.\"	$OpenBSD: boot.8,v 1.1 2008/05/28 21:36:11 miod Exp $
.\"
.\" Copyright (c) 1997-2001 Michael Shalayeff
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\"
.Dd $Mdocdate: May 28 2008 $
.Dt BOOT 8 armish
.Os
.Sh NAME
.Nm boot ,
.Nm boot.conf
.Nd
armish-specific bootstrap
.Sh DESCRIPTION
The main purpose of this program is to load the system kernel.
.Pp
As described in
.Xr boot_armish 8 ,
this program is loaded by the
firmware
and provides a convenient way to load the kernel.
This program acts as an enhanced boot monitor for armish systems, providing
a common interface for the kernel to start from.
.Pp
Basic operations include:
.Pp
.Bl -bullet -compact
.It
Loading kernels from hard disk.
.It
Loading kernels compressed by
.Xr gzip 1 .
.It
Providing an interactive command line.
.El
.Pp
The sequence of its operation is as follows: initialization,
parsing the configuration file, then an interactive command line.
While at the command line you have 5 seconds to type any commands, if needed.
If time expires, the kernel will be loaded according to
the current variable settings (see the
.Nm set
command).
Each time a kernel load fails, the timeout is increased by one second.
The sequence of
.Nm
operations is as follows:
.Bl -enum
.It
If the file
.Pa /etc/boot.conf
.\" XXX BEWARE! wd0 only, so text change...
.\" exists on the filesystem
.\" .Nm
.\" was loaded from, open and parse it.
exists on the filesystem in slice
.Sq a
on the first disk drive
.Pq wd0 ,
open and parse it.
This file may contain any commands
.Nm
accepts at the interactive prompt.
Though default settings usually suffice, they can be changed here.
.\" XXX CHECK_SKIP_CONF is not defined...
.\" .Pp
.\" .Pa boot.conf
.\" processing can be skipped by holding down either Control key as
.\" .Nm
.\" starts.
.It
The header line
.Pp
.Dl >> OpenBSD/armish BOOT [x.xx]
.Pp
is displayed to the active console, where
.Ar x.xx
is the version number of the
.Nm
program, followed by the
.Pp
.Dl boot>
.Pp
prompt, which means you are in interactive mode and may enter commands.
If you do not,
.Nm
will proceed to load the kernel with the current parameters after the
timeout period has expired.
.El
.Pp
By default,
.Nm
attempts to load the kernel executable
.Pa /bsd .
If it fails to find the kernel and no alternative kernel image has
been specified, the system will be unable to boot.
.Sh COMMANDS
The following commands are accepted at the
.Nm
prompt:
.Bl -tag -width shorten
.It boot Op Ar image Op Fl acds
Boots the kernel image specified by
.Ar image
with any options given.
Image specification consists of a pair
.Ar device : Ns Ar filename ;
either or both can be omitted (`:' is not needed if both are omitted),
in which case values from
.Nm
variables will be used.
.Pp
The only bootable devices, at the moment, are IDE devices connected to
the internal controller;
they are detected as
.Sq wd
devices.
Therefore, to boot kernel
.Pa /bsd
from slice
.Sq a
on the first hard drive,
specify
.Dq boot wd0a:/bsd .
.Bl -tag -width _a_
.It Fl a
Causes the kernel to ask for the
.Nm root
device to use.
.It Fl c
Causes the kernel to go into
.Xr boot_config 8
before performing
.Xr autoconf 4
procedures.
.It Fl d
Causes the kernel to drop into
.Xr ddb 4
at the earliest convenient point.
.It Fl s
Causes the kernel to boot single-user.
.El
.It echo Op Ar args
Displays
.Ar args
on the console device.
.It help
Prints a list of available commands.
.It ls Op Ar directory
Prints contents of the specified
.Ar directory
in long format including: attributes and file type, owner, group,
size, filename.
.It reboot
Reboots the machine by initiating a warm boot procedure.
.It set Op Ar varname Op Ar value
If invoked without arguments, prints a list of variables and their values.
If only
.Ar varname
is specified, displays contents of that variable.
If
.Ar varname
and
.Ar value
are both specified, sets that variable to the given value.
Variables include:
.Pp
.Bl -tag -compact -width boothow
.It Nm addr
Address at which to load the kernel.
.It Nm debug
Debug flag if
.Nm
was compiled with DEBUG defined.
.It Nm device
Boot device name (e.g.,
.Li wd0a ,
.Li wd1a ) .
.It Nm howto
Options to pass to the loaded kernel.
.It Nm image
File name containing the kernel image.
.It Nm timeout
Number of seconds boot will wait for human intervention before
booting the default kernel image.
.\" .It Nm tty
.\" Active console device name (e.g.,
.\" .Li com0 ) .
.\" Currently, only the first serial port
.\" .Pq Li com0
.\" is supported for console on armish.
.El
.\" XXX ignored, so don't document it.
.\" .It stty Op Ar device Op Ar speed
.\" Displays or sets the
.\" .Ar speed
.\" for a console
.\" .Ar device .
.\" If changing the baudrate for the currently active console,
.\" .Nm
.\" offers you five seconds of grace time before committing the change
.\" to allow you to change your terminal's speed to match.
.\" If changing speed
.\" .Em not
.\" for the active console, the baudrate is set for the
.\" .Em next
.\" time you switch to a serial console.
.\" .Pp
.\" The default baudrate is 9600bps.
.It time
Displays system time and date.
.El
.Sh FILES
.Bl -tag -width /etc/boot.conf -compact
.It Pa /usr/mdec/boot
system bootstrap
.It Pa /etc/boot.conf
system bootstrap's startup file
.It Pa /bsd
kernel image
.It Pa /bsd.rd
kernel image for installation/recovery
.El
.Sh EXAMPLES
Boot the default kernel:
.Pp
.Dl boot> boot
.Pp
Remove the 5 second pause at boot-time permanently, causing
.Nm
to load the kernel immediately without prompting:
.Pp
.Dl # echo \&"boot\&" > /etc/boot.conf
.Pp
Boot the kernel named
.Pa /bsd
from the second hard disk in
.Dq User Kernel Configuration
mode (see
.Xr boot_config 8 ) .
This mechanism allows for the explicit enabling and disabling of devices
during the current boot sequence, as well as the modification
of device parameters.
Once booted, such changes can be made permanent by using
.Xr config 8 Ns 's
.Fl e
option.
.Pp
.Dl boot> boot wd1a:/bsd -c
.Sh SEE ALSO
.Xr gzip 1 ,
.Xr autoconf 4 ,
.Xr ddb 4 ,
.Xr boot_armish 8 ,
.Xr boot_config 8 ,
.Xr fdisk 8 ,
.Xr reboot 8
.Pp
RFC 1950 describes the zlib library interface.
.Pp
The official home page for the version of zlib used in this
operating system is at http://www.gzip.org/zlib/.
.Sh HISTORY
This program was written by Michael Shalayeff for
.Ox 2.1
on the i386 platform, and was later ported to the armish platform for
.Ox 4.0 .