Remote Proc Tunnel Drivers
RPTUN driver is used for multi-cores’ communication.
Supported RPTUN drivers:
- RPMSG File System 
- RPMSG domain (remote) sockets 
- RPMSG UART Driver 
- RPMSG net Driver 
- RPMSG Usersock 
- RPMSG Sensor Driver 
- RPMSG RTC Driver 
- RPMSG MTD 
- RPMSG Device 
- RPMSG Block Driver 
- RPMSG IO expander 
- RPMSG uinput 
- RPMSG clk Driver 
- RPMSG syslog 
- RPMSG regulator