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General Samsung S21, S21+, and S21 Ultra U1 Firmware (Links)

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cjegan2008

Senior Member
May 31, 2008
242
27
Tucson, AZ
After looking really hard ahead of launch for the U1 S21 Ultra Firmware using Samfirm and Frija, I couldn't find the US XAA firmware. Well I finally got a hold of it ahead of launch. You can use this firmware to flash any carrier branded S21, S21+, and S21 Ultra to U1 after receiving your device using Odin. Attached are the Google Drive links I've uploaded for your convenience. Links will be updated on a monthly basis for simplicity. Below is a simple guide on to flash this.

Step 1: Download patched Odin and Firmware for the model that corresponds to your device's model number
Patched Odin link:
Download patched Odin and your phones firmware to an area on your computer that will be easy to access.

If you do not have a program that can open rar files, then Winrar is a great program. Download link here

Step 2: Download Samsung Smart Switch and make a complete backup of your entire device. Data will be wiped during this process, so make sure you have a complete backup.
If Samsung Smart Switch says your device has an update, DO NOT UPDATE USING SMART SWITCH!
Windows Link here: https://www.samsung.com/global/download/smartswitchwin/

Step 3: Once your device is done backing up, Power off your device and put your device in download mode by pressing the Volume down button and power button at the same time. If you have done it correctly, your device should show this screen.
samsung-download-mode-note-10.jpg

Image Credit: Technastic.com

Step 4: Connect your device to your computer and open up Odin.

Step 5: Once Odin is opened, make sure your device is showing as connected, then select AP, and find your firmware file that you had extracted earlier, and select the one that says AP_(Your phones model), and do the same for every other one. So BL for BL, CP for CP, CSC for CSC, and USERDATA for USERDATA. Make sure you select the HOME CSC.

Step 6: Click start. It will start to flash your U1 Firmware. Take a Tea break or something. Once its finished, it will automatically reboot.

Step 7: Once device reboots, sign into your Gmail account you used previously, as well as your Samsung account. Once its at the home screen, restore the backup you made using Smart Switch and then once that completes, sign into all your apps. Your done. All OTA's now ill be XAA Samsung OTA's, not carrier branded ones.

Step 8: Profit>?


(S21 Firmware) SM-G991U1 Firmware - https://drive.google.com/file/d/1Vcwzg6FJxEw9G7OWob_Y7bgMzYKHijfG/view?usp=sharing
(S21+ 5G Firmware) SM-G996U1 Firmware - https://drive.google.com/file/d/198TEeuqGdxI_6JgyzvyQ4DyoMX5IGfRc/view?usp=sharing
(S21 Ultra Firmware) SM-G998U1 Firmware - https://drive.google.com/file/d/1xKTAURxnGZTXQLI4yRM39mo2zixslkHr/view?usp=sharing

Enjoy and Happy Flashing
Paypal Donation Link


Questions and Answers

Will this work for the Exynos version of the S21?
No The provided firmware files are for the Snapdragon version. This might be compatible with the HK Snapdragon version, but I am not sure.

Help, Odin won't flash, gives me an error.
Respond in the comments below, and I'm sure we can get this to work.

Will this unlock my phone from my carrier?

No. If your device is locked before you flash this, it will be locked after you flash it. This is to remove carrier bloat and ensure all further updates will come from Samsung instead of your carrier. If you flash it before you unlock, you can still unlock your device as normal.

I have bootloader unlocked my device, will this relock my bootloader?
Yes. This includes the V2 bootloader for the S21 series, and as a result, if you flash this, you will lose your unlock token.

Updated for May 2021 Security patches.
 
Last edited:
Feb 2, 2021
8
5
Hi,
I can not change my csc by flashing via odin, I noticed that it was a problem that happened to a lot of people, I tried to flash the XEF version (french unbranded version) but it does not work...
I wanted to know if I could flash this U1 firmware on my galaxy s21 exynos version and then reflash to a XEF version?
My phone is SFR/SFR,SFR/EUX/SFR, by flashing the XEF version it didn't change anything.
Any ideas?

EDIT: I noticed that we could no longer change the factory csc on samsungs, thanks Samsung...
 
Last edited:

cjegan2008

Senior Member
May 31, 2008
242
27
Tucson, AZ
This will not work with the exynos version. It's U1 snapdragon only.

