yashsingh1/xdaforums huggingface dataset:
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
The whole problem is the discrepancy between the bootloader and the system - the bootloader is version 3 of the 9 android, and the system is 10 or 11 android. And in this case, there is no normal animation of charging the switched off device and freezing it when trying to start it.

Clarification on the modem, the practical conclusion is this - now you can not run the full TI4 firmware until you replace the CP modem file with the CP file from the T295XXS5CWA1 firmware. I'm sorry I didn't warn you earlier.
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
What have you done to make it auto-shutdown when there is no usb charge power? That is not normal behavior -- I think it is normal for shutdown/boot to be completely disconnected from charging power.

Wouldn't you be better off with the tablet staying on after you turn off the car? Then, when you turn on the car, you won't have to wait for it to boot, you won't go through the nag screen.
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
It must be possible when booted into the system using an app or so... much better possible with apps.
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
If your issue just keeps on going, I recommend to just install LineageOS. AS I said, I had the same type issue and fixed it by installing it.
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
Oh, and @ebod, the LineageOS 20 ROM doesn't include cellular/LTE support, but maybe you need that???
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
I've done this on a pilot project with an old LG G5 phone using an app called Tasker. I hear your point about not shutting down but the car in question isn't my daily use car, its a spare car I use for rare sunny days in the UK ( Volvo C70 convertible ). I just wanted to have it running like a modern car head unit with minimal intervention. I don't want to park the car up for weeks and forget about the fact the tablet is draining its battery.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
I can work around that by making my cell phone trigger wifi hotspot when it bluetooth connects to the car, however I would still prefer to have everything working as it should. So is this just a LineageOS 20.0 issue or all older versions too?
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
OK thanks, noted on both points. For sure rom TI4 is thrown out the window now and WA6 with the Android9 bootloader is in play. I will pursue root based on that.
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
All, because the feature was not included.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Looks like I'm just going to stick with a rooted WA1 stick rom then. Just need to progress to root now that I know all the other oddities I've experienced are due to an Android 9 bootloader file
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
I mean that cellular data is the only feature that is not included on LineageOS, because it was actually made for SM-T290 but appears to be working completely on an SM-T295 too.
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
You can also install the TI4 firmware, but only part of the AP & CSC, and the CP modem only from the T295XXS5CWA1 firmware, as well as the modified T295XXS5CWA1_OS9 bootloader, otherwise Wi-Fi does not work.

Well, either entirely WA1, with the same modified bootloader.
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
Are you able to update the TWRP to v3.7.0 for the SM-T295? I don't have it, but some people may find it nice if you plan to update the version of TWRP!
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
You can. Posted on the forum xda TWRP 3.7.0 for T290 works fine on T295 :) https://xdaforums.com/t/recovery-unofficial-twrp-3-7-0-for-2019-galaxy-tab-a-8-0-sm-t290.4185235/

It is enough to delete 2 extra files for T290, leave only recovery & vbmeta, attached below.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
UPDATE : I'm now sat with a stable rooted WA1 stock rom and opting to not take the lineage route due to lack of LTE. I have LTE/Wifi, just got the odd side effect of freezing charge animation screen when shutdown on charge.

My continued focus will be on :-

> Removing bootlock unlock warning and speeding up boot

> Triggering an auto-start when USB power connected

> Any possibility to replace Samsung startup logos with car brand logos eg Volvo ( nice to have only )

Some of above have been touched on in this thread, but perhaps its a distraction to its main topic of achieving root. Should I start a fresh post dealing with above?

Thanks for the support to get me this far.
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
Animation files when loaded at /system/media. 2 files - bootsamsung.qmg & bootsamsungloop.qmg. Can be replaced via TWRP.
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
I recommend installing the latest firmware 9 android, specifically sewing only AP & CSC files. The bootloader and modem leave the current WA1. Then the animation of the charge of the switched off device works correctly.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
OK So when I started with my device it was on TI4 which was Android 10 with rom TI4. I've followed all instructions/guidance to install WA1 EXCEPT for its BL file ( instead used your modded OS9 one...hence confused a little when you mention "leave the current WA1 bootloader" ).

So to get a normal charge animation behavior...I imply go to SamFW and get the "UA6" batch of files and then on ODIN, I flash ONLY the UA6 AP & CSC file?

Will that literally be all I do?.....or eg will it mean I'll lose root and hence have to re-install the TWRP file via the AP port again and re-install multidisabler.zip & magisk.zip again via TWRP? What is the full scope here ?

