When not to choose Linux

Is Linux suitable for your project? Linux works well where the problem being solved justifies the complexity. It is especially good where connectivity, robustness, and complex user interfaces are required. However, it cannot solve every problem, so here are some things to consider before you jump in:

• Is your hardware up to the job? Compared to a traditional Real-Time Operating System (RTOS) such as VxWorks or QNX, Linux requires a lot more resources. It needs at least a 32-bit processor and lots more memory. I will go into more detail in the Selecting hardware for embedded Linux section.
• Do you have the right skill set? The early parts of a project, the board bring-up, require detailed knowledge of Linux and how it relates to your hardware. Likewise, when debugging and tuning your application you will need to be able to interpret the results. If you don’t have the skills in-house you may want to outsource some of the work. Of course, reading this book helps!
• Is your system real time? Linux can handle many real-time activities as long as you pay attention to certain details, which I cover in depth in Chapter 21.
• Will your code require regulatory approval (medical, automotive, aerospace, and so on)? The burden of regulatory verification and validation might make another OS a better choice. Even if you do choose Linux for use in these environments, it may make sense to purchase a commercially available distribution from a company that has supplied Linux for existing products like the one you are building. These commercial Linux vendors include Siemens, Timesys, and Wind River.

Consider these points carefully. Probably the best indicator of success is to look around for similar products that run Linux and see how they did it, and follow best practices.