1.\" 2.\" Copyright (c) 2017-2018 Netflix, Inc. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd August 25, 2020 28.Dt EFIBOOTMGR 8 29.Os 30.Sh NAME 31.Nm efibootmgr 32.Nd manipulate the EFI Boot Manager 33.Sh SYNOPSIS 34.Nm 35.Op Fl v 36.Nm 37.Fl a 38.Fl b Ar bootnum 39.Nm 40.Fl A 41.Fl b Ar bootnum 42.Nm 43.Fl B 44.Fl b Ar bootnum 45.Nm 46.Fl c 47.Fl l Ar loader 48.Op Fl aD 49.Op Fl b Ar bootnum 50.Op Fl k Ar kernel 51.Op Fl L Ar label 52.Op Fl e Ar env 53.Nm 54.Fl E 55.Op Fl d 56.Op Fl p 57.Nm 58.Fl F 59.Nm 60.Fl f 61.Nm 62.Fl n 63.Fl b Ar bootnum 64.Nm 65.Fl N 66.Nm 67.Fl o Ar bootorder 68.Nm 69.Fl t Ar timeout 70.Nm 71.Fl T 72.Sh "DESCRIPTION" 73The 74.Nm 75program manipulates how UEFI Boot Managers boot the system. 76It can create and destroy methods for booting along with activating or 77deactivating them. 78It can also change the defined order of boot methods. 79It can create a temporary boot (BootNext) variable that references a 80boot method to be tried once upon the next boot. 81.Pp 82The UEFI standard defines how hosts may control what is used to 83bootstrap the system. 84Each method is encapsulated within a persistent UEFI variable, stored 85by the UEFI BIOS of the form 86.Cm Boot Ns Em XXXX 87(where XXXX are uppercase hexadecimal digits). 88These variables are numbered, each describing where to load the bootstrap 89program from, and whether or not the method is active (used for booting, 90otherwise the method will be skipped). 91The order of these methods is controlled by another variable, 92.Cm BootOrder . 93The currently booted method is communicated using 94.Cm BootCurrent . 95A global timeout can also be set. 96.Pp 97.Nm 98requires that the kernel module 99.Xr efirt 9 100module be present or loaded to get and set these 101non-volatile variables. 102.Pp 103The following options are available: 104.Bl -tag -width Ds 105.It Fl a -activate 106Activate the given 107.Ar bootnum 108boot entry, or the new entry when used with 109.Fl c . 110.It Fl A -deactivate 111Deactivate the given 112.Ar bootnum 113boot entry. 114.It Fl b -bootnum Ar bootnum 115When creating or modifying an entry, use 116.Ar bootnum 117as the index. 118When creating a new entry, fail if it already exists. 119.It Fl B -delete 120Delete the given 121.Ar bootnum 122boot entry. 123.It Fl c -create 124Create a new 125.Cm Boot 126variable (aka method or entry). 127.It Fl D -dry-run 128Process but do not change any variables. 129.It Fl E -esp 130Print the 131.Fx 132path to the ESP device, derived from the EFI variables 133.Va BootCurrent 134and 135.Va BootXXXX . 136This is the ESP partition used by UEFI to boot the current 137instance of the system. 138If 139.Fl d -device-path 140is specified, the UEFI device path to the ESP is reported instead. 141If 142.Fl p -unix-path 143is specified, the mount point of the ESP is reported instead. 144.It Fl f -fw-ui , Fl F -no-fw-ui 145Set or clear the request to the system firmware to stop in its user 146interface on the next boot. 147.It Fl k -kernel Ar kernel 148The path to and name of the kernel. 149.It Fl l -loader Ar loader 150The path to and name of the loader. 151.It Fl L -label Ar label 152An optional description for the method. 153.It Fl n -bootnext 154Set 155.Ar bootnum 156boot entry as the 157.Cm BootNext 158variable. 159.It Fl N -delete-bootnext 160Delete the 161.Cm BootNext 162optional variable. 163.It Fl o -bootorder Ar bootorder 164Set 165.Cm BootOrder 166variable to the given comma delimited set of 167.Ar bootnum Ns s . 168The numbers are in hex to match 169.Cm Boot Ns Em XXXX , 170but may omit leading zeros. 171.It Fl t -set-timeout Ar timeout 172Set the bootmenu timeout value. 173.It Fl T -del-timeout 174Delete the 175.Cm BootTimeout 176variable. 177.It Fl v -verbose 178Display the device path of boot entries in the output. 179.El 180.Sh Examples 181To display the current 182.Cm Boot 183related variables in the system: 184.Pp 185.Dl efibootmgr -v 186.Pp 187This will display the optional 188.Cm BootNext 189(if present), 190.Cm BootCurrent 191(currently booted method), followed by the optional 192.Cm Timeout 193value, any 194.Cm BootOrder 195that may be set, followed finally by all currently defined 196.Cm Boot 197variables, active or not. 198The verbose flag, 199.Pq Fl v , 200augments this output with the disk partition uuids, 201size/offset and device-path of the variable. 202The flag will also include any unreferenced (by BootOrder) variables. 203.Pp 204The 205.Nm 206program can be used to create new EFI boot variables. 207The following command may be used to create a new boot method, using 208the EFI partition mounted under 209.Pa /mnt , 210mark the method active, using 211the given loader and label the method 212.Qq FreeBSD-11 : 213.Pp 214.Dl efibootmgr -a -c -l /mnt/EFI/freebsd/loader.efi -L FreeBSD-11 215.Pp 216This will result in the next available bootnum being assigned to a 217new UEFI boot variable, and given the label 218.Qq FreeBSD-11 219such as: 220.Pp 221.Dl Boot0009 FreeBSD-11 222.Pp 223Note newly created boot entries are, by default, created inactive, hence 224the reason 225.Fl a 226flag is specified above so that it will be considered for booting. 227The active state is denoted by a '*' following the 228.Cm Boot Ns Em XXXX 229name in the output. 230They are also inserted into the first position of current 231.Cm BootOrder 232variable if it exists. 233They must first be set to active before being considered available to attempt 234booting from, else they are ignored. 235.Pp 236.Dl efibootmgr -B -b 0009 237.Pp 238Will delete the given boot entry Boot0009. 239.Pp 240To set the given boot entry active: 241.Pp 242.Dl efibootmgr -a -b 0009 243.Pp 244To set a given boot entry to be used as the 245.Cm BootNext 246variable, irrespective of its active state, use: 247.Pp 248.Dl efibootmgr -n -b 0009 249.Pp 250To set the 251.Cm BootOrder 252for the next reboot use: 253.Pp 254.Dl efibootmgr -o 0009,0003,... 255.Sh SEE ALSO 256.Xr efirt 9 , 257.Xr efivar 8 , 258.Xr gpart 8 , 259.Xr uefi 8 260.Sh STANDARDS 261The Unified Extensible Firmware Interface Specification is available 262from 263.Pa www.uefi.org . 264