Thanks for the continued guidance.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Thanks, understood there are two files, unsure how to use TWRP to carry out this extracting and replacing. Any further guidence available on the methodology ?
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
https://samfrew.com/ru/model/SM-T295/region/BTU/

UA6 is Android 10, the latest Android 9 firmware is T295XXS3ATB4.

Install AP & CSC parts only. And re-root. Install TWRP, you can version 3.7.0 posted above. From TWRP install multidisabler, do format data-yes; install Magisk.zip; boot into the system. Loading minutes 6 .
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Ahh OK clear, will do this eve when back home from work. Also double clear about "TB4" being final Android 9 rom. Will use the later 3.7.0 TWRP too
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
TWRP has a built-in file manager, so use it.
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
Yes everything is correct. Let me remind you once again that now the modem cannot be installed with a lower version, and accordingly the bootloader must be WA1 modified.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
..will explore this avenue soon, i.e. finding out what editor works with 'qmg' files and which are static and gif type looping. Hopefully somebody smart has already created 'Volvo' logos I can just rename and drop in.

On a parallel issue I have a China made vertical mounted 'tesla style' android head unit in my GM Astra J car. Its based on a "YT5760B" model. I only wish I could find more support to mod/update this unit to improve it.
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
Hmm ... on firmware 9 android RootExplorer works without problems, but on 11 android it was impossible to edit files in / system. On Android 11, I was forced to replace files through TWRP.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
@J.Michael did this mumbojumbo just make any sense regarding the param.bin file which I believe was the path to remove the unlocked bootloader warning? Thats now back on my agenda again
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
I think I'm the wrong person for you to be talking to.

The screenshot you posted shows you using the "-l" switch on an "ls" command, so we can see you have two more directories with cryptic names. Maybe what you want is in one of those directories. Since the names have numbers, it may be important which you pick.

I glanced at the thread @Minionguyjpro directed you to regarding extracting the param.bin file. It involved using the "dd" command to copy from some partition -- what was copied is being called "param.bin". I didn't read the whole thread, I don't know what format "param.bin" is in; it may be it can be considered a ZIP file.

I have no idea what you intend to do with "param.bin" once you get it.

As long as you are careful not to mix up "if" and "of" ("input file" and "output file") in the "dd" switches, it costs nothing to try reading a partition to see what you find.
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
He wants to delete/replace the bootloader warning images, so the annoying part is gone.
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
Try the same thing. Find yourself a custom ROM to install on it. I recommend you to pick OFFICIAL versions, as they are updated atleast regularly. By the way, what is the Android device? I can look for some stuff.
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
The param.bin file is located in the mmcblk0p47 section, which is 12Mb in size. I copied this section with the TWRP file manager to the device's memory. I see that it is almost empty and what should I edit there ?!

P.S. and I returned to Android 11 on WA1 of course with Root rights. Something 9 android some flawed;)
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
haha hell no! :) It took me all these days just to settle on a stock rom that I could root. I'd only ever look at a custom rom if it gave the device all the features it came with..i.e. LTE.

So for me , no1 = auto start on usb power , no2 = remove annoying unlock warning , no3 = custom splash animations with Volvo logo.

The other device I mentioned ( YT5670B ) is in my daily car ( GM Astra J ) like this :
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
Nice. Are you still thinking about install LineageOS 20 on the SM-T295? It only hasn't the option to use LTE connections, but you said you could make a hotspot or something, so it is achievable...
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Guys , I've now got Tasker installed and shutdown when charge removed is a setup task ready to roll.

Can I seek some skilled support on the 'auto-start-on-charge' state to make my SM-t295 car friendly.

I've found these threads and concluding its a trodden path for other Tab users :-

https://xdaforums.com/t/q-auto-start-when-connect-to-charger.3094768/

Automatically power on Android when the charger is connected

Is it possible to automatically power on the device once the charger is connected given that the device is initially turned off?

android.stackexchange.com

...but I'm simply not smart enough to grasp how to do this on my Tab.

When the authors are instructing about edit/copy etc, by what means are they doing this? Is it all via the ADB screens?

If someone can interpret what these posts are saying and then decipher this into simple instructions for me to follow...I greatly appreciate.

This is my limit :-

Thx
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
On Samsung, there is no "fastboot".

Start by seeing if you even have a "lpm" or "playlpm" file in /system/bin".
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
I tried TWRP file manager earlier and I swear It didn't display a system folder ( only system_root ) , anyway I allowed it to install the TWRP app on the device and gave it superuser permissions.

Now when I boot into TWRP and look again...there is a system folder....yes I see "lpm" !

