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

Getting BusyBox runit

To prepare the system for this chapter, we need to do the following:

  1. Navigate to the directory where you cloned Buildroot for Chapter 6, Selecting a Build System:
    $ cd buildroot
  2. Check to see if runit is provided by BusyBox:
    $ grep Runit package/busybox/busybox.config
    # Runit Utilities

    BusyBox runit was still an available option in the Buildroot 2020.02.9 LTS release at the time of writing. Revert to that tag if you can no longer find BusyBox runit in a later release.

  3. Undo any changes and delete any untracked files or directories:
    $ make clean
    $ git checkout .
    $ git clean –-force -d

    Note that git clean --force will delete the Nova U-Boot patch and any other files that we added to Buildroot in previous exercises.

  4. Create a new branch named busybox-runit to capture your work:
    $ git checkout -b busybox-runit
  5. Add BusyBox runit to a default configuration for the Raspberry Pi 4:
    $ cd configs
    $ cp raspberrypi4_64_defconfig rpi4_runit_defconfig...