Permission denied when trying to mount USB storage

I'm trying to mount USB storage using the "Terminal Emulator" app with the following commands: mount -t vfat -o rw /dev/block/sd* /storage/usb1 or su mount -t vfat -o rw /dev/block/sd* /storage/usb1 But I get a permission denied message. I've tried different su binaries. One of them is: http://e2e.ti.com/support/embedded/android/f/509/t/279726.aspx The shell command which I'm using is working in adb, but I have to execute it within an app. Without permissions, I cannot do that. So: 1. Is it possible to root this Android image (I'm using TI release for Beaglebone Black)? 2. OR, can I give permissions using chmod? If I can, which files should I give permission? 3. OR, is my approach wrong?