Real time operating system

I am new to Real time operating system.
How should i work on it.
I want to know
1) How RTOS work.
2) How is the program flow
3) How to design RTOS based application
4) How to port RTOS
5) How do we compile and link
6) How to download it in to Target
7) How to create Rom image in order to download it to target ROM