Linux Remote-Boot mini-HOWTO:      Configuring Remote-Boot
 Workstations         with Linux, DOS, Windows 95/98 and Win
 dows NT
 Marc Vuilleumier Stckelberg, David Clerc
 v3.19, February 1999

 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
 [email protected].
 ______________________________________________________________________

 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 (FAQ)

 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).

 Version 3.14 added minor enhancements and some corrections. We fixed a
 problem with the terminal under RedHat 5.1, and another problem in the
 syntax of the "if" command. We added some features suggested by the
 Laboratori de Clcul de la Facultat d'Informtica de Barcelona (LCFIB)
 :

   A new APM variable let you know if your system support the Advanced
    Power Management (i.e it supports the poweroff command).

   A "beep" command.

   A new parameter to DrawWindow, to include a title at the window
    creation. You can now do DrawWindow 200 200 400 200 "Title".

 Version 3.15 added full VESA support. BpBatch now support several
 video modes, to accomodate old computers not being able to display
 800x600 graphics. A new parameter has been added to InitGraph to
 specify the video mode, and a list of detected video mode can be
 retrieved from the new VESA-Modes variable.
 Version 3.16 fixes the following bugs:

   "Malloc failed" during the Fullunzip process of a multiple
    fragments image.  Many thanks to Christian Meyer for his
    collaboration.

   A bug which prevented the linux version of MrBatch to properly
    fullunzip images. This bug was located in the low-level functions
    of MrBatch, so it may fix other problems encountered in the linux
    version of MrBatch.  Many thanks to Jeff Teeters for his
    collaboration.

   An error in the codepage translation tables. This bug was found by
    the Laboratori de Clcul de la Facultat d'Informtica de Barcelona
    (LCFIB).  You can find the bug report in the BpBatch forum.

 Version 3.17 adds some minor features and fixes bugs:

   Fullunzip was turning Extended Memory off

   Booting on the RedHat boot disk now works

   When extracting images with a large number of directories, the
    resulting FAT file system was corrupted.

   We added retries to text TFTP transfers. BpBatch will now retry
    three times before saying "Could not transfer the file".

   Timestamps are now correctly updated in FAT. (thank to Francis
    Chan)

 Version 3.18 fixes a bug with the IncrUnzip function. Thanks to Gary
 Pike for its collaboration.

 Version 3.19 fixed a bug in the error handling of the delete command
 on ext2fs, as well as the inappropriate handling of names starting
 with A: under Linux. The following new features were also added:

   A new if valid disk:partition syntax can be used to check if a
    partition has been formatted

   FAT32 disk images are now fully functional (they now boot properly)

   Linux EXT2 partitions bigger than 2 GB are now supported

   Linux Swap partitions bigger than 128 MB are now supported (this
    feature needs a recent kernel, at least 2.1.x)

   FullUnzip is now also possible without a cache partition, by
    setting CacheNever to "ON". This might be usefull for a unique
    installation, but is not recommended in general is it results in a
    high network load.

    Thanks to Ruben Schattevoy for its help and contributions to this
    release.


 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
 [email protected].  And if you experience
 problems while reproducing this configuration, have a look at these
 pages !

   http://www.br.fgov.be/RESEARCH/INFORMATICS/info/bootp.html, by
    Alain Empain of the Belgium National Botanic Garden.  Many useful
    sample scripts, and a nice PERL program to automatically generate
    graphic menus and corresponding HTML documentation from a higher
    level description.

   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.

   http://www.etse.urv.es/~larinyo, in spanish, by  Lluis Arino, of
    the Escola Tecnica Superio d'Enginyeria, Spain.

 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 PXE Boot ROMs with version before 0.99 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 :-(. Intel has recently fixed
    this bug, and if you bought your computer after June 1998, you
    surely have a corrected PXE implementation.


 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).  Then, take a look in the BpBatch forum.
 Perhaps someone else had the same troubles as you have, and the answer
 can be found in the forum.  Forum's URL :
 http://cuiwww.unige.ch/info/pc/remote-boot/forum/.  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
 [email protected] or [email protected].
 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. You can list the available video modes
 using Echo "$VESA-Modes". To display your image try 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. To insert a title when you create a new
 window, try DrawWindow 200 200 300 150 "My Window".  When you are
 tired of graphic mode, simply type CloseGraph.

 Note on graphics : by default, all graphical routines work in the
 800x600 VESA mode (with 256 colors), which is the first field of the
 VESA-Modes variable. If you want to use a different video mode, change
 the variable in order to have the requested video mode as the first
 field of the list.

 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 "Identity check"
      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 blue "Congratulations"
      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.

 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 (FAQ)

 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 three 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,
       or because of incompatible protocol.

       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).

       Incompatible protocol is caused by using a standard TFTP server
       (typically the one built-in in your UNIX server) while asking
       BpBatch to work with enhanced TFTP. If you use a standard TFTP
       server, you should remove the .P extension (see the explanation
       in the next question).


    The computer hangs instead of downloading/unzipping (1)
       If you are using Incom's TFTP server, try to add -s 1408 59 to
       the command line. If you are not using an enhanced TFTP server,
       remove the .P extension from BpBatch filename on the server and
       in bootptab.

