[Galaxy Tab 4 Q&A, Help & Troubleshooting] lm089:
Hi,

the other day a friend gave me her old Samsung tab 4 7.0 (SM-T235). It's in its default state, running Android 5.1.1 stock ROM with all the most recent (5 year old) updates. "KNOX" appears to be ok, afaik.

This is my first Samsung device, up to the date I had experience with HTC Desire, Sony Xperia (2x) and OnePlus devices. I unlocked / rooted and installed custom ROMs on all of them.

Done quite a bit of googling and playing around with my "new" Samsung to see where it's different compared to my other devices. But there still are some blank spots, and there doesn't seem to be too much information out there regarding that specific tab 4 device. Before I start messing around I'd love to have some input from experienced Samsung users in regards to custom recoveries and ROMs, and possibly rooting. If there are comprehensive guides etc. out there that I simply didn't find don't hesitate to give me some hints:

First of all it appears to me that this device is going under the codename "degas". Correct? (meanwhile confirmed)

I hooked up the device to my PC, made sure that adb found it alright, then called "adb reboot recovery". That worked nicely, got me into Samsung recovery

Next I again tried to connect through ADB to the device still being in recovery, but that didn't work. To be expected?

Still in recovery I chose the "boot to bootloader" option, but that got me back into system instead.

So from system I again connected to adb then called "adb reboot bootloader". Device booted alright, but again it just rebooted into system.

>> Is there really no way to get into bootloader?

Trying to find out what has to be done in order to flash a custom ROM (rooted or not): from what I get, and unlike my other devices, I do not have to unlock the device / bootloader to begin with. It looks as if it was sufficient to boot into what they call "download mode", then hook up the device to my PC where ODIN is waiting already. Following this thread (and others) it then is sufficient to just flash TWRP from ODIN, boot to recovery and then do what is usually done here (like flash custom ROM, flash Gapps and possibly Magisk etc.). Is there something else / important I should know / observe?

Speaking about TWRP and Custom ROMs: TWRP.me lists that device on their site. So has anyone here flashed latest TWRP (3.6.2_x)? Or should I rather start with an older version like the one listed here, then possibly upgrade from there?

In regards to Custom ROMs I basically just found this LOS 16 thread (which is the same linked in the previous "TWRP" bullet). I assume that's it, or does anyone know about a newer android version (which I didn't find so far)? There seems to be lots of activity around "matisse" and "millet", but apparently those aren't the right devices, right?

Back to recovery: I see that in stock recovery there is an option to "wipe data/factory reset": should I do that before flashing TWRP from ODIN, or is it sufficient to wipe everything once I booted into TWRP?

I'm aware that I'll lose "Knox" as soon as I flash a different ROM / Recovery. As I don't want to use the tab 4 in some critical "BYOD" area I don't care (neither do I care about warranty, that's long gone anyways). But just to be sure: is it true that I'll lose "Knox" access?

In case I would decide to "go back" to stock ROM one day, how would I proceed then? Would ODIN still work so that I can flash latest stock ROM? Would Knox then be restored, or is that a thing of the past once I leave the stock ROM path?

Again: if you think I've done a bad job searching for answers don't hesitate to let me know but please be so kind then to hint the phrases I should look for ("SM-T235" really doesn't bring up that much valuable info)

Thanks and cheers

Update 2022-08-03: meanwhile I realized that the device is connected to my PC through generic drivers. Would it help to install specific Samsung drivers although both ADB and ODIN are acknowledging the device? Or can I just neglect that?