yashsingh1/xdaforums huggingface dataset:
[Android Q&A, Help & Troubleshooting] Tzul:
My job doesn't really involve Android, but I've studied this, more or less.

Glad to hear that the tablet is good. I'm still satisfied with my Tab 2 as well.

The latter, as far as I know.

Thanks for the property values. With those, I could find the small update you mentioned. Unfortunately it doesn't contain a complete boot.img file, but at least it contains a barebones scatter file (just the partition start addresses):

preloader 0x0
pgpt 0x0
proinfo 0x80000
nvram 0x380000
protect1 0x880000
protect2 0x1280000
lk 0x1c80000
para 0x1d00000
boot 0x1d80000
recovery 0x2d80000
logo 0x3d80000
expdb 0x4580000
seccfg 0x4f80000
oemkeystore 0x5000000
secro 0x5200000
keystore 0x5800000
tee1 0x6000000
tee2 0x6500000
frp 0x6a00000
nvdata 0x6b00000
metadata 0x8b00000
system 0xb000000
cache 0xcb000000
userdata 0xe5800000
flashinfo 0xFFFF0084
sgpt 0xFFFF0004

Exactly the same values I used for the preliminary scatter file that you found on the Lenovo forums.

If you like, you can try to use it with the SPFT to make a readback.

Download the latest SPFT, unzip it, find its "option.ini" file, open it, and at the very end change "ShowByScatter=false" to "ShowByScatter=true".

Download and install the USB Preloader driver (cdc-acm).

Finally, run the SPFT, load my scatter file, and make a readback.

If you hold down the power button for too long, the tablet will probably reboot.

Try this: Shut down the tablet. Hold volume up, then hold power. When the screen turns on, release the power button, but keep holding volume up.

That should take you to the boot menu or recovery. If not, you can still try to get there via "adb reboot recovery" or "adb reboot-bootloader" (for fastboot).

Yeah, on these MediaTek-based devices, that key combination usually takes you to the factory test menu. Avoid going there, you could mess something up.

The bottom-most menu entry gets you out of there (reboot). The menu entry with "eMMC" is "wipe eMMC" - sounds as if it would delete the entire internal flash memory (the eMMC chip), but in actuality, it just does as factory reset, i.e. it only wipes the /data partition (where all user apps and settings are stored). At least it's like that on every device I've tested so far.
[Android Q&A, Help & Troubleshooting] Lister Of Smeg:
Hi [MENTION=5919159]Tzul[/MENTION],

Well, after my chat to Lenovo and doing some more testing last night... I think my Tablet could be genuinely faulty...

You know I said how I can't enter Recovery (Power & Vol Up) despite you and Lenovo saying that it should work. Well Lenovo think and said it could be faulty and return to place of purchase.

I tried the ADB commands last night, the Reboot Bootloader worked and sent me into Fastboot. However the Reboot Recovery gives me this error...

Which I am wondering if I don't have a Recovery or it's corrupted...??

I am also failing to get those ReadBacks of either Boot.img or Recovery.img, as depsite having the Tablet off and clicking on the file names, and pointing it where to save. Nothing appears to happen, no data transfers...?? :(

Do you think I'll be able to get those files if I root the device, and use a Root File Manager???

Also, without any official firmware from Lenovo yet... If I root it, will I be able to unroot it by just doing a simple "Factory Reset" within Android OS, or does this keep the root do you know?? Never really used Factory Reset, as always wipe the device in a custom recovery....

Cheers, Lister
[Android Q&A, Help & Troubleshooting] Tzul:
That sounds quite unlikely to me. Have you tried what I wrote before? Start holding the volume up button before you turn on the tablet. Then press the power button to turn it on, release the power button again, but keep holding volume up all the time.

That's not an error, that is in fact the stock recovery! The menu is missing, but that's normal for some devices. There's a "secret" key combination you need to press to activate the menu. Try power+volume up again (or to be more specific, hold down the power button, then "click" the volume up button, then release the power button; do not hold down the power button for 10 seconds or longer, that'll probably reboot the tablet).

