Hi sai,
I have the same issue, which you are facing.
Let me know if you get any lead on this.
Also,
Freescale has provided some guide which will tell how to create our own FLASH device.
http://www.freescale.com/files/soft_dev_tools/doc/white_paper/CWFLASHPROWP.pdf
The above link may help you to go ahead.
I will le you know if I take this up...