Linux Appliance Design: A Hands-On Guide to Building Linux Appliances

Toasters, ovens, and dishwashers are a few of the appliances found in our everyday lives. Though we are quite familiar with their use, few of us stop to think about how an appliance works under the hood, or even what makes an appliance, well, an appliance. This book defines an appliance as a device designed to primarily perform a single function. If you think about the appliances just mentioned, you’ll see that this definition holds true— toasters toast, ovens bake, and dishwashers wash dishes. Compared to a PC, which is capable of performing thousands of diverse functions depending on the hardware and software installed, traditional appliances are boring and simple.

What does this have to do with Linux? For starters, traditional appliances are no longer so simple. What used to be electrified but still mechanical devices, such as a vacuum cleaners, are now not only electronic, but include processors, circuit boards, and sophisticated user interfaces. With these changes comes the need to run an operating system on the appliance to manage the new features. Linux is a natural fit for this because it is low cost (in most cases, it is free to use) and open source (which means you can modify it to better suit your needs). However, the real place where Linux fits in is with the new types of appliances that are being designed. Digital video recorders (DVRs) were unheard of just a few years ago, but the first and most popular DVR appliance, the TiVo, runs on Linux, as do many other home networking and entertainment appliances.

If you were to build the next great robotic house-cleaning system, you’d want to avoid designing it completely from scratch. You’d reuse as many parts as possible from your earlier robots, and you’d use off-the-shelf components wherever possible. The same reuse mentality applies to Linux appliances, and that’s where this book can help.