change os to system

Signed-off-by: WuBo <wuborush@gmail.com>
Create empty dir for the future work

Signed-off-by: WuBo <wuborush@gmail.com>
Merge all the register to system.h

Signed-off-by: WuBo <wuborush@gmail.com>
Add watch dog

The system will reboot looping without right watch dog

Signed-off-by: WuBo <wuborush@gmail.com>