[Sony Xperia S, Acro S, Ion] hitman-xda:
This is a guide for XPERIA ACRO S (other xperia users can also refer needed information)

[Below procedure looks lendy, but you'll just need max 30 minutes if you have every downloaded file.]

I make this guide for noobs as there weren't such guide (even for my first time of flashing ROM I didn't get any such guide, so I decided to make one)

This Guide is especially for flashing BPaul's 5.1.1 ROMs (B3||B2||B1)

To Flash Different Versions Of BPaul's ROM follow Respective Guide:

Beta1 threads POST #13

Beta2 same thread

Beta3 threads POST #40

So here I'm giving detail process to install Bpaul's 5.1.1 with every links needed.

we are going to take below steps;

1. unlocking Bootloader

2. flashing kernel with recoveries

3. backing up stock ROM

4. installing BPaul's 5.1.1

Special Thanks;

[MENTION=4074348]BPaul[/MENTION] (for awesome ROM)

[MENTION=2720279]cobrato[/MENTION] (for stock kernel)

[MENTION=5772029]jajb[/MENTION] (for gapps)

-Here we START-

Note: Before Unlocking Bootloader, I suggest you to Backup your TA Partition. (Trim Area) IF in future something goes wrong with network signal related issues or bootloader issue, you could restore this backup. TA Partition can be backed-up ONLY before unlocking bootloader. To backup TA follow this "Guide" and after you could below steps. Also your phone needs to be Rooted to backup TA, if your phone isn't rooted, follow this "Guide"

*_UNLOCKING BOOTLOADER_*

(unlocking bootloader will erase everything on your phone, i suggest you to take backup of your data)

First check weather you can unlock your bootloader. To do so type *#*#7378423#*#* in dialer and find bootloader unlocked status.

IF bootloader unlock allowed = YES (you can unlock)

IF bootloader unlock allowed = NO (you can't unlock)

IF bootloader unlocked = YES (already unlocked)

Then you need to take unlocking code from official Sony website (link below)

LINK1 Unlocking Bootloader

after clicking on above link, on the page just scroll down

1.select your device

2.provide your IMEI

3.you'll get unlock code (save it properly)

Next you need to download minimal adb and fastboot (link below)

LINK1 Miniamal ADB and Fastboot

install it to your computer.

Now we have to connect phone in fastboot mode, follow below steps

1.Turn on usb debugging mode.

(setting > developer option > usb debugging)

2.Turn Off your Xperia Acro S

3.Press and Hold volume up button and then connect usb to computer.

(If you see Blue LED of phone, then everything is going right)

(Let your computer install essential fastboot drivers)

[If blue LED disappears after some seconds and phone starts charging, that means your PC isn't installing fastboot drivers. In such situation REFER Q&A thread POST #4 ]

Now open minimal adb and fastboot (we installed previously)

Type below command

-fastboot devices

-fastboot -i 0x0fce oem unlock 0x(your unlock code without this brackets)

-fastboot reboot

DONE

(Now you have successfully unlocked your bootloader)

[ To check that if you have succeeded in unlocking bootloader type *#*#7378423#*#* in dialer and find bootloader unlock status.

ALSO you'll notice that your phone is factory resetted]

*_FLASHING KERNEL WITH RECOVERY'S_*

As you have STOCK ROM, you need to flash STOCK KERNEL with recoveries (link below)

LINK1 Stock Kernel

-The above kernel cantain CWM as well as TWRP

After opening above link, download respective kernel

Save the above downloaded kernel to fastboot folder on your computer.

-Get into fastboot mode and connect to computer.

(Press and Hold volume up button and then connect usb to computer).

Now open minimal adb and fastboot (we installed previosly)

Type below command

-fastboot devices

-fastboot flash boot kernel_62B196_acroS.elf

-fastboot reboot

DONE

(Now you have successfully flashed kernel with recovery)

*_BACKINGUP STOCK ROM_*

As you have successfully flashed kernel with recoverys, its easy to take a full backup of your system.

To enter into recovery follow below steps

1.To get into CWM reboot your phone, press volume up key for few times when the magenta LED appears.

(To navigate use volume buttons, for selecting use power button)

2.To get into TWRP reboot your phone and tap the screen for few times when the magenta LED appears.

3.Select Backup.

(let the process finish)

I SUGGEST TO TAKE BACKUP FROM BOTH RECOVERY'S

DONE

(Now you have successfully Backed-up your ROM)

Flashing BPaul's Beta2 ROM works ONLY IF YOUR PHONE HAS Beta1 ROM installed. If you don't have Beta1 installed, first of all install it. . If your phone has Beta 1, ignore this and carry on.

*_FLASHING ROM BPaul's 5.1.1_Beta 2 over Beta 1*

For Flashing This ROM your phone (Xperia Acro S) needs to be rooted if your not rooted, follow this "Guide" Also USB Debugging in developers option should be enabled.

A] Download ROM BPaul's 5.1.1 Beta 2 (link below)

LINK1 BPaul's B2

C] Download below minimal GApps for 5.1.1 and copy it to your sdcard/ext_sdcard(link below)

LINK1 GApps for 5.1.1

1.Download fota kernel with cwm recovery (link below)

LINK1 Fota Kernel

2.Copy above downloaded kernel + rom to internal storage of your phone

3.Open minimal adb and fastboot

Type below command;

-adb shell

-su

(confirm popup su request from your phone)

-dd if=/sdcard/hikari-fota_CWM.img of=/dev/block/mmcblk0p11

Now you need to enter into recovery. To do so, restart your phone in recovery mode.

1.Wipe system + factory reset

2.Install zip from sdcard/ext_sdcard

(select beta-hikari...... rom)

3.Wipe cache + dalvic cache

4.Again install zip from sdcard/ext_sdcard

(select 5.1.1 gapps)

5.Again wipe cache+ dalvic cache

6.Reboot

For the first time it can take a looooong time to boot up. So just don't worry.

DONE

(You have successfully installed BPaul's 5.1.1)

OPTIONAL:

For rooting this ROM, just download SuperSU, save it to your phone and install it manually with recovery. (link below)

LINK1 SuperSU

If you found above post easy and helpful, you could donate/buy me a cup of COFFEE or even a BEER!

(I'll be there for you as a online support any time), just click HERE!

(You need to have a PayPal account, If you don't have, then click HERE and just create one individual account, it's simple)

Regards,

hitman-xda