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

Capturing changes with devtool

In the previous chapter, you learned how to create a recipe for a helloworld program from scratch. A copy-paste approach to packaging recipes may work initially, but it soon becomes very frustrating as your project grows and the number of recipes you need to maintain multiplies. I'm here to show you a better way of working with package recipes – both yours and those that are contributed to upstream by some third party. It is called devtool and it is the cornerstone of Yocto's extensible SDK.

Development workflows

Before you get started with devtool, you want to make sure that you're doing your work in a new layer instead of modifying recipes in-tree. Otherwise, you could easily overwrite and lose hours and hours of work:

  1. First, navigate one level above the directory where you cloned Yocto.
  2. Next, set up your BitBake work environment:
    $ source poky/oe-init-build-env build-mine

    This sets a bunch of environment variables...