While the shatter-proof water-proof Sony Experia Z is in wait for its official Android 4.2.2 Jellybean upgrade, it seems that the same firmware has leaked through web. A forum member of XDAdevelopers posted a thread with attachments to developer version of Android 4.2.2 for the Xperia Z (C6602/C6603). According to him, the software is only for uncloaked boot loaders and it is not official.
To flash your phone to Android 4.2.2 unofficial, you need to follow these requirements:
- Unlocked bootloader
- The phone should be on stock JellyBean ROM .253/.307
- Any existing kernel with recovery
If you’re following the above points, then it is easy to flash update.zip via recovery. The new ROM is prerooted and busybox installed, also the kernel has a working CWM. The author warns that the official firmware may be different in features such that some features could be added while others removed. [ screenshots- Courtesy :forum.xda-developers.com ]