[Guide] Convert to Global [WIP]

matteosaeed

Senior Member
Oct 3, 2012
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*** Use this at your very own risk.

***Backup your persist.img. There is a guide to fix it if needed.

*** Backup your working modem. Sometimes it is as simple as restoring it if you lose signal.

*** When flashing, you must understand the difference between fastboot and fastbootd to avoid flashing errors.

*** Backup your files in a safe place.

*** Some users are reporting that the whole thing is not working and going on a blame streak. So if you're not quite ready, please don't attempt this.




Basic Instructions: "I will test again since some users are losing signal after flashing". There is a debate whether msm and update the tmobile firmware, or flash the global. Again this is a WIP.

MSM. Here is the thread.
Unlock bootloader or re-unlock bootloader ... Enable OEM Unlock in developer options. flash token.
Fastboot
Code:
fastboot flash cust-unlock <unlock_token.bin>
Code:
fastboot oem unlock
and now your bootloader is unlocked.

Here is the t-mobile article for the 6t. same instructions for the 8 if you're new to this.

NEXT:

Link to fastboot thread
https://forum.xda-developers.com/oneplus-8/how-to/rom-stock-fastboot-roms-oneplus-8-t4084629

Download the global fastboot rom from here.

Unzip and flash all.

Link to twrp thread:
https://forum.xda-developers.com/oneplus-8/development/recovery-unofficial-twrp-oneplus-8-t4101315

If you want to root.
Boot into twrp or flash the twrp installer. TWRP 3.3.1-10 Test by mauronofrio and or TWRP 3.3.1-10 Test Installer by mauronofrio "newer ones may work"

After booting, you can flash magisk with-in twrp and you're rooted.

I have used oxygen updater to update the firmware while rooted. After the local install, open magisk and flash on the inactive slot.
---------------

If you ever want to revert, use the msm tool. Here is the thread.
https://forum.xda-developers.com/oneplus-8/how-to/op8-unbrick-tool-to-restore-device-to-t4093043

---------
Old information from the old thread is below, if you want to use it only for reference or for backing up the FP persist

---------------

Old Instructions
Here we go .....
This is fairly new and hasn't been tested so, proceed with caution. There are more knowledgable people here. This was just tested quick and it worked.

Requirements
1-Be on T-mobile firmware and update to the latest version. If you are bootloader unlocked, you mean not be able to take OTA's and you may need to reflash with MSM and update, then unlock the bootloader again. Thread Thanks @Some_Random_Username

2 - Unlock your bootloader.

3- --! IMPORTANT: Make a TWRP backup of your MODEM because we'll restore that later, why? because t-mobile sim doesn't work on the Global Modem. You can also back everything up in TWRP just in case.
If you have OTG, make the backup there so it is safe. You can restore the modem through TWRP with the OTG.

4-Backup your persist. Otherwise you may lose the fingerprint.
You'll need root.
Code:
adb shell
HTML:
su
Code:
dd if=/dev/block/bootdevice/by-name/persist of=/sdcard/persist.img
Then
Code:
adb pull sdcard/persist.img
Then copy it from from Sdcard to a safe place



*** You may lose signal again if you update the global version. It is a WIP but keep your modem backed up!

With all the above:
It is simple. Download the global firmware and flash it through fastboot. Here is the thread
.. I tested with "10.5.5-GLOBAL-OnePlus8Oxygen_15.O.14" Thanks @mauronofrio

  • Reboot to fastboot
  • Unzip and flash-all
  • It will reboot to the global firmware. "Now you won't get cellphone signal"
  • Skip the setup and reboot to fastboot.
  • reboot to twrp, do not flash it.
    Code:
    fastboot boot twrp.img
    link to twrp thread. . I used TWRP 3.3.1-2 Test by @mauronofrio
  • plug in the OTG or locate the backup and Restore the Modem" to get signal
  • Reboot and you'll have signal.

To root. you can flash the patched boot located in the sourceforge folder " Patched-Stock-Boot" on this thread
Code:
fastboot flash boot filename.img
You can also flash magisk in twrp. I prefer the patched boot.

Bonus: I am running the Nolimit magisk rom Thanks @xXx
https://forum.xda-developers.com/on...gisk-rom-xxx-nolimits-11-0-speed-ram-t4088609

Thanks @Some_Ghost for testing.
 
