[Xperia Arc Android Development] rr+:
Detailed walkthru to get it on the PRO (locked BL)

I have just flashed V9 on a rooted Xperia pro with locked bootloader.

There were some questions whether it is possible here, but no answers.

Well, here is my answer with detailed walkthru for "noob"s:

(1) starting point: how to get most out of my new xperia pro?

I got my pro with German UI, firmware MK16i 4.0.2.A.0.69

Looking for improvements I found this thread, it's a "gold mine" for the pro:

http://xdaforums.com/showthread.php?t=1642480

I decided to give Xperia PLUS the first try, because JB ROMS are said to have weaker

hardware support and ICS for Xperia 2011 is oftenly regarded "clumsy" (some ROMs claim

to overcome that, maybe I will try them later on).

At first glance, Xperia PLUS perfectly matches my preferences:

- small, only most basic apps (I know what apps I want)

- recommended setup uses stock kernel ==> full hardware support (camera, HDMI, keyboard)

- optimizations for better battery

- some modifications I like

(2) rooting via DoomLord ZergRush exploit gives root with GB kernel

Reading many threads in XDA-Dev and others found "googling around",

I found out there are several options to root the Xperia pro:

(2a) downgrade to firmware 4.0.2.A.0.42 and apply DoomLord ZergRush exploit

(2b) flash MK16i 4.1.B.0.587 firmware, flash kernel 4.0.3 from xperia neo,

root "blind" w/o GUI on mobile, flash 4.04 pro kernel

(2c) unlock bootloader and flash any pre-rooted kernel

(2d) later on I discovered a procedure to root ICS firmware with some backdoor

in user data established on a rooted GB firmware: see

To install xperia plus ROM, a GingerBread kernel is needed, stock kernel is recommended.

So I decided to use (2a). It seemed to be the easiest method and is reversable (warranty ...).

It worked fine as described in details in other threads here by

- installing flashtool v0.9.10.1 on PC (Win XP)

- installing pro drivers from flashtool driver directory on PC

- flashing 4.0.2.A.0.42 firmware (found here: )

- NOT WORKING: rooting via flashtool. Always part 1 failed (I tried all variants).

I found some post saying it needs an older flashtool release

- download DooMLoRD_v4_ROOT-zergRush-busybox-su.zip and run on PC: pro is sucessfully rooted!

- download RecoverX.zip (universal CWM installer) and run on PC -> CWM installed!

After that, I did the OTA update to 4.0.2.A.0.69 (hoping it includes some kernel/baseband update), followed by a system backup in CWM.

(3) flashing xperia plus V9 and patch for pro works smoothly

I just followed the setup instructions 1 to 10 exactly, with the following differences:

- I did not flash another baseband lib: I thought kernel and baseband should match,

and assumed that flashing another baseband will not work with locked bootloader.

Am I right?

- I did mount cache and system volume after formatting (before step 7). It's not

in the install howto, but I thought without mounting, it could be difficult to

install ZIPs in system volume.

No problems encountered.

System check after 2nd boot shows:

- wifi is fine, no need to flash wifi lib-s

- hardware keyboard is working, but qwerty layout and several keys are dead

There is a keyboard thread here with the qwertz layout I need

- SuperUser app is there, libs are 3.1.2 (up-to date) -> nothing to do in step 11

- camera is working, did not try HDMI and radio so far.

- google play is working, installing some apps without any problems

(4) BUT: no root, no CWM.

After rebooting I was pleased by the minimalistic, lean setup.

I started installing my favorite tools like ROM Toolbox (pro), Link2SD, ...

and discovered: No root anymore, no CWM any more :(

Symptom is: root request is not answered, apps try infinitely or cancel via timeout.

I installed two root checker apps, both show identical behavior: they start their check,

tell me "waiting for answer" and after a while they tell me "Superuser does not answer".

Superuser is configured to display a message box for a root access request, but no

messagebox did pop up. The Superuser app itself does not get root access, and its log

stays empty (I expected some)

On a reboot, pressing repeatedly the "back" key to enter CWM, nothing happens.

Device continues its normal boot.

This is the same behavior it was with the original firmware.

(5) "root-typical settings" help to gain root access

Looking for a way to get root back, I prepared to run the Doomlord ZergRush exploit again.

Routinely checking the settings before that, I found:

Typical settings for root users are reverted to stock default.

- USB debugging is disabled (set back to "enabled")

- "install apps from other sources" is disabled (set back to "enabled")

- USB connect mode is MTC (set back to MSC)

To be sure everything is active, I rebooted.

And then - what a surprise - the superuser request message boxes are popping up!

Both root checkers assert "device is rooted". FINE! BACK IN BUSINESS!

(Has anyone an idea why these settings change back to "rooted" mode?)

(6) And how to get recovery working again?!

Recovery is still not functional.

I tried these variants without success:

- reboot and repeatedly press "back". I tried it after all following attempts

- reboot into recovery usingn function in ROM Toolbox Pro

- re-install recovery using recoverX on PC as I did before. runs w/o error msg but does not work

- re-install recovery using flashtool. But: option is greyed out :(

- install and run ROM Manager APP on device

- install/update recovery says "unsupported device"

- it claims there is no official CWM for MK10i

- I answered "yes" on question on "manual setup done"

- I tried both variants (CWM 2.x and CWM 3.x)

- ROM Manager function "boot to recovery" does not work

- reading a LOT threads around CWM&Xperia.

- learned that the key to get into it differs with device type

- learned sometimes one key press in boot sequence is sufficient, sometimes MANY key presses arfe neaded

- learned that it is not in its own partition (as I did expect) for Xperia 2011 devices

- as a consequence, installing a new ROM will usually destroy CWM 8bit the new rom might have its own)

- learned do NEVER restore a backup produced with another revovery version (!!)

- learned the patch to branch to CWL boot instead of normal boot can have problems to recognize a keypress

- learned most Xperia CWM installers do not only require root but a stock ROM (could explain my install failures)

- they replace/modify some files used during boot sequence which might not exist/function differently on other ROMs

- learned one could manually install CWM with a root file manager (hard & error prone w/o deep knowledge)

Finally it had a happy end: I found a thread discussing some patches to deal with key recognition problems,

and I decided to try that. Luckily, it was wrapped into an installer app available via google Play: X-Parts.

See http://xdaforums.com/showthread.php?p=29561187

X-Parts was able to install CWM and now I can go to recovery with any (and only one) keystroke during boot.

(7) and the German keyboard ...

Xperia PLUS comes with an american QWERTZ key binding for the hardware keyboard. I found the German one (and others) here:

http://xdaforums.com/showthread.php?t=1690889

Installing that ZIP via CWM recovery was easy.

Thanks apmartin1991!