Chapter 7. The Embedded Linux Workshop

THIS CHAPTER DESCRIBES THE EMBEDDED LINUX WORKSHOP (ELW), an Open Source embedded Linux toolkit—put together specifically for this book—that makes it easy to build embedded Linux applications quickly and efficiently. As discussed in Chapter 6,“Embedded Linux Toolkits,” there are already several embedded Linux toolkits available—so why would I bother to create another one? The reason is simple: I wanted to create an Open Source embedded Linux teaching aid that’s well documented and simple enough to understand quickly and completely, yet powerful enough for any embedded Linux project.

Here’s some basic info you need to know about using ELW:

• ELW assumes that you’re using a standard PC with a BIOS to prototype your embedded application.

• ELW uses the SYSLINUX boot loader to load the kernel and root filesystem.

• ELW doesn’t get into the gory details of how the processor initializes the hardware, loads the kernel and root filesystems into memory, switches the processor to 32-bit mode, and starts the kernel.These details vary wildly from processor to processor; covering them all in a single book would be impossible.The whole topic is glossed over with this simple statement:“The BIOS and SYSLINUX do that.” For more information, see Chapter 4,“Booting Your Embedded Linux Device.”

Of course, in your embedded Linux project, you may not have a BIOS and SYSLINUX may not be appropriate—after all, it only works on an x86 platform. For that reason, I won’t spend a lot of time on SYSLINUX, but it’s a great utility that performs a specific need very well.You may even want to take a look at it when you’re emulating its behavior for your own embedded design.