xref: /freebsd/usr.sbin/efibootmgr/efibootmgr.8 (revision 736dcdb75a9c2b478911f2e20536a99f0308aaad)

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.\" $FreeBSD$
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.Dd September 24, 2019
.Dt EFIBOOTMGR 8
.Os
.Sh NAME
.Nm efibootmgr
.Nd manipulate the EFI Boot Manager
.Sh SYNOPSIS
.Nm
.Op Fl v
.Nm
.Fl a
.Fl b Ar bootnum
.Nm
.Fl A
.Fl b Ar bootnum
.Nm
.Fl B
.Fl b Ar bootnum
.Nm
.Fl c
.Fl l Ar loader
.Op Fl aD
.Op Fl b Ar bootnum
.Op Fl k Ar kernel
.Op Fl L Ar label
.Nm
.Fl n
.Fl b Ar bootnum
.Nm
.Fl N
.Nm
.Fl o Ar bootorder
.Nm
.Fl t Ar timeout
.Nm
.Fl T
.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
.Cm Boot Ns Em XXXX .
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
.Cm BootOrder .
The currently booting method is communicated using
.Cm 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 Ds
.It Fl a -activate
Activate the given
.Ar bootnum
boot entry, or the new entry when used with
.Fl c .
.It Fl A -deactivate
Deactivate the given
.Ar bootnum
boot entry.
.It Fl b -bootnum Ar bootnum
When creating or modifying an entry, use
.Ar bootnum
as the index.
When creating a new entry, fail if it already exists.
.It Fl B -delete
Delete the given
.Ar bootnum
boot entry.
.It Fl c -create
Create a new
.Cm Boot
variable.
.It Fl D -dry-run
Process but do not change any variables.
.It Fl k -kernel Ar kernel
The path to and name of the kernel.
.It Fl l -loader Ar loader
The path to and name of the loader.
.It Fl L -label Ar label
An optional description for the entry.
.It Fl n -bootnext
Set
.Ar bootnum
boot entry as the
.Cm BootNext
variable.
.It Fl N -delete-bootnext
Delete the
.Cm BootNext
optional variable.
.It Fl o -bootorder Ar bootorder
Set
.Cm BootOrder
variable to the given comma delimited set of
.Ar bootnum Ns s .
The numbers are in hex to match
.Cm Boot Ns Em XXXX ,
but may omit leading zeros.
.It Fl t -set-timeout Ar timeout
Set the bootmenu timeout value.
.It Fl T -del-timeout
Delete the
.Cm BootTimeout
variable.
.It Fl v -verbose
Display the device path of boot entries in the output.
.El
.Sh Examples
To display the current
.Cm Boot
related variables in the system:
.Pp
.Dl efibootmgr [-v]
.Pp
This will display the optional
.Cm BootNext
bootnum,
.Cm BootCurrent ,
or currently booted bootnum, followed by the optional
.Cm Timeout
value, any
.Cm BootOrder
that may be set, followed finally by all currently defined
.Cm 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
.Pa /mnt ,
the given loader and a label
.Qq 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
.Qq 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
.Cm Boot Ns Em XXXX
name in the output.
They are also inserted into the first position of current
.Cm 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
.Cm BootNext
variable, irrespective of its active state, use:
.Pp
.Dl efibootmgr -n -b 0009
.Pp
To set the
.Cm BootOrder
for the next reboot use:
.Pp
.Dl efibootmgr -o 0009,0003,...
.Sh SEE ALSO
.Xr efivar 8 ,
.Xr gpart 8 ,
.Xr uefi 8