Below you will discover how to root the Samsung Galaxy A90 SM-A908B using Magisk, and how to install Magisk Manager. Before you go forward with the tutorial on how to Root Samsung Galaxy A90 SM-A908B, please read all of the warnings below. Do not proceed if you do not want KNOX to be triggered or if you do not want your data to be erased.
Before going to root Samsung Galaxy A90 SM-A908B you need to take all your messages, photos, and apps from your current smartphone. This requires a backup that you then restore on your device after flashing or updating the firmware.
Most smartphones automatically make a backup in the background, in case something happens. But to make sure you take everything to your new device, you need a full backup.
1: Enable OEM unlock. To do so, go to Settings > Developer options and tap on OEM unlocking.
2: Go to Settings > About Phone > Software Information and quickly tap 7 times on Build Number to enable Developer Options. Go to Developer options and make sure that OEM unlocking is greyed out.
Now that the Samsung Galaxy A90 SM-A908B bootloader is successfully unlocked, you have to flash Magisk to your Samsung Galaxy A90 SM-A908B. This time around, Magisk lives in the recovery section, so every time you reboot your phone, you have to go through recovery if you want to have Magisk.
B. Patching Samsung Galaxy A90 SM-A908B Firmware & installing Magisk
1: Download the Samsung Galaxy A90 SM-A908B stock boot file from the given link and extract the file.
2: Copy and the .tar file and transfer it to the internal storage of your phone.
4: Open Magisk Manager and go to Install > Install > Select and Patch a file.
5: Navigate through the storage and select the extracted file. The file will be patched and the new version will be found under Internal Storage/Download/magisk_patched.tar.
6: Transfer the patched file to your computer.
7: Turn off your phone and boot your phone into download mode.
8: On Odin, click on AP and select the patched.tar file. Uncheck “Auto Reboot” and click on Install.
9: The tool will flash Magisk on your Samsung Galaxy A90 SM-A908B.
C: Boot Samsung Galaxy A90 SM-A908B with Magisk installed
1: Once Odin is finished with installing Magisk, press and hold the Volume Down + Power button to exit download mode.
2: Once the screen is off, quickly press the Volume Up + Power buttons at the same time. A bootloader warning will show up. Keep pressing the volume up button. The phone will enter the stock recovery mode.
3: Using the volume buttons in recovery, highlight Wipe data/factory reset and press the power button to confirm.
4: Now highlight and select the Reboot system now and quickly press the Volume Up + Power buttons at the same time. When the bootloader warning shows up again, release the buttons this time around.
The process above will enable root permission on Samsung Galaxy A90 SM-A908B and will also install Magisk Manager. This is the app that you have to use to control root functions and to download and install different modules.
All you need to remember is the bootup procedure, and what you need to press if you want to boot in recovery or boot the system with Magisk installed.
1. Powering up normally → System with no Magisk
2. Power + Volume Up → Bootloader warning → Release all buttons →System with Magisk
3. Power + Volume Up → Bootloader warning → Keep holding volume up → Actual recovery