       Detailed explanation : this problem occurs if you did not setup
       an extended TFTP server but you used bpbatch.P as the
       bootfilename DHCP/BOOTP tag. BpBatch will indeed try to connect
       to an extended TFTP server when the bootfilename ends with a .P
       extension. To solve this problem, you can either remove the .P
       extension at the end of the bootfilename (it will tell BpBatch
       to use standard TFTP) or install an extended TFTP server.  The
       only supported extended TFTP server today is the one provided by
       Incom. You can find compiled binaries on their web site, or on
       our distribution directory. For Incom's TFTP server to properly
       work with the extended TFTP feature, you must add -s 1408 59 to
       the command line.

    The computer hangs instead of downloading/unzipping (2)
       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 has been fixed in the 9th of August version of
       MrBatch/MrZip.  There was a problem with a new version of
       ncurses which has been released with RedHat 5.1.

       MrZip has been linked to the version 3.0 of libncurses. You can
       use other versions of libncurses only if they are newer than
       version 3.0. To use a newer libncurses, all you have to do is to
       create a soft link from libncurses.so.3.0 to your
       libncurses.so.xx file.  With RedHat 5.1, you can use the
       following command : cd /usr/lib ; ln -s libncurses.4.2
       libncurses.3.0 You can also download a version recent version of
       mrzip/mrbatch. Starting from the 10/25/98, mrbatch is now
       compiled under RedHat 5.1.

    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...).

    I can not access other mode than the default 800x600 VESA mode
       You should first display the contents of the VESA-Modes
       variable, to see if your hardware support the mode you would
       like to use.  Then, try one of the two ways to select a special
       VESA mode :

      InitGraph "mode": Try InitGraph "1024x768", and then run the
       graphical primitive you are interested in (e.g DrawGif).

      VESA-Modes: The first field of the VESA-Modes variable is the
       name of the default mode. If you change the VESA-Modes variable,
       all graphical primitive will use the mode you specified.

    BpBatch prints a
       We corrected a bug in the memory allocation functions of
       BpBatch. You should make sure that you have a version of BpBatch
       which has been released after september the 22nd 1998.

    Fullunzip using the Linux version of MrBatch always fails
       We corrected this problem in the 09/22/1998 release.

    Scandisk says my disk is corrupted
       The 10/25/98 release did correct a problem with large images.
       Try to download a recent version of BpBatch.

    My RedHat boot floppydisk does not work with FloppyBoot
       This bug has been corrected in the 10/25/98 release.

    My FAT32 disk image does not boot properly
       This bug has been corrected in the 02/09/99 release.


 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

      $VESA-Modes gives the list of all available VESA modes.  The
       first entry of the list is the default mode, which is used when
       no parameter is given to InitGraph.  Note: if VESA="OFF", this
       variable is blank
      $APM    is set to "ON" if your computer supports Avanced Power
       Management. If $APM is "ON", you can use the command PowerOff to
       turn your computer off.  Default: depends on your hardware

      $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.


    Beep
       Make a sound. This command is equivalent to Echo "\007".


 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>
         If (not) valid <disk>:<partition> <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.  The 8th form tests if the given
    partition is valid (i.e. formatted). This form is only supported by
    BpBatch versions after February 1999.


    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.  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.

       You can request a specific video mode if you use the parameter
       "mode" This parameter is optional: if you do not specify any
       value, the video mode will be taken from the first field of the
       VESA-Modes variable.

       Valid modes are :

      640x480    =>  640 by 480 pixels, 256 colors

      800x600    =>  800 by 600 pixels, 256 colors (default mode)

      1024x768   =>  1024 by 768 pixels, 256 colors

      1280x1024  =>  1280 by 1024 pixels, 256 colors

       The VESA-Modes variable lists the video modes supported by your
       hardware.

       Example: InitGraph "640x480"


    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 (bar-color)) (
       VESA graphics. Draw a window of the given size and colors. The
       background color defaults to LightGray and the title-bar color
       defaults to Blue.  If you include a title string and a color,
       this text will be displayed in the title bar.


    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 fit in the selected video mode.
       You cannot load a 1024x768 GIF file when you selected a 640x480
       mode.  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.

       See SetPartitions for more informations about partitions.


    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).

       The main partition table in the master boot record (MBR) has
       only four entries. Moreover, DOS and Windows accept only ONE FAT
       partition (called the Primary partition, C:) in the main
       partition table. Any supplemental FAT partition should be nested
       in an extended partition (and is thus called a Logical
       partition). If we give numbers 1-4 to the partitions described
       in the MBR partition table and numbers 5-8 to the partitions
       described in the first extended partition, the definition of two
       FAT partitions would work by defining partition 1 as FAT,
       partition 2 as EXT and partition 5 as FAT. Partitions 3,4,6,7
       and 8 should be marked as UNUSED. The same scheme can be used
       recursively to define more than two FAT partitions: nesting
       another extended partition in partition 6 and adding a logical
       FAT partition in partition 9.

       In the most strict interpretation of DOS specifications, that
       means that entries 3 and 4 of the partition tables are never
       used. In practice, some versions of DOS and some other OS are
       able to use more than two partitions per partition table, but
       there is no clear rule.  On this side, BpBatch is rather
       flexible in its interpretation of partition tables, it can often
       understands things that OSes cannot.

       One universal rule is that there should never be more than one
       extended partition per partition table, otherwise the partition
       numbering scheme breaks down.

       If you want to try funny configurations, make your own
       experiments, but don't complain if the OS does not recognize
       your partitions. The only way it is guarantee to work is to use
       the primary partition to store the OS boot partition, and to
       nest all other partitions, one at a time, in extended
       partitions.

       Example of extended partitions :

               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.

       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.


    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.