New video guide below
VIDEO GUIDE
1. *VERY IMPORTANT* We need to back up your broken persist.img and store it in a safe place. PC preferred. We will need this later. Do not leave the backup on the device as the next step will wipe the device.
*IF YOU LOOSE THIS PERSIST.IMG BEFORE WE MODIFY IT WITH A CALIBRATION, YOU LOOSE ALL CHANCE OF FIXING THIS YOURSELF*
*IT HOLDS IMPORTANT FP CALIBRATION DATA THAT WE WILL BE OVERWRIGHTING IN THE NEXT FEW STEPS*
Note: This requires root
Type this into terminal or ADB shell with root privileges.
Code:
dd if=/dev/block/bootdevice/by-name/persist of=/sdcard/persist.img
Backup the partition to another device. Preferably a PC as you may need one in the later steps.
2. Next we have to restore our OS to an earlier OOS. (10.5.4 is what I used and recomended)
Use the MSMTool to restore your device to 10.5.4.Note: You will loose your unlocked bootloader and will be required to unlock your bootloader once more.
Guide and Source for MSMTool
MSMTool 10.5.4 Download
3. Next step is to unlock the built in 'Factory Mode' I have a guide on how to do this below.
[GUIDE] Unlock Factory Mode *root*
4. Now we need to perform a FP calibration. We want to fail.
Enter Factory Mode as shown in the previous guide. (*#801# in the stock dialer)
Swipe over to "Device Debugging"
Select "Finger print test"
Select "Finger print calibration test(Pure White - 90% Blue)
Select "Start Test"
Keep on going through the tests (You must hold an object or your finger over sensor on all BUT THE BLACK RUBBER TEST of these test for it to work!)
The test will fail and this is what we want. There should be a lot of red lines, if you only have one or two try again.
5. We need to extract the the old broken persist.img
NOTE: It is important that we extract the backed up persist.img as it has been unmodified by our recent calibration. This persist.img although broken still has all our working calibrations on it including Finger Print calibrations.
The way I did this is by opening it extracting it via 7-ZIP on my PC
Once extracted move the 'DATA' folder and the 'ENGINEERMODE' folder to the root of your sdcard.
6. Download a root explorer. I highly recommend 'Solid Explorer' from the Play Store.
Open 'DATA' folder and delete 'gf_persist.so'
Select the 'DATA' and 'ENGINEERMODE' folders you just put on the device and place them at /mnt/vendor/persist/
It should ask you if you want to keep the old or new files. Select to keep the new.
Reboot.
7. If you followed all my steps correctly this you should be able to go into settings and add your fingerprints.
Why does this work?
Good question... I think what is happening is something in the persist partition breaks which causes the device to think that the sensor is not calibrated when in fact it still is.
When we start and fail a new calibration this fixes whatever was broken in our partition. But now we have a failed calibration.
So what we do is take the files from our backed up persist partition and move over all the necessary files that have our original calibration. But now our partition has the part of it that wasn't working fixed.
I spent a good many days working on this fix (1-2 hundred hours or so). I hope you can be respectful if you have issues. Please kindly ask below and I'll do my best to help.
Thanks worked on.my TMobile OnePlus.
I can confirm working on OOS 1.5.6 too. I downgraded from 10.5.9 with downgrade rom, which restores OOS to 10.5.6, and followed your guide and it worked as a charm. The only problem is that i cannot lock back the bootloader, cause it breaks FP again. Did you maybe try to lock it to try? Nice work man.
T-Mobile OnePlus 8 here. Stock firmware, orginally had my bootloader unlocked, rooted with TWRP and Magisk, backed up modem, converted to international firmware (10.5.7), lost signal, had to restore modem, ota'd to 10.5.9, unlocked bootloader again, rooted, etc. All while having a working FP the whole time. Ended up flashing EdXposed via Magisk, broke SafetyNet, etc, did a factory reset on TWRP (3.4.0-1 test), wiped data, rebooted recovery, rebooted system, booted back to TWRP. Installed Magisk to see if it'll boot with root, same thing. MSM'd back to T-Mobile firmware, then converted to international again. After the conversion was done and I unlocked bootloader and rebooted to system, my FP was broken. Ended up MSM'ing back to T-Mobile stock to see if it would work again, nothing.
TL;DR does this method only work if I had a working FP to begin with like it did stock out of the box?
TheKnux said:
T-Mobile OnePlus 8 here. Stock firmware, orginally had my bootloader unlocked, rooted with TWRP and Magisk, backed up modem, converted to international firmware (10.5.7), lost signal, had to restore modem, ota'd to 10.5.9, unlocked bootloader again, rooted, etc. All while having a working FP the whole time. Ended up flashing EdXposed via Magisk, broke SafetyNet, etc, did a factory reset on TWRP (3.4.0-1 test), wiped data, rebooted recovery, rebooted system, booted back to TWRP. Installed Magisk to see if it'll boot with root, same thing. MSM'd back to T-Mobile firmware, then converted to international again. After the conversion was done and I unlocked bootloader and rebooted to system, my FP was broken. Ended up MSM'ing back to T-Mobile stock to see if it would work again, nothing.
