  Diskless Nodes HOW-TO document for Linux
  Robert Nemkin        buci@math.klte.hu , Al Dev (Alavoor
  Vasudevan) - Maintainer of this HOWTO alavoor@yahoo.com ,
  Markus Gutschke markus+etherboot@gutschke.com , Ken Yap
  ken.yap@acm.org , Gero Kuhlmann gero@gkminix.han.de
  v20.0, 28 Mar 2001

  This document describes how to set up a diskless Linux box. As tech
  nology is advancing rapidly, network-cards are becoming cheaper and
  much faster - 100 MBits ethernet is standard now and in about 1 to 2
  years 1000 MBits i.e. 1GigBits ethernet cards will become an industry
  standard.  With high-speed network cards, remote access will become as
  fast as the local disk access which will make diskless nodes a viable
  alternative to workstations in local LAN. Also diskless nodes elimi
  nates the cost of software upgrades and system administration costs
  like backup, recovery which will be centralized on the server side.
  Diskless nodes also enable "sharing/optimization" of centralised
  server CPU, memory, hard-disk, tape and cdrom resources. Diskless
  nodes provides mobility for the users i.e., users can log on from any
  one of diskless nodes and are not tied to one workstation.  Diskless
  Linux box completely eliminates the need for local floppy disk, cdrom
  drive, tape drive and hard-disk. Diskless nodes JUST has a network
  card, 8MB RAM, a low-end cpu and a very simple mother-board which does
  not have any interface sockets/slots for harddisks, modem, cdrom,
  floppy etc..  With Diskless linux nodes you can run programs on remote
  Linux 64 CPU SMP box or even on Linux super-computer!  Diskless nodes
  lowers the "Total Cost of Ownership" of the computer system.  This
  document is copyrighted by Robert Nemkin and other authors as listed
  above. Copyright policy is GPL.  Thanks to Bela Kis        bkis@car
  tan.math.klte.hu for translating this initial document v0.0.3 (which
  was a mini-howto) to English.
  ______________________________________________________________________

  Table of Contents



  1. Buying is cheaper than building!

  2. Diskless Computer for Microsoft Windows 95/NT !!

     2.1 VMWare package
     2.2 Plex86 package
     2.3 VNC package from AT and T

  3. Advantages of Diskless Computer

  4. Quick Steps to implement Diskless Nodes

     4.1 Linux Terminal Server Project - LTSP

  5. Building EEPROM Burner

     5.1 What is this ?
     5.2 Supported EEPROMs
     5.3 Schematics and pinouts
     5.4 Construction
     5.5 Jumper setup
     5.6 Low-justification of 24-pin EEPROM devices
     5.7 Parts List
     5.8 If you have already built EEP-0.1
     5.9 How to build the software
     5.10 Usage
     5.11 Schematic Diagram in ASCII

  6. EPROM Burners and Memory chips

     6.1 Non-Volatile Memory chips
     6.2 List of EEPROM Burner manufacturers

  7. Introduction to Network Booting and Etherboot

     7.1 What is Network booting?
     7.2 How does it work
     7.3 Netbooting in Practice
        7.3.1 Bootp
        7.3.2 Tftp
        7.3.3 NFS root filesystem
        7.3.4 Burn EPROM
     7.4 Uses of Network booting
     7.5 For more information

  8. Redhat Linux configuration

     8.1 X-terminal

  9. LanWorks BootWare PROMs

  10. Etherboot

  11. Netboot

     11.1 Introduction
     11.2 Mailing list
     11.3 Netboot useful links

  12. Related URLs

  13. Copyright Notice

  14. Other Formats of this Document

  15. Topics for Academics and Universities
  ______________________________________________________________________

  1.  Buying is cheaper than building!

  Sometimes, buying a diskless linux computer will be cheaper than
  building!!  Checkout the following commercial sites, which are selling
  diskless linux network-cards and diskless computers. These companies
  do mass production of Linux Diskless computers selling millions of
  units and thereby reducing the cost per unit. Each and every fortune
  1000 companies in USA will be replacing the MS Windows PCs with
  diskless computers in near future as diskless linux computers can run
  both Linux and MS Windows 95 programs (via VMWare BIOS software).
  VMWare <http://www.vmware.com> is NOT a emulator but has BIOS which
  allows you to install Windows 98/NT as guest OS to linux. You can use
  the 'xhost' command and DISPLAY environment from diskless node to run
  Windows95/Linux programs. See 'man xhost' on linux.  You can also use
  Virtual Network Computing (VNC) to run Windows95/NT programs on linux
  diskless nodes. Get VNC from  <http://www.uk.research.att.com/vnc>


    Linux Systems Labs Inc., USA  <http://www.lsl.com> Click on "Shop
     On-line" and than click on "HardWare" where all the Diskless
     computers will be listed. Phone 1-888-LINUX-88.


    Diskless Workstations Corporation, USA
     <http://www.disklessworkstations.com>


    Unique Systems of Holland Inc., Ohio, USA  <http://www.uniqsys.com>

  Even if you buy diskless linux computer, you may be very much
  interested in reading this entire document.

  2.  Diskless Computer for Microsoft Windows 95/NT !!

  Since Microsoft Windows 95/NT DOES NOT support diskless nodes, there
  is an intelligent work-around to overcome this short coming.
  Microsoft corporation will be surprised !!

  2.1.  VMWare package

  Use the VMWare <http://www.vmware.com> BIOS software with Linux which
  can host the Windows 95/98/NT.  Linux will be the "host" OS and
  Windows 95/NT will be the "guest" OS.  VMWare <http://www.vmware.com>
  is NOT a emulator but has BIOS which allows you to install Windows
  95/98/NT as the guest OS to linux. Install the VMWare on Linux server
  and than install Windows 95/NT on VMWare.

  You can use the 'xhost' command and DISPLAY environment from any
  diskless node. See 'man xhost' on linux. At diskless node give -

  ______________________________________________________________________
          export DISPLAY=server_hostname:0.0
  where server_hostname is the name of the server machine. And start X-terminal with
          xterm
  ______________________________________________________________________


  Using VMWare <http://www.vmware.com>, Diskless linux computers can run
  both Linux and MS Windows 95 programs.  VMWare is at
  <http://www.vmware.com>.



  2.2.  Plex86 package

  There are other tools similar to vmware:

    Plex86 (open-source) at  <http://www.plex86.org>

    Wine (open-source) at  <http://www.winehq.com>

    Win4Lin at  <http://www.netraverse.com>

  2.3.  VNC package from AT and T

  You can also use the VNC (Virtual Network Computing) Technology from
  the telecom giant AT & T. VNC is GPLed and is a free software. Using
  VNC you can run Windows 95/NT programs on diskless linux computer but
  actually running on remote Windows95/NT server.  VNC is at
  <http://www.uk.research.att.com/vnc>

  3.  Advantages of Diskless Computer

  Diskless linux computer will become immensely popular and will be the
  product of this century and in the next century.  The diskless linux
  computers will be very successful because of the availability of very
  high-speed network cards at very low prices. Today 100 Megabit per
  second (12.5 MB per sec transfer rate) network cards are common and in
  about 1 to 2 years 1000 MBit (125 MB per sec transfer rate) network
  cards will become very cheap and will be the standard.

  In near future, Monitor manufacturers will place the CPU, NIC, RAM
  right inside the monitor to form a diskless computer!!  This
  eliminates the diskless computer box and saves space. The monitor will
  have outlet for mouse, keyboard, network RJ45 and power supply.

  The following are benefits of using diskless computers -

    Diskless Linux computers can run BOTH MS Windows 95/NT and linux
     programs.


    Total cost of ownership is very low in case of Diskless computers.
     Total cost of ownership is cost of initial purchasing + cost of
     maintainence.  The cost of maintainence is usually 3 to 5 times the
     cost of initial computer purchase and this cost is recurring year
     after year.  In case of Diskless computers, the cost of
     maintainence is completely eliminated!!


