Android Open Source Project community has released AOSP 5.1 firmware for the Samsung Galaxy Grand Duos dual SIM smartphone. Almost everything except FM radio works out of the box including dual SIM functionality. AOSP firmwares are great for those who despise the heavy touchwiz interface that Samsung slapped onto a mid range device.
AOSP 5.1 ROM for Galaxy Grand Duos (I9082/I9082L). What is working?
RIL (Calls, SMS, Mobile Data)
Sensors (Accelerometer, Compass, Light, Proximity, etc.)
Video (playback & recording)
Audio (playback & recording)
And here are the installation instructions:
If you were on CM 10.1 or a stock ROM prior to 4.2, upgrade to stock 4.2 first.
Install ClockworkMod recovery with SELinux support (.tar) (.zip). Older CWM will result in a "status 7" error.
Reboot into recovery
Wipe data if coming from stock or other ROMs (You may get a "status 7" error if you fail to wipe.)
Install the ROM.