Hi,
I recently got a brand new s6 G920A AT&T version from an authorized reseller. To my surprise the firmware on it is very old - 5.0.2 with sw version G920AUCU1AOCE
I have heard that this firmware was a pre-release/developer/engineering version of s6 and has unlocked bootloader. Is that true?
How do I find if the bootloader is locked or unlocked in my samsung s6 or for that matter in *any Samsung* phone? Is it possible to check using Odin or some other tool on whether the bootloader is unlocked?
Please let me know your thoughts or ideas! If the above is true, I could perhaps extract the unlocked bootloader and share it with everybody else!!
Thanks!
Alright Interesting...
Use ADB:
=========================================
1. Make to go to about device and tap build number 7 times.
2. Go to developer options (Above About Device)
3. Check usb debugging and oem (Just in case)
4. Connect your phone to your computer via usb cable (Of Course)
5. Download ADB Fastboot if you haven't already =====> https://forum.xda-developers.com/showthread.php?t=2317790
6. Install it and after that it should be set-up
6. Type the command fastboot devices
7. Then type fastboot oem device-info (BTW I am sorry for letting you know now but i think you might need to be in downloading mode or something to use the commands)
8. It should tell you if it is unlocked or not
==============================================
Method 2:
1. Boot up the phone normally then open the phone application and go to the dialer
2. *#*#7378423#*#*
3. Then service info --> configuration
4. Then it should say one of the following:
---------------------------------------------------------------------------------------------------------------------------------
1. Bootloader unlock allowed --Yes >> This means that your Bootloader is Locked
2. Bootloader Unlocked - Yes >> This means that your Bootloader is unlocked
I hope i was helpful to you, if not then i'm sorry to have wasted your time.
Thanks @ROOT67! Let me try both options out and get back on this thread.
ROOT67 said:
Use ADB:
=========================================
1. Make to go to about device and tap build number 7 times.
2. Go to developer options (Above About Device)
3. Check usb debugging and oem (Just in case)
4. Connect your phone to your computer via usb cable (Of Course)
5. Download ADB Fastboot if you haven't already =====> https://forum.xda-developers.com/showthread.php?t=2317790
6. Install it and after that it should be set-up
6. Type the command fastboot devices
7. Then type fastboot oem device-info (BTW I am sorry for letting you know now but i think you might need to be in downloading mode or something to use the commands)
8. It should tell you if it is unlocked or not
==============================================
Method 2:
1. Boot up the phone normally then open the phone application and go to the dialer
2. *#*#7378423#*#*
3. Then service info --> configuration
4. Then it should say one of the following:
---------------------------------------------------------------------------------------------------------------------------------
1. Bootloader unlock allowed --Yes >> This means that your Bootloader is Locked
2. Bootloader Unlocked - Yes >> This means that your Bootloader is unlocked
I hope i was helpful to you, if not then i'm sorry to have wasted your time.
Click to expand...
Click to collapse
Both the methods did not work! Please see for details below.
ROOT67 said:
Use ADB:
=========================================
1. Make to go to about device and tap build number 7 times.
2. Go to developer options (Above About Device)
3. Check usb debugging and oem (Just in case)
4. Connect your phone to your computer via usb cable (Of Course)
5. Download ADB Fastboot if you haven't already =====> https://forum.xda-developers.com/showthread.php?t=2317790
6. Install it and after that it should be set-up
6. Type the command fastboot devices
7. Then type fastboot oem device-info (BTW I am sorry for letting you know now but i think you might need to be in downloading mode or something to use the commands)
8. It should tell you if it is unlocked or not
==============================================
Click to expand...
Click to collapse
I could not put it in fastboot mode. Do we know if the Samsung s6 supports fastboot mode? If so, how to put it in fastboot mode?
Also as a side note, in developer mode under settings, I could find check box for USB debugging but not for OEM. There was another post which said that OEM checkbox was added under developer options only after bootloader lock was introduced in 5.1.1 firmware. Not sure if this is true.
Method 2:
1. Boot up the phone normally then open the phone application and go to the dialer
2. *#*#7378423#*#*
3. Then service info --> configuration
4. Then it should say one of the following:
---------------------------------------------------------------------------------------------------------------------------------
1. Bootloader unlock allowed --Yes >> This means that your Bootloader is Locked
2. Bootloader Unlocked - Yes >> This means that your Bootloader is unlocked
Click to expand...
