1.\" $NetBSD: boot.8,v 1.16 2017/02/18 21:47:11 wiz Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software written and contributed 7.\" to Berkeley by William Jolitz. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)boot_i386.8 8.2 (Berkeley) 4/19/94 34.\" 35.Dd August 16, 2014 36.Dt BOOT 8 37.Os 38.Sh NAME 39.Nm boot 40.Nd 41system bootstrapping procedures 42.Sh DESCRIPTION 43This document provides information on using common features in the 44.Nx 45boot loader. 46Additional information may be found in 47architecture-specific 48.Xr boot 8 49manual pages. 50.Ss Boot Protocol 51In the native 52.Nx 53boot protocol, options are passed from the boot loader 54to the kernel via flag bits in the 55.Va boothowto 56variable (see 57.Xr boothowto 9 ) . 58Some boot loaders may also support other boot protocols. 59.Ss Menu 60Some boot loaders may present a menu, which may be configured via 61.Xr boot.cfg 5 . 62.Ss Interactive mode 63In interactive mode, the boot loader will present a prompt, allowing 64input of these commands: 65.\" NOTE: much of this text is duplicated in architecture-specific 66.\" man pages (man8/man8.*/*boot*.8); 67.\" please try to keep all relevant files synchronized. 68.Bl -tag -width 04n -offset 04n 69.It Ic boot Oo Va device : Oc Ns Oo Va filename Oc Oo Fl 1234abcdmqsvxz Oc 70The default 71.Va device 72will be set to the disk that the boot loader was 73loaded from. 74To boot from an alternate disk, the full name of the device should 75be given at the prompt. 76.Va device 77is of the form 78.Xo Va xd 79.Op Va N Ns Op Va x 80.Xc 81where 82.Va xd 83is the device from which to boot, 84.Va N 85is the unit number, and 86.Va x 87is the partition letter. 88.Pp 89The following list of supported devices may vary from installation to 90installation: 91.Pp 92.Bl -hang -compact 93.It hd 94Hard disks. 95.It fd 96Floppy drives. 97.El 98.Pp 99The default 100.Va filename 101is 102.Pa netbsd ; 103if the boot loader fails to successfully 104open that image, it then tries 105.Pa netbsd.gz 106(expected to be a kernel image compressed by gzip), followed by 107.Pa netbsd.old , 108.Pa netbsd.old.gz , 109.Pa onetbsd , 110and finally 111.Pa onetbsd.gz . 112Alternate system images can be loaded by just specifying the name of the image. 113.Pp 114Options are: 115.Bl -tag -width xxx 116.It Fl 1 117Sets the machine-dependent flag 118.Sy RB_MD1 119in 120.Va boothowto . 121.It Fl 2 122Sets the machine-dependent flag 123.Sy RB_MD2 124in 125.Va boothowto . 126.It Fl 3 127Sets the machine-dependent flag 128.Sy RB_MD3 129in 130.Va boothowto . 131.It Fl 4 132Sets the machine-dependent flag 133.Sy RB_MD4 134in 135.Va boothowto . 136.It Fl a 137Sets the 138.Sy RB_ASKNAME 139flag in 140.Va boothowto . 141This causes the kernel to prompt for the root file system device, 142the system crash dump device, and the path to 143.Xr init 8 . 144.It Fl b 145Sets the 146.Sy RB_HALT 147flag in 148.Va boothowto . 149This causes subsequent reboot attempts to halt instead of rebooting. 150.It Fl c 151Sets the 152.Sy RB_USERCONF 153flag in 154.Va boothowto . 155This causes the kernel to enter the 156.Xr userconf 4 157device configuration manager as soon as possible during the boot. 158.Xr userconf 4 159allows devices to be enabled or disabled, and allows device locators 160(such as hardware addresses or bus numbers) 161to be modified before the kernel attempts to attach the devices. 