yashsingh1/xdaforums huggingface dataset:
[OnePlus 9RT] Gerzan148:
Hi bro

I tried and it worked. I managed to flash rom and get out of crashdump.

Thanks for reply and @Valdem Also thanks to you for replies
[OnePlus 9RT] ichirokazuki:
Hi sir. I have a problem on OOS now. My signal are missing.

I was try to downgrade and flash again using OOS C.05 fastboot rom but still same.

I saw on your AFH you was upload COS C.06 fastboot rom. But, i hear that COS rom will make fastboot gone.

Is your fastboot COS rom are safe and still have fastboot? I want to try. Thanks before.
[OnePlus 9RT] penguinus:
C.06 has unlocked fastboot.
[OnePlus 9RT] silent_eyes:
Can I use it to downgrade from cos 12.1?
[OnePlus 9RT] xtymmms1021:
hi i got the same problem when i tried to flash my 9rt to a11.

fastboot reboot fastboot

make my 9rt stuck at boot loop.

do you have any progress on this problem?
[OnePlus 9RT] penguinus:
Was it downgrade from Android 12 based ROM? Bootloop is possible in this case. If you can enter bootloader (hold Vol- on reboot), you may try to flash again. But probably you will need ROM that you had installed before A.11.
[OnePlus 9RT] Barabaz:
Edit:

any recommended custom kernels aside from the stock rom?
[OnePlus 9RT] Gerzan148:
Hi guya my 9rt I flashed Oxygen OS A.11 and locked bootloader not getting Android 12 oxygen os ota update .any ideas other than oxygen updater app i don't know and trust that app so bro
[OnePlus 9RT] xiaowang0131:
I hope the thread owner can sticky this message on thread:

FOR CHINA USERS

IF YOU UPGRADE TO COS12.1 WHICH IS BASED ON ANDRDOID 12 (ENDS WITH C.04), DO NOT UPGRADE DIRECTLY, BECAUSE COS12.1 OF THIS VERSION CAN NOT BOOT INTO FASTBOOTD, SO YOU WILL BRICK YOUR PHONE.

IF YOU GO TO THE REPAIR CENTER AND FLASH YOUR PHONE, BEAWARE BECAUSE THEY WILL PROBABLY FLASH COS A.02 FOR YOU, AND THAT VERSION CAN NOT ENTER BOOTLOADER. UPGRADE TO A.14 FIRST THROUGH SYSTEM UPGRADE CENTER, THEN YOU CAN PROBABLY START FLASHING YOUR PHONE..
[OnePlus 9RT] ethan_mars_93:
I was on c05 and i flashed android 11 cos , and i encountered bootloop and I couldn't revivey phone

What should i do
[OnePlus 9RT] penguinus:
See my comment above
[OnePlus 9RT] donvol:
I'm new to OnePlus phones after using Samsung for a while, I purchased a China version MT2110 and it came with oxygenos without my knowledge, is it possible to get back onto coloros?

I'm currently running Oxygenos 12.1 c.05.
[OnePlus 9RT] Valdem:
Yes it is possible. But I didn't see instructions and firmwares distributed in english speaking forums.

Ping @penguinus for details. He develop and maintain fastboot versions of firmware with ColorOS.
[OnePlus 9RT] donvol:
Thank you for the advice
[OnePlus 9RT] Burninjiyad:
Can anyone help?I unlocked my bootloader and installed adb nd from platform tools went into cmd then as per pixel experience rom's forum instruction,i directly gave command to flash rom then it got stuck to bootloop after a lot of failures in processes in cmd

So i tried to flash the above rom and after installing a bit when it tries to reboot into fastbootd,it says waiting for device and continues to loop in phone

Note:This is my first time trying to flash rom or anything
[OnePlus 9RT] OMGJL:
I've just worked around this issue. (I have upgraded to Color 12.1 from factory default Color OS 12, and now I want to use Oxygen OS)

Simply unzip the Fastboot ROM, and edit upgrade.bat, on line 11, change

fastboot --set-active=a

to

fastboot --set-active=b

and flash it with install.bat, it will success.

