Edit syslinux.cfg and change the LEAFCFG variable to point to your floppy device (so you can easily add or remove packages to load without buring a new ISO-image:

display syslinux.dpy
timeout 0
default linux initrd=initrd.lrp init=/linuxrc rw root=/dev/ram0 LEAFCFG=/dev/fd0:msdos

This will be your bootable the floppy for the CD creation.

The floppy device will be used to store your configuration settings.

Edit leaf.cfg on a blank formatted floppy disk, add your packages to LRP and change PKGPATH to point to your CDROM and the floppy device.

LRP="root config etc local modules iptables dnsmasq keyboard shorwall ulogd libz mawk libssl libm ezipupd dropbear webconf ppp pppoe libpcap"
PKGPATH=/dev/fd0:msdos,/dev/cdrom:iso9660
syst_size=8M
log_size=2M

You can save your configuration changes onto the floppy, you have declared leaf.cfg

To configure the DHCP server you need to find out the MAC address of the interface on which the PXE boot will take place. In most cases the MAC address is shown when the PXE client in the BIOS starts.

See the system specific sections on Soekris and LexSystem how to find out the right MAC address on your system.

When you have the address, edit the file /etc/dhcpd.conf:

#
subnet 192.168.1.0 netmask 255.255.255.0 {

    default-lease-time 600;
    max-lease-time 7200;

    host pxe {
        hardware ethernet  00:00:c3:2f:63:80;
        fixed-address 192.168.1.254;
        option host-name "pxe";
        filename "pxelinux.0";
    }
}

Restart the dhcp daemon.

Unzip and untar the pxeinstall.tgz file in the root directory of the TFTP server. On my system this is /tftpboot.

The directory /tftpboot/pxelinux.cfg contains three files: default, lexsystem and net4501. The file default is the one being used by the PXE boot functionality and is right after unzipping and untarring a copy of the lexsystem file.

This file has pretty much the same layout as any other syslinux.cfg file and defines where the kernel and the initial file system image can be found. Like any other LEAF distribution it also contains the packages to be installed. In this specific case the packages will be downloaded with TFTP prior to installation.

Depending on the system that you want to boot via PXE you should copy either the lexsystem file or the net4501 file to default. The lexsystem file can be used for systems with a keyboard and video card. The net4501 file should be used for systems with only a serial console.

Now that the needed servers are configured it is time to go to your specific system. In the following sections, the PXE boot sequence for the Soekris system is described, the one for LexSystem is similar.

Connect a terminal to the serial port and fire-up your Soekris system. You should see something like this:

OS ver. 1.10  20020603  Copyright (C) 2000-2002 Soekris Engineering.

Soekris Engineering net4501               CPU 80486 134 Mhz 

0064 Mbyte Memory

PXE-M00: BootManage UNDI, PXE-2.0 (build 082)

Slot   Vend Dev  ClassRev Cmd  Stat CL LT HT  Base1    Base2   Int 
-------------------------------------------------------------------
0:00:0 1022 3000 06000000 0006 2280 00 00 00 00000000 00000000 00
0:18:0 100B 0020 02000000 0107 0290 00 3F 00 0000E001 A0000000 10
0:19:0 100B 0020 02000000 0107 0290 00 3F 00 0000E101 A0001000 11
0:20:0 100B 0020 02000000 0107 0290 00 3F 00 0000E201 A0002000 05

 5 Seconds to automatic boot.   Press Ctrl-P for entering Monitor.

Now press <Ctrl-P> and give the command boot f0.

comBIOS Monitor.   Press ? for help.

> boot F0

BootManage UNDI, PXE-2.0 (build 082)
BootManage PXE-2.0 PROM 1.0, NATSEC 1.0, SDK 3.0/082 (OEM52)
Copyright (C) 1989,2000 bootix Technology GmbH, D-41466 Neuss.
PXE Software Copyright (C) 1997, 1998, 1999, 2000 Intel Corporation.
Licensed to National Semiconductor

CLIENT MAC ADDR: 00 00 C3 2F 63 80

Here you have the MAC address that you need to configure your DHCP server. If your DHCP and TFTP server were correctly setup and are connected to the right interface of the Soekris, the boot sequence should continue with:

DHCP /

CLIENT IP: 192.168.1.254  MASK: 255.255.255.0  DHCP IP: 192.168.1.200

TFTP /

PXELINUX 1.76 2002-08-27  Copyright (C) 1994-2002 H. Peter Anvin

Linux version 2.4.18 ..............
..
<snip> Linux kernel loading
..
Kernel command line: console=ttyS0,19200 BOOT_IMAGE=pxe/linux ip=192.168.1.254:::255.255.255.0:pxe:eth0 rw initrd=pxe/initrd.lrp init=/linuxrc root=/dev/ram0 boot=/tftp/192.168.1.200 LRP=etc,inittabc,hdsupp,wget,smbmount 
..
eth0: link up.
IP-Config: Complete:
      device=eth0, addr=192.168.1.254, mask=255.255.255.0, gw=255.255.255.255,
     host=pxe, domain=, nis-domain=(none),
     bootserver=255.255.255.255, rootserver=255.255.255.255, rootpath=
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
..
<snip> kernel loading continues
..

As you see, during kernel loading the ip configuration is set based upon the parameters passed on the kernel command line.

The whole sequence should end with a login prompt. You what to do next ;-)

The LexSystem we have tested is based on the so-called CV860A board with a VIA C3 533A processor. The board supports up to 512MB PC133 SDRAM and is delivered with two or optional three network interfaces (usually Realtek with rtl8139too driver). Mass storage devices supported are IDE HD, CF and DOM.

It is a good idea to have LAN as third boot device in the "Advanced BIOS Features". The network interfaces can be configured by pressing <Shift-F10> to enter the NIC BIOS setup. The options that must be set here are:

One of the problems of the LexSystem is, that you do can not recognize which NIC you are configuring as it is not really shown if you don't have all 3 messages enabled (3 NIC boot agent configuration roms out there). Also the order in the BIOS is not the order of the interfaces set by the linux kernel...

We had to provide an separate configuration file, because the board behaves somewhat wierd during setup/installation with pxeinstall. During pxe part of booting it uses eth0 and after getting a dhcp address and changing to TFTP to load kernel, basic cfg and basic applications it uses eth1. Additionally it is important that eth0 and eth1 connect the same LAN segment during install, because DHCP server and TFTP server has to be accessible on the same IP address.