Freelog Special Edition 1: Linux/CD1.iso/doc/HOWTO/mini/Remote-Boot

Text File | 1998-10-14 | 121KB | 3,235 lines

  Linux Remote-Boot mini-HOWTO:      Configuring Remote-Boot
  Workstations    with Red-Hat Linux, DOS, Windows 3.1, Win¡
  dows 95 and Windows NT
  Marc Vuilleumier Stⁿckelberg, David Clerc and Sandro Viale
  v3.13, June 1998

  This document describes how to set up a very robust and secure server-
  based configuration for a cluster of PCs, allowing each client to
  choose at boot-time which operating system to run. The key of this
  configuration is a bootprom based program, which let the user choose
  at boot time one of several boot images. This configuration is appli¡
  cable using InCom TCP/IP Bootprom (add-on for most network cards) or
  any PXE-compliant Boot ROM (ready-to-use in most recent PC with built-
  in network cards).  The most up-to-date version of this document, with
  hypertext links to downloadable software and other related materials,
  can be found at the address http://cuiwww.unige.ch/info/pc/remote-
  boot/howto.html.  Linuxdoc-SGML, DVI and PostScript versions are
  available in the same directory.  If you are interested in getting
  info on further developpments, send an E-mail to
  [e-mail].
  ______________________________________________________________________

  Table of Contents











































  1. Disclaimer and Copyrights

  2. What has changed...

     2.1 ...since version 2.x ?
     2.2 ...since version 3.0 ?

  3. Introduction

     3.1 Boot ROM and Hard-disk
     3.2 The Network
     3.3 How it Works
     3.4 Related non-commercial documentations

  4. The Configuration How-To

     4.1 Server-side configuration
        4.1.1 Setting up DHCP
        4.1.2 Setting up a Proxy DHCP
        4.1.3 Setting up TFTP
     4.2 Client-side configuration
     4.3 Setting Up the Boot Process
        4.3.1 Discovering BpBatch
     4.4 Setting Up Linux
        4.4.1 Configuring the Client
        4.4.2 Testing the Configuration
        4.4.3 Building the Disk Image
        4.4.4 System Maintenance and Upgrades
     4.5 Setting up DOS 6 and Windows 3.1
        4.5.1 Building the Disk Image
        4.5.2 Adapting the configuration for other machines
        4.5.3 System Maintenance and Upgrades
     4.6 Setting up Windows 95
        4.6.1 Setting up a Stand-Alone Client
        4.6.2 Building the Disk Image
        4.6.3 Adapting the configuration for other Machines
        4.6.4 System Maintenance and Upgrades
     4.7 Setting up Windows NT
        4.7.1 Building the Disk Image
        4.7.2 System Maintenance and Upgrades
     4.8 Troubleshooting

  5. Remote-Boot Tools Reference Manual

     5.1 BpBatch, MrBatch and MrZip
        5.1.1 Command Line Arguments
        5.1.2 Syntax rules
        5.1.3 The Cache Filesystem
        5.1.4 Special variables
        5.1.5 Monitoring commands
        5.1.6 Control commands
        5.1.7 Keyboard-related commands
        5.1.8 Text output commands
        5.1.9 Graphics output commands
        5.1.10 Security-related commands
        5.1.11 Disk-related commands
        5.1.12 Boot commands
        5.1.13 National language support
        5.1.14 Commands specific to MrZip
     5.2 NoBreak.sys

  6. Special TFTP Servers

     6.1 Incom Enhanced TFTP Server
     6.2 Linux Enhanced TFTP Server
     6.3 The Security Gateway
     6.4 The Broadcast TFTP Server


  ______________________________________________________________________

  1.  Disclaimer and Copyrights

  This document and the related software are provided as is to the Linux
  and Internet community, with no form of warranty. Please note that
  some operations related in this document may destroy the content of
  your hard-disk. We assume no liability for any use, correct or not, of
  this document and of the related software.

  You are free to do anything you want with the remote-boot tools as
  long as you do not make money by selling them or by distributing them
  with a commercial product. If you want to commercialize a product
  derived from these tools, please contact the authors first to make a
  commercial agreement. These remote-boot tools will remain available
  for free forever, but we may authorize derived commercial tools.

  These provisions shall be interpreted under and in accordance with the
  laws of Switzerland, canton of Geneva. All disputes, defenses,
  controversies or claims arrising in conncetion with this document and
  the related software, shall be subject to the exclusive juridiction of
  the courts of the canton of Geneva, Switzerland.

  If you like this program, you can send us a Postcard and/or make a
  gift to the International Committee of the Red Cross (ICRC) or to the
  UNICEF.


  2.  What has changed...


  2.1.  ...since version 2.x ?

  To say it frankly, almost everything. The underlying concepts are the
  same, but the software part has been completly redesigned to overcome
  the limitations of previous versions and to make it easier to use. An
  highlight of the new features :

  ╖  All functions (bpmenu, bpclean, bpunzip) are encompassed in a
     single program.

  ╖  The program can run not only from the boot rom, but also under DOS,
     Windows 95 and Linux.

  ╖  The program can now restore images of FAT16, FAT32 and EXT2FS
     partitions. If someone want to write NTFS support, let me know...
     For now, NT users still have to stick to FAT16.

  ╖  The program can not only restore disk images but also add and patch
     individual files in order to customize the client behaviour.

  ╖  Disk images are not any more bound to 87 MB. They are now file-
     system independant archives.

  ╖  We provide a mean for automatically downloading a disk image to an
     arbitrary big number of clients at the same time (broadcast).

  ╖  You can now write your own secure boot script, that will determine
     the behaviour of the machine before the real boot.

  ╖  You can now boot any Linux kernel, without applying any patch. Its
     is also possible to provide a command line and a ramdisk image.

  ╖  You can authenticate users at boot time using a Unix, NT or Radius
     server and deny them any access to the machine.

  ╖  Full national language support is included.

  ╖  And many, many other new features...


     Is there a program for converting old archives to the new format ?
        No, because the internal format is radically different. But you
        can easily do the conversion by yourself:

        1. Boot an old image (unzip it to your disk)

        2. Remove calls to the old unzipreg utility and replace them by
           the adequate patch commands (it is very easy, see the
           detailed instructions below)

        3. Run the new mrzip program to create a new-style disk image

  2.2.  ...since version 3.0 ?

  Version 3.0 was the beta-release. A dozen of sites around the world
  have tested it during a month and given much of their time to help us
  finding bugs and to suggest enhancements. Thanks to all of them for
  their patience, and in particular to Maciek Uhlig, Dick Velders and
  Jeff Teeters.

  A few minor features have been added since 3.01, such as support for
  diskless Linux boot (by disabling the cache).

  Version 3.10 introduced compatibility with Intel's Wired for
  Management 1.1a NetPC standard. The tools now work with any PXE-
  compliant boot ROM (as are most on-board boot ROMs) available today.
  Thanks to InCom GmbH for giving us the PXE bootprom that permitted
  this developpment. We also succesfully tested the tools with the PXE
  Boot ROM that I found incidentally in my Dell computer with onboard
  network card (called LanDesk Service Agent).

  Version 3.11 to 3.12 added UNIX server-side tools (a PXE Proxy DHCP
  server for Solaris and Linux, and an enhanced TFTP server for Linux),
  as well as detailled informations on server-side setup and the PXE
  booting process.

  Version 3.13 added Advanced Power Management support (PowerOff
  command).


  3.  Introduction

  The configuration described here was developped since Summer 1996 at
  the CUI, University of Geneva. The Computer Science Department uses
  several servers and a number of PCs, which fall into two classes:

  ╖  computers devoted to students

  ╖  computers devoted to research and teaching assistants

     We developped the current configuration with the following aims:

  ╖  Every computer should be able to run under Linux, DOS, Windows 3.1,
     Windows 95 or Windows NT. One should be able to choose the desired
     operating system for each session.

  ╖  All softwares, including operating systems, should be take from the
     server, in order to facilitate the installations and upgrades.
  ╖  Clients computers should be able to run without any write-access on
     the server (for security reasons), except for their home directory.

  ╖  Client-side configuration should be reduced to its very minimum.
     Clients should automatically get their IP configuration parameters
     from the server, and this information should be located in a single
     file, used for all operating systems.

  ╖  Since almost every computer now has a hard-disk, clients should be
     able to take profit of it for reducing network load and as
     temporary storage space for the user.

  ╖  Users must have a login to be able to use any of the computers.

  ╖  The login should be the same for all operating system and should
     let the user access its unique home directory, common to all
     operating systems.

  ╖  Student (and secretary :-) computers should be fully cleaned up at
     each start. That is, the PC should always look like if it were just
     installed.

  ╖  Every computer has to be protected from virus attacks.

     These constraints lead us to base our configuration on bootprom
     tools. We first developped new tools for the excellent TCP/IP
     Bootprom from InCom GmbH.  Now that a standard for preboot
     execution environments as finally emerged, we ported the tools so
     that it now also works for any PXE-compliant bootprom. PXE boot
     roms, also called LanDesk Service Agent, are now distributed with
     almost all on-board network adapter.  For more info on PXE and
     Intel Wired for Management standard in general, read from
     http://www.intel.com/managedpc.


  3.1.  Boot ROM and Hard-disk

  Bootproms exist for quite a long time, but until recently, they were
  solely used with diskless computers. Since 1996, this How-to has been
  claiming that bootproms are even more interesting for computers which
  have a local harddisk, since they allow to take profit of both sides:

  ╖  A boot rom make the configurations more robust, since it ensure
     that the computer will always boot the same way, no matter any
     virus or partition table crash. It can be used, as we did, to
     cleanup the harddisk even before the operating system is loaded.

  ╖  A local harddisk make the configuration more efficient, since it
     can reduce the network trafic through caching, and allows for
     efficient swap.

     Today, we have the pleasure to see that all computer manufacturers
     have come to the same point and provide boot roms as part of new
     computer standards.

  Note that you can still use the tools described below in an old
  fashioned way, that is as a simple kernel/ramdisk loader, even for
  diskless computers. However, we do not encourage this use.


  3.2.  The Network

  The University of Geneva owns a class B domain, subdivided into
  several subnets. The CUI uses four subnets, among them one is
  dedicated to students.

  Originally, our PCs were concerned about two network protocols: IPX
  and IP.  On the IPX side, we used a single Novell Netware 3 server for
  sharing software and users files for DOS and Windows. On the IP side,
  we used a SUN server for sharing software and users partitions for
  Linux, with NFS.

  In our latest configuration, we do not any more use IPX. There is a
  single Unix server (which could be Linux as well as a SUN), sharing
  software and user files using NFS for Linux clients and using SMB
  (NetBIOS) over TCP/IP for Dos and Windows clients. In this way, we
  have a single home directory used by all operating systems.


  3.3.  How it Works


  1. When a client PC is turned on, it first performs the traditional
     system checks before the TCP/IP Bootprom or PXE Boot ROM takes the
     control.

  2. The bootprom issues a BOOTP/DHCP request in order to get its IP
     configuration parameters.

  3. If the server knows the PC issuing the request, it will send back a
     BOOTP/DHCP reply with informations such as the client's IP address,
     the default gateway, and which bootdisk image to use.

  4. In case of a PXE boot ROM, there might be some more exchanges
     between the client and the server to determine installation
     parameters.

  5. The bootprom then downloads the boot image from the server using
     the TFTP protocol. The boot image happens to be a small program
     called bpbatch, our boot-time batch file interpreter.

  6. The batch interpreter is started. At this time, it is almost alone
     in the computer memory. There is no operating system loaded, except
     the preboot execution environment (offered by the Boot ROM).

  7. The batch interpreter look in the BOOTP/DHCP reply for command-line
     options, and in particular for the name of the batch to execute.

  8. According to the instructions in the batch file, it will for
     instance:

     a. Load a national keyboard mapping

     b. Authenticate the user according to a remote server (Unix, Radius
        or Windows NT)

     c. Let the user choose between the available operating systems

     d. According to the operating system choosen, repartition the hard-
        disk and quick-format some partitions

     e. Check if an up-to-date compressed image of the selected OS is
        present at the end of the disk. If not, it download it using
        TFTP

     f. Uncompress the selected OS to the main partition

     g. If the selected OS is Linux, load a kernel and start it

     h. If the selected OS is DOS or Windows, simply let the computer
        boot on its fresh new hard-disk

     For DOS and Windows 3.1, we use the freely available Microsoft Lan¡
     Manager for DOS (search the network for the mirror nearest to you;
     the distribution consists of three files named disk1 to disk4) as
     SMB client. Microsoft LanManager supports dynamic configuration
     using DHCP. After logging in, the user is faced to DOS, and can
     start Windows 3.1 by typing the traditional win command. Note that
     at this point, DOS and Windows 3.1 appear to be installed locally.

