Book Image

Mastering Embedded Linux Programming

By : Chris Simmonds
Book Image

Mastering Embedded Linux Programming

By: Chris Simmonds

Overview of this book

Mastering Embedded Linux Programming takes you through the product cycle and gives you an in-depth description of the components and options that are available at each stage. You will begin by learning about toolchains, bootloaders, the Linux kernel, and how to configure a root filesystem to create a basic working device. You will then learn how to use the two most commonly used build systems, Buildroot and Yocto, to speed up and simplify the development process. Building on this solid base, the next section considers how to make best use of raw NAND/NOR flash memory and managed flash eMMC chips, including mechanisms for increasing the lifetime of the devices and to perform reliable in-field updates. Next, you need to consider what techniques are best suited to writing applications for your device. We will then see how functions are split between processes and the usage of POSIX threads, which have a big impact on the responsiveness and performance of the final device The closing sections look at the techniques available to developers for profiling and tracing applications and kernel code using perf and ftrace.
Table of Contents (22 chapters)
Mastering Embedded Linux Programming
About the Author
About the Reviewers

Chapter 10. Learning About Processes and Threads

In the preceding chapters, we have considered the various aspects of creating an embedded Linux platform. Now it is time to start looking at how you can use the platform to create a working device. In this chapter, I will talk about the implications of the Linux process model and how it encompasses multi-threaded programs. I will look at the pros and cons of using single-threaded and multi-threaded processes. I will also look at scheduling and differentiate between timeshare and real-time scheduling policies.

While these topics are not specific to embedded computing, it is important for a designer of an embedded device to have an overview of these topics. There are many good reference works on the subject, some of which I reference at the end of the chapter, but in general, they do not consider the embedded use cases. In consequence, I will be concentrating on the concepts and design decisions rather than on the function calls and code.