Database Develop

[Q] Bootloader and Rooting - which one does what?

Hello,
I just got my new Xperia Z having used my ancient Iphone 1G for the last 4 years and I have no experience with Android and anything related to it what so ever. I've spent the last 2 days tirelessly working my way through various forums, guides, wikis to get an idea what I'm dealing with here and where to start, but there's an important decision that I could really use your thoughts and tips on.
After reading up on it, I decided I want to root my phone and this seems to be somehow connected to unlocking the bootloader and this is where I'm worried. I read the guide on how to unlock the bootloader and the warning about losing DRM Keys and the consequences of this scared me away from it. Now I'm left wondering, and this is my actual question here:
What is the difference between unlocking the bootloader and rooting my phone and simply rooting without unlocking the bootloader?
And in case the things I want to do are only available with an unlocked bootloader: how damaging is it to lose DRM keys and therefore the bravia engine and gracenote? What made you decided for or against unlocking the bootloader?
Thanks!

Hi,
maybe I can help you.
Bootloader is like the BIOS of a PC. It checks everything at start up.
Locked Bootloader only allows to run the Stock FW and in this case the DRM-Keys are working (everything is checked and safe)
Unlock the Bootloader means you were able to install an modified / other FW and then you loose the DRM-Keys (the manufacturer hasn´t checked the FW and it is in the eyes of an manufacturer "not safe". You will also loose your warranty.
If you unlock the bootloader Root is always possible as I know.
In this case the system is not from the manufacturer and unofficial modification could be done to the system. Normally all modified Systems have Root access. So you were able to do things that the manufacturer has normally not allowed. Modify system files or something like that. Also it could be possible to copy for example a downloaded and payed movie to another device. This is why you were not able to download a movie on the Play Store if you have root. On a locked bootloader the FW (system) does not give you the possibility to copy the movie to an other device and everything is "safe" (from the view of companies). No illegal copies are possible. (DRM-Keys)
Since some days Root is also possible on a locked bootloader.
The bootloader is checking the status (locked) .. then checking the FW (stock) ... DRM-Keys still valid.
But due to the root access you were also able to modify system files and apps can recognize that you have root access. So you can still use the bravia engine for example (DRM-Keys are ok). But the Google Play Store will still recognize that you have root and will not let you download movies.
This is my experience with Root ... If something is not correct, please correct me

UserX10 said:
Hi,
maybe I can help you.
Bootloader is like the BIOS of a PC. It checks everything at start up.
Locked Bootloader only allows to run the Stock FW and in this case the DRM-Keys are working (everything is checked and safe)
Unlock the Bootloader means you were able to install an modified / other FW and then you loose the DRM-Keys (the manufacturer hasn´t checked the FW and it is in the eyes of an manufacturer "not safe". You will also loose your warranty.
If you unlock the bootloader Root is always possible as I know.
In this case the system is not from the manufacturer and unofficial modification could be done to the system. Normally all modified Systems have Root access. So you were able to do things that the manufacturer has normally not allowed. Modify system files or something like that. Also it could be possible to copy for example a downloaded and payed movie to another device. This is why you were not able to download a movie on the Play Store if you have root. On a locked bootloader the FW (system) does not give you the possibility to copy the movie to an other device and everything is "safe" (from the view of companies). No illegal copies are possible. (DRM-Keys)
Since some days Root is also possible on a locked bootloader.
The bootloader is checking the status (locked) .. then checking the FW (stock) ... DRM-Keys still valid.
But due to the root access you were also able to modify system files and apps can recognize that you have root access. So you can still use the bravia engine for example (DRM-Keys are ok). But the Google Play Store will still recognize that you have root and will not let you download movies.
This is my experience with Root ... If something is not correct, please correct me
Click to expand...
Click to collapse
Hi and thanks a lot for your reply, helped me understand the difference of both better!
If I only root but do not unlock my bootloader will I be able to do anything other than using custom firmware (ROMs)? Will I be able to install Apps that require root or install custom modification like the ones offered on this forum that need to be "flashed in recovery" if I only root not unlock my bootloader?
Also, still looking for some pros and cons (my second question in the original post).
Appreciate all your help!

