I'm new in writing video drivers for QNX 6.6, and any suggested tutorial how to do this will be very helpful.
I'm familiarized with:
a) Screen Graphics Subsystem Developer's Guide   
b) OpenWF Display Configuration Developer's Guide

Currently I've written my WFD.so driver with all functions implemented as stubs, set it as "wfd-dlls" in graphics.conf 
and after running Screen I received SIGSEGV error:
"Process 106518 (screen) terminated SIGSEGV code=1 fltno=11 ip=0804f538(/sbin/screen@main+0x50f) ref=0000045c".
My graphics.conf:

begin khronos
  begin egl display 1
  end egl display

  begin wfd device 1
    wfd-dlls = WFD.so
  end wfd devide
end khronos

begin winmgr
  begin globals
  end globals

  begin display hdmi
  end display

  begin class framebuffer
  end class

  begin mtouch
  end mtouch
end winmg

Thanks.