yashsingh1/xdaforums huggingface dataset:
[Android General] wezroot2k:
Sorry guys my bad didn't mention that

but i actually flash the TB3-850m lineage 14.1 rom on my Tab3-850f device just today as mentioned above have been using it since rooted with magisk but the only problem i have is when you reboot or shut down the device it keeps restarting and eventually about ten minute or more it finally boot to the OS.
[Android General] pndwal:
Well done installing on 850F! - did you need to edit xml file and repack the ROM to avoid TWRP errors? Any other tricks used?

Re his 850F port to LOS 14.1, in post #240 (page 24)[MENTION=7383447]MotoJunkie01[/MENTION] said:

"... after months and months, trials and tribulations, etc, etc, Nougat is imminent for our beloved 850F. Good Lord you wouldn't think a port would be that difficult coming over from the 850M. But I swear, I think I could have ported from pure source with less difficulties. Again, though, all focus has been in the kernel and hardware blobs. We are nearly stable my friend." Of course, he never published this ROM, but it could be that lack of updated commits for kernel and differing hardware blobs are causing problems.

Also, some have had such instability / restart problems on other devices using Magisk for root, so could try other SU solution, SuperSU etc. PW.
[Android General] wezroot2k:
well no tricks or editing xml or repacking rom i got the rom has is, copy to my external MC enter TWRP did all the wipe functions and then flash the rom (433MB) zip file no errors so basically i flash a fresh rom and reboot thats when i notice restart bug so left it for a time it boot to OS and i did not flash Magisks until i booted to the OS so maybe i can say Magisks is not a fault. But looking back i am wondering if i had made a mistake while Flashing because the Flashing tutorial for this said i should put on the internal i put it on the external so that is a thought and maybe i should just flash it over the stock rom again somthing to think about.

The quote from MOTOJUNKIE is rather insightful i myself have bookmark some His tread just hoping that one day he will return still hoping:good::good::good::good:

---------- Post added at 09:23 AM ---------- Previous post was at 09:15 AM ----------

ok guys I willing to use my Tab3-850f has a guinea pig so to speak, that is i going to flash a stock rom with lock bootloader etc unlock the bootloader and try flashing the rom from internal storage without in wiping and see what happens ok so give so time and i will update you guys what results are okay:good:

PS: THE camera works though no problems.;)
[Android General] pndwal:
Surprising flashed so easily. Again, well done!

You probably have as many or more clues than I do on this. Looking forward to hearing re your results. I'll help if I can. (Are all camera functions working fine???) Regards, PW
[Android General] wezroot2k:
yes all features that comes the lineage OS camera back and front cameras video recording bank and front cameras.
[Android General] pndwal:
Great news. Funny [MENTION=7383447]MotoJunkie01[/MENTION] said:

Thanks, PW
[Android General] wezroot2k:
well Motojunkie01 may have been talking about is port of lineage 14.1 and been doing some sort of test

but as stated above i no problems when i flashed the 850m version

PS just doing some OTA updates currently and then i will unlock the boot loader install twrp and then root with Super SU and then proceed to re-flash the Lineage 14.1 custom rom.

So I will make you guys know how goes:good:
[Android General] pndwal:
Thanks.

Strongly suggest you do full nandroid backup from TWRP, and save it to pc, before reflashing custom ROM, if you haven't done so already. I posted on import of doing backup here, page 26, second post. PW
[Android General] wezroot2k:
ok did what you said did the backup and save to pc then did flash but this time i did no wiping and i got and error something about updater error and that i must try a fractory reset did the fractory reset and it installed no errors

then i flashed super su no errors flash gapps no errors also, but while flashing super su it warned at the end of the flash that the device will take sometime to boot and that will loop sometime, all the loops is going on now the device is keeps rebooting, so when and if its boots to OS i will post it right away ok.
[Android General] wezroot2k:
ok people so here's the deal with this lineage 14.1 rom ok so flashed the rom and let it boot to OS so after an extend amount of time i got impatient and did a wipe of dalvik cache and cache and lo and behold it boot straight to OS

so let me tell you a bit about the OS the gapps that i flash came a pixel launcher installed so right off the bat you can choose that launcher, camera works fine, know have cast function own built in file manager, and because its a port of mobile phone the usual phone dialer sms message which can be disabled with the icon removed from the app drawer, WiFi works no problems. So the OS comes with an extended power menu that can be activated in developer option were extra functions can be found in the power menu and with that i had to go test what will happen if reboot the device and thats where i am currently at looking a lineage boot screen and watching the device keep looping. So when it boots to os i can give more details but for know we here should try find a solution to mini boot loop problem.So any devs out with any idea or solution can come forward and let squash this bug.:good:

i wiil keep u guys posted.
[Android General] pndwal:
Thanks for efforts.

