[GUIDE] Install GSI on U.S. Snapdragon S9/S9+ [U/U1 Variants]

[ShaDisNX255]

So...

The U.S. variants finally have root, this is a very exciting moment for S9/N9/S9+/N9+ users that always wanted to do more with your device. I wanted to create this thread separate from the root thread as I think GSIs are a whole different thing. It's actually pretty simple once you've read, understood and even tried the root method running Oreo Samsung Experience. The steps are very similar but you just swap out the system image.

So please, take the time to read the thread for the Extreme Syndicate root method here: https://xdaforums.com/galaxy-s9/sam...pment/root-t4041815/post81608559#post81608559
I am going to quote some of the stuff in that thread directly as all of it still applies here.
Please take your time and make sure you follow the instructions carefully.

This method is brought to you entirely by @elliwigy He is the reason for this exploit and method.
With that being said, Extreme Syndicate Root is now available!

​

Disclaimer:

The Extreme Syndicate team and it's affiliates are not responsible for your actions or your device if any issues are to arise. You flash this and utilize these files at your own risk. You have been warned!


The Adventure!:

I will not get into any technical details here. Just know that this method has taken me ~1 year from start to finish. I also went through a number of devices during this time (at least 7 devices), even sold my original N9 then somehow ended up with another one before this root method was found. Some of us devs might be a bit burnt out so don't get upset if we are not in here all day every day answering everyones questions. We hope users will help eachother, that is what XDA is all about! Also, if you want more real time conversation/support then please join our Telegram group (link posted below) as this is easier for us to moderate and allows discussion to be had in real time. I don't always check XDA messages or PM's as it can be a lot and very tiresome so your best bet is Telegram!

Also, donations/money is not expected or required but if you feel obliged to share what you can then that would be greatly appreciated! Donations keep me on the grind and sometimes can even help me in acquiring other devices to work on. I had issues with Paypal a while back (SamPWND days) and do not have a Paypal account. I do however have a Venmo and Transferwise accounts that work in most situations.

Venmo - http://www.venmo.com/Thomas-Huntington-10

Transferwise - PM @elliwigy for info to donate using Transferwise.


Now Let's get into the files/method!

INSTRUCTIONS:

1. Download the following:
- Root files from Extreme Syndicate that belong to your device
- The GSI you want to download (for these devices you need arm64 a-only. With gapps included should be your priority)
- Sh remover zip uploaded here.
- Alternative: ODM nosu zip

2. In odin folder flash the combo firmware

3. Once combo is booted up run the root bat. When done phone will reboot to download.

4. In odin flash the bootswap.tar.md5 file. What this does is swaps the boot and recovery images which allows system to be mounted rw.

5. Now when done flashing you need to hold the buttons to boot to recovery but since we swapped boot and recovery images it will boot system.

6. Now put your phone in airplane mode. This must be done whenever using Flashfire. Copy the system.img (your GSI img) , vendor.img, Sh remover.zip and ODM zip files to your phone.
- NOTE: Flashfire doesn't let you chose the partition on where it's going to flash any image. It decides on where to flash based on the name of the image. So if your gsi is named GSIName-arm64-a-nosu.img then flashfire will have no idea where to flash it. I would rename the img to something like system-GSIName-arm64-a-nosu.img.... or just system.img lol
- NOTE 2: I uploaded a ODM NOROOT.zip. Reason being that some gsi come preloaded with supersu. In theory, using the regular ODM_ROOT.zip from the Extreme Syndicate method should work fine even if the GSI comes prerooted, I just didn't test it with that lol. You should definitely use the root variant if the GSI doesn't say it comes rooted.