In case if you worry future issue would raise, you can flash it again after modifying the line back to original.

I've tested it successfully, no issue at all.
[OnePlus 9RT] xiaowang0131:
I am sure we are not talking about same case, 9RT colors roms are awful, as many version can not enter fastbootd at all. The slot is not the issue at all. And your current slot can be different it you skip some version in the past.
[OnePlus 9RT] OMGJL:
It is the same issue, I was on the latest stable Color OS, and I was NOT able to access fastbootd, it will keep rebooting and is going nowhere.

HOWEVER, I can access fastbootd after using slot b, and after flashing the fastboot ROM using slot b, I am able to access fastbootd using both slot a and b.
[OnePlus 9RT] ThommyJoe:
Hello!

First of all, Thanks for an awesome development thread for 9RT. ColorOS was driving crazy until I found this.

I successfully switched my OS from COS to OOS thanks to this, but then I accidentally OTA undated to OOS 12, which I'm not happy with.

If I just do the steps here over to my phone, would it be downgraded to OOS 11? My bootloader has not been relocked yet.

THank you !
[OnePlus 9RT] Valdem:
This firmwares should not be used for downgrade from Android 12. The high probability to get boot loop on flashing because of changes in the Android 12 bootloader.

I would recommend you to find downgrade firmware (it was released for downgrade from Android 12 beta) or ask @penguinus to assist you with the downgrade procedure (he maintain correct version of fastboot firmware for this).
[OnePlus 9RT] keckek:
I have exactly the same problem, trying to install OOS from latest COS Android 12 and even tried to change from Slot A to Slot B as @OMGJL suggested. Still boot looping now, can't enter fastbootd :( . Can @penguinus having any advises for me. I think something change with COS Android 12 Bootloader which need to be downgraded to COS Android 11 before flashing OOS A series
[OnePlus 9RT] OMGJL:
I actually didn't mention a step I did.

After I unlock the bootloader, run the flash bat (which cleaned all partition), I have had boot loop and unable to do anything.

I flashed the Pixel Experience ROM from this forum on slot B, (Slot A won't work at this moment)

then I flashed the latest Oxygen OS Fastboot ROM on slot B, (Slot A won't work before flashing)

After flashing the fastboot ROM, everything is all good, slot A/B both work as intended.
[OnePlus 9RT] penguinus:
I can confirm that if you try to downgrade from android 12 (C) based ROM to android 11 (A) based ROM it may cause bootloop. In order to downgrade using fastboot ROM package, you should use fastbootd mode instead of fastboot. Also you should manually edit upgrade.bat script to remove the line

fastboot reboot fastboot

Alternatively you may use updated ROM package with changed scripts. That scripts takes into account fastbootd mode automatically.

Steps to downgrade are as follows (using upgraded scripts):

1. Do all preparations on PC, i.e. install drivers, setup adb and fastboot to work correctly.

2. Connect the phone to PC.

3. Reboot to fastbootd mode from working ROM with.

adb reboot fastboot

3. Start install.bat

4. Script will ask if you want to install magisk. Answer Y/N

5. At the end script will ask to reboot the phone. Answer N.

6. Reboot the phone to bootloader (fastboot mode) with the command

fastboot reboot bootloader

7. Start upgrade1.bat. It will ask about magisk installation again. Answer Y/N

8. After script is finished, reboot the phone manually.

OOS A.11 with updated scripts

Steps to recover if you already got bootloop.

1. Download Android 12 (C) based ROM for fastboot. I recommend to use version that was installed before, but probably you may use other version too. I.e. OOS C.07

2. Enter fastboot/bootloader mode by pressing Power + Vol- button.

3. Start upgrade.bat

4. After it will finish, phone should be recovered and boot to the ROM. If you want to downgrade, you may use instruction above.

