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)

Summary

Being able to update the software on devices in the field is at the very least a useful attribute, and if the device is connected to the internet, it becomes an absolute must. And yet, all too often it is a feature that is left until the last part of a project, on the assumption that it is not a hard problem to solve. In this chapter, I hope that I have illustrated the problems that are associated with designing an effective and robust update mechanism, and also that there are several open-source options readily available. You do not have to reinvent the wheel any more.

The approach used most often, and also the one with most real-world testing, is the symmetric image (A/B) update, or its cousin the asymmetric (recovery) image update. Here, you have the choice of SWUpdate, RAUC, and Mender. A more recent innovation is the atomic file update, in the form of OSTree. This...