     For Windows 95 and Windows NT, we also use Microsoft SMB client
     (called Client for the Microsoft Network), that supports dynamic
     configuration using DHCP. We reduce network load using Shared LAN
     Cache, a nice and powerful network-to-disk cache program.

     Students computers can be turned off the hard way at any time with¡
     out risks, since the hard disk is reinitialized at each start.

  For "safe" computers (ie. for assistants computers), once the computer
  has been booted once using the above described system, the boot script
  simply redirect the boot to the local hard-disk, without cleaning it
  again. This allow users to leave data on their local hard disk. But
  whenever the configuration gets corrupted, the user can simply choose
  from the boot menu in order to have a fresh installation.


  3.4.  Related non-commercial documentations

  This configuration has been successfully reproduced at several places
  around the world. A few people have written some hints and tricks that
  complement this How-To. If you did so and that your page is not
  already referenced in this documentation, please send an e-mail to
  [e-mail].  And if you experience
  problems while reproducing this configuration, have a look at these
  pages !

  ╖  http://www.katedral.se/system/elevsyst, by Johan Carlstedt of The
     Cathedral School of Uppsala, Sweden.  At this day, the
     configuration described at this place is still based on the
     previous version of the remote-boot tools. However, almost
     everything remains applicable, given a few changes.

  ╖  http://vitoria.upf.tche.br/~fred/, in portuguese, by Frederico
     Goldschmidt of the Passo Fundo University, Brasil.

  You can also send me your BpBatch script if you want me to include it
  in the sample scripts collection.


  4.  The Configuration How-To

  First, arrange to have the following two machines within arm's reach:

  ╖  the server, usually a Unix or Windows NT machine

  ╖  the client, a PC with a bootprom enabled, and nothing valuable on
     the hard disk.

     If you want to test the configuration but you do not yet have a
     bootprom, you can download the TCP/IP BootProm demo diskette from
     InCom GmbH at http://www.incom.de.  This diskette will make your
     computer behave like if it had a TCP/IP Bootprom plugged in.

  If you already have a Boot ROM, you need to enable it. If you are
  using Incom TCP/IP Bootprom, you can do that using a special program
  from your network card manufacturer. If you have a PXE Bootprom, you
  can do it simply from BIOS setup, by changing the default boot device.

  For student computers, we configured the boot on network first, and
  disabled hard-disk and floppy-disk boot. For assistant computers, we
  also configured network-boot first, but we allow hard-disk and floppy-
  disk boot.


  4.1.  Server-side configuration

  On the server, you will need the following services:

  1. A BOOTP/DHCP server

  2. May be a Proxy DHCP server

  3. A TFTP server

     Note for PXE Boot ROM users: We found after severals hours of
     tedious search that some (all ?) PXE Boot ROMs do not follow the IP
     protocol and discard all packets that have the Don't Fragment (DF)
     flag set.  That means, you will have to disable Path MTU Discovery
     on the server, or the Boot ROM will not see any of its packets. On
     Solaris, use ndd /dev/ip ip_path_mtu_discovery to see if you have
     it enabled and ndd -set /dev/ip ip_path_mtu_discovery 0 to disable
     it.  However, this fix only works for non-broadcast packets (ask
     SUN why...).  That means, it will work for TFTP but not for DHCP
     :-(.


  4.1.1.  Setting up DHCP

  The role of the DHCP server is to give to the client an IP address and
  to make it load the file named bpbatch.P from the TFTP server.  DHCP
  is a superprotocol over BOOTP. If you are using InCom TCP/IP Bootprom,
  you may live without DHCP (using an old BOOTP server).

  On Windows NT, you will probably use the native DHCP server.  If you
  are using InCom TCP/IP Bootprom, you will have to use a special trick
  to specify the boot file name (get more info from InCom WWW site). If
  you are using a PXE Bootrom, you will need a Proxy DHCP server, but no
  other trick is needed as the boot file name will be provided by the
  Proxy DHCP server.

  On Linux, the best choice is the standard DHCP server from the
  Internet Software Consortium. If you are using a PXE Bootrom, in
  addition to the usual options, you will need to add the following
  ones:

  ╖  option dhcp-class-identifier "PXEClient"

  ╖  option vendor-encapsulated-options ff;

  On Solaris, you can either use the Internet Software Consortium DHCP
  server (available on the Web), or use Solaris DHCP server (available
  since Solaris 2.5). However, as Solaris DHCP server does not seems to
  be able to insert a client class identifier in its DHCP offer, you
  must install a Proxy DHCP server. Morever, this Proxy DHCP server must
  reside on another computer since Solaris DHCP server locks the DHCP
  port.

  We suggest giving infinite lease time for remote-boot clients.  Don't
  forget that BOOTP/DHCP requests are bounded by subnets. If the client
  and the server do not reside on the same subnet, you should install a
  BOOTP/DHCP Relay agent on any computer between the two.  For now, just
  assume that both machines are on the same subnet.


  4.1.2.  Setting up a Proxy DHCP

  The role of the Proxy DHCP server is to overcome limitions of some
  DHCP servers and to provide PXE specific extensions. A proxy DHCP
  server only makes sense for a PXE Boot rom.

  As BpBatch itself is quite powerfull, you wont need to use any PXE
  specific DHCP extension (menus, etc.).  However, if your DHCP server
  is not able to show minimal PXE compliance, you will need a Proxy DHCP
  server or your PXE Boot ROM will not accept to go further.

  On Windows NT, you can try to use Intel WfM PDK (available from their
  web site), but it is not very easy to use. We rather suggest having a
  Linux machine on the subnet and using our small Proxy DHCP.  The major
  advantage of our Proxy DHCP Server for BpBatch is that our server will
  let you specify an option 155 vendor tag that will be interpreted by
  BpBatch as a command line.

  On Linux and Solaris, you can run our Proxy DHCP program, that simply
  takes as argument the TFTP server IP address, boot file name and
  optional arguments, and does everything for you.  If the DHCP port on
  the server is already requested by another daemon, the proxy DHCP
  server will run on port 4011. In this case, it is necessary that the
  other daemon on DHCP port answer a DHCP offer with client class
  PXEClient so that the PXE client knows that it must try on port 4011.

  If you want to understand better PXE extensions to DHCP, there is an
  extensive description available on Intel WWW site. However, be warned
  that the documents are quite confusing, as the protocol has been
  extended to a number of optional stages, in order to allow for a
  maximal flexibility. The key to understand it is that all what a PXE
  client needs is a complete enhanced DHCP answer. If it receives only a
  standard DHCP offer, it will look further until it gets

  1. a client class (T60) set to PXEClient

  2. vendor encapsulated options (T43) (possibly empty, ie. hex ff)

  3. a non-empty boot filename

     The PXE specific negociation ends as soon as all these infos are
     received, but can lead to a very complex process (install server
     discovery, etc.)  if some are missing.


  4.1.3.  Setting up TFTP

  The TFTP server is a very simple file server. In its basic version,
  TFTP use 512 bytes data blocks, which are quite inefficients.  InCom
  TCP/IP Bootprom and PXE Boot ROMs allow to use larger blocks (1408
  bytes), which speeds up transfers a lot. However, this can only work
  with an enhanced TFTP server.

  On Windows NT, we suggest using InCom enhanced TFTP server, available
  on their web site.

  On Linux, you can use our enhanced TFTP server, available at
  http://cuiwww.unige.ch/info/pc/remote-boot/soft/etftpd.tar.gz.

  On Solaris, you should use InCom enhanced TFTP serer, available on the
  utility disk provided with the TCP/IP Bootprom.

  If you prefer using a standard TFTP daemon, remove the P in all boot
  image name extensions, in order to tell the Bootprom to use only the
  standard TFTP port (This trick was introduced by InCom GmbH for the
  TCP/IP Bootprom. We still use it as an easy way to select the default
  TFTP port with PXE bootproms).


  4.2.  Client-side configuration

  First, we will do set up the part common to all operating systems, ie.
  the batch-file interpreter.  Then, for each operating system, we will
  go through the following steps:

  1. Setup a stand-alone client

  2. Save its configuration on the server

  3. Test it as a remote-boot client

  4. Adapt it so that it works for any similar client machine

     Once this is done, you will be able to setup any supplemental
     client just by plugging a Boot ROM in it (or buying a Wired for
     Management ready computer...) and adding one line in the DHCP
     configuration file.

  Our examples assume that you have a hard disk of 1.4 Gb or more.  If
  you have less, reduce the sizes of the partitions, but remember the
  you need to leave a few hundreds megabytes unallocated (that is, the
  last partition must not take up to the last cylinder) to leave free
  room for the special cache partition. Moreover, as the cache always
  starts at the cylinder following the last allocated cylinder, if you
  do not use the same total size for all your tests, you will have to
  download several times the same files (the cache will be automatically
  cleared).

  Never despair. If you can't get it to work, first look in the
  Troubleshooting section if your problem is not already solved (get the
  latest version from the Web).  If it still does not work, think about
  monitoring network traffic for network related problems (use tcpdump
  on Linux or snoop on Solaris). If you really cannot get it to work,
  you can send an E-mail to [e-mail] or
  [e-mail].  If your problem is strictly
  related with the remote-boot configuration and if we are not
  overflowed, we will try to solve your problem.


  4.3.  Setting Up the Boot Process

  Get the BpBatch software, either as .zip or as .tar.gz.  The
  executables are available at

  ╖  http://cuiwww.unige.ch/info/pc/remote-boot/soft/bpb-exe.zip

  ╖  http://cuiwww.unige.ch/info/pc/remote-boot/soft/bpb-exe.tar.gz

     The source code (Assembler and C) is also available on request.

  In the server /tftpboot directory, put the following three special
  boot images, which together make our pre-boot batch file interpreter:

  ╖  bpbatch.P, the dynamic loader (respect the uppercase !)

  ╖  bpbatch.ovl, the relocated interpreter

  ╖  bpbatch.hlp, the on-line help file

     Then add an entry in the DHCP configuration file for your client,
     with the boot file set to "bpbatch.P". Define a vendor option tag
     155 (decimal) with the value "-i" (on the standard DHCP server,
     this is done by the following command: option option-155 "-i";). It
     is interpreted by bpbatch as the command line, and -i stands for
     "interactive".

  Boot the client computer. You might shortly see

  ╖  The Boot ROM copyright

  ╖  The string DHCP while the client waits for a DHCP reply

  ╖  The string TFTP while the client waits for the first TFTP packet

  ╖  The string Loading BpBatch while the loader download the
     interpreter

  ╖  And finaly our banner, followed by a nice greather-than prompt

     Congratulations ! You have started the batch interpreter...  If you
     are curious about what you can do with it, continue reading the
     next section. If you are on a hurry, skip it and go directly
     install the operating system of your choice. If you have any doubt
     about a command within the interpreter, type help.

  Note that you can run the same interpreter within DOS and Linux by
  running the MrBatch program. There are a only very few differences
  (the Linux version do not have graphics support and the DOS version
  can only send BOOTP and TFTP requests if the BootProm is not hidden by
  the operating system).

  It may be a good idea to read now the section about the Syntax Rules
  of BpBatch, and in particular the paragraphs on File References and on
  The Cache Filesystem.  This will help you understand the examples.

  Once all operating systems will be set up, you will have to make a
  menu to let the user choose the one he wants. You should be able to
  discover by yourself how to make such a menu. All necessary commands
  are documented at the end of this document.


  4.3.1.  Discovering BpBatch

  Try to type LogVars. You should get about thirty variables listed.
  Roughly, the first are BpBatch settings, then come all parameters
  extracted from the BOOTP/DHCP reply, and the last variable is a list
  of disks sizes, in Megabytes.

  Type GetPartitions part, then LogVars again. There should be one more
  variable containing the list of defined partitions on your first hard-
  drive. Assuming that the first partition is either BIGDOS, FAT32 or
  LINUX-EXT2, try LogDir "{:1}" to get the content of the root
  directory, then LogDir "{:1}/usr" if there is an usr directory. You
  can even try LogTree "{:1}/etc" to get a directory tree.

  Put a GIF file (format GIF-87a, interlaced or not, but NOT GIF-89a) on
  your TFTP server. We will suppose that the file is named image.gif.
  You can copy it wherever you want with the following command: Copy
  "image.gif" "{:1}/temp/image.gif". Or you can use it directly from the
  server. Now type Logvars "V*" and look at the value of the VESA
  variable. If it is On, which is most probable, that means you have a
  VESA-compliant video adapter and you will be able to display the image
  with the following command: DrawGif "image.gif". The image should be
  on the upper left corner of the screen. You can draw it on another
  place by specifying X and Y coordinates after the image name. You can
  also draw text with DrawText 200 200 "Hello world" yellow. Or draw an
  empty window with DrawWindow 200 200 300 150. When you are tired of
  graphic mode, simply type CloseGraph.
  Now take a text editor, and create a file named test.bpb in the
  tftpboot directory with the following content:


       ______________________________________________________________________
       :again
       DrawWindow 150 200 400 160
       DrawText 155 204 "Identity check" white
       TextAttr Black LightGray
       At 15,20 Print "Username : "
       Input username 8
       At 17,20 Print "Password : "
       Getpasswd userpass 8
       if "$username" != "smith" goto again
       if not "$userpass" match-passwd "BpR8oiIlRR9bo" goto again
       #
       clear
       DrawWindow 200 200 150 100 green
       DrawText 205 204 "Congratulations" white
       DrawText 220 250 "You got it !" yellow
       WaitForKey 3
       CloseGraph
       interact
       ______________________________________________________________________




  In your BOOTP/DHCP configuration, change the option-155 from "-i" to
  "test", and reboot the client computer. The small script should run
  automatically, and ask you for a username and password.  If you do not
  type smith and justdoit, you wont be able to boot the computer. Later
  you will learn how to use a Unix, NT or Radius server to check valid
  user names.