    All the backups are centralized at one single main server.


    More security of data as it is located at server.


    No need of UPS battery, air-conditioning, dust proof environment
     for diskless clients, only server needs UPS battery, A/C and dust
     proof environment.


    Noise is completely eliminated since diskless computer does not
     have Fan motor, and local harddisk. Only server makes lots of noise
     but it is enclosed in a server room.


    Protection from Virus attack - Computer virus cannot attack
     diskless computers as they do not have any hard disk. Virus cannot
     do any damage to diskless computers. Only one single server box
     need to be protected against virus attack. This saves millions of
     dollars for the company by avoiding installtion of vaccines and
     cleaning the hard disks!!


    Server can have large powerful/high performance hard disks, can
     optimize the usage of disk space via sharing by many diskless
     computer users.  Fault tolerance of hard disk failure is possible
     by using RAID on main server.


    Server can have 64 bit CPU SMP box having many CPUs or even linux
     super-computers. CPU power can be shared by many diskless computer
     users


    Sharing of central server RAM memory by many diskless computer
     users.  For example, if many users are using web browser than at
     server RAM there will be only one copy of web browser in the RAM.
     In case Windows 95 PCs, many users need to have individual copy of
     web browser in local RAM and hence there is wastage of RAM space.


    Diskless computers are extremely fast because program loading time
     is completely eliminated. For example, if the server loads the
     StarOffice suite into memory due to request from one diskless user
     then if another diskless user wants to use the StarOffice suite
     then loading time is avoided since StarOffice is already loaded.


    Diskless linux computers can run programs on multiple servers using
     the "xhost" and DISPLAY environment.


    Very few system administrators required to maitain central server
     unlike Windows 95 PC clients which need many administrators.


    Zero administration at diskless client side. Diskless computers are
     absolutely maintainence free and troublefree.


    Long life of diskless clients - more than 300 years without any
     hardware or software upgrades.


    Eliminates install/upgrade of hardware, software on diskless client
     side.


    Eliminates cost of cdrom, floppy, tape drive, modem, UPS battery,
     Printer parallel ports, serial ports etc..


    Prevents pilferage of hardware components as diskless node has very
     little RAM and low-cost CPU. The server has lots of memory and many
     powerful CPUs.


    Can operate in places like factory floor where a hard disk might be
     too fragile.

  4.  Quick Steps to implement Diskless Nodes

  An overview to build diskless nodes is as follows:

    Download/Install redhat RPM packages from LTSP org
     <http://www.ltsp.org>

    Test with floppy disk (1.44MB) having the PROM program.

    Next you have to make the Network card which has the bootable prom

    Either purchase NIC ready with prom or

    Purchase the eproms

    (or) Purchase Eprom burner to burn your own eproms. Transfer the
     tested program from floppy to prom via eprom burner

    Visit  <http://www.disklessworkstations.com> to buy eprom burners
     and see also ``List of EPROM Burner'' manufacturers, ``Build EEPROM
     burner''

  4.1.  Linux Terminal Server Project - LTSP

  LTSP is an open source code project to build diskless linux computers.

  At LTSP site you will find RPM packages for Redhat Linux and packages
  for Debian Linux which will save you lots of time. The subsequent
  chapters given in this document are for academic purposes only, which
  you can read them if you have more time.

  Visit the LTSP and related sites at :-

    <http://www.ltsp.org>

    <http://www.disklessworkstations.com>

    <http://www.slug.org.au/etherboot> and at mirror-site
     <http://etherboot.sourceforge.net> and at google-site
     <http://www.google.com/search?q=Etherboot>

    <http://metalab.unc.edu/Linux/HOWTO/XFree86-Video-Timings-
     HOWTO.html>

     Related topics worth seeing -

    NCD X-terminal  <http://www.linuxdoc.org/HOWTO/mini/NCD-X-
     Terminal.html>

  5.  Building EEPROM Burner


  5.1.  What is this ?

  (Note: This chapter is written by Abhijit Dasgupta.  Abhijit's email:
  takdoom@yahoo.com

  The name of this project is EEP and it can be obtained from:

    Primary site (download tarball only):
     <http://metalab.unc.edu/pub/Linux/apps/circuits/>

    Browse and/or download:
     <http://homepages.go.com/~abhijit_dasgupta/eep/index.html>

    Browse and/or download:
     <http://members.nbci.com/abhijit_dasgupta/eep/index.html>

     Please do not use the old URL for EEP anymore.)

  EEP is an open hardware design (you are free to copy, use, and modify
  the hardware design) EEPROM burner for 24-pin and 28-pin 5-volt
  EEPROMs.  There are various designs available, but my main goal was to
  have something which

    is easy to build and uses only the most commonly available parts,

    is cheap, and

    is controlled by Linux.

     The latest version is EEP-0.2.

  The ICs in EEP are all common 74HCT series logic chips, and it uses
  the PC parallel port interface.  I wrote the driver code for Linux
  only, but it is GPL code, and it should be easy to modify it for other
  PC operating systems.

  I use EEP to burn netboot PROMs for ethernet cards, which are used to
  make diskless linux boxes.  See the netboot/etherboot packages for
  details of how to do that.  You can also use it for microcontroller
  systems with external ROM (e.g. 8031).

  A photo of the burner is at
  <http://homepages.go.com/~abhijit_dasgupta/eep/eeprom-burner.jpg> and
  a PostScript schematic diagram is at
  <http://homepages.go.com/~abhijit_dasgupta/eep/schematic.ps>.

  5.2.  Supported EEPROMs

  Most 5-volt-programmable 24-pin and 28-pin EEPROMs should work with
  EEP-0.2.  Here is a partial list of common EEPROMS that are known to
  work:

    24-pin 2816/28C16, 2048 bytes (16 kilobits)

    28-pin 2817/28C17, 2048 bytes (16 kilobits)

    28-pin 2864/28C64, 8192 bytes (64 kilobits)

    28-pin 28256/28C256, 32768 bytes (256 kilobits)

     Various vendors manufacture these EEPROMs.  Some are:  Microchip,
     Atmel, Xicor, Catalyst, and STM.

  5.3.  Schematics and pinouts

  The schematic is in PostScript (schematic.ps), but a GIF image
  (schematic.gif) is also included.  The ascii version is older.  In the
  schematic diagram, pin numbers are shown outside each IC diagram.  Pin
  numbers for the big box on the right side are for the 28-pin ZIF
  socket.

  The file pinouts.txt has pinout information for the ICs used.

  For the 74HCT ICs used in the circuit, Vcc and Ground connections are
  not shown in the schematic.  Of course, these pins must be properly
  connected.  Please refer to the pinouts.txt file for full pinouts (in
  particular Vcc/Ground connections).

  5.4.  Construction

  WARNING:  It is easy to destroy the parallel port of your PC by
  connecting things to it.  It is also possible to damage or destroy the
  whole PC, its attachments, peripherals, and people near it by improper
  connections and electrical accidents.  USE EXTREME CAUTION.
  Disclaimer:  Use at your own risk.  There is absolutely no warranty of
  any kind here, see COPYING/LICENSE below.

  The programmer can be built on a breadboard, but use a protoboard for
  a more permanent version.  Use 0.1uF power-bus bypass capacitors
  generously.  The 5V power source can be obtained from the PC itself,
  but be careful here.  The 28-pin ZIF socket is perhaps the most
  expensive component.  If you are building on a breadboard, you may be
  able to get by without it (not recommended).

  The 180 ohms resistor connecting pin 10 (Y6) of the upper 74HCT259 to
  pin 1 of the ZIF socket is a current limiting resistor to protect the
  74HCT259 IC in cases where a 28-pin EEPROM with RDY/BSY pin is used.
  When using 32 kilobytes (256 kilobits) EEPROMs like the 28256, it is
  recommended that this resistor be shorted for more reliable operation.

  5.5.  Jumper setup

  J1 and J2 are single-row 3-pin headers for jumpers.  When using 28-pin
  EEPROMs, jumper the right two pins on both J1 and J2.  For 24-pin
  EEPROMs, jumper the left two pins on both J1 and J2.

