OS Infomation For RH850 U2A16 OS

Hello,

the mcu In my project is RH850-F1KH-D8, the OS is RI850V4.

Now transplant the project to RH850-U2A16.

What is the corresponding OS, how can i get more infomation ablout the U2A16 OS.

ps. 

development environment: GHS(MULTI IDE )

Thanks.