Just about three weeks after the first Ice Cream Sandwich (ICS) Android 4.0 firmware leak, UCALC4 for the AT&T Galaxy S2 Skyrocket, a newer ICS firmware, UCLD2 has been leaked by Rootzwiki developer designgears, who in turn got it from an unknown source. We just hope that the final official Android 4.0 update comes soon, so we don’t get plagued by the usual barrage of firmware leaks that Samsung devices see.

Also, XDA modder yaldak has released a custom rooted version of the firmware leak, which can be installed from recovery. We have an installation guide below for both the actual firmware and the custom rooted version, so just go with whichever method you feel comfortable with. As always, this is a leaked firmware, so it’s not expected to be completely stable and can have some bugs and issues.

Read on to find out how you can install UCLD2 Ice Cream Sandwich firmware on your Galaxy S2 Skyrocket.

Compatibility

This firmware and the guide below are compatible only and only with the AT&T Samsung Galaxy S2 Skyrocket, model number i727. It’s not compatible with any other device and may render an incompatible device unusable. Check your device model in Settings » About phone.

Warning!

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.

Pre-Installation Requirements

  1. 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.
  2. (Only for Method 1) If you have Samsung’s PC software Kies installed, un-install it first because it may interrupt the flashing process.
  3. (Only for Method 1) Drivers! — it’s important you’ve the proper drivers installed.
    Download Drivers

How to Install UCLD2 Ice Cream Sandwich Firmware on Galaxy S2 Skyrocket

Method I: Using ODIN (Doesn’t require recovery or root access)

  1. Download the firmware by following the download link on the original release page. On the download page, click on the link next to the File URL text as shown below in screenshot to get the direct download link.

  2. Double-click on the downloaded I727UCLD2_OneClick.exe file to run Odin, which will be used to flash the firmware on your phone.
  3. Now, boot into download mode on the phone. To do this, turn off your phone. Plug in your USB cable to the computer, but not to the phone. Then, holding the Volume Up and Volume Down buttons on the phone, plug in the USB cable to the phone while holding those buttons. Once the Download mode screen shows up, let go of the buttons.
  4. The Odin screen will say “Added!!” in the message box below when the phone is connected to the computer. If it does not, make sure you have the proper drivers installed on the computer.
  5. Click on Start to start the flashing of UCLD2 on your Galaxy S2 Skyrocket.
  6. Wait for the procedure to finish. After flashing is complete, the phone will reboot, and you’ll get a PASS message (with green background) in Odin. You can now safely disconnect your phone.

    IMPORTANT Note: If ODIN gets stuck at some stage and doesn’t seem to be doing anything, do this — disconnect the phone from the PC, close ODIN, remove battery, re-insert it, and do the procedure again from Step 2. Same if you get FAIL message in Odin.

  7. If you run into any roadblocks while flashing the firmware, let us know and we’ll try to help you out.

Method 2: Using Clockworkmod Recovery (CWM)

  1. Make sure you have Clockworkmod (CWM) recovery installed on your phone. If not, you can use the guide → here.
  2. Download CWM flashable package. The download link below will give you a .torrent file, which you need to open with a torrent client like µTorrent or BitComet to download the actual ROM zip file named skyrocket-ucld2-ics-leak.zip.
    Download Link  (via XDA)
  3. Download the root package required for rooting the firmware.
    Download Link  |  Filename: su-bin-3.0.3.2-efghi-signed.zip
  4. Copy the zip files downloaded in step 2 and 3 to the internal SD card on your phone.
  5. Turn off the phone, then boot into recovery mode. For this, press and hold these 3 buttons together until Samsung’s screen shows up: Volume UP + Volume Down + Power. Phone will boot into CWM recovery. In recovery, use volume keys to scroll up and down between options and power/home key to select an option.
  6. Perform a wipe:
    1. Select wipe data/factory reset, then select Yes on next screen to confirm. Wait a while till the data wipe is complete.
    2. Select wipe cache then select Yes on next screen to confirm.
    3. Select mounts and storage, then select format system and select Yes on next screen to confirm. After system format is complete, select go back to go back to the main recovery menu.
  7. Select install zip from sdcard, then select choose zip from sdcard. Scroll to the ROM file on the SD card and select it. Confirm installation by selecting Yes – Install  skyrocket-ucld2-ics-leak.zip on the next screen. The ROM will start installing.
  8. After the ROM finishes installing, select go back to go back to the main recovery menu.
  9. Now repeat step 7, but this time select the root package file su-bin-3.0.3.2-efghi-signed.zip, and confirm installation on next screen by selecting Yes.
  10. After the installation is complete, select go back then select reboot system now to reboot the phone.

Using either of the above two methods, you can update to Ice Cream Sandwich Android 4.0 on your AT&T Galaxy S2 Skyrocket with the latest leaked firmware, UCLD2. Let us know what you think of it, in the comments below.