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

systemd


systemd defines itself as a system and service manager. The project was initiated in 2010 by Lennart Poettering and Kay Sievers to create an integrated set of tools for managing a Linux system including an init daemon. It also includes device management (udev) and logging, among other things. Some would say that it is not just an init program, it is a way of life. It is state of the art, and still evolving rapidly. systemd is common on desktop and server Linux distributions, and is becoming popular on embedded Linux systems too, especially on more complex devices. So, how is it better than System V init for embedded systems?

  • Configuration is simpler and more logical (once you understand it), rather than the sometimes convoluted shell scripts of System V init, systemd has unit configuration files to set parameters

  • There are explicit dependencies between services rather than a two digit code that merely sets the sequence in which the scripts are run

  • It is easy to set the permissions and...