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32 .\" @(#)reboot.2 8.1 (Berkeley) 6/4/93
33 .\" $FreeBSD: src/lib/libc/sys/reboot.2,v 1.9.2.4 2001/12/14 18:34:01 ru Exp $
34 .\" $DragonFly: src/lib/libc/sys/reboot.2,v 1.4 2006/05/26 19:39:37 swildner Exp $
41 .Nd reboot system or halt processor
48 .Fn reboot "int howto"
52 Only the super-user may reboot a machine on demand.
53 However, a reboot is invoked
54 automatically in the event of unrecoverable system failures.
57 is a mask of options; the system call interface allows the following
58 options, defined in the include file
61 to the new kernel or the new bootstrap and init programs.
62 .Bl -tag -width RB_INITNAMEA
64 The default, causing the system to reboot in its usual fashion.
66 Interpreted by the bootstrap program itself, causing it to
67 prompt on the console as to what file should be booted.
68 Normally, the system is booted from the file
69 .Dq Em xx Ns No (0,0)kernel ,
72 is the default disk name,
73 without prompting for the file name.
75 Use the compiled in root device.
76 Normally, the system uses the device from which it was booted
77 as the root device if possible.
78 (The default behavior is dependent on the ability of the bootstrap program
79 to determine the drive from which it was loaded, which is not possible
82 Dump kernel memory before rebooting; see
86 the processor is simply halted; no reboot takes place.
87 This option should be used with caution.
89 After halting, the shutdown code will do what it can to turn
91 This requires hardware support.
93 An option allowing the specification of an init program (see
97 to be run when the system reboots.
98 This switch is not currently available.
100 Load the symbol table and enable a built-in debugger in the system.
101 This option will have no useful function if the kernel is not configured
103 Several other options have different meaning if combined
104 with this option, although their use may not be possible
110 for more information.
112 Normally, the disks are sync'd (see
114 before the processor is halted or rebooted.
115 This option may be useful if file system changes have been made manually
116 or if the processor is on fire.
118 Initially mount the root file system read-only.
119 This is currently the default, and this option has been deprecated.
121 Normally, the reboot procedure involves an automatic disk consistency
122 check and then multi-user operations.
124 prevents this, booting the system with a single-user shell
127 is actually interpreted by the
129 program in the newly booted system.
132 When no options are given (i.e.,
134 is used), the system is
137 in the root file system of unit 0
138 of a disk chosen in a processor specific way.
139 An automatic consistency check of the disks is normally performed
143 If successful, this call never returns.
144 Otherwise, a -1 is returned and an error is returned in the global
150 The caller is not the super-user.
161 function call appeared in
164 The HP300 implementation supports neither