162.It Fl d 163Sets the 164.Sy RB_KDB 165flag in 166.Va boothowto . 167Requests the kernel to enter debug mode, in which it 168waits for a connection from a kernel debugger; see 169.Xr ddb 4 . 170.It Fl m 171Sets the 172.Sy RB_MINIROOT 173flag in 174.Va boothowto . 175Informs the kernel that a mini-root file system is present in memory. 176.It Fl q 177Sets the 178.Sy AB_QUIET 179flag in 180.Va boothowto . 181Boot the system in quiet mode. 182.It Fl s 183Sets the 184.Sy RB_SINGLE 185flag in 186.Va boothowto . 187Boot the system in single-user mode. 188.It Fl v 189Sets the 190.Sy AB_VERBOSE 191flag in 192.Va boothowto . 193Boot the system in verbose mode. 194.It Fl x 195Sets the 196.Sy AB_DEBUG 197flag in 198.Va boothowto . 199Boot the system with debug messages enabled. 200.It Fl z 201Sets the 202.Sy AB_SILENT 203flag in 204.Va boothowto . 205Boot the system in silent mode. 206.El 207.It Ic consdev Va dev 208Immediately switch the console to the specified device 209.Va dev 210and reprint the banner. 211.Va dev 212must be one of 213.\" .Bl -item -width com[0123]kbd -offset indent -compact 214.Ar pc , com0 , com1 , com2 , 215.Ar com3 , com0kbd , com1kbd , com2kbd , 216.Ar com3kbd , 217or 218.Ar auto . 219See 220.Sx Console Selection Policy 221in 222.Xr x86/boot_console 8 . 223.It Ic dev Op Va device 224Set the default drive and partition for subsequent filesystem 225operations. 226Without an argument, print the current setting. 227.Va device 228is of the form specified in 229.Cm boot . 230.It Ic help 231Print an overview about commands and arguments. 232.\" .It Ic load Va module Op Va arguments 233.\" [x86 only] 234.It Ic ls Op Pa path 235Print a directory listing of 236.Pa path , 237containing inode number, filename, and file type. 238.Pa path 239can contain a device specification. 240.\" .It Ic multiboot Va kernel Op Va arguments 241.\" [x86 only] 242.It Ic quit 243Reboot the system. 244.\" .It Ic userconf Va command 245.\" [x86only] 246.El 247.Pp 248In an emergency, the bootstrap methods described in the 249.Nx 250installation notes for the specific architecture 251can be used. 252.Sh FILES 253.Bl -tag -width /usr/mdec/bootxx_fstype -compact 254.It Pa /boot 255boot program code loaded by the primary bootstrap 256.\" .It Pa /boot.cfg 257.\" optional configuration file 258.\" [x86 only] 259.It Pa /netbsd 260system code 261.It Pa /netbsd.gz 262gzip-compressed system code 263.It Pa /usr/mdec/boot 264master copy of the boot program (copy to /boot) 265.It Pa /usr/mdec/bootxx_fstype 266primary bootstrap for filesystem type fstype, copied to the start of 267the 268.Nx 269partition by 270.Xr installboot 8 . 271.El 272.Sh SEE ALSO 273Architecture-specific 274.Xr boot 8 275manual pages (such as 276.Xr emips/boot 8 , 277.Xr sparc64/boot 8 , 278.Xr x86/boot 8 ) , 279.Xr ddb 4 , 280.Xr userconf 4 , 281.\" .Xr boot.cfg 5 [x86 only] , 282.Xr halt 8 , 283.Xr installboot 8 , 284.Xr reboot 8 , 285.Xr rescue 8 , 286.Xr shutdown 8 , 287.Xr boothowto 9 288.Sh BUGS 289The kernel file name must be specified before, not after, the boot options. 290Any 291.Ar filename 292specified after the boot options, e.g.: 293.Pp 294.Bd -unfilled -offset indent -compact 295.Cm boot -d netbsd.test 296.Ed 297.Pp 298is ignored, and the default kernel is booted. 299