Also seen this on YT but not sure what app is being used to edit
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
When I say try a command like "ls", I mean in a terminal on the tablet. The way you did it earlier, using ADB shell, is just as good.

In TWRP, I don't know what partitions are mounted. You are now in a position to find out. That probably explains why you didn't see "/system". I thought I remembered TWRP having an option like "mount /system".

I don't know why "nano" would be available, and I don't know why you get the error you get.

In the video, he clicks a line that says "ES Note Editor", so I'm guessing he's using ES File Explorer as his file explorer. The only important thing about that is where he is careful to select just a line feed as a line terminator (as opposed to CR/LF, which is the default in the DOS/Windows world).

The guy in the video apparently has a system where he is free to edit files on /system. He doesn't say what system he has, or what he has done to it. This is not always possible. Some people are able to remount /system and have at it. Other people try and just trying causes their device to bootloop. The fact that you are writing what look like shell commands in this file makes it look like, at the moment we are talking about, *some* system -- capable of opening a shell -- is already running. I don't know what system it is, or where it is buried, so I don't know whether it is happening after Magisk does its magic. So I don't know if using a Magisk module to overlay the "/system/bin/lpm" file would do you any good.

I can imagine you unpacking your AP.tar and managing to edit the "/system" filesystem, then repacking it and flashing it, but you're at the mercy of a bootloader released by a company that is determined to take any excuse to refuse to run a system it does not deem to be "valid". I think you are asking for trouble.

Did you read through the comments to the video? There was a list of addenda in the "show more" of the summary. One line said someone had an update for making this change on a modern system. Almost the last comment seems to be that update. As you work through the comments you'll see a lot of "ES File Explorer is no longer available", "this didn't work for me", and a few "you da man".

TL;DR Until I see @Talich52 say otherwise, I do not believe you can edit "/system/bin".
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
It looks to me that I have 3x 'potential' methods. i) Via a connected PC using the ADB Shell , ii) via the TWRP file manager , or iii) via a file manager/editor app on the device.

I'd prefer to copy/paste verbatim command lines that you or @Talich52 fed me.

I have found an apk browser called 'Root Browser' that I can navigate to system on the device, but I can't seem to be able to find further apks to open/edit files.

I think the trouble with much of this historic guidence we look up is that it might have been the ideal solution ~6yrs ago but things change over time, so you can never be sure what someone writes historically remains a valid solution in early 2023.

Thanks again for your ongoing patience.
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
Why you guys cannot edit /system? I can edit any file with Magisk's root, and I use 'Rot Explorer', and that works in-system.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
I tried a few explorers and presently have "Root Browser" installed. It can readily access system and navigate to the lpm file, however difficulty comes when selecting the file that there is no suitable editor.

I can see your referenced "Root Explorer" app but its a paid one. If I know its the only app that will fully do the job and there is no free alternative then sure I will take this option. Is it???

I thought the real issue here is an editor app rather than an explorer app...
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
No, I heard you can also use ES File Explorer, which is completely free. And you can also install any text editor like Quickedot
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Tried Quickedit and also one called Totalcmd-Editor and both had permissions/java issues ( both granted SU)

I've heard of ES explorers for long time...but like I said on my previous post..times change and what worked once..may not work as of Feb23
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
Here is TWRP 3.7.0-11, there is a system mount.
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
I wrote above that RootExplorer on Android 9 works without problems with / system. On Android 11, the system partition itself is not transferred to r / w mode, but it turns out that / system / bin switches to r / w mode and you can do something. Try :)
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Hi @Talich52 , I've installed this apk and can do exactly as you have done. This concludes with opening the lpm file with the text editor option to display a heap of random characters.
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
The lpm file is some binary image, some program, I do not know what it does.

The video you linked earlier said

rename lpm to lpm.old

create a new file named lpm

Once you rename "lpm", there is no "lpm", so you can create a new "lpm". You will create a text file. You will type the few lines somebody suggested. You will pay attention to how lines end -- someone somewhere said carriage returns would stop it from working.

If you can really use TWRP to modify /system/bin, and it TWRP provides a text editor, there is a very good chance that it will end each line with a single line feed, which is what you want.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Unfortunately I hit another brick wall here, I can use TWRP to locate/copy/rename the lpm file or shift to another place. But no option to create a new file, and when attempting to edit , its so restricted that it can't delete lines.

Its almost as it I need a 'heres one I prepared earlier' lpm file to drop into my system/bin folder.
[Samsung Galaxy Tab A series Guides, News, & Discus] Talich52:
I wrote above and I will repeat it again - I recommend to roll back to Android 9. Flash only the AP & CSC file. Rollback only with data reset. Then you can adjust everything in /system RootExplorer :)

And the charging will work in the off state, or rather the animation of this process will be.
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
So make one.