  4.4.  Setting Up Linux

  In order to set up Linux, you will need to boot the floppy disk
  provided with the RedHat Linux distribution. BpBatch includes a
  command that can redirect the boot to the floppy: FloppyBoot.
  Unfortunately, it does not seem to work correctly with this special
  boot floppy (any suggestion is welcome to fix this). Consequently, you
  will probably need to boot a computer without bootprom for this first
  part of Linux setup.

  Set up RedHat Linux on your client, with network support, and any
  packages you may want. You may want to recompile the kernel to better
  fit your hardware, but it is not necessary.


  4.4.1.  Configuring the Client

  It is probably a good idea to include BOOTP support to the kernel, so
  that you do not have to customize the client IP address manually.

  In order to reduce network load, you might also want to setup the
  filecache for caching on the hard disk files that are loaded by NFS.
  Roughly, the principle of the filecache is that whenever a symbolic
  link from the cache subdirectory is followed, it is replaced by its
  target. If the target is itself a subdirectory, each entry of the
  subdirectory becomes a symbolic link to the original entry of the
  foreign filesystem.  The filecache has been written by Unifix GmbH,
  and is part of Unifix Linux 2.0. It is freely distributable, and you
  can get the necessary files from
  http://cuiwww.unige.ch/info/pc/remote-boot/soft/filecache.tar.gz.  In
  order to use the filecache, you have to

  ╖  apply a patch to the kernel (file patch-filecache), enable
     filecache support through make config or whatever you prefer, and
     recompile the kernel

  ╖  copy the filecache binary file to /sbin

  ╖  create a mount point called /mnt/nfs (using mkdir)

  ╖  copy filecache.conf to /etc. This file contains the following
     lines:

     Max 100 MB 50 % #
     Cache /mnt/nfs/usr /usr
     Cache /mnt/nfs/opt /opt



  ╖  copy the content of /usr and /opt to the server, export them read-
     only with anon=0 (for allowing root access) and mount them under
     /mnt/nfs (add a line for that in /etc/fstab)

  ╖  rename /usr as /usr.orig

  ╖  link /usr to /mnt/nfs/usr

  ╖  rename /opt as /opt.orig

  ╖  link /opt to /mnt/nfs/opt

  ╖  ensure that /usr and /opt are not empty and contains the correct
     directories

  ╖  recursively remove /usr.orig and /opt.orig

  ╖  copy filecache.init to /etc/rc.d/init.d

  ╖  And finally link /etc/rc.d/rc3.d/S35filecache to
     /etc/rc.d/init.d/filecache.init

     If you successfully followed each of these steps, you should have
     the filecache working next time you boot, as long as you do not
     forget to use your patched kernel.


  4.4.2.  Testing the Configuration

  Copy your compressed kernel image (zImage, bzImage, vmlinuz or
  whatever you call it) to the server /tftpboot directory as linux.krn.
  If you had to unplug the bootprom from the PC, you can now plug it
  again. When BpBatch starts, type LinuxBoot "linux.krn" "root=/dev/hda1
  BOOT_IMAGE=linux" (assuming that the root ext2 filesystem is on the
  first partition). Alternatively, if you did setup your configuration
  on a computer without bootprom, just boot let it boot using the loader
  you installed (lilo, ...). But in the later case, if you want the
  filecache to work, you should have explicitely installed your kernel
  with filecache support at the right place.

  Wait until the system comes up.  If you installed the filecache, you
  can check that /usr has exploded into a directory with some symlinks
  and some already-exploded directories. Now start the programs that the
  end-users will use most of the time, in order to load them once for
  all to the hard disk.


  You can still make adjustements to your configuration, like on any
  stand-alone linux station.


  4.4.3.  Building the Disk Image

  When you are happy with your configuration, login as root, go to the
  /tmp directory and run our mrzip program.  MrZip is a command
  interpreter like BpBatch, but it can understand more commands than
  BpBatch does. In particular, it can understand the following commands:


       ______________________________________________________________________
       showlog
       filter -"tmp/*"
       filter -"var/log/*"
       fullzip "/" "/tmp/linux.imz"
       ______________________________________________________________________




  This will create a disk image in /tmp/linux.imz. Move it to the server
  /tftpboot directory. Then copy the following batch file to /tftp¡
  boot/linux.bpb:


       ______________________________________________________________________
       hidelog
       setpartitions "linux-ext2:992 linux-swap:32"
       fullunzip "linux.imz" 1
       clean 2
       linuxboot "linux.krn" "root=/dev/hda1 BOOT_IMAGE=linux"
       ______________________________________________________________________




  The BOOT_IMAGE argument is to stay compatible with lilo for RedHat 5.1
  and later rc.sysinit.

  Your remote-boot linux configuration is ready ! You can now either set
  the BOOTP-option-155 to "linux", or type include "linux.bpb" from
  within BpBatch to test it.


  4.4.4.  System Maintenance and Upgrades

  If you want later to upgrade software, install bug fixes and security
  fixes, proceed as follow:

  ╖  Remote-boot a client computer to get a fresh linux install

  ╖  Make your changes

  ╖  Redo the disk image

  ╖  Copy the new image in place of the old one on the server

     That means, you can upgrade software on your server-based
     configuration as if it were a purely local install.





  4.5.  Setting up DOS 6 and Windows 3.1

  On the client computer, boot on your favorite dos floppy disk (either
  remove the bootprom or type FloppyBoot within BpBatch).  Format the
  dos partition of your hard-drive with the /S option, in order to put
  the operating system on it.  The size of the partition is not
  important, as disk archives created with MrZip Create a DOS
  subdirectory, copy DOS in it. Install your favorite network client
  (for instance Microsoft LanManager), Windows 3.1, and so on. If you
  use Microsoft LanManager, do not use DHCP for the IP configuration as
  it is a very poor implementation that will almost surely fail with
  reasonable network load. To do that, add the following lines in your
  protocol.ref file, in the section that loads tcptsr (of course,
  replaces the xxx by your true IP parameters):

          IPADDRESS0 = xxx xxx xxx xxx
          SUBNETMASK0 = 255 255 xxx xxx
          DEFAULTGATEWAY0 = xxx xxx xxx xxx
          DISABLEDHCP = 1



  Do not be afraid to use EMM386 to optimize the memory usage, and even
  to include the area where you put your network adapter ROM, since it
  is not used anymore at this time. But carefully exclude the network
  adapter RAM, or you will not be able to connect to your server. Use
  the NOEMS parameter.

  If you want to ensure that the client machine cannot be used without a
  valid login name, download our nobreak pseudo-device driver (available
  at http://cuiwww.unige.ch/info/pc/remote-boot/soft/nobreak.zip) and
  run it at the beginning of your config.sys. Then add something like
  this to your autoexec.bat:


       ______________________________________________________________________
       rem -- we use the dummy file c:\logged as a flag
       del c:\logged >nul
       :loginneeded
       cls
       echo Please type in your login name and password
       echo.
       net logon *
       rem -- the login script should have created c:\logged
       if not exist c:\logged goto loginneeded
       del c:\logged
       rem -- now enable break again
       echo Yes >NOBRK
       ______________________________________________________________________




  Ensure that your client boot well by rebooting the client and
  evaluating the following commands within BpBatch interactive mode:

          HideBootprom
          HdBoot




  4.5.1.  Building the Disk Image

  On the server, make a share called admin for instance, on which you
  will put some stuff for the system administrator.  If the server is a
  Unix machine, it is a good opportunity to put in admin a softlink to
  the /tftpboot subdirectory, so that you can put images in it directly
  from the client.  Within admin, create a /utils subdirectory and put
  the following files in it:

  ╖  mrbatch.exe, the DOS version of BpBatch

  ╖  mrzip.exe, the DOS version of the program for building disk images

  ╖  bpbatch.hlp, the on-line help file

     You might also like to put in the same directory a simple MrZip
     script named zipdos.mrz file that contains the commands needed for
     building a DOS image, like this one:


       ______________________________________________________________________
       showlog
       filter -"lanman.dos/lmuser.ini"
       filter -"temp/*"
       filter -"*.swp"
       fullzip "c:/" "L:/tftpboot/dos.imz"
       ______________________________________________________________________




  Now go back to your client, mount the admin volume on drive L:, go to
  your utils directory and type the following command:

          mrzip -b zipdos



  One minute later, you will have a new file in the server /tftpboot
  subdirectory called dos.imz, which is a compressed image of your hard
  disk. Copy the following batch file to /tftpboot/dos.bpb:


       ______________________________________________________________________
       hidelog
       setpartitions "bigdos:1024"
       setbootpart 1
       fullunzip "dos.imz" 1
       hidebootprom
       hdboot :1
       ______________________________________________________________________




  Your remote-boot DOS configuration is ready ! You can now either set
  the BOOTP-option-155 to "dos", or type include "dos.bpb" from within
  BpBatch to test it.


  4.5.2.  Adapting the configuration for other machines

  If you want to customize some settings according to the machine,
  typically the IP settings since Micro$oft DHCP is buggy, you can setup
  BpBatch to change some files before booting.  Firsti go to the
  lanman.dos directory and do

          copy *.ini *.ref


  Then edit the .ref files and replace all fixed parameters with BOOTP
  variable names as in the following examples:

          computername = ${BOOTP-Host-Name}
          ipaddress0 = ${MS-IPAddress}
          subnetmask0 = ${MS-IPSubnet}
          defaultgateway = ${MS-IPRouter}


  Then rebuild the disk image as previously.  Note that for IP parame¡
  ters, we do not use the BOOTP variables directly because LanManager
  needs then as space-separated numbers instead of dot-separated num¡
  bers. Change dos.bpb to the following:


       ______________________________________________________________________
       hidelog
       setpartitions "bigdos:1024"
       setbootpart 1
       fullunzip "dos.imz" 1
       set MS-IPAddress="$BOOTP-Your-IP"/.= /
       set MS-IPSubnet="$BOOTP-Subnet-Mask"/.= /
       set MS-IPRouter="$BOOTP-Routers"/.= /
       patch "{:1}lanman.dos/protocol.ref" "{:1}lanman.dos/protocol.ini"
       patch "{:1}lanman.dos/tcpputils.ref" "{:1}lanman.dos/tcputils.ini"
       patch "{:1}lanman.dos/lanman.ref" "{:1}lanman.dos/lanman.ini"
       hidebootprom
       hdboot :1
       ______________________________________________________________________




  If you prefer, you can also put the .ref files in the server /tftpboot
  directory instead of in the disk image.

  We like to be able to easily change the computers configuration
  without rebuilding the image. To do that, copy your autoexec.bat and
  config.sys as autoexec.ref and config.ref to the server /tftpboot and
  add the following two lines to the batch file above:

          patch "autoexec.ref" "{:1}autoexec.bat"
          patch "config.ref" "{:1}config.sys"


  You can then freely change the files and even customize them with
  machine-dependant values obtained from BOOTP.

  After making any change to the client machine configuration, do not
  forget to rebuild the disk image using mrzip if you want to preserve
  your changes.


  4.5.3.  System Maintenance and Upgrades

  If you want later to add new software or change anything else, proceed
  as follow:

  ╖  Remote-boot a client computer to get a fresh install

  ╖  Make your changes

  ╖  Redo the disk image

  ╖  Copy the new image in place of the old one on the server

     That means, you can upgrade software on your server-based
     configuration as if it were a purely local install.


  4.6.  Setting up Windows 95

  In previous versions of this document, we used the Microsoft server-
  based installation of Windows 95, but it was really too much pain and
  not much worth:

  ╖  It is very, very bogus

  ╖  Many software package do not support it and their install will
     fail.  Among them, Microsoft Internet Explorer, OnNet 32, Novell's
     Protected-mode client (which is MUCH more secure than Microsoft
     Client for Netware).

  ╖  It cannot be used with the Microsoft Network client over TCP/IP,
     since Microsoft provides no real-mode driver for TCP/IP compatibe
     with Windows 95. That means, it cannot be used with Samba

  ╖  It makes software upgrades almost impossible since every client
     turned on will lock many DLLs on the server, and thus produce
     sharing violations if you try to upgrade them.

