Has anyone managed to downgrade a 2015/foster unit to 7.1? I can't do it on mine. The bootloader version displayed on the TV does not change, and boot images that worked before 7.2 just hang on the Nvidia logo.
That is no good news Mogster 
I was hoping the older models would not get the new bootloader.
I am not 100% sure whether it is the 7.2 already or the later bootloader, but they won't allow a downgrade anymore.
Almost certain I still could under 7.2.
As we can't sign them we can't use a modifed old one one to spoof a new version number.
And I doubt the system would boot if we could.
Too much on the partitions we can no access has changed.
I am working ona firmware that again gives us full and open access but first I need a working TWRP again
In theory all should work just fine but I can not flash it to test it as simply flashing system-, boot-, and vendor partitions won't do it.
Ayn attempt with a 7.2.x bootloader to use a custom recovery marks the system as corrupt.
Right not I am not sure if that is still true after a full wipe and format through TWRP.
So far I tend to say no and the install of a fresh firmware fixes it.
Running around in a very annoying cricle with this problem....
If anyone one is able to go back to some firmware or TWRP version that again gives us full write access and working flashing and restores then speak up please!
Getting TWRP "working" with the Zulu99 DTB is one thing, writing a backup back that actually boots and successfully flashing a zip is another story.
Hopefully someone has more time than I have to search through the to be released 7.2 sources to provide something that fully works.
In the meantime I reject reality and substitute my own!
There is a way, I just need to find it LOL
I was hoping the older models would not get the new bootloader.
I am not 100% sure whether it is the 7.2 already or the later bootloader, but they won't allow a downgrade anymore.
Almost certain I still could under 7.2.
As we can't sign them we can't use a modifed old one one to spoof a new version number.
And I doubt the system would boot if we could.
Too much on the partitions we can no access has changed.
I am working ona firmware that again gives us full and open access but first I need a working TWRP again
In theory all should work just fine but I can not flash it to test it as simply flashing system-, boot-, and vendor partitions won't do it.
Ayn attempt with a 7.2.x bootloader to use a custom recovery marks the system as corrupt.
Right not I am not sure if that is still true after a full wipe and format through TWRP.
So far I tend to say no and the install of a fresh firmware fixes it.
Running around in a very annoying cricle with this problem....
If anyone one is able to go back to some firmware or TWRP version that again gives us full write access and working flashing and restores then speak up please!
Getting TWRP "working" with the Zulu99 DTB is one thing, writing a backup back that actually boots and successfully flashing a zip is another story.
Hopefully someone has more time than I have to search through the to be released 7.2 sources to provide something that fully works.
In the meantime I reject reality and substitute my own!
There is a way, I just need to find it LOL
I do have a rooted shield with 7.1 and TWRP working. Removed the Shield OTA, because I was aware some stuff like this might happen.
If we are not able to bring back Magisk, this Root approach might help us keeping the Shield rooted: https://forum.xda-developers.com/android/software/root-backdoor-android-kernel-development-t3870559
Or a custom kernel with a modified fstab bringing back the system Partition maybe?
If we are not able to bring back Magisk, this Root approach might help us keeping the Shield rooted: https://forum.xda-developers.com/android/software/root-backdoor-android-kernel-development-t3870559
Or a custom kernel with a modified fstab bringing back the system Partition maybe?
@ Adromir: I will check the link and options that it might offer but first I have a huge requst:
I suspect that my ongoing experiments have caused some serious issues on my shield.
If yours is a 2017 model then I would appreciate a full TWRP backup of the entire system.
From a freshly installed 7.1 I then might be able to get all bootloader things back to normal, at least I hope so
I might have found a possible backdoor.
Under certain conditions I noticed that I have a working ADB root connection around the time the NVidia logo shows up.
It is only for a few seconds if it happens but with a bit of luck this time could be used to start a shell script to modify the system partition.
Things like renaming the OTA folder, pushing a modified build.prop...
I suspect that my ongoing experiments have caused some serious issues on my shield.
If yours is a 2017 model then I would appreciate a full TWRP backup of the entire system.
From a freshly installed 7.1 I then might be able to get all bootloader things back to normal, at least I hope so
I might have found a possible backdoor.
Under certain conditions I noticed that I have a working ADB root connection around the time the NVidia logo shows up.
