Linux Kernel Programming, Second Edition: A practical guide to kernel internals, writing kernel modules, and synchronization

Welcome to Packt Early Access. We’re giving you an exclusive preview of this book before it goes on sale. It can take many months to write a book, but our authors have cutting-edge information to share with you today. Early Access gives you an insight into the latest developments by making chapter drafts available. The chapters may be a little rough around the edges right now, but our authors will update them over time.

You can dip in and out of this book or follow along from start to finish; Early Access is designed to be flexible. We hope you enjoy getting to know more about the process of writing a Packt book.

1. Chapter 1: Kernel Workspace Setup
2. Chapter 2: Building the 5.x Linux Kernel from Source - Part 1
3. Chapter 3: Building the 5.x Linux Kernel from Source - Part 2
4. Chapter 4: Writing Your First Kernel Module - LKMs Part 1
5. Chapter...

Kernel workspace setup

To get the most out of this book, it is very important that you first set up the workspace environment that we will be using throughout the book. This chapter will teach you exactly how to do this and get started.

Keeping size constraints in mind, the full and enhanced content of this chapter can be found within this book’s GitHub repository, here: http://www.packtpub.com/sites/default/files/downloads/9781803232225_Online_Chapter.pdf. I request that you download and read it in full. What follows here is an introduction to this first chapter of ours. Thanks!

In this chapter, we will install a recent Linux distribution (or “distro”) as a Virtual Machine (VM), and set it up to include all the required software packages. We will also clone this book’s code via its GitHub repository. Furthermore, this chapter also introduces a few useful projects that will help you along this exciting journey into the Linux kernel.

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Technical requirements

You will need a modern and preferably powerful desktop PC or laptop. Ubuntu Desktop specifies some recommended minimum system requirements for the installation and usage of the distribution here: https://help.ubuntu.com/community/Installation/SystemRequirements. I would definitely suggest you go with a system well beyond the minimum recommendations – as powerful a system as you can afford to use. This is because performing tasks such as building a Linux kernel from source is a very memory- and CPU-intensive process. It should be pretty obvious that the more RAM, CPU power, and disk space the host system has, the better!

Like any seasoned kernel developer, I would say that working on a native Linux system is best. However, for this book, we cannot assume that you will always have a dedicated native Linux box available to you. So, we shall assume that you are working on a Linux guest. Working within a guest VM also adds an additional layer of isolation...

Cloning this book’s code repository

The complete source code for this book is freely available on GitHub at https://github.com/PacktPublishing/Linux-Kernel-Programming_2E. You can clone and work on it by cloning the git tree, like so:

git clone https://github.com/PacktPublishing/Linux-Kernel-Programming_2E

The source code is organized chapter-wise. Each chapter is represented as a directory – for example, ch1/ has the source code for this chapter. The root of the source tree has some code that is common to all chapters, such as the convenient.h and klib.c source files, among others.

For efficient code browsing, I would strongly recommend that you always index the code base(s) with ctags and/or cscope. For example, to set up the ctags index on a source tree, just cd to the root of the source tree and type ctags -R. (If you haven’t already, please invest the time in learning code browsing tools like cscope and ctags.)

Unless noted otherwise...