yashsingh1/xdaforums huggingface dataset:
[Android General] limited_imagination:
Wow, that was a commitment. Thank you! (and clicked.)

Especially interesting about the history and politics of SuperSU and Chainfire.

OK, you have persuaded me.

So in the state that my device currently sits, rooted with SuperSU Free v.2.82-SR5 as MotoJunkie01 provided in the OP, can you tell me if Magisk will play nicely?

Or should I start clean, with a SPFT reflash of a completely clean and unrooted 6.0 OS?

Magisk Hide sounds interesting, as I was surprised to see that my TB3-850F was denied access to in-flight entertainment services on a couple of airlines, because of the root. At the time, I thought that was really overkill for airline security, because surely the inflight info system has no connection whatsoever to the actual controls of the aircraft. Or at least, hopefully not, anyway! Remember when Chrysler cars got hacked through their stereos a few years ago? https://www.wired.com/2015/07/hackers-remotely-kill-jeep-highway/

Those files I posted were just as MotoJunkie01 posted them in the OP, and yes, the TWRP.img doesn't have a version in the filename.

It is TWRP is 3.0.3 by Jemmini.

If you feel like hosting, you could change the filename in the .zip.
[Android General] pndwal:
Yeah man, you don't say!

Thanks. :good:

Take it you're on stock still.

No need to start clean, usually plays nicely, and you have a plethora of options, but some possible complications:

Not sure if you'll get recovery overwrite by stock ROM when you clean up/remove SU as I haven't been there. However, this will (can) only occur if you boot stock ROM without root.

Using SuperSU manager app SU cleanup/removal options first will probably work, but sometimes doesn't.*

Could try official SuperSU removal zip from TWRP (search for it) too.* Think this is more foolproof than manager cleanup. (Works like official Magisk removal zip.)

Magisk itself can often handle previous SU cleanup when flashing in TWRP, but I've had this fail too.* You could just try flashing and see if you get errors.

*As problems with these methods all revolve around their ability to restore an archived stock or unrooted (unmodified) boot.img, the solution is the same for each, and very simple: simply extract boot.img from stock or unrooted ROM and flash it in TWRP. (I've mentioned this to you before.) Then Magisk zip will definitely flash without errors.

You could simply uninstall SuperSU manager, then flash original unmodified boot.img and avoid the official methods altogether as this will just work.

I think our LOS comes pre-rooted. Either way, Magisk handles and modifies this fine when unaltered by another SU or other mod like Exposed etc.

Yeah, more important as time passes. We still have initial failure with Magisk Hide, but this can be overcome on most devices. There are Magisk threads devoted to this, but I haven't tried hard with TB3-850F.

[MENTION=631273]Chainfire[/MENTION] actually introduced SU Hide feature, but this requires constant tweaking and variation (Cat and Mouse game with Googles CTS), and this is an artform refined by [MENTION=4470081]topjohnwu[/MENTION].

Probably unaltered as obtained from:

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

So have to blame the Russians, and thank them at the same time :) .

Interestingly, the original SU used to obtain root on our device is hosted here too - a Cobra-patched SuperSU Pro .zip. PW
[Android General] pndwal:
How's Magisk?
[Android General] limited_imagination:
Ha ha, you're worse than my clients for holding my feet to the fire. I have a deadline for this Monday where I have to keep my eye on the ball, so time-sucking distractions like that have to wait a few days.

I can't even allow myself to open the box containing a new Xiaomi Mi Pad 4 that just showed up after riding a slow boat from China.

I ordered that about a month ago, when I was sure I had bricked the TB3-850F. About 30% more money than the TB3-850F initially cost me, for about 4 times the horsepower, and a pretty active dev community. Most interestingly, [MENTION=4898097]arter97[/MENTION] has developed a working custom kernel and he seems open to my request to enable serial USB support on that tablet. So that was all compelling stuff.

I still intend to keep playing with the TB3-850F though, now that it's back to being alive. I will attack the kernel source code for it again at some point, to see if I can make it work when flashed to the device. Compiling it is one thing, but getting it to actually work is an order of magnitude greater, given the incomplete source code that Lenovo released. At least now I know the precise steps to unsign the boot image, then unpack/repack it in AIK, and then reflash it with TWRP, so I can eliminate that whole process as a potential source of error when replacing the kernel.

