Doubts using stdio.h

Cronus10 i read the thread you posted to me. So a disable the options: enable small c library, enable lightweight device driver api. But now, when i compile my code this error is shown: http://puu.sh/728hj.png.

I tried to fix it connecting the IRQ option in my Qsys design and it works, but sometimes when i try to reset the board pressing a button that i set to the reset pin nothing works anymore. So i need to turn off and turn on my board. I dont know exactly what the IRQ does, could help using this? If i disconnect this option my project doesn't work. Thank you!!!