For those of you who have installed a GSI ROM on your Samsung Galaxy S10 series, S20 series, Note 10 series, Note 20 series, or the A10/A20/A30/A40/A50/A51/A60/A70 series using my guide here(How to Install Android 10/11 GSI on Galaxy S10/S20/Note 10/Note 20/A Series!), here’s how to root it easily using Magisk and by patching your TWRP recovery image.
Now, because Samsung has changed things up starting with Galaxy S10 and up, you no longer have a ramdisk so in order to get Magisk root, we must patch TWRP recovery in order for the system to boot into TWRP then into system. You will also have to use button combo every time you boot to enable Magisk root.
Follow along w/ the video tutorial here:
Step 1. Extract the recovery.img from the TWRP tar file that you used when installing the GSI ROM.
Step 2. Install Magisk Canary APK and use it to patch the recovery.img.
Download Magisk Canary APK:
Step 3. Reboot into TWRP and flash the patched recovery image into the Recovery partition.
Step 4. To boot with Magisk root, power off your phone then hold down Volume Up, Bixby, and Power buttons together and LET GO OF ALL BUTTONS when you see the boot up logo. YOU MUST DO THIS EVERYTIME YOU BOOT in order to get Magisk root otherwise it will boot normally without boot.
Step 5. Once booted, your Magisk Manager app should say it has been installed. Congratulations! Enjoy your rooted GSI on your Samsung smartphone!
SafeNet Check not passing? Here’s how to make it pass: