BOOT(8)            OpenBSD System Manager's Manual (Zaurus)            BOOT(8)

NAME
     boot, boot.conf - zaurus-specific second-stage bootstrap

DESCRIPTION
     The main purpose of this program is to load the system kernel while deal-
     ing with the peculiarities of the zaurus machine.

     As described in 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.

     Basic operations include:

     o   Detecting and switching between multiple consoles.
     o   Loading kernels from any device supported by the primary bootstrap
         loader.
     o   Passing system parameters queried from the primary bootstrap loader
         to the kernel.
     o   Providing an interactive command line.

     The sequence of its operation is as follows: initialization, parsing the
     configuration file, then an interactive command line.  While at the com-
     mand line you have 5 seconds to type any commands, if needed.  If time
     expires, the kernel will be loaded according to the current variable set-
     tings (see the set command).  Each time a kernel load fails, the timeout
     is increased by one second.  The sequence of boot operations is as fol-
     lows:

     1.   Probe for console devices, which includes the (default) LCD+Keyboard
          console (cn0) and up to three serial consoles (com0 through com2)
          connected to the serial ports.  Display messages to the default con-
          sole about the devices found.

     2.   Probe for disk devices, and select the first disk with an i386-com-
          patible MBR and a valid OpenBSD primary partition.

     3.   If the file /etc/boot.conf exists on the root filesystem on the se-
          lected disk, open and parse it.  This file may contain any commands
          boot accepts at the interactive prompt.  Though default settings
          usually suffice, they can be changed here.

     4.   The header line

                >> OpenBSD/zaurus BOOT [x.xx]

          is displayed to the active console, where x.xx is the version number
          of the boot program, followed by the

                boot>

          prompt, which means you are in interactive mode and may enter com-
          mands.  If you do not, boot will proceed to load the kernel with the
          current parameters after the timeout period has expired.

     By default, boot attempts to load the kernel executable /bsd.  If it
     fails to find the kernel and no alternative kernel image has been speci-
     fied, the system will be unable to boot.

COMMANDS
     The following commands are accepted at the boot prompt:

     boot [image [-acds]]
              Boots the kernel image specified by image with any options giv-
              en.  Image specification consists of a pair device:filename; ei-
              ther or both can be omitted (`:' is not needed if both are omit-
              ted), in which case values from boot variables will be used.

              When selecting the device to boot from, boot makes no distinc-
              tion between SCSI and IDE type drives; they are detected as `hd'
              devices.  Therefore, to boot kernel /bsd from slice `a' on the
              first hard drive (irrespective of device type), specify ``boot
              hd0a:/bsd''.

              Note: Normally, the internal hard disk is designated by the
              device name `hd0'.  If a CF hard disk is present in the socket
              when the system starts, the internal hard disk is instead desig-
              nated by the prefix `hd1', and `hd0' will access the CF hard
              disk.

              -a   Causes the kernel to ask for the root device to use.

              -c   Causes the kernel to go into boot_config(8) before perform-
                   ing autoconf(4) procedures.

              -d   Causes the kernel to drop into ddb(4) at the earliest con-
                   venient point.

              -s   Causes the kernel to boot single-user.

     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.

     echo [args]
              Displays args on the console device.

     help     Prints a list of available commands and machine dependent com-
              mands, if any.

     ls [directory]
              Prints contents of the specified directory in long format in-
              cluding: attributes and file type, owner, group, size, filename.

     reboot   Returns control to the primary bootstrap loader.

     set [varname [value]]
              If invoked without arguments, prints a list of variables and
              their values.  If only varname is specified, displays contents
              of that variable.  If varname and value are both specified, sets
              that variable to the given value.  Variables include:

              addr     Address at which to load the kernel.
              debug    Debug flag if boot was compiled with DEBUG defined.
              device   Boot device name (e.g., hd0a).
              howto    Options to pass to the loaded kernel.
              image    File name containing the kernel image.
              timeout  Number of seconds boot will wait for human intervention
                       before booting the default kernel image.
              tty      Active console device name (e.g., cn0, com0, com1).

     stty [device [speed]]
              Displays or sets the speed for a console device.  If changing
              the baudrate for the currently active console, boot 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
              not for the active console, the baudrate is set for the next
              time you switch to a serial console.

              The default baudrate is 9600bps.

     time     Displays system time and date.

UPDATING BOOTBLOCKS
     Since the bootblocks actually live in a Linux flash filesystem, a rather
     obtuse method must currently be used to upgrade them.

           1.   Place zboot and zbsdmod.o onto an MS-DOS filesystem on a CF
                card, and then insert into the Zaurus.
           2.   Remove power from the Zaurus.
           3.   Unplug the battery.
           4.   Start holding down the `b' and `d' keys.
           5.   Wait 30 seconds, then re-insert the battery and power up the
                Zaurus.
           6.   When you see text start to appear on the Zaurus, release the
                `b' and `d' keys.
           7.   Login as root and perform the following steps:

                      # mount /dev/mtdblock2 /tmp
                      # cp /mnt/cf/z* /tmp/home/etc/rc.d
                      # reboot

                An SD card with an MS-DOS filesystem may be used instead, in
                which case the Linux pathname will be /mnt/card instead of
                /mnt/cf.

FILES
     /usr/mdec/zbsdmod.o  kernel module for the primary bootstrap loader that
                          must be loaded before the system bootstrap
     /usr/mdec/zboot      system bootstrap
     /etc/boot.conf       system bootstrap's startup file
     /bsd                 kernel image
     /bsd.rd              kernel image for installation/recovery

EXAMPLES
     Boot the default kernel:

           boot> boot

     Remove the 5 second pause at boot-time permanently, causing boot to load
     the kernel immediately without prompting:

           # echo "boot" > /etc/boot.conf

     Use serial console.  A null modem cable should connect the specified se-
     rial port to a terminal.  Useful for debugging.

           boot> set tty com0

     Invoke the serial console at every boot:

           # echo "set tty com0" > /etc/boot.conf

     Boot the kernel named /bsd from the second hard disk in ``User Kernel
     Configuration'' mode (see boot_config(8)).  This mechanism allows for the
     explicit enabling and disabling of devices during the current boot se-
     quence, as well as the modification of device parameters.  Once booted,
     such changes can be made permanent by using config(8)'s -e option.

           boot> boot hd1a:/bsd -c

SEE ALSO
     autoconf(4), ddb(4), boot_config(8), boot_zaurus(8), fdisk(8), reboot(8)

HISTORY
     This program was written by Michael Shalayeff for OpenBSD 2.1, and adapt-
     ed to zaurus by Uwe Stuehler for OpenBSD 3.7.

BUGS
     Non-IDE disks can not be used to load /etc/boot.conf or the kernel from
     them.

OpenBSD 4.7                      May 31, 2007                                4
