Using Linux in Embedded and Real-Time Systems
Since Linux is free, how can anyone build a profitable business based on offering commercial Linux distributions? It's a lot like bottled water—basically, what you pay for is services: packaging, delivery, quality assurance, etc. A word of caution: don't assume that every Linux-related program you download from the Web or obtain from a Linux CD can be freely reproduced and incorporated into the devices you develop. Some commercial Linux distributions that target embedded and real-time applications include proprietary third-party tools and utilities that require licensing and royalty payments if you incorporate them into multiple systems. In other words, read the fine print. For now, however, licensed Linux system software is the exception rather than the rule. With the market placing such a high value on Linux and its associated software being open source and royalty-free, most Linux software companies serving the embedded and real-time Linux market have opted to build their businesses based on selling tools, offering engineering services and providing technical support.
Given the strong position of Microsoft Windows in the end-user desktop/laptop market, it's unlikely the “average” desktop/laptop PC user will be running Linux any time soon. On the other hand, in embedded and real-time applications where the OS is an underlying and hidden technology supporting appliance-like operation of a non-computer device, several key features of Linux are making it a growing preference among system developers:
Source is available and free.
There are no runtime royalties.
Linux supports a vast array of devices.
Linux is truly a global standard.
Linux is sophisticated, efficient, robust, reliable, modular and highly configurable.
Time will tell, but it certainly looks as though Linux has already altered the embedded and real-time operating system landscape in a fundamental and irreversible way. The result? Developers now have greater control over their embedded OS; manufacturers are spared the costs and headaches of software royalties; end users get more value. And the penguins of the South Pole are celebrating.
Rick Lehrbaum (email@example.com) co-founded Ampro Computers, Inc. in 1983. In 1992, Rick formed the PC/104 Consortium and served as its chairman through January 2000. In October 1999, Rick turned his attention to embedded software, founding LinuxDevices.com—“the Embedded Linux Portal”.