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REBOOT(2)		  FreeBSD System Calls Manual		     REBOOT(2)

NAME
     reboot -- reboot system or	halt processor

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <unistd.h>
     #include <sys/reboot.h>

     int
     reboot(int	howto);

DESCRIPTION
     The reboot() system call reboots the system.  Only	the super-user may
     reboot a machine on demand.  However, a reboot is invoked automatically
     in	the event of unrecoverable system failures.

     The howto argument	is a mask of options; the system call interface	allows
     the following options, defined in the include file	<sys/reboot.h>,	to be
     passed to the new kernel or the new bootstrap and init programs.

     RB_AUTOBOOT   The default,	causing	the system to reboot in	its usual
		   fashion.

     RB_ASKNAME	   Interpreted by the bootstrap	program	itself,	causing	it to
		   prompt on the console as to what file should	be booted.
		   Normally, the system	is booted from the file
		   ``xx(0,0)kernel'', where xx is the default disk name, with-
		   out prompting for the file name.

     RB_DFLTROOT   Use the compiled in root device.  Normally, the system uses
		   the device from which it was	booted as the root device if
		   possible.  (The default behavior is dependent on the	abil-
		   ity of the bootstrap	program	to determine the drive from
		   which it was	loaded,	which is not possible on all systems.)

     RB_DUMP	   Dump	kernel memory before rebooting;	see savecore(8)	for
		   more	information.

     RB_HALT	   the processor is simply halted; no reboot takes place.
		   This	option should be used with caution.

     RB_POWEROFF   After halting, the shutdown code will do what it can	to
		   turn	off the	power.	This requires hardware support.

     RB_INITNAME   An option allowing the specification	of an init program
		   (see	init(8)) other than /sbin/init to be run when the sys-
		   tem reboots.	 This switch is	not currently available.

     RB_KDB	   Load	the symbol table and enable a built-in debugger	in the
		   system.  This option	will have no useful function if	the
		   kernel is not configured for	debugging.  Several other
		   options have	different meaning if combined with this
		   option, although their use may not be possible via the
		   reboot() system call.  See ddb(4) for more information.

     RB_NOSYNC	   Normally, the disks are sync'd (see sync(8))	before the
		   processor is	halted or rebooted.  This option may be	useful
		   if file system changes have been made manually or if	the
		   processor is	on fire.

     RB_RDONLY	   Initially mount the root file system	read-only.  This is
		   currently the default, and this option has been deprecated.

     RB_SINGLE	   Normally, the reboot	procedure involves an automatic	disk
		   consistency check and then multi-user operations.
		   RB_SINGLE prevents this, booting the	system with a single-
		   user	shell on the console.  RB_SINGLE is actually inter-
		   preted by the init(8) program in the	newly booted system.

     When no options are given (i.e., RB_AUTOBOOT is used), the	system is
     rebooted from file	``kernel'' in the root file system of unit 0 of	a disk
     chosen in a processor specific way.  An automatic consistency check of
     the disks is normally performed (see fsck(8)).

RETURN VALUES
     If	successful, this call never returns.  Otherwise, a -1 is returned and
     an	error is returned in the global	variable errno.

ERRORS
     [EPERM]		The caller is not the super-user.

SEE ALSO
     crash(8), halt(8),	init(8), reboot(8), savecore(8)

HISTORY
     The reboot() system call appeared in 4.0BSD.

BUGS
     The HP300 implementation supports neither RB_DFLTROOT nor RB_KDB.

FreeBSD	10.1			 June 4, 1993			  FreeBSD 10.1

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | HISTORY | BUGS

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