  5.6.  Low-justification of 24-pin EEPROM devices

  When plugging in a 24-pin EEPROM device (like 2816) into the 28-pin
  ZIF socket, make sure the 24-pin device is low-justified in the ZIF
  socket.  This means that pins 1, 2, 27, and 28 of the ZIF socket will
  remain unused, and the ground pin of the devices match up (i.e. pin 12
  of the 24-pin device should sit in to pin 14 of the ZIF socket).

  5.7.  Parts List


    ICs:           74HCT123, 74HCT132, 74HCT138, 74HCT157, 74HCT574 (1
     ea), and 2 74HCT259s.

    Resistors:     100K, 10K, 1K, 180 ohms, and 390 ohms (1 ea).

    Capacitors:    100pF, 1uF, (1 ea) and 3 0.1uF power-bus bypass
     capacitors.

    Misc:          1 LED, 1 SPST switch, 25-conductor ribbon cable with
     DB25 male connector, 28 pin ZIF socket (small breadboard can be
     used instead), header pins for jumpering.

  5.8.  If you have already built EEP-0.1

  If you have already built the EEP-0.1 burner, you can make the
  following modificatons to make the EEP-0.2 burner:

  1. remove the connection from 74HCT157 pin 1 (SEL) to the upper
     74HCT259 pin 11 (Y6)

  2. remove the 1K resistor that is connected from pin 1 of ZIF-socket
     to Vcc

  3. add a new connection from pin 1 (SEL) of the 74HCT157 to pin 9 of
     of the DB-25 parallel port

  4. add a new connection from pin 10 of the upper 74HCT259 to the
     unused pin of J1

  5. add a 180 ohms resistor from pin 11 of the upper 74HCT259 to pin 1
     of the ZIF-socket


  5.9.  How to build the software

  Download the software
  <http://metalab.unc.edu/pub/Linux/apps/circuits/EEP-0.2.tar.gz> and
  unpack it.  Then cd to the src directory and type `make'.

  5.10.  Usage

  The progran eep is used for burning and reading an eeprom.  It reads
  data from stdin and writes it to the eeprom. The data needs to be in
  binary (raw) format.  None of the usual hex and/or ascii formats
  (Intel, Motorola srecord, etc) are supported, so if your assembler
  ouputs in only a hex/ascii format, you will need to convert it to
  binary (see, e.g., the Hex2bin and srecord, available from the
  metalab.unc.edu/pub/Linux archive).  When reading, the output is also
  raw binary to stdout (unless the -t option is given).


  ______________________________________________________________________
  Usage:

        eep  -0|-1|-2  -r|-w  -b|-t  offset  size

  where:

      -0|-1|-2  -0 chooses port lp0, -1 port lp1, and -2 port lp2,
      -r|-w     -r reads the eeprom to stdout, and -w burns it from stdin,
      -b|-t     -b is normal (binary) mode, and -t is debugging (ascii hex),
      offset    is the start address within the eeprom, 0..32767, and,
      size      is the number of bytes to read/write, 0..32768.

  The offset and size can be specified as a string of digits in decimal
  notation, but will be taken as hexadecimal when there is a ``0x'' prefix,
  and octal when preceded by ``0''.

  Examples
  --------

  # Read the contents of a 2864 in binary (raw) form and save it in a file
  eep -1 -r -b 0 8192 > contents.bin
  # Same as:
  eep -1 -r -b 0 0x2000 > contents.bin


  # List 16 bytes starting at offset 128
  eep -1 -r -t 128 16
  # Same as:
  eep -1 -r -t 0x80 0x10


  # Write 16384 bytes from the file nepci.lzrom into the first-half of
  # a  28C256 eeprom, through lp0:
  cat nepci.lzrom | eep -0 -w -b 0 16384
  ______________________________________________________________________



  5.11.  Schematic Diagram in ASCII



  ______________________________________________________________________

                         +-------+                      J1
                +5-------|RST    |               +5---o o o----+   +-----------+
                +5--o----|/CLR1  |         10K          |      |   |           |
                    |    |       |-----o--/VVV\-- +5    +------|---|26 A13(+5V)|
        +------+    |    |1/2 123|     |              +--------|-->|27 /WE(NC) |
   16 o-|/CS2  |    |    |       |--||-+              | +------|-->|23 A11(/WE)|
        |   CS1|----o----|B1     | 100pF              | | J2   |   |           |
        |      |         |    /Q1|---------->---------o o o    |   |  ZIF28    |
        |    Y1|---------|/A1    |                        |    |   |  socket   |
        | 138  |         +-------+         _ 1/2 74HCT132 |    |   |   for     |
        |      |                     +5 --| \   __        |    |   |  EEPROM   |
        |    Y2|--------------------------|  O--| \       |    |   |           |
    8 o-|A2    |                +-------+ |_/   |  O-----------|-->|22 /OE     |
    7 o-|A1  Y4|--------------->|EN   Y7|-----o-|_/       |    |   |           |
    6 o-|A0  Y3|----+    +5-----|RST    |     |   180 ohm |    |   |           |
        |    Y0|-+  |           |     Y6|-----|---/VVV\---|----|---|1 A14(NC)  |
        |  /CS3| |  |           | 259 Y5|-----|-----------|----+   |           |
        +------+ |  |           |     Y4|-----|-----------|------->|2 A12(NC)  |
              |  |  |           |     Y3|-----|-----------+        |           |
    5 o--->---|--|--|--------o--|D    Y2|-----|------------------->|21 A10     |
    4 o--->---|--|--|------o-|--|A2   Y1|-----|------------------->|24 A9      |
    3 o--->---|--|--|----o-|-|--|A1   Y0|-----|------------------->|25 A8      |
    2 o--->---|--|--|--o-|-|-|--|A0     |     |                    |           |
              |  |  |  | | | |  +-------+     |      +5------------|28 +5V(NC) |
              |  |  |  | | | |                |                    |           |
              |  |  |  | | | |  +-------+     |                    |           |
              |  |  |  | | | |  |     Y7|-----|------------o------>|3  A7      |
              |  |  +---------->|EN     |-----|-----------o|------>|4  A6      |
              |  |     | | | |  |       |-----|----------o||------>|5  A5      |
              |  |     | | | |  | 259   |-----|---------o|||------>|6  A4      |
              |  |     | | | |  |       |-----|--------o||||------>|7  A3      |
              |  |     | | | |  |       |-----|-------o|||||------>|8  A2      |
              |  |     | | | +--|D      |-----|------o||||||------>|9  A1      |
              |  |     | | +----|A2   Y0|-----|-----o|||||||------>|10 A0      |
              |  |     | +------|A1     |     |     ||||||||       |           |
              |  |     +--------|A0  RST|     |     ||||||||       | ZIF28     |
              |  |              +-------+     |   +------------+   | socket    |
              |  |                    |       |   |   data in  |   |  for      |
              |  |                   +5       +-->|/OE         |   | EEPROM    |
              |  |                                |     574    |   |           |
              |  +------------------------------->|CLK         |   |           |
              +----+                              |   data out |   |           |
                   |                              +------------+   |           |
                   |              +------------+     ||||||||      |           |
    9 o-------------------------->| SEL        |     ||||||||      |           |
                   |              |          B3|<----|||||||o------|19 D7      |
   11 o---<-----------------------|Y3        B2|<----||||||o-------|18 D6      |
   12 o---<-----------------------|Y2        B1|<----|||||o--------|17 D5      |
   13 o---<-----------------------|Y1  157   B0|<----||||o---------|16 D4      |
   15 o---<-----------------------|Y0        A3|<----|||o----------|15 D3      |
                   |              |          A2|<----||o--- data---|13 D2      |
                   |              |          A1|<----|o---- bus ---|12 D1      |
                   |       GND----|/OE       A0|<----o-------------|11 D0      |
    +5--o--+       |              +------------+                   |           |
        |  |  __   o---------------------------------------------->|20 /CE   14|
      100K +-|  \  |  __                                           +---------+-+
    sw1 |    |   O-o-|  \ 1/2 74HCT132                                       |
    o-->o----|__/    |   O---390ohm--+                                       |
    |   |          +-|__/            |                                  GND -+
    |  --- 1uF     |                LED
    |  ---     +5--+                 |
    |   |                            |
    +---o----------------------------o- GND

