Book Image

Linux: Embedded Development

By : Alexandru Vaduva, Alex Gonzalez, Chris Simmonds
Book Image

Linux: Embedded Development

By: Alexandru Vaduva, Alex Gonzalez, Chris Simmonds

Overview of this book

Embedded Linux is a complete Linux distribution employed to operate embedded devices such as smartphones, tablets, PDAs, set-top boxes, and many more. An example of an embedded Linux distribution is Android, developed by Google. This learning path starts with the module Learning Embedded Linux Using the Yocto Project. It introduces embedded Linux software and hardware architecture and presents information about the bootloader. You will go through Linux kernel features and source code and get an overview of the Yocto Project components available. The next module Embedded Linux Projects Using Yocto Project Cookbook takes you through the installation of a professional embedded Yocto setup, then advises you on best practices. Finally, it explains how to quickly get hands-on with the Freescale ARM ecosystem and community layer using the affordable and open source Wandboard embedded board. Moving ahead, the final module 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 see how functions are split between processes and the usage of POSIX threads. By the end of this learning path, your capabilities will be enhanced to create robust and versatile embedded projects. This Learning Path combines some of the best that Packt has to offer in one complete, curated package. It includes content from the following Packt products: ? Learning Embedded Linux Using the Yocto Project by Alexandru Vaduva ? Embedded Linux Projects Using Yocto Project Cookbook by Alex González ? Mastering Embedded Linux Programming by Chris Simmonds
Table of Contents (6 chapters)

Much of the interaction between a computer system and the real world happens in real-time and so this is an important topic for developers of embedded systems. I have touched on real-time programming in several places so far: in Chapter 10, Learning About Processes and Threads, I looked at scheduling policies and priority inversion, and in Chapter 11, Managing Memory, I described the problems with page faults and the need for memory locking. Now, it is time to bring these topics together and look at real-time programming in some depth.

In this chapter, I will begin with a discussion about the characteristics of real-time systems and then consider the implications for system design, both at the application and kernel levels. I will describe the real-time kernel patch, PREEMPT_RT, and show how to get it and apply it to a mainline kernel. The last sections will describe how to characterize system latencies using two tools: cyclictest and Ftrace.

There...