TL;DR does this method only work if I had a working FP to begin with like it did stock out of the box?
Click to expand...
Click to collapse
Just follow the guide, you'll have it working. You just have to backup your current persist
dzontra83 said:
Just follow the guide, you'll have it working. You just have to backup your current persist
Click to expand...
Click to collapse
So back it up even though it's broken? I'm on T-Mobile stock again, locked BL. Should I unlock, root, then pull persist and back it up?
TheKnux said:
So back it up even though it's broken? I'm on T-Mobile stock again, locked BL. Should I unlock, root, then pull persist and back it up?
Click to expand...
Click to collapse
Exactly, a T-Mobile user confirmed guide to work, check 2nd post
While on 10.5.7, unlocked bootloader, I flash TWRP, then reboot, and it boots back to TWRP. When I flash Magisk 20.4 zip in TWRP, it goes to boot, then enters CrashDump Mode. When I try and use the flash-all to downgrade to 10.5.4, I get a bunch of fastboot "cannot flash critical partitions" errors, it fails, and goes back to CrashDump Mode. What am I doing wrong? Also, is it really necessary to downgrade to an earlier version of OOS to use Engineering Mode or can I use 10.5.7?
TheKnux said:
While on 10.5.7, unlocked bootloader, I flash TWRP, then reboot, and it boots back to TWRP. When I flash Magisk 20.4 zip in TWRP, it goes to boot, then enters CrashDump Mode. When I try and use the flash-all to downgrade to 10.5.4, I get a bunch of fastboot "cannot flash critical partitions" errors, it fails, and goes back to CrashDump Mode. What am I doing wrong? Also, is it really necessary to downgrade to an earlier version of OOS to use Engineering Mode or can I use 10.5.7?
Click to expand...
Click to collapse
When you unlock bootloader, only boot into TWRP, then install magisk, i thin it Is still recommend to only boot into TWRP, not to flash it.
dzontra83 said:
When you unlock bootloader, only boot into TWRP, then install magisk, i thin it Is still recommend to only boot into TWRP, not to flash it.
Click to expand...
Click to collapse
Thank you so much, that worked! New problem, what do I do since I can't downgrade to an earlier OOS (10.5.4)?
Performing the test on T-Mobile 10.5.7, when performing the test, nothing is failing after pressing start test. Its all passing, what should I do?
When trying to downgrade using the 10.5.4 MSM Tool. it gives an error of "Unsupported Target TMO" and "param preload" and fails.
TheKnux said:
Thank you so much, that worked! New problem, what do I do since I can't downgrade to an earlier OOS (10.5.4)?
Performing the test on T-Mobile 10.5.7, when performing the test, nothing is failing after pressing start test. Its all passing, what should I do?
When trying to downgrade using the 10.5.4 MSM Tool. it gives an error of "Unsupported Target TMO" and "param preload" and fails.
Click to expand...
Click to collapse
Did you follow the instructions in test exactly? In second test you must't press the sensor.
Can help you with TMobile model, I have international one.
I figured it out. I was just being a dumbass I guess. Has anyone noticed the fingerprint sensor not being able to read that well compared to before it was broken? It seems like it fails a lot more before it succeeds. Unless now that it's working, we can perform the calibration again and it'll work better?
TheKnux said:
I figured it out. I was just being a dumbass I guess. Has anyone noticed the fingerprint sensor not being able to read that well compared to before it was broken? It seems like it fails a lot more before it succeeds. Unless now that it's working, we can perform the calibration again and it'll work better?
Click to expand...
Click to collapse
Don't know about that, mine works just fine
So I think I messed up, I ended up performing the calibration again, while it was already working, and now it says "fingerprint hardware not present" any suggestions on how to fix? I performed the instructions in the guide (again) and nothing worked. When the error pops up, if I press back, the error message goes away and the FP icon is there. When I tap on it, it lights up white but doesn't vibrate or register anything. I already used the MSM tool to go back to Tmobile stock, then used the fastboot ROM to go to Global 10.5.7, followed the guide again, still nothing.
TheKnux said:
So I think I messed up, I ended up performing the calibration again, while it was already working, and now it says "fingerprint hardware not present" any suggestions on how to fix? I performed the instructions in the guide (again) and nothing worked. When the error pops up, if I press back, the error message goes away and the FP icon is there. When I tap on it, it lights up white but doesn't vibrate or register anything. I already used the MSM tool to go back to Tmobile stock, then used the fastboot ROM to go to Global 10.5.7, followed the guide again, still nothing.
Click to expand...