  Notes:

  1. Pin numbers on the left margin are for DB25 parallel port.
  3. A 24-pin chip (e.g. 2816) must be low-justified in the 28-pin ZIF socket.
  2. Pin numbers in the right box are for the ZIF-28 socket, not the IC.
  7. The signal labels inside the ZIF-28 socket box are for 28-pin EEPROMs
     (they are given in parentheses for 24-pin EEPROMs).
  4. J1 and J2 are single-row 3-pin headers for jumpers (or use a DPDT switch).
  5. For 28-pin EEPROMs, jumper the right two pins of both J1 and J2.
  6. For 24-pin EEPROMs, jumper the left two pins of both J1 and J2.
  8. The SPST switch sw1 needs to be open to enable operation of the programmer.
  9. Please refer to the file pinouts.txt for full pinouts of the ICs used.

  Abhijit Dasgupta
  takdoom@yahoo.com
  ______________________________________________________________________



  6.  EPROM Burners and Memory chips

  Below is the information about EPROM and various types of memory
  chips.

  6.1.  Non-Volatile Memory chips

  Here is the brief descriptions of memory chips and their types.

    PROM: Pronounced prom, an acronym for programmable read-only
     memory. A PROM is a memory chip on which data can be written only
     once. Once a program has been written onto a PROM, it remains there
     forever. Unlike RAM, PROMs retain their contents when the computer
     is turned off.  The difference between a PROM and a ROM (read-only
     memory) is that a PROM is manufactured as blank memory, whereas a
     ROM is programmed during the manufacturing process. To write data
     onto a PROM chip, you need a special device called a PROM
     programmer or PROM burner. The process of programming a PROM is
     sometimes called burning the PROM.  An EPROM (erasable programmable
     read-only memory) is a special type of PROM that can be erased by
     exposing it to ultraviolet light. Once it is erased, it can be
     reprogrammed. An EEPROM is similar to a PROM, but requires only
     electricity to be erased.

    EPROM: Acronym for erasable programmable read-only memory, and
     pronounced e-prom, EPROM is a special type of memory that retains
     its contents until it is exposed to ultraviolet light. The
     ultraviolet light clears its contents, making it possible to
     reprogram the memory. To write to and erase an EPROM, you need a
     special device called a PROM programmer or PROM burner.  An EPROM
     differs from a PROM in that a PROM can be written to only once and
     cannot be erased. EPROMs are used widely in personal computers
     because they enable the manufacturer to change the contents of the
     PROM before the computer is actually shipped. This means that bugs
     can be removed and new versions installed shortly before delivery.

     A note on EPROM technology: The bits of an EPROM are programmed by
     injecting electrons with an elevated voltage into the floating gate
     of a field-effect transistor where a 0 bit is desired. The
     electrons trapped there cause that transistor to conduct, reading
     as 0. To erase the EPROM, the trapped electrons are given enough
     energy to escape the floating gate by bombarding the chip with
     ultraviolet radiation through the quartz window.  To prevent slow
     erasure over a period of years from sunlight and fluorescent
     lights, this quartz window is covered with an opaque label in
     normal use.

    EEPROM: Acronym for electrically erasable programmable read-only
     memory. Pronounced double-e-prom or e-e-prom, an EEPROM is a
     special type of PROM that can be erased by exposing it to an
     electrical charge. Like other types of PROM, EEPROM retains its
     contents even when the power is turned off. Also like other types
     of ROM, EEPROM is not as fast as RAM.  EEPROM is similar to flash
     memory (sometimes called flash EEPROM). The principal difference is
     that EEPROM requires data to be written or erased one byte at a
     time whereas flash memory allows data to be written or erased in
     blocks. This makes flash memory faster.

    FRAM: Short for Ferroelectric Random Access Memory, a type of non-
     volatile memory developed by Ramtron International Corporation.
     FRAM combines the access speed of DRAM and SRAM with the non-
     volatility of ROM. Because of its high speed, it is replacing
     EEPROM in many devices. The term FRAM itself is a trademark of
     Ramtron.

    NVRAM: Abbreviation of Non-Volatile Random Access Memory, a type of
     memory that retains its contents when power is turned off. One type
     of NVRAM is SRAM that is made non-volatile by connecting it to a
     constant power source such as a battery. Another type of NVRAM uses
     EEPROM chips to save its contents when power is turned off. In this
     case, NVRAM is composed of a combination of SRAM and EEPROM chips.

    Bubble Memory: A type of non-volatile memory composed of a thin
     layer of material that can be easily magnetized in only one
     direction. When a magnetic field is applied to circular area of
     this substance that is not magnetized in the same direction, the
     area is reduced to a smaller circle, or bubble.  It was once widely
     believed that bubble memory would become one of the leading memory
     technologies, but these promises have not been fulfilled. Other
     non-volatile memory types, such as EEPROM, are both faster and less
     expensive than bubble memory.

    Flash Memory: A special type of EEPROM that can be erased and
     reprogrammed in blocks instead of one byte at a time. Many modern
     PCs have their BIOS stored on a flash memory chip so that it can
     easily be updated if necessary. Such a BIOS is sometimes called a
     flash BIOS. Flash memory is also popular in modems because it
     enables the modem manufacturer to support new protocols as they
     become standardized.

  6.2.  List of EEPROM Burner manufacturers

  For a list of EPROM burner manufacturers visit the Yahoo site and go
  to economy->company->Hardware->Peripherals->Device programmers.

    Yahoo URL for EPROMs is at
     <http://dir.yahoo.com/Business_and_Economy/Companies/Computers/Hardware/Peripherals/Device_Programmers/>


    Advanced Research Technology B.V <http://www.artbv.nl/ > -
     development, production and sales of electronic programmer
     equipment; development of hardware and software.

    Elnec, Presov <http://www.elnec.com> - manufacturers of
     programmers, emulators and simulators.

    Advin Systems Inc. <http://www.advin.com > - PC-based device
     programmers that support the latest in package types and device
     technologies.

    Andromeda Research Labs <http://www.arlabs.com > - manufactures a
     portable eprom and device programming system.

    B and C Microsystems, Inc <http://www.bcmicro.com/> - offers test
     and duplication/programming equipment for PCMCIA (PC) Cards,
     ISA/PCI Cards, SIMMs, Memory Devices (including FLASH), PLDs.

    BP Microsystems <http://www.bpmicro.com/ > - Device Programmers.

    Bytek <http://www.bytek.com > - designs, develops, manufactures and
     markets micro-processor-based, modular electronic systems used to
     program and test semiconductor devices. Product line includes the
     ChipBurner.

    Concentrated Programming Ltd <http://www.logicaldevices.com/ > -
     offers a full range of device programming solutions.

    Dataman Programmmers Ltd. <http://www.dataman.com/ > - manufacture
     of hand-help EPROM programmer/emulator. Also sell PC-based
     programmers, and Gang-Pro programmers.

    General Device Instruments <http://www.generaldevice.com/ > - IC
     Device programmers. Universal and Gang programmers for Pld, Flash,
     microcontrollers, Proms, EEproms, Memory, Epld, Mach and many other
     ic devices.

    HI-LO System Research Co., Ltd. <http://hilosystems.com.tw > -
     manufacturer of universal and gang device programmers.

    ICE Technology <http://www.icetech.com/ > - EPROM and universal
     device programmers which support memories, microcontrollers, and
     programmable logic devices.

    Iceprom <http://www.inabyte.com/iceprom.html > - in-circuit
     erasable programmable read-only memory.

