Donatas,

I don't know much about KEIL, I hope somebody else will calrify this.

Could any one tell me, is it posible to know from the program is it running from external or internal ROM?

Well, I think it is not possible either from HEX file or Source code, to detrmine where the program is running from.

One possibility is that you know the microcontroller for which the program has been written, then from the size of code and internal code memory space of the micro, some conclusion can be drawn.

IA