     Consequently, we throwed away of this document all the informations
     and bug-workaround collected during months (you can still find them
     as a HTML document at http://cuiwww.unige.ch/info/pc/remote-
     boot/win95old/win95old.html) and turned to our new disk-based
     remote-boot concept.  Basically, the configuration for Windows 95
     is now almost as easy the configuration for DOS.


  4.6.1.  Setting up a Stand-Alone Client

  Setup a regular Windows 95 client, either starting from scratch as
  explained in the configuration of a DOS client, starting from the DOS
  client and installing over the network (that is what we did).  You can
  also start with a preconfigured Windows machine, but you will probably
  have less knowledge of what stuff is on the hard disk.

  Proceed as described above for a DOS client. It is usually NOT
  necessary to use EMM386 with Windows 95.  If you are using Windows 95
  OSR2 (alias MSWIN 4.1, alias Windows 95 service pack 1, alias Windows
  95 with Internet Explorer), you should add the following line in the
  [Options] section of MSDOS.SYS (yes, it is a text file):


       ______________________________________________________________________
       AUTOSCAN=0
       ______________________________________________________________________




  This will let Windows know that you do not want ScanDisk to be runned
  automatically at boot time.

  If you want to reduce network and server load (which will improve your
  system performances) while keeping all softwares on the server, you
  should consider installing the excellent Shared LAN Cache, from
  Measurement Techniques, Inc (see http://www.lancache.com).  This
  software runs on each client computer, and caches to the local hard
  disk every data obtained from the network. Even MS-Office starts much
  faster the second time you run it... You need one license per client
  computer, but it is not very expensive, and the firm make special
  prices for universities and colleges. The best thing to do is to go to
  their Web site and download the free evaluation copy.


  4.6.2.  Building the Disk Image

  Your MrZip script will be named zipwin95.mrz and contain:


       ______________________________________________________________________
       showlog
       filter -"temp/*"
       filter -"*.swp"
       fullzip "c:/" "L:/tftpboot/win95.imz"
       ______________________________________________________________________




  To build the image, mount the admin volume on drive L:, go to your
  utils directory and type the following command:

          mrzip -b zipwin95



  A few minutes later, you will have a new file if the server /tftpboot
  subdirectory called win95.imz, which is a compressed image of your
  hard disk. If your compressed image was bigger than 87 MB, it has
  probably been splitted in two or more fragments.  These fragments will
  automatically loaded one after the other when needed. Note that an
  image bigger than 87 MB will usually take More than one minute to
  uncompress and may irritate your users.  Our Windows 95 image is only
  70 MB big, because most software (except Office and Explorer)
  completely reside on the server. Only 45 seconds are needed to
  uncompress the image and restore the full disk.

  Copy the following batch file to /tftpboot/win95.bpb:


       ______________________________________________________________________
       hidelog
       setpartitions "bigdos:1024"
       setbootpart 1
       fullunzip "win95.imz" 1
       hidebootprom
       hdboot :1
       ______________________________________________________________________




  Your remote-boot Windows 95 configuration is ready ! You can now
  either set the BOOTP-option-155 to "win95", or type include
  "win95.bpb" from within BpBatch to test it.


  4.6.3.  Adapting the configuration for other Machines

  The big difference between Windows 3.1 and Windows 95 is that the
  later includes code for Plug-and-play , ie. automatic detection of
  your hardware. This not a bad thing in itself, but the trouble is that
  it is often too sensible, and that it sometimes fails.

  If you try to start another client with exactly the same boot image,
  you will probably get several messages during startup telling that
  Windows has detected new hardware: a new sound card, a new hard-disk,
  a new network card, and even a new mouse... There can be two reasons
  for that:

  ╖  the devices may not use the same ressources (for instance the mouse
     is not connected on the same port, or the sound card is not
     connected in the same slot - yes, that is detected)

  ╖  the devices may tell to Windows 95 their personal serial number
     (for instance, every Windows 95 differenciate every network card on
     the basis of its world-wide unique ethernet address)

     The fact that Windows 95 discover that the hardware has changed may
     not be a problem if the plug-and-play works as-is, but it become a
     problem when the plug-and-play does not work. For instance, Windows
     95 plug-and-play for our Logitech PS2/aux mouse does not work, and
     result in no mouse at all. To solve such kind of problems, arrange
     to have all computers as similar as possible, or make different
     images for different hardware. Later, you will discover that you
     can simply use the same image and just have several copies of the
     registery, that you can copy after having restoring the disk image
     but before booting.

  The thing you cannot avoid to differ between computers is the network
  card. PCI cards usually do not mind, but ISA Plug and Play do.  Bad
  luck for us, the plug-and-play code for our SMC EtherEZ card hangs the
  computer. The only solution is to let Windows 95 believe that it
  already know the network card, and that it is not necessary to trigger
  plug-and-play. The trick for doing that is to automatically insert an
  entry for the network card in Windows 95 registery, before starting
  it.  Note that this trick is not any more needed with most PCI cards.

  Move the autoexec.bat to the server as described above for DOS.  Edit
  it (on the server) and add the following lines:

  rem --- Patch Windows registery in order to avoid plug-and-play detection
  regedit /L:c:\windows\system.dat /R:c:\windows\user.dat c:\temp\patch.reg


  regedit is a standard Windows 95 program that let you browse the reg¡
  istery if you start it from within Windows 95, or do simple operations
  on the registery if you call it from DOS.  Run regedit under Windows
  95, search for your network card, usually under

          HKEY_LOCAL_MACHINE\Enum\ISAPNP


  and export the branch using the File menu. This will create a text
  file, that you should same as patch.ref in the server /tftpboot dire¡
  tory. Edit this file and find out where the card ethernet address is
  stored (do that on two different machines and compare the files if you
  can't find it by yourself). Replace it by a pettern in the form
  ${MACID}.  Then add lines to the win95.bpb script like this:

          set macid = "$BOOTP-Client-ID"
          patch "patch.ref" "{:1}temp/patch.reg"


  (do any necessary string manipulation for setting MACID if it is not
  exactly the client Ethernet address).  That's all, your clients should
  not any more try to autodect the network card.

  Once again, this whole trick is not necessary when using PCI network
  adapters.  Incidentally, we can use the same mechanism for
  automatically configuring the hostname, which Windows 95 does not seem
  to take into account when configuring through DHCP. We just add the
  following line to our patch.ref file:


       ______________________________________________________________________
       [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\VNETSUP]
       "ComputerName"="${BOOTP-Host-Name}"

       [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP]
       "HostName"="${BOOTP-Host-Name}"

       [HKEY_LOCAL_MACHINE\System\CurrentControlSet\control\ComputerName\ComputerName]
       "ComputerName"="${BOOTP-Host-Name}"
       ______________________________________________________________________




  Using this small registery trick, your configuration should normally
  be portable for all machines with similar configurations. If you
  cannot avoid that Windows detect some hardware as new on one machine,
  try to rebuild the disk image from this machine. This will include the
  registery configuration specific to this machine into the image, and
  hopefully supress the problem.


  4.6.4.  System Maintenance and Upgrades

  If you want later to upgrade software, install bug fixes and security
  fixes, proceed as follow:

  ╖  Remote-boot a client computer to get a fresh install

  ╖  Make your changes

  ╖  Redo the disk image

  ╖  Copy the new image in place of the old one on the server

     That means, you can upgrade software on your server-based
     configuration as if it were a purely local install.


  4.7.  Setting up Windows NT

  We do not use Windows NT for remote-boot client computers but we have
  tested our system to ensure that it work as well. And it works.

  As our utilities currently have no support for NTFS (we neither have
  the documentation nor the time to do that, but I would be happy to
  help anyone who is interested in doing it), you will have to install
  NT on FAT16 (simply do not convert your partitions to NTFS during the
  setup).

  Copy your win95.bpb boot script to winnt.bpb.  Change the
  setpartitions line in winnt.bpb to the following:

          setpartitions "BIGDOS:512 BIGDOS:512"


  Then boot Windows 95 using this script, and install your NT client on
  drive C. Do not worry about the second partition for now.  Do not
  install too much stuff, or you will get a really large and slow-to-
  uncompress image.  Remove Windows 95 from the disk disk C, you do not
  need it in a Windows NT image (the boot menu is handled by the boot¡
  prom, not by NT boot loader).

  Reboot your computer in without overwriting the hard disk, ie. do not
  execute the winnt script but just

          hidebootprom
          hdboot


  Your NT station should start-up correctly. Make any necessary cus¡
  tomization.


  4.7.1.  Building the Disk Image

  The trouble with Windows NT is that direct disk access is prohibed by
  the kernel. That means, MrZip will not even be able to read the boot
  sectors. The best way to do an image is then to boot Windows 95 and to
  run MrZip from a DOS window. To do that, change the winnt.bpb script
  so that the Windows 95 image is not restored on the first but on the
  second partition:


       ______________________________________________________________________
       hidelog
       setpartitions "BIGDOS:512 BIGDOS:512"
       setbootpart 2
       fullunzip "win95.imz" 2
       hidebootprom
       hdboot :2
       ______________________________________________________________________




  (if you have any supplementary patch, change the "{:1}" to "{:2}").
  Boot with this script; you should have Windows 95 running, but a new
  drive D: should be available, with Windows NT inside.

  Make your disk image as usual (but on D:, of course), and save it as
  winnt.imz on the server /tftpboot directory.  Edit one last time the
  winnt.bpb script like this:


       ______________________________________________________________________
       hidelog
       setpartitions "BIGDOS:512 BIGDOS:512"
       setbootpart 1
       fullunzip "winnt.imz" 1
       clean 2
       #fullunzip "win95.imz" 2
       hidebootprom
       hdboot :1
       ______________________________________________________________________




  Your Windows NT remote-boot configuration is ready. Of course, if you
  do not like to have two partitions, you can setup a single partition
  instead. But when you have to rebuild the image, you will have to
  setup the second partition again for booting Windows 95.


  4.7.2.  System Maintenance and Upgrades

  If you want later to upgrade software, install bug fixes and security
  fixes, proceed as follow:
  ╖  Remote-boot a client computer to get a fresh install

  ╖  Make your changes

  ╖  Edit winnt.bpb: comment the clean and winnt fullunzip, uncomment
     win95 fullunzip

  ╖  Redo the disk image

  ╖  Copy the new image in place of the old one on the server

     That's all, folks !


  4.8.  Troubleshooting

  This section lists most frequently encountered problems.

     The image download never ends
        You are probably using a standard TFTP server, and it cannot
        handle more than 65535 packets of 512 bytes (or even 32767
        packets for the Solaris server). That is, your image must be
        fragmented in pieces of no more than 30 MB (or 15 MB for
        Solaris). See under CopyArchive for instructions on fragmenting
        an existing image. But you should seriously thing about using
        InCom's extended TFTP server, as it is much more efficient (it
        uses packets of 1408 bytes instead of 512 bytes).

     The archive decompression fails immediately
        There are two possibilities. Either the image is really
        corrupted on the server (try use MrZip to see if it is the
        case), or the file transfer has failed because of TFTP timeout.
        TFTP timeout occurs when the network is too heavily loaded (for
        instance if you try to download a huge image with more than four
        clients at a time). In this case, BpBatch does not retry
        indefinitely because it would not help. Shut down a few
        computers and retry with no more than four computers (or maybe
        even three).  If you often need to download images for a lot of
        computers, you can try our special Broadcast TFTP server (see
        the section dedicated to it).

     The computer hangs instead of downloading/unzipping
        May be your computer has a bad VESA support. Try giving the -v
        command-line argument or setting the VESA variable to "OFF".

     VESA scrolling is broken
        We use a VESA 1.1 function for scrolling. If your video adapter
        does not support VESA 1.1, forget it. If the scrolling works for
        one page, but then produces a strange strippled pattern, do not
        worry. This is a known bug, I will fix it as soon as I have time
        for it (VESA scrolling is not really essential...)

     There is a corrupted file in the cache
        When a file in the cache is corrupted by an external program, it
        is automatically removed from the cache. When a file in the
        cache is not fully written (because the computer is turned off
        during the file transfer), it is also automatically removed. But
        if the server transmits a corrupted file or if the transfer
        aborts from the server side, it is possible that this file stays
        in the cache. You can clean-up the cache simply by holding both
        shift down while BpBatch access it for the first time.
        Alternatively, you can evaluate clean -1 in interactive mode.

     The EXIT command does not work in a batch file
        This is not a bug. Exit is not a command.  There is no exit or
        quit command because it does not make any sense to exit from a
        boot script without booting. And MrBatch is really the same
        program as BpBatch.  What you can do instead is calling HdBoot.
        This makes sense, and the DOS version will cleanly exit instead
        of rebooting.  Note that you can exit from the DOS version at
        any time by pressing Ctrl-Break. This will restore all hooked
        interrupts before leaving.