I'll let you know about Magisk and LOS on the TB3-850F next week, when I can make time for it.
[Android General] pndwal:
No worries - you're still alive. Didn't mean to be annoying.

Understand. - My problem also - got to watch the TSDs.

Thanks for heads up re Mi Pad & development - might took into those too!

Please remind me of serial USB uses.

Glad to hear of intentions. Look forward to that.

Great. PW.
[Android General] pndwal:
Sorry, fixed link. (XDA labs attached comma to url and I didn't check. - it often messes up formatting. Repostioned comma.)

Glad Tablet is going well for you now. PW.
[Android General] Never_Sm1le:
Could anyone tell me how to enter recovery or fastboot mode using hardware keys?
[Android General] AeonFlux1603:
Tricky. But this works to boot you into recovery: Power your device completely off. Hold Volume Up and Down simultaneously then press Power button also. Now it's a timing thing....release power before you feel the vibration prompting the Lenovo logo, but continue holding Volume + & -

Recovery mode will boot.
[Android General] pndwal:
Failing AF's method, this is the way established in early days:

To Enter TWRP:

After powering down wait at least 5 seconds after vibration, then press power, wait between 0.5 & 1 sec, then hold both vol up & down also (all 3 buttons) until vibrates. This timing is critical, but will boot to TWRP every time once you get it right.

See post #404 - Useful Stuff. PW
[Android General] pndwal:
Welcome to Lenovo LOS club!

Good decision, but as I said, could have tried official SuperSU removal zip TWRP flash - more foolproof than manager cleanup. Also, flashing original unmodified boot.img will just work, and will fix bootloop too assuming you can enter TWRP and you flash new Magisk SU immediately after, and before booting to system (stock).

I hope it does change. And yes, SuperSU was a great SU that generally just worked.

The real beauty of Magisk is the value-added features it introduces, ie:

Module platform for other devs to contribute flashable Mod(ule)s that are easy to toggle on/off to test their effect, with updates arriving thru Magisk Manager, as well as ability to disable "fatal" mods in TWRP.

Incorporated setup of BusyBox (as module). - No need to use standalone versions with awkward binary updates and settings anymore.

Magisk Hide, which allows banking and other security-centric apps to work on our rooted devices.

Advanced Settings for:

Preserve force encryption, and

Preserve AVB 2.0/dm-verity

It also has much simpler manager settings and update notifications, and VERY importantly is fully open source.

Yes, I've found the same - such mods are often ineffective without fuller kernel support, and, I guess, as with Kernel Auditor, may have negative effects such as overheating and blackscreen crashes without proper support. The mods should be considered experimental unless confirmed to work on a particular device / ROM / kernel IMHO, but many are very useful.

Thanks for the interesting benchmark test results.

I'm looking forward to LOS14.1 for TB3-850F Mark II. [MENTION=9720847]AeonFlux1603[/MENTION] has already made good headway with tweaks and refinements including working Google Camera app, fixed Charge animation, etc, but just needs time for a bit more polishing.

Sounds like a great endgame! - and I hope you still have the fight not to be defeated.

"The most depressing thing about it is that I wasn't even getting out of the middle game to an endgame. I don't ever remember an endgame..." Peter Biyiasas

"I like the moment when I break a man's ego." Bobby Fischer (of the above.)

And from someone else who appreciated a good endgame:

"Nervous energy is the ammunition we take into any mental battle. If you don’t have enough of it, your concentration will fade. If you have a surplus, the results will explode."

"The loser knows that he made a mistake, that something went wrong, and he will work hard to improve for next time. The happy winner often assumes he won simply because he is great. Typically, however, the winner is just the player who made the next-to-last mistake."

"If you program a machine, you know what it’s capable of. If the machine is programming itself, who knows what it might do?"

"Deep Blue was intelligent the way your programmable alarm clock is intelligent. Not that losing to a $10 million alarm clock made me feel any better."

- Garry Kasparov

Seriously though, this one may even be marketable - more practical than Deep Blue, especially if it can be made to work universally with OBD interfaces! Hope you relish a challenging game.

