Heroes Happen Here Launch Events Attend the upcoming launch of three powerful new products, take a test drive, meet the teams, and leave with promotional copies of Windows Server 2008, Microsoft SQL Server 2008, and Microsoft Visual Studio 2008. Register here. »   Install What You Need with Windows Server 2008 Windows Server 2008 is Microsofts most full-featured server operating system yet, so it's ironic that one of its most exciting new features is an install option that cuts out most of the other features. Paul Rubens explores why a Server Core installation makes a great deal of sense in many instances. »   Simplify Big Business IT for Small and Midsize Companies Windows Small Business Server 2008 and Windows Essential Business Server 2008 deliver all-in-one solutions to help fuel growth for customers and partners. »   Q&A with Bob Muglia: Senior VP, Server and Tools Division Bob Muglia, senior vice president, Server and Tools Division, discusses Microsofts new interoperability principles and the steps the company is taking to increase the openness of its products. »   Q&A with Lutz Ziob, GM of Microsoft Learning Lutz Ziob, the general manager of Microsoft Learning, talks about how IT professionals can become certified heroes within their enterprises by getting trained and certified in Windows Server 2008. »

People new to Linux often hear that it has excellent support for all kinds of cards and that the device drivers are stable and fast. Sometimes, though, setting up devices under Linux is often not all plug-and-play. Below we try to demystify Linux device drivers, with the aim of smoothing device selection during installs.

Everything is a file

Skip this section if you aren't interested in the inside technical details.

Many modern operating systems have a method for installing special files to make hardware work. On the Apple Mac, for instance, the drivers for the hardware devices are usually special files that go in the System Extensions folder. Linux also has special files that it uses to control the hardware.

Linux device drivers work through special kernel code that directly accesses the hardware. To make the services that the card or other device offers available to normal user programs, the kernel uses the special files in /dev

One end of the file in /dev can be opened normally and the other end is attached to the kernel. That is of course an oversimplification, but I think you get the general idea: hardware, kernel, special file, user program and the same path back from user program to hardware. There are two forms of the kernel portion of this equation: compiled-in drivers that are coded in permanently when the kernel is built, and modules.

Next: All About Modules »