yashsingh1/xdaforums huggingface dataset:
[Android General] comfortable:
Yep showing up fine here.
[Android General] comfortable:
I will try this later tonight since I am fairly certain I didn't have it running in the background. I did reboot just to make sure all drivers were 'ready' but didn't try that yet.
[Android General] Viva La Android R.I.P.:
If that doesn't work, I can give you the steps to updating your device and fastboot drivers manually using the Windows Device Manager menu. In fact I'll list those now.

• Connect your device to your PC or laptop with a micro USB to USB data sync cable. Ensure your tablet is in fastboot mode;

• Right click on the Windows Start button and select Device Manager,;

• Look through the list of devices to find your tablet. It may be listed simply as "Android Device" but you'll know it when you see it. It will likely be under the heading of Portable Devices or Other Devices. There will likely be a yellow exclamation mark accompanying your tablet, indicating a driver issue;

• Right click on your tablet in Device Manager and select "Update Driver";

• Now select the option for Browse my computer for driver software, followed by the option at the bottom of the menu for Let me pick from a list...;

• At the top of the list you will see an option for "Android Phone." Select it. Next you'll see a list of OEMs. Choosing the exact manufacturer isn't significantly important here, as many device drivers are either generic or universal. Choose Google if available, or Motorola. Or, of course, Lenovo if it happens to be on the be list;

• On this next list you will see some various driver options. Select the driver titled "Bootloader Interface";

• Follow the prompts and allow installation of the driver. Now go back to your fastboot command window and execute:

fastboot devices

An alphanumeric string will display in the command window if you are now properly connected. If not, reboot your PC and try again.

By the way, which version of Fastboot are you using? The reason I'm asking is, I've had a good overall experience with the Minimal ADB & Fastboot v1.4.3 utility on the Tab3 8. Have you ever used it?
[Android General] comfortable:
That did it. Thanks so much. I was using the adb and fastboot files you provided but this computer has been used to flash several devices now, so some weird driver stuff was bound to happen sooner or later (hah). I installed your twrp recovery image (first through command and then again while in twrp itself as someone had suggested earlier in this thread). This was necessary for it to 'stick'. I could not (and still cannot) access twrp with any VOLUME / POWER button combination I tried (my timing could be off because I did get some chinese (presumably diagnostics and testing) thing show up once or twice but mostly did many attempts resulting in static Lenovo logos. Getting into twrp was only possible for me via command adb reboot recovery.

Rooted with magisk. Thank goodness :) Now working on why I cannot install apk files from an attached USB stick (there was a problem parsing the package) but if I copy the same files to the Downloads folder on my internal storage on the 850f they install fine. I'm not sure what is going on there. I tried several file managers.

Anyway, thanks heaps for the help!
[Android General] Viva La Android R.I.P.:
Indeed. Glad I could help. On using hardware buttons to boot into recovery mode, it is a tedious task. With the tablet powered off, hold the power button and then, a split second after hold volume up + volume down as well. Now the trick is, to let go of the power button before you feel the tablet vibrate, and continue to hold both volume buttons until you see the TWRP splash screen.

It's a timing thing. That is odd on the APK packages. You get a parse error when attenpting to install apps directly from USB storage but, when the same app package is copied onto your device in the Download directory, installation works fine. Is that accurate? First thing that crosses my mind is the filesystem standard that was used to format your USB storage, i.e. ext3, FAT32, exFAT, f2fs, etc. I'm wondering if your USB was formatted using a standard not natively supported by Android. That runs into limited use and bizarre problems like parse errors and system deadlock.
[Android General] comfortable:
USB storage should be fat32. I need to get some f-droid app to verify because I am away from the computer. I have this niggling feeling I may have messed something up. Maybe with Magisk (?), because I have used the usb fine on several devices without first having to copy over the APKs. Anyway more reason to install an unofficial LineageOS soon, if it is stable enough for everyday use.

I will try getting into recovery using only my fingers (and minimal cursing) again tonight. Thanks for the tips!
[Android General] Viva La Android R.I.P.:
If you have not yet tried it, use the MiXplorer file manager app. It's open source, ad-free, fully customizable, and free of charge.