Last edited:

rjp0615

Senior Member
May 28, 2010
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Galloway, OH
Here we go .....
This is fairly new and hasn't been tested so, proceed with caution. There are more knowledgable people here. This was just tested quick and it worked.

Requirements
1-Be on T-mobile firmware and update to the latest version. If you are bootloader unlocked, you mean not be able to take OTA's and you may need to reflash with MSM and update, then unlock the bootloader again. Thread Thanks @Some_Random_Username

2 - Unlock your bootloader.

3- --! IMPORTANT: Make a TWRP backup of your MODEM because we'll restore that later, why? because t-mobile sim doesn't work on the Global Modem. You can also back everything up in TWRP just in case.
If you have OTG, make the backup there so it is safe. You can restore the modem through TWRP with the OTG.

4-Backup your persist. Otherwise you may lose the fingerprint.

*** You may lose signal again if you update the global version. It is a WIP but keep your modem backed up!

With all the above:
It is simple. Download the global firmware and flash it through fastboot. Here is the thread
.. I tested with "10.5.5-GLOBAL-OnePlus8Oxygen_15.O.14" Thanks @mauronofrio

  • Reboot to fastboot
  • Unzip and flash-all
  • It will reboot to the global firmware. "Now you won't get cellphone signal"
  • Skip the setup and reboot to fastboot.
  • reboot to twrp, do not flash it.
    Code:
    fastboot boot twrp.img
    link to twrp thread. . I used TWRP 3.3.1-2 Test by @mauronofrio
  • plug in the OTG or locate the backup and Restore the Modem" to get signal
  • Reboot and you'll have signal.

To root. you can flash the patched boot located in the sourceforge folder " Patched-Stock-Boot" on this thread
Code:
fastboot flash boot filename.img
You can also flash magisk in twrp. I prefer the patched boot.

Bonus: I am running the Nolimit magisk rom Thanks @xXx
https://forum.xda-developers.com/on...gisk-rom-xxx-nolimits-11-0-speed-ram-t4088609

Thanks @Some_Ghost for testing.
Am I understanding correctly, we will have to re-flash the modem after EVERY update?
 

Some_Ghost

Senior Member
Nov 6, 2019
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0
delete

---------- Post added at 02:38 AM ---------- Previous post was at 02:32 AM ----------

The EU modem dont fix it I just need tmobile modem if anyone can can someone give be the modem either tarp backup or .img file so I can use data
If you flash your modem backup with Euro firm it sticks throughout updates so far... It didn't work for me on global. You still need to restore your modem backup on either firmwares. Global so far modem doesn't stick after updates, euro so far, it stays after updates.
 
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ecompton59

Senior Member
Jan 9, 2015
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delete

---------- Post added at 02:38 AM ---------- Previous post was at 02:32 AM ----------



If you flash your modem backup with Euro firm it sticks throughout updates so far... It didn't work for me on global. You still need to restore your modem backup on either firmwares. Global so far modem doesn't stick after updates, euro so far, it stays after updates.
I fixed it with ota if you flash global do the enable and and dev settings I waited to install magisk. Ayer first boot put ota for global and it works because ota has modem in it and fastboot can't flash modem yet with bat file but I have no issues I have global modem and global ROM and from here on ota will work no need for modem
 

Vio281

Senior Member
May 14, 2020
93
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8
not really converting to Global then? this is just so you can use dev ROM, but since DEV rom hasnt come about there really is no reason to do this.
 

Some_Ghost

Senior Member
Nov 6, 2019
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I fixed it with ota if you flash global do the enable and and dev settings I waited to install magisk. Ayer first boot put ota for global and it works because ota has modem in it and fastboot can't flash modem yet with bat file but I have no issues I have global modem and global ROM and from here on ota will work no need for modem
I will try this thanks ??
 

Vio281

Senior Member
May 14, 2020
93
13
8
What? He used global ROM. Not a DEV ROM.
Thats what I'm saying, this is to flash rom, it not necessarily converting the phone to a global phone since it still need Tmobile Modem bin file in order to be function as a phone. If you take the phone outside the U.S it questionable if it works, that is why I say this is only for Dev Rom and in this case stock global rom but it is not a global phone.
 

matteosaeed

Senior Member
Oct 3, 2012
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@joemossjr :p :p :p

Thats what I'm saying, this is to flash rom, it not necessarily converting the phone to a global phone since it still need Tmobile Modem bin file in order to be function as a phone. If you take the phone outside the U.S it questionable if it works, that is why I say this is only for Dev Rom and in this case stock global rom but it is not a global phone.
Well check @ecompton59 's response. He was able to get things working.

