[Guide] Unlocking Bootloader and gaining root on the A90 5G

Search This thread

triggz881

Member
Mar 1, 2017
15
23
Notes: This trips KNOX so you will void your warranty, read all the steps carefully before beginning, flashing can be dangerous if you do it wrong. Don't blame me if you brick your device.
Backup all of your data and settings before starting as you will need to reset to factory defaults during this process.
With that being said, the process is relatively straightforward and easy.
PS: my device is the A908B, there is also an A908N if anyone wants to test on that be my guest.

Needed:
ADB
SamFirm
Odin
Magisk Manager


Step 1 - Downloading your firmware.

Go to SamMobile SM-A908B
Find the correct firmware for your device according to country and operator.
Note: You can use generic country firmware instead, this will remove carrier added software and limitations but may remove features and disables OTA updates.
Note the 'product code'.
Now open SamFirm.
Type SM-A908B for model
In the region box type the product code you noted earlier.
Click Check Updates.
When it has found the firmware, make sure decrypt automatically is checked and then click download rom.
The firmware is around 4gb.

Part 2 - Unlocking the Bootloader

Go to settings > about phone > software information. Hit build number a bunch of times until you activate developer options.
Go back to settings > developer options
Enable OEM unlocking
Enable USB debugging
Turn off the phone
Hold volume up and volume down whilst inserting the USB cable
This should take you to the bootloader unlock screen.
Long press Volume up to unlock the bootloader.

Part 3 - Obtaining root

After SamFirm finished downloading the rom it should have extracted it into 5 tar files.
Copy the tar file beginning with AP to your device.
Download Magisk Manager on the device and install.
Press Install on Magisk Manager
Confirm the Install
Select the option 'select and patch file', then locate the APdjkfgrsdkfhgkjrg.tar.md5 on your device and select it.
Magisk will then patch the file and dump the patched version to your phone.
Copy the patched.tar to your PC
Reboot phone into download mode
Open Odin
For BL use the BL.tar.md5 file from stock firmware
For AP use the patched.tar file
For CP use the CP.tar.md5 file from stock firmware
For CSC use the CSC.tar.md5 file from stock firmware (not the CSC_HOME)
Press Start and wait for it to flash
After flashing, the phone will reset.
After initial setup, install magisk manager again.
Remove the USB cable and turn off the phone.
Turn on the phone by holding volume up and power, let go when you see the bootloader warning.
Open Magisk Manager Click Install.

Phone is now rooted.

Note: Powering on the device normally will disable root, you must hold volume up to power on the device to activate root.
 
Last edited:

triggz881

Member
Mar 1, 2017
15
23
Going to put a few hours into compiling twrp tonight but this might take me forever, I'm really busy with work and I got 2 kids too so free time is scarce. So feel free to have a go at it yourself.
 

Hunteres

Senior Member
Nov 4, 2010
1,081
198
Dublin
After root activation with the volume button start up will the root persist? Can the device be restarted without any hidden key?


Thank you
 
  • Like
Reactions: underdog_656

triggz881

Member
Mar 1, 2017
15
23
Yes the root persists, but every time you turn the phone off and back on again you will have to hold up to activate the root. Resetting the phone while root is enabled does not disable it though iirc.

More work done on twrp last night, nearly ready to attempt compiling.

Edit: So I made a device tree and compiled twrp fine. Unfortunately it needs a custom kernel to be able to boot. Working on this now.
 
Last edited:

triggz881

Member
Mar 1, 2017
15
23
No not really. I need to reach out to the twrp Devs of the S10 and see what modifications they did to theirs, but super busy at the moment. Sorry.
 
  • Like
Reactions: johnoponi

jasonc417

Member
Jul 4, 2014
27
1
Failure on Model SM-A9080 (China Version)

Today I did this on model SM-A9080 but unluckily failed, and the OS could not be loaded, with boot loop on the phone.

Really the specified TWRP should be developed.
 

Steveee101

New member
Oct 7, 2019
2
1
Ok so I made a lot of progress since last post. I'm compiling the kernel as I type. But the process takes a long time. If we are lucky it will boot twrp straight away if not I'll keep at it until I manage.

Hey - did you manage to get anywhere with this? If you'd like help, i'd be happy to get stuck in. Could you put the code on Github?
 

Tsunami_HD

New member
Mar 27, 2020
2
0
Hello,
I tried to root my phone today, and I followed every step exactly, but now I am stuck in a Boot Loop, after the Step of Flashing. Can someone help, or knows why this happened? Thank you.

---------- Post added at 07:48 PM ---------- Previous post was at 07:03 PM ----------

Okay I fixed it myself. The Problem was, I only Flashed the BL File. After that I flashed the other files one by one, did a Factory Reset in Recovery mode and now it worked! I even have root now.
 
