Book Image

Embedded Linux Projects Using Yocto Project Cookbook

By : Alex Gonzalez
Book Image

Embedded Linux Projects Using Yocto Project Cookbook

By: Alex Gonzalez

Overview of this book

Table of Contents (13 chapters)
Embedded Linux Projects Using Yocto Project Cookbook
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Building external kernel modules


The Linux kernel has the ability to load modules at runtime that extend the kernel functionality. Kernel modules share the kernel's address space and have to be linked against the kernel they are going to be loaded onto. Most device drivers in the Linux kernel can either be compiled into the kernel itself (built-in) or as loadable kernel modules that need to be placed in the root filesystem under the /lib/modules directory.

The recommended approach to develop and distribute a kernel module is to do it with the kernel source. A module in the kernel tree uses the kernel's kbuild system to build itself, so as long as it is selected as module in the kernel configuration and the kernel has module support enabled, Yocto will build it.

However, it is not always possible to develop a module in the kernel. Common examples are hardware manufacturers who provide Linux drivers for a wide variety of kernel versions and have an internal development process separated from...