Book Image

GNU/Linux Rapid Embedded Programming

By : Rodolfo Giometti
Book Image

GNU/Linux Rapid Embedded Programming

By: Rodolfo Giometti

Overview of this book

Embedded computers have become very complex in the last few years and developers need to easily manage them by focusing on how to solve a problem without wasting time in finding supported peripherals or learning how to manage them. The main challenge with experienced embedded programmers and engineers is really how long it takes to turn an idea into reality, and we show you exactly how to do it. This book shows how to interact with external environments through specific peripherals used in the industry. We will use the latest Linux kernel release 4.4.x and Debian/Ubuntu distributions (with embedded distributions like OpenWrt and Yocto). The book will present popular boards in the industry that are user-friendly to base the rest of the projects on - BeagleBone Black, SAMA5D3 Xplained, Wandboard and system-on-chip manufacturers. Readers will be able to take their first steps in programming the embedded platforms, using C, Bash, and Python/PHP languages in order to get access to the external peripherals. More about using and programming device driver and accessing the peripherals will be covered to lay a strong foundation. The readers will learn how to read/write data from/to the external environment by using both C programs or a scripting language (Bash/PHP/Python) and how to configure a device driver for a specific hardware. After finishing this book, the readers will be able to gain a good knowledge level and understanding of writing, configuring, and managing drivers, controlling and monitoring applications with the help of efficient/quick programming and will be able to apply these skills into real-world projects.
Table of Contents (26 chapters)
GNU/Linux Rapid Embedded Programming
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

The root filesystem (rootfs)


The root filesystem (rootfs) is the main filesystem for an UNIX-like operative system. It contains the very critical files needed for the whole system to work (for instance, the init process), so if the root filesystem gets corrupted, the system will not work at all!

The root filesystem is the first filesystem the kernel mounts at boot, and it is never unmounted.

A rootfs can be used on several different types of storage devices (disks, flashes, and so on). A filesystem can stay in the RAM or even over the network, and according to the storage device where it's placed on, it can have different formats. This is because it has to take into account some special feature of the underlying storage media. In a typical GNU/Linux system, a rootfs type can be (mostly) EXT3/EXT4 or JFFS2/UBIFS. The first two formats are the standard Linux filesystems used into hard disks, USB storage devices, microSDs, and other block devices, while the JFFS2 and UBIFS are filesystems used...