     The Print command does not print
        If you try to print something and immediately enter interactive
        mode, you may not see your text. This is because your text was
        written on the runtime screen and the Interact command has
        switched the display to the Log screen. Just put a GetKey after
        the print commands and you will see the text output.

     MrZip says Malloc failed
        MrZip needs a lot of conventional memory to run.  If you
        encounter this problem, first ensure that you have unloaded the
        bootprom either using HideBootprom or using InCom's bputil.  If
        you run MrZip from bare MS-DOS (not within Windows 95 DOS box),
        you should use EMM386 to load the network drivers high in order
        to get as much conventional memory as possible. From a Windows
        95 DOS box, there is usually no problem (as long as you have not
        left your old 16-bit stuff in your autoexec.bat when you
        installed Windows 95).

     MrZip aborts while reading directories
        This bug has already been fixed once. Get the latest release of
        MrZip. If the problem persists, try to build your image with
        Trace set to "ON" (and usually PauseLog set to "OFF"); this will
        let you discover which file causes the problem. Send a detailled
        bug report.

     MrZip cannot access some file
        MrZip is probably trying to read a locked, open or special file,
        such as Windows swap file. Such files should usually not be
        included in the image and should be filtered out (using the
        filter command).  It is also possible that the operating system
        is playing you a trick.  If MrZip does not tell you what file
        causes the problem, try to build your image with Trace set to
        "ON" (and usually PauseLog set to "OFF").  You can also try to
        use direct disk access (that is, do not refer the source
        partition as "C:" or "/" but as "{:1}" or whatever partition it
        is). Using direct disk access is usually slower because we have
        less buffers than the operating system, but it may be sometimes
        more reliable.

     Disk images are always reloaded from the server
        Disk images are stored in the special cache area and should not
        be reloaded if they have not changed on the server. However, as
        the cache area always starts after the last used partition,
        changing the total size of partitions will move the location of
        the cache and thus destroy its content. Another possible reason
        for a file disappearing from the cache is that the previous file
        has grown more than one-and-an-half times its initial size. The
        file would then have been overwritten and need to be downloaded
        once again. This should almost never occurs.  A third possible
        reason is a too small cache area. If the free space left outside
        the partitions is less than one-and-an-half times the sum of all
        compressed image sizes, only the most recently used images will
        be present in the cache and the other will have to be reloaded
        on demand.

     Red Hat Linux 5.1 does not boot properly
        This distribution assumes Linux was booted using lilo and checks
        for the BOOT_IMAGE command line argument (in
        /etc/rc.d/rc.sysinit). Simply add it in the linuxboot call, or
        change your rc.sysinit.

     The broadcast TFTP ramdisk hangs (Got in bound state)
        Linux dhcp client is a program that dynamically changes the IP
        address of the client according to DHCP offers. If the address
        is offered forever (infinite lease time), the DHCP client just
        set the address and returns (this is what we expect).  However,
        if the lease time is limited, the DHCP client must remain loaded
        and ask for new addresses every few minutes. And if the DHCP
        client does not return, MrBatch will never be loaded...  The
        solution is to give an infinite lease time (sometimes encoded as
        -1).

     File access hangs under BpBatch, but not under MrBatch
        This problem occured on an AMI BIOS dated 94/07/25. We
        investigated a little bit, and found no solution. It seems that
        this problem is due to a bug in this BIOS (some register or
        memory location must be destroyed).

     Unzip of a fragmented archive fails (Malloc failed)
        This problem was introduced with PXE compatibility, but has now
        been fixed. Please get the latest version.

     MrBatch and MrZip complain about the terminal under RedHat 5.x
        This problem is due to libc6, which is not fully downward
        compatible with libc5. Linux version was linked with libc5. With
        the growing number of complaints, we decided to move the
        distribution to libc6.  If you encounter this problem, simply
        get the latest version.

     MrBatch and MrZip do not start under Linux (file not found)
        This problem is the reverse of the previous one. Now that the
        distribution is libc6 ready, it cannot be used any more with
        libc5. If you encounter this problem, simply upgrade your Linux
        box (Well, if we hear too much complaints, we might try to keep
        two distributions...).


  5.  Remote-Boot Tools Reference Manual

  This section provides detailled informations on the use of the tools
  we developped at the CUI, University of Geneva for this remote-boot
  configuration.


  5.1.  BpBatch, MrBatch and MrZip

  These three names stand for three variants of the same program, with
  the following characteristics:

  ╖  BpBatch is a special program that can be started from the BootProm
     before the operating system is loaded. It is made of two parts:
     bpbatch.P, the dynamic loader, and bpbatch.ovl, the program itself.
     BpBatch has full disk I/O capabilities through our own
     implementation of FAT16, FAT32 and Ext2fs, as well as remote
     network I/O capabilities through the BootProm TFTP API.  BpBatch
     was compiled under DOS using Borland C 5.0 and Turbo Assembler 3.2.

  ╖  MrBatch is the DOS/Linux version of BpBatch.  All commands
     recognized by BpBatch are recognized by MrBatch and vice versa.
     This is very usefull if you want to test your batch scripts from a
     DOS/Linux session.  Under DOS, MrBatch emulates remote I/O by OS-
     based file access if the bootprom is not available. Under Linux,
     the bootprom cannot be seen anymore but MrBatch can emulate it
     using Linux IP support, or use OS-based file access.  MrBatch was
     compiled under Linux using GCC 2.7.2.1 and under DOS using Borland
     C 5.0 and Turbo Assembler 3.2.

  ╖  MrZip is an interpreter that recognizes a superset of MrBatch
     language, and that serves to build disk images.  In MrZip, the
     limited remote file I/O is replaced by a full-featured OS-based
     file access. MrZip does not include VESA support.  MrZip was
     compiled under Linux using GCC 2.7.2.1 and under DOS using Borland
     C 5.0 and Turbo Assembler 3.2.


  5.1.1.  Command Line Arguments

  All programs accept the same syntax of arguments. MrBatch and MrZip
  take them from the command line, while BpBatch look for them in the
  BOOTP option 155 (decimal). Here is the syntax of the arguments:

          [-x] [-l] [-b] [-v] [-w] [-i] [script-basename]


  where:

  ╖  -x disable the use of extended memory

  ╖  -l disable the use of ISO-latin-8859-1 as default character set

  ╖  -b cancel the bootprom detection (which cause a floppy seek under
     DOS)

  ╖  -v cancel the VESA detection (which cause a switch to full screen
     under Windows 95)

  ╖  -w enable direct disk write access (disabled by default under DOS
     and Linux)

  ╖  -i enable interactive mode even if a script name is provided

     The script-basename is optional. If provided, MrBatch and BpBatch
     load the file with the .bpb extension, and MrZip loads the file
     with the .mrz extension. If not provided, MrBatch and MrZip run in
     interactive mode while BpBatch loads the file with the same
     basename as the BOOTP Boot file and a .bpb extension.


  5.1.2.  Syntax rules

  The following rules apply when BpBatch parses an input line.

  ╖  Commands are parsed line by line. Lines are separated by CR and/or
     LF.

  ╖  The maximal line length is currently 255 characters.

  ╖  Keywords and variable names are case-insensitive.

  ╖  " is interpreted as the special string delimiter

  ╖  When ${variable} or $variable is encountred, it is substituted by
     the value of the variable, or by an empty string if the variable is
     undefined.  The substitution also occurs within a string. Moreover,
     the resulting substituted value must be explicitely enclosed
     between double quotes if used as a string value (ie. one should
     merely speak of macro expansion than of a variables).

  ╖


  ╖  \a is substituted by the audible-bell character (ASCII 7)

  ╖  \b is substituted by the backspace character (ASCII 8)

  ╖  \n is substituted by the newline character (ASCII 10)

  ╖  \r is substituted by the return character (ASCII 13)

  ╖  \t is substituted by the tabulation character (ASCII 9)

  ╖  \v is substituted by the vertical-tab character (ASCII ...)

  ╖  \nnn where n is a 3-digit octal number between 000 and 377 is
     substituted by the character with ascii code specified

  ╖  \X where X is any other character not listed above is substituted
     by X itself. In particular,

  ╖  \" is substituted by a regular double-quote (not a string-
     delimiter)

  ╖  \$ is substituted by a regular dollar sign (not variable
     substitution)

  ╖  \\ is substituted by a regular backslash (not a special character)

  ╖  The character "end of string" (ASCII code 0) CANNOT be used
     anywhere as it is used internally as end-of-string delimiter

  ╖  The character "floating diaeresis" (ASCII code dec 249, hex F9,
     octal 371) CANNOT be used in any string as it is used internally as
     string delimiter in the input parsing routine.

  ╖  The character "block space" (ASCII code dec 255, hex FF, octal 377)
     CANNOT be used in any variable value as it is used internally as
     variable delimiter.

  Empty lines are ignored.  Lines starting with a sharp (#) are treated
  as comments and are not interpreted.  Lines starting with a column (:)
  are treated as labels and are not interpreted.


     String expressions
        Strings are delimited by opening and closing double-quotes:

                "Hello world"


     To include double-quotes within a string, quote them using a back¡
     slash:

             "I said: \"Hello world\""


     Strings can be postfixed with a few operators.

     ╖  The character substitution operator:

                "Hello world"/o=u/      ==      "Hellu wurld"
                "198.76.54.32"/.= /     ==      "198 76 54 32"



     ╖  The word selection operator (zero-based):


                "Hello world"{0}        ==      "Hello"
                "198 76 54 32"{1-3}     ==      "76 54 32"



     ╖  The substring selection operator (zero-based):

                "Hello world"[4]        ==      "o"
                "Hello world"[4-7]      ==      "o wo"



     Operators can be chained by postfixing one after the other.  For
     informations about the string length and word count operators, see
     under "Numerical expressions".


     Numerical expressions
        Numerical expressions work on 32-bits integer numbers (from
        -2,147,483,646 to 2,147,483,647). Hexadecimal octal and binary
        numbers are not understood.  Whenever a numerical expression is
        expected, the following are recognized:

     ╖  A positive or negative integer number

     ╖  An expression in the form (expr1 op expr2) where op can be
        either +, -, * (multiply), / (divide) or % (modulo) and expr is
        a numerical expression.  Note that EACH operation MUST be
        enclosed between parenthesis :

                ((3 * 5)+2)             == 17



     ╖  The string-length operator (@), followed by a string :

                @"Hello world"          == 11



     ╖  The word-count operator (#) followed by a string :

                #"Hello world"          == 2




     Durations
        A few commands expect durations as arguments. Durations are
        measured in seconds, with a precision of up to a tenth of
        second:

                Delay 3                 waits for 3 seconds
                Delay 0.3               waits for 3/10 seconds




     Colors
        Whenever a color is expected, you can either use the numeric
        value of the color or its symbolic name (case-insensitive).  The
        following colors are recognized




                Black           0
                Blue            1
                Green           2
                Cyan            3
                Red             4
                Magenta         5
                Brown           6
                LightGray       7
                DarkGray        8
                LightBlue       9
                LightGreen     10
                LightCyan      11
                LightRed       12
                LightMagenta   13
                Yellow         14
                White          15




     File References
        File names are strings. They must therefore always be enclosed
        between double-quotes. File names are case-sensitive on case-
        sensitive filesystems, case-insensitive on case-insensitive
        filesystems.  Slash and backslash can be freely used one in
        place of the other.  Do not forget to double backslash since a
        single backslash is an escape character.

        There are two kinds of file references:

     ╖  Direct disk files

     ╖  Foreign files

        Direct disk files are referenced using the following notation:

                "{disk:partition}/absolute/filename"


     The disk number can be omitted and defaults to zero.  For instance,
     "{:1}/usr/bin" points to /usr/bin assuming there is such a direc¡
     tory on the first partition. Direct file I/O is solely based on our
     own file access routines (we do not use the operating system).

     There are two special partitions. Partition zero corresponds to the
     hard disk master boot record (MBR) and has a pseudo file-system
     which let you access the boot code. Partition minus-one (-1)
     corresponds to the cache filesystem (see below).

     Under BpBatch/MrBatch, foreign files correspond to remote files on
     the TFTP server when the BootProm is available:

             "help.bpb"           is the file help.bpb in the /tftpboot directory
             "gifs/MyImage.gif"   is a file in /tftpboot/gifs


     Other TFTP servers can be referenced :

             "198.76.54.32:help.bpb"


     If the other server is behind a gateway :

             "198.70.0.1/198.76.54.31:help.bpb"


     One can also specify a specific port for the TFTP connection :

             "198.76.54.32@89:getpasswd/smith"


     There can be only one open remote file at a time.  If the BootProm
     is not available, remote files are emulated using the operating
     system file I/O, but the same restriction apply.

     Under MrZip, foreign files correspond to files as seen by the
     operating system. There is no limitation, and foreign files can be
     used wherever direct disk files can be. Foreign files are usually
     faster than direct disk files, because the operating system has
     more buffers. Foreign files can refer to network files if supported
     by the operating system.

