1.\" Copyright (c) 1999 Robert Nordier 2.\" All rights reserved. 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 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 20.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 21.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 22.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 23.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd February 21, 1999 28.Dt BOOT0CFG 8 29.Os 30.Sh NAME 31.Nm boot0cfg 32.Nd boot manager installation/configuration utility 33.Sh SYNOPSIS 34.Nm boot0cfg 35.Op Fl Bv 36.Op Fl b Ar boot0 37.Op Fl d Ar drive 38.Op Fl f Ar file 39.Op Fl m Ar mask 40.Op Fl o Ar options 41.Op Fl t Ar ticks 42.Ar disk 43.Sh DESCRIPTION 44The FreeBSD 45.Sq boot0 46boot manager permits the operator to select from which disk and which 47slice an i386 machine (PC) is booted. 48.Pp 49Note that what are referred to here as 50.Dq slices 51are typically called 52.Dq partitions 53in non-BSD documentation relating to the PC. Typically, only 54non-removable disks are sliced. 55.Pp 56The 57.Nm 58utility optionally installs the 59.Sq boot0 60boot manager on the specified 61.Ar disk ; 62and allows various operational parameters to be configured. 63.Pp 64On PCs, a boot manager typically occupies sector 0 of a disk, which is 65known as the Master Boot Record (MBR). The MBR contains both code (to 66which control is passed by the PC BIOS) and data (an embedded table of 67defined slices). 68.Pp 69The options are: 70.Bl -tag -width indent 71.It Fl B 72Install the 73.Sq boot0 74boot manager. This option causes MBR code to be replaced, but without 75affecting the embedded slice table. 76.It Fl v 77Verbose: display information about the slices defined, etc. 78.It Fl b Ar boot0 79Specify which 80.Sq boot0 81image to use. The default is /boot/boot0. 82.It Fl d Ar drive 83Specify the drive number used by the PC BIOS in referencing the drive 84which contains the specified 85.Ar disk . 86Typically this will be 0x80 for the first hard drive, 0x81 for the 87second hard drive, and so on; however any integer between 0 and 0xff 88is acceptable here. 89.It Fl f Ar file 90Specify that a backup copy of the preexisting MBR should be written to 91.Ar file . 92This file is created if it does not exist, and truncated if it does. 93.It Fl m Ar mask 94Specify slices to be enabled/disabled, where 95.Ar mask 96is an integer between 0 (no slices enabled) and 0xf (all four slices 97enabled). 98.It Fl o Ar options 99A comma-separated string of any of the following options may be 100specified (with 101.Dq no 102prepended as necessary): 103.Bl -tag -width indent 104.It packet 105Use the disk packet (BIOS Int 0x13 extensions) interface rather than 106the conventional (CHS) interface, when accessing disk-related BIOS 107services. The default is 108.Sq nopacket . 109.It setdrv 110Forces the drive containing the disk to be referenced using drive 111number definable by means of the -d option. The default is 112.Sq nosetdrv . 113.It update 114Allow the MBR to be updated by the boot manager. (The MBR may be 115updated to flag slices as 116.Sq active , 117and to save slice selection information.) This is the default; a 118.Sq noupdate 119option causes the MBR to be treated as read-only. 120.El 121.It Fl t Ar ticks 122Set the timeout value to 123.Ar ticks . 124(There are approximately 18.2 ticks per second.) 125.El 126.Sh SEE ALSO 127.Xr boot 8 , 128.Xr fdisk 8 . 129.Sh DIAGNOSTICS 130Exit status is 0 on success and >0 on error. 131.Sh AUTHORS 132.An Robert Nordier Aq rnordier@FreeBSD.org . 133.Sh BUGS 134Use of the 135.Sq packet 136option may cause 137.Sq boot0 138to fail, depending on the nature of BIOS support. 139.Pp 140Use of the 141.Sq setdrv 142option with an incorrect -d operand may cause the MBR to be written 143to the wrong disk. Be careful! 144