Are you sure you're doing everything correctly? When the tablet is off and you connect it to the PC via USB, Windows should play the "USB device connected" sound effect, quickly followed by the "USB device disconnected" sound effect. Take a look at the Windows device manager - the Preloader VCOM device should appear there for this brief period, and it must not have a warning triangle (that would be a sign of missing drivers).

Yes, that should work, BUT I would not advise it. Looking at the update file, I saw it uses the newer block-based format. That means if you change the system partition in any minor way, e.g. by installing root / su binaries there, future updates will fail! Therefore, you shouldn't do anything that could modify the system partition (installing root, or even running TWRP), until you have a backup of the original state.

No, a factory reset will not unroot! Root is either installed on the system partition (the old way), which Android considers read-only, or it is installed in a modified boot.img (the new way), which also won't be touched by Android. A factory reset, regardless whether performed by Android or a custom recovery, just wipes the data and cache partitions.
[Android Q&A, Help & Troubleshooting] Tzul:
The driver I linked can be installed with a simple right-click in Windows 8 and later. But in Windows 7, the installation procedure is more involved, as described in the included readme.

Yes, if you get the SPFT to work with your tablet, you can make a backup and restore it anytime you want.

The first time you run TWRP, it asks you whether or not you'd like to allow changes to the system partition. If you choose yes, TWRP will rename a certain system file on exit, and will also offer to install a SuperSU stub for root. You see, Android has a mechanism that restores the stock recovery on every Android boot! Therefore, TWRP will be automatically replaced by the stock recovery again, unless you allow TWRP to rename that file, or install SuperSU. Both these things will intentionally break that Android restore mechanism.

On your tablet, you should probably forbid TWRP to make those changes. But even if you do, other things in TWRP can still change the system partition regardless. Installing the zip files for Xposed or SuperSU, for example. Or even restoring a TWRP backup of the system partition (because they are file based, but a block-based update doesn't just care about the file contents, but also about where exactly the files are located on the partition/disk, which will change with a file-based restore).

That's why "systemless" Root and Xposed are a thing these days. They don't install the files to the system partition anymore like they used to, but somewhere else (the ramdisk of the boot image, as far as I know), and use some trickery to make the files appear in the filesystem where they are expected.

Concerning OTA updates: they will fail if the system partition was modified. So if you want to install one, you either have to roll back to an unmodified system and stock recovery, then install the update, then install root, Xposed, etc. again (tedious). Or you can modify the updater-script inside the update, and make it work with modified systems, then install the adjusted update with TWRP. But that requires know-how and will only work with the old file-based updates, not the new block-based ones.

No. As just mentioned, TWRP backs up the files (their content), which is not enough for block level accuracy. You need a system image backup. Which can also be made with TWRP, if it has been configured properly.

Yes, but again, you need to backup and restore the system image (the entire partition, including "empty" space, not just the files as TWRP normally does).

It has nothing to do with Samsung vs. Lenovo. It's about the chipset - MediaTek in your case. A Lenovo device with a Qualcomm chip, for example, will have a different partition layout and obviously won't work with the SPFT. And most of the things I just talked about (file-based vs. block-based updates, the "sanctity" of the system partition, etc.) are general Android things and not specific to the chipset.
[Android Q&A, Help & Troubleshooting] Tzul:
That's the same error the other person on the Lenovo forum had. I have a feeling that the driver isn't installed correctly. Have you looked at the Windows device manager, Ports (Com & LPT) section? Does a new device appear there after connecting the powered-off tablet, and does that device NOT have a warning triangle?

Maybe you could try the SPFT on a Windows 8 or 10 machine, where the signed driver can be installed with the simple right-click method. Otherwise, you could find an install an unsigned driver for Windows 7, and try again. Maybe this error is also caused by an incorrect scatter file, wrong download agent, or bug in the specific SPFT version. You could try an older version such as v5.1516. Here's someone who encountered the same error and "fixed" it by using this older version and a slower PC...

Yes. You should probably go with systemless root on this tablet, but whether the system or boot image get modified, an OTA update will fail either way if it does integrity checks. So there's no way around making backups of the untouched partitions and restoring them when necessary.

That option might or might not exist in your Samsung's TWRP. Usually, newer TWRPs are configured to have a "System Image" entry in the Install -> Install Image partition list, so that it is possible to flash a system.img file easily from within TWRP. This same "System Image" entry can also be made visible in the Backup/Restore partition list, but normally it isn't.

