[Samsung Galaxy Tab A series ROMs, Kernels, Recover] retiredtab:
FAQ - I spent hundreds of hours building this rom. It was frustrating process from Nov 2021 to Aug 2022 running into bug after bug. The least you can do is spend a few minutes reading everything before posting.

Q1. Where are the source and kernel source files?

A1. The kernel source files are at

https://github.com/retiredtab/android_kernel_samsung_msm8916

The device tree files are at

https://github.com/retiredtab/android_device_samsung_msm8916-common/tree/lineage-19.1

https://github.com/retiredtab/android_device_samsung_gt510wifi/tree/lineage-19.1

https://github.com/retiredtab/device_samsung_gte-common/tree/lineage-19.1

The vendor tree files are at

https://github.com/retiredtab/android_vendor_samsung_gt510wifi/tree/lineage-19.1

https://github.com/retiredtab/vendor_samsung_msm8916-common/tree/lineage-19.1

The manifest.xml (or roomservice.xml) and build instructions for 19.1 are at

https://github.com/retiredtab/LineageOS-build-manifests

Q2. Is this ALPHA rom suitable as a daily driver?

A2. It can be depending on your requirements. I can't test every app so you try it yourself to see if it's suitable. I've been using this rom myself since mid March 2022 with no major issues. I suggest you do a clean install, see FAQ 11, and flash this 19.1 ROM BY ITSELF (no gapps, magisk, etc) and see if you like it. If you do like it and want to add gapps then see FAQ 12.

Q3. What if my app, xyz, doesn't work?

A3. If your app doesn't work, then go back to your old rom.

Q4. Your rom is laggy and buggy.

A4. If you find the above, then go back to your old rom. There's only so much software can do on a 2015 budget level tablet. Remember a budget tablet will have the slower SoC/CPU and less DRAM than a top of the line model. Your tablet will also run slower when you use gapps. You can run a lot of software without using gapps. Research fdroid, newpipe, Aurora store etc.

Q5. What TWRP should I use?

A5. You MUST use TWRP 3.5.2_9. Get it from

https://dl.twrp.me/gt510wifi/

Q6. Why should I use this rom?

A6. If you don't like this rom, then don't use it.

Q7. Will you offer monthly updates with security patches?

A7. I will try to offer monthly security patches, but that all depends on if I continue to have high speed Internet in the future.

Q8. Can you help me? I'm a newbie. Can you provide step by step instructions?

A8. I don't have the time to help newbies, so please do your own research. There are lots of tutorials, videos, etc on how to flash roms. Newbie questions must be posted in the Questions and Answers forum, not here.

Q9. Can I report a bug with respect to the rom?

A9. Yes, but you need to supply the following information. If you don't, I won't look at it.

You must provide an adb logcat of the problem and tell me how to reproduce it. Note I will not be downloading any apps that require money or an userid/password. For example, if you have problems with Netflix, I cannot help you since I don't have a paid subscription. If you use some app that requires an userid/password, I cannot help you as I'm not willing to create another userid/password even if it's free.

To get a logcat, open up a terminal window.

# clear the logcat first
adb logcat -c
# start logcat trace
adb logcat > problem.txt
# reproduce problem
# wait until problem has occured, then stop trace by hitting ctrl-c
# attach the problem.txt ZIPPED as text files don't seem to get attached properly

Q10. Will you still build 18.1 for this device?

A10. Yes, for rest of 2022, but I will make a decision in January 2023 on how 18.1 and 19.1 will be maintained. If you like to help by building 18.1/19.1, please let me know.

Q11. Do I need to erase everything and format my data?

A11. Yes, you MUST erase all the partitions (system, data, dalvik/art cache, cache) using TWRP and MUST format your data before installing 19.1 when you are coming from stock or an earlier version of LineageOS or from another custom rom. If you get stuck at the boot animation for more than 5 minutes, it's likely because you didn't follow the instructions I just wrote. Dirty flashes from stock, other custom roms or older LineageOS versions are not supported and not likely to work.

Q12. What gapps should I use?

A12. I don't use gapps anymore. I use Aurora Store. As of Nov 6, 2021, I no longer make recommendations on which gapps to use as your mileage may vary.

Let me by crystal clear. YOU NEED TO DO YOUR OWN HOMEWORK selecting between the various gapps offered. There are 5: opengapps, nikgapps, mindthegapps, flamegapps and bitgapps. Each one will have it's own installation instructions. The only recommendation I will offer to use the SMALLEST version of gapps.

