Book Image

Mastering Embedded Linux Programming - Third Edition

By : Frank Vasquez, Chris Simmonds
5 (3)
Book Image

Mastering Embedded Linux Programming - Third Edition

5 (3)
By: Frank Vasquez, Chris Simmonds

Overview of this book

If you’re looking for a book that will demystify embedded Linux, then you’ve come to the right place. Mastering Embedded Linux Programming is a fully comprehensive guide that can serve both as means to learn new things or as a handy reference. The first few chapters of this book will break down the fundamental elements that underpin all embedded Linux projects: the toolchain, the bootloader, the kernel, and the root filesystem. After that, you will learn how to create each of these elements from scratch and automate the process using Buildroot and the Yocto Project. As you progress, the book will show you how to implement an effective storage strategy for flash memory chips and install updates to a device remotely once it’s deployed. You’ll also learn about the key aspects of writing code for embedded Linux, such as how to access hardware from apps, the implications of writing multi-threaded code, and techniques to manage memory in an efficient way. The final chapters demonstrate how to debug your code, whether it resides in apps or in the Linux kernel itself. You’ll also cover the different tracers and profilers that are available for Linux so that you can quickly pinpoint any performance bottlenecks in your system. By the end of this Linux book, you’ll be able to create efficient and secure embedded devices using Linux.
Table of Contents (27 chapters)
1
Section 1: Elements of Embedded Linux
10
Section 2: System Architecture and Design Decisions
18
Section 3: Writing Embedded Applications
22
Section 4: Debugging and Optimizing Performance

Threads

The programming interface for threads is the POSIX threads API, which was first defined in the IEEE POSIX 1003.1c standard (1995) and is commonly known as pthreads. It is implemented as an additional part of the libpthread.so C library. There have been two implementations of pthreads over the last 15 years or so: LinuxThreads and Native POSIX Thread Library (NPTL). The latter is much more compliant with the specification, particularly regarding the handling of signals and process IDs. It is pretty dominant now, but you may come across some older versions of uClibc that use LinuxThreads.

Creating a new thread

The function you can use to create a thread is pthread_create(3):

int pthread_create(pthread_t *thread, const pthread_attr_t *attr,
      void *(*start_routine) (void *), void *arg);

It creates a new thread of execution that begins in the start_routine function and places a descriptor in pthread_t, which is pointed to by thread...