[Yaffs] XD wiht YAFFS

Hi all
I am developing low level interface driver for XD(extreme digital)
controller and need to interface it with application layer via file
system. shall i use flash file system(YAFFS) for interfacing or FAT
system for interface? which file system will be suites the needs?

also i need to know on what basis we need to select file system interface.

can any one help me on this?

thanks in advance

pandi