Book Image

Mastering Embedded Linux Programming - Second Edition

By : Chris Simmonds
Book Image

Mastering Embedded Linux Programming - Second Edition

By: Chris Simmonds

Overview of this book

Embedded Linux runs many of the devices we use every day, from smart TVs to WiFi routers, test equipment to industrial controllers - all of them have Linux at their heart. Linux is a core technology in the implementation of the inter-connected world of the Internet of Things. The comprehensive guide shows you the technologies and techniques required to build Linux into embedded systems. You will begin by learning about the fundamental elements that underpin all embedded Linux projects: the toolchain, the bootloader, the kernel, and the root filesystem. You’ll see how to create each of these elements from scratch, and how to automate the process using Buildroot and the Yocto Project. Moving on, you’ll find out how to implement an effective storage strategy for flash memory chips, and how to install updates to the device remotely once it is deployed. You’ll also get to know the key aspects of writing code for embedded Linux, such as how to access hardware from applications, the implications of writing multi-threaded code, and techniques to manage memory in an efficient way. The final chapters show you how to debug your code, both in applications and in the Linux kernel, and how to profile the system so that you can look out for performance bottlenecks. By the end of the book, you will have a complete overview of the steps required to create a successful embedded Linux system.
Table of Contents (17 chapters)

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:

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...