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

Measuring power usage

For the examples in this chapter, we need to use real hardware rather than virtual. This means that we need a BeagleBone Black with working power management. Unfortunately, the BSP for the BeagleBone that comes with the meta-yocto-bsp layer does not include the necessary firmware for the Power Management IC (PMIC), so we will use
a pre-built Debian image instead. The missing firmware might exist in the meta-ti layer, but I did not investigate that. The procedure for installing Debian on the BeagleBone Black is the same as what we covered in Chapter 12, Prototyping with Breakout Boards, except for the Debian version.

To download the Debian Stretch IoT microSD card image for the BeagleBone Black, issue the following command:

$ wget https://debian.beagleboard.org/images/bone-debian-9.9-iot-armhf-2019-08-03-4gb.img.xz

10.3 (aka Buster) was the latest Debian image for AM335x-based BeagleBones at the time of writing. We will use Debian 9.9 for the exercises...