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

Debugging kernel code

You can use kgdb for source-level debugging, in a manner similar to remote debugging with gdbserver. There is also a self-hosted kernel debugger, kdb, that is handy for lighter-weight tasks such as seeing whether an instruction is executed and getting the backtrace to find out how it got there. Finally, there are kernel Oops messages and panics, which tell you a lot about the cause of a kernel exception.

Debugging kernel code with kgdb

When looking at kernel code using a source debugger, you must remember that the kernel is a complex system, with real-time behaviors. Don't expect debugging to be as easy as it is for applications. Stepping through code that changes the memory mapping or switches context is likely to produce odd results.

kgdb is the name given to the kernel GDB stubs that have been part of mainline Linux for many years now. There is a user manual in the kernel DocBook, and you can find an online version at https://www.kernel.org/doc...