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

[vidtek]

The device with this screen is in the Downloading firmware mode and it is waiting for uploading files via ODIN, so nothing changes
You need to flash the stock firmware T290XXU3CVG3 or at least the stock kernel and vbmeta. I will attach the file with them, try to flash it first by selecting the AP window. If the problem persists, then flash the full firmware T290XXU3CVG3.

Talich and Michael - Thanks once again both of you for your patience with this old fart. I was able to do as you said Talich although the Odin window said fail. It will now boot normally when disconnected from the power supply.
With my new root status I was finally able to modify the playlpm file and now when the usb power supply is connected it starts to boot but now it gets stuck on this screen attached and won't go any further. I have to manually press the power button until it shuts down, disconnect from the psu and then press the power button again before it will boot normally. This is the playlpm file I placed in /system/bin:

#!/system/bin/sh
/system/bin/reboot

Any ideas? Thanks Tony.

 

[Talich52]

Any ideas?

I won't tell you here, since I'm not a programmer, but just a user with a lot of experience... Look in the market, there may be a program for the necessary actions.
P.S. Perhaps this information will help: The device is easily routed with the Android bootloader 9 even on the latest firmware and works without problems. But there is one point - you can not charge the device when it is turned off, when the charger is connected, the device freezes on the screen, which is shown above. The loader is to blame for this, but I have not tried whether it is possible to install the loader 11 android, since my model is T295 and the loader is already 4 versions, which can no longer be replaced with version 3. The model also has a T290 loader on Android 11 version 3 and maybe a replacement will turn out...
Good luck!

 

[J.Michael]

Talich and Michael - Thanks once again both of you for your patience with this old fart. I was able to do as you said Talich although the Odin window said fail. It will now boot normally when disconnected from the power supply.
With my new root status I was finally able to modify the playlpm file and now when the usb power supply is connected it starts to boot but now it gets stuck on this screen attached and won't go any further. I have to manually press the power button until it shuts down, disconnect from the psu and then press the power button again before it will boot normally. This is the playlpm file I placed in /system/bin:

#!/system/bin/sh
/system/bin/reboot

Any ideas? Thanks Tony.

I don't know what the playlpm file is.
You should not modify the system partition. Sometimes it works, sometimes not. Magisk makes it possible to virtually "replace" a file -- you should look into the (very little) required.

So we're back to playlpm: Was there one before you changed it? What did it say? Why did you modify it?

 

[bingo1951]

T295XXU4CVG3 ????????????????????????????

 

[Talich52]

T295XXU4CVG3 ?

There is a version 4 bootloader in the firmware, which cannot be replaced with a version 3 bootloader from Android 9 - there is a ban on lowering the bootloader version from Google and Samsung. Bootloaders 10 and 11 of Android have enhanced protection and even with an unlocked bootloader, you cannot install a custom (patched) kernel or recovery (TWRP), that is, get Root rights

 

[bingo1951]

Nel firmware è presente un bootloader versione 4, che non può essere sostituito con un bootloader versione 3 di Android 9: è vietato ridurre la versione del bootloader di Google e Samsung. I bootloader 10 e 11 di Android hanno una protezione avanzata e anche con un bootloader sbloccato, non è possibile installare un kernel o un ripristino (TWRP) o ottenere i diritti di root

grazie

 

[vidtek]

I don't know what the playlpm file is.
You should not modify the system partition. Sometimes it works, sometimes not. Magisk makes it possible to virtually "replace" a file -- you should look into the (very little) required.

So we're back to playlpm: Was there one before you changed it? What did it say? Why did you modify it?

There are 2 files in the /system/bin directory that affect the charging regimes of all tablets/phones. /system/bin/lpm is the one in the firmware I have in my system. It was a binary file and I had a look in a hex editor and it was quite a complex affair, detailing how long the charging should take and what happens when the charger is plugged in. /system/bin/playplm is a similar file, but very much smaller with less options. These are the files to modify to make the tablet/phone boot on charger connection. My system just had the single file /system/bin/lpm file so I renamed that to /system.bin/lpm.bak and copied my modified version of /system/bin/playlpm. I did modify the playlpm file to read this:

#!/system/bin/sh
su
/system/bin/reboot

The original /system/bin/lpm file has over 2000 lines of code.
Tony

 

[Talich52]

Tony

I believe that the changes do not work, since the current bootloader is from android 9, with which the device does not charge in the off state. Try to replace the bootloader with a regular android 11, I attach the file.This is a BL file and first unpack it from the zip archive to .tar.md5, select BL or AP in the window and flash it. If there is a problem with startup or Root rights, then flash back the file aboot_vk_T290XXS3ATF1.tar, which I posted above, and I will attach it again.
Good luck!
PS in another related topic, they assured me that the T290 can be rooted with the Android bootloader 11, but I can't check it because I have 2 devices, but the T295 models. Try it and if anything, return (flash back) the bootloader 9 android...