             "C:\\autoexec.bat"
             "C:/config.sys"
             "/mnt/net/usr"




  5.1.3.  The Cache Filesystem

  In order to reduce network load and to fasten the boot process, disk
  archives, linux kernels and possibly other files are cached on the
  hard disk. This disk cache is located at the end of the hard disk,
  between the last cylinder allocated in the partition table and the
  last physical cylinder of the disk (out of any allocated partition).
  There MUST be room between the last partition and the end of the disk
  if you want the cache filesystem to work.  The cache filesystem MUST
  work if you want to restore a disk image.

  The disk cache is organised in a volatile, CRC-validated filesystem :
  Each directory entry and each 32 KB data block is validated by a
  32-bits CRC. Whenever a directory entry or a data block unexpectedly
  changes, the file is automatically removed from the cache and
  downloaded again upon the next request.

  You can freely access the cache filesystem from within BpBatch,
  MrBatch and MrZip using direct disk access on the special partition
  "{:-1}".  To see the content of the cache, just type :

          logdir "{:-1}"


  If the cache ever gets corrupted and is not automatically cleaned
  (which should never occurs), you can either type :

          clean -1


  (in interactive mode) or hold both shifts down when BpBatch access the
  cache for the first time.


  5.1.4.  Special variables

  Some variable are initially set and/or have special meanings.  Some of
  them exist within all programs, other are only available under MrZip
  and other are only available when a BOOTP/DHCP reply has been
  received.



     General variables

     ╖  $Program is set to "BpBatch" within BpBatch, "MrBatch" within
        MrBatch and "MrZip" within MrZip

     ╖  $Basename is set to the basename of the script on which the
        batch interpreter was started

     ╖  $HelpFile is the name of the file loaded when Help is invoked.
        Default: "${Basename}.hlp"

     ╖  $BOOTP-... are variables set from the BOOTP/DHCP reply (see the
        paragraph on BOOTP/DHCP variables for more details)

     ╖  $DHCP-... are variables set from the DHCP reply (see the
        paragraph on BOOTP/DHCP variables for more details)

     ╖  $Disks is set to the space-separated list of sizes for each
        disk.  That means, #"$Disks" represent the number of disks and
        "$Disks"{0} is the size of the first disk

     ╖  $Keypressed is set to the next ready-to-read key available in
        the keyboard buffer (if available)

     ╖  $LBA    controls the use of LBA to access disks > 2Gb.  Default:
        "ON"

     ╖  $FDA    controls the use of fast disk access (write accross
        cylinders).  Default: "ON"

     ╖  $VESA   controls the use of VESA graphics.  Default: "ON" if
        available

     ╖  $Trace controls the display of each command before execution. It
        also controls the display of file names when creating new
        archives.  Default: "OFF"

     ╖  $AutoShowLog controls the automatic switch to the text log
        whenever the ESC key is pressed.  Default: "ON"

     ╖  $PauseLog controls the pause between each page of log when the
        log is visible.  Default: "ON"

     ╖  $CacheDisk is set to the disk used for caching remote files.
        Default: empty == 0, the first hard disk

     ╖  $CacheAlways controls the automatic caching of remote files
        copied, patched or drawn as GIF.  Default: "OFF"

     ╖  $CacheNever prevents any file from being cached.  Turn this
        variable on for diskless Linux boot.  Default: "OFF"

     ╖  $CacheReserve controls the preventive allocation of 25 percent
        more space than necessary in the cache partition, to let the
        files grow. Turn this variable off if you are short of disk
        space.  Default: "ON"

     ╖  $ExtMemory controls the use of Extended Memory (or XMS).  Once
        deactivated, extended memory cannot be reactivated.  Default:
        "ON" if available

     ╖  $IsoLatin controls the interpretation of upper ASCII codes in
        included and patched files. The IsoLatin settings are processed
        at the time the file is loaded, not at the time the file is
        processed.  Default: "ON"

     ╖  $ProgressX and $ProgressY controls the position of the progress
        window displayed in VESA graphics during archive download and
        decompression.  Default: 200 200

     ╖  $EXT2-Backup controls the update of superblock backups in Linux
        ext2 filesystem. Superblock backups take a few seconds to do and
        are never used by current kernels (only by e2fsck).

     ╖  $Security-Gateway controls the gateway-server used for user
        authentication. Our special authentication gateway must be
        running on the target computer.  Default: "${BOOTP-Server-
        IP}@89" (ie. the TFTP server, on port 89)

     ╖  $Security-Check contains the answer of the security server for
        the last check performed, either PASSED or FAILED.  Default:
        "FAILED"

     ╖  $Security-Passwd, $HelpTopic, $OnExit, $OnKey-...  are used
        internally.

        See also BOOTP variables and MrZip-specific variables.


     MrZip-specific variables
        The following variables are only used within MrZip.

     ╖  $TempPath controls the directory where temporary files will be
        stored.  Default: <empty> == current directory

     ╖  $DumpFormat controls the way archives are dumped to the log when
        requested.  It is a string containing

     ╖  "h"/"H" to display the archive header

     ╖  "b"/"B" to summarize/dump boot sectors

     ╖  "s"/"S" to display a short/long allocation summary

     ╖  "d"/"D" to display a short/long directory listing

     ╖  "f"/"F" to summarize/dump files

        Default: "hbD"

     ╖  $FragmentSize controls the size of archive pieces.  If you do
        not use InCom's extended TFTP server, you should set this to "30
        MB".  Default: "87 MB"

     ╖  $SourceArchive, $DestArchive, $Filter... are used internally.


     BOOTP variables
        The following BOOTP-... and DHCP-... variables are recognized,
        as long as a BOOTP/DHCP reply has been received (TCP/IP Bootprom
        must be reported as detected):











                $BOOTP-Client-ID
                $BOOTP-Your-IP
                $BOOTP-Server-IP
                $BOOTP-Gateway-IP
                $BOOTP-Bootfile
                $BOOTP-Server-Name
                $BOOTP-Subnet-Mask
                $BOOTP-Time-Offset
                $BOOTP-Routers
                $BOOTP-Time-Servers
                $BOOTP-Name-Servers
                $BOOTP-Domain-name-Servers
                $BOOTP-BOOTP-Log-Servers
                $BOOTP-Cookie-Servers
                $BOOTP-Lpr-Servers
                $BOOTP-Impress-Servers
                $BOOTP-Resource-Location-Servers
                $BOOTP-Host-Name
                $BOOTP-Boot-Size
                $BOOTP-Merit-Dump
                $BOOTP-Domain-Name
                $BOOTP-Swap-Servers
                $BOOTP-Root-Path
                $BOOTP-Extensions-Path
                $BOOTP-IP-Forwarding
                $BOOTP-Interface-MTU
                $BOOTP-All-Subnets-Are-Local
                $BOOTP-Broadcast-Address
                $BOOTP-NIS-Domain
                $BOOTP-NIS-Servers
                $BOOTP-NTP-Servers
                $BOOTP-Font-Servers
                $BOOTP-X-Display-Manager
                $DHCP-IP-Address-Lease-Time
                $DHCP-Message-Type
                $DHCP-Server-Identifier
                $DHCP-Message
                $DHCP-Renewal-Time
                $DHCP-Rebinding-Time
                $BOOTP-NIS+-Domain
                $BOOTP-NIS+-Servers
                $BOOTP-Server-Name
                $BOOTP-Bootfile
                $BOOTP-Mobile-IP-Agent
                $BOOTP-SMTP-Servers
                $BOOTP-POP3-Servers
                $BOOTP-NNTP-Servers
                $BOOTP-WWW-Servers
                $BOOTP-Finger-Servers
                $BOOTP-IRC-Servers
                $BOOTP-StreetTalk-Servers
                $BOOTP-STDA-Servers



     Other BOOTP/DHCP parameters can be used under the name

             $BOOTP-Option-n


     where n is the decimal representation of the BOOTP option number.

     Do not mix-up BOOTP-Gateway-IP, which is the gateway to use for
     TFTP and should be 0.0.0.0 if the TFTP server is in the same
     subnet, and BOOTP-Routers, which contains the default IP
     gateway(s). The TCP/IP Bootprom sometimes seems to set the value of
     BOOTP-Gateway-IP from the value in BOOTP-Routers, causing each TFTP
     ack packet to be sent to the router first. To avoid such behaviour,
     if your TFTP server is in the same subnet as the client, force
     BOOTP-Gateway-IP to 0.0.0.0 (thanks to Maciek Uhlig for having
     pointed out this problem).


  5.1.5.  Monitoring commands

  This section lists commands for monitoring the system state.  Optional
  arguments are listed between parenthesis (I would have prefered square
  brackets, but LaTeX do not like them at this place...)

     Interact
        Show the log and turn to interactive mode until QUIT or EXIT is
        entered.  Type HideLog before quitting if you want to avoid
        disturbing log messages during batch execution.


     Help (topic)
        Load the on-line help file (bpbatch.hlp) and display the
        description of the given topic. If no topic is provided, or if
        the topic is unknown, display the help index.


     Log
        Display the string on the log. No return/linefeed is implicitely
        added.


     Echo
        Display the string on the log and go to the next line.
        Equivalent to

                Log "text\r\n".




     LogVars (
        Log (ie. display on the log) all variables matching the given
        pattern.  The pattern can contain wildcards (? and *).

        Example: LogVars "BOOTP-*"              list all BootP variables



     LogDir
        Log (ie. display on the log) all files from the given path that
        match the pattern. The pattern can contain wildcards (? and *).

        Example: LogDir "/usr/g*p"              list files names like g...p



     LogTree
        Log the directory tree starting with the given path as root.


     LogFile
        Log the content of the file. The file must be no more than 64 KB
        big.


     ShowLog
        Make the log visible if it was hidden.  Automatically performed
        when ESC is pressed with "$AutoShowLog" == "ON" and when
        entering interactive mode.


     HideLog
        Prevent log messages to appear on the screen. Default state when
        BpBatch, MrBatch and MrZip are started on a script file.


     CaptureLog
        Record all log output to a 64 KB buffer until EndCapture is
        issued.  Wrap around buffer if the log output is more than 64 KB
        big.  This command can be used to create a text file with an
        arbitrary content.  The EndCapture MUST occurs within the same
        batch file.


     EndCapture (
        End up the capture of the log. If a filename is given, store the
        captured text to a file. Otherwise, discard it.


  5.1.6.  Control commands

  This section lists commands that control the batch execution.
  Optional arguments are listed between parenthesis.

     Include
        Load the given file and start up the parser on it. Go back to
        the current point when the include file processing is done.  The
        interpretation of characters above ASCII 127 within the include
        file depends on the value of $IsoLatin at the time the file is
        included.


     OnExit command
        Setup an exit-handler that will automatically be evaluated at
        the end of current batch file.


     Goto label
        Move the execution cursor to the given label (ie. the line
        starting with :label)


     Eval
        Perform all substitutions on the "command" and run the parser on
        it.


     If ...

          If (not) <expr1> (==|!=|<|>|>=|<=|=>|=<|<>) <expr2> <command>
          If (not) (ci) "str1" (==|!=|<|>|>=|<=|=>|=<|<>) "str2" <command>
          If (not) (ci) "str1" Match-Expr "pattern" <command>
          If (not) (ci) "str1" Match-Passwd "unix-passwd" <command>
          If (not) (ci) "str1" In "wordlist" <command>
          If (not) (ci) "str1" In-File "filename" <command>
          If (not) exist "filename" <command>



     These commands execute command; if the test succeeds.  The 1st form
     compares two numerical expressions.  The 2nd form compares two
     strings, optionally case-insensitive.  The 3rd form tests if "str1"
     matches the given pattern (wildcards allowed).  The 4th form tests
     if the clear password "str1" matches the Unix-crypted password.
     The 5th form tests if "str1" is included in the word list.  The 6th
     form tests if "str1" is included in the word file.  The 7th form
     tests if the given file exists.


     Set ...

          Set variable = "string-value"
          Set variable = <expr>



     Setup a value for the given variable. If the given value is a
     numerical expresison, it will be implicitely converted to a string.
     A variable can be used anywhere by refering it as $variable or
     ${variable}.  If the resulting reference is to be interpreted as a
     string, it should be enclosed between double quotes: "$variable" or
     "${variable}".


     Delay duration
        Waits until the specified duration (expressed in seconds)
        expired.  See also the paragraph on the format of durations.


     GetTime variable, GetDate variable
        Get the CMOS time and store it into variablein the form
        HH:MM:SS.  Get the CMOS date and store it into variablein the
        form YY/MM/DD.  This can be used to customize the behavior of
        your boot scripts depending on the time of day or on the date.


