[Xperia Arc Android Development] DooMLoRD:
hey guys since jerpelea has already got the custom kernels working, it will just be a matter of time before we see custom ROMs...

i am making this thread so as to answer the many questions that users are having on how to get back to stock when testing custom kernels / custom roms...

[--> WARNING <--]

PLEASE READ THE COMPLETE POST (1ST & 2ND) BEFORE U DO ANYTHING

I AM NOT RESPONSIBLE IF UR DEVICE GETS BRICKED BECAUSE U DID NOT READ THE WHOLE THING PROPERLY / U HAD SOME TYPO WHILE EXECUTING THE COMMANDS

MAKE SURE THAT UR

PHONE BATTERY IS FAIRLY CHARGED

(> 50%) BEFORE DOING ANY FLASHING AND THAT UR

PC HAS A UPS BACKUP

(BECAUSE IF FLASHING IS INTERRUPTED THEN IT CAN HAVE SERIOUS CONSEQUENCES)

[ BEFORE U BEGIN ]

Requirements:

Flashtool (it is advisable to use latest version)

Fastboot files

Stock Firmware FTF package

[OPTIONAL] PreRooted system.img files

7zip

How to use FlashTool:

FLASHTOOL GUIDE - HOW TO for n00bies

this was posted in X10 section but is even relevant for Arc/Play/Neo users

How to use FastBoot:

[Newbie Guide] adb/fastboot/bootloader/android 101

[ FLASHING CUSTOM KERNEL/ROM ]

Flashing Custom Kernel (boot.img):

this WILL NOT WIPE ur data

the custom kernel will be provided as boot.img file

just copy this file to fastboot folder

just power down device and get into FASTBOOT MODE (LED notification turns BLUE) with usb-cable connected to PC

once u are in fastboot mode open command prompt and navigate to the folder containing fastboot files then just use the following command to flash custom kernel:

fastboot flash boot boot.img

once flashing is complete you will get a prompt on pc saying that everything is ok

now just unplug ur device and u are on the custom kernel

Flashing Custom ROM/SYSTEM (system.img):

this WILL NOT WIPE ur data, it will only wipe ur /system partition

the custom ROM/system will be provided as system.img file

just copy this file to fastboot folder

just power down device and get into FASTBOOT MODE (LED notification turns BLUE) with usb-cable connected to PC

once u are in fastboot mode open command prompt and navigate to the folder containing fastboot files then just use the following command to flash custom ROM/system:

fastboot flash system system.img

once flashing is complete you will get a prompt on pc saying that everything is ok

now just unplug ur device and u on custom rom/system

[ GET BACK TO STOCK ]

jerpelea has posted an unbrick (softbrick) package in the FreeXperia project thread... details on how to use it can be found in Post #2 of this thread...

Following is much more generic information which can be applicable to any FW/ROM/Kernel

How to get back to Stock Firmware (FW):

this will get u back to COMPLETE STOCK SETTINGS

ALL ur data WILL BE WIPED

u will get back to stock kernel

u will get back to stock ROM/system

ur SDCARD data WILL NOT BE affected

you will need stock FTF package

get ur device into FLASH MODE (LED notification turns Green)

use flashtool to flash stock FTF package

for details refer to the above FlashTool guide

How to get back to Stock Kernel (boot.img / kernel.sin):

this WILL NOT WIPE ur data

using 7zip extract the FTF package to some directory

you will get many files with extension .sin

we are interested in the kernel.sin file, which is the stock kernel

just copy this file to fastboot folder

now for getting back to stock kernel just power down device and get into FASTBOOT MODE (LED notification turns BLUE) with usb-cable connected to PC

once u are in fastboot mode open command prompt and navigate to the folder containing fastboot files then just use the following command to flash stock kernel:

fastboot flash boot kernel.sin

once flashing is complete you will get a prompt on pc saying that everything is ok

now just unplug ur device and u are back to stock kernel

How to get back to Stock ROM (system.img / system.sin):

OPTION - 1 : stock unrooted system

this WILL NOT WIPE ur data, it will only wipe ur /system partition

using 7zip extract the FTF package to some directory

you will get many files with extension .sin

we are interested in the system.sin file, which is the stock rom/system

just copy this file to fastboot folder

now for getting back to stock system/ROM just power down device and get into FASTBOOT MODE (LED notification turns BLUE) with usb-cable connected to PC

once u are in fastboot mode open command prompt and navigate to the folder containing fastboot files then just use the following command to flash stock ROM/system:

fastboot flash system system.sin

once flashing is complete you will get a prompt on pc saying that everything is ok

now just unplug ur device and u are back to stock rom/system

OPTION - 2 : stock PreRooted system

this WILL NOT WIPE ur data, it will only wipe ur /system partition

use the prerooted system.img u downloaded from above links

just copy this file to fastboot folder

now for getting back to stock prerooted system/ROM just power down device and get into FASTBOOT MODE (LED notification turns BLUE) with usb-cable connected to PC

once u are in fastboot mode open command prompt and navigate to the folder containing fastboot files then just use the following command to flash stock ROM/system:

fastboot flash system system.img

once flashing is complete you will get a prompt on pc saying that everything is ok

now just unplug ur device and u are back to stock rom/system

[ TROUBLESHOOTING ]

sometimes u may run into problems after flashing back from custom system.img to stock system.img, like apps & core system crashes/force closes

if u face such problems then it is advisable to WIPE ur /data parition

this WILL WIPE ur data (apps, settings), ur SDCARD DATA WONT BE AFFECTED

just power down device and get into FASTBOOT MODE (LED notification turns BLUE) with usb-cable connected to PC

once u are in fastboot mode open command prompt and navigate to the folder containing fastboot files then just use the following command to wipe /data partition:

fastboot erase userdata

once flashing is complete you will get a prompt on pc saying that everything is ok

now just unplug ur device and the problems should be sorted out

if u still are facing problems just flash back to Stock Firmware using FLASHTOOL

[ FINAL THOUGHTS ]

I hope this answers most of ur questions...

in case of specific queries about flashtool/fastboot or prerooted images ask in THOSE SPECIFIC threads... if u have any queries other than that [RELATED TO THIS THREAD ;) ] u can post ur questions here...

PLEASE DONT FILL UP DEV THREADS WILL REDUNDANT QUESTIONS