[APP][2.2+] MiXplorer v6.x Released (fully-featured file manager)

[APP][2.2+] MiXplorer (full-featured file manager) Hello everyone! My name is Hootan. I work on XDA in my free time and this file explorer is my favorite Android project! MiXplorer mix of explorers (SD, FTP, Lan, Cloud and other storage...

xdaforums.com

Once you install it, open the app and grant the usual permissions, then tap the three-dot menu in the upper right of the interface. Select Settings, then More Settings, and scroll down until you see an option titled Enable OTG. Select it. This installs custom OTG drivers on your device and establishes communication with your OTG storage device. This has worked for me on several devices where USB OTG support was being buggy. MiXplorer also has root support, so I'd encourage you to try it. It is the only file manager I use now.
[Android General] pndwal:
Just playing catch-up; Sadened to learn this.

I'd searched for him after original dummy-spitting / thread sanitised incident. (He'd already said he wouldn't be back / asked me to take over threads etc.) Discovered some of his history in school of hard knocks, comments on life inside etc, but never caught up again. Had some very interesting discussions / learned alot... Short fuse, but extremely helpful individual. Actually missed his presence for some time now...

Yup: see below

Here's some posts that may be useful I thought I'd colate due to new interest here. Hope it helps:

OP goes AWOL:

https://xdaforums.com/t/guide-bootloader-twrp-root-lenovo-tab3-8-tb3-850f.3559786/post-77905109

My useful notes / links:

https://xdaforums.com/t/guide-bootloader-twrp-root-lenovo-tab3-8-tb3-850f.3559786/post-78831923

@limited_imagination's notes / link to ZIP archive with all OP's initial post files. (he said "my Google drive is getting quite full, and I need to flush it soon. So grab it while you can, all), but looks like it's still available!:

https://xdaforums.com/t/guide-bootloader-twrp-root-lenovo-tab3-8-tb3-850f.3559786/post-79233049

Stock: For some working ROM links, see posts #552, 594, 596, 600 here.

Latest stable LOS14.1, credits, other Tb3 850f threads listed here:

https://xdaforums.com/t/guide-bootloader-twrp-root-lenovo-tab3-8-tb3-850f.3559786/post-78829321

All best, 🤠 PW
[Android General] Viva La Android R.I.P.:
That's good stuff. Thanks for sharing @pndwal. Yeah I knew he was at XDA for a good while but I never knew why he had left. I recall him saying something about it, but just can't recall now. He and I used to argue like two siblings. Yeah, short fuse certainly. The worse his health got, the shorter the fuse. He was still trying to work and travel like he did 20 years ago. With cancer and health declining that didn't last long. The night before he passed, I got a call from his brother, who left a voicemail and basically told me the inevitable was quickly approaching. By the time I knew I had a voice mail the next day, the ghost had been surrendered.

That a$$hole one time talked me into climbing a 210 ft cell tower in the pouring rain (no doubt because he didn't want to climb it himself). I am not even a certified climber. I work base stations, substations, nodes, switches and things on the good old ground. And I am talking about apocalyptic torrents of rain that even old Noah himself would have cringed upon seeing. But I made it or I wouldn't be typing now.

He sure knew networking and signal analytics, and what be lacked in good interpersonal skills, he made up for in his ability to troubleshoot wireless networks.

Again thank you for sharing. ☮️

By the way, the LOS 16 Go Edition ROM I have been seeking for the 850F (AKA The Lost ROM) I am pretty certain MotoJunkie01 would have had a copy of it. He was one of the creators of the Telegram group where it originated, and may have even had involvement in potting it. I've asked everybody I can think of who knew him. But, like I said previously, it would be far simpler to port it from scratch. Our present 850F kernel, Linux 3.18.19, is compatible with Android versions 6.0 thru 10. So it would have no issues booting an Android 9 Pie based custom ROM.
[Android General] comfortable:
Hi guys. Some nice background info there.

Trying LineageOS

Pndwal, I tried the 850M lineageos very briefly ( with 850f mod boot) but quickly went back to my backup. This may sound stupid but I hated the responsiveness and the No SIM message plus the model showing as 850m.

