I have tried these commands for many times. What I confused is that after I enter the command 'set gpio mode=output state=asserted', the state of gpios do not change immediately. The state is initial state, only if you reboot the device, can the state be read into the system. What I really want is to get the state of gpios changed immediately after I entered the command. Which command I shoud use or Which command I should add, and where can I get them.