Youre trying to mount the mmc device instead of the partition, dmesg should show something like this when you insert the card: , mmc0: new SD card at address ff28 , mmcblk0: mmc0:ff28 SD064 60928KiB , mmcblk0: p1 , And the partition you want to mount then is /dev/mmcblk0p1, mind the partition label at the end. , So try this: , sudo mount -t vfat /dev/mmcblk0p1 /mnt , You might need to change the p1 to another number, look at your dmesg output. ,