REBOOT(2)                                                            REBOOT(2)



NAME
       reboot - reboot system or halt processor

SYNOPSIS
       #include <sys/reboot.h>

       reboot(howto)
       int howto;

DESCRIPTION
       _R_e_b_o_o_t reboots the system, and is invoked automatically in the event of
       unrecoverable system failures.  _H_o_w_t_o 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 (e.g. RB_AUTOBOOT) is
       given,  the system is rebooted from file “vmunix” in the root file sys‐
       tem of unit 0 of a disk chosen in a processor specific way.   An  auto‐
       matic consistency check of the disks is then normally performed.

       The bits of _h_o_w_t_o 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 “xx(0,0)vmunix” without asking.

       RB_SINGLE
              Normally, the reboot procedure involves an automatic  disk  con‐
              sistency  check  and then multi-user operations.  RB_SINGLE pre‐
              vents the consistency check, rather simply  booting  the  system
              with  a  single-user  shell on the console.  RB_SINGLE is inter‐
              preted by the _i_n_i_t(8) program in the newly booted system.   This
              switch is not available from the system call interface.

       Only the super-user may _r_e_b_o_o_t a machine.

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

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

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

BUGS
       The notion of ‘‘console medium’’, among other things,  is  specific  to
       the VAX.



4th Berkeley Distribution         May 9, 1985                        REBOOT(2)