Don't be surprised that whatever gapps you use might have problems like "Just a sec", voice not working, updating google play store please wait, etc. These are NOT problems of the OS as the OS will run fine without gapps. These are gapps problems and you must ask in the gapps forum why it doesn't work.

In addition, some of the gapps may not install properly when using TWRP and say "cannot /mnt/system". For those cases, please use the LineageOS recovery.img you can download from

https://sourceforge.net/projects/retiredtab/files/SM-T550/LineageOS-recovery/

By flashing the LineageOS recovery.img, it will overwrite the existing TWRP and you will get a different UI.

Q13. I'm having problems with gapps, can you answer why it's not working?

A13. I WILL NOT answer any questions regarding gapps. This thread is about the rom, not gapps. Android does not depend on gapps in order to work.

Questions about gapps, for your courtesy, should be asked at

https://xdaforums.com/t/msm8916-whi...m-t35x-sm-t550-sm-t560nu-and-sm-p550.4479285/

Q14. Why isn't my post answered or ignored?

A14. Questions already answered in the FAQ will be completely ignored. Again, I do not use Windows OS or gapps.

Q16. What speed up/optimization tips do you suggest?

A16.

1. Turn off animations. Go into developer settings, scroll down to the drawing section, and set window, transition and animator scale all to "off".

2. If you don't have a google account, don't install gapps. Use Aurora Store to get your apps as you can get all the same apps from the play store using an anonymous login.

3. Dont' run more than 2 apps at the same time. You can probably listen to music in the background and use a web browser at the same time, but don't expect great performance from a 2015 entry level tablet.

4. Use a web browser like Brave that has built in adblock and privacy features.

5. Use newpipe to watch your streaming content. It has built in adblock so you don't have to watch forced ads.

6. Look for apps that are open source, ad free and lightweight.

7. Remove all unused quick setting "bubbles" from the quick pull down menu. I only need and have 6.

Q17. Does this rom support Magisk for root?

A17. I don't use Magisk myself so I don't know and Magisk is always being updated to fool Google's certification process. Others have reported Magisk as working, but I won't answer any questions regarding it.

Q18. Will this rom ever become official?

A18. With 19.1, legacy devices like ours will NEVER be official due to lack of ebpf support. See https://lineageos.org/Changelog-26/

Also, I don't want the responsibilities that come with being an official maintainer.

Q19. What is the difference between this rom and others?

A19. This rom tries to be pure LineageOS with little to no modifications.

Q20. Will there be any major 19.1 code modifications in the future?

A20. I don't anticipate any major modifications. There may be some small bug fixes and minor code cleanup, but all the hard work in getting the rom up and running and fixing all the major bugs have been done completed. This doesn't mean the code is perfect or well organized, but I won't be doing any major changes now that 19.1 is working.

Q21. Why did you fork the device and vendor trees for 19.1?

A21. The msm8916 repos seem geared towards phones and sometimes do not work or cause boot animation loops for tablets so I decided to fork their repos. In other words, what's deemed as msm8916-common code isn't common to all devices.

In addition, since I'm building SM-T350, SM-T357W, SM-T550, SM-P550 and SM-T560NU (all use the same msm8916 code), it seems easier to maintain all of them if I can control my own code repos and not worry if my changes affects the phones or not.

I have completely decommonized and rearranged the 19.1 msm8916-common tree so it's easier for me to maintain and build.

Q22. Can you build a variant of this device? For example, a LTE or S-pen version.

A22. If I don't physically have the device, I cannot and will not build it unless I can boot and test it myself. Even then, there's no guarantee that I can get those variant features working.

Q23. Can I load this rom on a variant devivce like LTE or S-pen version?

A23. The rom is built for the device explicitly listed. If you are an advanced user and understand TWRP, adb, odin, heimdall, you can try loading it on a LTE or S-pen variant by modifying the updater-script, but it may cause a bricked device, bootloops or non functionality of LTE/S-pen. You have been informed and warned!

Q24. What major code changes are in 19.1 vs 18.1.

A24.

- iptables has been removed in favour of ebpf

- keystore v1 has been replaced with keystore v2 which requires that the binder calls have some built-in security

- audio hal 2.0 has been deprecated

- legacy camera hal 1.0 and snap app have deprecated

Q25. I don't like the taskbar, how do I turn it off?

A25. Choose settings, type task into the search bar. Choose enable taskbar and disable taskbar. This will leave the on screen nav bar. If you want to disable that, go to settings, system, gestures, system navigation, gesture navigation.

Q26. Okay, I understand the consequences and that this is ALPHA rom and willing to take the risks outlined, now where can I find the rom?

A26. You can download it from https://sourceforge.net/projects/retiredtab/files/SM-T550/19.1/