Network Booting a Linux STB with PXE

Summary
PXE (Preboot eXecution Environment) is, in one persons words, Intel's attempt at making PCs work more like SUNs (
ref
). PXE
outlines a protocol for enabling the BIOS to retrieve the operating system over standard network protocols.
This document outlines the process of setting up an Allwell STB to use a PXE enabled BIOS to load and run a Linux kernel
and root file system
Contents
Introduction and Prerequisites
Conceptual Overview
Setting Up DHCP
Installing the TFTPD server
Moving Kernel and Root FS Images
Setting Up PXELINUX
Configuring the Client
Links
Introduction and Prerequisites
This
document steps through the process of setting up the appropriate
servers, creating the client code, and enabling the client to boot. It
is assumed that the reader has a fundamental grasp of networking
concepts. DHCP, Linux Kernel, TFTP, and BIOS concepts will be covered
here, as well, and some knowledge of those topics is required.
Also,
you'll need a kernel and root file system setup. I think the easiest
way to do all of that is to follow the instructions in the Bootdisk
HOWTO (part of the standard LDP HOWTO documents) as if you were making
a two-disk floppy bootdisk set. I have been told that some
distributions (Slackware?) come with boot/root images. I have also
heard that there is a set on the FTP site at kernel.org. That may be a
faster way to the goal then the Bootdisk HOWTO.
The
client used in this case was a GCT-Allwell 3036 with the PXE BIOS
extension. The servers were just clunky old PCs with Trustix or
Mandrake loaded on them.
Conceptual Overview
In the case presented in this document, PXE works like this:

The client is booted.
The BIOS portion of the client (or the Network Card
firmware) makes a DHCP request.
The DHCP server responds with the usual information (IP, netmask, gateway, etc.), but in addition
provides information about the location of a TFTP server.
When the client receives the informatio