freebsd-dev/usr.sbin/efibootmgr/efibootmgr.8
Warner Losh 52467047aa Regularize the Netflix copyright
Use recent best practices for Copyright form at the top of
the license:
1. Remove all the All Rights Reserved clauses on our stuff. Where we
   piggybacked others, use a separate line to make things clear.
2. Use "Netflix, Inc." everywhere.
3. Use a single line for the copyright for grep friendliness.
4. Use date ranges in all places for our stuff.

Approved by: Netflix Legal (who gave me the form), adrian@ (pmc files)
2019-02-04 21:28:25 +00:00

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.\"
.\" Copyright (c) 2017-2018 Netflix, Inc.
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.\" $FreeBSD$
.\"
.Dd December 28, 2018
.Dt EFIBOOTMGR 8
.Os
.Sh NAME
.Nm efibootmgr
.Nd manipulate the EFI Boot Manager
.Sh SYNOPSIS
.Op Fl aAnNB
.Op Fl b Ar bootnum
.Op Fl t Ar timeout
.Op Fl T
.Op Fl o Ar bootorder
.Op Fl v
.Op Fl c l Ar loader [ Fl k Ar kernel ] [ Fl L Ar label ] [ Fl -dry-run ]
.Sh "DESCRIPTION"
.Nm
manipulates how UEFI Boot Managers boot the system.
Methods of booting can be created and destroyed.
Boot methods can be activated or deactivated.
The order of boot methods tried can be changed.
Temporary boot methods can override the usual booting methods.
.Pp
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 BIOS of the form
.Va BootXXXX .
These variables are numbered, describe where to load the bootstrap
program from, and whether or not the method is active.
The boot order of these methods is controlled by another variable
.Va BootOrder .
The currently booting method is communicated using
.Va BootCurrent .
A global timeout can also be set.
.Pp
.Nm
requires that the kernel efirt module be loaded to get and set these
non-volatile variables.
.Pp
The following options are available:
.Bl -tag -width 28m
.It Fl c Fl -create
Create a new Boot Variable
.It Fl l -loader Ar loader
The path to and name of the loader.
.It Fl k -kernel Ar kernel
The path to and name of the kernel.
.It Fl b -bootnum Ar bootnum
When creating or modifying an entry, use bootnum as the index.
When creating a new entry, fail if it already exists.
.It Fl L -label Ar label
An optional description for the entry.
.It Fl D -dry-run
Process but do not change any variables.
.It Fl B -delete
Delete the given bootnum boot entry.
.It Fl a -activate
Activate the given bootnum boot entry, or the new entry when used with -c.
.It Fl A -deactivate
Deactivate the given bootnum boot entry.
.It Fl n -bootnext
Set bootnum boot entry as the BootNext variable.
.It Fl N -delete-bootnext
Delete the BootNext optional variable.
.It Fl o -bootorder Ar 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.
.It Fl t -set-timeout Ar timeout
Set the bootmenu timeout value.
.It Fl T -del-timeout
Delete the BootTimeout variable.
.It Fl v -verbose
Display the device path of boot entries in the output.
.El
.Pp
.Sh Examples
.Pp
To display the current Boot related variables in the system:
.Pp
.Dl efibootmgr [-v]
.Pp
This will display the optional BootNext bootnum, BootCurrent,
or currently booted bootnum, 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 will augment this output with
the disk partition uuids, size/offset and device-path of the
variable.
.Pp
The
.Nm
program can be used to create new EFI boot variables. To create a new
boot var pointing to an installation with its EFI partition mounted
under /mnt, the given loader and a label "FreeBSD-11":
.Pp
.Dl efibootmgr -c -l /mnt/EFI/freebsd/loader.efi -L FreeBSD-11
.Pp
This will result in the next available bootnum being assigned to a
new UEFI boot variable, and given the label "FreeBSD-11" such as:
.Pp
.Dl Boot0009 FreeBSD-11
.Pp
Note newly created boot entries are created inactive. The active state is denoted
by an '*' 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.
.Pp
.Dl efibootmgr -B -b 0009
.Pp
Will delete the given boot entry Boot0009
.Pp
To set a given newly created boot entry active use:
.Pp
.Dl efibootmgr -a -b 0009
.Pp
To set a given boot entry to be used as the BootNext variable, irrespective
of its active state, use:
.Pp
.Dl efibootmgr -n -b 0009
.Pp
To set the BootOrder for the next reboot use:
.Pp
.Dl efibootmgr -o 0009,0003,...
.Pp
.Sh SEE ALSO
.Xr efivar 8 ,
.Xr uefi 8 ,
.Xr gpart 8