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

Storage options


Embedded devices need storage that takes little power, is physically compact, robust, and reliable over a lifetime of perhaps tens of years. In almost all cases, that means solid state storage, which was introduced many years ago with read-only memory (ROM), but for the past 20 years it has been flash memory of some kind. There have been several generations of flash memory in that time, progressing from NOR to NAND to managed flash such as eMMC.

NOR flash is expensive but reliable and can be mapped into the CPU address space, which allows you to execute code directly from flash. NOR flash chips are low-capacity, ranging from a few megabytes to a gigabyte or so.

NAND flash memory is much cheaper than NOR and is available in higher capacities, in the range of tens of megabytes to tens of gigabytes. However, it needs a lot of hardware and software support to turn it into a useful storage medium.

Managed flash memory consists of one or more NAND flash chips packaged with a controller...