Reading and writing pio(nios) in uclinux

I'm not sure how it works in the latest versions of uClinux, but in the (old) version I use the build system generates a nios2_system.h header file from my .ptf that defines all my PIO addresses as a "np_pio" struct. It automatically names them na_<pio name>. You can then write/read to them directly from your application (assuming you aren't using an MMU). So, e.g., if you have a PIO named my_pio in SOPC builder then you can read/write it as follows:

#include "nios2_system.h"
  ...
  // Reads the PIO value.
  int currvalue = na_my_pio->np_piodata;
  // Writes a new value.
  na_my_pio->np_piodata = newvalue;
  ...