1.\" $NetBSD: boot.cfg.5,v 1.28 2017/07/03 21:30:59 wiz Exp $ 2.\" 3.\" Copyright (c) 2007 Stephen Borrill 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. The name of the author may not be used to endorse or promote products 15.\" derived from this software without specific prior written permission 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25.\" INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27.\" 28.Dd April 25, 2014 29.Dt BOOT.CFG 5 30.Os 31.Sh NAME 32.Nm boot.cfg 33.Nd configuration file for /boot 34.Sh DESCRIPTION 35The file 36.Pa /boot.cfg 37is used to alter the behaviour of the standard boot loader described in 38.Xr boot 8 . 39Configuration changes include setting the timeout, choosing a console device, 40altering the banner text and displaying a menu allowing boot commands to be 41easily chosen. 42If a 43.Nm 44file is not present, the system will boot as normal. 45.Ss FILE FORMAT 46The format of the file is a series of lines containing keyword/value pairs 47separated by an equals sign 48.Pq Sq = . 49There should be no whitespace surrounding the equals sign. 50Lines beginning with a hash 51.Pq Sq # 52are comments and will be ignored. 53.Pp 54Some keywords can be present multiple times in the file to define additional 55items. 56Such keywords are noted below. 57.Bl -tag -width timeout 58.It Sy banner 59(may be present multiple times) 60The text from banner lines is displayed instead of the standard welcome text 61by the boot loader. 62Up to 10 lines can be defined. 63No special character sequences are recognised, so to specify a blank line, a 64banner line with no value should be given. 65.It Sy clear 66If nonzero, clear the screen before printing the banner. 67If zero, do not clear the screen (the default). 68.It Sy consdev 69Changes the console device to that specified in the value. 70Valid values are any of those that could be specified at the normal boot 71prompt with the consdev command. 72.It Sy default 73Used to specify the default menu item which will be chosen in the case of 74Return being pressed or the timeout timer reaching zero. 75The value is the number of the menu item as displayed. 76As described above, the menu items are counted from 1 in the order listed in 77.Nm . 78If not specified, the default value will be option 1, i.e. the first item. 79.It Sy format 80Changes how the menu options are displayed. 81Should be set to one of 82.Sq a 83for automatic, 84.Sq l 85for letters and 86.Sq n 87for numbers. 88If set to automatic (the default), menu options will be displayed numerically 89unless there are more than 9 options and the timeout is greater than zero. 90If there are more than 9 options with a timeout greater than zero and 91the format is set to number, only the first 9 options will be available. 92.It Sy load 93Used to load kernel modules, which will be passed on to the kernel for 94initialization during early boot. 95The argument is either the complete path and file name of the module to be 96loaded, or a symbolic module name. 97When the argument is not an absolute path, the boot loader will first 98attempt to load 99.Pa /stand/<machine>/<kernel_version>/modules/<name>/<name>.kmod . 100If that file does not exist, it will then attempt to load 101.Pa /<name> . 102May be used as many times as needed. 103.It Sy menu 104(may be present multiple times) 105Used to define a menu item to be displayed to the end-user at boot time 106which allows a series of boot commands to be run without further typing. 107The value consists of the required menu text, followed by a colon 108.Pq Sq \&: 109and then the desired command(s). 110Multiple commands can be specified separated by a semi-colon. 111If the specified menu text is empty 112(the colon appears immediately after the equals sign), 113then the displayed menu text is the same as the command. 