root will give you access to recovery (in time - still in development) and you can install apps that require root access
custom mods - yes you can install them via recovery and some can be installed with root access and without recovery
if u unlock bootloader you will lose bravia engine not sure bout gracenote as i dont use it
you can check this thread http://forum.xda-developers.com/showthread.php?t=2154310 too see what have people wrote bout
rooting with unlocked bootloader

The main thing pointing me towards unlocking bootloader (I'm already rooted on locked bootloader) is being able to install kernels and major roms.
For example, you could flash Doomlords kernel and over clock the processor a bit, but you could also reduce power and save battery
The major roms I speak of are the ones that are kinda cross device: CyanogenMod and Paranoid Android to name 2. CM is based on pure android, no Sony changes so we can't flash that on locked bootloaders as it requires changing kernel. PA is same.
As for the downsides. I'm not too bothered about DRM keys. I use Spotify for music so don't think I need gracenote. Never watched a movie on my phone. BE2 isn't my cup of tea... Over saturates everything.
I'm going to look into DRM keys more tomorrow, but if someone can correct anything I've written then please do
Not being able to restore via Sony tools... Isn't that bad as you're going to be using flash tool a lot so you'll be used to that. Just keep a generic stick firmware .ftf around in case something goes horrendously wrong (usually recovery backup is enough I think).
Sent from my C6603 using Tapatalk 2

Nice thread, I had this question too
It's my first android and I guess I should unlock the bootloader and then root, this way I won't have to wipe my data later when I decide to try cyanogenmod or something else?
Also what happens if sony release 4.2? Will I lose my bootloader unlock and root?

Al Gore said:
Nice thread, I had this question too
It's my first android and I guess I should unlock the bootloader and then root, this way I won't have to wipe my data later when I decide to try cyanogenmod or something else?
Also what happens if sony release 4.2? Will I lose my bootloader unlock and root?
Click to expand...
Click to collapse
I would say root without unlock for now.
When you want to try cyanogenmod or others. Just backup everything using titanium backup and then u can restore after unlocking.
Rooting with a locked bootloader means sony are not aware your bootloader is unlocked
Sent from my C6603 using xda premium

Thanks for all your replies, helped me out a ton!
I think Im gonna root without unlocking bootloader for now to get my feet wet and get a grasp of it's capabilities and limits. Can always restore the phone if I screw up and can always unlock bootloader later if I need it.

Al Gore said:
Nice thread, I had this question too
It's my first android and I guess I should unlock the bootloader and then root, this way I won't have to wipe my data later when I decide to try cyanogenmod or something else?
Also what happens if sony release 4.2? Will I lose my bootloader unlock and root?
Click to expand...
Click to collapse
If you unlock Bootloader, you shouldn't update from Sony. Since you've (hypothetically) already unlocked, you already have 4.2 avaliable from FXP and if you really want the Sony Update maybe you could flash it via flash tool. Bootloader unlock will never be lost (until someone can create an explicit relock file, but customs roms won't relock it). Root maybe lost if you flash a rom without it but you should be able to get it back easy.
With locked bootloader, we have to wait for Sony to bring 4.2 as we can't access the kernel, but we retain the ability to use the official updates. If we're rooted and we update, we are no longer rooted and we may be unable to use the same exploit.
Sent from my C6603 using Tapatalk 2

[Q] Relock the Bootloader and others

ZR is my very first Android phone, so basically I know nothing about Android.
I unlocked the bootloader couple of weeks ago following the official Sony instructions in order to flash the stock Taiwan ROM (cause China's ROM doesn't support Google service). But now I found that I cannot update via Sony. More importantly, it's actually not necessary to unlock the bootloader for flashing ROM and/or get root privilege. So I'm desperately seeking the way to relock the bootloader.
I found some guy talking about flashing a small file called Xperia_Relock_bootloader.ftf. But he said that it was only for old models. Anybody here can help? Thanks in advance!
P.S. They said that after unlocking the boot loader, Bravia Engine and TrackID service will gone. But I have both working still. Weird. Does that mean I can backup my TA partition still?