Have you tried without gapps? (I'm guessing no Google services come embedded in ROM.)

When it boots, is it stable as long as you don't reboot? PW
[Android General] wezroot2k:
yes sir quite stable as long as you don't reboot, also the first time i flash this rom i did a soft reboot and it did not loop at all.
[Android General] pndwal:
Have you tried without gapps? (I'm guessing no Google services come embedded in ROM.) PW
[Android General] pndwal:
Did it come back from bootloop? Any more testing? PW
[Android General] wezroot2k:
OK people sorry for the late reply but the weekend was a little busy for me so I couldn't spend much time on testing the new OS but i did do a little comparing the stock build prop values that PW posted and the build prop of the linage 14.1 port and what i found out well first of all the Rom seems very strip down i think the actual size of the flash zip is 432MB to be exact, so build prop for the Stock Rom has far more values in comparison to Lineage port which seems to me to have at face value to also have values that were missing. So I am going to study the build props some more and do some testing and see what can happen but i would like some advise on maybe what can be tweaked because i have never really played around with build prop values before and also i am also considering seriously to port this ROM for the device so a little help would go a far way there.

Presently i did a fresh install and just rooted with SuperSu so you know whats going happen with loops so as soon as the device boots to the OS i will do more build props testing and start to prepare myself for LINEAGE 14.1 PORT PROJECT:good:

PS. Still Stable apart fro the boot loops everything works so far.
[Android General] pndwal:
Sounds good.

The Russian 4PDA site has much info on bugs extant for LOS14.1 on TB3-850M here: http://4pda.ru/forum/index.php?showtopic=764969

Firmware post #697.

Surprisingly and interestingly, al_rus mentions here that kernel and comms in this port are from 36th firmware (ie TB3-850M_S100036_171222_ROW marshmallow stock). [Kernels from later versions of android generally work with earlier, and it seems sufficiently up to date kernels from earlier versions can work with later]

Also, a couple of other Russian users have flashed this on 850F - 88FLY88 (post #824, said "became normal after about 10 reboots") and Cooper 4404 (post #854, said used but couldn't stabilise after reboot so returned to stock).

al_rus advised 88FLY88 regards loops: "Well, you have another model. In theory, at least the kernel needs to be replaced with yours, it may be better to work." (post #855) - no one appears to have done this however.

And he posted link to 4PDA topic "Porting firmware for smartphones based on Mediatek 6735/53 processors" - http://4pda.ru/forum/index.php?showtopic=715583 (post#859) - may be useful for you.

I'm concluding then, that simply substituting TB3-850M_S100036_171222_ROW marshmallow stock kernel for latest 850F stock kernel (ie TB3-850F_S100031_171010_ROW marshmallow stock) should produce a stable, bootable ROM for us. Guess you may need to re include our build.prop and make other adjustments, but correct kernel will be a good start. - Let me know what you think. [This way, porting may not be the big deal it was for [MENTION=7383447]MotoJunkie01[/MENTION]]

I'd try all this myself, but very strapped for time presently.

Regards, PW.
[Android General] wezroot2k:
hi everyone OK firstly how would i port the kernel from the 850F to 850M? if that what it takes i would do that right away.

OK this what i for this port is generally get rid of all the telephony and sim card options and try to stabilize the boot process. I also bin looking at the flash zip and it has the system folder and the build prop file, so do anyone think edit the system folder and build prop from the flash would achieve a stable port, and by edit i mean deleting the telephony and sim options and maybe importing some values from the stock Firmware of the 850F

Again my device can be the guinea pig here for testing.

---------- Post added at 08:02 PM ---------- Previous post was at 07:14 PM ----------

hey PW

where can i get stock version rom zip file for the 850F

motojunkie file are locked can't get access.
[Android General] pndwal:
boot.img contains the kernel and ramdisk, critical files necessary to load the device before the filesystem can be mounted. Just extract boot.img from stock ROM, and flash it over ported LOS to fix stability (theoretically). Replace in LOS package if it works.

