Update Sony Xperia U ST25i to Android 4.3 via CM 10.2 Custom ROM

Android 4.3 Jelly Bean updates are rolling out widely for many of the advanced smart phones. Even though some devices didn’t get those official ones but they can surely be updated with custom ROMs. With these un-officials it has become so easy to test and try those latest versions.

Few days back many of the Sony phones including Xperia Z got the 4.3. So how the Sony’s Xperia U will remain behind? Sony Xperia U owners may be glad to hear that Cyanogenmod 10.2 running on the latest Android 4.3 version is available to download now. Sony has yet to confirm the timeline of the official Android 4.3 roll out for this device, but till then you can test and enjoy it via the un-official custom ROM.

Also CM is considered as the best available Custom ROM out there. You must note that this ROM is in its initial stage and is still under development so it may contain some bugs. But don’t be upset as nightlies are updated weekly so they will be definitely cleared.

Known issues:

  • Wi-Fi Tethering and Wi-Fi direct.
  • Bluetooth.

Well saying about CM 10.2, it is all compact with advanced thrilling features which includes managing and applying thousands of compatible themes on your phone, enhanced sound processing with DSP equalizer, instant access to settings via notifications, many built-in improvements, security and system improvements, long press on Back button will totally quit all the running applications in the background, camera quality tweaks, battery saving tweaks for extended battery life and much more customization options. Due to such benefits, CM ROMs are growing rapidly with over 10 million users worldwide.

If you’re impatient and are eager to download it then head over to the further article for detail description on updating Sony Xperia U to 4.3 CM 10.2.


Flashing a Custom ROM will void your device warranty. Also this process of updating Sony Xperia U with CM 10.2 Custom ROM is kinda of much risk and even a slight mistake can cause severe damage to your device. So read the article line by line and implement everything as given properly and at your own risk. Neither we nor the developers are responsible if your mobile is crashed or anything happens to your phone. Although the chances of getting you device damaged or crashed are very low but still we strongly recommend you to follow all the instructions properly as they are mentioned below. Don’t try to apply anything by your own.



This given Custom ROM running on the latest Android 4.3 is compatible only and only with Sony Xperia U model number ST25i. So don’t try to implement it on any other device or any variant except the one mentioned as your device may get bricked or may result into unwanted outcomes. You can confirm the given number by matching with your device’s model number from Homescreen–> Menu–>Settings –> About Phone.


  • Due to low battery life it may happen that your device gets switched off during the flashing process. Hence it is strongly recommended to charge the battery of your mobile at least up to 80%.
  • For improving your battery life, follow this guide:
  1. How to Improve Battery Life of an Android Device (Tips).
  • Backing up all the data is very much essential since everything gets wiped in the last step of this procedure. So you must always remember to backup all your Phone data and settings including contacts, SMS/MMS and call logs etc. to external memory card or on your PC.
  • For backing up Contacts & Messages, use this article:
  1. How to Backup Android Contacts and Text Messages (SMS/MMS).
  • For backing up Call logs, APNs & EFS folder, use this article:
  1. How to backup Call logs, APNs and EFS folder from your Android Device.
  • Before proceeding to the actual installation procedure, ensure that you have unlocked the bootloader of your device. If you haven’t done it yet, follow this guide.
  • Also ensure that a Custom Recovery like Clockworkmod recovery is installed on your device which is required to flash any Custom ROM. If you haven’t installed it yet don’t worry, just go through this article to do so.

Procedure to update Sony Xperia U with CM 10.2 Custom ROM [Android 4.3]


  • Download the CM 10.2 Custom ROM from the given link below:

  1. Click Here to Download

Update: Android 4.4 KitKat is now available for Xperia U ST25i.

  • Download the Google Apps containing Gmail, Play store, maps etc. from the given link below:
  1. Click here to Download
  • Download the ADB and fastboot files which are required to flash the kernel
  1. Click here to Download
  • After downloading these files, connect your device to the computer, enable mass storage mode and transfer these files to your device external storage. Ensure that you are not placing them in the deep directories. Also remember not to extract them.
  • Now extract the ADB and fastboot files that you’ve downloaded earlier. You will find four files inside the fastboot folder.
  • Further extract the ROM package present on your PC using the winrar. You’ll get a boot.img which is nothing but a kernel. Copy this kernel file in the fastboot folder. So the folder will have total these five files inside it.
  1. adb.exe
  2. AdbWinApi.dll
  3. AdbwinUsbApi.dll
  4. fastboot.exe
  5. runme.lnk
  • Now you need to boot your phone in fastboot mode. For doing so, press & hold volume up button while connecting your phone to PC. This will trigger the fastboot mode in your mobile. Then open the Fastboot folder, where the 5 files are located. Double click on runme.lnk file to launch the command prompt window. Now you can use this command prompt to enter ADB & fastboot commands.
  • Type the following command in command prompt to flash the kernel file:
fastboot devices
  • As soon as you type this command you will see some random numbers on your screen, which is the indicator that your device is properly connected. Further on, enter the command:
fastboot flash boot boot.img
  • Once you do all the above thing as mentioned, disconnect the phone from PC and switch it off by long pressing Power button.
  • So now you need to flash the CM 10.2 Custom ROM. For doing so you need to enter into recovery mode.
  • Firstly switch off your device, switch it on again, while phone is restarting (during boot logo & LED turns blue), press and tap Volume up button. In this way you can enter into recovery mode.
  • The first thing after entering in recovery mode is to make a nandroid backup of your current ROM which includes backup of your contacts, messages, apps, memos, call-logs etc. almost everything. This is highly recommended in case of some failure after flashing this ROM. For detailed process of taking nandroid backup follow our guide:
  1. How to Backup whole ROM/Firmware via Clockworkmod (CWM) recovery.
  • After taking the nandroid backup navigate to the ‘install zip from sdcard’ located on recovery mode & then ‘choose zip from sdcard’. Once you click on it, all your folders and files present on SD card will be seen. Now navigate to CM 10.2 ROM file which you’ve copied earlier & simply select it. Confirm the installation by pressing ‘Yes’. The installation process will begin now.
  • ROM installation process will complete in just a few minutes. Now as soon as the ROM gets flashed, select ‘wipe data/factory reset’ followed by ‘wipe cache partition’ on the recovery mode itself. This will wipe all the data & caches from the phone memory respectively.
  • In this way the CM 10.2 ROM is successfully flashed. But wait, the process is not yet finished since the flashing of GApps is remained. Follow the same above procedure for flashing Google Apps. But remember not to perform the last step of wiping data after installation of Google Apps.
  • Once everything mentioned above is done, restart your device by pressing ‘reboot system now’ from the Recovery mode. Note that the first boot always takes a minute but after that it will restart smoothly.

Note: If you don’t like this ROM and want to restore back your previous Rom due to some issue, you can do that by simply going back to the Recovery mode through the method given above and select ‘backup and restore’ option and then on next screen select ‘restore’.


This is it! CM 10.2 Custom ROM based on the latest Android 4.3 version has been successfully installed on your Sony Xperia U ST25i. Enjoy and experience the exceptionally new look and smooth performance of your device with this ROM. If you face any kind of difficulty, trouble or have any issue with this stuff then don’t hesitate to inform us. Just drop your problem through the comments given below. All your suggestions and problems will be pleasingly accepted and an exact solution will be given as soon as possible.

Comments (12)
  1. sarvesh July 27, 2016
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