Restore weirdness

Speaking of backup, I tried to restore a twrp backup I made (right after installing twrp) but couldn't. The issue? Despite my system partition being large, it would have that partition done in 0 seconds or 2 seconds. I have no idea why it would essentially 'skip' it. I saved all partitions when making the backup, but only restored 3 of the main ones when restoring, because I was told a while ago to only restore what you need. After the restore, when attempting to reboot twrp, I'd get a message that no OS is installed and if I was sure I wanted to restart. What's weird is I made yet another TWRP backup after I set up the device more to my liking and that restored fine. The second backup I made just included 3 partitions. No superfast 'restore' of the System partition that time. Any ideas?.

Back to root

I am basically back to the rooted device with stock OS and about 40+ Google and Lenovo undesirables disabled using De-Bloater. When using Mixplorer to access APKs directly from the USB OTG stick I am greeted with the following

Using Total Commander (one of my few closed-source favourites) results in:

Using the native android settings file browser:

Copying the apk files from the usb to the device is necessary for some reason. Mp4 files play from the same stick fine. On the bright side, I am happy to report that I can access TWRP with just my fingers fairly successfully now. Thanks for the tips!
[Android General] Crisdax:
try recuperate with qfile
[Android General] comfortable:
Hi Crisdax. That problem was solved. It was the driver install. The only problem now is installing apk files from usb directly doesn't seem to work as it does on other devices using the same stick. Not sure why I have to copy them over before installing.

Anyway, thanks all for the help.
[Android General] Viva La Android R.I.P.:
Gents and Ladies, I just wanted to check in and say hello. I am making decent headway on revamping the LOS 14.1 ROM. While I will release a full changelog when finished, these are a few of the alterations I've made so far.

• Removed all RIL, telephony, SIM and cellular network related settings from SettingsUI.apk and SettingsProvider.apk, I e., changed Settings interface to reflect WiFi-Only tablet device.

• Increased haptic response and touch sensitivity on the touchscreen digitizer via build.prop/default.prop.

• Android security patches up to December 5, 2020 (actively working towards bringing the patch level all the way up to date).

• Updated all common libraries, dependencies and modules via Maven Central & remote repositories.

• Converted specific app modules to library modules.

• Added optional AMOLED black theme (dark mode) system-wide.

• Updated system components, system apps, services and framework to the most current LineageOS 14.1 source.

• Updated MediaTek WiFi and Bluetooth drivers to more current versions.

• Numerous bug fixes and stability improvements.

I'll wrap it up in a couple of days I think.
[Android General] Viva La Android R.I.P.:
Out of curiosity, did you get APK installation to work directly from USB OTG storage.
[Android General] comfortable:
Hi mate. Not solved yet. It's not a huge problen but it's one of those things that has me wondering why. I am so excited to try the Lineage you are teasing us with above. Sounds fantastic!
[Android General] Viva La Android R.I.P.:
Coo. Yeah I'm wrapping things up on the LineageOS 14.1 ROM. I ran into some buggy behavior on the system-wide dark mode feature I added, so I've undone all of that and resorted to good old-fashioned deodexing and per app theming with an overlay manager. This way is much nicer in terms of UI aesthetics, and won't cause stability issues like my previous implementation. While LOS 14.1 does natively support USB OTG protocol, I am adding custom OTG drivers for
[Android General] Viva La Android R.I.P.:
I'm wrapping things up on the LineageOS 14.1 build. Had to resort to another tactic on my added dark mode feature, but it'll be better in the long run. While LOS 14.1 does natively support USB OTG protocol, I have added custom OTG drivers for added filesystem support; exFAT (R/W), FAT32 (R/W) and NTFS (R). This effectively forces recognition and accessibility on OTG storage devices which have been formatted and configured on a Windows PC, for example, and would not normally be supported by Android's native OTG implementation.
[Android General] Viva La Android R.I.P.:
I am having some major difficulties with the XDA app as well as the XDA web-based user interface. I either cannot get my posts to add to the thread, or they will be duplicated and post multiple times. I have the app on 8 different devices and the result is always the same. When creating posts or threads, the cursor freezes and sticks, resulting in a huge effort to type even a single word. I made a post here earlier today -- which I do not see now -- that was a small paragraph, but took me nearly one hour to complete. I'm typically very calm and sedate, but my patience gets quickly unravelled on this XDA issue. Reaching my boiling point, I took my Tab3 8 and pummelled the floor with it until the logic board actually came through what was left of the digitizer assembly. While this was very therapeutic for my built up stress with this app, it does create a bit of a holdup on my LOS 14.1 project, which I was actually wrapping up. I am going to order another device and see what I can figure out about getting the XDA app to work. I may also need to get another device just for it. I'm on the web-based interface now and it's not much better. I will keep my progress posted. Thanks guys for your support.
[Android General] comfortable:
Sorry to hear about the tablet!