Hi,
I can not change my csc by flashing via odin, I noticed that it was a problem that happened to a lot of people, I tried to flash the XEF version (french unbranded version) but it does not work...
I wanted to know if I could flash this U1 firmware on my galaxy s21 exynos version and then reflash to a XEF version?
My phone is SFR/SFR,SFR/EUX/SFR, by flashing the XEF version it didn't change anything.
Any ideas?

EDIT: I noticed that we could no longer change the factory csc on samsungs, thanks Samsung...
 

cjegan2008

Senior Member
May 31, 2008
242
27
Tucson, AZ
What benefit do we get from this version? Wondering whether is would give the ability to use dual SIM on AT&T...
It doesn't allow dual SIM in the US at all. One of the first things I looked for once my AT&T S21 Ultra was unlocked. Even flashing U1 firmware doesn't allow that. However, it does completely convert the phone to the Unlocked version of Samsung's firmware, so your updates won't come with AT&T bloatware, only Samsung apps.
 

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  • 1
    After looking really hard ahead of launch for the U1 S21 Ultra Firmware using Samfirm and Frija, I couldn't find the US XAA firmware. Well I finally got a hold of it ahead of launch. You can use this firmware to flash any carrier branded S21, S21+, and S21 Ultra to U1 after receiving your device using Odin. Attached are the Google Drive links I've uploaded for your convenience. Links will be updated on a monthly basis for simplicity. Below is a simple guide on to flash this.

    Step 1: Download patched Odin and Firmware for the model that corresponds to your device's model number
    Patched Odin link:
    Download patched Odin and your phones firmware to an area on your computer that will be easy to access.

    If you do not have a program that can open rar files, then Winrar is a great program. Download link here

    Step 2: Download Samsung Smart Switch and make a complete backup of your entire device. Data will be wiped during this process, so make sure you have a complete backup.
    If Samsung Smart Switch says your device has an update, DO NOT UPDATE USING SMART SWITCH!
    Windows Link here: https://www.samsung.com/global/download/smartswitchwin/

    Step 3: Once your device is done backing up, Power off your device and put your device in download mode by pressing the Volume down button and power button at the same time. If you have done it correctly, your device should show this screen.
    View attachment 5298505
    Image Credit: Technastic.com

    Step 4: Connect your device to your computer and open up Odin.

    Step 5: Once Odin is opened, make sure your device is showing as connected, then select AP, and find your firmware file that you had extracted earlier, and select the one that says AP_(Your phones model), and do the same for every other one. So BL for BL, CP for CP, CSC for CSC, and USERDATA for USERDATA. Make sure you select the HOME CSC.

    Step 6: Click start. It will start to flash your U1 Firmware. Take a Tea break or something. Once its finished, it will automatically reboot.

    Step 7: Once device reboots, sign into your Gmail account you used previously, as well as your Samsung account. Once its at the home screen, restore the backup you made using Smart Switch and then once that completes, sign into all your apps. Your done. All OTA's now ill be XAA Samsung OTA's, not carrier branded ones.

    Step 8: Profit>?


    (S21 Firmware) SM-G991U1 Firmware - https://drive.google.com/file/d/1Vcwzg6FJxEw9G7OWob_Y7bgMzYKHijfG/view?usp=sharing
    (S21+ 5G Firmware) SM-G996U1 Firmware - https://drive.google.com/file/d/198TEeuqGdxI_6JgyzvyQ4DyoMX5IGfRc/view?usp=sharing
    (S21 Ultra Firmware) SM-G998U1 Firmware - https://drive.google.com/file/d/1xKTAURxnGZTXQLI4yRM39mo2zixslkHr/view?usp=sharing

    Enjoy and Happy Flashing
    Paypal Donation Link


    Questions and Answers

    Will this work for the Exynos version of the S21?
    No The provided firmware files are for the Snapdragon version. This might be compatible with the HK Snapdragon version, but I am not sure.

    Help, Odin won't flash, gives me an error.
    Respond in the comments below, and I'm sure we can get this to work.

    Will this unlock my phone from my carrier?

    No. If your device is locked before you flash this, it will be locked after you flash it. This is to remove carrier bloat and ensure all further updates will come from Samsung instead of your carrier. If you flash it before you unlock, you can still unlock your device as normal.

    I have bootloader unlocked my device, will this relock my bootloader?
    Yes. This includes the V2 bootloader for the S21 series, and as a result, if you flash this, you will lose your unlock token.

