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

Depending on other services

I mentioned how some services like connmand and bluetoothd require D-Bus. D-Bus is a message system bus that enables publish-subscribe interprocess communication. The Buildroot package for D-Bus provides a system dbus-daemon and a reference libdbus library. The libdbus library implements the low-level D-Bus C API but higher-level bindings to libdbus exist for other languages like Python. Some languages also offer alternative implementations of the D-Bus protocol that do not depend on libdbus at all. D-Bus services such as connmand and bluetoothd expect the system dbus-daemon to already be running before they can start.

Start dependencies

The official runit documentation recommends using sv start to express dependencies on other services under the control of runit. To make sure D-Bus is available before connmand starts, you should define your /etc/sv/connmand/run accordingly:

#!/bin/sh
/bin/sv start /etc/sv/dbus > /dev/null || exit 1
exec /usr...