Alternatively, there is official downgrade ROM that may be used without fastboot and even with locked bootloader. It will downgrade to version A.07
[OnePlus 9RT] keckek:
I'll try as your suggestions. Thank you. My phone is MT2110 was running C.07 COS before. Seems I have to find COS C.07 to restore to previous stage. And I also can not boot to fastboot/bootloader via Power+ Vol-, it displays logo OnePlus Fastboot then immediately reboot :( may be my fastboot also be damaged already:(
[OnePlus 9RT] penguinus:
If fastboot is damaged, the only way to restore is MSM tool. It is not available in public. Two options are:

- official oneplus service

- third party paid service
[OnePlus 9RT] Dan_Jacques:
Hi! I bought a chinese OP9RT and it came with A05 OxygenOS. Stock OTA shows C05 version. Locked bootloader

How can I update to newest Oxygen 11 avoiding ColorOS?
[OnePlus 9RT] xiaowang0131:
I got why you are working.

You must be on slot a with latest color os which cannot enter fastbootd, while your solt b is a older version of color os which can enter fastbootd.

HOWEVER, in my case, both of my slot must be problematic. Your answer does help people in some cases, thanks for that, but a better solution is to make sure that you have a ROM which can enter fastbootd installed.
[OnePlus 9RT] OMGJL:
That might be the case.

This is the official tool to downgrade Color OS, https://www.oneplusbbs.com/thread-6387108-1.html

Though it's in Chinese and may not help non-Chinese people, this tool requires a bootable color os as you'll need to use Android debugging to start its process. (You can try use Google Translate phone app with the camera translate tool),

in case Chinese isn't displayed properly, you may need to go control panel - clock and region - region - administrative - Language for non-unicode program - Chinese Simplified, China - OK - Restart. This won't change your Windows display language to Chinese, but to display Chinese app properly.

The other way is to get chat support and make support team arrange a remote 9008 recovery, though it might only work with the Chinese support team I am not very sure about that..

As an owner of OnePlus 3, OnePlus 5T, and OnePlus 9RT. I still think OnePlus do still make good phones but seeing how they deliberately make flashing official ROM this hard, my next phone is very unlikely going to be OnePlus anymore.
[OnePlus 9RT] g96818:
C05 is not COS. it is OOS 12
[OnePlus 9RT] aileenqwinn:
hi, can anyone help:

last time I flash to op9rt-oos-A07 ok.

today I download Fastboot ROM OxygenOS A.11 zip and follow the instructions till

- instead of install.bat you need to run upgrade.bat in command line window

when process to 'Rebooting into fashboot', my phone keep looping restart............

I even cannot shutdown it :‘(

Is there any suggestion?
[OnePlus 9RT] itsawoozie:
Hi fellas

I think I did many things wrong

such as

I bought a oneplus 9RT from China Guangzhou

It had Color OS 13 and as you guess It is in orange state and loop

but I can open Fastboot Mode

What should I do now

Please help me

thank you in advance
[OnePlus 9RT] Dumaxa:
If Now i have Lahaina showed - how to fix this name to martini on OOS13.1?
[OnePlus 9RT] pintosarker00:
You can follow this video. Step by step.

1. Enable USB debugging.

2. Unlock bootloader

3. Install "Global ROM'
[OnePlus 9RT] penguinus:
If I understood correctly, you installed Lineage 20 over oos 13. Then I recommend you to use oos v13 to go back. Versions in first post here are old, based on android 11, see this link for updated versions. Especially here is latest 13 version f.15 and here is 13.1.0.500 that is 13.1.

Boot to bootloader/fastboot mode, start install.bat and follow the instructions on screen.
[OnePlus 9RT] 9rtflash:
please help oneplus 9rt doesn't react on the command: fastboot flashing unlock

ColorOS Version 14
[OnePlus 9RT] Valdem:
please check what reporting version of fastboot

fastboot --version

You need to run this command in command line window opened in the firmware folder.

If it use builted-in version of fastboot it should report 32...

If something else - most probably it use system wide installation of fastboot. In this case you need to upgrade you system fastboot binary or just uninstall it to force use built in version.

