mounting SD Card on uClinux

Hi

When i insert the SD card i get the below message and also can't mount the SD Card

root:/dev> mmc0: SD Status: Invalid Allocation Unit size.

mmc0: host does not support reading read-only switch. assuming write-enable.

mmc0: new SD card on SPI

mmcblk0: mmc0:0000 SD512 478 MiB

mmcblk0: p1

root:/dev> mount -t vfat /dev/mmcblk0 /mnt

mount: mounting /dev/mmcblk0 on /mnt failed: No such device

root:/dev> mount -t vfat /dev/mmcblk0p1 /mnt

mount: mounting /dev/mmcblk0p1 on /mnt failed: No such device

root:/dev>

I also format the sdcard with FAT32 and 512byte but it doesn't help

Please give me some suggestion to fix the problem