     SetTime
        Set the computer CMOS time or date to the given value.  If you
        have a security gateway (our special TFTP server) running, you
        can automatically adjust the CMOS time and date of the client
        computers at each boot by evaluating the following command:

                include "$Security-Gateway:gettime"


     If you want to understand what this command does, just type:

             logfile "$Security-Gateway:gettime"




     Poweroff
        Turn off the computer.  This command only works if the computer
        is Advanced Power Management (APM) compatible.


  5.1.7.  Keyboard-related commands

  This section lists commands that let you monitor the keyboard input.
  Optional arguments are listed between parenthesis.  See also under
  National Language Support.

     GetKey (variable)
        Indefinitely wait until a key is pressed and store it in the
        variable.



     WaitForKey duration (command)
        Wait until a key is pressed for no more than duration seconds.
        If no key has been pressed after the given time, evaluate the
        command.  Otherwise, leave the key in the keyboard buffer.  See
        also the paragraph on the format of durations.


     Input (variable (max-length))
        Read a return-terminated string from the keyboard and store the
        result string in variable (without the terminating return). If
        max-length is given, do not allow the user to enter more than
        this number of characters.

        See also GetPasswd under Security-related commands.


     OnKey
        Setup a key handler that will automatically evaluate the given
        command when the key "c" is pressed (except is explicitely
        waited by a GetChar or an Input command). If the string
        "default" is used instead of a single character, the command is
        executed if any other key is pressed.


  5.1.8.  Text output commands

  This section lists commands used to perform regular text output.  All
  these commands can be used in graphic mode also, with the same
  behaviour (except that text mode provides 80x25 characters while
  graphic mode provides 100x37, because graphic mode characters are of
  size 8x16).  Optional arguments are listed between parenthesis.  See
  also under National Language Support.

     Print
        Print the specified string/expression at current cursor position
        and using current text attributes, then move the cursor.  Add
        "\r\n" to the end of the string to go to the next line.


     TextAttr fg-color bg-color
        Setup the text attributes. One can also put a single numeric
        value representing both colors and defined as 16*bg-color+fg-
        color.

        If you need more fantasy, you can use LoadFont. See under
        National Language Support.


     At line,col (command)
        Move the cursor position to the specified position and evaluate
        the command if provided.

        Example: At 10,20 Print "Gnats and rats !"



     Clear (color (pattern-char (top,left,bottom,right)))
        Fill the given text area with the given pattern-char (either a
        string or the decimal ascii code). The area defaults to the full
        screen, the pattern char defaults to the full block (ASCII dec
        219) and the color defaults to black (clear screen). Move the
        cursor to the upper left corner of the cleared area.

     BpMenu backward compatibility commands


          .ATT (<attribute>)
          .CLS (<attribute>)
          .DEF <key> (<timeout_val>)
          .KEY <key> <filename>
          .POS ((<x>) <y>)
          .PWD <key> <cpasswd>
          .WLN (<text>)
          .WRT <text>



     See InCom's manual for more infos. We wrote some time ago a program
     program for editing menu files using this syntax, but it is
     preferable to make your menus using the new explicit syntax.  Note
     that the .PWD command is not implemented because we do not now the
     password crypting algorithm used by InCom GmbH.


  5.1.9.  Graphics output commands

  This section lists commands used to perform graphic-mode output.  For
  the functions listed in this section, coordinates are given in pixels.
  You can also use all text output commands (see above) in graphic mode.
  Optional arguments are listed between parenthesis.

  Note that the graphic mode is automatically turned on whenever a
  graphic command is used, unless the variable VESA is set to "OFF".

     InitGraph
        Turn on VESA graphics (800 pixels width, 600 pixels height, 256
        colors).  The origin is on the upper-left corner of the screen
        (0 0).  VESA graphics may hang some computers under Windows 95.
        Run MrBatch with the -v option to avoid such problems.


     CloseGraph
        Close VESA graphic mode and go back to text mode.


     DrawBar x-pos y-pos width height color
        VESA graphics. Draw a filled bar of the given size and colors.


     DrawWindow x-pos y-pos width height (bg-color (title-color))
        VESA graphics. Draw a window of the given size and colors. The
        background color defaults to LightGray and the title color
        defaults to Blue.


     Drawtext x-pos y-pos
        VESA graphics. Draw the text string at the given position with a
        transparent background. The color defaults to text foreground
        color.


     DrawGif
        VESA graphics. Load the given GIF-87a file and draw it on the
        screen.  The file can be interlaced, but must be in GIF-87a (not
        GIF-89a).  The image size should be no more than 800x600 with
        256 colors.  The GIF position defaults to the top left corner of
        the screen (0 0).

        The color-strategy defines the allocation of colors in the
        palette when more than 256 colors are needed (for instance when
        two 256 colors GIF files are displayed simultaneously):

     ╖  Best-Colors  use best possible colors for the most recent GIF

     ╖  Spare-Colors try to avoid allocating colors, change existing
        colors

     ╖  Share-Colors try to avoid allocating colors, use existing colors

     ╖  Reuse-Colors allocate no new color, only use existing colors

        The default strategy is Best-Colors.


  5.1.10.  Security-related commands

  This section lists commands that help you authenticate a user.
  Optional arguments are listed between parenthesis.

  Some of these functions cooperate with a Security gateway, that you
  should first install. See the section on Special TFTP servers for more
  infos.

     GetPasswd (variable (max-length))
        Same as Input, but echo stars instead of the typed characters.


     Crypt
        Apply the Unix crypt function to the given 8-chars text and
        store the resulting crypted string into variable. The "salt" is
        usually a two-character string that will be found as the first
        two characters of the crypted string.

        Note that Unix crypt is a one-way function. It is not possible
        to decode the crypted string. One can only try to crypt another
        string with the same salt and compre the resulting crypted
        string.


     DESCrypt
        Crypt the given text using the given 8-chars key and store the
        result as an hexadecimal string in variable.


     DESDecrypt
        Decrypt the given hexadecimal string using the given 8-chars key
        and store the result in variable.


     MD5
        Compute the MD5 checksum of the given text and store it as an
        hexadecimal string in variable. Can be used as an alternative to
        the Unix crypt function to check for passwords bigger than 8
        characters.


     CheckUser
        Connect to the $Security-Gateway and check if the given user
        exist in the given radius domain and uses the specified
        password.  If the domain is "Unix", use the Unix user/password
        definition on the security gateway. For any other domain, use
        the security gateway domain definition file to determine the
        real Radius or NT domain to check.

        Set the value of $Security-Check to "PASSED" or "FAILED".  The
        password do not transit in clear on the network.


  5.1.11.  Disk-related commands

  This section lists commands for preparing the hard-disk.  Optional
  arguments are listed between parenthesis.

     GetPartitions variable (disk)
        Read the partition table(s) for the given disk and store it as a
        string into the given variable. The result string is a space-
        separated list of Type:Size, where

     ╖  Type is FAT16, EXT, BIGDOS, NTFS, FAT32, FAT32-LBA, BIGDOS-LBA,
        EXT-LBA, LINUX-SWAP, LINUX-EXT2 or the decimal filesystem id for
        unknown types.

     ╖  Size is the size of the partition in megabytes.


     SetPartitions
        Setup the partition table(s) to the content of the string. The
        format used is the same that for GetPartitions. This command
        also reset all boot flags (hint: use SetBootPart).

        If you want to use extended partitions, remember that they begin
        after each four partitions. You can use EMPTY to leave a free
        entry in the partition table. For instance, if you want to setup
        a primary dos partition of 100 MB and a logical dos partition of
        400 MB, you must execute

                SetPartitions "BIGDOS:100 EXT:400 EMPTY EMPTY BIGDOS:400"




     GetBootPart variable (disk)
        Get the partition number with the boot flag turned on (DOS says:
        the activated primary partition) and store it to the variable.
        The first partition is numbered 1.  If no partitions has the
        boot flag turned on, answers zero.


     SetBootPart partition (disk)
        Set the boot flag to the given partition. The boot flag let the
        master boot record (MBR) choose which partition to boot on.  The
        first partition is numbered 1.


     Blank partition (disk)
        Fill the given partitions with zeroes. Can take quite a lot of
        time for big partitions. Do not format the partition for any
        operating system. See also Clean.


     Clean partitions (disk) (
        Fast-format the given partition(s) according to the type
        declared in the partition table. If a label is given and the
        filesystem supports it, setup the partition label. For a
        paranoiac full format, call Blank on the partition first.

        Clean is supported for (FAT16) BIGDOS, FAT32, EXT, LINUX-EXT2
        and LINUX-SWAP partitions. To clean the master boot record
        (MBR), use Clean 0.

        Clean should be used on data partitions and on MBR/EXT
        partitions.  It is totally useless to clean a partition before
        unzipping a filesystem on it using FullUnzip.

     FullUnzip
        Decompress a full disk archive to the given partition,
        overwriting any existing file (clean-up on the fly).

        FullUnzip is supported for (FAT16) BIGDOS, FAT32 and LINUX-EXT2.
        Unfortunately, images restored from FAT32 do not seem to be
        bootable, although all files are restored correctly. This should
        be fixed in a future release.

        This commands turn on VESA graphics to display a progress
        banner, unless VESA has been turned OFF.


     IncrUnzip
        Decompress an incremental disk archive to the given path. Files
        in the archive replace those with the same name on the target
        path, but other files are not deleted.

        IncrUnzip is supported for (FAT16) BIGDOS, FAT32 and LINUX-EXT2.
        This command is far less efficient than FullUnzip since the
        existing filesystem structure must be preserved. However, it
        avoids multiplying the number of different disk images by
        storing the differences only.


     FileUnzip
        Uncompress a file previously compressed with MrZip FileZip
        command.  The file is validated by a 32-bits CRC.


     Copy
        Copy the source file to the destinaton file, byte-to-byte.  Can
        be used after a FullUnzip for instance to update configuration
        files from the server without rebuilding the image.  Better to
        use FileUnzip for big and easy-to-compress files.


     Append
        Copy the first, then the second file to the destination file,
        byte-to-byte.  Can be used on arbitrary large files.  The
        destination file cannot be one of the two source files.


     Patch
        Read the source file and perform variable substitution before
        writing it to the destination file. The interpretation of
        characters above ASCII 127 depends on the value of $IsoLatin.

        By default, variables are recognized when prefixed by "${" and
        postfixed by "}". This can be changed to any other non-empty
        string.  remember that if you want to use a dollar sign within
        the prefix or suffix, you must escape it or it will get macro-
        evaluated. For instance, if you want to explicitely use the
        default prefix and postfix, use:

                Patch "source-file" "dest-file" "\${" "}"




     MkDir
        Recursively create directories from the root to the given full
        path.  If the path already exists, this command has no effect.



     Delete
        Remove the given file. The file must exist.


     DelTree
        Recursively remove all files and directories under the given
        path, and remove the directory itself.


  5.1.12.  Boot commands

  This section lists commands for continuing the boot process.  Optional
  arguments are listed between parenthesis.

     HideBootProm
        Restore the memory and the interrupt vectors allocated by the
        bootprom.  All attempts to make TFTP transfers will fail after
        calling this command.  It is usually a good idea to call this
        command before HdBoot, or you might run short of memory under
        DOS/Windows. This command is implicitely called by FloppyBoot.

        Note that although this function restore all vectors
        "officially" rerouted by the BootProm, it does not seems to
        restore everything.  But it works well enough for DOS and
        Windows.


     LoadRamDisk
        Load a floppy disk image into the extended memory and redirect
        the BIOS Disk Services to make floppy disk calls use this image
        instead. This command implicitely calls HideBootProm. Call
        FloppyBoot to boot on the ramdisk you just loaded.

        This kind of ramdisk may not be as robust as what you get when
        you use the TFTPBoot command. The only advantage is that it only
        steals a few hundred bytes of conventional memory instead of the
        >64 KB reserved by the TCP/IP BootPROM. Warning, nothing secures
        the extended memory in which the ramdisk resides.  There is no
        way to uninstall such a ramdisk.


     LoadZRamDisk
        Do the same as LoadRamDisk, but for an image that has been
        compressed using MrZip FileZip command. Compressed ramdisks are
        protected against data corruption (and uncomplete download) by a
        byte count and a 32-bits CRC.


     TFTPBoot
        Chain to another boot file (for instance a floppy image made
        with InCom's BpShell program). See the file referencing
        conventions for accessing a file on another TFTP server.


     FloppyBoot
        Hide the Boot ROM, load the floppy disk boot sector and boot on
        it.  Unfortunately, this command does not seems to work well
        enough for LDLINUX.SYS (used on RedHat Linux setup disk) to
        work.


     HdBoot (disk)(:partition)
        Load the given boot sector and boot from it. The disk default to
        zero, the first hard disk, and the partition defaults to zero,
        ie. the master boot record. You can boot from any partition, but
        be warned that Windows 95 may not let you boot a partition that
        has not been set as the boot partition (hint: use SetBootPart).

        This command does not implicitely call HideBootProm, so you
        might want to call it before.