You cat get most resent version of fastboot by the next link
[OnePlus 9RT] miky03:
Hi i uninstalled the external one still same behavior
[OnePlus 9RT] Valdem:
please check your PM. I prefer do not spam in main topic. We will post our conclusions here.
[OnePlus 9RT] lukhach0:
I followed ur instruction and so far so good, just one more thing i want to know, if my device havent been rooted yet, it will can normaly get ota update like indian ver right ?
[OnePlus 9RT] ThingVn:
In my opinion, probably not, because from A.03 OTA update to A.04 is faulty. So I think the ability to update OTA is very difficult. Is it possible to wait for the update via fastboot shared as above, or the official rom from the Oneplus homepage?
[OnePlus 9RT] lukhach0:
I will wait for next update to check it. IMO oneplus doesnt care too much about 9rt so official rom maybe take very long time to release.
[OnePlus 9RT] Valdem:
yes it should. Especially if you lock bootloader. But even with unlocked bootloader it will work if you doesn't change system partitions content.
[OnePlus 9RT] Valdem:
This is not work only for first initial version which was released in Telegram group. For my release it work. However now my release is latest available version A04
[OnePlus 9RT] Gaku-o:
Please teach me how to re-lock bootloader after install oos11.
[OnePlus 9RT] Valdem:
1. reboot device into bootloader

2. run fastboot flashing lock

3. device will cleanup all user data and boot to initial setup wizard.

Done
[OnePlus 9RT] Barabaz:
is this better than the ColorOS?
[OnePlus 9RT] borg79:
Check this out : https://docs.microsoft.com/en-us/wi...all/the-testsigning-boot-configuration-option
[OnePlus 9RT] ThingVn:
There is a new update A.05. I can't do an OTA update either. I look forward to your fastboot update, thanks
[OnePlus 9RT] lukhach0:
For me its run smoothly, i get ota update. Maybe because my device unrooted and bootloader relock after flash u should try with this. Goodluck.

P/s: One small issue its showing wrong model name.
[OnePlus 9RT] ThingVn:
did you relock the bootloader?
[OnePlus 9RT] lukhach0:
After flash this Rom my phone automaticly relock bootloader
[OnePlus 9RT] ThingVn:
Thank you. Maybe I should try locking the bootloader again
[OnePlus 9RT] Valdem:
It is not an issue, it is a feature. This the only one known issue during conversion from ColorOS to OxygenOS. It shows weird model name in settings. No it shows correct model name for devices with OxygenOS.
[OnePlus 9RT] Valdem:
Please, if some one is able to download or extract OTA zip file with A.05 update. Upload it somewhere and send link to me.

I will try to prepare full A.05 fastboot version or ROM. Because my device is in locked state and used as daily driver by my wife now.

You help will be highly appreciated.
[OnePlus 9RT] ThingVn:
I was shared by a friend on telegram, and I uploaded it

3fd91f00a4a9ca2640acb6541c45ca0add31b418.zip

drive.google.com
[OnePlus 9RT] Barabaz:
Hi is 5G really not available?
[OnePlus 9RT] ThingVn:
You try to make a new sim
[OnePlus 9RT] EduFaol:
Has anyone upgraded to A.05? Here it appeared but when trying it gives an error and asks to restart the device, I do but it does not solve, I believe it is due to root.
[OnePlus 9RT] Barabaz:
What do you mean? ejecting it from the sim tray then reconnect? If that's so.. I already have done it with no success.. still no 5G
[OnePlus 9RT] ThingVn:
no, I mean you should contact the supplier to exchange a new sim embryo
[OnePlus 9RT] ThingVn:
You should cancel root and relock bootloader to be able to update OTA
[OnePlus 9RT] EduFaol:
Could you tell me what command to lock the bootloader?
[OnePlus 9RT] Barabaz:
I had 5G enabled when I was using colorOS12 but after flashing to this ROM it disappeared. So replacing the sim won't fix it.
[OnePlus 9RT] ThingVn:
1. reboot device into bootloader