Nb you will lose root as boot.img is modified by SU. (That's why you can simply flash unmodified boot.img to unroot or cleanup root when root manager fails to do this.)

A thread regarding boot.img structure / editing: https://xdaforums.com/showthread.php?t=443994

[MENTION=6939319]Hemphiz[/MENTION] found a working link to 850F ROM. (Twrp-flashable-TB3-850F_S100031_171010_ROW.zip). His post in page 35 this thread. https://drive.google.com/file/d/1f271tqJXL3d2thSnDa-lcNlrwMwDZxQy/view?usp=drivesdk Please give him kudos.

Here is latest full official ROM link for TB3-850F:

http://lenovo-forums.ru/files/file/1549-lenovo-tab3-a8-tb3-850f_s100030_161209_row/

This link is found in 4PDA thread for TB3-850M firmware: http://4pda.ru/forum/index.php?showtopic=764969 (This includes 850F info).

This will update via OTA (Settings, About tablet, System updates) to tb3-850f_s100031_171010_row. (Can't get OTAs without stock recovery.)

About This File

Lenovo Tab3 A8F - firmware TB3-850F_S100030_161209_ROW

Creator: Lenovo

Build Date: 09/12/16

Firmware type: Firmware for PC

File size: 1.14 GB

Archive password: lenovo-forums.ru

OS: 6.0

Description:

android 6.0

AOSP

Kid mode

ONLY WLAN!

Firmware for the Euro-region (including Russia and Ukraine)

Several have flashed this to recover from boot-loop successfully.

Archive password: lenovo-forums.ru

These files come with the drivers and spft needed.

Seems they also re-lock the bootloader.

Important: Many have encountered problems with the Vcom driver connection:

You will probably need to hold the volume down button and plug the usb cable in at the same time while spft is in download mode. This worked for others. (Thanks to [MENTION=5003632]stonedpsycho[/MENTION] for this trick.)

See posts #66, 69 & 71 in [MENTION=5273366]Lister Of Smeg[/MENTION]'s thread: https://xdaforums.com/android/help/lenovo-tab3-8-2016-custom-recovery-t3483454 for my instructions, working alternative links, and Russian site links including login method if you want to get any files hosted on 4pda.ru. (Links to locally hosted files will appear dead unless logged in).

Regards, PW.
[Android General] wezroot2k:
HELLO EVERYONE GOOD GOOD NEWS

But first i want to say a BIG BIG THANK YOU TO PW for his tremendous help and advise on how to stabilize the port of lineage OS on our beloved TB3-850f device again a big THANK to PW.

Okay so people the good news is that i stabilize the ROM in terms of the boot-loops after power off or restarting the device so now there are no loops and constant restarting of the device when you power off or do a full reboot:D:D:good::good: great isn't it.

but i only upon advise from PW just extract the boot.img from both roms and then transfer the kernel and ram-disk from the stock ROM to the ported ROM boot.img then copy the modified port boot.img to my external SD card and flash through twrp and worked flawless no itch or freeze it just booted to OS and i have tested the reboot from OS three times straight and no loops:D on the third boot it seem to load even faster so it fair to say the rom has been stabilized:laugh::good:

so only thing left to do is to replace it in lineage 14.1 flash zip and flash to the device, 1st i gonna to do a dirty flash with no wiping and then do a brand new flash wiping every partition so i will let you people know what happens on both counts OK wish me luck

thanks again PW
[Android General] pndwal:
Thanks for kudos (you could try hitting the thumbs up [thanks] button :) ), n great to hear results.

When I caught up on 4PDA thread, I had a hunch Motorjunkie was only working on that kernel as he thought it was from device the port was from, but actually stock TB3-850M kernel was used. So simply by substituting kernel and ramdisk in boot.img with stock 850F kernel and ramdisk, we have the equivalent LOS 14.1 for 850F, stable and with next to no effort.

This means TB3-850F users can simply flash LOS for 850M, and then modified Boot.img to achieve stable LOS installation.

Did you try booting / functionality with stock build.prop? May still need to merge entries from 850F stock build.prop with one from LOS.

Hope you don't mean that literally - NEVER wipe every partition! [Thankfully, TWRP won't allow you to do this anyway].