Click to collapse
When I dial this number, nothing happened. Is there a different number for Samsung s6?
It's not a pre-release/developer/engineering firmware. It's just a really old firmware which released for public officially.
jilebi said:
Both the methods did not work! Please see for details below.
I could not put it in fastboot mode. Do we know if the Samsung s6 supports fastboot mode? If so, how to put it in fastboot mode?
Also as a side note, in developer mode under settings, I could find check box for USB debugging but not for OEM. There was another post which said that OEM checkbox was added under developer options only after bootloader lock was introduced in 5.1.1 firmware. Not sure if this is true.
When I dial this number, nothing happened. Is there a different number for Samsung s6?
Click to expand...
Click to collapse
No other number is available that i know of, like the person above stated it is a old firmware version and with that said i would highly try to prevent any updates from installing. I would love to help you out, but since i have no idea as to what would be needed to tell if the bootloader is unlocked, but i do know since Samsung is against us rooting and using our devices the way we want, it is safe to assume the bootloader is locked and because you have at&t variant. Your best bet to get your device bootloader information is to look around on the XDA forums.
Do you have any details on whether the bootloader was locked or unlocked for this old version? How can one test or check if bootloader is locked?
forumber2 said:
It's not a pre-release/developer/engineering firmware. It's just a really old firmware which released for public officially.
Click to expand...
Click to collapse
jilebi said:
Do you have any details on whether the bootloader was locked or unlocked for this old version? How can one test or check if bootloader is locked?
Click to expand...
Click to collapse
All AT&T branded nearly-new (including S6) Samsung devices has a non-unlockable locked bootloader.
There's no way to test that.
here are a couple of test scenario that i can think of. let me know your thoughts on them
- if the device is rooted, load a custom recovery like TWRP. next, try to boot into custom recovery. if it boots into custom recovery, bootloader is unlocked. if not, try to restore factory recovery using odin.
- if the device is rooted, load a custom ROM. next, try to boot into custom ROM. if it boots into custom ROM, bootloader is unlocked. if not, try to restore factory ROM using odin.
Will these test scenarios work? If not, what are the potential issues you see?
forumber2 said:
All AT&T branded nearly-new (including S6) Samsung devices has a non-unlockable locked bootloader.
There's no way to test that.
Click to expand...
Click to collapse
jilebi said:
here are a couple of test scenario that i can think of. let me know your thoughts on them
- if the device is rooted, load a custom recovery like TWRP. next, try to boot into custom recovery. if it boots into custom recovery, bootloader is unlocked. if not, try to restore factory recovery using odin.
- if the device is rooted, load a custom ROM. next, try to boot into custom ROM. if it boots into custom ROM, bootloader is unlocked. if not, try to restore factory ROM using odin.
Will these test scenarios work? If not, what are the potential issues you see?
Click to expand...
Click to collapse
- There's no custom recovery or custom kernel for SM-G920A, because of the reason I've wrote above.
- Installing a custom ROM doesn't require an unlocked bootloader unless the ROM doesn't require custom kernel. (Custom ROMs for SM-G920A don't require custom kernel (except leaked engineering/debugging kernel from Samsung for disabling dm-verity))
forumber2 said:
- There's no custom recovery or custom kernel for SM-G920A, because of the reason I've wrote above.
- Installing a custom ROM doesn't require an unlocked bootloader unless the ROM doesn't require custom kernel. (Custom ROMs for SM-G920A don't require custom kernel (except leaked engineering/debugging kernel from Samsung for disabling dm-verity))
Click to expand...
Click to collapse
Got it. Thanks. That makes sense.
Here is another option. For making custom recovery, my understanding is that partition info is needed. If the device is rooted e.g. using Pingpong (which works for this Android version), then one can get a partition info and compile TWRP for G920A. If so, can one try to install custom recovery like TWRP and verify if bootloader is locked? It feels to me that this may work. Do you see any flaws?
One possible flaw is that if bootloader is locked, it will prevent recovery from loading. So the phone will be without a working recovery. In that case, can factory recovery be re-installed using Odin?
Also, will any of the above steps trigger the KNOX flag?
jilebi said:
Got it. Thanks. That makes sense.
Here is another option. For making custom recovery, my understanding is that partition info is needed. If the device is rooted e.g. using Pingpong (which works for this Android version), then one can get a partition info and compile TWRP for G920A. If so, can one try to install custom recovery like TWRP and verify if bootloader is locked? It feels to me that this may work. Do you see any flaws?
