Where is the GPIO_BASE on Orange Pi?

TCH

I have an OrangePi PC+ and i'm trying to use the GPIO via /dev/mem and mmap, but without any avail. I cannot found any document which clearly states, where the GPIO registers starts in the memory. I've checked the source of WiringPi, it states it is 0x01C20800, but using that addres does not do anything. Are the registers themselves too, different from the registers in RaspberryPi?