7. In Flashfire, choose zip and select the odm zip (root or unrooted, your choice. Read note above). Make sure you select "Mount /system read/write" when the Options pop up. This is necessary or else it will not boot, always chose this on everything. Then choose firmware and choose the system.img and the vendor.img. Then choose data wipe and wipe user and system data (the default choices). Make sure inject super su is NOT enabled. Disable it. Do not let flashfire inject root!!. Then choose zip again and select the Sh remover.zip (select to mount system read/write)
- NOTE: I added the Sh remover zip because some GSI (particularly Android 9 GSI) have a track record of having some problems booting up in Samsung devices. This zip should remove the system/bin/rw_system.sh file. There's no bad side of not having this file on GSI's that don't share this problem, so I'm making it a mandatory step to avoid as much problems as possible

8.. Now click flash. When finished you will have to hold buttons to reboot to recovery until you see boot animation. You must do this on every reboot. If you do not it will reboot to stock recovery. If it reboots to stock recovery just reboot system and hold buttons to reboot to recovery again.

9. When rom is booted up your computer will not recognize the phone for mtp file transfer. Adb does still work so you can transfer stuff that way (you need to switch to ptp transfer method in the dropdown) or use USB adapter and use a thumb drive.

10. Biometrics do not work so don’t try to setup fingerprint or face recognition.




And that's it, you should have your GSI up and running.
Let's keep all the GSI talk on this thread please. I will do my best to keep this thread updated with fixes, compatibility and news. For now, take a look at the confirmed working GSI:



Confirmed working:
- PHH Android 9 GSI
- HavocOS 2.9
- PHH Android 10 GSI (Added bug: WiFi is broken, working on a fix)


Confirmed not working:
- Pixel Experience Android 9
- OxygenOS (Erfan's GSI) (I wouldn't recommend GSI from other OEMs anyway)




ShoutOuts:

@elliwigy For the method and help and everything else
@klabit87 - Ditto
@me2151 - Ditto
@gsm-CHEN - Ditto
@jrkruse - For all the help and support for S9 variants
@everyone else I am forgetting!


ENJOY!

 

[ShaDisNX255]

Join is in Telegram where we can discuss GSI and help with problems more quickly

Link: https://t.me/joinchat/HYvgAlUgyqKq9__Y5yg1uA

 

[ShaDisNX255]

Reserved 2

 

[klabit87]

Nice guide! I'm sure you'll have plenty of input from others that have tested various gsi.

 

[ShaDisNX255]

Nice guide! I'm sure you'll have plenty of input from others that have tested various gsi.

That's the plan. To hopefully fill this thread with GSIs that work, the ones that don't and any additional fixes to get some to boot.

 

[ShaDisNX255]

Great news. Seems HavocOS 2.9 (Android 9) boots pretty well. This is great! Udating post to add link.


EDIT: Also added PHH Android 10. It boots!

 

[svaethier]

just so everyone knows, so far the bugs with the PHH 9 GSI is that no mobile data,messaging and calling will work.

 

[Zaileion]

Root on "U" variants! Wahooooo!! Ooo! Ooo!

Anyway, I've been doing this since the galaxy s3 and jailbreaking iPhone since the 3gs... but it's not a every day thing for me and I would assume the same for many others. I do it full tilt "all of my personal time" for a few months get stuff working, backup and then go about my business. I have been forced to switch from my beloved note 4 to this corporate controlled piece or Samsung stuff for $1K and finally someone hacked it! Well done and thank you soooooo very much!!

Anyway, this GSI thing is entirely new to me. I dont know what it is, how it works, what is means etc... it seems to be a relatively new thing. Maybe within the past year or so?

So what I would recomend and ask for is a brief history and explanation of what it is and what is does, where it came from etc... does it make my touchwiz phone like stock android? What aspect of the rom does it replace? System.img I assume but why is it needed? What is the reason it's not needed for Android 8 but is needed for 9 and up?