I know the feeling. I have had a fair share of editing text frustrations on xda (I haven't tried the app yet). Please just take your time if you decide to get a new device to finish things off. No dramas if you decide not to.

Sidenote:

One of my best experiences has been with LineageOS on the samsung galaxy s5 due to the support for other filesystems (which you spoke about earlier). I guess LineageOS dropped support due to licensing?
[Android General] Viva La Android R.I.P.:
I needed a new device anyway. I have a refurbished 850f en route. The one I got a few months back was used and had considerable wear. The volume rocker was in the mid stages of giving out as well. On filesystem standards and licensing, the subject matter gets rather complex. Keep in mind that, while Android has long supported USB OTG, it has never officially supported NTFS or exFAT. Still to this day, the NTFS filesystem is not supported by AOSP., while exFAT is supported only on some newer devices. Certain device manufacturers, such as Samsung, have added such support via their custom Android overlays like Samsung Experience and One UI. Huawei done the same thing with EMUI and more recently with HarmonyOS 2.0. Samsung was also known to add native support by way of firmware implementations on some devices.

The legal waters on this topic are extremely muddy. It appears that some companies and corporate entities interpret the licensing and fair use guidelines differently, resulting in a vast disparity regarding native support of these filesystems. Some companies will, while others won't entertain the notion. Many Android file explorer apps now include native support for these filesystem standards. MiXplorer is a good example, as well as a file explorer by Paragon Software.
[Android General] comfortable:
Oh :)

I have noticed this whenever I have tried to download a linux iso of 4GB+ on storage using fat32

Good info. In my opinion better file system support is one of those critical things that's just never talked about. Thanks for your work.
[Android General] Viva La Android R.I.P.:
My Tab 3 8 is due to be delivered this Friday. I could have probably finished up without having a device, but I have building blind. Testing is crucial to me.

Out of curiosity, which variant of the 850F do you have? The 80 or 81 HW variant? On the back of your device will be a manufacturer's sticker with your serial number printed on it. At the end of the serial number, you will see either an 80 or 81 within parentheses...(80) or (81).
[Android General] comfortable:
Good policy. Take all the time you need to test.

My 850F is the 80 variant.
[Android General] Viva La Android R.I.P.:
Mine too. I've only ran across maybe 3 people that own the 850f (81) variant. It seems much less common.
[Android General] comfortable:
Did they improve anything?
[Android General] Viva La Android R.I.P.:
Seems to be an insignificant difference in board platforms. The (80) variant has the MediaTek mt6735m SoC, while the (81) variant has the MediaTek mt8161p. The kernels on both variants, however, are compiled for the mt6735m. The two platforms are virtually identical in terms of specs.

I got my new 850F yesterday, so I'm back at it again.
[Android General] limited_imagination:
I haven't visited this thread in a long time, having moved on to a Mi Pad 4 to replace my TB3-850F.

But it's really cool to see you pick up the baton on this.

You now know four people with an (81) variant... add me to the list.

Mine has a manufacturing date of 2017-04-10 on the sticker.

I look forward to testing your new build!
[Android General] Viva La Android R.I.P.:
Thank you for your words of encouragement. I've found out that, not only are there two hardware variants to the 850F, but there are also some regional variants as well. Lenovo and Motorola have long been known to push the envelope on device variants, a tactic that has greatly broadened their global marketing of mobile devices. I am currently making bids on a 850M on eBay. If I can snatch it up at a decent price, I'm curious to see the difference between the two Tab3 8 models (other than the 850M's GSM support).