[Q]s-off vs unlocked bootloader

What are the benefits of s-off over just unlocked boot loader

by unlocking bootloader u can root ur device, can flash custom recovery & custom roms on ur android device....

shad0wboss said:
What are the benefits of s-off over just unlocked boot loader
Click to expand...
Click to collapse
I don't have this particular device but I will tell you the general information and you can work with that.
About Bootloader(Unlocked Bootloader):
The bootloader is like a BIOS of your PC. It is the thing that is powered on and verifies all hardware and is responsible for making connection with the hardware. This can either be unlocked or locked. When you have a locked bootloader you can still root (if an exploit is available). You can even install a recovery or custom rom if an exploit is available (like BUMP was). What was it doing? Signing the images for your so the locked bootloader will think it is the OEM image. In most of the cases this is not so happy. Usually you can't flash a recovery or a custom rom or stuff like that with a locked bootloader. Some OEM's provide websites to unlock the bootloader (with the cost of losing warranty; well not really). This is the case of Sony, HTC. Some Oem's don't provide this.
About S-off:
What does S-off mean? Security off. Your device will come with S-ON always unless it's a Dev edition (correct me if I am wrong). What this does is it doesn't leave you to do very advanced operations related to the EMMC (the Nand chip). You can't flash a bootloader you wish or stuff like that. Update radio partition. In some cases system partition is also secured so you can't flash a custom ROM. By S-off you get full control of your device but if a mistakes occurs you will end up with a hard-bricked device.
Peace. Hope you understood.

neutrondev said:
I don't have this particular device but I will tell you the general information and you can work with that.
About Bootloader(Unlocked Bootloader):
The bootloader is like a BIOS of your PC. It is the thing that is powered on and verifies all hardware and is responsible for making connection with the hardware. This can either be unlocked or locked. When you have a locked bootloader you can still root (if an exploit is available). You can even install a recovery or custom rom if an exploit is available (like BUMP was). What was it doing? Signing the images for your so the locked bootloader will think it is the OEM image. In most of the cases this is not so happy. Usually you can't flash a recovery or a custom rom or stuff like that with a locked bootloader. Some OEM's provide websites to unlock the bootloader (with the cost of losing warranty; well not really). This is the case of Sony, HTC. Some Oem's don't provide this.
About S-off:
What does S-off mean? Security off. Your device will come with S-ON always unless it's a Dev edition (correct me if I am wrong). What this does is it doesn't leave you to do very advanced operations related to the EMMC (the Nand chip). You can't flash a bootloader you wish or stuff like that. Update radio partition. In some cases system partition is also secured so you can't flash a custom ROM. By S-off you get full control of your device but if a mistakes occurs you will end up with a hard-bricked device.
Peace. Hope you understood.
Click to expand...
Click to collapse
Thanks!
Things is, i was more concerned about the practical info about this device specifically because I have read that with just bootloader unlocked, the roms that i'll be able to flash will only change the visual and not so much with the kernel etc. I don't understand why people would choose to S-OFF for this device for other than just relocking the bootloader.

shad0wboss said:
Thanks!
Things is, i was more concerned about the practical info about this device specifically because I have read that with just bootloader unlocked, the roms that i'll be able to flash will only change the visual and not so much with the kernel etc. I don't understand why people would choose to S-OFF for this device for other than just relocking the bootloader.
Click to expand...
Click to collapse
Sorry I can't really help you with that information I don't know if you can flash a Custom kernel with S-on. Never had a sony. Someone will help you out soon.I hope.

i'l bump this question up then :/

I think S-off is a term unique to HTC devices. Its the equivalent of an unlocked bootloader

tonysunshine said:
I think S-off is a term unique to HTC devices. Its the equivalent of an unlocked bootloader
Click to expand...
Click to collapse
yes but nth to lose on HTC except warranty (still subject to which svc ctr tho) while on Sony, losing DRM keys (w/o backup) are like downgrading ur phone full capabilities.

monx® said:
yes but nth to lose on HTC except warranty (still subject to which svc ctr tho) while on Sony, losing DRM keys (w/o backup) are like downgrading ur phone full capabilities.
Click to expand...
Click to collapse
Is there a way to root without losing keys? I have Z3 LTE D6603 atm.
Sorry if it's a dumb question, I'm new here. And also new to sony rooting, which seems much more complex than my old Nexus 5 lol

tonysunshine said:
I think S-off is a term unique to HTC devices. Its the equivalent of an unlocked bootloader
Click to expand...
Click to collapse
Not really, you can flash kernels, roms ( aosp roms etc ) with unlocked bootloader, S-off gives you other stuff like changing mid, cid, sim unlock, downgrading/upgrading bootloader, converting to full GPE or dev edition, unlocking bootloader without need of HTC, flashing splash image, custom bootloaders, even converting to Windows ( if available of course ) locking it instead of re-locking it, restoring it to full stock state ( which is not possible without S-off ), simply put your device has no limits with S-off on HTC.
Anyway S-off isn't really needed unless you care for the things above ( if Sony even has S-off ), Sony has poor development so S-off isn't even needed or unlocking bootloader since basically all you get is aosp roms, stock alike roms are flashable with locked bootloader as far as I remember.
Sent from my HTC One M8 using Tapatalk

UNLOCKING BOOTLOADER : What i'm going to lose.

