Most traditional real-time operating-system vendors, along with their respective tool chains, are threatened in one way or another by Linux. To existing commercial solutions, the most dangerous aspect of Linux is royalty-free distribution. For complex, one-of-a-kind projects, this holds no appeal. But, for distributors of over several hundred, even a few dollars per copy becomes expensive. There are royalty-free commercial operating systems. Still, you pay a big upfront fee for the rights to the operating system, and you may not get source code with it.
Yet, there's more to an operating-system choice than simply run-time distribution, and a few traditional real-time operating-system vendors are seeking to ride the Linux wave with their own unique contributions. For instance, at the end of last year, Lynx Real-Time Systems announced a five-phase strategy to co-opt and capture a lead in the embedded Linux market. This strategy includes Blue Cat Linux, a version of the Red Hat distribution tuned for embedded applications, and the availability of the Lynx 3.1 development environment, which allows developers to write code from a Red Hat Linux host to target Blue Cat.
More significantly, the next version of the LynxOS, due out at around the time this article is in print, will include full binary compatibility with Linux programs. This means that it implements the Linux applications-programming interface (API) as a part of the operating system. Much of this is based on POSIX calls used in both operating systems.
QNX Software Systems also is providing the ability to run Linux binaries on its QNX Neutrino real-time operating system. Some programs can run directly on the Neutrino. This will apply to programs and libraries written for the POSIX API, and compiled for processor architectures supported by Neutrino. Right now those are Intel and PowerPC. In the case of other Linux APIs, QNX offers a thin, 50-kbyte translation layer that maps calls to the appropriate POSIX or Neutrino calls.
QNX is supplementing this with a radical strategy to open a large part of the Neutrino operating-system source code. By the time this appears, readers will be able to download a full Neutrino environment for noncommercial use. The environment includes source code for about 70% of the OS—almost everything but the microkernel, process manager, and Photon embedded windowing system.
Why does QNX think this is better than a Linux solution? The company believes that this approach offers the best middle course between a closed, proprietary system and a fully open and possibly too dynamic alternative. QNX is ramping up a technical support and consulting group, similar to the typical Linux business model. Still, the company will continue to charge a royalty for commercial distribution.