 

[vidtek]

I believe that the changes do not work, since the current bootloader is from android 9, with which the device does not charge in the off state. Try to replace the bootloader with a regular android 11, I attach the file.This is a BL file and first unpack it from the zip archive to .tar.md5, select BL or AP in the window and flash it. If there is a problem with startup or Root rights, then flash back the file aboot_vk_T290XXS3ATF1.tar, which I posted above, and I will attach it again.
Good luck!
PS in another related topic, they assured me that the T290 can be rooted with the Android bootloader 11, but I can't check it because I have 2 devices, but the T295 models. Try it and if anything, return (flash back) the bootloader 9 android...

Talich - I tried the file but resulted in the blue screen with red writing as posted in post #456 in this thread. I re-flashed all 4 files of the original
T290XXS3ATF1 that was originally on this tablet. Back to square one after another 3 days out of my useless life.....

 

[Talich52]

Talich - I tried the file but resulted in the blue screen with red writing as posted in post #456 in this thread. I re-flashed all 4 files of the original
T290XXS3ATF1 that was originally on this tablet. Back to square one after another 3 days out of my useless life.....

I suppose it was enough to flash the android 9 bootloader back, that is, the aboot_vk_T290XXS3ATF1 file, and not go full circle. Unfortunately, such a dilemma is either Root-rights with the Android 9 bootloader, but then the charging of the switched off device does not work. But frankly, I don’t understand why they turn off the device, even if it eats up 2-3% of the total charge overnight?
But in general, every evening I put the device on charge without turning it off ... The battery is in excellent condition
P.S. I made a mistake by recommending to flash the full file of BL bootloaders for android 11! there was no need to return the vk file (vaultkeeper.img), and we also returned the original vbmeta file, and did not leave the patched Magisk. If you have the strength and desire, then repeat everything, but only flash the aboot.mbn file for Android 11, which I will attach for installation via ODIN.

 

[vidtek]

In the end, I have flashed it all back to as it was when I bought it and then took every modified file I could find and flashed that into the BL and AP slots.

The result is a rooted tablet with magisk and twrp installed and it now boots when the power is applied.

I have no idea which file did it, I must have flashed about half a dozen, but I got the result I have been looking for - yay!

I should have taken more care and documented each stage which is what I normally do, but I was past caring and just went for it.......

Thank you to all on this thread, particularly Michael and Talich.

 

[J.Michael]

In the end, I have flashed it all back to as it was when I bought it and then took every modified file I could find and flashed that into the BL and AP slots.

The result is a rooted tablet with magisk and twrp installed and it now boots when the power is applied.

I have no idea which file did it, I must have flashed about half a dozen, but I got the result I have been looking for - yay!

I should have taken more care and documented each stage which is what I normally do, but I was past caring and just went for it.......

Thank you to all on this thread, particularly Michael and Talich.

It's a pretty safe bet that only the last file flashed to each partition matters. But if you took a flock of tar files and ran Odin using two tar files at a time, it's hard to predict what came from where -- AP and BL are not partitions, they are just the way Samsung organizes their firmware delivery. Each tar file contains one or more files, each of those files is a partition image.

Can you identify the half-dozen files you flashed, and check their contents to see if any partition names are duplicated? And maybe check to see if the duplicated names' files happened to be identical?

 

[vidtek]

It's a pretty safe bet that only the last file flashed to each partition matters. But if you took a flock of tar files and ran Odin using two tar files at a time, it's hard to predict what came from where -- AP and BL are not partitions, they are just the way Samsung organizes their firmware delivery. Each tar file contains one or more files, each of those files is a partition image.

Can you identify the half-dozen files you flashed, and check their contents to see if any partition names are duplicated? And maybe check to see if the duplicated names' files happened to be identical?

Michael - I had wondered about the names Odin uses to separate files as it seems BL and AP are interchangeable in some cases, that led me to suspect what you have said about being unrelated to actual partitions. It will take me a while to go through the files unpack them and get the information you require. It will obviously help everyone to know what is what, please be patient it will take me some time to gather the information-I should have done my usual documentation...doh!

 

[Talich52]

I have no idea which file did it, I must have flashed about half a dozen, but I got the result I have been looking for - yay!

