First attempt to root.......Please help....!

[Xperia80]

I have a xperia u (ICS 4.0.4) after update to the ICS my phone lags a lot and very slow.So i thought i should flash a JB(4.1 or 4.2) rom.I didn`t do it ,because JB roms have major bugs(camera not working).Soi am happy to stick with ICS.If you know any stable jelly ben rom please tell me.I found that xperia u, firmware version 6.1.1.b.1.100 is more smooth and less bugs ,but it`s not availbale to update via pc companion ,I am sorry that i ask previously ask questions ,i saw a uliwooly`s page about upgrading but  i don`t undstand that becaue this is my first attempt.please answer my questions.My English not good, sorry for that.this is like a exam paper  ,Thank you

current staus------------------>
Sony Xperia U (ST25i)
ICS 4.0.4
Firmware 6.1.1.b.1.54
        (Qustion look simillar but read whole question,put the question number and answer,because it easy to undstand)

1) how to find my phone root or unlocked bootloader(because i buy it from a friend) ?
2) Do i need to unlock my bootloader to flash a new firmware version ?
3) Do i need to unlock my bootloader to install a JB(4.1 or 4....) rom ?
4) what is the most smooth and lees bug sony firmware for xperia u (i found that it is 6.1.1.b.1.100 ,http://www.xperiablog.net/2013/06/22/new-firmware-released-for-xperia-u-6-1-1-b-1-100/) ?

5) Do you know any jelly bean rom for xperia u which is stable and no major bugs ?
6) Can i use sony flash tool to flash my phone (http://developer.sonymobile.com/services/flash-tool/) ?
7) After i flash my phone ,if sony release a new update can i install it via pc companion ?
😎 After unlock the bootloader,,if sony release a new update can i install it via pc companion ?
9) After i flash a new Firmware ,If i want to go back to old firmware ,can i do that ?  

10) After i flash a new Firmware ,If i want to go back to old firmware ,can i do that ?
11) After i flash a Jelly bean rom ,If i want to go back ICS (firmware 6.1.1.b.1.54 ) ,can i do that ?
12) Can i unroot ? can i locked my bootloader if i unlocked ?

[devsatan]

By following up the tutorial you must agree that I am not responsible for any damage caused to your phone . Proceed at your own risk.

1) First of all you have to unlock your bootloader by going to http://unlockbootloader.sonymobile.com/instructions

Note that this step is irreversible .You will lost all your DRM keys and after uncloking the bootloader your warranty is also void now. So please make sure that you do the things at your own risk . I am not responsible for any damage caused to your device. 

2) Second step is to root your phone.This can be done by using Flashtool.If you are on 6.1.1.B.1.10 the simply root it using flashtool.

2.1) If you have a different verison like 6.1.1.B.1.100 then First flash the kernel of 6.1.1.B.1.10 then root your phone using flashtool.

2) After you have  successfully unlocked your bootloader and root your phone ,you have to flash CMW to flash a JB rom which is a Zip file.There are lots of tutorials on internet about the same thing .So Google it  and flash it on your phone.

3) Donwload Dewswift JB port from xperia P form XDA developers . You will surely find it using google.

3) Next thing is flashing.Make sure that ICS rom is accessible. Boot the phone to ICS then place .ZIP file in sdcard then disconnect your phone.

4) Next go to recovery by simply pressing volume down key when you see the SONY logo and you are in CMW recovery .

5) WIpe cache partition, Dalvik cache and also data and system n which is in advanced menu.

6) Next choose zip form sd card option and you will see the .zip file on your sd card . Simply press the middle dot on your phone and the flashing will start.

7) After successful completion boot your phone.Note that first boot will take a while and after then you will see the homescreen .

😎 Congratlation you have just installed JB rom on your Xperia U . Happy flashing.

9) You can also check the version you are using . Simply got to Setting >About Phone>Android Version>4.1.2

Double tap on this and you would see the jelly bean logo. Thankyou.

NOTE:-

#include <Your warranty is void now>

I am not responsible for any damage caused to your phone .This is for education purposes only. Do the things at your own risk.

[anfer66]

thanks i am on 6.1.1.b.1.54  ?
their is no sd card funtion for xperia u,do you mean intenal memory ?
how to backup my current firmware ?
did you try above mention steps ? 
some tips to remmber when i do this ?,thinks i may careful ?

[devsatan]

If you are on 6.1.1.B.1.54 then for rooting you would have to flash the kernel of firmware of 6.1.1.B.1.10 using flashtool. Simply open flashtool the select the Thunder icon and then select  flashmod. Select you firmware. MAke sure that you untick all the items that are in  Wipe Column and also EXCLUDE (Partition,TA , FOTA,Baseband and System ) .

2) Then you have left with loader.sin and kernel.sin in the content column. Then click on Flash. It wiil ask you to connect your phone in flashmod mode.

3) Simply disconnect you phone from computer and switch it off. Keep pressing Volume Down key and plug the phone into computer and flashtool will start the operation. Make sure you have all the drivers for you xperia u which are in flashtool folder.

4) After successful flashing the kernel switch ON the phone and root it and install CMW into your phone .

SD card means the internal memory of your phone . In xperia u this is recognised as Sdcard0 and palce the zip file in root of your sdcard .

5) To take backup of you phone you can use the CMW feature of backup and restore which backup your full phone to Sd card .

6) Yes, I tried the steps and I am successfull in installing JB rom into my phone.

Here are some screen shots.....

And don't forget to give kudos  and to select the correct answer.

[miksa]

please tell me because i see you are using devswift's jelly bean how is camera on that rom? is it better then ics or not?does it focus slowly or normal like on Gingerbread?and how is quality in comparasion to ICS and GB?

[devsatan]

Camera is working great on this rom . I have been using this rom for last 1 month. I don't think there is any issue or bug with this rom or with camera funtionality.

Focus functionality is same as in ICS or in gingerbread with same Auto focus Function.

I would give 9/10 as I compared this rom with ICS becasue Sony stock ICS(Version 6.1.1.B.1.10) is so laggy and full of bugs. 

[devsatan]

Camera is working great on this rom . I have been using this rom for last 1 month. I don't think there is any issue or bug with this rom or with camera funtionality.

Focus functionality is same as in ICS or in gingerbread with same Auto focus Function.

I would give 9/10 as I compared this rom with ICS becasue Sony stock ICS(Version 6.1.1.B.1.10) is so laggy and full of bugs. 

Ram management is great on this rom. Battery life is good and is same as with ICS.

[anfer66]

now i am so excited to give a try,i look at xda and i find few rom what is  devswift's jelly bean rom ?

 http://forum.xda-developers.com/showthread.php?t=2284394
http://forum.xda-developers.com/showthread.php?t=2461791
http://forum.xda-developers.com/showthread.php?t=2420029

[devsatan]

The first link contains the Dewswifts rom. Download the lite verison of this rom i.e V6 

http://forum.xda-developers.com/showthread.php?t=2284394

[miksa]

i know that devswift rom dont have bugs and camera works i only asked because on ics camera work but is sooo slow to focus and i hope that is corrected in jelly bean

[devsatan]

Don't worry about the camera . It is best in jelly bean . The focus function is fast and you can point to any objet rapidly to take a picture. So, don't worry about that .Just flash it.

Note :- One thing you woult not get in Jelly bean by devswift (Only in lite version V6) is Google Apps . You have to download all these manually from Playstore . Playsotre is included  but e.g. Maps ,Gmail,You Tube these are not included in lite version.

But if you download the full version you get all these by default. But the rom is slow as compared to jelly bean lite version . So flash according to your requirements.