It is only for a few seconds if it happens but with a bit of luck this time could be used to start a shell script to modify the system partition.
Things like renaming the OTA folder, pushing a modified build.prop...
Hey Downunder, I could go back to 7.1 for you and get a full backup if you want me to. Just let me know.@ Adromir: I will check the link and options that it might offer but first I have a huge requst:
I suspect that my ongoing experiments have caused some serious issues on my shield.
If yours is a 2017 model then I would appreciate a full TWRP backup of the entire system.
From a freshly installed 7.1 I then might be able to get all bootloader things back to normal, at least I hope so
I might have found a possible backdoor.
Under certain conditions I noticed that I have a working ADB root connection around the time the NVidia logo shows up.
It is only for a few seconds if it happens but with a bit of luck this time could be used to start a shell script to modify the system partition.
Things like renaming the OTA folder, pushing a modified build.prop...
Let me try first to manually go from 7.2.1 to 7.2 and then 7.1.
Can't be impossible to get the thing back to what is was LOL
Will let you know in a few hours, thanks!
Can't be impossible to get the thing back to what is was LOL
Will let you know in a few hours, thanks!
Ok, I am back in business with a fully working Shield on 7.1
-Only problem left is that I can not push files through ADB onto the internal storage anymore.
ADB states the directory does not exist, but pulling files from the exact same directories works fine LOL
As I now could finally use my old backup again, I updated to the latest Kantjer Magisk and still all worked fine.
Now, to stay "clean" I will see what happens if I try to flash a modifed firmware with just the OTA APK renamed over the existing 7.1.
If that already fails then at least I have a problem.
-Only problem left is that I can not push files through ADB onto the internal storage anymore.
ADB states the directory does not exist, but pulling files from the exact same directories works fine LOL
As I now could finally use my old backup again, I updated to the latest Kantjer Magisk and still all worked fine.
Now, to stay "clean" I will see what happens if I try to flash a modifed firmware with just the OTA APK renamed over the existing 7.1.
If that already fails then at least I have a problem.
Hey mate, I made a debloated, pre-rooted 7.1 firmware with firmware updates turned off if you want to try. Flashed trough twrp for me with no issues. Just let me know.
LOL - That is what I did too.
But it seems I have EPA problems, my enviroment must be pulluted.
Getting to close to giving up and installing Winodws from scratch here.
Guess at some point some install included with the NVidia developer suite messed things up big time.
With the Shield working fine now again I jumped back to manual labour on the shield and I can mod the living crap out of it.
But even my oldest kitchen tools now totally fail to create something as simple as a flashable boot.img.
So I added breaks here and there, more info output and I came to this conclusion:
All my Python, VB and Java stuff claims to work fine but when running decent tests then none of them actually execute from the right place or in the correct way.
For example simply PY scripts including memory operations go nuts and give results that make no sense.
Nvidia was nice enough to provide an installer for ALL their crap that simply overwrites and changes whatever it feels like in the system.
But there is no option to uninstall any of it, just to update.
With an amount of install that feels like endless it will hard to get around a fresh Windows
So in a last ditch attempt I signed up for your kitchen and in there I am bomabrded with python related errors all over the place, can't even update it.
Of course I uninstalled and installed all related things now several times but the outcome stays the same.
That's what happens if you think building roms from source is good thing ROFL
If there is one thing this entire fiasco has shown then not to trust NVidia.
Linus was sooo right with his comments LOL
But it seems I have EPA problems, my enviroment must be pulluted.
Getting to close to giving up and installing Winodws from scratch here.
Guess at some point some install included with the NVidia developer suite messed things up big time.
With the Shield working fine now again I jumped back to manual labour on the shield and I can mod the living crap out of it.
But even my oldest kitchen tools now totally fail to create something as simple as a flashable boot.img.
So I added breaks here and there, more info output and I came to this conclusion:
All my Python, VB and Java stuff claims to work fine but when running decent tests then none of them actually execute from the right place or in the correct way.
For example simply PY scripts including memory operations go nuts and give results that make no sense.
Nvidia was nice enough to provide an installer for ALL their crap that simply overwrites and changes whatever it feels like in the system.
But there is no option to uninstall any of it, just to update.
