Database Users

locked bootloaders

Just a quick question. I see quite a few posts asking rom devs to support locked bootloaders. My question is why would someone want a locked bootloader? I have had my x10 since they came available in usa and unlocked it the day I found out it can be unlocked. I am just trying to understand how a locked bootloader is fucntional in what we do. But I probably reflash my phone once or twice a week.

[Q] OEM unlock on Note 4?

(my browser spazzed and I lost my last post if it shows up as a double ignore the other one!)
I'm new to Android and finding it confusing so thanks for the help so far!
I have a 910F Note 4 on Lollipop and want to root it to get rid of bloatware and possibly stop ads (if I can convince myself it's ethical) btu I *may* want to custom ROM it later.
So far your help and my reading have taught me this:
-- I can root using chainfire in order to get rid of bloat and block ads
-- If after rooting I later want a custom ROM or Xposed I'll need to get custom recovery in which case I'll be able to add CWM or TWRP later to my rooted phone
Assuming the above are true (if not please tell me!!) my question is this:
What on earth is oem unlock/bootloader unlock? In my reading I've come across people talking about this and it wiping the phone. I can't find an easy answer online. If I root +/- do CWM/TWRP will that automatically do OEM unlock or are they different things? Is bootloader unlock a different thing too? I'm confused! Will I need to root AND custom recovery AND oem unlock AND unlock bootloader?
Thanks in advance!!!

Some devices come with a locked bootloader, where you may be able to root the device via an exploit, but you can't change lower level software (ie kernel and/or recovery)... unless there is an unlock method for the bootloader.
The devices that do have a locked bootloader can be locked by the manufacturer, or by the carrier. That's the difference between the two. Either way the bootloader is still locked, only difference is who called for the locking.
For example, note 4 on tmobile does not have a locked bootloader, however, note 4 on at&t does. That decision was made by at&t, not Samsung. As far as I know, the at&t variant does not have a method for unlocking the bootloader yet so there's not much development for the device.
Compare to nexus devices, where Google automatically has the manufacturer lock the bootloader, but it being a development device, it's the easiest bootloader to unlock. It's literally a one line command in adb. HTC devices are locked but you can get an HTC dev code to unlock it from HTC.
I hope that makes sense. The best way to determine if your device has a locked bootloader is to visit the development forum or the general/Q&A forums for your device. If you have a locked bootloader and there is an unlock method, you only have to do it once (until you update or relock your bootloader). Some locked devices never get an unlock method. It designed to maintain the security and integrity of the device, but it also prevents user tampering.

Thank you for your thorough reply absinthesummer, very helpful.
However I'm still a little confused. My reading suggests to me that T-Mobile (910T) is *rootable* and the AT&T version (910S?) is not *rootable* but I'm in the UK and don't use these providers I use EE. And so I have the international variant of the Note 4 which is the 910F. I don't see a subforum or help for the UK EE version of the note 4 but as it's the 910F I assume that's the one I need to search for and not worry that EE will have put their own lock onto the 910F??
Now, because this happens to coincide with what you are saying has a locked bootloader or not, am I to assume that whether or not something is rootable is the same as whether or not it has an unlockable bootloader? i.e. is something only rootable or not because its bootloader is unlockable or not? If so therefore am I correct to assume that as the 910F which I have is rootable that it is also bootloadunlockable? And furthermore am I correct to assume that the very process of rooting itself unlocks the bootloader? Or perhaps in the case of the 910F it doesn't need to be so is even easier than Nexus devices? i.e. I just simply root and that in itself mean bootloader is already unlocked (and I am assuming that oem unlock is the same thing?)
I'm getting myself in a muddle I think!

Hehe it's totally cool, and yes your carrier could put a lock on it but that's incredibly rare in Europe due to frequent traveling between countries and the need to change Sims and carriers often... or at least that's what I've been told. The US carriers who lock their bootloaders are typically GSM carriers who do not expect you to need to root/carrier unlock/whatever. It's a control thing imo.
Anyway, your note 4 does not have a locked bootloader. If you check the development forum for your device you will see plenty of roms and guides and directions for rooting. That's usually a good indication that a device is unlocked (and those anticipating the release of new devices tend to get lock information prior to release, so they know which device they intend to buy).
Anyway, since you don't have a locked bootloader I wouldn't worry about it... that reminds me of a device I had for about a week, the LG L9. It had an oem bootloader lock but the international variant did not. We could root it & use a specially designed recovery with the bootloader locked but we couldn't flash a custom kernel (with a custom rom). They figured out that we could flash the international firmware and unlock that way, but it would make our display backwards (mirrored) and while that could be fixed, we would never be able to revert the boot screen. Now that's way too much trouble to go through just to unlock a bootloader and I did end up returning it and getting an s3 instead.
Bootloader locks are no fun, but they are not often placed on international devices for various reasons, so really I wouldn't worry about it too much.
If you get a device like a Google nexus, or an HTC that has a known locked bootloader, the bootloader and unlock method will be specifically mentioned in the routing guide. I hope that helps.
One more thing: rootability and locked bootloaders are not mutually exclusive, sometimes you can root devices with locked bootloaders and sometimes people will come up with ways around them (ie note 3 has safe strap recovery that runs parallel to stock recovery) to be able to use custom roms. However, if no exploit is found and there is no workaround, development will stall until one or both of those things is found. You may be able to root a device with a locked BL, but you may not be able to flash custom roms/kernels without a workaround. What I meant though is if you see a popular device with very little development, that's probably due to a locked bootloader and not having found a way around it yet. Most guides will explicitly mention the BL though if it's something you need to do

Yet another thoroughly helpful and detailed reply. Thank you very much indeed. You're a star!