Congratulations on solving the issue If it is not difficult, then install the attached program and make a screenshot of the Firmware Information tab. It may have been possible to root the device with the android bootloader 11 and therefore the charging works in the off state. By the name of the loader, it will be clear that it is from android 9 or 11... Thanks!

 

[vidtek]

Looks like I spoke too soon, this morning when I switched on the ignition (or whatever you call an EV power up state) and power was applied to the tablet I got the ususal hang with the Samsung logo. Previously it must have been actually switched on so fooled me into thinking it was powering up properly...sigh....silly old fart should have known it wouldn't be that easy.

 

[vidtek]

Talich - here are the screenshots from your programme.

Given root rights and inserting my /system/bin/playlpm file; the system still hangs on boot whenpower is applied. I ensured the file has the correct attributes w+r+x

Tried deleting the /system/bin/lpm file but it refuses to budge. Perhaps if I could get rid of that I may be able to sort the boot hang.

Now stuck ...... again!





Tony

 

[J.Michael]

Talich - here are the screenshots from your programme.

Given root rights and inserting my /system/bin/playlpm file; the system still hangs on boot whenpower is applied. I ensured the file has the correct attributes w+r+x

Tried deleting the /system/bin/lpm file but it refuses to budge. Perhaps if I could get rid of that I may be able to sort the boot hang.

Now stuck ...... again!





TonyView attachment 5733741View attachment 5733751

What is this "playlpm" file? Why are you messing with it? How did you mess with it?

Have you searched the site? Google led me to this thread where @callumw was ultimately successful.

 

[vidtek]

What is this "playlpm" file? Why are you messing with it? How did you mess with it?

Have you searched the site? Google led me to this thread where @callumw was ultimately successful.

Michael, thank you for helping. The playplm file is exactly as Callum posted, I have tried both versions, as I posted in #487 this thread. It would seem to me that Samsung have messed around with this new /system/bin/lpm file (which doesn't seem to appear in older devices), extending the functionality to cover all sorts of eventualities with charging instead of the playlpm file which is not there at all. I have searched every site under google and duckduck with no joy.

My issue now is I seem unable to move/delete/rename the /system/bin/lpm file. It just stubbornly refuses to be tampered with, even though I have read/write and root rights for this folder. Just weird, I use Linux; I am comfortable with the cli and simple programming, rarely resort to Windows although there is no decent equivalent for Odin so use a VM to flash files in Odin with win 8.1. I have tried ES and Total Commander maybe there is another root file manager you could recommend for Android?
Cheers Tony

 

[J.Michael]

Michael, thank you for helping. The playplm file is exactly as Callum posted, I have tried both versions, as I posted in #487 this thread. It would seem to me that Samsung have messed around with this new /system/bin/lpm file (which doesn't seem to appear in older devices), extending the functionality to cover all sorts of eventualities with charging instead of the playlpm file which is not there at all. I have searched every site under google and duckduck with no joy.

My issue now is I seem unable to move/delete/rename the /system/bin/lpm file. It just stubbornly refuses to be tampered with, even though I have read/write and root rights for this folder. Just weird, I use Linux; I am comfortable with the cli and simple programming, rarely resort to Windows although there is no decent equivalent for Odin so use a VM to flash files in Odin with win 8.1. I have tried ES and Total Commander maybe there is another root file manager you could recommend for Android?
Cheers Tony

You are generally advised not to try to change /system. Magisk has a facility that enables "overlaying" or "masking" files, but it only works when Magisk is active. I think I've also seen cautions about when in the boot process a file will be used -- Magisk can't "mask" until past a certain point.

The talk about using a shell script makes it seem there is an Android running when you think your device is shut down. And it uses at least some files in /system. So the question becomes "what boot image is it using?"

Have you tried making a Magisk module to replace this file?

Did you try the instructions involving remounting /system? (After reading Wu's warning that just remounting could trip the tamper protections?)

 

[vidtek]

You are generally advised not to try to change /system. Magisk has a facility that enables "overlaying" or "masking" files, but it only works when Magisk is active. I think I've also seen cautions about when in the boot process a file will be used -- Magisk can't "mask" until past a certain point.

The talk about using a shell script makes it seem there is an Android running when you think your device is shut down. And it uses at least some files in /system. So the question becomes "what boot image is it using?"

Have you tried making a Magisk module to replace this file?

Did you try the instructions involving remounting /system? (After reading Wu's warning that just remounting could trip the tamper protections?)

I haven't tried making a Magisk module, no. Wu's warning? Can you tell me where to find it please?