BOOT(9)                      OpenBSD Kernel Manual                     BOOT(9)

NAME
     boot - halt or reboot the system

SYNOPSIS
     #include <sys/reboot.h>

     void
     boot(int howto);

DESCRIPTION
     The boot() function handles final system shutdown, and either halts or
     reboots the system.  The exact action to be taken is determined by the
     flags passed in howto and by whether or not the system has finished auto-
     configuration.

     If the system has finished autoconfiguration, boot() does the following:

           1.   Sets the boothowto system variable from the howto argument.

           2.   If this is the first invocation of boot() and the RB_NOSYNC
                flag is not set in howto, syncs and unmounts the system disks
                by calling vfs_shutdown(9) and sets the time of day clock by
                calling resettodr(9).

           3.   Disables interrupts.

           4.   If rebooting after a crash (i.e., if RB_DUMP is set in howto,
                but RB_HALT is not), saves a system crash dump.

           5.   Runs any shutdown hooks by calling doshutdownhooks(9).

           6.   Prints a message indicating that the system is about to be
                halted or rebooted.

           7.   If RB_HALT is set in howto, halts the system.  Otherwise, re-
                boots the system.

     If the system has not finished autoconfiguration, boot() runs any shut-
     down hooks by calling doshutdownhooks(9), prints a message, and halts the
     system (unless RB_USERREQ is specified, in which case the system will be
     halted if RB_HALT is given, and rebooted otherwise; see reboot(2) for
     more details).

SEE ALSO
     reboot(2), doshutdownhooks(9), resettodr(9), vfs_shutdown(9)

OpenBSD 4.0                    November 13, 1995                             1
