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 process memory map

Each running process in user space has a process map that we can inspect. These memory maps tell us how a program's memory is allocated and what shared libraries it is linked to.

You can see the memory map for a process through the proc filesystem. As an example, here is the map for the init process, PID 1:

# cat /proc/1/maps
00008000-0000e000 r-xp 00000000 00:0b 23281745 /sbin/init
00016000-00017000 rwxp 00006000 00:0b 23281745 /sbin/init
00017000-00038000 rwxp 00000000 00:00 0        [heap]
b6ded000-b6f1d000 r-xp 00000000 00:0b 23281695 /lib/libc-2.19.so
b6f1d000-b6f24000 ---p 00130000 00:0b 23281695 /lib/libc-2.19.so
b6f24000-b6f26000 r-xp 0012f000 00:0b 23281695 /lib/libc-2.19.so
b6f26000-b6f27000 rwxp 00131000 00:0b 23281695 /lib/libc-2.19.so
b6f27000-b6f2a000 rwxp 00000000 00:00 0
b6f2a000-b6f49000 r-xp 00000000 00:0b 23281359 /lib/ld-2.19.so
b6f4c000-b6f4e000 rwxp 00000000 00:00 0
b6f4f000-b6f50000 r...