Ramtester in python

i am trying to write ramtester in python. i was able to make everything work, like download bit file and other settings for FPGA nad memory. the problem i am having is in the following code: xem.WriteToPipeIn(0x80, SDRAM_SIZE, buf). the error i get is

Traceback (most recent call last):
File “”, line 1, in -toplevel-
xem.WriteToPipeIn(0x80, SDRAM_SIZE, buf)
File “C:\Program Files\python2.4\ok.py”, line 118, in WriteToPipeIn
def WriteToPipeIn(*args): return _ok.FrontPanel_WriteToPipeIn(*args)
TypeError: Expected a pointer