Kaiwan N Billimoria - Linux Kernel Programming

First, to my dear parents, Diana and Nadir "Nads", for showing me how to live a happy and productive life. To my dear wife, Dilshad (an accomplished financial advisor herself), and our amazing kids, Sheroy and Danesh thanks for all your love and patience.

Kaiwan N Billimoria

Writing this book took a long while; I'd like to thank the team from Packt for their patience and skill! Carlton Borges, Romy Dias, Vijin Boricha, Rohit Rajkumar, Vivek Anantharaman, Nithin Varghese, and all the others. It was indeed a pleasure working with you.
I owe a debt of gratitude to the very able technical reviewers Donald "Donnie" Tevault and Anil Kumar. They caught a lot of my mistakes and omissions and greatly helped make this book better.

Preface

This book has been explicitly written with a view to helping you learn Linux kernel development in a practical, hands-on fashion, along with the necessary theoretical background to give you a well-rounded view of this vast and interesting topic area. It deliberately focuses on kernel development via the powerful Loadable Kernel Module (LKM) framework; the vast majority of kernel projects and products, which includes device driver development, are done in this manner.

The focus is kept on both working hands-on with, and understanding at a sufficiently deep level, the internals of the Linux OS. In these regards, we cover everything from building the Linux kernel from source through understanding and working with complex topics such as synchronization within the kernel.

To guide you on this exciting journey, we divide this book into three sections. The first section covers the basics setting up a workspace required for kernel development, building the kernel from source, and writing your first kernel module.

The next section, a key one, will help you understand important and essential kernel internals the Linux kernel architecture, the task structure, and user and kernel-mode stacks. Memory management is a key and interesting topic we devote three whole chapters to it (covering the internals to a sufficient extent, and importantly, how exactly to allocate any free kernel memory). The working and deeper details of CPU scheduling on Linux round off this section.

The last section of the book deals with the more advanced topic of kernel synchronization a necessity for professional design and code on the Linux kernel. We devote two whole chapters to covering key topics within this.

The book uses the, at the time of writing, latest 5.4 Long Term Support ( LTS) Linux kernel. It's a kernel that will be maintained (both bug and security fixes) from November 2019 right through December 2025! This is a key point, ensuring that this book's content remains current and valid for years to come!

We very much believe in a hands-on approach: over 20 kernel modules (besides several user apps and shell scripts) on this book's GitHub repository make the learning come alive, making it fun, interesting, and useful.

We highly recommend you also make use of this book's companion guide, Linux Kernel Programming (Part 2).

It's an excellent industry-aligned beginner's guide to writing misc character drivers, performing I/O on peripheral chip memory and handling hardware interrupts. You can get this book for free along with your copy, alternately you can also find this eBook in the GitHub repository at: https://github.com/PacktPublishing/Linux-Kernel-Programming/tree/master/Linux-Kernel-Programming-(Part-2).