4.3BSD-UWisc/man/cat8/reboot.8
REBOOT(8) UNIX Programmer's Manual 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
transferring 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 bootstrapped.
Rebooting a running system. When a UNIX is running and a
reboot is desired, _s_h_u_t_d_o_w_n(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 resynchronizing 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 processor is on fire.
-q reboots quickly and ungracefully, without shutting down
running processes first.
_R_e_b_o_o_t normally logs the reboot using _s_y_s_l_o_g(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 per-
formed, 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 sys-
tem 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
Printed 12/27/86 May 28, 1986 1
REBOOT(8) UNIX Programmer's Manual REBOOT(8)
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 modi-
fied to perform other actions or to boot from a different
unit. The situation on the 8600 is similar, with scripts
loaded from the console RL02.
Giving the command
>>>BOOT HPM
Would boot the system from (e.g.) an RP06 and run the
automatic consistency check as described in _f_s_c_k(8). (Note
that it may be necessary to type control-P and halt the pro-
cessor 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 console a device specification (see below)
followed immediately by a pathname.
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 <_s_y_s/_r_e_b_o_o_t._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
Printed 12/27/86 May 28, 1986 2
REBOOT(8) UNIX Programmer's Manual REBOOT(8)
contains a number of bootstrap programs for the various
disks which should be placed in a new pack automatically by
_n_e_w_f_s(8) when the ``a'' partition file system on the pack is
created.
On any processor, the _b_o_o_t program finds the corresponding
file on the given device (_v_m_u_n_i_x by default), loads that
file into memory location zero, and starts the program at
the entry address specified in the program 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 _d_e_v_i_c_e is the type of the device to be searched, _u_n_i_t
is 8 * the mba or uba number plus the unit number of the
disk or tape, and _m_i_n_o_r is the disk partition or tape file
number. Normal line editing characters can be used when
typing the file specification. The following list of sup-
ported 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 _b_o_o_t if the file _p_s_c_7_5_0._b_i_n 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 distribution tape.
FILES
/vmunix system code
Printed 12/27/86 May 28, 1986 3
REBOOT(8) UNIX Programmer's Manual REBOOT(8)
/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), shutdown(8), syslogd(8)
Printed 12/27/86 May 28, 1986 4