One possible flaw is that if bootloader is locked, it will prevent recovery from loading. So the phone will be without a working recovery. In that case, can factory recovery be re-installed using Odin?
Also, will any of the above steps trigger the KNOX flag?
Click to expand...
Click to collapse
You don't have to get partition info, and compile TWRP. All S6 variants are using same partition name scheme and there are no difference on TWRP builds between S6 variants (except kernel and DTB).
The bootloader won't allow you to flash any custom recovery image (via Odin or in Android OS). If you could flash it, It won't boot it up anyway.
I don't have any idea about the KNOX trigger on AT&T variant devices, but I think it won't increase anyway.
forumber2 said:
You don't have to get partition info, and compile TWRP. All S6 variants are using same partition name scheme and there are no difference on TWRP builds between S6 variants (except kernel and DTB).
The bootloader won't allow you to flash any custom recovery image (via Odin or in Android OS). If you could flash it, It won't boot it up anyway.
I don't have any idea about the KNOX trigger on AT&T variant devices, but I think it won't increase anyway.
Click to expand...
Click to collapse
Sorry, I perhaps misunderstood from your last post that since custom recovery is not available for G920A it implied its partition info was different from other variants. If it is the same partition structure for all variants, then I guess we can use the TWRP for the G920F international version for which bootloader is unlocked.
Now that we agree that TWRP is available for use on G920A, the next question is how to load it. My thought is that if the device is rooted that means one can use dd at root shell prompt to write TWRP to the recovery partition, without using Odin or the current bootloader. Do you agree?
Not sure I understand why you say that if one could flash TWRP it would not boot anyways. If bootloader is unlocked (which is what we are testing here), then it should boot, right?
jilebi said:
Sorry, I perhaps misunderstood from your last post that since custom recovery is not available for G920A it implied its partition info was different from other variants. If it is the same partition structure for all variants, then I guess we can use the TWRP for the G920F international version for which bootloader is unlocked.
Now that we agree that TWRP is available for use on G920A, the next question is how to load it. My thought is that if the device is rooted that means one can use dd at root shell prompt to write TWRP to the recovery partition, without using Odin or the current bootloader. Do you agree?
Not sure I understand why you say that if one could flash TWRP it would not boot anyways. If bootloader is unlocked (which is what we are testing here), then it should boot, right?
Click to expand...
Click to collapse
A custom recovery is not available for G920A, because no one could try any custom recovery on G920A due to locked bootloader.
Yes you can write the recovery image via dd at root shell prompt.
And yes, If bootloader is unlocked, it will boot it up.
Sorry to ressurect this old thread, but can you (or anybody else who is knowledgeable) answer the following?
1. Since custom recovery is not available for G920A, which of the Tmobile/Sprint/International versions of TWRP custom recovery would you recommend to use for testing if bootloader is unlocked, using either ODIN or dd method?
2. If bootloader is unlocked, you are suggesting below that it should boot up. However, if it is locked, then will the phone still boot up? i.e. if one does not go into recovery mode, will it still boot up or does the bootloader check if both recovery and kernel are signed and if it finds that the recovery is unsigned, will it also prevent the signed kernel from booting up?
Thanks!
forumber2 said:
A custom recovery is not available for G920A, because no one could try any custom recovery on G920A due to locked bootloader.
Yes you can write the recovery image via dd at root shell prompt.
And yes, If bootloader is unlocked, it will boot it up.
Click to expand...
Click to collapse
I rooted my s7, latest version of 8.0 United Kingdom (g930fxxu4esae build r16nw.g930fxxs5esf6). I used TWRP and magisk.
All was well until I rebooted, then got the dreaded "custom binary blocked by frp lock". I was able to take the stock rom and install the AP file, and now it's working again except that of course root is gone. I suspect that if I attempt to root again, I will run into the same error on a reboot.
I've done some googling but haven't found anything really reliable sounding about getting around this problem.
EDIT: UPDATE: I've flashed the latest version of BTU on phones 1 and 2. I've successfully rooted phone 1 and it seems to be sticking. Phone 2 I'm still working on, it doesn't have to be rooted though as it's more of a backup for gaming. Thanks again to everyone in this thread for all the good advice and info.
