1.\" $NetBSD: boot.8,v 1.16 2017/06/22 16:46:52 flxd Exp $ 2.\" 3.\" Copyright (c) 1990, 1991 The Regents of the University of California. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the Systems Programming Group of the University of Utah Computer 8.\" Science Department. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.Dd April 8, 2003 35.Dt BOOT 8 pmax 36.Os 37.Sh NAME 38.Nm boot 39.Nd system bootstrapping procedures 40.Sh DESCRIPTION 41The 42.Nx 43kernel is started by placing it near the beginning of physical 44memory and transferring to the entry point. 45Since the system is not reenterable, 46it is necessary to read it in from disk or tape 47each time it is to be bootstrapped. 48.Ss Power fail and crash recovery 49Normally, the system will boot itself at power-up or after crashes. 50An automatic consistency check of the file systems will be performed, 51and unless this fails, the system will resume multi-user operations. 52.Ss Cold starts 53At power up, all DECstation ROMs consult the 54.Nm haltaction 55environment 56variable in EEPROM to determine whether or not to attempt to boot 57automatically. 58If this variable is set to 59.Sq h , 60the ROM prints a prompt on the console and 61waits for user commands. 62If set to 63.Sq b , 64the ROM attempts to autoboot. 65.Sh DECSTATION 2100 and 3100 66On the DECstation 2100 and 3100, the path used for automatic booting is 67stored in the 68.Nm bootpath 69environment variable. 70 The path is made up of a 71device type specifier (e.g., rz, tz, mop or tftp) followed by 72a triplet in the form (x,y,z), followed by a filename to load. 73.Pp 74Within the triplet, x is the controller (always 0), y is the SCSI id of 75the drive to 76boot from or 0 for net boots, and z is the partition to boot from 77(usually 0 for SCSI devices, always zero for network booting). 78For both disk and network boots, () may be specified instead of 79(0,0,0). 80.Pp 81The filename is optional for bootp/tftp and mop booting, since in 82these cases the network protocol can be used to determine which 83file to boot. 84When booting off the tape, no filename should be specified. 85When booting off of disk, the filename is optional but is usually specified. 86If no filename is specified when booting off disk, the following 87filenames are tried in order: 88.Nm netbsd.pmax , 89.Nm netbsd , 90.Nm netbsd.gz , 91.Nm netbsd.bak , 92.Nm netbsd.old , 93.Nm onetbsd , 94.Nm gennetbsd . 95Generally, the kernel is named 96.Nm netbsd . 97.Pp 98An example bootpath setting would be: 99.Dl Ic setenv bootpath rz(0,1,0)netbsd 100.Pp 101At the PROM prompt, the user may boot 102.Nx 103with either the 104.Nm auto 105or the 106.Nm boot 107command. 108If the 109.Nm auto 110command is used, the 111.Fl a 112argument is passed to the kernel, requesting a multi-user boot; otherwise 113the 114.Fl s 115argument is passed, requesting that 116.Nx 117boot to single user mode. 118.Pp 119When either the 120.Nm boot 121or the 122.Nm auto 123command is issued with no arguments, the kernel specified in the bootpath 124environment variable is booted. 125With the 126.Nm boot 127command, an alternative kernel may be specified 128with the 129.Fl f 130flag, followed by the path of the kernel to boot, as described above. 131For example: 132.Dl Ic boot -f rz(0,4,0)netbsd.new 133.Sh TURBOchannel DECstations 134On TURBOchannel machines (all DECstation 5000 models), the boot path 135is specified in the boot environment variable, along with any arguments 136to be passed to the kernel. 137Note that to specify boot arguments (e.g., 138.Fl a ) 139when setting the 140.Nm boot 141environment variable, the filename and arguments 142must be enclosed in quotes. 143For example: 144.Dl Ic setenv boot Dq Ic "3/rz4/netbsd -a" 145.Pp 146The device from which to boot is specified as the TURBOchannel slot 147number, a TURBOchannel-option-specific device name, and a path to the 148file to load, all separated by slashes. 149You can get a list of the 150devices installed in your TURBOchannel slots (as well as any built-in 151devices which appear as TURBOchannel slots) by typing the 152.Nm cnfg 153command 154at the boot prompt. 155You can get more detailed information about a specific 156TURBOchannel option by typing 157.Nm cnfg 158followed by the slot number of that 159option. 160.Pp 161For SCSI devices, the option-specific device identifier is either rz# for 162disks or tz# for tapes, where # is the SCSI id of the device. 163For network 164devices, the option-specific protocol identifier is either mop or tftp. 165Filename requirements are as for the DECstation 2100 and 3100. 166.Pp 167To start 168.Nx 169from the boot prompt, the 170.Nm boot 171command must be used. 172With no arguments, this simply boots the default 173kernel with the default arguments as set with 174.Nm setenv 175.Nm boot . 176If no boot environment variable is set or if an alternative kernel is to be 177booted, the path of that kernel may be specified after the boot command as 178described above, and any arguments may be passed similarly. 179For example: 180.Dl Ic boot 3/rz4/netbsd.new -a 181.Sh KERNEL ARGUMENTS 182The kernel supports the following arguments: 183.Bl -tag -width xxx -offset indent 184.It Li a 185Autoboot -- try and boot to multi-user mode without 186further input. 187.It Li m 188Use a miniroot already present in memory. 189.It Li n 190Prompt for the root file system device, the system crash dump 191device, and the path to 192.Xr init 8 . 193.It Li N 194Do not prompt for the root file system device, the system crash dump 195device, and the path to 196.Xr init 8 . 197If the configured-in devices are present, use them. 198.It Li s 199Boot only to single-user mode. 200.El 201.Pp 202Since DECstation PROMs also parse any arguments with a leading 203"-", and reject unrecognized options, arguments other than "a" or "s" 204should be specified after the kernel name with no leading "-". 205For example: 206.Dl Ic boot 3/rz4/netbsd \&ns 207.Sh SEE ALSO 208.Xr ddb 4 , 209.Xr halt 8 , 210.Xr init 8 , 211.Xr installboot 8 , 212.Xr rc 8 , 213.Xr reboot 8 , 214.Xr savecore 8 , 215.Xr shutdown 8 216.Sh HISTORY 217The 218.Nm 219command is 220.Ud 221