Last edited:

xijaw

Senior Member
Aug 9, 2018
114
9
Xiaomi Poco F3
So why did you buy a Samsung.

I live in Australia and here we don't have a market like Europe and India. We only have couple of brands- Apple and Samsung.

---------- Post added at 01:31 PM ---------- Previous post was at 01:30 PM ----------

Lmao, true. He could of easily went for one plus etc..

And bullshit, Samsung ui is definitely top it's really nice.. just the notifications could be improved

Lets stick to the topic and get the damn custom rom built. Aren't there any devs who willing to take A90 as a project ?
 

MarcTR

New member
Oct 19, 2019
3
0
Hello please can someone help me root this phone, i have followed the steps but i just seem to be missing something so can someone take me through this step by step for a dumb person like myself lol?
At first i was struggling with part one of this tutorial but once i updated samfirm i was able to download it without a problem. moving over to the last step which is using odin to do its thing with the tar files and upon finishing where it should reboot it is stuck into a boot loop saying "this phone is not running samsungs offical software", i am not sure what i am missing and i am able to fix the phone without any problems but no root is achieved
 
Last edited:

Top Liked Posts

  • There are no posts matching your filters.
  • 4
    Yes the root persists, but every time you turn the phone off and back on again you will have to hold up to activate the root. Resetting the phone while root is enabled does not disable it though iirc.

    More work done on twrp last night, nearly ready to attempt compiling.

    Edit: So I made a device tree and compiled twrp fine. Unfortunately it needs a custom kernel to be able to boot. Working on this now.
    3
    Notes: This trips KNOX so you will void your warranty, read all the steps carefully before beginning, flashing can be dangerous if you do it wrong. Don't blame me if you brick your device.
    Backup all of your data and settings before starting as you will need to reset to factory defaults during this process.
    With that being said, the process is relatively straightforward and easy.
    PS: my device is the A908B, there is also an A908N if anyone wants to test on that be my guest.

    Needed:
    ADB
    SamFirm
    Odin
    Magisk Manager


    Step 1 - Downloading your firmware.

    Go to SamMobile SM-A908B
    Find the correct firmware for your device according to country and operator.
    Note: You can use generic country firmware instead, this will remove carrier added software and limitations but may remove features and disables OTA updates.
    Note the 'product code'.
    Now open SamFirm.
    Type SM-A908B for model
    In the region box type the product code you noted earlier.
    Click Check Updates.
    When it has found the firmware, make sure decrypt automatically is checked and then click download rom.
    The firmware is around 4gb.

    Part 2 - Unlocking the Bootloader

    Go to settings > about phone > software information. Hit build number a bunch of times until you activate developer options.
    Go back to settings > developer options
    Enable OEM unlocking
    Enable USB debugging
    Turn off the phone
    Hold volume up and volume down whilst inserting the USB cable
    This should take you to the bootloader unlock screen.
    Long press Volume up to unlock the bootloader.

    Part 3 - Obtaining root

    After SamFirm finished downloading the rom it should have extracted it into 5 tar files.
    Copy the tar file beginning with AP to your device.
    Download Magisk Manager on the device and install.
    Press Install on Magisk Manager
    Confirm the Install
    Select the option 'select and patch file', then locate the APdjkfgrsdkfhgkjrg.tar.md5 on your device and select it.
    Magisk will then patch the file and dump the patched version to your phone.
    Copy the patched.tar to your PC
    Reboot phone into download mode
    Open Odin
    For BL use the BL.tar.md5 file from stock firmware
    For AP use the patched.tar file
    For CP use the CP.tar.md5 file from stock firmware
    For CSC use the CSC.tar.md5 file from stock firmware (not the CSC_HOME)
    Press Start and wait for it to flash
    After flashing, the phone will reset.
    After initial setup, install magisk manager again.
    Remove the USB cable and turn off the phone.
    Turn on the phone by holding volume up and power, let go when you see the bootloader warning.
    Open Magisk Manager Click Install.

    Phone is now rooted.

    Note: Powering on the device normally will disable root, you must hold volume up to power on the device to activate root.
    3
    Any further progress??

    Ok so I made a lot of progress since last post. I'm compiling the kernel as I type. But the process takes a long time. If we are lucky it will boot twrp straight away if not I'll keep at it until I manage.
    2
    Going to put a few hours into compiling twrp tonight but this might take me forever, I'm really busy with work and I got 2 kids too so free time is scarce. So feel free to have a go at it yourself.
    1
    Do we have a custom rom yet? Can't stand the samsung rom or whatever its called.

    So why did you buy a Samsung.