• Introducing XDA Computing: Discussion zones for Hardware, Software, and more!    Check it out!

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

Search This thread

buzzkill616

New member
Sep 20, 2010
3
1
Hi there,

Thanks for the detailed guide.

I just tried to enter Download mode on my AT&T S21 Ultra and when I select the "Reboot to Bootloader" it does a normal reboot.

Any help with this?
What am I doing wrong?
I was able to get to download mode by powering off the phone. Holding vol up and down then plugging in the USB with those two buttons held down. Of course make sure the usb is already pluged into the computer.
 
  • Like
Reactions: hitrek

hitrek

Member
Jul 28, 2013
13
13
In case it helps anyone, here's how I finally got it to work.

  1. Turn off the phone
  2. Wait 10s
  3. Hold both Volume UP + DOWN
  4. Plug into USB C cable - attached to Windows *
  5. Keep holding key until the first blue multilingual screen shows up
  6. Let go, and the phone automatically enters into Download Mode
* I had ODIN running during this step - don't know if it makes a difference or not.

Also if you do step 4 before 5, in my case just plugging into USB cable would restart the phone.
 

death365

Senior Member
Screenshot_20210607-051028_Software update.jpg
 

wolfu11

Senior Member
Jan 26, 2013
630
410
Minneapolis
In case it helps anyone, here's how I finally got it to work.

  1. Turn off the phone
  2. Wait 10s
  3. Hold both Volume UP + DOWN
  4. Plug into USB C cable - attached to Windows *
  5. Keep holding key until the first blue multilingual screen shows up
  6. Let go, and the phone automatically enters into Download Mode
* I had ODIN running during this step - don't know if it makes a difference or not.

Also if you do step 4 before 5, in my case just plugging into USB cable would restart the phone.
.
 
Last edited:

Ascertion

Senior Member
Mar 29, 2012
3,487
1,506
Thanks this worked great on my Galaxy S21 Ultra TMobile variant.

However powering into download mode was vol up + vol down from a powered-down state. OP instructs users to hold Vol down + power.

Also there was no USER DATA attachment, you can leave that blank. I also used the non-home CSC file and it worked fine. Otherwise the rest of the instructions were good.

I can finally uninstall Facebook now.

Thanks!
 

spydc

Senior Member
Jun 23, 2007
142
17
Hi guys. I have an At&T (ATT) S21 Ultra. I want to flash unlock firmware but i'm concerned I will lose Wifi Calling and VOLTE. Can anyone explain how to flash the S21 ultra firmware while keeping wifi calling. I also don't even mind keeping the ATT bloat. I just want to be able to get unlocked version of the updates. Lastly, if I wanted to go back to fully stock ATT S21 Ultra firmware, is that possible or will I be stuck?
 

bam654

Senior Member
Jun 6, 2013
150
27
Does anyone have the stocker Verizon firmware? If I want to flash the stock Verizon firmware do I flash it in the same way I flashed the unlocked firmware?
 

BBucket

New member
Jun 19, 2021
1
0
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.
I have a TMobile S21.

This is the first time I've flashed an Android phone that wasn't an OTA update, so I was nervous. I had also seen a couple of video on this process for the S21, going from carrier version to factory. Step 5 says to use the HOME CSC, but I forgot that, as the videos had said to use the regular CSC. Because they said HOME was if you wanted to do a dirty upgrade keeping your settings. However I see in the steps here nonetheless it says this process would do a factory reset. What is the difference between HOME and regular CSC?

So my question is what is the difference between the HOME and regular CSC if both perform a factory reset. Should I reinstall the TMobile firmware and then reflash with the HOME version or regular version of that? Also the TMobile has USERDATA in it's firmware. The TMobile firmware I have I got thru Frija.

Only thing so far I've noticed is neither the Samsung Dialer nor the Google Phone apps say HD or HD+ on the calls anymore, but the phone I call into do. I don't know what codec if any may have been lost or if this is just a "feature" of the factory version that it doesn't show HD or HD+
 

jhunkab

Senior Member
I have a TMobile S21.

This is the first time I've flashed an Android phone that wasn't an OTA update, so I was nervous. I had also seen a couple of video on this process for the S21, going from carrier version to factory. Step 5 says to use the HOME CSC, but I forgot that, as the videos had said to use the regular CSC. Because they said HOME was if you wanted to do a dirty upgrade keeping your settings. However I see in the steps here nonetheless it says this process would do a factory reset. What is the difference between HOME and regular CSC?

So my question is what is the difference between the HOME and regular CSC if both perform a factory reset. Should I reinstall the TMobile firmware and then reflash with the HOME version or regular version of that? Also the TMobile has USERDATA in it's firmware. The TMobile firmware I have I got thru Frija.

Only thing so far I've noticed is neither the Samsung Dialer nor the Google Phone apps say HD or HD+ on the calls anymore, but the phone I call into do. I don't know what codec if any may have been lost or if this is just a "feature" of the factory version that it doesn't show HD or HD+
 

ragooriski

New member
Sep 2, 2018
1
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?
 
  • Like
Reactions: lonewolfdaddy

zunaidahmed

New member
Dec 2, 2013
4
0
Can someone confirm if this firmware works on the HK version? I am moving to the states and I want Samsung pay to work properly, so a US firmware would be needed, thx in advanced
 

kelv_awesome

Member
Jun 14, 2014
9
1
Hi,

This is the first time I'm trying to update Android phone manually. Reason is I'm from Malaysia and I imported the device from US as I prefer the snapdragon chip. However I found that I'm not able to update my device using OTA and I'm stuck at May 1 update.

Below is my device info. I'm new to this, so first question is can I flash this U1 firmware and second question is can get OTA for future updates once I flash to U1?

Thank you.
 

Attachments

  • 16276048533645571350127318127053.jpg
    16276048533645571350127318127053.jpg
    1.6 MB · Views: 32

nixnixnixnix4

Senior Member
Mar 15, 2021
352
75
Hi,

This is the first time I'm trying to update Android phone manually. Reason is I'm from Malaysia and I imported the device from US as I prefer the snapdragon chip. However I found that I'm not able to update my device using OTA and I'm stuck at May 1 update.

Below is my device info. I'm new to this, so first question is can I flash this U1 firmware and second question is can get OTA for future updates once I flash to U1?

Thank you.
I wonder if temporarily connecting to a US VPN would solve your problem.
There are some free/freemium/trial ones that could be used for this.
 

Top Liked Posts

  • There are no posts matching your filters.
  • 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
    will this work with the T-Mobile version?
    This will work with any carrier branded version. It will entirely convert it from the carrier bloated version, to the U1 unlocked, Samsung version.
    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 -