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

Troubleshooting build failures

In the two preceding chapters, we learned how to build bootable images for QEMU, our Nova board, and the Raspberry Pi 4. But what happens when things go wrong? In this section, we will cover a number of useful debugging techniques that should make the prospect of wrangling Yocto build failures less intimidating.

To execute the commands in the subsequent exercises, you need to activate a BitBake environment, as follows:

  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-rpi

This sets a bunch of environment variables and puts you back in the build-rpi directory that we created in the previous chapter.

Isolating errors

So, your build failed, but where did it fail? You have an error message, but what does it mean and where did it come from? Do not despair. The first step in debugging is reproducing the bug. Once you can reproduce...