There are many partitions on Android devices, many very critical, and vulnerable when any sort of modding is done. For this reason, make sure you have a full nandroid backup done in TWRP :) Info I previously posted on this - post references in this thread:

Moral: don't risk any modding without full nandroid backup.

Many thanks for your efforts with this. PW.
[Android General] wezroot2k:
GM People.

well good news again i did the two re-flash with the LOS modified rom zip which included a modified boot.img as stated above 1st doing a dirty flash without any wiping and then doing another flash after doing a full wipe which include doing a Factory reset from twrp and then an advance which include wiping dalvik cache, cache, data system and internal SD and flashing the modified LOS flash zip with modified boot.img and it worked flawless no loops, booted to OS did my 3 reboot test and there was no loops, so i can safely say the ROM is stable so far:good:

So thanks to PW again for is tremendous help and keen advise. But PW i want to modify the ROM a bit more and make it a true Port of LOS for the tab3 850f so the question is

Can i use the build prop editor to change some values like getting rid of the telephony and sim card stuff and making the port a true 850f tablet OS as should be, and if so what values would you advise to get rid of or modify.

i know maybe i can change the name from 850m to 850f but i want to get rid of telephony and sim card options from the setting and device overall.

PS: on a side note this LOS comes with its own SU addon which when accessed by any root app will show the hashtag symbol on the notification bar which i think is a nice feature:)
[Android General] pndwal:
Did you modify boot.img, or use 850F one as substitute?

Sure you can. But did you try booting / functionality with stock 850F build.prop to see if it works with LOS, or creates problems?

If it works (boots), I'd be inclined to use / edit this one. If not, use / edit the one from LOS.

Editing should be a matter of comparing entries between stock 850F and 850M built props to see differences. Eg entries re telephony (and other functions) common to both LOS and 850M prop, but not in 850F prop file would be modified, but entries common to both 850F and 850M prop could remain in LOS prop.

For other entries, I'd keep / add any from 850F prop that don't cause conflicts: compare the three props, use common sense, and test by rebooting frequently so if ROM fails to boot or exhibits problems you will know what set of changes caused it and can reverse these.

Hope it helps, PW
[Android General] wezroot2k:
At first i used the one from the 850F but it failed, keep rebooting to recovery. then i extracted the boot.img from both the LOS 850m port and Stock 850f using MTK_ Extractor and replace the kernel and ram-disk of the LOS 850m with the stock 850F kernel and ram-disk then flash the modified boot.img with twrp and it worked flawless no loops what so ever, even after three reboots

thanks

---------- Post added at 05:10 PM ---------- Previous post was at 04:50 PM ----------

By the above quote do you mean or suggesting that i simply copy the build prop from the stock 850f to LOS 850m rom.
[Android General] pndwal:
Just to test if LOS will boot with it, yes, but my experience streamlining build.prop is very limited, and you may need to edit some entries.

Here's an XDA guide you may find useful, with a 13 step porting guide (incl. some build.prop entries) and troubleshooting: https://xdaforums.com/showthread.php?t=2483143

Regards, PW

PW.
[Android General] somebody100:
my tablet is tab 3-850f_S100030_161209_row

so i guess it could be possible to root...i am little be afriad to do that...

this step 6

#6 Now you need to boot to your custom recovery via the button combo for the device. (imo this tablet is a pain to boot into recovery compared to most devices) power off the phone. Wait a few seconds. Now hold the power button - then while still holding the power button press Volume up and then Volume down. Hold it for about a second then let them all go. If it worked then you will get the usual boot logo followed by the main twrp screen. Swipe to allow it to make modifications. If it boots into the Chinese recovery thing then just turn it off and try again. I would suggest getting an app that allows you to "reboot to recovery" once your all done and rooted. For root. Simply put the "Supersu sr3" zip in the storage of your tablet. Then flash it via twrp. "install - find where you put the zip - flash - reboot system" Done.

would someone be more specific to explain...i get my tab in boot mode with holding power buton and volume down an up......and in display is simbol of android with mesage no command..its confused me...

