READY FOR FLASHING
This guide should in theory make your Ultra ready for flashing custom ROMs, and with that said...
...here comes the warning: Your warranty is now voided. I am not responsible for bricked
devices, or whatever you might end up with.
ROOT ALL THE THINGS
BACKUP TA PARTITION
UNLOCKING THE BOOTLOADER
INSTALLING RECOVERY AND TWRP
FLASHING A CUSTOM ROM
BACK TO STOCK
IF YOU'RE NEW AROUND HERE AND YOU WANT TO ROOT .757, DOWNGRADE TO .532 AND ROOT, AND THEN BACKUP YOUR TA PARTITION. PROCEED TO UNLOCK YOUR BOOTLOADER, UPGRADE TO .757 AGAIN AND ROOT BY FOLLOWING THE SHORT GUIDE HERE.
ROOT ALL THE THINGS:
Thanks to @geohot, we're now able to root (almost) all the things, meaning there is now one tool for rooting. This tool doesn't touch the bootloader, so it also works on locked bootloaders. Be sure to backup your TA partition after you've rooted (in case you want to unlock the bootloader). You can find the tool here.
Note: This tool will not work on the GPe model.
Go to this thread and follow the steps.
Same procedure as with .681, so just go to this thread and follow the steps. Requires an unlocked bootloader.
Rooting .681 (first KitKat build) is pretty straight forward and requires an unlocked bootloader.
After that, just flash the kernel and then SuperSU. You can download and follow the short guide here. The kernel includes Recovery.
• Unlocked bootloader: Follow this thread.
• Locked bootloader: Follow this thread.
• Unlocked bootloader: Follow this thread.
• Use this tool to root
GPe OWNERS: DO NOT TRY TO FLASH FTFs OR OTHER "XPERIA" ROMs AND KERNELS.
YOU WILL BRICK YOUR DEVICE.
Go to this thread and follow the steps. Thanks to @blueether.
• Download and install Flashtool (if you're running Windows 8, follow this installation guide) (Jump down to "Part 2" of the guide)
• If you're having issues with driver installation, install this one.
If you have issues, or simply have no clue how to install ADB and Fastboot, install and run this.
• Download NUT's 532 firmware from here
• Flash it by following this short guide
BACKUP TA PARTITION:
The TA partition holds all your unique DRM keys, and X-Reality won't work without it (except if you're on .681 or later).
Once you lose it, you can't get it back, so back it up and upload it to your Dropbox or something. So how do you backup your TA partition?
• Download this tiny tool on your computer and run it.
Here's a video tutorial by @hamdogg
CHANGE CDA (OLD):
This step is no longer necessary.
• Install a file explorer from the Play Store. I recommend Solid Explorer or ES File Explorer.
• Navigate to /system and open build.prop
• Change your CDA to: C6833_1275-8026 (there are three different places this has to be changed.
Just take your time and try to find something that resembles the CDA code above.
• Next you'll want to find "ro.somc.customerid" and change it to 436
• Next you'll want to find "ro.semc.version.cust_revision" and change it to R11A
• Now reboot your device
• The OTA update should arrive now. If it doesn't, go to "Update Center" (app) and manually refresh.
• Update to 257
• The root app (i'm not sure what app it installs) might be gone, so just install
SuperSU from the Play Store if it's not in your app drawer anymore. Update binaries and choose "Normal".
UNLOCKING THE BOOTLOADER:
This may wipe your phone, so backup your stuff
• Go to Sony's dev site
• Request the unlock key and check your mail straight away. Email is quick these days.
• Open Flashtool on your computer (yes, the one you installed earlier)
• Click the "BLU" icon
• Follow the steps and enter your unlock key
INSTALLING RECOVERY AND TWRP:
• Just run this tool on your computer.
• Boot into Recovery (POWER + VOL UP)and take a NAND backup ASAP.
It'll "save your life" (or time) when you're soft bricking your Ultra.
FLASHING A CUSTOM ROM:
• Find a ROM
• Move the ROM (and gapps if it is required) to a folder on your Ultra and remember where you put them
• You'll see that you'll need to flash a "boot.img" before you flash anything, so download this
• Now go to this thread and download QuickIMG and follow the short guide
• Flash the boot.img
• Now unplug from the computer and enter Recovery by pressing the Power button.
Once you see the green LED, push and hold VOL UP. If you fail, just press and hold POWER + VOL UP until you
notice some rapid vibrations. Now try again.
• Once you're in Recovery it's the usual stuff. Flash the ROM and gapps and wipe data/cache/dalvik etc.
BACK TO STOCK:
So you have to send your Ultra to a service center and you want to get it back to 100% stock.
Be sure to be on a STOCK kernel before restoring the TA partition or re-locking the bootloader.
• Restore your TA partition using the tool from the "Backup TA Partition" part of this guide.
• If your bootloader hasn't been locked by the TA tool, use Flashtool and press the BLU button and choose "Relock".
• You may not be able to boot now if you're on a custom ROM, so fire up Flashtool again and flash a stock ROM.
BLINKING RED LED:
So, you locked it while on a custom kernel, and all you get now is a blinking red LED above your screen.
Simply unlock the bootloader in Flashtool again, and it'll work again.
You should now be back on stock, un-rooted and with TA and bootloader in place. If you're back on stock,
but the bootloader is still unlocked, get back to 532, root, lock the bootloader, and then flash a FTF in Flashtool again.
You've ended in a bootloop and you have no idea what to do. A bootloop is when the boot animation is looping, and you're stuck.
We'll start out easy and go harder as we go down the list.
• [SAFE] Boot into Recovery and wipe cache and go to "Advanced" and wipe Dalvik. Reboot and see if it boots now.
• [SAFE] Boot into Recovery and re-flash the ROM and see if that does the job
• [WIPE] Boot into Recovery and wipe data (this will wipe everything) and reboot
• [WIPE] Boot into Recovery and flash a different ROM (wipe data after flash) and reboot
• [LAST RESORT] Fire up Flashtool and flash a stock FTF and get a new hobby
You downgraded from 290 or later, didn't you? Well, you'll have to update again or flash [NUT]'s .532 build.
- @herogjan - The mighty discoverer of the OTA root method
- @krabappel2548 - The Belgian Don (guides, ROMs etc.)
- @RyokoN - ROOT Wizard
- @hamdogg - Bootloader help
- @fastest83 - Achievement unlocked [1/168]
- @sfagundes - For the GPe root guide
- @hamdogg - For helping people and for the video(s)
- [FONT=Arial @blueether - For helping an incredible amount of people around here[/FONT]