When I open a terminal window on my tablet, I have a "vi" available -- it's an old UNIX text editor. It's painful, but adequate to create a two-line text file. I assume "vi" is provided by the busybox that came with Android 9 on my tablet.

You could install Mixplorer and use its text editor. (Or its Code Editor -- I'm not sure what that would buy you, other than using a fixed width font, which I prefer.)

You could create the file on your desktop computer. If you have Linux, either as a primary installation, or in a virtual machine under Windows, you can use whatever text editor they make available. You could run a Live-CD (maybe Live-USB these days) to get a Linux just long enough to make a file and figure out a way to copy it -- probably to a USB drive.

Under Windows, I think Notepad++ lets you specify how you want lines to end. The newer version of Notepad can be forced, but you need to do something in the registry.

If you don't already have a Linux available, I think your best bet is to use the command window (terminal emulator) and create a file somewhere easy to get to. Make sure TWRP can see a place like /sdcard (or your external SD-card). Then open a terminal window and use "vi":

prompt> vi newlpm.txt
inow you are in input mode
hit enter when you want a new line
<ESCape>ZZ

If you don't have "vi", or can't stand to use it, you can use "echo" to write to a file -- no editing, you have to do it right the first time:

prompt> echo whatever you want for the first line > newlpm.txt
prompt> echo the second line >> newlpm.txt

A single greater-than sign (">") will delete any existing file and write the line to a new file by that name.

A double greater-than sign will append to an existing file.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
I'm sure I have done this as you stated. i.e. right now my charging animation is fine. When I get home from work later today , I will study latest reponses and try to progress further.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Will study when back home, I can see the Mixplorer app on marketplace but Echo & Vi don't draw any results that make sense to me as editor apps. Also at this juncture, the only terminal editor I'm aware of on the tablet itself is via TWRP, its that what you meant?
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
Mixplorer is an Android app. It is also available here on XDA.

I mentioned "echo" and "vi" as "commands", programs available when running a "shell", a terminal emulator window. You would need to get a terminal emulator app from somewhere like Google Play Store. I use Jack Palevich's "Terminal Emulator for Android"; a lot of people seem happy with "Termux". The point is it gives you a chance to type commands on your tablet, the way you type in a terminal window on Linux, or in a Command Prompt window in Windows.

Maybe you could describe what kinds of systems you have used, and what you have done with them.
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
I'm a total novice here, literally only understand to open up a command prompt in windows and recently as a result your continued support from this thread have ID'd that TWRP has a terminal option. I've never done any command scripts inside Andriod itself , hence need intensive support to steer me. As I'm conscious I'm being a pain/needy, it might prove easier to share a ready baked modded lpm file to me to drop into my system/bin folder.
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
Here is an alternate approach. It still replaces the "lpm" file, but it has a different way to trigger the boot.

Try typing "echo Hello" in TWRP's terminal.

Then type "echo in a file > z.txt".

Them see if you have a file "z.txt". (Type "ls -l")
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
This occurred:-/

VVVVVVV
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
Here's the result, only syntax is the initial hello didn't have a capital H...would that matter?
[Samsung Galaxy Tab A series Guides, News, & Discus] ebod:
STOP THE PRESS!! I've got there (auto-start that on usb power that is ).

I jumped onto this thread @Post #212 and got schooled to a successful outcome.

https://xdaforums.com/t/q-power-on-when-plugged-in-boot-when-docked.1187631/post-88174527

So left on the list is trying to replace Samsung boot animations with VOLVO ones...and that damned annoying bootloader unlock warning...gawd I'm sick of seeing that!
[Samsung Galaxy Tab A series Guides, News, & Discus] J.Michael:
In reverse order:

Congratulations. How you can navigate the process of unpacking/modifying/repacking a boot image, reassembling the initial ramdisk on the way, but you can't make a text file is beyond me.

The command to list files is "LS -L", except all lower case.

The point of the exercise was to demonstrate a way to create a text file. A second "echo" command, this time with a double greater-than (">>") would result in appending the second line to the existing file.

Since you've downloaded Notepad++ to your Windows machine, you are probably past caring.

I have no idea what to do with "VVVVVVVVV" (I didn't count).
[Samsung Galaxy Tab A series Guides, News, & Discus] Minionguyjpro:
You can also speed up loading by adding a few lines to the build.prop file in /system. I've made a post about it like 1, 2 or 3 pages ago.