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
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Other profilers: OProfile and gprof


These two statistical profilers predate perf. They are both subsets of the functionality of perf, but they are still quite popular. I will mention them only briefly.

OProfile is a kernel profiler that started out in 2002. Originally, it had its own kernel sampling code, but recent versions use the perf_events infrastructure for that purpose. There is more information about it at http://oprofile.sourceforge.net. OProfile consists of a kernel-space component and a user space daemon and analysis commands.

OProfile needs these two kernel options to be enabled:

  • CONFIG_PROFILING in General setup | Profiling support

  • CONFIG_OPROFILE in General setup | OProfile system profiling

If you are using the Yocto Project, the user-space components are installed as part of the tools-profile image feature. If you are using Buildroot, the package is enabled by BR2_PACKAGE_OPROFILE.

You can collect samples by using this command:

# operf <program>

Wait for your application to...