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

The role of device drivers

As I mentioned in Chapter 4, Configuring and Building the Kernel, one of the functions of the kernel is to encapsulate the many hardware interfaces of a computer system and present them in a consistent manner to user space programs. The kernel has frameworks designed to make it easy to write a device driver, which is the piece of code that mediates between the kernel above and the hardware below. A device driver may be written to control physical devices such as a UART or an MMC controller, or it may represent a virtual device such as the null device (/dev/null) or a ramdisk. One driver may control multiple devices of the same kind.

Kernel device driver code runs at a high privilege level, as does the rest of the kernel. It has full access to the processor address space and hardware registers. It can handle interrupts and DMA transfers. It can also make use of the sophisticated kernel infrastructure for synchronization and memory management. However, you...