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REBOOT(2)		    BSD	System Calls Manual		     REBOOT(2)

     reboot -- reboot system or	halt processor

     Standard C	Library	(libc, -lc)

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

     reboot(int	howto, char *bootstr);

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

     howto is a	mask of	options; the system call interface allows the follow-
     ing options, defined in the include file <sys/reboot.h>, to be passed to
     the new kernel or the new bootstrap and init programs.  In	addition to
     the options described below, other	options	described in boothowto(9) may
     be	set, but such options may be ignored by	the system.

     Options can be combined together by OR'ing	them, eg.  RB_DUMP | RB_NOSYNC
     would be interpreted as "dump kernel memory before	rebooting and don't
     sync the disks".

     RB_AUTOBOOT     0x0000    The default, causing the	system to reboot in
			       its usual fashion.
     RB_ASKNAME	     0x0001    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)netbsd", where xx
			       is the default disk name, without prompting for
			       the file	name.
     RB_DUMP	     0x0100    Dump kernel memory before rebooting; see
			       savecore(8) for more information.
     RB_HALT	     0x0008    the processor is	simply halted; no reboot takes
			       place.  This option should be used with cau-
     RB_POWERDOWN    0x0808    This option is always used in conjunction with
			       RB_HALT,	and if the system hardware supports
			       the function, the system	will be	powered	off,
			       otherwise it has	no effect.
     RB_INITNAME     0x0010    An option allowing the specification of an init
			       program (see init(8)) other than	/sbin/init to
			       be run when the system reboots.	This switch is
			       not currently available.
     RB_KDB	     0x0040    Load the	symbol table and enable	a built-in de-
			       bugger in the system.  This option will have no
			       useful function if the kernel is	not configured
			       for debugging.  Several other options have dif-
			       ferent meaning if combined with this option,
			       although	their use may not be possible via the
			       reboot()	call.  See ddb(4) for more informa-
     RB_NOSYNC	     0x0004    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 pro-
			       cessor is on fire.
     RB_RDONLY	     0x0080    Initially mount the root	file system read-only.
			       This is currently the default, and this option
			       has been	deprecated.
     RB_SINGLE	     0x0002    Normally, the reboot procedure involves an au-
			       tomatic 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 interpreted
			       by the init(8) program in the newly booted sys-

			       When no options are given (i.e.,	RB_AUTOBOOT is
			       used), the system is rebooted from file ``net-
			       bsd'' 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)).
     RB_STRING	     0x0400    bootstr is a string passed to the firmware on
			       the machine, if possible, if this option	is
			       set.  Currently this is only implemented	on the
			       sparc and the sun3 ports.
     RB_USERCONF     0x1000    Initially invoke	the userconf(4)	facility when
			       the system starts up again, if it has been com-
			       piled into the kernel that is loaded.

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

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

     ddb(4), crash(8), halt(8),	init(8), reboot(8), savecore(8), boothowto(9)

     The reboot() function call	appeared in 4.0BSD.

     The RB_DFLTROOT option is now obsolete.

BSD			       September 4, 2009			   BSD


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