1 .\" Copyright (c) 1999 Robert Nordier
2 .\" All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
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.
13 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
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15 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
17 .\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
18 .\" OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
19 .\" OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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22 .\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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25 .\" $FreeBSD: src/usr.sbin/boot0cfg/boot0cfg.8,v 1.5.2.6 2003/03/12 22:08:13 trhodes Exp $
32 .Nd boot manager installation/configuration utility
48 boot manager permits the operator to select from which disk and
49 slice an i386 machine (PC) is booted.
51 Note that what are referred to here as
57 documentation relating to the PC.
58 Typically, only non-removable disks are sliced.
62 utility optionally installs the
64 boot manager on the specified
66 and allows various operational parameters to be configured.
68 On PCs, a boot manager typically occupies sector 0 of a disk, which is
69 known as the Master Boot Record (MBR).
70 The MBR contains both code (to which control is passed by the PC BIOS)
71 and data (an embedded table of defined slices).
74 .Bl -tag -width indent
79 This option causes MBR code to be replaced, without
80 affecting the embedded slice table.
82 Verbose: display information about the slices defined, etc.
90 Specify the drive number used by the PC BIOS in referencing the drive
91 which contains the specified
93 Typically this will be 0x80 for the first hard drive, 0x81 for the
94 second hard drive, and so on; however any integer between 0 and 0xff
97 Specify that a backup copy of the preexisting MBR should be written to
99 This file is created if it does not exist, and replaced if it does.
101 Specify slices to be enabled/disabled, where
103 is an integer between 0 (no slices enabled) and 0xf (all four slices
106 A comma-separated string of any of the following options may be
109 prepended as necessary):
110 .Bl -tag -width indent
112 Use the disk packet (BIOS Int 0x13 extensions) interface, as
113 as opposed to the legacy (CHS) interface, when doing disk I/O.
114 This allows booting above cylinder 1023, but requires specific
119 Forces the drive containing the disk to be referenced using drive
120 number definable by means of the -d option.
124 Allow the MBR to be updated by the boot manager.
125 (The MBR may be updated to flag slices as
127 and to save slice selection information.)
128 This is the default; a
130 option causes the MBR to be treated as read-only.
133 Set the default boot selection to
135 Values between 1 and 4 refer to slices; a value of 5 refers to the
136 option of booting from a second disk.
137 This would normally be used in conjunction with the
141 Set the timeout value to
143 (There are approximately 18.2 ticks per second.)
146 .Bl -tag -width /boot/boot0 -compact
153 The following is an example of a typical usage
156 utility to affect the next boot:
158 .Dl "boot0cfg -s 2 ad0"
165 .An Robert Nordier Aq rnordier@FreeBSD.org .
171 to fail, depending on the nature of BIOS support.
175 option with an incorrect -d operand may cause the MBR to be written