     LinuxBoot
        Load the given kernel and ramdisk into the high memory, setup
        the command line and boot the kernel. It is a good idea to put
        at least a minimal command line with the location of the root
        filesystem (like "root=dev/hda1"/). If you are using a linux
        system that heavily relies on lilo (like RedHat Linux 5.1), it
        may be necessary to add to the command line something like
        BOOT_IMAGE=linux. Note that the kernel can be loaded by TFTP
        (automatically cached on the hard disk) or directly from the
        target root partition.

        This command works for small and big kernels (zImage and
        bzImage).


  5.1.13.  National language support

  This section lists commands related not national language support.
  Optional arguments are listed between parenthesis.

     RemapKeys
        National keyboard support. Remap given keys to other characters.
        For instance, to swap the Y and Z keys, use

                Remapkeys "yzYZ" "zyZY"


     It is a good idea to use the quoted octal notation when using char¡
     acters not included in the minimal ASCII character set, in order to
     avoid a dependency to the iso-latin modal settings.

     For international keyboards, there are two keys that produce a
     backslash in non-remapped (US) mode. Each of them can be
     independantly remapped, thanks to the fact that BpBatch sees one of
     them as a key answering ASCII code 252 (octal) or ASCII code 335
     (octal) when shifted.

     If you send me a sample script that does keyboard mapping for your
     national keyboard, I will make it available under
     http://cuiwww.unige.ch/info/pc/remote-boot/soft/sample-scripts To
     help you make your own keyboard mapping, I suggest pressing all
     special keys without remapping the keyboard and writing down the
     character they produce.  These will be the original-keys. The
     remapped-keys simply are the key you would have liked to see, in
     the same order. If some keys (either original or remapped) produce
     characters above ASCII dec 127, use the quoted octal notation. You
     can easily get the octal code for any given character by looking in
     the ASCII table of HelpPC for instance (HelpPC is a shareware
     hypertext on-line help program by David Jurgens).


     RemapAltkeys
        National keyboard support. Remap the given keys when ALT is
        depressed For instance, to map Alt-2 to the ampersand sign, use

                RemapAltKeys "2" "@"


     Note that dead keys are not supported.

     LoadCodePage
        Load and activate the given binary Codepage file.  Codepages are
        used for the translation of Unicode characters (present on VFAT
        valumes for instance) into 8-bits characters.  If you do not
        have the right Codepage loaded, you will get FAT warnings while
        accessing the filesystem when special characters are encountred.

        All binary codepage files are available at
        http://cuiwww.unige.ch/info/pc/remote-boot/soft/codepage.zip

        The default codepage is 850, a reordered superset of ISO-
        Latin-1.  If you load a more exotic codepage, you should usually
        turn the variable $IsoLatin to "off" or you might get
        meaningless implicit conversions. Moreover, if you want to
        display exotic characters, you should also load the proper
        screen font (use "LoadFont").


     LoadFont
        Load and activate a VGA/VESA font, both in text and graphic
        mode.  The font file must be a binary file of 16
        bztes/characters (8x16 bitmap). This command can be used for
        National Language Support as well as for Fantasy support.

        An archive with several fantasy fonts is available at
        http://cuiwww.unige.ch/info/pc/remote-boot/soft/fonts.zip.  This
        archive also contains a program to extract fonts for your
        codepage from the DOS .CPI file.


  5.1.14.  Commands specific to MrZip


     Source...

          Source (i)archive "filename"
          Source path "path"



     Set the source for the archive manipulation to the given
     (incremental) archive file or disk path.


     Dest...

          Dest (i)archive "filename"
          Dest (i)dump
          Dest path "path"



     Set the destination for the archive manipulation to the given
     (incremental) archive file, dump or disk path. To control the
     quantity of data displayed during dump, use the $DumpFormat special
     variable.


     FileZip
        Compress a file for further decompression with FileUnzip or for
        using as ZRamDisk. The file is validated by a 32-bits CRC.


     Filter...


          Filter -"pattern"
          Filter +"pattern"



     Avoid/allow files and directories matching the given pattern
     (wildcards allowed) to be included in the archive. The pattern is
     matched agains the full pathname. By default, all files are
     included in the image.  You only need to explicitely allow files
     that where cancelled by a filter.  Each negative filter has its own
     positive filter (allowed) sublist.

     For DOS/Windows images, you will typically use

             Filter -"*.swp"
             Filter -"temp/*"


     and for Unix images, you will typically use

             Filter -"var/log/*"
             Filter -"tmp/*"




     CopyArchive
        Start the archive manipulation operation, according to source,
        destination and filter settings. Except in a few circumstances,
        you will probably use the shortcut below instead of explicitely
        calling CopyArchive.  One circumstance in which you will use
        CopyArchive explicitely is when you want to change the
        fragmentation of an image, as follow:

                set FragmentSize="30 MB"
                Source archive "original.imz"
                Dest archive "refragmented.imz"
                CopyArchive




     FullZip
        Shortcut for

                        Source path "path"
                        Dest archive "full-archive"
                        CopyArchive


     You should usually first setup filters.


     IncrZip
        Shortcut for

                        Source path "path"
                        Dest iarchive "incr-archive"
                        CopyArchive




     FullDump
        Shortcut for

                        Source archive "full-archive"
                        Dest dump
                        CopyArchive




     IncrDump
        Shortcut for

                        Source iarchive "incr-archive"
                        Dest dump
                        CopyArchive




     XCopy
        Shortcut for

                        Source path "srcpath"
                        Dest path "dstpath"
                        CopyArchive




  5.2.  NoBreak.sys

  Nobreak.sys is a very small (about 350 bytes only) driver that you
  include at the beginning of your config.sys. Its goal is to secure the
  boot process, until the user is logged in.  DOS provides a setting for
  this (namely BREAK=OFF), but it is not drastic enough, and has almost
  no effect in the autoexec.bat.  Our driver works by modifying the
  scan-code of the key pressed when a break is requested, directly at
  the BIOS level.  This way, no program at all can receive a break until
  break is enabled again.

  The driver must be loaded from the config.sys (or using the devlod
  program from Undocumented DOS). Afterwards, break can be enabled by
  sending Yes to the NOBRK pseudo-device, and disabled again by sending
  No (in fact, only the first character, Y or N is significant).

  As this driver relies on the BIOS, it does only work for DOS and
  Windows 3.1.  Windows 95 has its own low-level keyboard handling
  routines.

  Assembler source code is available.


  6.  Special TFTP Servers

  As the only network support available in the TCP/IP BootPROM is TFTP,
  there is a special interest in enhancing TFTP servers for providing
  new capabilities.


  6.1.  Incom Enhanced TFTP Server

  InCom GmbH distributes with the TCP/IP BootPROM an enhanced TFTP
  server that can send packets of up to 1408 bytes instead of the
  standard 512 bytes.  This is a great enhancement that you should use.
  This server is available on the TCP/IP Bootprom Utility disk for
  Solaris, Windows and as Netware NLM.


  6.2.  Linux Enhanced TFTP Server

  We built a modified version of Linux TFTP server that acts as InCom
  enhanced TFTP server. Basically, we simply changed the packet size
  from 512 to 1408 bytes and the port from 69 to 59.  It is available
  from http://cuiwww.unige.ch/info/pc/remote-boot/soft/etdtpd.tar.gz.


  6.3.  The Security Gateway

  We wrote a special TFTP server that serves as security gateway for
  authenticating users. This server runs under Linux or Solaris, and can
  authenticate users according to a Unix password database (NIS and
  shadow passwords are supported), a Windows NT (or Samba) server or a
  Radius server.  It is available from
  http://cuiwww.unige.ch/info/pc/remote-boot/soft/stdtpd.tar.gz, with
  source and precompiled binaries.  The precompiled binaries do not
  include NT password encryption as we cannot distribute libdes but
  compilation is straightforward.

  In order to use the security gateway, you just have to setup a trivial
  security domains configuration file that describes to which
  authentication server each logical security domains maps (the Unix
  domain implicitely maps to the server Unix password database). This is
  a sample configuration file:


       ______________________________________________________________________
       #
       # STFTPD configuration file
       #
       # This file specify the server of the "security domains". Two types of
       # authentication servers are supported : radius or winnt (winnt includes
       # NT Server and Samba)
       #
       # Format of radius servers
       # radius        <domain>        <serveraddress>         <secret>
       #
       # secret is the secret word as specified in your /etc/raddb/clients file
       #
       # Format of SMB servers
       # winnt         <domain>        <serveraddress>         <netbiosname>
       #
       # netbiosname is the NETBIOS name of your server
       #
       # Examples
       radius         sec-dom-rad     radiusserver    testing123
       winnt          sec-dom-nt1     192.168.1.1     NTSERVER1
       winnt          sec-dom-smb     samba           SAMBA1
       ______________________________________________________________________




  Note that if you are using Samba, you must set security = user.

  You can also provide to the security server a file containing a list
  of users which are not allowed to log on (for which the check will
  fail anyways).


  6.4.  The Broadcast TFTP Server

  We wrote a special TFTP server that implements a home-made Broadcast
  variant of TFTP. Using this server, we were able to download images to
  25 clients on a heavily loaded 10 Mb ethernet network at 6 Mb/s (it is
  more efficient than the regular TFTP because it does not need to
  acknowledge each packets).  This server runs under Linux or Solaris.
  It is available from http://cuiwww.unige.ch/info/pc/remote-
  boot/soft/btdtpd.tar.gz, with source and precompiled binaries.

  As the TCP/IP bootprom does not support this protocol, our solution
  consist in booting a tiny ramdisk-based linux system using the tools
  described in this document, and running the Linux version of MrBatch
  which has built-in support for Broadcast TFTP. A simple batch file can
  the download all files to the cache in a few minutes, simultaneously
  on all client computers.  You do not need to install Linux yourself to
  use this package, except if you have exotic hardware and cannot
  directly use the kernel provided in the package.

  The process works as follow. First, you startup the broadcast server
  manually, giving the number of expected client computers as argument
  (remember, this procedure is not to be used every day but only when
  you changed an image and want to ensure it is immediately uploaded to
  all your client computers). Then, you turn on all client computers,
  which will run the following BpBatch script:


       ______________________________________________________________________
       #
       # This batch is run by bpbatch to launch a mini-linux using an initial
       # ramdisk, which will then run mrbatch under linux.
       #
       # The broadcast TFTP protocol only works with the Linux implementation of
       # mrbatch, because of the lack of broadcast support in the bootprom itself.
       #
       # 1. Setup a tiny partition, to let a lot of space for the cache
       setpartitions "BIGDOS:50"
       # 2. Clean the MBR
       clean 0
       # 3. Run a Linux Kernel with initrd (Initial Ramdisk) supprt, and use
       #    bcastrd.gz as the initial ramdisk (will be mounted root and then
       #    executed via /linuxrc). See initrd.txt for more details about
       #    initial ramdisks. You don't have to specify a root device (second
       #    parameter is null) to the kernel, it will use the initial ramdisk.
       linuxboot "linux.krn" "" "bcastrd.gz"
       # 4. The initial ramdisk will run dhcpcd to setup networking using DHCP.
       #    It will then run mrbatch -w bcastlx
       ______________________________________________________________________




  The initial ramdisk contains:

  ╖  dhcpcd, a DHCP client used to setup networking

  ╖  mrbatch

  ╖  linuxrc, a little wrapper automatically started by initrd and that
     starts dhcpcd then mrbatch.

  ╖  usr/lib/terminfo/l/linux, used by MrBatch

  ╖  dev/*, devices needed to run Linux and mrbatch

     All programs are statically linked and stripped, to avoid libc.so
     which is really huge. The resulting ramdisk is Gzipped and takes
     less than 300 KB. The kernel itself takes 450 KB (with many network
     cards and initrd support).  When Linux is up and running, MrBatch
     is called with the following script (that you should edit for your
     needs):
       ______________________________________________________________________
       # This file is executed when mrbatch is launched by the initial ramdisk
       # bcastrd.gz
       # It's main purpose is to "broacast copy" files to the cache
       #
       # 1. Be verbose
       showlog
       # 2. Don't want a "press a key"
       set pauselog="OFF"
       # 3. Set partitions at their final values.
       #    Important: Since you will copy files into the cache to be used in future
       #    boot, you need to specify the same partitions as in the future boots.
       setpartitions "BIGDOS:1024"
       # 4. Clean the CACHE partition
       clean -1
       # 5. And the copy files into the cache, using the Broadcast TFTP protocol
       #    (port 99)
       #
       # You can use the script "as is", but you surely need to modify the following
       # line ! In our example, we download the file mblinux.imz, which is the image
       # file for our installation of Linux.
       copy "$BOOTP-Server-IP@99:mblinux.imz" "{:-1}mblinux.imz"
       ______________________________________________________________________




  When the transfer is done, you can simply turn off all client comput¡
  ers and change their initial boot script to your favorite menu.