Chapter 39. Kernel and Module Management

IN THIS CHAPTER

• The Linux Kernel

• Managing Modules

• When to Recompile

• Kernel Versions

• Obtaining the Kernel Sources

• Patching the Kernel

• Compiling the Kernel

• When Something Goes Wrong

• Reference

A kernel is a complex piece of software that manages the processes and process interactions that take place within an operating system. As a user, you rarely, if ever, interact directly with it. Instead, you work with the applications that the kernel manages.

The Linux kernel is Linux. It is the result of years of cooperative (and sometimes contentious) work by numerous people around the world. There is only one common kernel source tree, but each major Linux distribution massages and patches its version slightly to add features, performance, or options. Each Linux distribution, including Fedora, comes with its own precompiled kernel as well as the kernel source code, providing you with absolute authority over the Linux operating system. In this chapter, we will examine the kernel and learn what it does for us and for the operating system.

In this chapter, you also learn how to obtain the kernel sources, as well as how and when to patch the kernel. The chapter leads you through an expert's tour of the kernel architecture and teaches you essential steps in kernel configuration, how to build and install modules, and how to compile drivers in Fedora. This chapter also teaches you important aspects of working with GRUB, the default Fedora boot loader. Finally, the chapter's troubleshooting information will help you understand what to do when something goes wrong with your Linux kernel installation or compilation process. As disconcerting as these problems can seem, this chapter shows you some easy fixes for many kernel problems.

Most users find that the precompiled Fedora kernel suits their needs. At some point, you might need to recompile the kernel to support a specific piece of hardware or add a new feature to the operating system. If you have heard horror stories about the difficulties of recompiling the Linux kernel, you can relax; this chapter gives you all the information you need to understand when recompiling is necessary and how to painlessly work through the process.