Linux Kernel in a Nutshell

Get the Performance and Behavior You Need from Linux with a Custom Kernel

Despite its large code base (more than seven million lines of code),
the Linux kernel is the most flexible operating system that has ever been
created. It can be used for a wide range of different systems, running on
everything from a radio-controlled model helicopter, to a cell phone, to the
majority of the largest supercomputers in the world. But, although modern Linux
distributions have become very accommodating-with support for every known
device, for sound, and even for power distributions-no Linux distribution
provides the exact kernel most of its users want. It may be a question of
hardware. Or, you may want to create something faster and smaller than the
kernel in available distributions, something customized for your specific
environment.

If you’ve reached the point in your Linux career where you need to build a
kernel or tweak the parameters of one you’re already running, Linux Kernel in a
Nutshell (O’Reilly) written by Greg Kroah-Hartman, a leading developer and
maintainer of the Linux kernel, will show you the way. The book provides
complete guidance on how to build and install a custom kernel in order to get
the performance and behavior you need from Linux.

Kroah-Hartman recalls that when the topic of the book was first presented to
him, he dismissed it as something that was already covered by the plentiful
documentation available on the kernel. “Surely someone had already written down
all of the basics needed in order to build, install, and customize the Linux
kernel, as it seemed to be a very simple task to me.” But, a Linux kernel
developer by trade, Kroah-Hartman admits that things that seem basic and simple
to him are often completely incomprehensible to others.

“After digging through the different HOWTOs and the Linux kernel Documentation
directory, I came to the conclusion that there was not any one place where all
of this information could be found,” he says. “It could be gleaned by
referencing a few files here and a few outdated websites there, but this was not
acceptable for anyone who did not know exactly what they were looking for in the
first place.”

Linux Kernel in a Nutshell was created with the goal of consolidating all the
existing information available on the subject-pulling together the information
scattered about the Internet as well as adding new and useful information that
Kroah-Hartman had learned by trial and error in his years of kernel development.

. The book focuses on version 2.6 of the Linux kernel, which has brought Linux
into the heart of corporate IT environments.
. It covers the entire range of tasks in kernel building and installation,
beginning with downloading the source.
. Includes guidelines for ensuring that your tools are in sync with your version
of the kernel, references and discussions of related topics, and recipes that
list what you’ll need to accomplish a wide range of tasks.
. No programming experience is needed to understand and use the book. Some
familiarity with using Linux and basic command-line usage is expected of the
reader.

Kroah-Hartman confesses that his secret goal in writing the book is to bring
more people into the Linux kernel development fold. “The act of building a
customized kernel for your machine is one of the basic tasks needed to become a
Linux kernel developer. The more people that try this out and realize that there
is not any real magic behind the whole Linux kernel process, the more people
will be willing to jump in and help out making the kernel the best that it can
be.”

Greg Kroah-Hartman has been writing Linux kernel drivers since 1999, and is
currently the maintainer for the USB, PCI, I2C, driver core, and sysfs kernel
subsystems. He is also the maintainer of the udev and hotplug userspace
programs, as well as being a Gentoo kernel maintainer, ensuring that his email
inbox is never empty. He is a contributing editor to Linux Journal Magazine, and
works for IBM’s Linux Technology Center, doing various Linux kernel related
tasks.