Samsung Galaxy S9 and Samsung Galaxy S9+ both shipped with Android 8.0, which means Project Treble support out of the box. This feature has a lot of potential and it’s even more exciting when you can unlock the bootloader on the device. After unlocking, you can flash your favorite recovery, such as TWRP, and start flashing anything you see available for your device. Some models of the Galaxy S9 can have their bootloader unlocked. We have good news for those users.
Thanks to XDA Senior Member travis82, an unofficial version of TWRP is now available for Snapdragon versions of both the Galaxy S9 and Galaxy S9+. Unfortunately, that means that US models can’t have the custom recovery since their bootloaders can’t be unlocked. However, users in Hong Kong and several Latin American countries also have the Snapdragon variants.
Keep in mind that this will trip Knox to 0x1 and void your phone’s warranty. But, if you’re reading this post about custom recoveries, you probably already knew about that and don’t care. The only notable bug to write about is that Samsung encryption is not supported.
You can download an unofficial releases from the links below for Galaxy S9 and S9+.