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EMBEDDED NETWORK APPLINCES WITH LINUX

by Greg Ungerer

Start ý A Closer Look ý Why Linux? ý The Building Process ý Microcontroller Linux ý Porting the Application Set ý Debugging ý Future Looks Bright ý Sources and PDF

The Linux operating system and GNU application set is a popular choice for building powerful, reliable network servers. Given this strong network background, Linux and GNU make a perfect platform for building small, low-cost embedded network appliances. Linux is typically used on interactive, general-purpose workstations and large servers. There are a number of unique challenges involved in getting Linux and the GNU application set operating happily in embedded hardware (i.e., hardware that has only minimal resources).

In this article, I will discuss the advantages of using Linux in small network devices. One example system will be presented in some detail. The key points of the construction process will be examined, and the overall techniques and decision justifications will be provided to show the power of extending Linux into small environments.

The world is full of embedded computing devices. They are used to control all sorts of everyday things, from automobile engines to home video recorders. Traditionally, these types of embedded devices have existed in isolation. They are standalone computing devices that silently do their programmed tasks. More and more of these objects are being connected to networks, and even the Internet. They are actively communicating with each other and the world at large. It is truly becoming a connected world.

This trend has pushed both hardware and software technology in a direction that allows for building low-cost embedded platforms that are networked. These thin servers are perfect for embedding in intelligent devices, devices that are information-aware appliances. They not only perform their own specific control functions but can also interact over a network to allow a whole new set of distributed features.

Embedded devices connected to a network, particularly the Internet, take on a whole new range of responsibilities. They now need to be capable of talking standard protocols, like TCP/IP and its associated application set. They also need to be sensitive to security, authorization, and access issues. These extra responsibilities mean that embedded devices are becoming more complex and require more raw computing power. That makes them slower to build and more difficult to manage and maintain.

There is a revolution occurring within the embedded systems arena that is making low-cost embedded network appliances a reality. A combination of inexpensive, high-performance processors and powerful software platforms that use operating systems like Linux are making it possible to network everything.

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