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

Process or thread?

Many embedded developers who are familiar with real-time operating systems (RTOS) consider the Unix process model to be cumbersome. On the other hand, they see a similarity between an RTOS task and a Linux thread, and they have a tendency to transfer an existing design using a one-to-one mapping of RTOS tasks to threads. I have, on several occasions, seen designs in which the entire application is implemented with one process containing 40 or more threads. I want to spend some time considering whether this is a good idea or not. Let's begin with some definitions.

A process is a memory address space and a thread of execution, as shown in the following diagram. The address space is private to the process, so threads running in different processes cannot access it. This memory separation is created by the memory management subsystem in the kernel, which keeps a memory page mapping for each process and reprograms the memory management unit on each context switch...