[Sony Xperia P, U, Sola, Go] ashqmallik:
For now, charge your battery first. U atleast need to have 80% charge before u can fastboot/flash your phone.

- (Only If Your Phone Doesnt Start) Press Power Button+Volume Up for some 10/15 seconds, u will get three vibrations which mean u just hard reset the phone. It normally takes about 2/3 minutes to boot up a phone after a new flash or kernel has been installed. If not then follow the the below instructions after the hard reset and see if it works.

- Assuming that you have already got the downloaded ftf (Firmware file) saved in the FIRMWARE folder of flashtool, if not then save it.

- Open up your flashtool.

- Press and hold the VOLUME DOWN key.

- Keep it pressed, connect the USB cable to your PC (assuming that u already have the usb connected to the phone)

- Release the Volume Down key when phone's GREEN LED lights

- Click the flash button (yes: the thunder icon up left)

- Select "Flahsmode" and click "OK"

- Select your desire firmware and click "OK", DON'T TOUCH ANYTHING ELSE

- Flashtool will prepare the files for flashing, just be patient

- Flashtool will start flashing automatically, let it finish to 100%

- At the end, Flashtool will prompt a line saying u need to check Unknown Sources And USB Debugging mode and thats when u know that u have successfully flashed a stock/custom ROM.

- Disconnect the phone, power up and give it some minute to boot up and work.

- Have fun :highfive:

HOW TO ROOT:

Depending on the Firmware/ROM the rooting method varies, i use Advanced Kernel Build14 on my new stock ICS firmware but always used DoomKernelv0.4+Recovery to Root Stock GB firmwares

You Can Download Any One Of them:

- AdvancedKernel14(Fastboot) For ICS

- DoomKernels(Fastboot+Recovery) Thread

How to Fastboot and just Root without Recovery and back to STOCK KERNEL:

First of all i will advice you to do this if ONLY you are planning to root your phone but want to come back on your stock kernel. Its a good thing to do if you have just flashed a new firmware like 6.0.A.2.45

Here's what you do:

[ requirements ]

# bootloader of the device is UNLOCKED

# Download and install FASTBOOT DRIVERS (DoomLord)

# Downlaod and Unzip FASTBOOT BINARIES

- Unplugged your USB from pc and Turn Off your phone

- Rename Advanced Kernel Build 14 to kernel.elf or unzip DoomlordKernelv0.4, unzip it and copy kernel.elf

- Open Fastboot Binaries folder

- Go To Fastboot folder, paste the kernel.elf file

- Press and hold VOLUME UP key.

- Keep it pressed and connect your phone and pc through USB.

- BLUE LED light will turn on means you are in fastboot mode, release the key.

- Fastboot folder opened, press SHIFT+RIGHT MOUSE button on the screen and choose Open Command Window here.

- Type

to check if your phone is connected properly and if it is, something like PSDN : xxxxx will be shown.

- Type

- Give it some seconds as it will load the kernel on the phone.

- Type

and your phone will restart. Give it some minute and it will boot up plus you will have root access :highfive:

ONLY IF YOU WANT TO GO BACK ON STOCK KERNEL WITH ROOT ACCESS:

- Assuming you have 7zip installed in your system, if not then google, download and install the programme.

- Right click on the ftf (firmware) file.

- Choose 7zip > Open Archive

- Click kernel.sin > Extract and save it anywhere in your PC

- Connect your phone through USB (You Can do it even if your phone is ON)

- Click the THUNDER ICON.

- Choose FASTBOOT. Choose OK.

- Click Reboot into fastboot mode (via ADB) if it gives error on flashtool then click REBOOT INTO FASTBOOT MODE ( via FASTBOOT)

- The Phone will turn off and will automatically go into fastboot mode ( BLUE LED )

- Click SELECT KERNEL TO FLASH

- Choose kernel.sin

- Give the kernel some seconds to flash and the phone will restart.

- You will see the SONY logo again if you have done it correctly ( YES YOU WILL because you just successfully flashed the stock kernel)

- Wait for some minute and the phone will reboot with stock kernel still with root access to it.

ALTERNATIVE WAY TO FLASH THE kernel.sin :

- Copy and paste the kernel.sin file over at the fastboot folder in fastboot binaries. Delete the kernel.elf

- Type fastboot devices

- Type fastboot flash boot kernel.sin

- Type fastboot reboot

:highfive: :highfive:

Follow the above steps and you will definitely have a success