SM-T295 - Finally rooted tablet!! (updated 19-March-2021)

[ebod]

Look at this 2 threads:
1. https://forum.xda-developers.com/t/get-param-bin-file-samsung.3782066/ (FIRST)
2. https://forum.xda-developers.com/t/guide-how-to-find-param-partition-block-samsung.3906650/ (Look at this one when told in first one)
You can try to extract the param file using this method. These commands can be run from the terminal in TWRP.

I understand getting a pc command prompt but not 100% sure what 'state' the device must be in when connected to the PC. i.e. must it be in download mode or TWRP ? or just standard active running mode? Do you just suggest abandoning the pc access and try via TWRP alone ?

 

[J.Michael]

As part of getting root, I had to add another 'BL' file per the tutorial. So there is a stock BL file and one associated with the root tutorial. But in any case I've looked at both with the 7zip you linked and neither shows an "up_param" file

I think you are wasting your time trying to eliminate the nag screen before you address the real issue.

Getting the tablet to automatically boot when power is applied is going to involve manipulating the filesystem. I don't think you're going to be able to just remount /system and edit something. That thread @Minionguyjpro found talks about unpacking the boot image and modifying it's ramdisk and repacking the boot image. That's a lot of steps where something can go wrong.

If you decide to live with having to push a button to boot the tablet, you will probably find that waiting for the nag screen to time-out is not such a big deal.

And it probably takes a lot of work to make the tablet shut down when you turn off the car. So, unless you go a long time without using the car, the tablet is already booted. At worst, you need to get past the lock screen. I haven't seen anyone talk about that. Maybe you just disable it in Android Settings.

 

[Minionguyjpro]

I think you are wasting your time trying to eliminate the nag screen before you address the real issue.

Getting the tablet to automatically boot when power is applied is going to involve manipulating the filesystem. I don't think you're going to be able to just remount /system and edit something. That thread @Minionguyjpro found talks about unpacking the boot image and modifying it's ramdisk and repacking the boot image. That's a lot of steps where something can go wrong.

If you decide to live with having to push a button to boot the tablet, you will probably find that waiting for the nag screen to time-out is not such a big deal.

And it probably takes a lot of work to make the tablet shut down when you turn off the car. So, unless you go a long time without using the car, the tablet is already booted. At worst, you need to get past the lock screen. I haven't seen anyone talk about that. Maybe you just disable it in Android Settings.

And that, and it goes automatically further, even though no one presses it.

 

[Minionguyjpro]

I understand getting a pc command prompt but not 100% sure what 'state' the device must be in when connected to the PC. i.e. must it be in download mode or TWRP ? or just standard active running mode? Do you just suggest abandoning the pc access and try via TWRP alone ?

It can be either in TWRP or in the normal mode, as long as ADB/USB debugging is enabled, I think.

 

[ebod]

It can be either in TWRP or in the normal mode, as long as ADB/USB debugging is enabled, I think.

tried both and no success either way, I selected a Samsung as a car based tablet because I genuinely thought it would be the most supported device brand to configure. Seriously concluding why do I bother as nothing is straighforward. It would less stress just listening to crackly FM radio as can't see me getting this device to behave like a car head unit. I've successfully got a stock LG G5 phone running as a car based unit that switches on/off etc without my input. Only problem with that is its too small screen'wise

Like they have Apple stores in all major cities, kinda wish I could take in this tablet to a Samsung store and get an in-store expert make it car friendly :-/

 

[tamtc84]

You can roll back to android 9, but with version 3 of the loader, say T290XXS3ATF1 . Alternatively, on the current full firmware of android 11, just look at how charging works when the device is turned off.Then flash the bootloader from android 9 aboot_vbmeta_T290XXS3ATF1.tar and compare the picture when charging. You don't need to root, just see the root of the problem...
I never turn off the device, so I don't see a problem when charging...

I upgrade A8 T295 from T295XXS3ATB2_T295OLM3ATB2_XEV_9.0 to T295XXS5CWA1 by Odin. Success to upgrade.
When i want to rollback to T295XXS3ATB2, i received message: "sw rev check fail fused 5 binary 3".

How do I do to rollback to T295XXS3ATB2? or setup T295XXS3ATB2 again to root with Magisk?

Many thank.

 

[J.Michael]

I upgrade A8 T295 from T295XXS3ATB2_T295OLM3ATB2_XEV_9.0 to T295XXS5CWA1 by Odin. Success to upgrade.
When i want to rollback to T295XXS3ATB2, i received message: "sw rev check fail fused 5 binary 3".

