NAME

reboot − reboot system or halt processor

SYNOPSIS

#include <sys/reboot.h>

reboot(howto, [ bootargs ] )
int howto;
char ∗bootargs;

DESCRIPTION

reboot() reboots the system, and is invoked automatically in the event of unrecoverable system failures.  howto is a mask of options passed to the bootstrap program.  The system call interface permits only RB_HALT or RB_AUTOBOOT to be passed to the reboot program; the other flags are used in scripts stored on the console storage media, or used in manual bootstrap procedures.  When none of these options (for instance RB_AUTOBOOT) is given, the system is rebooted from file /vmunix 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 then normally performed. 

The bits of howto are:

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

RB_ASKNAME
Interpreted by the bootstrap program itself, causing it to inquire as to what file should be booted.  Normally, the system is booted from the file /vmunix without asking. 

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

RB_DUMP A system core dump is performed before rebooting. 

RB_STRING The optional argument bootargs is passed to the bootstrap program.  See boot(8S) for details.  This option overrides RB_SINGLE but the same effect can be achieved by including −s as an option in bootargs.

Only the super-user may reboot() a machine. 

RETURN VALUES

On success, reboot() does not return.  On failure, it returns −1 and sets errno to indicate the error. 

ERRORS

EPERM The caller is not the super-user. 

FILES

/vmunix

SEE ALSO

panic(8S), halt(8), init(8), intro(8), reboot(8)

Solbourne Computer, Inc.  —  12 Dec 1990