All off topic discussions go here. Everything from the funny thing your cat did to your favorite tv shows. Non-programming computer questions are ok too.
Find a professor who is actively working on an OS project. Read his papers and related papers. Submit patches to his project if available in github or so. A professor has lot of power in American and European universities. You do stand a good chance if the professor likes you and you meet the universities minimum criteria. In India ( not sure about Pakistan), it is pretty much black and white ( high grades => guaranteed admit ). If you think about it, that's the only fair way to go about in our culture. An American or a European system will be greatly misused!.
--Thomas
Well, it would be a tedious task but I'm willing to give it a try.
Are you from India? By the way, here in Pakistan, something like 10% of top universities place emphasis on grades; the rest on college entrance test.