rtos +selection
Well Nikhil,
Let me correct some mistakes in your post.
The uC/OS-II is royalty free. This is correct. But, you will get the RTOS libraries freely for Intel (PC) core which you can use for the simulation of all the Real Time concepts for study purpose.
In practice, you have to pay for the system files when you go for a specific target (as the processor registers will vary). Suppose I go for Rabbit-3000 core, the RTOS files will be diff for boot code as in Intel, for which you have to pay the money. Also, if you need some extra packages like embedded SNMP to implement, you have to purchase this library saparately.
Ya; it's true that RTOS application has to be designed keeping the hard memory constraints and stack size always in mind.
regds..,
Abid