Accessing Hardware from user space

The problem is that I don't know what's part doesn't work. I think, that VHDL code (not integrated in Nios) works. I've made a functional simulation and it seems to be all ok (when write signal is high I convert the the RGB triple). So , maybe, is a software problem. The (test (http://pastebin.com/f3a79f68c)) was written in good part by me following this (http://www.nioswiki.com/accessing_hardware_registers_from_user_space_programs) . In your opinion where is the problem ( vhdl, module, test) ? Sorry for my horrible english and my ignorance, but I'm very newbe about module programming.