Regards, PW.
[Android General] AeonFlux1603:
:) Always some great thoughts, cool quotes and deep thought phrases from [MENTION=7550078]pndwal[/MENTION].
[Android General] wezroot2k:
Hey my peoples what s up

Well haven't got my PC back up yet but been monitoring the both this and other the other tb3_850f thread from my tablet and loving the post so far from AF and LI .

But there are few things I took note of especially the LI'S notes on Magisks and certain modules especially LKT I've been using lot and GPU turbo for a while now and did notice an improvement in speed and none of the crashes spoken about I've playing soocer spirits alot which to me is memory intensive games and lot have help with the speed both in the booting and gameplay. Also there are two other modules that seems to work FDE ai and NFS INJECTION so maybe you can check out those modules.

But the LOS I've been using is a version that I modify couples months ago and it's been working fine, wanted to upload it but decided to wait on AF version he his working on currently. But due to these people are having I am going to upload my modded version as a test ROM as soon as possible when I get my PC back in working order.

Thank you

Nuff Respect PW LI and AF:good:
[Android General] pndwal:
Great stuff. Were you able to modify kernel? PW
[Android General] wezroot2k:
No this modded ROM I am using is packaged with our original kernel boot.IMG, with some minor app drawer tweaks most notable taking out the dialer and messaging apps.
[Android General] pndwal:
Thanks. I thought as much, but wondered if this may account for your different experience with LKT and GPU turbo mods. These should depend on kernel support, and perform the same with the same kernel.

My Ascend Y550 LOS custom ROM, for example, currently doesn't support most of these mods as our longtime dev ( [MENTION=4479868]desalesouche[/MENTION] ) focusses on fixing bugs / commits and updating sources, so his ROMs are smooth and bug free, but suffer overheating and black screen freezes with Kernel Aduitor and other mods.

Another dev ( [MENTION=6864096]NATO66613[/MENTION] ), who focused on performance was able to adapt [MENTION=4479868]desalesouche[/MENTION]'s kernel to produce alternative kernels (Soviet Bastard, etc) with extra functionality for a while, but has since moved on. Many of these Magisk mods work well with his kernel, as do Kernel Aduitor enhancements - enthropy, etc. He even had support for quick-charge and overclocking (from original 1.4 to 1.84GHZ - SD410 SOC), however his kernels are now unfortunately comparatively old.

I'm not sure how such functionality is added, - presumably using Android Kitchen or the like - but it can be done.

It would be great if someone with more knowledge could shed light on sources for such kernel enhancements, and how they can be added to our TB3-850F kernel. PW
[Android General] wezroot2k:
Maybe [MENTION=5522475]limited_imagination[/MENTION] could give us insight on how to do this due to fact he been working on something similar.

LI where are you man?
[Android General] r&xp:
tb3-850f rooting and recovery personal experience

Hi all, just sharing my experience after successfully rooting and adding custom recovery.

Essenstial!!!! Do NOT allow twrp to make changes to the system (when it presents you with the choice), or you WILL SOFT BRICK the device.

1. unlock bootloader as described. (fastboot oem unlock)

2. restart phone (restart to system) wait and set up your device. Reason for this step is that the first time the bootloader is unlocked, the tablet performs an automatic factory reset. At this point you will need to re-enable developer options and usb debugging.

3. reboot to fastboot and boot to recovery. Just boot to recovery, not install it yet (fastboot boot twrp.img)

3. flash latest supersu.zip and reboot to system again!

4. Once you have the device rooted (you have a working supersu app) install the latest busybox you can find(as root). Install it normally as .apk. No need to flash it.

5. Now back to "fastboot boot twrp.img" and this time, flash twrp.img to recovery.

6. Final - reboot to system and enjoy!

(actually my last step is to install rootessentials as it provides an option to reboot to recovery. Trying the combination keys did nothing for me, or just poped up the chinese options menu. That does not mean the recovery has not been installed correctly. Booting to recovery from rootessential menu, boots straight to twrp)

Hope I could help, thanks to everyone on the thread as it took some time reading here and also some trial and error to get this to work. :good: :highfive:
[Android General] Kithering:
I think this ended up happening to me and my Tab3 is soft bricked, did you find this out after having the same thing happen? If so is how would I fix this? I've tried every power/vol button combination I have been able to find discussed and every time it leads to teamwins openrecoveryscript screen failing and leading to bootloop, I cannot figure out how to force adb communication as outlined in a previous post.
[Android General] r&xp:
Hello! Unfortunately, yes I found out the hard way... :) The only solution (at least I) found, was to re-flash the rom using SP Flashtool. Then root and flash as I described in the steps above. Now the tablet is fine, both with root and custom recovery!

