xref: /freebsd/share/man/man9/kern_reboot.9 (revision 81b22a98)
1.\"	$NetBSD: boot.9,v 1.2 1996/09/24 07:01:26 ghudson Exp $
2.\"
3.\" Copyright (c) 1997
4.\" 	Mike Pritchard.  All rights reserved.
5.\"
6.\" Copyright (c) 1994 Christopher G. Demetriou
7.\" All rights reserved.
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. All advertising materials mentioning features or use of this software
18.\"    must display the following acknowledgement:
19.\"      This product includes software developed by Christopher G. Demetriou
20.\"      for the NetBSD Project.
21.\" 3. The name of the author may not be used to endorse or promote products
22.\"    derived from this software without specific prior written permission
23.\"
24.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34.\"
35.\" $FreeBSD$
36.\"
37.Dd Sept 23, 2021
38.Dt KERN_REBOOT 9
39.Os
40.Sh NAME
41.Nm kern_reboot
42.Nd halt or reboot the system
43.Sh SYNOPSIS
44.In sys/types.h
45.In sys/systm.h
46.In sys/reboot.h
47.Ft void
48.Fn kern_reboot "int howto"
49.In sys/eventhandler.h
50.Fn EVENTHANDLER_REGISTER "shutdown_pre_sync" "shutdown_fn" "private" "priority"
51.Fn EVENTHANDLER_REGISTER "shutdown_post_sync" "shutdown_fn" "private" "priority"
52.Fn EVENTHANDLER_REGISTER "shutdown_final" "shutdown_fn" "private" "priority"
53.Sh DESCRIPTION
54The
55.Fn kern_reboot
56function handles final system shutdown, and either halts or reboots
57the system.
58The exact action to be taken is determined by the flags passed in
59.Fa howto
60and by whether or not the system has finished autoconfiguration.
61.Pp
62If the system has finished autoconfiguration,
63.Fn kern_reboot
64does the following:
65.Bl -enum -offset indent
66.It
67If this is the first invocation of
68.Fn kern_reboot
69and the
70.Dv RB_NOSYNC
71flag is not set in
72.Fa howto ,
73syncs and unmounts the system disks by calling
74.Xr vfs_unmountall 9 .
75.It
76Disables interrupts.
77.It
78If rebooting after a crash (i.e., if
79.Dv RB_DUMP
80is set in
81.Fa howto ,
82but
83.Dv RB_HALT
84is not), saves a system crash dump.
85.It
86Runs any shutdown hooks previously registered.
87.It
88Prints a message indicating that the system is about to be halted
89or rebooted.
90.It
91If
92.Dv RB_HALT
93is set in
94.Fa howto ,
95halts the system.
96Otherwise, reboots the system.
97.El
98.Pp
99If the system has not finished autoconfiguration,
100.Fn kern_reboot
101runs any shutdown hooks previously registered,
102prints a message, and halts the system.
103.Sh RETURN VALUES
104The
105.Fn kern_reboot
106function does not return.
107.Sh SEE ALSO
108.Xr reboot 2
109.Xr EVENTHANDLER 9
110.Xr vfs_unmountall 9
111