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


Nobody can complain that Linux lacks options to profile and trace. This chapter has given you an overview of some of the most common ones.

When faced with a system that is not performing as well as you would like, start with top and try to identify the problem. If it proves to be a single application, then you can use perf record/report to profile it, bearing in mind that you will have to configure the kernel to enable perf and you will need debug symbols for the binaries and kernel. OProfile is an alternative to perf record and can tell you similar things. gprof is, frankly, outdated but it does have the advantage of not requiring kernel support. If the problem is not so well localized, use perf (or OProfile) to get a system-wide view.

Ftrace comes into its own when you have specific questions about the behavior of the kernel. The function and function_graph tracers give a detailed view of the relationship and sequence of function calls. The event tracers allow you to extract more...