At the time of boot loops it is nearly impossible to establish communication with the device. I found some scripts that supposedly slowed down the time of bootloop, to give time to connect and force files, but nothing worked for me.

Let me know if I can help you out with how to flash to stock rom if you so decide!!
[Android General] Kithering:
I have been trying to figure out how myself but I can't seem to find a scatter file for this particular device, clearly I can't make one with the methods I've found can be done. Might you have one or are they device specific as opposed to model specific? This will be my first time using SP Flashtool and I'm not fully clear on what I'm doing though I've found out the general idea from a guide or two.
[Android General] r&xp:
From my experience the 100% correct scatter file, only resides in a stockrom.zip file. The zip needs to unzipped, revealing all the files to be flashed to the device. Once you use the specific file, all the files are automatically loaded in SP Flashtool and are ready to be downloaded to the tablet in their correct partitions.

You need to have a correct ROM for the device, and I would definitely stay away from mixing scatter file and random image files.

Try a google search about TB3-850F firmware, or stock rom or similar. Should be around 1.5Gb :o:o:good:

Also recheck the xda forums for TB3-850f Unbrick root recovery. After our conversation today , I uploaded some instructions I found helpful from my experience.
[Android General] MotoJunkie01:
I am currently compiling a pure Stock Android 6.0 ROM for the TB3-850F which can simply be flashed via TWRP, recovery, without the need for the SP Flash Tool or scatter file. I've made a Nandroid backup of the unmodified stock ROM, converted the system.ext4.win file into a flashable system folder, in conjunction with a compatible META-INF with updater-script and stock boot.img. I am presently testing the updater-script to ensure successful booting. If there are no errors, I'll post the ROM and a short guide on installation in the next couple days.

My modified, debloated, pre-rooted ROM for this tablet is being tested with the same META-INF, so hopefully both ROMs are near completion, as soon as I can give everything a thorough preliminary testing.

---------- Post added at 05:09 PM ---------- Previous post was at 05:02 PM ----------

One thing I've found that oftentimes works in the event of a bootloop brick, is to completely power the tablet down, hold Volume + for around 5 seconds and, while continuing to hold, connect the micro USB to the device from the PC connection. This will usually force communication between the device and PC, enabling a means to flash a stock or custom recovery.
[Android General] stonedpsycho:
Comment number 24 here from pndwal - https://xdaforums.com/thinkpad-tablet/general/lenovo-tb3-850f-root-t3397017/page3

That is a link to the stock rom, has drivers and spft included. Tested working by myself. Read my comment #25 on the same thread posted above if you have problems with the vcom driver. With spft, select the scatter file from the download and for the DA select the one named "all in one" Just make sure you press download on spft before connecting your turned off tablet to your computer when ready to flash.
[Android General] MotoJunkie01:
[MENTION=5003632]stonedpsycho[/MENTION], send me a PM if you get a moment. I tried to PM you but was unable for some reason. I wanted to collaborate ideas with you on future support for this device and get your thoughts on some things. Thanks
[Android General] pndwal:
As [MENTION=5003632]stonedpsycho[/MENTION] said, see my post #24 here for clear rooting instructions (c/o [MENTION=1662557]mtpc[/MENTION] in Lister's thread. I have 2 devices rooted this way, never had soft brick / bootloop probs following this method) as well as link to latest 850f stock ROM (Zip includes flashtool, scatterfile etc) just in case tablet gets messed up as yours did.

(In Lister's thread post 66:

https://xdaforums.com/android/help/lenovo-tab3-8-2016-custom-recovery-t3483454)

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)

See post #26 (In Lister's thread #71) here for working file links if following rooting instructions.

'To Enter TWRP' method in above post (#24 here, #66 Lister's) works every time using key combination from powered off state if followed correctly.

Hope it helps,

PW
[Android General] eagors93:
Hi, could anyone provide me with a link for stock firmware for TB3-850M (with LTE support)? Unfortunately I'm stuck in bootloop after allowing TWRP to make changes to the system. Root Integrity Check shows error: "Error: /system/recovery-from-boot.bak is new". Help!

