.\"	$OpenBSD: boot.8,v 1.8 2007/05/31 19:20:05 jmc 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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.Dd $Mdocdate: March 4 2008 $
.Dt BOOT 8 zaurus
.Os
.Sh NAME
.Nm boot ,
.Nm boot.conf
.Nd
zaurus-specific second-stage bootstrap
.Sh DESCRIPTION
The main purpose of this program is to load the system kernel while dealing
with the peculiarities of the zaurus machine.
.Pp
As described in
.Xr boot_zaurus 8 ,
this program is loaded by the primary bootstrap loader and provides a
convenient way to load the kernel.
This program acts as an enhanced boot monitor for zaurus systems, providing
a common interface for the kernel to start from.
.Pp
Basic operations include:
.Pp
.Bl -bullet -compact
.It
Detecting and switching between multiple consoles.
.It
Loading kernels from any device supported by the primary bootstrap loader.
.\" .It
.\" Loading kernels compressed by
.\" .Xr gzip 1 .
.It
Passing system parameters queried from the primary bootstrap loader to the
kernel.
.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
Probe for console devices, which includes the (default) LCD+Keyboard
console
.Pq Li cn0
and up to three serial consoles
.Pf ( Li com0
through
.Li com2 )
connected to the serial ports.
Display messages to the default console about the devices found.
.\" .It
.\" Detect memory.
.\" Conventional memory is detected by querying the BIOS.
.\" Extended memory is detected by probing page-by-page through the address
.\" space, rather than asking the BIOS; many BIOS's cannot report larger than
.\" 64M of memory.
.\" All memory found is reported to the default console device.
.It
Probe for disk devices, and select the first disk with an i386-compatible
MBR and a valid
.Ox
primary partition.
.It
If the file
.Pa /etc/boot.conf
exists on the root filesystem on the selected disk, 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.
.It
The header line
.Pp
.Dl >> OpenBSD/zaurus 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
When selecting the
.Ar device
to boot from,
.Nm
makes no distinction between SCSI and IDE type drives;
they are detected as
.Sq hd
devices.
Therefore, to boot kernel
.Pa /bsd
from slice
.Sq a
on the first hard drive
.Pq irrespective of device type ,
specify
.Dq boot hd0a:/bsd .
.Pp
.Em Note:
Normally, the internal hard disk is designated by the
.Ar device
name
.Sq hd0 .
If a CF hard disk is present in the socket when the system starts,
the internal hard disk is instead designated by the prefix
.Sq hd1 ,
and
.Sq hd0
will access the CF hard disk.
.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 clear
Clears the console screen.
This is useful if your bootstrap console doesn't scroll the screen
automatically when the cursor is in the bottom line.
.It echo Op Ar args
Displays
.Ar args
on the console device.
.It help
Prints a list of available commands and machine dependent
commands, if any.
.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.
Returns control to the primary bootstrap loader.
.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 fd0a ,
.Li hd0a ) .
.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 cn0 ,
.Li com0 ,
.Li com1 ) .
.El
.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 UPDATING BOOTBLOCKS
Since the bootblocks actually live in a Linux flash filesystem, a
rather obtuse method must currently be used to upgrade them.
.Pp
.Bl -enum -offset indent -compact
.It
Place
.Pa zboot
and
.Pa zbsdmod.o
onto an MS-DOS filesystem on a CF card, and then insert into the Zaurus.
.It
Remove power from the Zaurus.
.It
Unplug the battery.
.It
Start holding down the
.Sq b
and
.Sq d
keys.
.It
Wait 30 seconds, then re-insert the battery and power up the Zaurus.
.It
When you see text start to appear on the Zaurus, release the
.Sq b
and
.Sq d
keys.
.It
Login as root and perform the following steps:
.Bd -literal -offset indent
# mount /dev/mtdblock2 /tmp
# cp /mnt/cf/z* /tmp/home/etc/rc.d
# reboot
.Ed
.Pp
An SD card with an MS-DOS filesystem may be used instead, in which case
the Linux pathname will be
.Pa /mnt/card
instead of
.Pa /mnt/cf .
.El
.Sh FILES
.Bl -tag -width /usr/mdec/zbsdmod.o -compact
.It Pa /usr/mdec/zbsdmod.o
kernel module for the primary bootstrap loader that must be
loaded before the system bootstrap
.It Pa /usr/mdec/zboot
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
Use serial console.
A null modem cable should connect the specified serial port to a terminal.
Useful for debugging.
.Pp
.Dl boot> set tty com0
.Pp
Invoke the serial console at every boot:
.Pp
.Dl # echo \&"set tty com0\&" > /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 hd1a:/bsd -c
.Sh SEE ALSO
.\" .Xr gzip 1 ,
.Xr autoconf 4 ,
.Xr ddb 4 ,
.Xr boot_config 8 ,
.Xr boot_zaurus 8 ,
.Xr fdisk 8 ,
.\" .Xr installboot 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 ,
and adapted to zaurus by Uwe Stuehler for
.Ox 3.7 .
.Sh BUGS
Non-IDE disks can not be used to load /etc/boot.conf or
the kernel from them.