Okay, we’ve just taken notice that the Samsung Galaxy Grand Duos has scored a Marshmallow update of its own too, albeit unofficially, as a AOSP custom ROM.

As hours pass by, we’re seeing Android 6.0 builds drop for one Android device after another. Today only, we saw Marshmallow update in the form of a custom ROM for Sony Xperia Z1, Z Ultra and Z1 compact.

We also are pretty close to OnePlus One Marshmallow update ROM, and we’re expecting — mainly, hoping — for more devices to get Marshmallow ROM love pretty soon.

Anyway, of all devices that have received the Marshmallow Custom ROMs so far, the Grand Duos is the cheapest them all. And Grand Duos getting the 6.0 ROM tells that the developer community is quite reliable — oh yes, that accounts most only if this ROM gets fixed over time and becomes good enough of a daily driver.

Bugs!

Attention please!!

The ROM is in alpha stage of development right now, and well, is not a daily driver at all. Far from it, actually.

Here’s why: first up, network isn’t working at all, meaning no calls, no sms, nothing. Next, Dual-SIM functionality is lost too. And there are other you could find below.

For what it’s worth, Wi-Fi, Bluetooth, seem to be working, along with camera, audio, video, etc.

→ Check out this page for latest on what’s working, and what’s not.

Downloads

  • Marshmallow custom ROM — Link | Download Mirror | File: aosp-6.0-20151013-UNOFFICIAL-i9082.zip (211.11 MB)
  • Google Apps (Gapps) — Link

Supported devices

  • Samsung Galaxy Grand Duos, model no. GT-i9082
  • Don’t try this on any other device than the one having model no. specified above.

Use the Droid Info app, to determine the codename of your Galaxy Grand Duos. If it is exactly the one specified above, then it should be compatible with the 6.0 custom ROM we have here.

Warning!

Warranty may be void of your device if you follow the procedures given on this page. You only are responsible for your device. We won’t be liable if any damage occurs to your device and/or its components.

Backup!

Backup important files stored on your device before proceeding with the steps below, so that in case something goes wrong you’ll have backup of all your important files.

How to Install

Required: You will need to have TWRP recovery installed on your device to be able to install Marshmallow custom ROM and Google Apps (Gapps). Check out our page on Galaxy Grand Duos TWRP recovery for this.

Step 1. Download the Marshmallow ROM and gapps file from above.

Step 2. Connect your device to PC and transfer the ROM and gapps file to it. Disconnect the device then. Remember the location of the files.

Step 3. Boot your Galaxy Grand Duos into recovery mode. If you are rooted, you can use Quick Boot app from play store. To manually boot into recovery mode, do this:

  • Power off your device and wait for 5-10 seconds until the device is fully switched off.
  • Press and hold Volume up + Home + Power button together and release them only when you see Samsung’s logo.

You will enter recovery mode soon, and should see TWRP recovery. If you see 3e recovery, then you need to install TWRP recovery for this (linked above).

Step 4. [Optional] Once in TWRP, create a backup of your device. Tap on Backup, and then select all the partitions for back. Now do the swipe action at bottom to start creating a backup for emergency cases. This backup is really a lifesaver!

Step 5. Do a Factory Reset. On TWRP’s main screen, tap on Wipe, then advanced wipe, and now make sure you have selected these partitions: dalvik cache, data, system and cache. Then do the Swipe action at bottom to confirm it.

Step 6. Now, install the ROM file. On TWRP’s homescreen, tap on Install, and then locate the ROM file and tap on it. Then do the Swipe action at bottom to begin flashing the update.

Step 7. Tap on Home button to go back. Now, install the Gapps the same way you installed Marshmallow ROM on your Galaxy Grand Duos.

Step 8. When it’s done, tap on Reboot system button to restart the device.

That’s it.

BTW, if you face force closes on apps, or Google Play services error, then install the ROM as said above again, but do not flash Gapps for now.

Need help? Let us know if you need any help with this via comments below.