Well, you're not supposed to mess with these devices. Only a fraction of users install root or Xposed anyway. I've never tried the "Lenovo Smart Assistant", so I can't say anything about that.

Anyway, you're welcome. :)
[Android Q&A, Help & Troubleshooting] Lister Of Smeg:
Hi [MENTION=5919159]Tzul[/MENTION],

I've done a little more playing around, and I think the fault lays in either the DA (Download Agent) or the SPFT App itself....

As when reading the error back, and the resolution... It does mention that the DA may have issues (which I guess is the database of supported hardware). Or when I rename the Platform inside the scatter file, to the exact model as to what I have... The App then complains it's not currently supported and that I need a newer version....

So it looks like I am stuck, until a new version comes out... :(

Any idea how frequent these come out...?? Looking at the file dates, it was September that this came out... which kinda hope it may of supported by now... That said even Lenovo's own "Fix It App, Lenovo Smart Assistant" don't work or support it either... lol

Cheers, Lister
[Android Q&A, Help & Troubleshooting] Tzul:
Does a "MediaTek Preloader USB VCOM" device briefly appear in the device manager's "Ports" category when you connect the tablet (turned off)? Something like this. It will disappear again 2 seconds or so after connecting the tablet, unless the SPFT initiated a data transfer.

Systemless root just requires installing SuperSU in a certain way. You can modify its installation script to force systemless, or simply create the file /data/.supersu with the content "SYSTEMLESS=true", e.g. by executing the command

echo SYSTEMLESS=true>>/data/.supersu

in TWRP's terminal. If you then use TWRP to install the latest SuperSU zip, it should do the systemless installation automatically.

Yeah, that is nonsense.

The SPFT comes with different download agents. You can load them via the "choose" button. The default one is "MTK_AllInOne_DA", but there's also DA_PL, DA_PL_CRYPTO20, DA_SWSEC, DA_SWSEC_CRYPTO20. I can't tell you what the differences are or if your tablet requires a specific one.

That's not surprising, and I have mentioned this in the other topic you found. It's normal that scatter files sometimes don't list the exact chip type in the platform field. My Tab 2 A10-70F for example has an MT8165, but the scatter file says "platform: MT6752". The name that is used there must exist in the config files of the SPFT (see platform.xml and storage_setting.xml, for example), and the settings that are defined there must be "compatible" with your actual chip type.

I don't think that waiting for SPFT updates will help. Like I wrote above, the Tab 2 A8-50F was based on the same MT8161 chip, and its scatter file lists "platform: MT6735". There's either something strange going on with your Tab3, or it's a driver issue.
[Android Q&A, Help & Troubleshooting] Lister Of Smeg:
Hi [MENTION=5919159]Tzul[/MENTION],

Does it all depend on which driver, any others from this list suitable?

This is what I get under ports now, that I can choose from..

Thanks, Lister
[Android Q&A, Help & Troubleshooting] Lister Of Smeg:
Hi [MENTION=5919159]Tzul[/MENTION],

It looks like it maybe the device?? Thought I'd try see if there was another program that could try and access it... as SPFT doesn't want to know it at the moment.

Then this popped up... It may just be that this software is really old, and so doesn't know the structure of this device... But it appears to say ROM Structure not normal, or something...?

Thanks, Lister
[Android Q&A, Help & Troubleshooting] Tzul:
I've heard that some devices require holding all three buttons, but this is weird. Anyway, nice find.

The SuperSU installation script is quite involved now. It should automatically detect whether or not a systemless install is necessary, and patch the boot image automatically when required. You can override the installer's behavior by setting the SYSTEMLESS variable, and you might also have to specify some more, e.g. BOOTIMAGE=... if it can't automatically find the boot partition. It should work, but I haven't tried it yet myself.

I've used the SPFT without problems in Windows 7 32 bit, and Windows 8 and 10 x64.

I think it's good to have them all installed, but normally you'd only need the "MediaTek PreLoader USB VCOM".

