1.\" $NetBSD: reboot.2,v 1.5 1995/02/27 12:36:02 cgd Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. 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.\" @(#)reboot.2 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt REBOOT 2 38.Os BSD 4 39.Sh NAME 40.Nm reboot 41.Nd reboot system or halt processor 42.Sh SYNOPSIS 43.Fd #include <unistd.h> 44.Fd #include <sys/reboot.h> 45.Ft int 46.Fn reboot "int howto" 47.Sh DESCRIPTION 48.Fn Reboot 49reboots the system. 50Only the super-user may reboot a machine on demand. 51However, a reboot is invoked 52automatically in the event of unrecoverable system failures. 53.Pp 54.Fa Howto 55is a mask of options; the system call interface allows the following 56options, defined in the include file 57.Aq Pa sys/reboot.h , 58to be passed 59to the new kernel or the new bootstrap and init programs. 60.Bl -tag -width RB_INITNAMEA 61.It Dv RB_AUTOBOOT 62The default, causing the system to reboot in its usual fashion. 63.It Dv RB_ASKNAME 64Interpreted by the bootstrap program itself, causing it to 65prompt on the console as to what file should be booted. 66Normally, the system is booted from the file 67.Dq Em xx Ns No (0,0)netbsd , 68where 69.Em xx 70is the default disk name, 71without prompting for the file name. 72.It Dv RB_DFLTROOT 73Use the compiled in root device. 74Normally, the system uses the device from which it was booted 75as the root device if possible. 76(The default behavior is dependent on the ability of the bootstrap program 77to determine the drive from which it was loaded, which is not possible 78on all systems.) 79.It Dv RB_DUMP 80Dump kernel memory before rebooting; see 81.Xr savecore 8 82for more information. 83.It Dv RB_HALT 84the processor is simply halted; no reboot takes place. 85This option should be used with caution. 86.It Dv RB_INITNAME 87An option allowing the specification of an init program (see 88.Xr init 8 ) 89other than 90.Pa /sbin/init 91to be run when the system reboots. 92This switch is not currently available. 93.It Dv RB_KDB 94Load the symbol table and enable a built-in debugger in the system. 95This option will have no useful function if the kernel is not configured 96for debugging. 97Several other options have different meaning if combined 98with this option, although their use may not be possible 99via the 100.Fn reboot 101call. 102See 103.Xr kadb 4 104for more information. 105.It Dv RB_NOSYNC 106Normally, the disks are sync'd (see 107.Xr sync 8 ) 108before the processor is halted or rebooted. 109This option may be useful if file system changes have been made manually 110or if the processor is on fire. 111.It Dv RB_RDONLY 112Initially mount the root file system read-only. 113This is currently the default, and this option has been deprecated. 114.It Dv RB_SINGLE 115Normally, the reboot procedure involves an automatic disk consistency 116check and then multi-user operations. 117.Dv RB_SINGLE 118prevents this, booting the system with a single-user shell 119on the console. 120.Dv RB_SINGLE 121is actually interpreted by the 122.Xr init 8 123program in the newly booted system. 124.Pp 125When no options are given (i.e., 126.Dv RB_AUTOBOOT 127is used), the system is 128rebooted from file ``netbsd'' in the root file system of unit 0 129of a disk chosen in a processor specific way. 130An automatic consistency check of the disks is normally performed 131(see 132.Xr fsck 8 ) . 133.El 134.Sh RETURN VALUES 135If successful, this call never returns. 136Otherwise, a -1 is returned and an error is returned in the global 137variable 138.Va errno . 139.Sh ERRORS 140.Bl -tag -width Er 141.It Bq Er EPERM 142The caller is not the super-user. 143.El 144.Sh SEE ALSO 145.Xr kadb 4 , 146.Xr crash 8 , 147.Xr halt 8 , 148.Xr init 8 , 149.Xr reboot 8 , 150.Xr savecore 8 151.Sh BUGS 152The HP300 implementation supports neither 153.Dv RB_DFLTROOT 154nor 155.Dv RB_KDB . 156.Sh HISTORY 157The 158.Fn reboot 159function call appeared in 160.Bx 4.0 . 161