    Incept Ltd. <http://www.incept.ie >

    International Microsystems Inc <http://www.imtest.com > - High
     speed reliable gang programmer. (PROM, FLASH, Microcontroller,
     PCMCIA memory card).

    JED Microprocessors Pty. Ltd. <http://www.jedmicro.com.au > - plugs
     into a PC printer port D25 connector, and programs any 28-pin or
     32-pin EPROM and FLASH device.

    Logical Devices, Inc <http://www.logicaldevices.com > - device
     programming for PLDs, FPGAs, PROMs, microcontrollers. Producers of
     CUPL compiler for programmable logic and the ALLPRO and Chipmaster
     device programmer.

    MCL Systems <http://www.mcl.dk > - new method not only for
     programming but also for developing your new hardware with
     Integrated Controller Unit. And you don't need to be an expert.

    MQP Electronics <http://www.mqp.com > - manufacturer of universal
     device programmers, gang programmers, production software, and
     package converters. High thoughput and reliability.

    Needham's Electronics <http://www.needhams.com> - manufacturer of
     device programmers.

    NP Programming Services <http://www.npps.com/ > - provides
     programming for memory and logic parts.

    Program Automation, Inc. <http://www.progauto.com > - independent
     service company specializing in high volume PROM programming,
     including flash I/Cs.

    Stag Programmers Inc <http://www.stagusa.com > - manufacturer of
     prom and logic programmers, production handling equipment and UV
     erasers.

    Sunrise Electronics <http://www.sunriseelectronics.com > -
     universal device programmers, gang and in-circuit programmers with
     life time support.

    System General Co. <http://www.sg.com.tw > - Device Programmer,
     EPROM Writer and IC Tester

    Tribal Microsystems <http://www.tribalmicro.com > - universal and
     gang device programmers, 8051 and EPROM emulators, test and burn-in
     sockets and production sockets.

    Universal Device Programmers <http://www.xeltek.com/ >


  7.  Introduction to Network Booting and Etherboot

  This chapter is written by Ken Yap ken.yap@acm.org and explains how to
  bootstrap your computer from a program stored in non-volatile memory
  without accessing your hard disk. It is an ideal technique for
  maintaining and configuring a farm of linux boxes.

  7.1.  What is Network booting?


  Network booting is an old idea. The central idea is that the computer
  has some bootstrap code in non-volatile memory, e.g. a ROM chip, that
  will allow it to contact a server and obtain system files over a
  network link.


  7.2.  How does it work

  In order to boot over the network, the computer must get

  1. an identity

  2. an operating system image and

  3. usually, a working filesystem.

  Consider a diskless computer (DC) that has a network boot ROM. It may
  be one of several identical DCs. How can we distinguish this computer
  from others? There is one piece of information that is unique to that
  computer (actually its network adapter) and that is its Ethernet
  address. Every Ethernet adapter in the world has an unique 48 bit
  Ethernet address because every Ethernet hardware manufacturer has been
  assigned blocks of addresses. By convention these addresses are
  written as hex digits with colons separating each group of two digits,
  for example - 00:60:08:C7:A3:D8 .

  The protocols used for obtaining an IP address, given an Ethernet
  address, are called Boot Protocol (BOOTP) and Dynamic Host
  Configuration Protocol (DHCP). DHCP is an evolution of BOOTP. In our
  discussion, unless otherwise stated, anything that applies to BOOTP
  also applies to DHCP. (Actually it's a small lie that BOOTP and DHCP
  only translate Ethernet addresses. In their foresight, the designers
  made provision for BOOTP and DHCP to work with any kind of hardware
  address. But Ethernet is what most people will be using.)

  An example of a BOOTP exchange goes like this:


  DC: Hello, my hardware address is 00:60:08:C7:A3:D8, please give me my
  IP address.

  BOOTP server: (Looks up address in database.) Your name is aldebaran,
  your IP address is 192.168.1.100, your server is 192.168.1.1, the file
  you are supposed to boot from is /tftpboot/vmlinux.nb (and a few other
  pieces of information).

  You may wonder how the DC found the address of the BOOTP server in the
  first place. The answer is that it didn't. The BOOTP request was
  broadcast on the local network and any BOOTP server that can answer
  the request will.

  After obtaining an IP address, the DC must download an operating
  system image and execute it. Another Internet protocol is used here,
  called Trivial File Transfer Protocol (TFTP). TFTP is like a cut-down
  version of FTP---there is no authentication, and it runs over User
  Datagram Protocol (UDP) instead of Transmission Control Protocol
  (TCP). UDP was chosen instead of TCP for simplicity. The
  implementation of UDP on the DC can be small so the code is easy to
  fit on a ROM. Because UDP is a block oriented, as opposed to a stream
  oriented, protocol, the transfer goes block by block, like this:



       DC: Give me block 1 of /tftpboot/vmlinux.nb.
       TFTP server: Here it is.
       DC: Give me block 2.



  and so on, until the whole file is transferred. Handshaking is a
  simply acknowledge each block scheme, and packet loss is handled by
  retransmit on timeout. When all blocks have been received, the network
  boot ROM hands control to the operating system image at the entry
  point.

  Finally, in order to run an operating system, a root filesystem must
  be provided. The protocol used by Linux and other Unixes is normally
  Network File System (NFS), although other choices are possible. In
  this case the code does not have to reside in the ROM but can be part
  of the operating system we just downloaded. However the operating
  system must be capable of running with a root filesystem that is a
  NFS, instead of a real disk. Linux has the required configuration
  variables to build a version that can do so.



  7.3.  Netbooting in Practice

  Net Loader is a small program that runs as a BIOS extension, usually
  on an EPROM on the NIC. It handles the BOOTP query and TFTP loading
  and then transfers control to the loaded image.  It uses TCP/IP
  protocols but the loaded image doesn't have to be Linux. The loaded
  image can be anything, even DOS.  They can also be loaded from a
  floppy for testing and for temporary setups.

  Besides commercial boot ROMs, there are TWO sources for free packages
  for network booting.  Free implementations of TCP/IP net loaders are -

  1. ETHERBOOT  <http://www.slug.org.au/etherboot/>  and and at mirror-
     site <http://etherboot.sourceforge.net> and at google-site
     <http://www.google.com/search?q=Etherboot>

  2. NETBOOT  <http://www.han.de/~gero/netboot.html>

  Etherboot uses built-in drivers while Netboot uses Packet drivers.
  First you have to ascertain that your network card is supported by
  Etherboot or Netboot. Eventually you have to find a person who is
  willing to put the code on an EPROM (Erasable Programmable Read Only
  Memory) for you but in the beginning you can do network booting from a
  floppy.

  To create a boot floppy, a special boot block is provided in the
  distribution. This small 512 byte program loads the disk blocks
  following it on the floppy into memory and starts execution. Thus to
  make a boot floppy, one has only to concatenate the boot block with
  the Etherboot binary containing the driver for one's network card like
  this:


  ______________________________________________________________________
          # cat floppyload.bin 3c509.lzrom > /dev/fd0
  ______________________________________________________________________



  Get the nfsboot package (the package is available from your favourite
  linux mirror site in the /pub/Linux/system/Linux-boot directory). It
  contains a booteprom image for the network cards (like wd8013) which
  can be directly burned in. See also the LTSP site at
  <http://www.ltsp.org>

  Before you put in the network boot floppy, you have to set up three
  services on Linux -

  1. BOOTP (or DHCP)

  2. TFTP and

  3. NFS.

  You don't have to set up all three at once, you can do them step by
  step, making sure each step works before going on to the next.