EDIT: I found the ROM that seems to be for my tablet on this russian website:

https://translate.google.pl/transla...fiversion/index.php?t764969-80.html&sandbox=1

I downloaded the file that says: TB3-850M S100034 170217 ROW (the last one)

BUT! How do I know if this is FOR SURE the ROM for my tablet? If I understand correctly, flashing the incorrect ROM will result in permanently bricking the device, right? Can anyone help me?

I checked on the box and it says the model is TB3-850M (NOT Yoga)
[Android General] pndwal:
Yes, TB3-850M S100034 170217 ROW is latest for TB3-850M model, mentioned here:

http://4pda.ru/forum/index.php?showtopic=764969&st=320

Available here:

http://lenovo-forums.ru/files/file/1621-lenovo-tab3-a8-tb3-850m_s100034_170217_row/

Link:

https://cloud.mail.ru/public/LHhe/NkpAi7WuL

About This File

1.17 GB

Lenovo Tab3 A8 (TB3-850M) - official firmware

TB3-850M_S100034_170217_ROW (ROW version with LTE module)

Creator: Lenovo

OS: 6.0

Build Date: 02/17/2017

Description:

android 6.0

AOSP

2 sim / memory card

Voice call + SMS

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

Archive password: lenovo-forums.ru

Seems these files come with the drivers and spft needed.

If you have a problem with the Vcom driver, what worked for others was holding the volume down button and plugging the usb in at the same time while spft was in download mode.

Seems It also re-locks the bootloader.

Custom ROM - TB3-850M_Corsair_Edition (Android 6.0, odex, root, pure) - for 850M (not 850F) also available at:

http://4pda.ru/forum/index.php?showtopic=764969&st=320

Hope it helps, PW.
[Android General] eagors93:
Thank you very much, your response was very helpful. I'm from Europe so this ROM is perfect.

Will I need to install any drivers if my tablet is recognized by my PC without problems (fastboot works)?

What's the best method to install this ROM now? I have never used SP Flash Tool, but I think I will try to find some tutorial. I know that I need a scatter file and I've seen it is provided with the ROM, although I don't know what mode should I put my tablet in before flashing via SP Flash Tool. Should I boot to fastboot?
[Android General] eagors93:
OK, I found some tutorials and am ready to use SP Flash Tool. However, I'm not sure which Download Agent to use. There are 4 bin files:

- lk-sign.bin

- logo-sign.bin

- preloader_lcsh8735m_6_co.bin

- trustzone-sign.bin

Unfortunately, none of the tutorials seem to mention that (?).

Also, can I safely flash only the SYSTEM partition?

Should I use Download or Format All + Download method?

EDIT: I found the program folder contains "MTK_AllInOne_DA.bin" - I assume I should use that?
[Android General] MotoJunkie01:
Why SP Flash Tool? There are other methods which are far less tedious.
[Android General] eagors93:
What do you suggest, MotoJunkie01?

I get BROM ERROR : S_BROM_DOWNLOAD_DA_FAIL (2004) in SP Flash Tool - any ideas?
[Android General] MotoJunkie01:
Ok, what is your main objective? Are you just needing to restore factory firmware?
[Android General] eagors93:
I eventually got it working by pressing volume down when connecting cable. I also ran SP Flash Tool in WindowsXP SP3 compatibility mode. I omitted preloader and recovery, since there was no need to reflash them. Everything is fine now.

I even managed to flash TWRP recovery and install custom Corsair ROM (warning: it's for TB3-850M model!). So far everything's good. Finally enjoying my rooted device! I've also learned a lot. Thank you all for the help and knowledge.

It really is essential not to give TWRP permission to make changes to system partition when using "fastboot boot", as r&xp said in this topic. It what's bricked my device. If it weren't for the 4pda community, I would be stuck.
[Android General] MotoJunkie01:
Yes, you are very correct on the TWRP information. Very glad you got your device working as well.
[Android General] pndwal:
Glad it got you going.

Volume down trick was from [MENTION=5003632]stonedpsycho[/MENTION] originally.

Happy Custom TB3-850M Corsair ROM was good for you too.

PW