Guys, i've been using many mainstream brands like HTC, Sony, Samsung, etc but im newb to Huawei.
For Sony device, im going to lose DRM keys for good after unlocking BL (not to mention backup TA) and many other features & functions like screen mirroring & camera quality degrade.
For Samsung, the well known Knox.
Im about to unlock my P9Plus but by reading this, quoted frm Huawei bootloader unlocking page, im abit scared of losing Leica image processing for instance.
4．Some functions will no longer work after you unlock the bootloader. For example, you will no longer be able to use Digital Rights Management (DRM) keys and digital content that you have purchased. Upgrading software using Firmware Over-The-Air (FOTA) or a microSD card may fail or your device may not function properly after upgrading.
Click to expand...
Click to collapse
Can anyone shed some lights?

I asked this before i unlocked my bootloader, as my previous phone was also a Sony.
I was told nothing would be lost, and from what i can tell, the phone still seems the same as it was out of box.
If you do notice anything, please let me know as well.
I haven't received any OTA update, but i can always download and update via SD-Card if i require.
Haven't tried playing any videos on the phone, besides ones that I've taken myself, but nothing i have contains DRM protection so I don't see any issues there anyway.

This is my 3rd Huawei Device after the P8 & Mate 8.
On all the devices I didn't notice any changes after unlocking.

how about screen mirroring & netflix/iflix HD. if im not mistaken netflix wont play HD movies if DRM is absent on device.

Hi, i wan't to temporary unlock BL only to de-brand my P9+. So i'll relock it after the operations. In that scenario, what happens to my warranty? If now I check the warranty status with Huawei services, i receive a message that the phone i regularly under warrenty until xx/xx/xxxx. If i unlock BL that message remains or will change in something as "NO WARRANTY..."
Thanks

stalvatero said:
Hi, i wan't to temporary unlock BL only to de-brand my P9+. So i'll relock it after the operations. In that scenario, what happens to my warranty? If now I check the warranty status with Huawei services, i receive a message that the phone i regularly under warrenty until xx/xx/xxxx. If i unlock BL that message remains or will change in something as "NO WARRANTY..."
Thanks
Click to expand...
Click to collapse
If you somehow already have the bootloader unlock code (e.g. from DCUnlocker), then the warranty displayed on the website will not void, at least on my Singapore's VIE-L29C636. But I am not sure through if you get the unlock code via the official EMUI website. Your bootloader's state will become "unlocked", and if you do relock your bootloader, it will show "relocked" instead of "locked". Read my post here to revert it back to "locked" state.

everybody MIA :laugh:
Sent from my Huawei P9 Plus using XDA Labs

[REQUEST] DRM info after relocking bootloader

From the title: I'm kindly requesting to check DRM status (DRM Info app here) after unlocking bootloader and after relocking the bootloader.
If possible with a screenshot otherwise I'm interested in knowing if Widevide DRM Level goes back to L1 after relocking and how System ID changes with L3 and L1.
Furthermore t's useful knowing if you also flashed a custom rom and/or blew Knox Fuse in some other way.
Disclaimer: do not unlock your bootloader just to do this check. This request is meant for people who already have bootloader unlocked by their own means.
There is a screenshot example attached to this thread, stock locked A71 never before unlocked.

You keep your DRM keys when unlocking bootloader on A71, so Widevine stays at L1.
No TWRP installed, only magisk.

oh, that's actually really good news.
My previews experience with Widevide DRM was a permanent keys loss.
Thank Samsung for this approach.
Should I be warry of some particular step into installing magisk on A71 ?

ban.codrut said:
Should I be warry of some particular step into installing magisk on A71 ?
Click to expand...
Click to collapse
Not really. I rooted by mixing magisk into android and then flashing it with odin. There are some tutorials on youtube, showing how it's done.