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 (16 chapters)
15
Index

Choosing a kernel

The next step is to choose the kernel for your project, balancing the desire to always use the latest version of software against the need for vendor-specific additions.

Kernel development cycle

Linux has been developed at a fast pace, with a new version being released every 8 to 12 weeks. The way that the version numbers are constructed has changed a bit in recent years. Before July 2011, there was a three number version scheme with version numbers that looked like 2.6.39. The middle number indicated whether it was a developer or stable release, odd numbers (2.1.x, 2.3.x, 2.5.x) were for developers and even numbers were for end users. From version 2.6 onwards, the idea of a long-lived development branch (the odd numbers) was dropped as it slowed down the rate at which new features were made available to users. The change in numbering from 2.6.39 to 3.0 in July 2011 was purely because Linus felt that the numbers were becoming too large: there was no huge leap in the features...