Book Image

Linux Kernel Programming

By : Kaiwan N. Billimoria
Book Image

Linux Kernel Programming

By: Kaiwan N. Billimoria

Overview of this book

Linux Kernel Programming is a comprehensive introduction for those new to Linux kernel and module development. This easy-to-follow guide will have you up and running with writing kernel code in next-to-no time. This book uses the latest 5.4 Long-Term Support (LTS) Linux kernel, which will be maintained from November 2019 through to December 2025. By working with the 5.4 LTS kernel throughout the book, you can be confident that your knowledge will continue to be valid for years to come. You’ll start the journey by learning how to build the kernel from the source. Next, you’ll write your first kernel module using the powerful Loadable Kernel Module (LKM) framework. The following chapters will cover key kernel internals topics including Linux kernel architecture, memory management, and CPU scheduling. During the course of this book, you’ll delve into the fairly complex topic of concurrency within the kernel, understand the issues it can cause, and learn how they can be addressed with various locking technologies (mutexes, spinlocks, atomic, and refcount operators). You’ll also benefit from more advanced material on cache effects, a primer on lock-free techniques within the kernel, deadlock avoidance (with lockdep), and kernel lock debugging techniques. By the end of this kernel book, you’ll have a detailed understanding of the fundamentals of writing Linux kernel module code for real-world projects and products.
Table of Contents (19 chapters)
Section 1: The Basics
Writing Your First Kernel Module - LKMs Part 2
Section 2: Understanding and Working with the Kernel
Kernel Memory Allocation for Module Authors - Part 1
Kernel Memory Allocation for Module Authors - Part 2
Section 3: Delving Deeper
About Packt

Getting started with the localmodconfig approach

Now, let's quickly get started on creating a base kernel configuration for our new kernel by using the third approach we discussed previously – the localmodconfig technique. As mentioned, this existing kernel modules-only approach is a good one when the goal is to obtain a starting point for kernel config on an x86-based system by keeping it relatively small and thus make the build quicker as well.

Don't forget: the kernel configuration being performed right now is appropriate for your typical x86-based desktop/server systems. For embedded targets, the approach is different (as seen in the Kernel config for typical embedded Linux systems section). We further cover this practically in Chapter 3, Building the 5.x Linux Kernel from Source - Part 2, under the Kernel build for the Raspberry Pi section.

As described previously, first obtain a snapshot of the currently loaded kernel modules,...