Of course all of us can google it and and wade through all the documentation on it which I will do and eventually figure it out but I noticed on telegram there are a ton of questions about it since, well, almost everyone has Android 9 on their devices. So it might help in reducing the repetitive questions if there was a quick but detailed write up on GSI from some of you ultra smart type peeps that know about it. My guess is most people won't spend the necessary time required to research GSI which can take days, weeks, months... some of us have kids and demanding jobs and have to cook, clean, repair, work, doctors, school, etc etc.. while others such as myself have opted to go the route of a professional career with no kids and can spend the time researching... Just a suggestion...

Again thank you to all the super smart type fellas and ladies aka DEVs that continue to fight the good fight and make this entire thing possible for the rest of us that are less capable in this area of expertise . You guys rock! Like kick serious @$$ kinda rock!

 

[ShaDisNX255]

Root on "U" variants! Wahooooo!! Ooo! Ooo!

Anyway, I've been doing this since the galaxy s3 and jailbreaking iPhone since the 3gs... but it's not a every day thing for me and I would assume the same for many others. I do it full tilt "all of my personal time" for a few months get stuff working, backup and then go about my business. I have been forced to switch from my beloved note 4 to this corporate controlled piece or Samsung stuff for $1K and finally someone hacked it! Well done and thank you soooooo very much!!

Anyway, this GSI thing is entirely new to me. I dont know what it is, how it works, what is means etc... it seems to be a relatively new thing. Maybe within the past year or so?

So what I would recomend and ask for is a brief history and explanation of what it is and what is does, where it came from etc... does it make my touchwiz phone like stock android? What aspect of the rom does it replace? System.img I assume but why is it needed? What is the reason it's not needed for Android 8 but is needed for 9 and up?

Of course all of us can google it and and wade through all the documentation on it which I will do and eventually figure it out but I noticed on telegram there are a ton of questions about it since, well, almost everyone has Android 9 on their devices. So it might help in reducing the repetitive questions if there was a quick but detailed write up on GSI from some of you ultra smart type peeps that know about it. My guess is most people won't spend the necessary time required to research GSI which can take days, weeks, months... some of us have kids and demanding jobs and have to cook, clean, repair, work, doctors, school, etc etc.. while others such as myself have opted to go the route of a professional career with no kids and can spend the time researching... Just a suggestion...

Again thank you to all the super smart type fellas and ladies aka DEVs that continue to fight the good fight and make this entire thing possible for the rest of us that are less capable in this area of expertise . You guys rock! Like kick serious @$$ kinda rock!

I can sort of give a very brief explanation of sort of how I see it.
And I say sort of because I really don't consider myself an expert, just read a few things here and there
I'm going to go over what "Project Treble" really is, I don't know if you've heard this term thrown around when talking about GSI.
Google made "Project Treble" much more simple with the intention that OEMs would hurry up and release updates faster lol
What happens now is that there is a new partition of where the Android OS takes its resources, and that's the "/vendor" partition. Everything from the drivers to the bluetooth, wifi, sensors, camera, etc.... is found here
Every device that are "Treble" enabled means that they have this "/vendor" partition
So why the S9? Why not the S8, S7, etc...?
Google made it mandatory for all the devices that released with Android Oreo to be "Treble Enabled" out of the box and made it up to the manufacturer to make old devices Treble compatible
But let's not kid ourselves, we all knew that Samsung wouldn't go back on the S8, S7, Note 8, etc... and treblelize them, that's not their style. Though most OEM's didn't do that anyway, there are a very few that actually did.
From the S9 and onwards, all these devices have Project Treble.
So, now we get to what the GSI actually are.
Think of it as ROMs, pretty straight forward.
Now the AndroidOS takes all its hardware resources from "/vendor", these GSI can work on almost all devices out there. Sure there may still exists some compatibility issues here and there but it's much easier to fix them.
So in theory, even if Samsung stops development on the S9 with Android 11, which of course we're all expecting, we can still flash Android 11 GSI when they start coming out because the S9 is Treble enabled
I hope this sort of gave you an idea of what the whole GSI and Project Treble situation is.