I know that program, it's MtkDroidTools. It has been discontinued, and it does not support the newer chips, particuarly not the modern GPT (GUID Partition Table) scheme.
[Android Q&A, Help & Troubleshooting] 14gramin:
I was having problem with OTA update not working as well.

I just found a solution that works.

If you have an external SD card Just remove it (you will get a message about reinserting it or forget it DON'T DO EITHER) and run OTA update normally and it will work.

I have even put the card (64 gig) back in before the update finishes.

I have a theory that OTA writes the upgrade file to the external card then when it boots into recovery the system looks for the file on internal memory and can't find it so shows Android fallen down and the word "Error".
[Android Q&A, Help & Troubleshooting] Lister Of Smeg:
Hi [MENTION=3438834]14gramin[/MENTION],

Thank you for the info, this may help others who are experiencing problems trying to update their Tablets...

However, the original nature of this post / request, was trying to find a way to make a BACKUP of the existing rom/firmware. As Lenovo (for reasons, ONLY KNOWN TO THEM...) do not want to share a stock firmware. So should you have problems with your Tablet, rooting, bricking or whatever reason to RESTORE LIKE NEW.

You'll have to send the device off to Lenovo (at your expense) possibly for them to turn around and say NOT COVERED... wasting time and money. Where as other companies offer firmware and tools for you to restore your Tablet freely (such Samsung)

[MENTION=5919159]Tzul[/MENTION], has very kindly and patiently been trying to support me on this.... However (which I blame Lenovo, and updated hardware) all previous known methods do not appear to be working as of yet... :( I've kinda of stepped back on this for a bit, as (and I maybe wrong) believe my model (MT8161P, and not MT8161) maybe different unsupported hardware. As it took a mission just to be able to access recovery on this device.

As I've had the Tablet for nearly 2x weeks, and it belongs to my dad... Thought I'd best give him access to his own device... ;) LOL

So I'll wait in vain, in the off chance and hope that some new tools come out that may support my Tablet better... ;)

I have made a brief discovery today, that may or may not help....

I appear to have found some new drivers (which may or may not work for this device, considering they are more based for Qualcomm hardware) from this post. (Yet to try/test this yet)

Then found 2x places hosting firmware... Although they are not English based firmware, as it mentions Arabic and Russian I think.... (Even though it says ROW / Rest Of The World in firmware).

http://forum.a2phone.ir/download-ce...farsi-arabic-turkey-android-6-0-firmware.html

http://www.kashan-gsm.com/thread91637.html

http://www.dlgsm.com/register.php?f...zip&dir=/FLASH-FILES/LENOVO/T_Series/TB3-850F

So will come back to this at some point, but for now... running it as STOCK and just installed general Apps. Bit annoying cannot run some rooted Apps which make Android devices more configurable and powerful, at the risk of BRICKING it... :(

Cheers, Lister
[Android Q&A, Help & Troubleshooting] stibot:
Hello, I also would like to root Lenovo TB3-850F. I did read the thread and have a question. How exactly TWRP does install su binary? Does it flash the ROM (possibly with kernel) or does it only use some basic commands/scripts to copy it to the filesystem?

The trouble here is we do not have copy of kernel from TB3-850F. I understood TWRP doesn't need to be flashed in order to get su installed: TWRP can be run only once without being flashed (fastboot boot image).

Could I use TWRP for similar device (I understood from what Tzul has written that Lenovo Tab 2 could be such one), run it (without flashing as suggested above) and let it ONLY to install SuperSU to gain root without touching enything else (to avoid bricking)?

Or--could I build new TWRP using Lenovo Tab 2 (or other similar device) kernel, and use that to install SuperSU without replacing kernel/ROM? Is there any risk of bricking?

Thanks
[Android Q&A, Help & Troubleshooting] mtpc:
How to backup/unbrick TB3-850F

Hi guys,

I'm the dude who bricked his tablet from Lenovo Forums... Tzul tried to help me but with no luck.

