Book Image

Mastering Embedded Linux Programming - Third Edition

By : Frank Vasquez, Chris Simmonds
5 (3)
Book Image

Mastering Embedded Linux Programming - Third Edition

5 (3)
By: Frank Vasquez, Chris Simmonds

Overview of this book

If you’re looking for a book that will demystify embedded Linux, then you’ve come to the right place. Mastering Embedded Linux Programming is a fully comprehensive guide that can serve both as means to learn new things or as a handy reference. The first few chapters of this book will break down the fundamental elements that underpin all embedded Linux projects: the toolchain, the bootloader, the kernel, and the root filesystem. After that, you will learn how to create each of these elements from scratch and automate the process using Buildroot and the Yocto Project. As you progress, the book will show you how to implement an effective storage strategy for flash memory chips and install updates to a device remotely once it’s deployed. You’ll also learn about the key aspects of writing code for embedded Linux, such as how to access hardware from apps, the implications of writing multi-threaded code, and techniques to manage memory in an efficient way. The final chapters demonstrate how to debug your code, whether it resides in apps or in the Linux kernel itself. You’ll also cover the different tracers and profilers that are available for Linux so that you can quickly pinpoint any performance bottlenecks in your system. By the end of this Linux book, you’ll be able to create efficient and secure embedded devices using Linux.
Table of Contents (27 chapters)
1
Section 1: Elements of Embedded Linux
10
Section 2: System Architecture and Design Decisions
18
Section 3: Writing Embedded Applications
22
Section 4: Debugging and Optimizing Performance

Summary

Every Linux device needs an init program of some kind. If you are designing a system that only has to launch a small number of daemons at startup and remains fairly static after that, then BusyBox init is sufficient for your needs. It is usually a good choice if you are using Buildroot as the build system.

If, on the other hand, you have a system that has complex dependencies between
services at boot time or runtime, and you have the storage space, then systemd would be the best choice. Even without the complexity, systemd has some useful features in the way it handles watchdogs, remote logging, and so on, so you should certainly give it serious thought.

Meanwhile, System V init lives on. It is well understood, and there are init scripts already in existence for every component that is important to us. It remains the default init for the Yocto Project reference distribution (Poky).

In terms of reducing boot time, systemd is faster than System V init for a similar workload...