  7.3.1.  Bootp

  Install Bootp. See bootp*.rpm on Redhat linux cdrom.  See also LTSP
  site for RPM packages at  <http://www.ltsp.org>.  See also unix manual
  pages 'man 5 bootptab', 'man 8 bootpd', 'man 8 bootpef', 'man 8
  bootptest'.  You then have to ensure that this server is waiting for
  bootp requests.  The daemon can be run either directly by issuing
  command

  ______________________________________________________________________
         bootpd -s
  ______________________________________________________________________



  Or by using inetd edit the file /etc/inetd.conf and put a line like
  this:



  ______________________________________________________________________
          bootps dgram   udp     wait    root    /usr/sbin/in.bootpd    bootpd
  ______________________________________________________________________


  Insert or uncomment the following two lines in /etc/services:

  ______________________________________________________________________
  bootps          67/tcp          # BOOTP server
  tftp            69/udp          # TFTP server
  ______________________________________________________________________



  If you had to modify /etc/inetd.conf, then you need to restart inetd
  by sending the process a HUP signal.

  ______________________________________________________________________
         kill -HUP <process id of inetd>.
  ______________________________________________________________________



  Next, you need to give bootp a database to map Ethernet addresses to
  IP addresses. This database is in /etc/bootptab.  You must modify it
  by inserting the IP addresses of your gateway, dns server, and the
  ethernet address(es) of your diskless machine(s).  It contains lines
  of the following form:


  ______________________________________________________________________
          aldebaran.foo.com:ha=006008C7A3D8:ip=192.168.1.100:bf=/tftpboot/vmlinuz.nb
  ______________________________________________________________________



  Other information can be specified but we will start simple.

  Another example of /etc/bootptab is :


  ______________________________________________________________________
    global.prof:\
            :sm=255.255.255.0:\
            :ds=192.168.1.5:\
            :gw=192.168.1.19:\
            :ht=ethernet:\
            :bf=linux:
    machine1:hd=/export/root/machine1:tc=global.prof:ha=0000c0863d7a:ip=192.168.1.140:
    machine2:hd=/export/root/machine2:tc=global.prof:ha=0800110244e1:ip=192.168.1.141:
    machine3:hd=/export/root/machine3:tc=global.prof:ha=0800110244de:ip=192.168.1.142:
  ______________________________________________________________________



  global.prof is a general template for host entries, where


    sm field contains the subnet mask

    ds field contains the address of the Domain Name Server

    gw field contains the default gateway address

    ht field contains the lan media hardware type

    bf field contains the name of the boot file

  After this, every machine must have a line:


    the first field contains the host name,

    hd field contains the directory of the bootfile,

    the global template can be included with the tc field,

    ha field contains the hardvare address of the ethernet card,

    ip field contains the assigned ip address.

  Now boot the DC with the floppy and it should detect your Ethernet
  card and broadcast a BOOTP request. If all goes well, the server
  should respond to the DC with the information required. Since
  /tftpboot/vmlinux.nb doesn't exist yet, it will fail when it tries to
  load the file.  Now you need to compile a special kernel, one that has
  the option for mounting the root filesystem from NFS turned on. You
  also need to enable the option to get the IP address of the kernel
  from the original BOOTP reply. You also need to compile the Linux
  driver for your network adapter into the kernel instead of loading it
  as a module. It is possible to download an initial ramdisk so that
  module loading works but this is something you can do later.

  You cannot install the zImage resulting from the kernel compilation
  directly. It has to be turned into a tagged image. A tagged image is a
  normal kernel image with a special header that tells the network
  bootloader where the bytes go in memory and at what address to start
  the program. You use a program called mknbi-linux to create this
  tagged image. This utility can be found in the Etherboot distribution.
  After you have generated the image, put it in the /tftpboot directory
  under the name specified in /etc/bootptab. Make sure to make this file
  world readable because the tftp server does not have special
  privileges.


  7.3.2.  Tftp

  For TFTP, see tftp*.rpm on Redhat Linux cdrom.  TFTP (Trivial File
  Transfer Protocol) is a file transfer protocol, such as ftp, but it's
  much simpler to help coding it in EPROMs. TFTP can be used in two
  ways:


    Simple tftp: means that the client can acces to your whole file
     system. It's simpler but it's a big security hole (anyone can get
     your password file via tftp).

    Secure tftp: the tftp server uses a chroot.2 system call to change
     it's own root directory. Anything outside the new root directory
     will be completely inaccessible. Because of the chroot dir becomes
     the new root dir, the hd filed in the bootptab must reflect the new
     situation. For example: when using insecure tftp, the hd field
     contains the full path to the boot directory:
     /export/root/machine1.  When using secure tftp whith /export as
     root dir, then /export becomes / and the hd field must be
     /root/machine1.

  Tftpd is normally started up from inetd with a line like this in
  /etc/inetd.conf.



  ______________________________________________________________________
  tftp dgram udp wait root /usr/sbin/tcpd in.tftpd -s /tftpboot
  #tftp   dgram   udp     wait    root    /usr/sbin/in.tftpd     tftpd /export
  ______________________________________________________________________



  Again, restart inetd with a HUP signal and you can retry the boot and
  this time it should download the kernel image and start it. You will
  find that the boot will continue until the point where it tries to
  mount a root filesystem. At this point you must configure and export
  NFS partitions to proceed.


  7.3.3.  NFS root filesystem

  For various reasons, it's not a good idea to use the root filesystem
  of the server as the root filesystem of the DCs. One is simply that
  there are various configuration files there and the DC will get the
  wrong information that way. Another is security. It's dangerous to
  allow write access (and write access is needed for the root
  filesystem, for various reasons) to your server's root. However the
  good news is that a root filesystem for the DC is not very large, only
  about 30 MB and a lot of this can be shared between multiple DCs.

  Ideally, to construct a root filesystem, you have to know what files
  your operating system distribution is expecting to see there. Critical
  to booting are device files, files in /sbin and /etc. You can bypass a
  lot of the hard work by making a copy of an existing root filesystem
  and modifying some files for the DC. In the Etherboot distribution,
  there is a tutorial and links to a couple of shell scripts that will
  create such a DC root filesystem from an existing server root
  filesystem. There are also troubleshooting tips in the Etherboot
  documentation as this is often the trickiest part of the setup.

  The customised Linux kernel for the DC expects to see the root
  filesystem at /tftpboot/(IP address of the DC), for example:
  /tftpboot/192.168.1.100 in the case above. This can be changed when
  configuring the kernel, if desired.

  Now create or edit /etc/exports (see 'man 5 exports' and 'man 8
  exportfs') on the server and put in a line of the following form:


  ______________________________________________________________________
  /tftpboot/192.168.1.100 aldebaran.foo.com(rw,no_root_squash)
  ______________________________________________________________________



  The rw access is needed for various system services. The
  no_root_squash attribute prevents the NFS system from mapping root's
  ID to another one. If this is not specified, then various daemons and
  loggers will be unhappy.

  Start or restart the NFS services (rpc.portmap and rpc.mountd) and
  retry the diskless boot.  If you are successful, the kernel should be
  able to mount a root filesystem and boot all the way to a login
  prompt. Most likely, you will find several things misconfigured. Most
  Linux distributions are oriented towards disked operation and require
  a little modification to suit diskless booting. The most common
  failing is reliance on files under /usr during the boot process, which
  is normally imported from a server late in the boot process. Two
  possible solutions are -


  1. Provide the few required files under a small /usr directory on the
     root filesystem, which will then be overlaid when /usr is imported,
     and


  2. Modify the paths to look for the files in the root filesystem. The
     files to edit are under /tftpboot/192.168.1.100 (remember, this is
     the root directory of the DC).

  You may wish to mount other directories from the server, such as /usr
  (which can be exported read-only).


  7.3.4.  Burn EPROM

  When you are satisfied that you can boot over the network without any
  problems, you may wish to put the code on an EPROM.


  7.4.  Uses of Network booting

  X-terminals are one natural use of network booting. The lack of a disk
  in the terminal makes it quieter and contributes to a pleasant working
  environment. The machine should ideally have 16MB of memory or more
  and the best video card you can find for it. This is an ideal use for
  a high-end 486 or low-end Pentium that has been obsoleted by hardware
  advances.  Other people have used network booting for clusters of
  machines where the usage is light on the DC and does not warrant a
  disk, e.g. a cluster of classroom machines.

