You're reading from Mastering Embedded Linux Programming Create fast and reliable embedded solutions with Linux 5.4 and the Yocto Project 3.1 (Dunfell)

Product type Paperback

Published in May 2021

Publisher Packt

ISBN-13 9781789530384

Length 758 pages

Edition 3rd Edition

Languages

C++

Tools

Linux

Concepts

Embedded Systems

Authors (2):

Frank Vasquez

Mr. Chris Simmonds

View More author details

Table of Contents (27) Chapters

Preface

1. Section 1: Elements of Embedded Linux

2. Chapter 1: Starting Out FREE CHAPTER

3. Chapter 2: Learning about Toolchains

4. Chapter 3: All about Bootloaders

5. Chapter 4: Configuring and Building the Kernel

6. Chapter 5: Building a Root Filesystem

7. Chapter 6: Selecting a Build System

8. Chapter 7: Developing with Yocto

9. Chapter 8: Yocto Under the Hood

10. Section 2: System Architecture and Design Decisions

11. Chapter 9: Creating a Storage Strategy

12. Chapter 10: Updating Software in the Field

13. Chapter 11: Interfacing with Device Drivers

14. Chapter 12: Prototyping with Breakout Boards

15. Chapter 13: Starting Up – The init Program

16. Chapter 14: Starting with BusyBox runit

17. Chapter 15: Managing Power

18. Section 3: Writing Embedded Applications

19. Chapter 16: Packaging Python

20. Chapter 17: Learning about Processes and Threads

21. Chapter 18: Managing Memory

22. Section 4: Debugging and Optimizing Performance

23. Chapter 19: Debugging with GDB

24. Chapter 20: Profiling and Tracing

25. Chapter 21: Real-Time Programming

26. Other Books You May Enjoy

Summary

Linux has sophisticated power management functions. I have described four
main components:

CPUFreq changes the OPP of each processor core to reduce power on those that are busy but have some bandwidth to spare, and so allow the opportunity to scale the frequency back. OPPs are known as P-States in the ACPI specification.
CPUIdle selects deeper idle states when the CPU is not expected to be woken up for a while. Idle states are known as C-States in the ACPI specification.
Runtime pm will shut down peripherals that are not needed.
System sleep modes will put the whole system into a low power state. They are usually under end user control, for example, by pressing a standby button. System sleep states are known as S-States in the ACPI specification.

Most of the power management is done for you by the BSP. Your main task is to make sure that it is configured correctly for your intended use cases. Only the last component, selecting a system sleep state...