 

[meetr1912]

PHH Android 9 GSI - Calls no Volume Fix

Just to add onto that, I would like to say that If you are to flash PHH Android 9 GSI and HavocOS 2.9. It doesn't have the calling feature working from the get go. You would be able to make a call to a person, but you won't be able to hear them or they won't be able to hear you. This is an ongoing problem with that GSI. A possible work around for that would be found on

https://xdaforums.com/asus-zenfone-max-pro-m1/how-to/guide-call-fix-patch-gsi-testing-t3791660

Although, I haven't tried it. I am in the process to try and fix this. Will update once done. I cannot thank enough the author and everyone else involved in getting this root to work and along with that being able to flash custom Roms. This is amazing.

 

[Mogster2K]

What about AOSP 9.0 and 10.0? Do those work?

 

[ShaDisNX255]

What about AOSP 9.0 and 10.0? Do those work?

I personally haven't tested any more, been busy. You are free to test them yourself and post links to which work. The one consistent bug we did find on Android 10 GSI is broken WiFi.

 

[bigrat]

This works on the 965U, the locked ATT version? This does work on the 965U, I answered my own question.

EDIT: this does not trip knox, sorry for the question. I am RTFM now

 

[Mogster2K]

Which vendor.img should we use if flashing PHH's GSI 9 or 10?

 

[ShaDisNX255]

Which vendor.img should we use if flashing PHH's GSI 9 or 10?

The latest Oreo one included in the Syndicate root method

 

[Mogster2K]

I've run into a problem. I thought PHH's GSI did not have root installed but apparently it does. Unfortunately I flashed ODM_ROOT.zip instead of ODM+NOROOT.zip, and it seems to have broken FlashFire. It's stuck on "Acquiring root access" even tho it already has root. Is there a way to fix this without losing root, or is there another app I can use besides FlashFire? Thanks

 

[ShaDisNX255]

I've run into a problem. I thought PHH's GSI did not have root installed but apparently it does. Unfortunately I flashed ODM_ROOT.zip instead of ODM+NOROOT.zip, and it seems to have broken FlashFire. It's stuck on "Acquiring root access" even tho it already has root. Is there a way to fix this without losing root, or is there another app I can use besides FlashFire? Thanks

Huh... so now we know that a rooted GSI + the ODM_ROOT zip DOES cause a problem.
Yeah it sucks that on some GSI, the devs don't disclose it's got SU binaries already
What I would do is to look inside one (or both) of your SU apps and see if Flashfire has requested for SU access and it's got it negated for some reason.
If not, then I would just start over with the whole rooting process

 

[TheMadScientist]

I've run into a problem. I thought PHH's GSI did not have root installed but apparently it does. Unfortunately I flashed ODM_ROOT.zip instead of ODM+NOROOT.zip, and it seems to have broken FlashFire. It's stuck on "Acquiring root access" even tho it already has root. Is there a way to fix this without losing root, or is there another app I can use besides FlashFire? Thanks

Also clear the data for flashfire and force close it. I. The past we had to just grant all su permissions to get it to work flashfire has been real buggy on s8 and up sometimes
Safe strap possibly.

 

[Mogster2K]

Huh... so now we know that a rooted GSI + the ODM_ROOT zip DOES cause a problem.
Yeah it sucks that on some GSI, the devs don't disclose it's got SU binaries already
What I would do is to look inside one (or both) of your SU apps and see if Flashfire has requested for SU access and it's got it negated for some reason.
If not, then I would just start over with the whole rooting process

Yeah, that's what I ended up doing. I managed to get the rooted Oreo image installed. Another note: PHH 10 v213 does not work with Spectrum Wireless (code CHA). I had no wifi and no mobile data and was stuck on the Google setup for a long time. Anyone here have Spectrum working on a GSI?

 

[Mogster2K]

Just confirmed that Spectrum Wireless data doesn't work on PHH 9.0 v123 either.