[U-Boot] The command "nand write.yaffs" is not working correctly

[Peter Pan]

I'm recently facing a yaffs2 image write problem in u-boot.

In u-boot console, I write the yaffs2 image in ram to an already erased nand
flash with command "nand write.yaffs ${loadaddr} ${nandrootoffset}
${filesize}".
After that, if I boot using a ramdisk and mount that yaffs2 partition,
I can only
see a folder of "lost+fount". I seems nothing has been written into
that partition.

But if now I write this image using "nandwrite -a -o /dev/mtd4
yaffs2.img" and mount
that partition, it's working.

Anyone met that problem already? Or if I did anything wrong?