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

The basics of software updates

Updating software seems, at first sight, to be a simple task: you just need to overwrite some files with new copies. But then your engineer's training kicks in as you begin to realize all the things that could go wrong. What if the power goes down during the update? What if a bug, not seen while testing the update, renders a percentage of the devices unbootable? What if a third party sends a fake update that enlists your device as part of a botnet? At the very least, the software update mechanism must be:

  • Robust, so that an update does not render the device unusable
  • Fail-safe, so that there is a fallback mode if all else fails
  • Secure, to prevent the device from being hijacked by people installing
    unauthorized updates

In other words, we need a system that is not susceptible to Murphy's law, which states that if something can go wrong, then it will go wrong, eventually. Some of these problems are non-trivial, however. Deploying...