2. run "fastboot flashing lock"

3. device will cleanup all user data and boot to initial setup wizard.
[OnePlus 9RT] EduFaol:
Thank you very much
[OnePlus 9RT] EduFaol:
(a imagem atual (inicialização/recuperação) foi destruída e não pode

inicializar)

bloqueei o bootloader e apareceu essa mensagem, se eu desbloquear o sistema inicia sem problema mas bloqueando esse erro.
[OnePlus 9RT] lukhach0:
Its happen with 9 pro also when switch from color to oxygen. Try this "*#*#4636#*#* and choose phone information and then option start with with NR/LTE/TDSCDMA/GSM/WCDMA" or search "No 5g after switching to oxygenos" on xda u will get some other solution.
[OnePlus 9RT] Barabaz:
*#*#4636#*#* no longer works. I can't find any threads with solutions too. I tried installing forceLTE but settings does not stick after reboot.. hopefully OP can help
[OnePlus 9RT] ntt.cr7:
How can i boot into Fastboot mode on my 9RT? I cann't see Advance Mode to reboot into Fastboot mode :(
[OnePlus 9RT] EduFaol:
This one in the image is the FastbootD mode, to restart in Bootloader mode, you must restart by holding the volume button + and - that it enters.

￼

￼
[OnePlus 9RT] EduFaol:
I solved by putting it in bootloader mode, extracting the Indian Rom posted here and clicking on Flash-all.bat, I believe that solves it with yours.
[OnePlus 9RT] uragol3042@gmail.com:
He doesn’t go anywhere with me at all. Brick. The computer sees the phone only in this way.
[OnePlus 9RT] Valdem:
there is no official MSMDowload Tool firmwares for this devices. However I found next link during my research. But some guy posted feedback that this guy can't help with this firmwares.
[OnePlus 9RT] hungreo011:
Hi. I tried relock bootloader but got error. It said that boot was destroyed and cant boot. Now after try restart (power + volume up down) and get into fastboot and flash oos again. Please help.
[OnePlus 9RT] EduFaol:
There must be a simpler way but I solved it as follows, I unlocked it again, I installed the A.04 rom again, I updated it to A.05 and I blocked the bootloader.
[OnePlus 9RT] Valdem:
This message means that you system files was modified. Most probably device is rooted or as some users reports that they have received already unlocked devices with modified firmware. In both cases bootloader can't be locked properly. You need to unlock it again. Flash valid firmware and only after this you will be able to lock bootloader properly.
[OnePlus 9RT] Barabaz:
OP. Do you have any idea how to fix this 5G issue after converting from colorOS to this ROM??
[OnePlus 9RT] Valdem:
This is obviously the wrong approach. If your device bootloader is locked, OTA should be installable without issues. You can have some issues with device misconfiguration which doesn't allow you to start update process, but "locked" bootloader prevents user from changing critical system data on device which is updatable by OTA.
[OnePlus 9RT] EduFaol:
In A.04 when blocking the bootloader after restarting it gave a message that the boot had been corrupted, I tried some commands and nothing worked, so I unlocked it again I went up the system I updated to A.05 then restarted and blocked the bootloader again. today everything is working and without needing root. it was the only way I could solve to recover the boot, certainly there must be a simpler way but I couldn't. I believe the boot corrupted because of root, not sure if that was it, just a hypothesis.
[OnePlus 9RT] shawn4sp:
Is there a way to COMPLETELY backup before lock the bootloader, so that I can restore my user data/apps/photos/storage afterwards? Thank you!

I believe lock or unlock bootloader would erase all the data.

