AUTOBOOT(M) XENIX System V AUTOBOOT(M)
Name
autoboot - Automatically boots the system.
Description
The system can be set up to go through the boot stages
automatically (as defined in /etc/default/boot when the
computer is turned on (booted), provided no key is pressed
at the boot(HW) prompt.
If boot times out and LOADXENIX=YES, then XENIX is passed
the word ``auto'' in its boot string and init(M), fsck(C),
and asktime(C) are passed an -a flag.
The autoboot procedure checks the file /etc/default/boot for
instructions on autobooting:
LOADXENIX=YES or NO Whether or not boot(HW) times out
and loads . boot looks for this
variable in the /etc/default/boot
file on its default device.
FSCKFIX=YES or NO Whether or not fsck(C) fixes any
root system problems by itself.
If the variable is set at YES,
then fsck(C) is run on the root
filesystem with the -rr flag.
MULTIUSER=YES or NO Whether or not init(M) invokes
sulogin or proceeds to multiuser
mode.
PANICBOOT=YES or NO Whether or not the system reboots
after a panic(). This variable
is read from /etc/default/boot by
init.
RONLYROOT=YES or NO Whether or not the root
filesystem is mounted readonly.
This must be used only during
installation, and not for a
normal boot. It will effectively
prevent writing to the
filesystem.
DEFBOOTSTR=bootstring Set default bootstring to
bootstring. This is the string
used by boot when the user
presses <RETURN> only to the
``boot:'' prompt, or when boot
times out.
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AUTOBOOT(M) XENIX System V AUTOBOOT(M)
SYSTTY=x If x is zero (0), the system
console device is set to the
serial adapter at COM. If x is
one (1), the system console is
set to the main display adapter.
If either the /etc/default/boot file or the variable needed
cannot be found, the variable is assumed to be NO. However,
if the filesystem cannot be found, PANICBOOT is YES.
The /etc/default/boot file is shipped with the following
default figuration:
LOADXENIX=YES
FSCKFIX=YES
MULTIUSER=YES
PANICBOOT=NO
A scratch file is needed by fsck to check large filesystems.
The user is informed during the installation of XENIX if the
system needs a scratch file to fsck the root filesystem. If
necessary, the installation procedure creates the filesystem
/dev/scratch to write the fsck temporary file. fsck uses
the file named on the /etc/default/boot line:
SCRATCH=
as a scratch file. If the installation procedure creates
the scratch filesystem, the entry in the /etc/default/boot
is automatically made.
SCRATCH need only be specified if the root filesystem is
large enough to need a temporary file. If a file is
specfied, it is always passed to fsck when checking the root
filesystem, even if the system is booted manually. The only
exception is the first time is booted from the hard disk,
when the user must specify the scratch file. The file
specified as SCRATCH must not be on the filesystem being
checked by fsck. SCRATCH also can not be on an unmounted
filesystem.
If the XENIX mail system, mail(C), is installed on the
system, the output of the boot sequence is mailed to root.
Otherwise, the system administrator should check the file
/etc/bootlog for the boot sequence output. The output of
fsck(C) is temporarily saved in the file /dev/recover before
it is moved to /etc/bootlog and finally may be sent to the
system administrator via mail.
Other boot options which take affect during autoboot are
documented on the boot(HW) manual page.
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AUTOBOOT(M) XENIX System V AUTOBOOT(M)
Files
/etc/bootlog boot output log for autobooting systems
/etc/default/boot boot information file
/etc/rc instructions for entering multi-user
mode, includes mounting and checking
additional file systems
/dev/recover allows saving of fsck output
/dev/scratch temporary fsck file for large filesystems
See Also
boot(HW), fsck(C), init(M)
Notes
The utilities invoked during the boot procedure are passed
the -a flag and time out only when the system autoboots.
For example, asktime(C) times out after 30 seconds when the
system autoboots, but waits for a response from the user any
other time it is invoked.
The previous boot modes of AUTO=CLEAN, DIRTY, NEVER have
been retained for backwards compatibility, but are ignored
if any of the newer modes are present.
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