Originally Posted by kn007
... it didn't mount /dev/mmcblk0p1,when i use but the /mnt/mmc/mnt/us just have one tree 'document'
i don't known how to going down
Nothing is mounted in /mnt/mmc/mnt/us. You need to look in /mnt/us instead for the USB drive contents.
By "going down", if you mean using a linux shell command to move to the parent directory, you should do "cd .." for that.