Android 4.3 Jelly Bean ROM for the HTC One leaked ahead of its official release and it is designed for the international version. AT&T subscribers using HTC One can now upgrade their device to Android 4.3 using CyanogenMod 10.2 custom firmware.

Android 4.3 CyanogenMod 10.2

Owners of the HTC One AT&T variant can get the newest Android 4.3 Jelly Bean by manually installing the CyanogenMod or CM 10.2 custom firmware on their handset. It is a customised, aftermarket firmware build based on the Android Open Source Project or AOSP, designed to enhance the performance of the official Android ROM released by vendors and network carriers.

Warning: CyanogenMod 10.2 is a custom and unofficial firmware for the HTC One AT&T variant. Manually upgrading your smart phone may cause damage on your device and we are not responsible for any damages which may occur. Read, follow and understand the instructions to prevent damaging the HTC One. Do this at your own risk.

Requirements:

- Designed for the HTC One AT&T variant. Flashing the ROM to other variants may cause unforeseen consequences.

- Create a backup of all your personal information, settings and data files stored on your HTC One AT&T Variant.

- Make sure that the battery level at least 50 per cent.

- Unlock the bootloader of the HTC One AT&T variant then install a custom recovery app such as ClockworkMod recovery.

- Install USB drivers necessary for HTC One AT&T variant on your computer.

- Enable the USB debugging mode on your device.

- Android Debug Bridge and Fastboot must be configured on your computer.

- Download the Android 4.3 CyanogenMod 10.2 custom firmware and the Google Apps package to your computer.

Flashing Instructions:

1. Connect the HTC One AT&T variant to your computer using a USB cable.

2. Copy and paste all downloaded zip files to the SD card of your HTC One AT&T smartphone without extracting any of them.

3. Disconnect the device from your computer and then switch it off.

4. Reboot into Bootloader or Fastboot mode by pressing volume down and power keys at the same time.

5. Connect your HTC One AT&T variant to the computer.

6. Go to the "android-sdk-windows-platform-tools" directory on your computer then launch a Command Window.

7. Enter the following commands:
fastboot flash boot boot.img

8. Then enter the next commands:
fastboot reboot

9. After that, follow the instructions on the phone's screen and select "bootloader" then "recovery."

10. Do a full wipe inside the recovery mode. Select "wipe data/factory reset" and "wipe cache partition." Then go to "advanced > wipe Dalvik cache."

11. Go back to the main menu of the recovery mode and install the CM 10.2. Select "install zip from SD card > choose zip from SD card." Search for the CM10.2 Android 4.3 zip file you have copied earlier and confirm its installation. Apply the same with the Google Apps package.

12. Once the installation has been completed, go back to the main menu and select "reboot system now."

13. The HTC One AT&T smartphone may take up to 5 minutes before reaching the home screen on its first time running the new ROM.

Well done! Your HTC One AT&T variant is now running Android 4.3 Jelly Bean OS with customisable options and enhanced system of CyanogenMod 10.2 firmware.

If you have any questions and comments, send your feedback to the TeamAndroid original page.