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

Filesystems for managed flash

As the trend toward managed flash technologies continues, particularly eMMC, we need to consider how to use it effectively. While they appear to have the same characteristics as hard disk drives, the underlying NAND flash chips have the limitations of large erase blocks with limited erase cycles and bad block handling. And, of course, we need robustness in the event of losing power.

It is possible to use any of the normal disk filesystems, but we should try to choose one that reduces disk writes and has a fast restart after an unscheduled shutdown.

Flashbench

To make optimum use of the underlying flash memory, you need to know the erase block size and page size. Manufacturers do not publish these numbers as a rule, but it is possible to deduce them by observing the behavior of the chip or card.

Flashbench is one such tool. It was initially written by Arnd Bergman, as described in the LWN article available at https://lwn.net/Articles/428584...