[Yaffs] using yaffs wituoht OS

Hi
I am using yaffs2 in a board including SLC NANDFLASH and ARM micro-controller. I use no OS so I handle all of the codes by myself.
Unfortunately, I couldn't find complete document to implement yaffs, but I've tried to understand the details using available documents and codes.
My problem is that when I run the code yaffs_mount() return "-1". Where did I do wrong?
"
yaffs_start_up();
i=yaffs_mount("/nand");

"

Is there any complete example for using yaffs with NANDFLASH without OS?

Thanks for any help.
Amin