Those of you who got the Sony Xperia P LT22i and might expects for the Android 4.1.2 Jelly Bean update, well good news folks! The Android 4.1.2 test firmware recently leaks. XDA highly recognized developer [DooMLoRD] got the 4.1.2 Jelly Bean build 6.2.A.0.399 at hand. This is a round-up firmware or beta-test build and not completely a whole version, since the GSM support has disabled to make calls.
But for those devs and advance users who might interested to run a test and wants to sneak out on what’s new for the upcoming Android 4.1.2 Jelly Bean in Sony Xperia P may grab this firmware version 6.2.A.0.399 with kernel version number 3.0.8 and manually flash it via SD card update zip and fastboot mode.
Just refer to DooMloRD XDA-Developers original thread (source link below) and follow any further instructions.