114For example: 115.Bd -literal 116menu=Boot normally:boot 117menu=Boot single-user:boot -s 118menu=Boot with module foo:load /foo.kmod;boot 119menu=Boot with serial console:consdev com0;boot 120menu=:boot hd1a:netbsd -as 121.Ed 122.Pp 123Each menu item will be prefixed by an ascending number when displayed, 124i.e. the order in the 125.Nm 126file is important. 127.Pp 128Each command is executed just as though the user had typed it in 129and so can be any valid command that would be accepted at the 130normal boot prompt. 131In addition, 132.Dq Ic prompt 133can be used to drop to the normal boot prompt. 134.It Sy rndseed 135Takes the path to a random-seed file as written by the 136.Fl S 137flag to 138.Xr rndctl 8 139as an argument. 140This file is used to seed the kernel entropy pool 141.Xr rnd 9 142very early in kernel startup, so that high quality randomness is 143available to all kernel modules. 144This argument should be supplied 145before any 146.Dq Ic load 147commands that may load executable modules. 148.It Sy timeout 149If the value is greater than zero, this specifies the time in seconds 150that the boot loader will wait for the end-user to choose a menu item. 151During the countdown period, they may press Return to choose the default 152option or press a number key corresponding to a menu option. 153If any other key is pressed, the countdown will stop and the user will be 154prompted to choose a menu option with no further time limit. 155If the timeout value is set to zero, the default option will be booted 156immediately. 157If the timeout value is negative or is not a number, there will be no 158time limit for the user to choose an option. 159.It Sy userconf 160Passes a 161.Xr userconf 4 162command to the kernel at boot time. 163.El 164.Sh EXAMPLES 165Here is an example 166.Nm 167file: 168.Bd -literal -offset indent 169banner=Welcome to NetBSD 170banner================== 171banner= 172banner=Please choose an option from the following menu: 173menu=Boot normally:boot 174menu=Boot single-user:boot -s 175menu=Boot from second disk:boot hd1a: 176menu=Boot with module foo:load /foo.kmod;boot 177menu=Boot with modules foo and bar:load /foo.kmod;load /bar.kmod;boot 178menu=Boot Xen with 256MB for dom0:load /netbsd-XEN3_DOM0 console=pc;multiboot /usr/pkg/xen3-kernel/xen.gz dom0_mem=256M 179menu=Boot Xen with 256MB for dom0 (serial):load /netbsd-XEN3_DOM0 console=com0;multiboot /usr/pkg/xen3-kernel/xen.gz dom0_mem=256M console=com1 com1=115200,8n1 180menu=Boot Xen with dom0 in single-user mode:load /netbsd-XEN3_DOM0 -s;multiboot /usr/pkg/xen3-kernel/xen.gz dom0_mem=256M 181menu=Go to command line (advanced users only):prompt 182clear=1 183timeout=-1 184default=1 185userconf=disable ehci* 186# Always load ramdisk module 187load=/miniroot.kmod 188.Ed 189.Pp 190N.B. Xen counts serial ports from com1 upwards, but 191.Nx 192counts from com0, so the appropriate device name must be used. 193Please see the Xen with serial console example above. 194.Pp 195This will clear the screen and display: 196.Bd -literal -offset indent 197Welcome to NetBSD 198================= 199 200Please choose an option from the following menu: 201 202 1. Boot normally 203 2. Boot single-user 204 3. Boot from second disk 205 4. Boot with module foo 206 5. Boot with modules foo and bar 207 6. Boot Xen with 256 MB for dom0 208 7. Boot Xen with 256 MB for dom0 (serial) 209 8. Boot Xen with dom0 in single-user mode 210 9. Go to command line (advanced users only) 211 212Option [1]: 213.Ed 214.Pp 215It will then wait for the user to type 1, 2, 3, 4, 5, 6, 7, 8 or 9 followed by 216Return. 217Pressing Return by itself will run option 1. 218There will be no timeout. 219.Sh SEE ALSO 220.Xr boot 8 , 221.Xr boothowto 9 222.Sh HISTORY 223The 224.Nm 225file appeared in 226.Nx 5.0 . 227.Sh AUTHORS 228The 229.Nm 230extensions to 231.Xr boot 8 232were written by 233.An Stephen Borrill 234.Aq sborrill@NetBSD.org . 235.Sh BUGS 236Support for 237.Nm 238is currently for 239.Nx Ns /i386 240and 241.Nx Ns /amd64 242only. 243It is hoped that its use will be extended to other appropriate ports that 244use the 245.Xr boot 8 246interface. 247