  7.5.  For more information

  Your first stop should be the Etherboot home page:
  <http://www.slug.org.au/etherboot/> and at mirror-site
  <http://etherboot.sourceforge.net> and at google-site
  <http://www.google.com/search?q=Etherboot>

  There you will find links to other resources, including a mailing list
  you can subscribe to, where problems and solutions are discussed.

  Related documents


    NFS-root Mini Howto at /usr/doc/HOWTO/mini or on Linux cdrom.

    Linux Networking-HOWTO by Terry Dawson,  at /usr/doc/HOWTO or on
     linux cdrom 94004531@postoffice.csu.edu.au

    NET-3-Howto at /usr/doc/HOWTO or on Linux cdrom.

    /usr/src/linux/README about configuring and compiling new kernels

  8.  Redhat Linux configuration

  The DC requests to mount /tftpboot/< IP address of DC > (in Linux
  Kernel 2.1 and above it is - /tftpboot/< name of DC in bootptab > ) as
  its root directory '/' by NFS from server. You must export this from
  the server (rw, no_root_squash) because the DC wants to write on it
  (log files, etc).

  The root directory / must contain /sbin, /bin, /lib, /etc, /var, /tmp,
  /root, /dev and /proc.

  /sbin, /bin, /lib can be a copy of an existing Redhat Linux system.
  They can be shared between all DCs. But hard links only. By the way,
  don't link to server originals.
  /etc, /var and /dev should be non-sharable copies. Customise
  /etc/sysconfig/network, /etc/sysconfig/network-scripts/ifcfg-eth0,
  /etc/fstab, /etc/conf.modules, and others. Turn off all network
  services you don't need. Remove all stuff you don't need from /var,
  e.g. RPM db, lpd files.

  /root and /proc should just exist. /tmp should exist and be mode 1777.

  You probably want to create /usr and /home mount points. /usr can be
  mounted ro (read-only).

  About 10 MB per DC plus about 15 MB of shared files should be
  sufficient. By the way, if your DCs are quite similar, the kernel
  image can also be shared.

  Here is an illustrative script to create the first root filesystem.

  ______________________________________________________________________
  #!/bin/sh
  if [ $# != 1 ]
  then
          echo Usage: $0 client-IP-addr
          exit 1
  fi

  cd /

  umask 022

  mkdir -p /tftpboot/$1

  # just make these ones
  for d in home mnt proc tmp usr
  do
          mkdir /tftpboot/$1/$d
          done

          chmod 1777 /tftpboot/$1/tmp

          touch /tftpboot/$1/fastboot
          chattr +i /tftpboot/$1/fastboot

          # copy these ones
          cp -a bin lib sbin dev etc root var /tftpboot/$1

  cat <<EOF
  Now, in /tftpboot/$1/etc, edit

                  sysconfig/network
                  sysconfig/network-scripts/ifcfg-eth0
                  fstab
                  conf.modules

  and configure

                  rc.d/rc3.d
  EOF
  ______________________________________________________________________



  Here is an illustrative script to duplicate the root filesystem



  ______________________________________________________________________
  #!/bin/sh
  if [ $# != 2 ]
  then
          echo Usage: $0 olddir newdir
          exit 1
  fi

  cd /tftpboot

  if [ ! -d $1 ]
  then
          echo $1 is not a directory
          exit 1
  fi

  umask 022

  mkdir -p $2

  # just make these ones
  for d in home mnt proc tmp usr
  do
          mkdir $2/$d
  done

  chmod 1777 $2/tmp

  touch $2/fastboot
  chattr +i $2/fastboot

  # link these ones
  for d in bin lib sbin
  do
          (cd $1; find $d -print | cpio -pl ../$2)
  done

  # copy these ones
  for d in dev etc root var
  do
          cp -a $1/$d $2
  done

  cat <<EOF
  Now, in /tftpboot/$2/etc, edit

          sysconfig/network
          sysconfig/network-scripts/ifcfg-eth0
          fstab (maybe)
          conf.modules (maybe)

  and configure

          rc.d/rc3.d
  EOF
  ______________________________________________________________________



  8.1.  X-terminal

  On the server, make sure the DC is matched by a clause in
  /etc/X11/xdm/Xaccess and comment out the :0 in /etc/X11/xdm/Xservers.
  Then make sure that xdm is run from the init scripts.


  On the client, run X -query server

  You will get the xdm login box and then all your X clients will run on
  the server.

  For other applications use - you could use diskless technique for
  netboot routers, print servers (but should not be spooling print
  server), standalone apps, etc.

  9.  LanWorks BootWare PROMs

  This information may save you time.  In order to make LanWorks
  BootWare(tm) PROMs to correctly start up a Linux kernel image, the
  "bootsector" part of the image must be modified so as to enable the
  boot prom to jump right into the image start address.  The net-
  bootable image format created by netboot/etherboot's `mknbi-linux'
  tool differs and will not run if used with BootWare PROMs.

  A modified bootsector together with a Makefile to create a BootWare-
  bootable image after kernel compilation can be found at -

    Bwimage package
     <ftp://ftp.ipp.mpg.de/pub/ipp/wls/linux/bwimage-0.1.tgz>

    See also  <http://www.patoche.org/LTT/net/00000096.html>

    LanWorks BootWare Boot ROMs  <http://www.3com.com/lanworks>

  Refer to the README file for installation details. Currently, only
  "zImage"-type kernels are supported. Unfortunately, kernel parameters
  are ignored.

  This section courtesy of Jochen Kmietsch email to -
  jochen.kmietsch@tu-clausthal.de for any questions.

  10.  Etherboot

  Etherboot is a package for creating ROM images that can download code
  over the network to be executed on an x86 computer. Typically the
  computer is diskless and the code is Linux, but these are not the only
  possibilities.

  This document is at the Etherboot Home Page
  <http://www.slug.org.au/etherboot/> and at mirror-site
  <http://etherboot.sourceforge.net> and at google-site
  <http://www.google.com/search?q=Etherboot> This document explains how
  to install, configure and use the Etherboot package.

  11.  Netboot

  Netboot was written by Zurck zu Gero. The main site is at
  <http://www.han.de/~gero/netboot.html>.

  11.1.  Introduction

  The following list shows just a few examples of what Netboot can be
  used for:


    Printer spooler

    Terminal server

    X11 terminal


    Data logging system

    Network-Computer (NC)

    Some more ....

  For the bootrom to find the kernel image it uses the BOOTP protocol as
  defined in ``'' and ``'' to get the necessary boot information, and
  then loads the actual image using the TFTP protocol as defined in
  ``''.

  The exact specifications for this netboot process can be found
  <http://www.han.de/~gero/netboot/english/spec.html>.


  11.2.  Mailing list

  There exists a mailing list devoted to network booting. To subscribe
  simply send a mail with the line

  subscribe netboot

  in it's body to majordomo@baghira.han.de

  The subject in the mail header doesn't matter.  After subscribing to
  it, you can send messages into the list by writing a mail to
  netboot@baghira.han.de.

  11.3.  Netboot useful links

  Netboot mailing list archive is at
  <http://www.han.de/~gero/netboot/archive/maillist.html>


    3com drivers at  <http://support.3com.com/infodeli/tools/nic>

    Accton drivers at here
     <http://www.accton.com/accton/drivers/adapter.html>

    Artisoft <http://www.artisoft.com>

    CNET <http://www.cnet.com.tw>

    Compaq <http://www.compaq.com/support/networking>

    D-Link <http://www.dlink.com>

    Microdyne <http://www.mcdy.com/marketin/prodman/prodcat.htm>

    Many NE2000 PCI cards are based on Realtek chipsets. Get drivers
     here <http://www.realtek.com.tw/cn/driver/driver.htm>

    Standard Microsystems Corp <http://www.smc.com/support.html>

    Surecom <http://www.sure-com.net>

    Thomas Conrad corp
     <http://www.compaq.com/support/networking/OutOfProduction.html>

    Winbond <http://www.winbond.com.tw>

    Xircom <http://www.xircom.com>



    Webopaedia page <http://www.sandybay.com/pc-
     web/network_interface_card_NIC.htm> on network cards

    Jargon's driver page
     <http://www.evitech.fi/~jarnomn/files/drivers/net_d.html> with many
     drivers for older network cards.

