xref: /netbsd-src/share/man/man8/boot.8 (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1.\"	$NetBSD: boot.8,v 1.9 2008/10/30 09:49:23 apb 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 October 30, 2008
36.Os
37.Dt BOOT 8
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.Pp
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, which is interpreted by the kernel in much the same way
57as the
58.Va howto
59argument passed to the
60.Xr reboot 2
61system call.
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 Xo Ic boot
70.Op Va device : Ns
71.Op Va filename
72.Op Fl 1234abcdmqsvxz
73.Xc
74The default
75.Va device
76will be set to the disk that the boot loader was
77loaded from.
78To boot from an alternate disk, the full name of the device should
79be given at the prompt.
80.Va device
81is of the form
82.Xo Va xd
83.Op Va N Ns Op Va x
84.Xc
85where
86.Va xd
87is the device from which to boot,
88.Va N
89is the unit number, and
90.Va x
91is the partition letter.
92.Pp
93The following list of supported devices may vary from installation to
94installation:
95.Pp
96.Bl -hang -compact
97.It hd
98Hard disks.
99.It fd
100Floppy drives.
101.El
102.Pp
103The default
104.Va filename
105is
106.Pa netbsd ;
107if the boot loader fails to successfully
108open that image, it then tries
109.Pa netbsd.gz
110(expected to be a kernel image compressed by gzip), followed by
111.Pa netbsd.old ,
112.Pa netbsd.old.gz ,
113.Pa onetbsd ,
114and finally
115.Pa onetbsd.gz .
116Alternate system images can be loaded by just specifying the name of the image.
117.Pp
118Options are:
119.Bl -tag -width xxx
120.It Fl 1
121Sets the machine-dependent flag
122.Sy RB_MD1
123in
124.Va boothowto .
125.It Fl 2
126Sets the machine-dependent flag
127.Sy RB_MD2
128in
129.Va boothowto .
130.It Fl 3
131Sets the machine-dependent flag
132.Sy RB_MD3
133in
134.Va boothowto .
135.It Fl 4
136Sets the machine-dependent flag
137.Sy RB_MD4
138in
139.Va boothowto .
140.It Fl a
141Sets the
142.Sy RB_ASKNAME
143flag in
144.Va boothowto .
145This causes the kernel to prompt for the root file system device,
146the system crash dump device, and the path to
147.Xr init 8 .
148.It Fl b
149Sets the
150.Sy RB_HALT
151flag in
152.Va boothowto .
153This causes subsequent reboot attempts to halt instead of rebooting.
154.It Fl c
155Sets the
156.Sy RB_USERCONF
157flag in
158.Va boothowto .
159This causes the kernel to enter the
160.Xr userconf 4
161device configuration manager as soon as possible during the boot.
162.Xr userconf 4
163allows devices to be enabled or disabled, and allows device locators
164(such as hardware addresses or bus numbers)
165to be modified before the kernel attempts to attach the devices.
166.It Fl d
167Sets the
168.Sy RB_KDB
169flag in
170.Va boothowto .
171Requests the kernel to enter debug mode, in which it
172waits for a connection from a kernel debugger; see
173.Xr ddb 4 .
174.It Fl m
175Sets the
176.Sy RB_MINIROOT
177flag in
178.Va boothowto .
179Informs the kernel that a mini-root file system is present in memory.
180.It Fl q
181Sets the
182.Sy AB_QUIET
183flag in
184.Va boothowto .
185Boot the system in quiet mode.
186.It Fl s
187Sets the
188.Sy RB_SINGLE
189flag in
190.Va boothowto .
191Boot the system in single-user mode.
192.It Fl v
193Sets the
194.Sy AB_VERBOSE
195flag in
196.Va boothowto .
197Boot the system in verbose mode.
198.It Fl x
199Sets the
200.Sy AB_DEBUG
201flag in
202.Va boothowto .
203Boot the system with debug messages enabled.
204.It Fl z
205Sets the
206.Sy AB_SILENT
207flag in
208.Va boothowto .
209Boot the system in silent mode.
210.El
211.It Ic consdev Va dev
212Immediately switch the console to the specified device
213.Va dev
214and reprint the banner.
215.Va dev
216must be one of
217.\" .Bl -item -width com[0123]kbd -offset indent -compact
218.Ar pc , com0 , com1 , com2 ,
219.Ar com3 , com0kbd , com1kbd , com2kbd ,
220.Ar com3kbd ,
221or
222.Ar auto .
223See
224.Sx Console Selection Policy
225in
226.Xr boot_console 8 .
227.It Ic dev Op Va device
228Set the default drive and partition for subsequent filesystem
229operations.
230Without an argument, print the current setting.
231.Va device
232is of the form specified in
233.Cm boot .
234.It Ic help
235Print an overview about commands and arguments.
236.\" .It Ic load Va module Op Va arguments
237.\" [i386 only]
238.It Ic ls Op Pa path
239Print a directory listing of
240.Pa path ,
241containing inode number, filename, and file type.
242.Pa path
243can contain a device specification.
244.\" .It Ic multiboot Va kernel Op Va arguments
245.\" [i386 only]
246.It Ic quit
247Reboot the system.
248.El
249.Pp
250In an emergency, the bootstrap methods described in the
251.Nx
252installation notes for the specific architecture
253can be used.
254.Sh FILES
255.Bl -tag -width /usr/mdec/bootxx_fstype -compact
256.It Pa /boot
257boot program code loaded by the primary bootstrap
258.\" .It Pa /boot.cfg
259.\" optional configuration file
260.\" (used only on i386 and amd64 architectures)
261.It Pa /netbsd
262system code
263.It Pa /netbsd.gz
264gzip-compressed system code
265.It Pa /usr/mdec/boot
266master copy of the boot program (copy to /boot)
267.It Pa /usr/mdec/bootxx_fstype
268primary bootstrap for filesystem type fstype, copied to the start of
269the
270.Nx
271partition by
272.Xr installboot 8 .
273.El
274.Sh SEE ALSO
275Architecture-specific
276.Xr boot 8
277manual pages,
278.Xr ddb 4 ,
279.Xr userconf 4 ,
280.\" .Xr boot.cfg 5 ,
281.Xr halt 8 ,
282.Xr installboot 8 ,
283.Xr reboot 8 ,
284.Xr rescue 8 ,
285.Xr shutdown 8
286.Sh BUGS
287The kernel file name must be specified before, not after, the boot options.
288Any
289.Ar filename
290specified after the boot options, e.g.:
291.Pp
292.Bd -unfilled -offset indent -compact
293.Cm boot -d netbsd.test
294.Ed
295.Pp
296is ignored, and the default kernel is booted.
297