How to unlock bootloader?

I don't have a Developer Edition yet I would like to unlock the bootloader. I want to root this thing but I don't know how to unlock the bootloader. Any help?
If you haven't noticed already, I have a Droid Maxx 2.

Also if possible I would like to keep my Verizon service please. The unlock code will not work because Verizon apparently won't allow it, so is there a way to unlock the bootloader?

I will get together with some of my friends from work and well take a look at this Devices security. Usually these new droids are TZ protected and I have the droid Maxx but I just purchased this device. I'm sure it won't be as tough as the Droid Maxx to Root or find a vulnerability in the security to unlock its bootloader. Do you know if it has trust zone security?

Motorola website says "your device does not qualify for bootloader unlocking." I assume Verizon, right?

Us t-mobile giveway to developer

I am giving away a new S7edge to a developer of my choice to work on and create root/unlock for the snapdragon version.
If you feel you are competent enough to provide root for this device then send me a PM.
If you feel you know a dev that can do it if they had the device in hand then post their name here in this thread or send me a PM. In the end I choose who gets it based on their background. I will pay for shipping, etc for the developer of choice. All I ask is for you to work diligently on this device.
This device is the future of locked, unrootable devices. The sooner we get through this barrier the better for the sake of all future devices. This isn't the end, only the beginning.
There will be no developer bashing in this thread and will have this thread closed immediately if it happens.

Good offer! This giveaway plus the bounty would hopefully entice someone. It's a good chunk of $$$!! I really hope someone with enough time and smarts would find root. I can live with TW as long as it is rooted (I'm a rooted 930F user). See T-Mobile Galaxy S7 Edge and AT&T forums for the bounty threads. I think there is another thread on the Sprint S7 forum as well.
OP's giveaway is for an SM-G935T, Qualcomm SnapDragon SD 820 Galaxy S7 Edge. All US variants are the same (SM-G935T/A/P/V) . A root for SM-G935T should work on the regular US S7 as well (SM-G930T/A/P/V). It is bootloader-locked and it will remain so unless Samsung releases an unlock, but due to the way the BL was locked, it would be near impossible anyway. So, no custom ROM.
It may be rootable if a stable exploit can be found. Folks have been comparing the US SnapDragon to Chinese SnapDragon S7, but it is not comparable. Here is a good summary regarding the bootloader situation:
mathieulh said:
The CROM lock does not exist on non-Chinese bootloaders
Samsung's Chinese handsets bootloaders have in 3 types of bootloader locks, the carrier lock, the CROM lock (which is enabled if the Chinese bootloader does not find the "KIWIBIRD" string written in the STEADY partition), and the reactivation lock, they are not carrier locked.
U.S. variants only have the Carrier and reactivation locks, there is no CROM lock to unlock on these devices (or any international variants either), U.S. variants are however carrier locked, the lock is hardcoded in the bootloader code (there is just no execution path to load an unsigned kernel on the consumer carrier locked variant bootloaders, there is no "lock" Qfuse anymore, the bootloader itself just has no carrier unlocking/locking support, it is always locked by design) and the bootloader is tied to the device ID, for example SM-G935F (which is One Time Programmable) and will refuse to run on anything but the device id that is hardcoded within it, obviously the bootloader is signed so you can't modify it, there is also a revocation mechanism involving Qfuses to make sure you can't downgrade to a vulnerable version (should one exist).
There are presumably Engineering versions of the bootloader that allow running unsigned kernels but those have not been leaked and they probably won't run on devices for which the production mode Qfuse has been blown (the device is in Engineering mode when that Qfuse is not set).
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Thread closed
There is already a thread on it here
http://forum.xda-developers.com/tmobile-s7-edge/how-to/t-mobile-s7edge-to-developer-t3383568

Can we expect to unlock the bootloader?

What are the chances of this device getting official bootloader unlock method?

ASUS phones do not have such a tightly locked boot Loader....unless Oreo security concerns have forced Asus to lock the BL on this phone, an unlock will be found. Soon.....

As soon as the device comes in market, I think Yes ASUS will allow the Bootloader to be unlocked.

Going by the way Asus is targeting its phone and the audience appeal. Definitely it will be developer friendly. With the recent drift by the Asian OEM's moving closer to "Openess" i believe they will allow BL unlock and release the kernel sources as well. (Example, Xiaomi's approach have change towards kernel sources. And now you can buy Redmi 5, minus wait time and flash sales). All the best to Asus for bringing in this device, looking forwards for Developer community to accept it and bring in some action.

Judging based on similarly priced phones in the market and from ASUS' track record. The bootloader will be unlockable and I am almosrlt certain that the developer community for this phone will grow very rapidly.

Tbh,I will buy the device only if bootloader is unlockable.Lets see.

I think it will have support for unlock bootloader. And with treble support it will definitely have lots of custom roms

Lots of Custom is lots of Sweetness.

I can't wait for the next sale.I'll definitely buy this device when Asus releases the kernel sources.All hail Asus! \m/

Any news on the bootloader unlock? I can't find any information online about it.

Thread created if anyone got the device can test it
https://forum.xda-developers.com/as...ow-to/guide-unlock-relock-bootloader-t3785710

Daruwalla said:
Any news on the bootloader unlock? I can't find any information online about it.
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Official Bootloader Unlock Tool & Kernal Sources are now available.

Here Unlike ,Xiaomi,Warranty is gone with the unlocking!!!