[Sony Xperia P, U, Sola, Go] Hnk1:
I have come across so many questions about rooting, bootloader and flashing that I decided to give a brief idea what is it all about..

I will use as simple words as possible.

When you buy your phone, you are on STOCK ROM and KERNEL. (its from your mobile manufacturer)

Rom is the system on which phone works (like windows for PC) and KERNEL is programmed code that tells the phone how to function in accordance to the ROM.

ROM & KERNEL can be custom or stock. Customisation helps in running the phone according to our needs.

The STOCK ROM & KERNEL is usually based on all rounder to fit most of the users . However, some of us want more from our phone in terms of battery life, performance, speed etc. However, increase battery may affect your performance but not necessarily. Thus modifications are used which are SPECIFIC for every model. this means you can't use one kernel/Rom for another model USUALLY. This will brick your phone. Some modifications in ROM for one model can help it to be used in another.

You decided to install a custom Rom/Kernel.

Well, the first thing ýou need to do is UNLOCK your bootloader. With unlocked bootloader, you can install all custom and stock Roms without any problem of your specific model. With locked bootloader, ýou might be able to install few custom Roms designed for locked bootloader.

BOOTLOADER is basically a lock in your phone which doesn't allow modifications to your phone by the company. Unlocking bootloader voids your warranty and stops automatic updates of your STOCK ROM. however, you can easily lock your bootloader again any time without company's knowledge and manually install STOCK Updates.

REMEMBER THIS COMES BEFORE ROOTING UNLESS YOU ARE INSTALLING A CUSTOM ROM WHICH IS PRE-ROOTED AND ALLOWS LOCKED BOOTLOADER.

ROOTING

This is basically modification to take over your system. It simply means that some system files which couldn't be modified can be changed. This simply means that now you have complete power of your ROM and hardware. You can change values , overclock your processor or put your hardware in hibernation to increase speed or enforce 3D gaming cards to play HD games which you couldnot play before. Usually apps are used to change these values. You will have SUPER USER OR SUPER SU added in your apps list.

FLASHTOOL :

This tool is from Sony to install ROMS and KERNEL in your Xperia.

This tool is use to install any kind of STOCK version. You can get UK STOCK version, USA Europe etc

ADVANTAGES OF ROOTING

- You get full access to your phone's Hardware and software

- You can Overclock CPU clock speed and make phone faster

- You can Install many mods to improve camera, audio and video playback quality

- You can Install Beats Audio Drivers to enhance audio output

- You can increase speaker / earphone volume using volume hack

- You can Install Custom ROMs and Apps

- You can take the hell out of your device and Improve user experience

Rooting is safe and reversible, You can unroot your phone if you want. It won't void you're warranty etc

SOME ROOT APPS WHICH CAN ENHANCE THE PERFORMANCE

DroidWall

Dual Mount SD Widget

Hexamob Recovery Pro

Keyboard Manager

LEDs Hack

Rot Call Blocker

Samba Filesharing

Titanium Backup

Chainfire 3D ........... gaming and using different Graphic modules to run heavy games

Control CPU.... overclock processor

DISADVANTAGES OF ROOTING

-Chance to brick your device if the wrong software gets flashed. This can be EASILY reversible

-Warranty is void. You can flash STOCK ROM again and no one will have a clue you did that. So it can be reversible.

-Because, after Rooting you give permission (programmes ask, its not default) to softwares. If you give it to a malicious software, it can result in Viruses. FLASHING again can help.

In all honestly, I am using rooted devices for over 2 years and I never had any problem with viruses however, I have bricked my device few times by accident. (I have flashed and rooted almost every one to two weeks and I am just going to do now after writing this :P)

This is a short synopsis of steps :

1.Unlock bootloader usually done from official website . Just google your phone name with unlock bootloader. For example : UNLOCK BOOTLOADER XPERIA U

Some phones have unlocked bootloaders (Samsung etc)

2.Root your phone , in Sony case, we usually use FLASH TOOL or Binary method.

UNLOCKING BOOTLOADER :

I will give you a rough idea!

Basically, when you buy your phone it is locked from the manufacturer so no changes can be made to the software(STOCK ROM & KERNEL ) and thus this way, they can stop users to modify their software which might result in damage and they do not want to be responsible for that. SO unlocking bootloader voids your warranty. However, this can be reversible.

Usually, you will need fastboot. It is part of SDK manager which is used for Android development.

What you usually do is that you go in CMD in windows (Type that in Run)

Go to the folder where fastboot you have placed. You will need to go in that folder to in CMD Eg. C:/fastboot/

Then you connect your phone in fastboot mode. Eg. Xperia U shows blue light in fastboot mode. It could vary though for other handsets.

The trick to boot into FASTBOOT is, switch off your phone. Then you hold down volume UP key. and while holding the key , you connect your phone to the PC via USB cable.

A BLUE LIGHT WILL TURN ON and this will show you are connected to fastboot.

Then you enter your key, taken from official Sony and unlock your bootloader.

More details here :

http://unlockbootloader.sonymobile.com/

If you have any questions or want to know the method, do not hesitate to ask.

I hope this helps!