Click to collapse
The initial backup of the persist.img should do the trick, if you repeat the process once again, it should work
dzontra83 said:
The initial backup of the persist.img should do the trick, if you repeat the process once again, it should work
Click to expand...
Click to collapse
I tried that, multiple times. Still not working. Is it possible for someone to upload their persist.img so I can try it or is it device specific? Granted, I pulled my initial persist.img from stock rooted Tmobile ROM AFTER I broke it even though it worked before (long story). I wasn't able to downgrade to 10.5.4 because when I tried using the MSM tool, it gave me a TMO device error and I couldn't use a fastboot ROM to go to 10.5.4 cause it kept entering CrashDump mode every time it tried rebooting to fastboot to finish the flash process .
TheKnux said:
I tried that, multiple times. Still not working. Is it possible for someone to upload their persist.img so I can try it or is it device specific? Granted, I pulled my initial persist.img from stock rooted Tmobile ROM AFTER I broke it even though it worked before (long story). I wasn't able to downgrade to 10.5.4 because when I tried using the MSM tool, it gave me a TMO device error and I couldn't use a fastboot ROM to go to 10.5.4 cause it kept entering CrashDump mode every time it tried rebooting to fastboot to finish the flash process .
Click to expand...
Click to collapse
Your cannot use someone else's persist, you must't use yours.
dzontra83 said:
Your cannot use someone else's persist, you must't use yours.
Click to expand...
Click to collapse
What about someone else's DATA and ENGINEERINGMODE folders? I've tried everything. Even recalibrating multiple times. It's not giving me a bunch of errors like it did before, just one error. The last error is FAIL! OPERATION_STEP_GET_KB_CALIBRATION TEST FAIL:GF_ERROR_GENERIC
Just wondering, what is the point of downgrading to an earlier OOS? If I was able to do it on the Tmobile firmware with success, is there an importance in downgrading?
Thank you so very very much!!! I have a T-Mobile 7T Pro 5G McLaren which hasn't had a working fp in almost 2 months. I hadn't made a backup of persist before the fp broke, so I thought I was completely screwed. Luckily, I did make a backup of persist before trying to use the fp calibration tool myself without any luck shortly after it broke (basically just clicking stuff and guessing lol). Found this thread and I had my FP scanner working again perfectly in less than 15 minutes!!!! Thank you soooo much for all the hours and effort you put into figuring this out!!!!!!!
Didn't have to run the msm tool to revert to older version of OOS and lose all my data either!!
Just one question and it's just for my curiosity. Why do we delete "gf_persist.so" from our original persist.img before copying/pasting into /persist partition after "calibration"? Is gf_persist.so not a file containing part of the original calibration? Is that the file which is being fixed by running the hidden calibration commands?
If anyone can help me, it would be much appreciated. https://forum.xda-developers.com/oneplus-8/help/broken-persist-img-problems-t4129587
This is an extremely urgent request! I AM WILLING TO PAY $100 cash to anyone who can help me fix this ASAP.
Latest oxygen OS update downloaded today and now I'm on a constant bootloop and can't get back into my phone. It keeps saying "Turn Off" and then back to the restart oneplus logo and keeps loading from there. I can manage to get into Fastboot mode, and recovery mode, but the stock recovery is basically useless. It only presents me with 4 options:
FORMAT DATA (unacceptable for me)
RESTART
POWER OFF
ADVANCED OPTIONS (reboot into fastboot, reboot into recovery)
The recovery menu has no option to wipe cache/data at all!
My Oneplus 8 Pro phone model is the IN2025 (IN11AA)
I have crucial data on here that I havent backed up yet, i really can't afford to lose the data! I have seen the MSM unbrick tool method and it apparently will factory wipe my phone which is not an option.
Not sure if this is related to magisk or not, but i had magisk installed and each time i do an OTA update, i restore magisk to stock image by following this guide and there have been no issues until now.
I am in exactly the same boat. Same thing is happening to me.
Extracting a boot.img from the 2 new updates doesn't work (both are 0kb boot.img files) and extracting a boot image from the IN2025_11_C_OTA_1100 OTA image doesn't boot via fastboot either
I've got some bad news for you, it seems that the A12 update recently pushed and magisk really hate each other and will brick the phone. I couldn't recover from it and had to blast the whole thing with MSM reload. https://forum.xda-developers.com/t/something-went-horribly-wrong.4431335/
omega552003 said:
I've got some bad news for you, it seems that the A12 update recently pushed and magisk really hate each other and will brick the phone. I couldn't recover from it and had to blast the whole thing with MSM reload. https://forum.xda-developers.com/t/something-went-horribly-wrong.4431335/
Click to expand...
Click to collapse
yeah i figured. i did the same and ****ing bit the bullet and MSM'd my ****. Another guy is recommending switching partitions and booting from the other one, on my reddit thread though, i wish he had messaged me before I blasted my **** with MSM.
https://www.reddit.com/r/AndroidQuestions/comments/udix5n