Anyway, thanks to you, @limited_imagination, @pndwal, @comfortable, and all you guys who made me feel invited here. This is the true spirit of the custom Android community. I see no roadblocks in the way for having my LOS 14.1 build posted by this weekend. I have heard from the original OP of the existing LOS 14.1 thread. He has given his blessings for my contributions as well as permission to take over his original thread. I am getting with a moderator to try and make that happen.
[Android General] yurais:
the google drive link is not working... could someone upload this to androidfilehost ?
[Android General] Viva La Android R.I.P.:
Great news gents (and ladies, if present), I will be posting a build later tonight.
[Android General] comfortable:
No rush here. Please take your time. If you feel it's too much work, that's fine too.
[Android General] Viva La Android R.I.P.:
Greetings. Okay I seem to have broken my first rule of thumb when staring on this project: NEVER ASSUME ANYTHING. So I assumed that the LOS 14.1 ROM was integrated with a LOS boot image. Had I read the threads a little more thoroughly, I could have saved myself a ton of trouble. As you guys probably already knew, this is a dirty port hybrid boot image, with a LOS ramdisk and a stock Lenovo kernel. My trouble with SELinux enforcing, merged changes and force closing crashes have now come to light. (I do have to assume that either (1) Lenovo never released the kernel source code for the Tab3 8, or (2) nobody has sat down and actually compiled a kernel from source.) I had to go back to the drawing board on a large sum of my work. I just wanted to give an update and apologize for my huge oversight. Now that I have a full perspective of everything, I feel confident that things will go a little smoother. Plus, this will give me a base template for porting other custom builds. Our present kernel, 3.18.19, supports Android 6.0 all the way up to Android 10.

Anyway I'm elbows deep once again. Wish me luck....
[Android General] comfortable:
When do we receive our refunds? :)
[Android General] limited_imagination:
Hi again Viva. Just checking back on this thread to see how you are doing.

I expect you already found a copy of the source code for this device that Lenovo posts here: https://pcsupport.lenovo.com/cr/en/products/tablets/a-series/tab3-8/downloads/ds112711

You may have noticed that much earlier in this thread, I was trying to get that code to build a kernel alone, not as part of an LOS rom. I was never successful, despite much mangling of the official source code in an attempt to remove or alter code that caused errors that borked the build process. IIRC, somewhere back in the mists of this thread, I actually mangled it enough to complete a kernel build, but flashing that kernel to the device soft bricked it.

Subsequently I have learned a bunch more about the build process, and was able to successfully build LOS for my Mi Pad 4: https://xdaforums.com/t/rom-beta-10...ad4-mipad4-plus.3989187/page-52#post-85504115

In all the trial & error for the Mi Pad 4 LOS, I discovered that a lot of build errors were created by incorrect configurations of my Linux VM, and the final piece of the puzzle was to install and enable ZRAM. When I ran the build after that, it got to the end, although still throwing a few error messages and warnings along the way.

All this to say, maybe if I had configured my Linux VM better when I was playing with the kernel source code for the TB3-850F, then maybe it would have built correctly while still throwing a few error messages along the way.

If there is anything I can do to help, shoot me a PM, and I'll see what I can do. I still am pretty inexperienced, but having got a successful LOS 17.1 build to compile and then flashing it successfully to my Mi Pad 4, I am at least a "build bot" status now. :)
[Android General] Viva La Android R.I.P.:
Great to hear from you. And congratulations on your Mi Pad 4 build of LOS 17.1. So it sounds as though you compiled the entire ROM from source. Impressive. Yeah the source code released by Lenovo for the TB3-850F seems to include a proprietary OS bundle in addition to kernel source. Doesn't look like the typical kernel source code archive, but maybe I'm looking at itt wrong. My difficulties on smoothing this ROM out mainly involve the fact that this build was dirty ported twice before I began work on it. I encountered a lot of unforeseen obstacles. I fixed some bugs, included some vendor overlays for dark mode, updated libs and databases, etc., only to have the entire ROM crash when I put things back together. On a positive note, I have assembled pretty well the entire framework needed to port additional custom ROMs in the future. But yes, I will surely PM you and pique your brain on a couple of topics very soon.I haven't had much free time lately either, so that's been a bummer on this project. Anyway thank you sincerely for your offer of assistance and your encouragement. I shall be in touch.