How do I do to rollback to T295XXS3ATB2? or setup T295XXS3ATB2 again to root with Magisk?

Many thank.

You don't. Not without more control than anyone we know has. They don't want you to be able to roll back. They seem to have done a good enough job, you cannot roll back.

 

[tamtc84]

You don't. Not without more control than anyone we know has. They don't want you to be able to roll back. They seem to have done a good enough job, you cannot roll back.

Can i use another combination firmware to reset fused. After that flash again with T292XXS3ATB2?

 

[J.Michael]

Can i use another combination firmware to reset fused. After that flash again with T292XXS3ATB2?

Still no. Just throwing their software against their gatekeeper is not going to bypass their "protection".

Where did you get "sw rev check fail"?

If in download mode, when you used Odin, and you could then boot to Android, then they didn't even let you write the unapproved software. You would need some secret super-Odin, or you would need to open the box and place probes in the right place to rewrite PROM, to force your choice of software back onto the device.

If you get the failure when trying to boot Android, and you have to use Odin to restore the approved bootloader, and you are able to use Odin to restore the approved bootloader, and then you can boot, then there is a software solution. But you would probably have to crack their signing protocol to create a bootloader that claims to be the right revision, and yet allows you to do what you want. I think you could solve the challenge of burning a PROM more easily than you could crack Samsung's encryption.

 

[tamtc84]

Still no. Just throwing their software against their gatekeeper is not going to bypass their "protection".

Where did you get "sw rev check fail"?

If in download mode, when you used Odin, and you could then boot to Android, then they didn't even let you write the unapproved software. You would need some secret super-Odin, or you would need to open the box and place probes in the right place to rewrite PROM, to force your choice of software back onto the device.

If you get the failure when trying to boot Android, and you have to use Odin to restore the approved bootloader, and you are able to use Odin to restore the approved bootloader, and then you can boot, then there is a software solution. But you would probably have to crack their signing protocol to create a bootloader that claims to be the right revision, and yet allows you to do what you want. I think you could solve the challenge of burning a PROM more easily than you could crack Samsung's encryption.

In download mode, when i use Odin with S3 rom, i received "sw rev check fail fused 5 binary 3".
I will research more.
Many thank you.

 

[Minionguyjpro]

I upgrade A8 T295 from T295XXS3ATB2_T295OLM3ATB2_XEV_9.0 to T295XXS5CWA1 by Odin. Success to upgrade.
When i want to rollback to T295XXS3ATB2, i received message: "sw rev check fail fused 5 binary 3".

How do I do to rollback to T295XXS3ATB2? or setup T295XXS3ATB2 again to root with Magisk?

Many thank.

You should be able to downgrade your firmware, but it requires wipe of a few things. Actually l, I heard from multiple sources it was possible.

 

[Minionguyjpro]

tried both and no success either way, I selected a Samsung as a car based tablet because I genuinely thought it would be the most supported device brand to configure. Seriously concluding why do I bother as nothing is straighforward. It would less stress just listening to crackly FM radio as can't see me getting this device to behave like a car head unit. I've successfully got a stock LG G5 phone running as a car based unit that switches on/off etc without my input. Only problem with that is its too small screen'wise

Like they have Apple stores in all major cities, kinda wish I could take in this tablet to a Samsung store and get an in-store expert make it car friendly :-/

What exactly goes wrong at the installation of the auto boot part? Let's include a screenshot where possible, and some text???

 

[Minionguyjpro]

tried both and no success either way, I selected a Samsung as a car based tablet because I genuinely thought it would be the most supported device brand to configure. Seriously concluding why do I bother as nothing is straighforward. It would less stress just listening to crackly FM radio as can't see me getting this device to behave like a car head unit. I've successfully got a stock LG G5 phone running as a car based unit that switches on/off etc without my input. Only problem with that is its too small screen'wise

Like they have Apple stores in all major cities, kinda wish I could take in this tablet to a Samsung store and get an in-store expert make it car friendly :-/

We'll get atleast a few things to work, I'm very sure about that.

 

[tamtc84]

You should be able to downgrade your firmware, but it requires wipe of a few things. Actually l, I heard from multiple sources it was possible.

Please tell me how to do it.
Current, i still search to do it but it still error.

