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

Build systems

The idea of a build system is to automate all the steps I have described up to this point. A build system should be able to build, from upstream source code, some or all of the following:

  • The toolchain

  • The bootloader

  • The kernel

  • The root filesystem

Building from an upstream source is important for a number of reasons. It means that you have peace of mind that you can rebuild at any time, without external dependencies. It also means that you have the source code for debugging and that you can meet your license requirements to distribute that to users where necessary.

Therefore to do its job, a build system has to be able to do the following:

  • Download a source from upstream, either directly from the source code control system or as an archive, and cache it locally

  • Apply patches to enable cross compilation, fix architecture-dependent bugs, apply local configuration policies, and so on

  • Build the various components

  • Create a staging area and assemble a root filesystem

  • Create image files in various...