    Etherboot <http://www.slug.org.au/etherboot/> and at mirror-site
     <http://etherboot.sourceforge.net> and at google-site
     <http://www.google.com/search?q=Etherboot> This is a project
     similar to Netbot but based on the BSD bootrom code.

    How to make an X Window Terminal
     <http://www.menet.umn.edu/~kaszeta/unix/xterminal/index.html> out
     of your old or outdated PC.

    List of jumper settings <http://www.slug.org.au/NIC/index.html> for
     various network cards. This page also contains many other good
     links.

    Freefire <http://sites.inka.de/lina/freefire-l/tools.html> is the
     home page of the Freefire project, which lists many resources for
     network security issues.

  12.  Related URLs


    See 'Diskless-root-NFS-HOWTO' at
     <http://metalab.unc.edu/LDP/HOWTO/Diskless-root-NFS-HOWTO.html>

    Linux goodies  <http://www.aldev.8m.com> and mirrors at webjump
     <http://aldev.webjump.com>, angelfire
     <http://www.angelfire.com/nv/aldev>, geocities
     <http://www.geocities.com/alavoor/index.html>, virtualave
     <http://aldev.virtualave.net>, bizland <http://aldev.bizland.com>,
     theglobe <http://members.theglobe.com/aldev/index.html>, spree
     <http://members.spree.com/technology/aldev>, infoseek
     <http://homepages.infoseek.com/~aldev1/index.html>, bcity
     <http://www3.bcity.com/aldev>, 50megs <http://aldev.50megs.com>

  13.  Copyright Notice

  Copyright policy is GNU/GPL as per LDP (Linux Documentation project).
  LDP is a GNU/GPL project.  Additional restrictions are - you must
  retain the author's name, email address and this copyright notice on
  all the copies. If you make any changes or additions to this document
  than you should intimate all the authors of this document.

  14.  Other Formats of this Document

  This document is published in 11 different formats namely - DVI,
  Postscript, Latex, Adobe Acrobat PDF, LyX, GNU-info, HTML, RTF(Rich
  Text Format), Plain-text, Unix man pages and SGML.

    You can get this HOWTO document as a single file tar ball in HTML,
     DVI, Postscript or SGML formats from -
     <ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/other-formats/> and
     <http://www.linuxdoc.org/docs.html#howto>

    Plain text format is in:
     <ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO> and
     <http://www.linuxdoc.org/docs.html#howto>

    Single HTML file format is in:
     <http://www.linuxdoc.org/docs.html#howto>

    Translations to other languages like French, German, Spanish,
     Chinese, Japanese are in
     <ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO> and
     <http://www.linuxdoc.org/docs.html#howto> Any help from you to
     translate to other languages is welcome.

     The document is written using a tool called "SGML-Tools" which can
     be got from - <http://www.sgmltools.org> Compiling the source you
     will get the following commands like

    sgml2html CVS-HOWTO.sgml     (to generate html file)

    sgml2rtf  CVS-HOWTO.sgml     (to generate RTF file)

    sgml2latex CVS-HOWTO.sgml    (to generate latex file)

  LaTeX documents may be converted into PDF files simply by producing a
  Postscript output using sgml2latex ( and dvips) and running the output
  through the Acrobat distill ( <http://www.adobe.com>) command as
  follows:

  ______________________________________________________________________
  bash$ man sgml2latex
  bash$ sgml2latex filename.sgml
  bash$ man dvips
  bash$ dvips -o filename.ps filename.dvi
  bash$ distill filename.ps
  bash$ man ghostscript
  bash$ man ps2pdf
  bash$ ps2pdf input.ps output.pdf
  bash$ acroread output.pdf &
  ______________________________________________________________________


  Or you can use Ghostscript command ps2pdf.  ps2pdf is a work-alike for
  nearly all the functionality of Adobe's Acrobat Distiller product: it
  converts PostScript files to Portable Document Format (PDF) files.
  ps2pdf is implemented as a very small command script (batch file) that
  invokes Ghostscript, selecting a special "output device" called
  pdfwrite. In order to use ps2pdf, the pdfwrite device must be included
  in the makefile when Ghostscript was compiled; see the documentation
  on building Ghostscript for details.

  This howto document is located at -

    <http://sunsite.unc.edu/LDP/HOWTO/CVS-HOWTO.html>

  Also you can find this document at the following mirrors sites -

    <http://www.caldera.com/LDP/HOWTO/CVS-HOWTO.html>

    <http://www.WGS.com/LDP/HOWTO/CVS-HOWTO.html>

    <http://www.cc.gatech.edu/linux/LDP/HOWTO/CVS-HOWTO.html>

    <http://www.redhat.com/linux-info/ldp/HOWTO/CVS-HOWTO.html>

    Other mirror sites near you (network-address-wise) can be found at
     <http://sunsite.unc.edu/LDP/hmirrors.html> select a site and go to
     directory /LDP/HOWTO/CVS-HOWTO.html


  In order to view the document in dvi format, use the xdvi program. The
  xdvi program is located in tetex-xdvi*.rpm package in Redhat Linux
  which can be located through ControlPanel | Applications | Publishing
  | TeX menu buttons.  To read dvi document give the command -
               xdvi -geometry 80x90 howto.dvi
               man xdvi



  And resize the window with mouse.  To navigate use Arrow keys, Page
  Up, Page Down keys, also you can use 'f', 'd', 'u', 'c', 'l', 'r',
  'p', 'n' letter keys to move up, down, center, next page, previous
  page etc.  To turn off expert menu press 'x'.

  You can read postscript file using the program 'gv' (ghostview) or The
  ghostscript program is in ghostscript*.rpm package and gv program is
  in gv*.rpm package in Redhat Linux which can be located through
  ControlPanel | Applications | Graphics menu buttons. The gv program is
  much more user friendly than ghostscript.  Also ghostscript and gv are
  available on other platforms like OS/2, Windows 95 and NT, you view
  this document even on those platforms.


    Get ghostscript for Windows 95, OS/2, and for all OSes from
     <http://www.cs.wisc.edu/~ghost>

  To read postscript document give the command -


                       gv howto.ps
                       ghostscript howto.ps



  You can read HTML format document using Netscape Navigator, Microsoft
  Internet explorer, Redhat Baron Web browser or any of the 10 other web
  browsers.

  You can read the latex, LyX output using LyX a X-Windows front end to
  latex.

  15.  Topics for Academics and Universities

  This section is for academic interest only - for universities or
  research institutes.  If you have plenty of time then you can read it.
  These links are to RFCs and to the history of diskless nodes.
  Students will find these links interesting to read the history of
  development of diskless workstations.

  Word of Caution:  The information and data given by these URLs may be
  old.


    Install Instructions at  <http://www.aldev.8m.com/disklesshowto-
     install.html> Mirror :  <http://aldev.webjump.com/disklesshowto-
     install.html>


    Troubleshoot Problems <http://www.aldev.8m.com/disklesshowto-
     RFC-951.html> Mirror :  <http://aldev.webjump.com/disklesshowto-
     RFC-951.html>


    RFC 951 <http://www.aldev.8m.com/disklesshowto-RFC-1350.html>
     Mirror :  <http://aldev.webjump.com/disklesshowto-RFC-1350.html>



    RFC 1533 <http://www.aldev.8m.com/disklesshowto-RFC-1533.html>
     Mirror :  <http://aldev.webjump.com/disklesshowto-RFC-1533.html>


    RFC 1350 <http://www.aldev.8m.com/disklesshowto-Troubleshoot.html>
     Mirror :  <http://aldev.webjump.com/disklesshowto-
     Troubleshoot.html>