---------- Post added at 01:45 PM ---------- Previous post was at 01:28 PM ----------

i found a solution...press power button 2 seconds and quick press once volume up....

now i am in recovery boot menu...

so if someone to explain more specific this step 6

thanx for advices

regard
[Android General] pndwal:
Much more info in Lister of Smeg's thread (actually for TB3-850F) re recovery, root, stock ROMs etc, here:

https://xdaforums.com/android/help/lenovo-tab3-8-2016-custom-recovery-t3483454
[Android General] MotoJunkie01:
Yes very informative thread. Thank you for the link.
[Android General] pndwal:
See this post from Lister of Smeg's TB3-850F Thread, re root & recovery for TB3-850F. Note 'To Enter TWRP':

filedropper.com/tb3850froot (for files)

Quote:

Originally Posted by mtpc

Hey guys, It's me again. I managed to crack down the russian CAPTCHA and downloaded those files, and it just WORKS! I now have full root on my TB3-850f. I wrote down simple HOW-TO:

[Slightly ammended by Peter Wallace (Original Post #49)]

1) Copy SuperSU-v2.79-SR1-20161221223537.zip to the tablet

2) Enable developer and USB debugging

3) Open cmd (command Window) in folder with ADB and FASTBOOT

4) Type these commands:adb reboot bootloader

Then:fastboot oem unlock

5) Hold down power button and reboot. Repeat 2) and enable OEM UNLOCK

6) Repeat 3) and type:adb reboot bootloader

7) then type:fastboot boot recovery.img (must be copied in the same folder as adb.exe and fastboot.exe)

(Don't flash recovery yet - system will replace stock recovery before you have root)

8) Use TWRP to install SuperSU. - Now you have ROOT (Systemless) (can update to SR3, etc)

9) Repeat 3) and type: adb reboot bootloader

10) Type:fastboot flash recovery recovery.img - Now your new TWRP recovery will be permanent.

11) Use TWRP to reinstall SuperSU as lost in step 10 - Now you have ROOT (Systemless).

To Enter TWRP:

After powering down, press power, wait 1 sec then hold both vol up & down also (all 3 buttons) until vibrates.

I also uploaded the files here: filedropper.com/tb3850froot

Peter W:

Here is link to latest 850f rom:

http://lenovo-forums.ru/files/file/1549-lenovo-tab3-a8-tb3-850f_s100030_161209_row/

Which takes you to https://cloud.mail.ru/public/8T5R/RWCkuBz19
[Android General] MotoJunkie01:
Great stuff. Thank you much for the share.
[Android General] pndwal:
Looks like mtpc's filedropper.com/tb3850froot link no longer works.

However, looks like links to essential files, recovery img and modified SuperSU are working from this Russian Rooting Instruction page:

http://lenovo-forums.ru/topic/22185-lenovo-tab3-a8-rasshirennoe-rekaveri-twrp-i-root-prava/

Ie TWRP:

http://lenovo-forums.ru/applications/core/interface/file/attachment.php?id=67016

SuperSU:

http://lenovo-forums.ru/applications/core/interface/file/attachment.php?id=67022

Russian Unlocking Bootloader Instruction page here:

http://lenovo-forums.ru/topic/22153-lenovo-tab3-a8-разблокировка-загрузчика/
[Android General] Hemphiz:
Is that thread migrating over here or something?
[Android General] pndwal:
No. Reposted info from Lister's thread as somebody100 requested clarification on how to boot to recovery. This whole post is useful and mtpc's instructions re. achieving root and recovery are clear, so simply pasted it (as these steps may help others) with the pointer- Note 'To Enter TWRP'. Also, since mtpc's link to needed files in that post (ie. ref. to filedropper.com) seems to be broken, I also pasted post with links to these in lenovo-forums.ru.

Hoping MotoJunkie01 or someone is able to create custom ROM for TB3-850F. PW.
[Android General] stonedpsycho:
Thank you to OP and everyone who contributed in this thread as I now have root and custom recovery!

I did have a problem trying to flash TWRP at first but after renaming it to "recovery" it worked.
[Android General] kellogg9662:
I tried this method and even though I got a message saying it flashed successfully, now my tablet is stuck on the lenovo screen. I can't get it to boot up past that. Is there any way to fix this? Or is it safe to say it's bricked?
[Android General] MotoJunkie01:
If you're stuck on Lenovo screen you should be ok in terms of being able to fix it. Can you boot into recovery mode?

Follow the OP's instructions to see if you can boot into recovery.
[Android General] kellogg9662:
I've tried for a while but haven't succeeded in getting into recovery mode. I can't see the device in adb either. If it's bricked it's not the end of the world, that's always the risk you take with this kind of thing. I can only assume I skimmed the directions too quickly and did something wrong.