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

Core files

Core files capture the state of a failing program at the point that it terminates. You don't even have to be in the room with a debugger when the bug manifests itself. So, when you see Segmentation fault (core dumped), don't shrug; investigate the core file and extract the goldmine of information in there.

The first observation is that core files are not created by default, but only when the core file resource limit for the process is non-zero. You can change it for the current shell using ulimit -c. To remove all limits on the size of core files, type the following command:

$ ulimit -c unlimited

By default, the core file is named core and is placed in the current working directory of the process, which is the one pointed to by /proc/<PID>/cwd. There are a number of problems with this scheme. Firstly, when looking at a device with several files named core, it is not obvious which program generated each one. Secondly, the current working directory...