difference between Preemption and context switch

Question

A little intro,

I am currently writing a small (read tiny) RTOS kernel, well it\'s supposed to be monolithic with most stuff in the kernel. However I can\'t find much in

Answer 1

Rather than answering each of your enumerated questions, I'll do my best to service your (thankfully) bolded request:

A better alternative to answering all the questions would be if you could refer to me a freely available RTOS (or even a free book) for arm preferably

Micrium's uC/OS-III is a priority-based real-time kernel that (of course) supports both synchronous and asynchronous preemption. And, as luck would have it (and the reason I'm replying) is that there is a free book available, and also the source code is available.

Head over to the main page for uC/OS-III and on the left you'll see a link for a video talking about source code availability ("uC/OS-III Source is available").

As far as books go, go over to the projects page, and choose the book that most closely matches your target. 90% of the material is the same; only the CPU-specific stuff (like context switching, interrupts & initialization) will vary from book to book.

You'll have to register to download the book & the code, seems fair to me.

Good luck and have fun. Thanks for putting in bold your ultimate request / goal, that made this much easier.