The modem does work, just there is an issue with the fastboot flashing the modems. The TWRP restore of the modem is to get cell signal right away.

Here is what I did:
  • After I did what is in the first post in the thread:
  • I used oxygen updater to download the EU update and flashed it via "Local Upgrade" @Some_Ghost tested that as well.
  • There is signal. I believe that it may have flashed the modem "maybe", unlike fastboot.
  • While I was on the EU version, I downloaded the update for the global, and did a "Local Upgrade" again, and got signal.
  • I did all of this with Magisk being installed and after each "local upgrade, before reboot" I install Magisk on the "inactive slot, ota".

Technically speaking and don't quote me 100%, the first flash to the global is what gives issues with the sim, but that's the way to get the ability to do "local upgrade" because it is disabled on the t-mobile firmware.

Theoretically and I haven't tested.
Unlock bootloader >> Flash global "won't flash everything properly" = no signal
Global to another global or EU update >> will flash the modem >> signal will work "as it will properly flash everything"
 

Vio281

Senior Member
May 14, 2020
93
13
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@joemossjr :p :p :p



Well check @ecompton59 's response. He was able to get things working.

The modem does work, just there is an issue with the fastboot flashing the modems. The TWRP restore of the modem is to get cell signal right away.

Here is what I did:
  • After I did what is in the first post in the thread:
  • I used oxygen updater to download the EU update and flashed it via "Local Upgrade" @Some_Ghost tested that as well.
  • There is signal. I believe that it may have flashed the modem "maybe", unlike fastboot.
  • While I was on the EU version, I downloaded the update for the global, and did a "Local Upgrade" again, and got signal.
  • I did all of this with Magisk being installed and after each "local upgrade, before reboot" I install Magisk on the "inactive slot, ota".

Technically speaking and don't quote me 100%, the first flash to the global is what gives issues with the sim, but that's the way to get the ability to do "local upgrade" because it is disabled on the t-mobile firmware.

Theoretically and I haven't tested.
Unlock bootloader >> Flash global "won't flash everything properly" = no signal
Global to another global or EU update >> will flash the modem >> signal will work "as it will properly flash everything"

again, this does not make it a global sim unlock phone, you are flashing a previous Tmobile Modem on top of a Global rom.
 

bluemoel

Member
May 15, 2015
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4
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It at least we can run different firmwares on T-Mobile. You could try the global msm on T-Mobile and report back. As being sim unlocked depends on the bands enabled in other countries but should work with any sim.
is there different functionality between the tmobile modem and global modem firmware? I flashed the global rom and am using that with tmobile modem flashed through twrp. I haven't done a local update yet to get the global modem. if I do, what is the difference running that vs the tmobile modem? im in seattle using tmobile anyway.... would I see a difference in anything? speed? I had updated to the tmobile ota right before I flashed, they supposedly updated something with the modem in that update. im just wondering if there is a benefit to using the global modem or not. I definitely see the benefit in using he global rom though....lol
 

Some_Ghost

Senior Member
Nov 6, 2019
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is there different functionality between the tmobile modem and global modem firmware? I flashed the global rom and am using that with tmobile modem flashed through twrp. I haven't done a local update yet to get the global modem. if I do, what is the difference running that vs the tmobile modem? im in seattle using tmobile anyway.... would I see a difference in anything? speed? I had updated to the tmobile ota right before I flashed, they supposedly updated something with the modem in that update. im just wondering if there is a benefit to using the global modem or not. I definitely see the benefit in using he global rom though....lol
you'll be fine, my signal hasn't changed since flashing it remained the same as far as I can tell

---------- Post added at 12:34 PM ---------- Previous post was at 12:30 PM ----------

again, this does not make it a global sim unlock phone, you are flashing a previous Tmobile Modem on top of a Global rom.
Be happy that people actually take the time to experiment and work on things like this for the community so we can root and run different firmwares, kernels, and recoveries etc. At the least we aren't stuck on TMO firmware with lack of updates and missing features and as far as we can tell everything is working and odds are you aren't going to be using a T-Mobile SIM when going out of country anyway. Any issues will be ironed out when we cross that path I am sure ??
 
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