Introduction

Prior and Related Work

Hardware / Software

Embeded Xinu Video #1

Embeded Xinu Video #2

Project pictures

Hardware

As our target platform, we have chosen the ubiquitous Linksys WRT54GL family of wireless routers. These routers devices are readily available at inexpensive prices, and can already be found in homes, small businesses, and collegedorm rooms. They contain a little-endian embedded MIPS 32 processor, operating in the 200-300 MHz range, with 16MB of RAM, and 4MB FlashROM. Several versions of the router are available, but all have easily accessible serial port connections on the main board that allow direct access to the device rmware.

 

The modications made to the platform are non-destructive, and the WRT54GL once again becomes a fully-functional wireless router running its stock system upon reboot. TheEmbedded Xinu site [2] provides parts lists, diagrams, directions and pictures for making the simple serial modications required.

This embedded platform can be used in a stand-alone con- guration in which a single student computer with a network card and a serial port manages a dedicated WRT54GL
router. The advantage of this conguration is simplicity, and it can be realized in both a laboratory setting, or in many cases at home and in dorm rooms. Students in the initial offering of UB's CSE 321 course (described below) followed this route, with many students choosing to purchase their own routers for use in the course. The cost of the hardware, with modications, is less than a typical textbook, and the platform can be used later for either continued embedded system exploration, or for its original purpose as a home networking applicance. (Or both, with sucient eort.) As shown in Figure 1, the platform can also be used in a dedicated pool conguration, where a collection of routers are made available for \checkout" on the network, and students can remotely power, upload, and interact with their embedded operating system kernels from any front-end machine on the network with appropriate connection tools. In the pool conguration, students can make use of the platform without requiring dedicated lab space, and the pool can be used by several dierent courses simultaneously. The next section describes the software infrastructure we have built to support the pool conguration at MU..

<<Previous Next>>