Book Image

Learning Embedded Linux Using the Yocto Project

By : Alexandru Vaduva, Vaduva Jan Alexandru
Book Image

Learning Embedded Linux Using the Yocto Project

By: Alexandru Vaduva, Vaduva Jan Alexandru

Overview of this book

Table of Contents (20 chapters)
Learning Embedded Linux Using the Yocto Project
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
8
Hob, Toaster, and Autobuilder
9
Wic and Other Tools
Index

Linux real-time applications


Having a real-time operating system may not always be enough for everyone. Some people would also require real-time optimized applications running over the operating system. To make sure an rt-application can be designed and interacted with, the required determinism is necessary on the operating system and hardware. With regard to the hardware configuration, the requirements involve a low-latency interrupt handling. The mechanisms causing the ISR latencies should register values around tens of microseconds.

Regarding the kernel configuration required by real-time applications, the following configurations are necessary:

  • On-demand CPU scaling: Using this configuration helps with the creation of long-latency events when the CPU is in a low-power consumption mode.

  • NOHZ: This configurations disables the timer interrupt received by CPUs. With this option enabled, the latency spent on a CPU wake up is diminished.

To write an application, there are some things that need...