Book Image

Mastering Embedded Linux Programming

By : Chris Simmonds
Book Image

Mastering Embedded Linux Programming

By: Chris Simmonds

Overview of this book

Mastering Embedded Linux Programming takes you through the product cycle and gives you an in-depth description of the components and options that are available at each stage. You will begin by learning about toolchains, bootloaders, the Linux kernel, and how to configure a root filesystem to create a basic working device. You will then learn how to use the two most commonly used build systems, Buildroot and Yocto, to speed up and simplify the development process. Building on this solid base, the next section considers how to make best use of raw NAND/NOR flash memory and managed flash eMMC chips, including mechanisms for increasing the lifetime of the devices and to perform reliable in-field updates. Next, you need to consider what techniques are best suited to writing applications for your device. We will then see how functions are split between processes and the usage of POSIX threads, which have a big impact on the responsiveness and performance of the final device The closing sections look at the techniques available to developers for profiling and tracing applications and kernel code using perf and ftrace.
Table of Contents (22 chapters)
Mastering Embedded Linux Programming
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Summary


Device drivers have the job of handling devices, usually physical hardware but sometimes virtual interfaces, and presenting it to higher levels in a consistent and useful way. Linux device drivers fall into three broad categories: the character, the block, and the network. Of the three, the character driver interface is the most flexible and therefore, the most common. Linux drivers fit into a framework known as the driver model, which is exposed through sysfs. Pretty much the entire state of the devices and drivers is visible in /sys.

Each embedded system has its own unique set of hardware interfaces and requirements. Linux provides drivers for most standard interfaces, and by selecting the right kernel configuration, you can get the device operational very quickly. That leaves you with the non-standard components for which you will have to add your own device support.

In some cases, you can sidestep the issue by using generic drivers for GPIO, I2C, and so on, and write user space...