    Updated for May 2021 Security patches.
    We can use stock odin software or only pacthed one?
  • 5
    After looking really hard ahead of launch for the U1 S21 Ultra Firmware using Samfirm and Frija, I couldn't find the US XAA firmware. Well I finally got a hold of it ahead of launch. You can use this firmware to flash any carrier branded S21, S21+, and S21 Ultra to U1 after receiving your device using Odin. Attached are the Google Drive links I've uploaded for your convenience. Links will be updated on a monthly basis for simplicity. Below is a simple guide on to flash this.

    Step 1: Download patched Odin and Firmware for the model that corresponds to your device's model number
    Patched Odin link:
    Download patched Odin and your phones firmware to an area on your computer that will be easy to access.

    If you do not have a program that can open rar files, then Winrar is a great program. Download link here

    Step 2: Download Samsung Smart Switch and make a complete backup of your entire device. Data will be wiped during this process, so make sure you have a complete backup.
    If Samsung Smart Switch says your device has an update, DO NOT UPDATE USING SMART SWITCH!
    Windows Link here: https://www.samsung.com/global/download/smartswitchwin/

    Step 3: Once your device is done backing up, Power off your device and put your device in download mode by pressing the Volume down button and power button at the same time. If you have done it correctly, your device should show this screen.
    samsung-download-mode-note-10.jpg

    Image Credit: Technastic.com

    Step 4: Connect your device to your computer and open up Odin.

    Step 5: Once Odin is opened, make sure your device is showing as connected, then select AP, and find your firmware file that you had extracted earlier, and select the one that says AP_(Your phones model), and do the same for every other one. So BL for BL, CP for CP, CSC for CSC, and USERDATA for USERDATA. Make sure you select the HOME CSC.

    Step 6: Click start. It will start to flash your U1 Firmware. Take a Tea break or something. Once its finished, it will automatically reboot.

    Step 7: Once device reboots, sign into your Gmail account you used previously, as well as your Samsung account. Once its at the home screen, restore the backup you made using Smart Switch and then once that completes, sign into all your apps. Your done. All OTA's now ill be XAA Samsung OTA's, not carrier branded ones.

    Step 8: Profit>?


    (S21 Firmware) SM-G991U1 Firmware - https://drive.google.com/file/d/1Vcwzg6FJxEw9G7OWob_Y7bgMzYKHijfG/view?usp=sharing
    (S21+ 5G Firmware) SM-G996U1 Firmware - https://drive.google.com/file/d/198TEeuqGdxI_6JgyzvyQ4DyoMX5IGfRc/view?usp=sharing
    (S21 Ultra Firmware) SM-G998U1 Firmware - https://drive.google.com/file/d/1xKTAURxnGZTXQLI4yRM39mo2zixslkHr/view?usp=sharing

    Enjoy and Happy Flashing
    Paypal Donation Link


    Questions and Answers

    Will this work for the Exynos version of the S21?
    No The provided firmware files are for the Snapdragon version. This might be compatible with the HK Snapdragon version, but I am not sure.

    Help, Odin won't flash, gives me an error.
    Respond in the comments below, and I'm sure we can get this to work.

    Will this unlock my phone from my carrier?

    No. If your device is locked before you flash this, it will be locked after you flash it. This is to remove carrier bloat and ensure all further updates will come from Samsung instead of your carrier. If you flash it before you unlock, you can still unlock your device as normal.

    I have bootloader unlocked my device, will this relock my bootloader?
    Yes. This includes the V2 bootloader for the S21 series, and as a result, if you flash this, you will lose your unlock token.

    Updated for May 2021 Security patches.
    1
    are these the QUALCOMM Versions?
    Yes. US U1 firmware
    1
    FYI - I found new firmware that includes February Security Patch for G998U1 - you can download it here: February Firmware for Galaxy S21 Ultra

    the firmware is for a region labeled as ACG (not sure who this is - but I do know that the firmware works on my ATT S21 Ultra with no problems)

    Hope this is helpful -
    1
    FYI - I found new firmware that includes February Security Patch for G998U1 - you can download it here: February Firmware for Galaxy S21 Ultra

    the firmware is for a region labeled as ACG (not sure who this is - but I do know that the firmware works on my ATT S21 Ultra with no problems)

    Hope this is helpful -
    Thanks!