Samsung has just started to push Galaxy S4's DUOS (GT-I9502) firmware to the KIES server as the device is soon going to be launched in various countries. Samsung always releases the firmware before the device itself and it's the same case with the Galaxy S4 DUOS, as well. The firmware is based on Android 4.2.2 Jelly Bean with Samsung's Nature UX 2.0 running on top of it. Currently, Samsung has only released the firmware for China, we hope other countries to follow soon.
Android Version: 4.2.2 – Build JDQ39
Build Date: April 17
The Galaxy S4 DUOS (GT-I9502) firmware is available for download from our Firmware Section. Now as the official firmware have been released, it's going to rain custom ROMs and custom kernels for the Galaxy S4 DUOS (GT-I9502).