Question: how to create ovs bridge?
Answer: User can command "ovs-vsctl add-br <bridge> [-- set bridge br0 datapath_type=pica8]".
From PicOS2. ... 
Use the show <bridge_name> command to view the bridge details.
To delete the bridge and its ports, use the del-port command, then the del-br <bridge_name> command.
Enable STP in bridge.