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

What to update

Embedded Linux devices are very diverse in their design and implementation. However, they all have these basic components:

  • Bootloader
  • Kernel
  • Root filesystem
  • System applications
  • Device-specific data

Some components are harder to update than others, as summarized in this diagram:

Figure 10.1 – Components of an update

Figure 10.1 – Components of an update

Let's look at each component in turn.

Bootloader

The bootloader is the first piece of code to run when the processor is powered up. The way the processor locates the bootloader is very device-specific, but in most cases, there is only one such location, and so there can only be one bootloader. If there is no backup, updating the bootloader is risky: what happens if the system powers down midway? Consequently, most update solutions leave the bootloader alone. This is not a big problem, because the bootloader only runs for a short time at power-on and is not normally a great source...