Do note that the ROM/firmware is NOT for daily use. It’s a beta release and many features might not be included which will be in the final release. Expect bugs and instability.
Do NOT try to flash this ROM on any other Sony phone. It is only intended for Xperia P (LT22i). Flashing it onto any other model may brick the phone indefinitely.
Firmware version 6.2.A.0.399
What’s not working on this ROM
- Baseband is not recognised.
- Kernel does not have working recovery.
Before installing Android 4.1.2 on Sony Xperia P make sure that your phone is rooted and is on stock ICS ROM. Don’t forget to backup all your important data. Make sure that all relevant drivers including USB drivers are installed and your phone is fully charged.
- Download the ROM
- Download the kernel
- Copy the ROM zip file on the SD card/removable storage.
- Boot into recovery mode.
- Depending on what recovery you have, navigate to select the ROM zip file and flash it.
- Reboot the device into fastboot.
- Extract the kernel zip file to get kernel.elf
- Use the command ‘ fastboot flash boot kernel.elf ‘ to flash the file using fastboot.
- Reboot from flashboot by using the commend ‘ flashboot reboot’.
- Upon restart you will have Android 4.1.2 on Sony Xperia P. Confirm it by going in settings>about
The steps above are taken from the original thread over at XDA. Make sure to visit it here for any more information on the above process and to thank the developer.