 

[Minionguyjpro]

Please tell me how to do it.
Current, i still search to do it but it still error.

You could try to flash the latest TWRP if it works and then try to flash the firmware. By the way, it may not be possible to downgrade, but you may be able to downgrade to another firmware with the same binary version? And also, why are you downgrading?

 

[Talich52]

Please tell me how to do it.
Current, i still search to do it but it still error.

Do not torment the device and do not suffer yourself - Google & Samsung forbade downgrading the bootloader version, that is, with version 4 or 5, do not install version 3. In addition, bootloaders 4 and 5, even unlocked, do not allow you to install any custom files, such as a patched kernel or recovery TWRP. All questions to Samsung, but support for the device is over by the manufacturer...

 

[ebod]

I think you are wasting your time trying to eliminate the nag screen before you address the real issue.

Getting the tablet to automatically boot when power is applied is going to involve manipulating the filesystem. I don't think you're going to be able to just remount /system and edit something. That thread @Minionguyjpro found talks about unpacking the boot image and modifying it's ramdisk and repacking the boot image. That's a lot of steps where something can go wrong.

If you decide to live with having to push a button to boot the tablet, you will probably find that waiting for the nag screen to time-out is not such a big deal.

And it probably takes a lot of work to make the tablet shut down when you turn off the car. So, unless you go a long time without using the car, the tablet is already booted. At worst, you need to get past the lock screen. I haven't seen anyone talk about that. Maybe you just disable it in Android Settings.

I feel I've got further with a stock non-root LG G5 than I'll ever get with this SM-T295. That device literally starts on demand ( no bootlock warnings ) and auto shutdowns ( with help from Tasker /Autoinput ). I was just expecting once I got this unit rooted, it would be all just plain sailing. Its been anything but...
I have root, and I have the Magisk app on my device asking to let it update itself. However last time I tried it bombed out and I had to go back to square one.
I'll live with a stock Android 10 rom, in reality the device will just spend most of its life running Vivid launcher. So I just want to achieve a non-intervention turnkey startup in usb power as fast as is practical...preferably without the bootlock warning. I hoped this was a simple request that ANY novice could follow given clear enough instruction, but so far its been a combination of me being too dumb and nobody giving me a straightforward enough path to follow..

 

[Minionguyjpro]

I feel I've got further with a stock non-root LG G5 than I'll ever get with this SM-T295. That device literally starts on demand ( no bootlock warnings ) and auto shutdowns ( with help from Tasker /Autoinput ). I was just expecting once I got this unit rooted, it would be all just plain sailing. Its been anything but...
I have root, and I have the Magisk app on my device asking to let it update itself. However last time I tried it bombed out and I had to go back to square one.
I'll live with a stock Android 10 rom, in reality the device will just spend most of its life running Vivid launcher. So I just want to achieve a non-intervention turnkey startup in usb power as fast as is practical...preferably without the bootlock warning. I hoped this was a simple request that ANY novice could follow given clear enough instruction, but so far its been a combination of me being too dumb and nobody giving me a straightforward enough path to follow..

I once saw a flashable TWRP zip, but I should not flash it as some people bricked their device with it, I thought.

 

[Minionguyjpro]

I feel I've got further with a stock non-root LG G5 than I'll ever get with this SM-T295. That device literally starts on demand ( no bootlock warnings ) and auto shutdowns ( with help from Tasker /Autoinput ). I was just expecting once I got this unit rooted, it would be all just plain sailing. Its been anything but...
I have root, and I have the Magisk app on my device asking to let it update itself. However last time I tried it bombed out and I had to go back to square one.
I'll live with a stock Android 10 rom, in reality the device will just spend most of its life running Vivid launcher. So I just want to achieve a non-intervention turnkey startup in usb power as fast as is practical...preferably without the bootlock warning. I hoped this was a simple request that ANY novice could follow given clear enough instruction, but so far its been a combination of me being too dumb and nobody giving me a straightforward enough path to follow..

You could try to take a look at this:

How to remove carrier boot logo

Hello, What this post will be covering is in the title; I will be showing you how to remove the carrier boot logo off your samsung galaxy s21 ultra (This should work with pretty much any modern samsung phone) If you don't know how to flash a...

forum.xda-developers.com

 

[ebod]

I once saw a flashable TWRP zip, but I should not flash it as some people bricked their device with it, I thought.

I do have TWRP on the device. Though its pain to get to it with the nonsense bootlock warning message getting in the way lol.