[Galaxy Tab S2 Android Development] retiredtab:
LineageOS 20 UNOFFICIAL for 2015 Samsung Galaxy Tab S2 SM-T810 ONLY

Model: SM-T810 (wifi) - gts210wifi - 9.7" screen, Exynos 5433 SoC, no LTE

This is the ONLY model that the ROM will work on.​

You MUST READ posts 1-4 (about 10 minute read) before deciding to install this rom. If you think this is an unreasonable request, then stop reading now and find another rom. Thank you.

DISCLAIMER

I am not responsible for lost data, identity theft, lost money, security vulnerabilities, bricked devices or any other hardware or software malfunctions that comes as a result of flashing this rom.

All involved in bringing this build to you are working voluntarily on it in very limited spare time, and their other life commitments have much higher priority. Don't expect a prompt, or even any, response to questions and bug reports.

Before attempting to install this ROM

1. Ask yourself: would bricking your device be a disaster for you? If yes, don't try this ROM! It can't be guaranteed stable and reliable enough to depend on for daily use.

2. BACKUP YOUR DATA AND EXISTING ROM. Be prepared for a complete restore if anything goes wrong.

3. RESEARCH adb, fastboot, Odin/heimdall, and TWRP and how to use them, if not already familiar with these.

What works

1. bluetooth

2. wifi

3. brightness

4. external audio

5. GPS

6. audio through headphone jack

7. audio over bluetooth

8. selinux enforcing

9. DRM level 3 (SD definition)

10. deep sleep

11. camera

What doesn't work/What hasn't been tested

1. fingerprint is completely removed in 19.1. When I tested it in March 2022, it wasn't compatible with keystore2 and as I wrote in post 1891 at

https://xdaforums.com/t/rom-unoffic...t810-t815-t815y.3879302/page-95#post-85533725

it never worked properly after deep sleep. If you need fingerpint to work, stay with stock Samsung rom.

2. DRM level 1 (no HD definition). There's more detail in post 1891 above. I will not be trying to achieve level 1 for HD definition. If you need HD definition for your $treaming media, stay with stock Samsung rom.

3. full disk encryption has been deprecated in Android 13 (LineageOS 20).

4. If you charge the device while it's powered off and then want to power it on, you MUST wait at least 30 seconds AFTER disconnecting the charger cable before pressing the power button otherwise you might run into strange boot problems.

5. If you are repeatedly seeing “Connected to device. Can’t provide internet” (CPI), it's mandatory that you do a complete clean install including formatting data in TWRP and reinstalling all your apps. It's highly likely that CPI is because you did a dirty flash or one or more of your apps/configuration is messed up.

NOTE: Airplane mode has to be disabled in order to see this icon.

6. Device running really slow/laggy due to low memory. If you run a lot of apps that "phone home/connect to mothership", there's a possibility that it triggers a slow memory leak and the device, over time, becomes slow and laggy. You can see if you're low on memory by running

$ adb shell dumpsys meminfo

Total RAM: 2,827,980K (status critical)[/S][/S]
[S][S]Free RAM: 256,196K ( 53,728K cached pss + 87,128K cached kernel + 115,340K free)[/S][/S]
[S][S]Used RAM: 3,638,878K (3,067,642K used pss + 571,236K kernel)[/S][/S]
[S][S]Lost RAM: -346,213K
ZRAM: 671,040K physical used for 1,412,244K in swap (1,413,984K total swap)
Tuning: 192 (large 512), oom 184,320K, restore limit 61,440K

When the above shows "status critical", that's a sign of a memory leak and you may get CPI or slow/laggy performance. The only "fix" is to reboot. It should show "status normal" after a reboot.

If you're a developer, we could use some help here determining where the memory leak is.

7. gapps. Some of you require gapps for whatever reason. I use Aurora Store for my purposes and thus have NO KNOWLEDGE of the current state of gapps.

There are various gapps projects (at least 5 in 2023). Each has pros and cons. It's your job to do the research and find a suitable gapps project. I suggest you allocate at least a couple of hours/days doing your own research. My rom works by itself fine without gapps. DO NOT talk about gapps in this thread.

I have created a new 20 thread for those wanting to discuss gapps at

https://xdaforums.com/t/exynos5433-...sion-for-20-roms-sm-t710-and-sm-t810.4600455/

In there, you will find what pre ALPHA testers have been using.

I added this info to post #1.

8. Memory leak with Chromium based browsers. If you run a Chromium based browser like Chrome, Brave, Microsoft Edge, etc and open, close, open, close the browser app, there will be a memory leak of 30MB to 50MB each time. You can see this using adb below.

# open up a terminal/command prompt on your PC
adb root
adb shell
ps -A | grep -i zygote
# example output
$ adb root ; adb shell ps -A | grep -i zygote
adbd is already running as root
root 304 1 1733448 97000 poll_schedule_timeout b1fcd238 S zygote
webview_zygote 745 304 1749936 50592 poll_schedule_timeout b1fcd238 S webview_zygote
u0_a121 2499 304 1758944 49768 __skb_recv_datagram b1fccc10 S com.brave.browser_zygote
u0_a121 3405 304 1758944 49756 __skb_recv_datagram b1fccc10 S com.brave.browser_zygote

Over a period of 20+ days, this memory leak causes free memory to decrease and can lead to slower performance.

If you have root, you can kill these processes or simply reboot the OS to reclaim the memory. Firefox based browsers do NOT have this problem. In addition, the built in Webview engine does NOT have this problem. I use DuckDuckGo + Webview engine and there is NO memory leak.

9. Possibly other features/apps that I haven't tested or do not use.

Source Code

Kernel source code

https://github.com/retiredtab/andro...ersal5433-selinux/tree/lineage-20-8916-binder

See FAQ 1 for links to the device tree, manifest and build instructions in post #2.

Thanks

1. LineageOS team for source code.

2. LineageOS-UL team for merging, maintaining the legacy patches needed for old devices into one common repository so everyone can benefit.

https://github.com/orgs/LineageOS-UL/people

3. In alphabetical order.

@ananjaser1211

- answering 5433 related questions wrt to certain features.

@bmwdroid

- testing many pre ALPHA 20 builds and reporting the results

@lpedia

- testing many pre ALPHA T710 builds starting in late Oct 2022 and reporting the results

- verifying my build instructions work so that the technically inclined can build this from source

- building, maintaining and most importantly, testing the T710 20 builds before monthly security patches release

@metterschling

- suggestions, feedback on 20

- verifying my build instructions work so that the technically inclined can build this from source

@pflyaz

- testing many pre ALPHA 20 builds and reporting the results

@Yogi555

- testing many pre ALPHA 20 builds and reporting the results

- verifying my build instructions work so that the technically inclined can build this from source

- building, maintaining and most importantly, testing the T810 20 builds before monthly security patches release