I found this a hard way. I unlocked my bootloader to install A.03, but found all my data were erased and took me one day to setup my phone again. Fortunately, my photos were recovered from cloud.
[OnePlus 9RT] Valdem:
I have added the A.05 version of firmware to OP. It can be used for migration from ColorOS or update from previous versions of OxygenOS.
[OnePlus 9RT] EduFaol:
It's doing a great job, just getting rid of the Color OS that had 2 languages there and going to the official Oneplus interface and everything working, was a great help.
[OnePlus 9RT] Barabaz:
have you had issues with 5G band after migrating from colorOS to OxygenOS?
[OnePlus 9RT] Gaku-o:
Is VOLTE available with this rom?
[OnePlus 9RT] shawn4sp:
No. See my post

https://xdaforums.com/t/rom-indian-oxygenos11.4390243/page-6#post-86502489
[OnePlus 9RT] Valdem:
I have no way to test 5G. Modem firmwares are different in COS and OOS. As an option you can try to use modem firmware from COS when you flash OOS. However I couldn't guaranty that this will work.
[OnePlus 9RT] EduFaol:
Here, 5G is not available for commercialization yet, so I don't even stress about it.
[OnePlus 9RT] Barabaz:
Can you provide me an instruction to do that? I'll give you guys an update if it works or not
[OnePlus 9RT] Barabaz:
We're on an entire different locations hence I badly need it
[OnePlus 9RT] jamesjerss:
Global convert guide
[OnePlus 9RT] smjunaid:
thanks for providing such a detailed guide and resources.. i flashed the rom 03 successfully and unlocked the bootloader. i was unable to install the ota updates as the bootloader was locked still.

when i try to lock the bootloader, the device gets brick and fails to go into fastboot mode. and i get a display the current image has been destroyed.. i somehow managed to flash back to a.03 ..

can anyone give me any leads how to lock the bootloader safely and able to get OTAz
[OnePlus 9RT] ThingVn:
Relock

1. reboot device into bootloader

2. run "fastboot flashing lock"

3. device will cleanup all user data and boot to initial setup wizard.

Done
[OnePlus 9RT] smjunaid:
i tried to run fastboot flashing lock

after that my device shows the attached screen
[OnePlus 9RT] ThingVn:
Have you ever Rooted? If you are rooted, the system may have problems!

You try to flash all again, let the phone boot and use normally, then use fastboot to relock
[OnePlus 9RT] Barabaz:
Is this really Global? If so maybe this can fix the 5G band issue
[OnePlus 9RT] ThingVn:
The official homepage of Oneplus is not available yet. This is also an Indian fastboot rom
[OnePlus 9RT] Barabaz:
Thanks! I just hope that someone can figure out how to fix that minor issue.
[OnePlus 9RT] ThingVn:
I am also using 9rt chinese version and I also used fasboot rom. I don't have the same problem as you.

It might be because before you flashed via OxygenOS rom you installed an update of ColorOS and it happens this problem!

I hope everyone can help you out of this situation
[OnePlus 9RT] smjunaid:
no my phone is not rooted.. never tried to root.. i think i should manually upgrade my phone until the MSM tools are available. because if i brick it. there are no MSM tools available for 9rt to fixed.. or am i missing something
[OnePlus 9RT] smjunaid:
have you relocked your bootloader and received the ota successfully ?
[OnePlus 9RT] ThingVn:
Yes, I did it and it's done
[OnePlus 9RT] EduFaol:
This happened to me, installing A.04 again lets the system start, update to A 05 and then block the bootloader that works. or else install the A.05 as it is available here on the forum for download and block the bootloader.
[OnePlus 9RT] shawn4sp:
Hi experts,

Is this question too easy or too hard to answer? I am new and just want to have a feeling whether it is possible or worth to lock the bootloader. Thanks!

Or maybe I would stuck at the low version forever..

I see thumbs up from others 5star02707 and bonez56, does that mean other people are also interested in this topic and could be useful?

Last time I tried google backup and recover, then found many apps settings were missing and still need to backup folders by myself etc which is tedious.
[OnePlus 9RT] EduFaol:
If you block the bootloader it will make updates via OTA without having to backup. your device will be the same as it left it before the update. If you don't want to block, there's a topic explaining how to update by downloading the most current Rom, extracting and just clicking on a flash-all.sh file with a smartphone in Bootloader mode. your device will update without any problem.