The kernel manages the hardware of every Linux system and makes it available to the various processes. Although the information provided in this chapter will not make you a kernel hacker, you will learn how to perform a kernel update and how to compile and install a custom kernel. If you follow the instructions in this chapter, the previous kernel will remain functional and can be booted if necessary.
The kernel that is installed in the /boot directory is configured for a wide range of hardware. Normally, there is no need to compile a custom kernel, unless you want to test experimental features and drivers.
Several Makefiles are provided with the kernel to automate the process. Select the hardware settings and other kernel features. As you need to know your computer system pretty well to make the right selections, modifying an existing and working configuration file is recommended for your first attempt.