Quick question re: root/ta/bl etc on .290

djyoshii said:

I'll try and keep this short and to the point.
Currently running stock .290 firmware and wanting to root it, preferably without flashing a pre-rooted firmware, and without losing DRM keys.

Now if i want to root it according to this thread, i will need to unlock the Bootloader first:
"You'll have to unlock the bootloader if you want to root the .290 firmware (Android 4.3)."
and then root it via this, before i can run TA Backup to backup my DRM keys

What I'm confused about though, is that once the Bootloader is unlocked I lose my DRM Keys (as per this thread, and many other comments)
"The TA partition contains all your DRM keys for the Bravia/X-Reality Engine.
The first time you mess with your phone by unlocking the bootloader, these DRM keys will be deleted!"

The general consensus with regards to the proper order is:

1. Root
2. TA backup
3. Unlock bootloader

However for .290 it seems to be:

1. Unlock bootloader
2. Root
3. TA backup (if there is even anything left to backup?)

I guess what I'm wondering is if there is anyway to root .290 directly without first unlocking the Bootloader (and thus losing my DRM Keys), and without flashing pre-rooted firmware?
Or do i have this completely wrong, and by unlocking my Bootloader first, I won't lose my DRM Keys (contrary to what the linked thread above says)?

Thanks!

Click to expand...

Click to collapse

No.

You need to downgrade to 532 root, backup ta, unlock bootloader then update.

Sent from my C6833 using XDA Premium 4 mobile app

djyoshii said:

Seems I'm really left with no option then.

In that case, are DRM keys linked to the hardware or firmware? In other words, by flashing the pre-rooted firmware will i still keep my original DRM keys? Or will I have new DRM keys, belonging/linked to said pre-rooted firmware?

Click to expand...

Click to collapse

AFAIK, it's only connected to xreality and a couple of other bits. More importantly it does have an effect on some streaming apps like netflix which will only work with drm. Think there may be a workaround for that on xda somewhere.

Also, if you lose drm and cannot restore the ta partition in event of breakage, then warranty is void.

Worth backing up I'd say if only for warranty purposes.

Sent from my C6833 using XDA Premium 4 mobile app

Like Spyder says, downgrade to 532 with Flashtool (no root or anything is needed), root it (it's very simple), backup TA (even simpler), unlock your bootloader, update to 290 again and root it (it's pretty simple with an unlocked bootloader).

If you regret it all and you want to re-lock the bootloader, be sure to be on a stock ROM with stock kernel and restore TA with the same tool you used to back it up with. This will also re-lock the bootloader. If you re-lock it on a custom kernel, your Ultra will not function. It will not reboot, and all you'll be left with is a blinking red LED over the screen. IF this happens, be sure to unlock the bootloader again, and it'll boot normally again.

You only have to backup the TA partition once, so if you choose to restore it and you want to unlock the bootloader yet again down the road, then just unlock it. You have the DRM keys, so you're safe. Be sure to back them up in the cloud too (Drive, Dropbox etc.) in case your computer crashes or you simply forget the DRM keys are there.

I wrote a guide on all this stuff, so take a look at it here.

You'll need to follow:

- Downgrading
- Rooting
- Backup TA Partition
- Unlocking the bootloader

After that, just download a 290 FTF and repeat step one (downgrading, but only with 290). Then when you're on 290, follow the guide you've already found. You can also flash Recovery/TWRP by following the short "Recovery and TWRP" section.

Good luck!