libc/sys/reboot.2

         Copyright (c) 1980 Regents of the University of California.
 All rights reserved. The Berkeley software License Agreement
 specifies the terms and conditions for redistribution.

 @(#)reboot.2 4.1 (Berkeley) 05/09/85

 REBOOT 2V 4/1/81
C 4  NAME
reboot - reboot system or halt processor
 SYNOPSIS
 #include <sys/reboot.h>
 reboot(howto)  int howto;
 DESCRIPTION
 Reboot is used to cause a system reboot, 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 (e.g. RB_AUTOBOOT) is given, the system is rebooted
from file \*(lqvmunix\*(rq in the root file system of unit 0
of a disk chosen in a processor specific way:
on the 11/780 it is specified by a line in the DEFBOO.CMD script on
the console floppy; on the 11/750 it is determined by the setting
of the front panel switch which picks the bootstrap device.
On the 11/730 it is determined by a file on the console casette.
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.
This 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 \*(lqxx(0,0)vmunix\*(rq without asking, where
 xx is determined by a code in register
 r10 (which is known as
 devtype) at entry to the bootstrap program. The code corresponds to the
major device number of the root file system, i.e. \*(lqmajor(rootdev)\*(rq.
Currently, the following values of
 devtype are understood:


.ns
0 hp rm03/rm05/rm80/rp06 massbus disk
1 -- unused
2 up unibus disks (emulex sc21 w/ cdc/ampex/fujitsu drives)
3 rk rk07 unibus disks


Thus if
 r10 contained a 2, the system

 up(0,0)vmunix.

would be booted.
This switch not available from the system call interface.

RB_SINGLE
Normally, the reboot procedure involves an automatic disk consistency
check and then multi-user operations. This prevents the consistency
check, rather simply booting the system with a single-user shell on
the console, from the file system specified by
 r10. This switch is interpreted by the
 init (8) program in the newly booted system.
This switch is not available from the system call interface.
 "SEE ALSO"
crash(8), halt(8), init(8), reboot(8)
 BUGS