Yes yes, we know it’s Jelly Bean season right now with Android 4.1 having been released, but since the Galaxy S3 is a new device, devs are still trying to make CM9 based on Ice Cream Sandwich Android 4.0 run on it. The AT&T Galaxy S3 owners can now enjoy the AOSP aka pure Android experience as CM9 ROM nightlies have been released for it, by XDA Senior Member ChaosMinionX.
Nightlies are ROM builds that are built automatically now and then (every night by actual definition), incorporating all the latest changes made to the ROM’s code from the last nightly. Even though care is taken by the developers to make sure the code submitted for each nightly is stable, some things can go wrong with a new nightly as the builds are automatic and cannot be tested before release.
The ROM is in its early stages so there are a few things that do not work and there may be some bugs and issues. Currently, the following things do not work in the ROM (the most updated list can be found on the development page linked in step 3 of the guide):
- USB functions not working
- Camera Touch Focus is misbehaving; don’t use it for now.
- Voicemail Issues
- Camera Storage Point Issues
Let’s take a look at how you can install CM9 on your AT&T Galaxy S3.
This guide below is compatible only and only with the AT&T Galaxy S3. It’s not compatible with any other Galaxy S3, it only works for AT&T variant. Check your device’s model in Settings» About phone.
The methods and procedures discussed here are considered risky and you should not attempt anything if you don’t know completely what it is. If any damage occurs to your device, we won’t be held liable.
How to Install CM9 on AT&T Galaxy S3
- This procedure will wipe all your apps, data and settings (but it will NOT touch your SD cards, so don’t worry about those). Backup your Apps and important data — bookmarks, contacts, SMS, APNs (internet settings), etc. This Android backup guide would help you.
Important! Don’t forget to at least make a backup of your APN settings, which you can restore later if your data connection does not work after installing the ROM. Use the backup guide to find out how.
- Install ClockworkMod recovery using the guide → here.
- Download the latest nightly of the ROM from the official development page.
- Download the Google Apps package. This will install apps like Market, Gmail, etc. which are not present in the ROM.
Download Gapps | Filename: gapps-ics-20120429-signed.zip
- Copy the downloaded zip files from step 3 and step 4 to the internal SD card.
- Now, boot into ClockworkMod recovery. To do that, turn off your phone. Then, hold down Volume Up, Home and then the Power buttons together until the screen turns on, then let them go. The phone will boot into ClockworkMod recovery in a few seconds.
In recovery, use the volume buttons to scroll up/down and the home button to select an option.
- Select wipe data/factory reset, then select Yes on next screen to confirm. Wait a while till the data wipe is complete (this will not erase your personal files).
- Now select install zip from sdcard, then select choose zip from sdcard. Scroll to the ROM file on the sdcard and select it.
- Confirm installation by selecting Yes – Install _____.zip on the next screen. The ROM will start installing.
- After ROM installation completes, select choose zip from sdcard again, then select the gapps-ics-20120429-signed.zip file to install the Google apps package.
- After the installation is complete, select go back and then select reboot system now to reboot your phone and boot into CM9. First boot will take up to 5 minutes, so be patient and wait for the phone to boot up completely.
The CM9 nightly ROM is now installed on your AT&T Galaxy S3. Visit the official development page for more info and to get the latest updates on the ROM. Share your thoughts on the ROM in the comments below.