I successfully installed the Yocto, and worked fine,but no idea how to reboot the system by command line. I tried the command "reboot", but the system looks like just shut down and power lamp still light. BTW the physical reboot button can work.
Here is Yocto Version: Poky ( Yocto Project Reference Distro ) 1.6.2
which BSP and board are you using?
Thanks, i got the cause of the problem, the board was modified by someone which i got.