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
About the Author
About the Reviewers

Filesystems for NOR and NAND flash memory

To use raw flash chips for mass storage, you have to use a filesystem that understands the peculiarities of the underlying technology. There are three such filesystems:

  • Journaling Flash File System 2, JFFS2: This was the first flash filesystem for Linux, and is still in use today. It works for NOR and NAND memory, but is notoriously slow during mount.

  • Yet Another Flash File System 2, YAFFS2: This is similar to JFFS2, but specifically for NAND flash memory. It was adopted by Google as the preferred raw flash filesystem on Android devices.

  • Unsorted Block Image File System, UBIFS: This is the latest flash-aware filesystem for both NOR and NAND memory, which is used in conjunction with the UBI block driver. It generally offers better performance than JFFS2 or YAFFS2, and so should be the preferred solution for new designs.

All of these use MTD as the common interface to flash memory.


The Journaling Flash File System had its beginnings in the software...