With an amount of install that feels like endless it will hard to get around a fresh Windows
So in a last ditch attempt I signed up for your kitchen and in there I am bomabrded with python related errors all over the place, can't even update it.
Of course I uninstalled and installed all related things now several times but the outcome stays the same.
That's what happens if you think building roms from source is good thing ROFL
If there is one thing this entire fiasco has shown then not to trust NVidia.
Linus was sooo right with his comments LOL
I'd like to try that.
How many apps are debloated anyway? Will this pre-rooted with Magisk? I'm on 7.1 with SU root (Shield 2017 16gb) but want to try Magisk.
Thanks in advance.
Probably too many for most people, but I deleted Amazon Video, Google Games, Music, Video etc, Youtube, all the BBC crap. a few language and Keyboard packs I don't need. Nothing that can't be reinstalled if needed. It is pre-rooted with the normal version of Magisk 18. Just need to open Magisk Manager to finish the setup. Best thing about it for most users if they are happy with 7.1, you won't get prompted to update. Me personally, I will be going back to the 7.2.2 Engineering Firmware, but made a Custom 7.1 Firmware for the 2017 Darcy model just to see if it would work really. Now that I see that it does, I will most likely go back to 7.2.2 and see what I can do there.
But if you are interested in trying the Custom 7.1, here is a link: https://mega.nz/#!ShNXGY7I!_BD9zUl-yudtSV-V_IOWa3FpA6Sr2tykCfM71K0-XpQ
Just make sure you take a backup of your setup first, just in case things don't work out or you don't like it then you can flash back your setup.
Only little issue I noticed, once I flashed through twrp, I let it boot up and then I did a Factory Reset as this is the process I like to do when trying/testing new setups etc, on first bootup, when it was doing the Playstore updates, the screen went black, can't remember 100% if it rebooted itself or if I left it for 5-10 mins and then done a Power Reboot myself, but after Reboot everything was fine. Let me know how it goes.
If you could leave feedback on whether it flashed for you or not and how it worked for you, that would be great.
@whiteak
Just install your debloated rom, all went well.
At first boot after wifi connected successfully my shield went black screen for 3-5 minutes and then appears welcome screen.
Thanks for the file. I will playing around a bit more to see if there's any issues.
Update
- magisk app seems fail to update and open on first start. I just uninstall and reinstall magisk manager 6.1 and let it updates itself which all went well this time.
- I noticed that pre-installed magisk is 18.1rc unofficial I wonder when there is an official version of magisk 18.1 or newer can I update to the official version or should I leave it as is?
Just install your debloated rom, all went well.
At first boot after wifi connected successfully my shield went black screen for 3-5 minutes and then appears welcome screen.
Thanks for the file. I will playing around a bit more to see if there's any issues.
Update
- magisk app seems fail to update and open on first start. I just uninstall and reinstall magisk manager 6.1 and let it updates itself which all went well this time.
- I noticed that pre-installed magisk is 18.1rc unofficial I wonder when there is an official version of magisk 18.1 or newer can I update to the official version or should I leave it as is?
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You must have installed a unofficial Magisk Manager and not the Official one as the version of Magisk should be Official 18.0. I actually like to use Kantjers version, but the kitchen I used when making the Rom used the official 18.0, as it was mainly a test, I just left it at that. If you wanted to, you could run the Magisk uninstaller and then flash whatever version you wanted, totally up to you.
Thanka for advice.
I thought the magisk version 18.1r5-unofficial comes with your rom.
Anyway I just press install v18.0 in magisk manager and choose direct install. The process goes successfully. Now I'm on magisk official 18.0.
Hellow may i have download link of your TWRP.img which you used to flash Whiteak custom rom. I want to flash it to my 2017 shield tv running 7.1. When you flash the rom, you flash twrp to your shield first or you can temp boot to twrp to flash the rom, thank you.
I didn't try the 7.1 Rom with a 7.2 bootloader, but I did try a custom 7.2.2 rom with the 7.2 bootloader, it flashes a white screen and goes on a boot loop, I'm sure if I flashed zulu99's dtb file it would probably boot, but I have 2 shields, one I am running the 7.2.2 Engineering test images and the other I am running the 7.1 with firmware updates disabled etc.
Just trying to verify, some say you dont need DTB file to get full root access on Pro(foster) others say you do. Which one is it?
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