The following are some of the resources that I've come across in my attempts to use Linux as an embedded system.

• General embedded systems information:
  • Introduction to Real Time -- an article by David Stewart discussing the characteristics of real-time systems
  • LinuxDevices.com -- a community of designers that use Linux as an embedded operating system
  • "Selecting the right RTOS, a Comparative Study, part 1 & 2" -- an article by by Michael Anderson for the Embedded Systems Conference (Note that you will need to register before you can download this article.)
  • PC chipsets build a firm foundation for embedded applications -- a good summary by Scott Rosenthal, an engineer with SLTF Consulting, of some of the things that can be done in this lab
• Linux Help Resources:
  • Linux.org -- click on the link to documentation to access HOWTOs, Project Guides, FAQs, and Linux Man Pages (download via FTP)
• Small Linux Distributions:
  • Pocket Linux
  • BasicLinux
  • Linux Router
• Single Board Computers (SBCs):
  • Technologic Systems, Inc.
  • JK Microsystems, Inc.
  • Mini-ITX Motherboards
  • iBox Slim PC (uses the SBC above in a nice little box)
• Documentation on the Linux boot process:
  • The Linux Bootdisk HOWTO
  • The CTDP Linux Startup Manual
  • Linux From Scratch
  • Starting your Software Automatically on Boot
• General I/O Theory for Linux:
  • Linux I/O Port Programming mini-HOWTO
  • Serial Port HOWTO
• Devices:
  • Intelligent Motion Systems, Inc. motors, drives, and controls
  • IntelLiDrives, Inc. linear stepper motors
  • EmbeddedEthernet.com can add 10BaseT to any application
  • Matrix Orbital Serial Interface Displays
  • Parallax, Inc.'s Motor Control Devices
• Some interesting applications:
  • Building a Linux/RTAI based software radio
  • Converting an Embedded DOS SONAR System to Linux