Chapter Summary

You can build a Linux kernel from the source code. Sometimes you do not need to build a kernel; you can dynamically change many things by using boot options in /etc/grub.conf or by modifying /etc/sysctl.conf.

Before you can build a Linux kernel, you must have the kernel source files on the system. These files are located in /usr/src/linux. Once you have the source files, you need to clean the source tree, configure the kernel, compile the kernel and the loadable modules, and install the kernel and loadable modules.

The grub boot loader is a very small program that is used in the process of bringing the system up. You must configure the boot loader so that it recognizes the new kernel.

The dmesg utility displays the kernel-ring buffer, where the kernel stores messages. You can use this utility to help diagnose boot-time problems.