You are going to have to re flash you current firmware unrooted and before you root, enable OEM unlocking in developer options AFTER setting up your google account(you have to use the same google account as you did before), unfortunately there is no way of force enabling OEM unlock with a flashable zip on the s7, well least to my knowledge. FRP lock is googles factory reset protection, which stops people from factory resetting a phone and then just use their google account instead of the one they don't know the password too, and it stops custom binaries like trwp from booting and even a stock binary that has been rooted from booting because it thinks you could be trying to bypass FRP.
Enabling OEM unlocking with disable FRP lock on the device, allowing you to use custom binary and boot normally without the checks.
Viper4060 said:
You are going to have to re flash you current firmware unrooted and before you root, enable OEM unlocking in developer options AFTER setting up your google account(you have to use the same google account as you did before), unfortunately there is no way of force enabling OEM unlock with a flashable zip on the s7, well least to my knowledge. FRP lock is googles factory reset protection, which stops people from factory resetting a phone and then just use their google account instead of the one they don't know the password too, and it stops custom binaries like trwp from booting and even a stock binary that has been rooted from booting because it thinks you could be trying to bypass FRP.
Enabling OEM unlocking with disable FRP lock on the device, allowing you to use custom binary and boot normally without the checks.
Click to expand...
Click to collapse
Correct basically turn FRP lock off it's a pain in the ass.
Also @kettir this is the final release of BTU not the one you have in your post 》》https://www.sammobile.com/samsung/galaxy-s7/firmware/SM-G930F/BTU/download/G930FXXU5ESD2/270504
cooltt said:
Correct basically turn FRP lock off it's a pain in the ass.
Also @kettir this is the final release of BTU not the one you have in your post 》》https://www.sammobile.com/samsung/galaxy-s7/firmware/SM-G930F/BTU/download/G930FXXU5ESD2/270504
Click to expand...
Click to collapse
Thanks for more great advice and info. It appears that now the requirements are:
Download the latest BTU as per your note because I like it better
Flash it to attain a "stock" system.
Go through the minimum setup after reboot and get developer options.
Set up google account
Enable OEM unlocking (and USB debugging of course)
flash TWRP
go into recovery immediately
Use TWRP to flash magisk
go back into download mode immediately
flash only the AP from the stock firmware
And this might, possibly, achieve root with magisk, while keeping the stock bootloader. That is, if I understand what TWRP and magisk are actually doing to the system. I.e., TWRP replaces the system part that handles recovery, while magisk roots the phone without changing the system, so that TWRP is the problem for FRP.
I'm Trying to Root my Galaxy A51 using magisk & this is first time i'm trying to root phone. i followed this guide https://forum.xda-developers.com/t/...flash-official-firmware-binary-3-may.4053065/
when i tried to flash AP file of magisk, i'm getting error "Only Official release binaries are allowed to be flashed (VBMETA)"
i tried to flash stock VBMETA but it doesn't Root the Phone.
i tried to flash twrp recovery but still getting same error message "Only Official release binaries are allowed to be flashed".
is there any way to solve this problem & root my phone ??
Did you read this thread?
[SOLVED]Stuck on Only official released binaries are allowed to be flashed(vbmeta)
Hi! I was following the root guide [RECOVERY][UNOFFICIAL][ROOT] TWRP for Galaxy A70 and it seems that I forgot to check that the OEM unlock was still enabled after flashing vbmeta.tar and flashing TWRP v3.3.1-5, now my phone is stuck in a screen...
forum.xda-developers.com
ze7zez said:
Did you read this thread?
[SOLVED]Stuck on Only official released binaries are allowed to be flashed(vbmeta)
Hi! I was following the root guide [RECOVERY][UNOFFICIAL][ROOT] TWRP for Galaxy A70 and it seems that I forgot to check that the OEM unlock was still enabled after flashing vbmeta.tar and flashing TWRP v3.3.1-5, now my phone is stuck in a screen...
forum.xda-developers.com
Click to expand...
Click to collapse
yes, i tried & didn't work.
i doubt that the recent Samsung update has something to do with it. maybe Samsung has forcefully locked bootloader so that no one else can flash custom os.
I Found the solution. KG STATE was Prenormal in bootloader.
Solution is simple,
- turn on wifi/internet
- enable developer option
- open developer option Settings>Developer Options
- check if "OEM Unlocking" is disabled or not. if disabled then it's OK & ready to flash