Book Image

Embedded Linux Development Using Yocto Project Cookbook - Second Edition

By : Alex Gonzalez
Book Image

Embedded Linux Development Using Yocto Project Cookbook - Second Edition

By: Alex Gonzalez

Overview of this book

The Yocto Project has become the de facto distribution build framework for reliable and robust embedded systems with a reduced time to market.You'll get started by working on a build system where you set up Yocto, create a build directory, and learn how to debug it. Then, you'll explore everything about the BSP layer, from creating a custom layer to debugging device tree issues. In addition to this, you’ll learn how to add a new software layer, packages, data, scripts, and configuration files to your system. You will then cover topics based on application development, such as using the Software Development Kit and how to use the Yocto project in various development environments. Toward the end, you will learn how to debug, trace, and profile a running system. This second edition has been updated to include new content based on the latest Yocto release.
Table of Contents (13 chapters)
Title Page
Packt Upsell

Using dynamic kernel tracing

Kprobes is a kernel debugging facility that allows us to dynamically break into almost any kernel function (except kprobe itself) to collect debugging and profiling information non-disruptively. Architectures can keep an array of blacklisted functions, which cannot be probed using Kprobes.

Because kprobes can be used to change a function's data and registers, it should only be used in development environments.

There are three types of probes:

  • kprobes: This is the kernel probe, which can be inserted into any location with more than one kprobe added at a single location, if needed.
  • jprobe: This is the jumper probe inserted at the entry point of a kernel function to provide access to its arguments. Only one jprobe may be added at a given location.
  • kretprobe: This is the return probe and triggers on a function return. Also, only one kretprobe may be added to the same location.

They are packaged into a kernel module, with the init function registering the probes and the...