4.3BSD - /usr/man/cat8/reboot.0

REBOOT(8)                                                            REBOOT(8)


NAME
       reboot - UNIX bootstrapping procedures

SYNOPSIS
       /etc/reboot [ -n ] [ -q ]

DESCRIPTION
       UNIX  is started by placing it in memory at location zero and transfer‐
       ring to the entry point.  Since the system is not  reenterable,  it  is
       necessary  to  read it in from disk or tape each time it is to be boot‐
       strapped.

       Rebooting a running system.  When a UNIX is running  and  a  reboot  is
       desired,  shutdown(8)  is  normally  used.   If there are no users then
       /etc/reboot can be used.  Reboot causes the  disks  to  be  synced  and
       allows  the  system to perform other shutdown activities such as resyn‐
       chronizing  hardware  time-of-day  clocks.   A  multi-user  reboot  (as
       described  below) is then initiated.  This causes a system to be booted
       and an automatic disk check to be  performed.   If  all  this  succeeds
       without incident, the system is then brought up for many users.

       Options to reboot are:

       -n     option avoids the sync.  It can be used if a disk or the proces‐
              sor is on fire.

       -q     reboots quickly and ungracefully, without shutting down  running
              processes first.

       Reboot  normally  logs the reboot using syslog(8) and places a shutdown
       record in the login accounting file /usr/adm/wtmp.  These  actions  are
       inhibited if the -n or -q options are present.

       Power fail and crash recovery.  Normally, the system will reboot itself
       at power-up or after crashes.  Provided the auto-restart is enabled  on
       the  machine  front  panel,  an automatic consistency check of the file
       systems will be performed, and  unless  this  fails,  the  system  will
       resume multi-user operations.

       Cold  starts.  These are processor type dependent.  On an 11/780, there
       are two floppy files for each disk  controller,  both  of  which  cause
       boots  from  unit  0 of the root file system of a controller located on
       mba0 or uba0.  One gives a single user shell, while the  other  invokes
       the  multi-user automatic reboot.  Thus these files are HPS and HPM for
       the single and multi-user boot from MASSBUS RP06/RM03/RM05  disks,  UPS
       and  UPM  for  UNIBUS  storage  module controller and disks such as the
       EMULEX SC-21 and AMPEX 9300 pair, or HKS and HKM for RK07 disks.  There
       is also a script for booting from the default device, which is normally
       a copy of one of the standard multi-user boot scripts, but which may be
       modified  to  perform  other  actions or to boot from a different unit.
       The situation on the 8600 is similar, with scripts loaded from the con‐
       sole RL02.

       Giving the command

              >>>BOOT HPM

       Would boot the system from (e.g.) an RP06 and run the automatic consis‐
       tency check as described in fsck(8).  (Note that it may be necessary to
       type  control-P  and  halt  the  processor to gain the attention of the
       LSI-11 before getting the >>> prompt.)  The command

              >>>BOOT ANY

       invokes a version of the boot program in a  way  which  allows  you  to
       specify  any system as the system to be booted.  It reads from the con‐
       sole a device specification (see below) followed immediately by a path‐
       name.

       The  scripts may be modified for local configuration if necessary.  The
       boot device type is set in register 10 as the device major number.  The
       flags and minor device are placed in register 11.  The register is used
       in four one-byte fields; from least to most significant, they are  boot
       flags  (as  defined in <sys/reboot.h>), disk partition, drive unit, and
       adaptor number (UNIBUS or MASSBUS as appropriate).

       On an 11/750, the reset button will boot from the  device  selected  by
       the front panel boot device switch.  In systems with RK07’s, position B
       normally selects the RK07 for boot.  This  will  boot  multi-user.   To
       boot from RK07 with boot flags you may specify

              >>>B/n DMA0

       where,  giving  a n of 1 causes the boot program to ask for the name of
       the system to be bootstrapped, giving a n of 2 causes the boot  program
       to  come  up  single user, and a n of 3 causes both of these actions to
       occur.  The ‘‘DM’’ specifies RK07, the  ‘‘A’’  represents  the  adaptor
       number  (UNIBUS  or  MASSBUS),  and the ‘‘0’’ is the drive unit number.
       Other disk types which may be used are DB (MASSBUS), DD (TU58), and  DU
       (UDA-50/RA  disk).   A  non-zero  disk  partition can be used by adding
       (partition times 1000 hex) to n.

       The 11/750 boot procedure uses the boot roms to load block 0 off of the
       specified  device.   The /usr/mdec directory contains a number of boot‐
       strap programs for the various disks which should be placed  in  a  new
       pack  automatically by newfs(8) when the ‘‘a’’ partition file system on
       the pack is created.

       On any processor, the boot program finds the corresponding file on  the
       given  device (vmunix by default), loads that file into memory location
       zero, and starts the program at the entry address specified in the pro‐
       gram  header  (after  clearing  off the high bit of the specified entry
       address).

       The file specifications used with “BOOT ANY” or “B/3” are of the form:

              device(unit,minor)

       where device is the type of the device to be searched, unit is 8 *  the
       mba  or  uba number plus the unit number of the disk or tape, and minor
       is the disk partition or tape file number.  Normal line editing charac‐
       ters  can  be  used  when typing the file specification.  The following
       list of supported devices may vary from installation to installation:
            hp   MASSBUS disk drive
            up   UNIBUS storage module drive
            ht   TE16,TU45,TU77 on MASSBUS
            mt   TU78 on MASSBUS
            hk   RK07 on UNIBUS
            ra   storage module on a UDA50
            rb   storage module on a 730 IDC
            rl   RL02 on UNIBUS
            tm   TM11 emulation tape drives on UNIBUS
            ts   TS11 on UNIBUS
            ut   UNIBUS TU45 emulator

       For example, to boot from a file system which starts at cylinder  0  of
       unit  0  of  a  MASSBUS  disk, type “hp(0,0)vmunix” to the boot prompt;
       “up(0,0)vmunix” would specify a  UNIBUS  drive,  “hk(0,0)vmunix”  would
       specify  an RK07 disk drive, “ra(0,0)vmunix” would specify a UDA50 disk
       drive, and “rb(0,0)vmunix” would specify a disk  on  a  730  IDC.   For
       tapes, the minor device number gives a file offset.

       On  an  11/750  with patchable control store, microcode patches will be
       installed by boot if the file psc750.bin exists  in  the  root  of  the
       filesystem from which the system is booted.

       In   an  emergency,  the  bootstrap  methods  described  in  the  paper
       ‘‘Installing and Operating 4.3bsd’’ can be used to boot from a  distri‐
       bution tape.

FILES
       /vmunix                 system code
       /boot                   system bootstrap
       /usr/mdec/xxboot        sector-0 boot block for 750, xx is disk type
       /usr/mdec/bootxx        second-stage boot for 750, xx is disk type
       /usr/mdec/installboot   program to install boot blocks on 750
       /pcs750.bin             microcode patch file on 750

SEE ALSO
       arff(8V),  crash(8V), fsck(8), halt(8), init(8), newfs(8), rc(8), shut‐
       down(8), syslogd(8)


4th Berkeley Distribution        May 28, 1986                        REBOOT(8)