[Samsung Galaxy Tab A series ROMs, Kernels, Recover] retiredtab:
FAQ - I spent hundreds of hours building this rom. 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/tree/lineage-18.1

The device tree files are at

https://github.com/retiredtab/android_device_samsung_gt58ltebmc

https://github.com/retiredtab/android_device_samsung_msm8916-common

https://github.com/retiredtab/device_samsung_gte-common

The vendor tree files are at

https://github.com/retiredtab/android_vendor_samsung_gt58wifi

https://github.com/retiredtab/vendor_samsung_msm8916-common

Q2. Is this BETA 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 early Jan 2022 with no major issues.

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

A3. I won't answer questions regarding why your app doesn't work. If your app, whatever it is, doesn't work, then go back to your old rom. It's difficult enough building and maintaining these roms. Remember, I'm an unpaid volunteer making a rom for free for your benefit.

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 (google apps). You can run a lot of software without using gapps. Research fdroid, newpipe, Aurora store etc.

Q5. What TWRP should I use? It doesn't matter if your device is a 355 or 357, you MUST use the TWRP below.

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

https://sourceforge.net/projects/retiredtab/files/SM-T357W/TWRP/

Q6. Why should I use this rom?

A6. You don't. If you don't like this rom, then don't use it. Yes, it's that simple.

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. 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. I do not run any Windows operating system so I cannot provide instructions.

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

Q10. Why doesn't MOBILE DATA/LTE/Voice/Phone calls work on this rom?

A10. Samsung abandoned this device on Android 5 and the binaries to make MOBILE DATA/LTE/Voice/Phone calls work are proprietary. I have tried to make those old binaries work and was not successful. I may be missing something or do not have enough experience to make it work so if you want to try, feel free to.

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 18.1 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. It's reported that opengapps does no testing on their daily builds and some version results in bootloops, bitgapps may run out of disk space will installing apps and Mindthegapps as causing overall slowdown of the system.

The only recommendation I can make is to use the SMALLEST version of gapps which is PICO or equivalent naming convention. DO NOT use anything other than PICO. That is, do not use nano, mini, stock, etc.

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 and I don't use gapps so I cannot help you. Android does not depend on gapps in order to work.

Q14. Why isn't my post answered?

A14. It's probably because it's answered in the FAQ or not relevant to the rom. Again, I do not run Windows OS or use gapps. Questions already answered in the FAQ will be completely ignored.

Q15. Can I turn off the on screen navigation keys?

A15. To turn off on screen navigation, go to settings, system, advanced, gestures, system navigation, gesture navigation. It's enabled by default because I find it useful. If you don't like it, you only need to disable once and your preference will be remembered. If you want to invert the onscreen keys, goto settings, system, buttons and enable invert layout

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.

Q17. Does this rom support Magisk for root purposes?

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. Never. I don't want the responsibilities that come with being an official maintainer. In addition, I know my device trees, code organization and git commits will NOT meet LineageOS standards. Remember, I'm an unpaid volunteer doing this in my free time and sharing my work with you for free so you can get hundreds of hours of enjoyment from this tablet.

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

A19. This rom tries to be pure LineageOS with little to no modifications. Other roms may have different UI, different bundled apps, etc. Use whatever meets your requirements.

Q20. Will there be any major 18.1 code modifications in the future?

A20. I don't anticipate any major modifications. There may be some slight tweaking to the sepolicy, 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 18.1 is working. Any major changes will be done in 19.0.

Q21. Why did you fork the device and vendor trees for 18.1?

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-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 still have not figured out the best way to manage all my repos and it's a work in progress.

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. Will this run on the SM-T355 or SM-P355?

A24. I do NOT have a SM-T355, but one user reports that it loads and runs on a SM-T355Y. See post #18.

Q25. Will this run on a SM-T357T variant?

A25. Yes, one user reported that it boots on a SM-T357T. See post #5.

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

A26. Downloads are at

https://sourceforge.net/projects/retiredtab/files/SM-T357W/