and label the method "FreeBSD-15":

efibootmgr -a -c -l /boot/efi/EFI/freebsd/loader.efi -L FreeBSD-15

This will result in the next available bootnum being assigned to a new UEFI boot variable, and given the label "FreeBSD-15" such as:

Boot0009 FreeBSD-15

Note newly created boot entries are, by default, created inactive, hence the reason -a flag is specified above so that it will be considered for booting. The active state is denoted by a '*' following the BootXXXX name in the output. They are also inserted into the first position of current BootOrder variable if it exists. They must first be set to active before being considered available to attempt booting from, else they are ignored.

efibootmgr -B -b 0009

Will delete the given boot entry Boot0009.

To set the given boot entry active:

efibootmgr -a -b 0009

To set a given boot entry to be used as the BootNext variable, irrespective of its active state, use:

efibootmgr -n -b 0009

To set the BootOrder for the next reboot use:

efibootmgr -o 0009,0003,...