In this tutorial, I will show you how to install Android 10 or 11 GSI ROMs on Galaxy S9 or S9 Plus. This method is ONLY for Galaxy S9 or S9 Plus, please do not try on other Samsung phones(although it may work on some.
This will work on any Exynos Galaxy S9 or S9 Plus. If you have U.S. model, it will not work as you cannot unlock the bootloader, sorry!
NOTE: WE WILL ERASE EVERYTHING ON YOUR PHONE AS THAT IS REQUIRED TO INSTALL GSI SO PLEASE MAKE BACKUP BEFORE TRYING THIS AND ALSO WATCH THE VIDEO TUTORIAL BEFOREHAND!!!
Before beginning this tutorial, download the latest Android 10 firmware for your Galaxy S9 or S9 Plus just in case things go wrong. (You can download firmware here: https://samfw.com/)
Step 1. You will need to unlock the bootloader, make sure “OEM Unlock” is checked ON in Developer Settings. That should be enough but if you are on newer firmware, you might have to reboot into Download mode and actually unlock the bootloader.
Step 2. Download all the file you will need.
Download Samsung USB Drivers:
Download TWRP for Exynos Galaxy S9:
Download TWRP for Exynos Galaxy S9 Plus:
You will need to flash THIS PARTICULAR version of CRDroid ROM as base for GSI ROMs. I accidentally came upon this idea after trying to get GSI working for 5 days straight.
Download CRDroid ROM for Galaxy S9:
Dowload CRDroid ROM for Galaxy S9 Plus:
Download DM Verify:
Download Permissiver V5:
Download any Android 10/11 GSI ROM of your choice!
For Android 11, I recommend latest AOSP Android 11.0 by Husson here:
For Android 11, make sure to grab Android 11 Gapps here also:
For all other GSI, look here on XDA: (You can grab one with Gapps so you don’t have to install Gapps separately)
You will need to download ARM64 “AB” version of the GSI!
Make sure to extract the .img file from .img.xz or .zip file using 7zip.
Step 3. Make sure you are on Android 10 stock firmware.
Step 4. Reboot into Download mode.
Step 5. Flash TWRP recovery using ODIN but MAKE SURE to REBOOT INTO RECOVERY USING THE BUTTONS right away without letting the phone reboot otherwise YOU WILL HAVE TO REFLASH STOCK FIRMWARE! Watch my video tutorial before attempting so you don’t end up with a bootloop!!! If you miss this step, you can follow this guide here to reinstall stock firmware and try again: https://highonandroid.com/android-smartphones/how-to-unroot-galaxy-s9-s9-plus-w-stock-firmware/
Step 6. Once rebooted into TWRP, wipe data and reboot TWRP.
Step 7. Wipe cache, dalvik cache, system, and data.
Step 8. Install the CrDroid ROM then reboot.
Step 9. Once rebooted into ROM, reboot back into TWRP.
Step 10. Wipe cache, dalvik cache, system, and data again.
Step 11. Install the CrDroid ROM.
Step 12. Install GSI image.
Step 13. Install DM No Verify and Permissive_V5 zip files.
Step 14. Reboot. You will probably get stuck on bootloop. Reboot to TWRP by resetting, hold down Volume Down and Power buttons until it resets then immediately hold down Volume Up, Bixby, and Power buttons to reboot to TWRP.
Step 15. Wipe cache, dalvik cache, system, and data again.
Step 16. Install GSI image.
Step 17. Reboot and profit! Enjoy!
If you want to change ROMs, simply reboot into TWRP and you just need to repeat steps 15 thru 17. Once you have setup the phone, you can install other GSI easily and quickly, just first time it takes forever.
*Note - I found this method by accident and took me many days to repeat it. If you miss any of the steps you will end up in a bootloop. For explanation of what is going on, please watch my video tutorial.
If you want to root, after booting, you can reboot back into TWRP and install Magisk beta zip here:
NOTE: Phusson’s Android 11.0 GSI is NOT COMPATIBLE with Magisk root! I am working on a new GSI that will be so check back!