FPGA flash memory programming
If you read carefully the wiki page that you mentioned, you can find the following tip:


  When you execute the 'nios2-flash-programmer' command, you may get an error like:
  
  No EPCS layout data - looking for section [EPCS-010216]
  
  In such case, please refer the Altera forum page for the 'nios2-flash-programmer' or the section
  "A. Non-Standard Flash Memories" of "Nios II Flash Programmer User Guide" at pp.23.


Nios II Flash Programmer User Guide Appendix A: Non-Standard Flash Memories can be found here, pp. 27.