Yesterday I managed to fully backup that bricked tablet and even unbricked it using some russian ROM for TB3-850M. I think the problem was in the driver or Scatter file (or both). Just use the SPFlashTools, driver and scatter from the russian ROM. Oh and use download agent DA_SWSEC . Here is the link:

well apparently I am not authorised to post links here, so google TB3-850M_S100029_160924_ROW on russian site novo-forums

Anyway, I still need to root it, so if I can help somehow (share the backup or somenthing) just let me know. Thanks
[Android Q&A, Help & Troubleshooting] brarry:
I've downloaded and tested this, and yes, it works. I've checked different combinations, and the problem is in fact the DA. Also Tzul's scatter file doesn't quite fit this tablet. The scatter file in the russion ROM fits and this should be used (but that's not the reason for the error given by SPFT).

I could make a full backup and verify that the images are OK (system.img can be mounted, "file boot" and "file recovery" say "Android bootimg").

Key combo for recovery mode

I had the same problem as Lister: power and vol- gets you in that chinese test menu and when you hold all 3 buttons it doesn't boot. This is how you do it:

press and hold power

wait 1 second

press and hold vol+ and vol-

when it vibrates, relase all buttons

Once you get the timing, you can do it consistently.

harry
[Android Q&A, Help & Troubleshooting] Lister Of Smeg:
Hi [MENTION=1662557]mtpc[/MENTION] and [MENTION=7905341]brarry[/MENTION],

Glad to hear you managed to get your Tablet up and running again MTPC.... bet you're happier now!!! Gotta be honest, I find it crazy that Lenovo are so unwilling to want to help their users. Most other manufacturers don't shy away from publicly posting their firmware's and restore methods online, such as Samsung. As I tried to ask them for the firmware on numerous occasions, only to be told "why do I want it.... and there is no need to have it"

Well, if it's bricked I do... and rather than send it off in the post, where it could get lost or damaged further, at MY expense... With a bit of know how, it's something we can ALL DO FOR FREE!!!!

Anyway, that said, I've been trying to work this out for a few weeks now, with the great help of [MENTION=5919159]Tzul[/MENTION]. Would one of you kind gentlemen be able to package up the firmware or scatter files used from the Russian site onto a public filehost please?

I've tried that site, and keep getting stuck in a loop, going back to the download page. If someone could grab it, and re-upload it... Would be super coool !!!

So with these files, have you been able to take a FULL BACKUP of of the TB3-850F model (even though thats for the TB3-850M) model...? And then restored it back to the device ok, with no problems....???

Is the M version, just the same as the F version.... just it has LTE ?

Cheers, Lister
[Android Q&A, Help & Troubleshooting] Tzul:
It actually fits without problem and is almost identical. The only two differences are the project name (which is also reflected in the preloader filename), and the size of the userdata partition. I used the real size, the other scatter file uses a truncated size (which is normal). Both of these differences don't really matter.

[MENTION=5273366]Lister Of Smeg[/MENTION] - Here's the direct link. But a word of caution: while the firmwares of the Lenovo WiFi+3G/4G tablets (e.g. TB3-850M) are usually compatible with the corresponding WiFi only tablets (e.g. TB3-850F), some problems might occur if you flash one on the other.
[Android Q&A, Help & Troubleshooting] mtpc:
hi,

Yes I was able to do full backup, but I only flashed boot and recovery partition from TB3-850M firmware, because I suspected one of them to be corrupted in my tablet (it was bricked). It worked well so I didn't try to flash any other partitions - I didn't want take the risk.

I'm really looking forward to root this tablet, and I'm glad I could cotribute(a little) to the process of getting a root :)

Here is my backup: ufile.io/5f0bb

If you need anything else, just write in this thread and I will try to help.
[Android Q&A, Help & Troubleshooting] brarry:
Yes, sorry, I got confused about which scatter file you guys where talking about and compared with the one you made for the Tab2. The one for the Tab3 is indeed the same.

I am looking into building TWRP for this tablet. But I'm a complete noob when it comes to building Android, so it could take some time and I make no promises.

[MENTION=5919159]Tzul[/MENTION]: Can you suggest a device tree I can use as a starting point for this?
[Android Q&A, Help & Troubleshooting] wantagewill:
This is a cracking little tablet, would be perfect if it could be rooted just to get Adaway on it.

Hope someone can do it. I'm following with interest.

Best, Will
[Android Q&A, Help & Troubleshooting] voland34:
Same here! I can't find no rooting method (nor custom recovery; not even stock rom). So following with high interest as well...