Lenovo Tab 3 8/TB3-850F -
Android 6.0 Stock Firmware Images
DISCLAIMER: As always, flashing your device - with either stock or custom firmware - involves an inherent risk of bricking or otherwise rendering your device inoperable. I am not responsible for any good or bad resulting from your use of these firmware images or this thread.
DEVICE SPECIFICATIONS:
Model: Lenovo Tab 3 8"(TB3-850F)
Android Version: 6.0 Marshmallow
Kernel Version: 3.18.19
Board Platform: MediaTek MT6735m (1.0 GHz)
Build No: TB3-850F_S100031_171010_ROW
Software Version: TB3-850F_160412
SDK Version: 23
Build ID: MRA58K
Android Security Patch Level: 9/05/2017
Build Date: 10/10/2017
NOTE:
First & foremost, these partition images will not restore your device completely back to factory/stock condition. They will restore your Android OS, boot logo, boot image & recovery to stock condition. Other vital partitions of your device, such as /lk (the primary bootloader) are not restored by flashing these images. To revert to an unmodified factory state, you will need to visit @r&xp's thread mentioned below and flash your device with stock firmware using the SP Flash Tool, which will also re-lock your bootloader.
This firmware thread is not intended as a tutorial or guide for flashing or restoring your Lenovo Tab 3 back to stock condition. Rather, this is intended as a resource for stock images, device drivers, etc. However, some rudimentary instructions are provided, which will enable you to install these images and restore your device back to mostly stock condition. NOTE: IF YOUR DEVICE IS BRICKED (UNABLE TO BOOT INTO EITHER RECOVERY OR FASTBOOT MODE), THESE FIRMWARE IMAGES WILL BE OF NO BENEFIT. INSTEAD, PLEASE VISIT THE FOLLOWING THREAD BY XDA MEMBER @r&xp , WHICH WILL GIVE YOU THE NECESSARY FILES AND PRECISE INSTRUCTIONS FOR UNBRICKING & RESTORING YOUR DEVICE. https://forum.xda-developers.com/android/help/lenovo-tab-3-8-tb3-850f-unbrick-root-t3598727
There are any number of available procedures to flash these stock partition images to your device. The simplest option is to use a custom recovery like TWRP to flash them. Store these images to your external micro SD (or internal storage if you do not intend to wipe internal storage or format /userdata). In TWRP's main menu, select "WIPE", "ADVANCED WIPE", and select Dalvik Cache, Cache, System, & Data. (For a clean install, it is recommended to format Data as well, by selecting "WIPE", then "Format Data.") Reboot Recovery (often necessary for proper mounting of the data partition). Now, select "INSTALL", then select "INSTALL IMAGE" in the bottom right of the menu, navigate to the storage location of the firmware images, and flash them in any order you choose. If you do not have TWRP installed on your device, XDA Senior Member @Hemphiz has a simple & comprehensive thread here: https://forum.xda-developers.com/android/general/guide-lenovo-tab3-8-tb3-850f-t3559786/page1. In any event, whichever option you choose, please do your homework and research the threads here on XDA relating to your choice. These images may also be installed via fastboot mode. You will need to install Minimal ADB & Fastboot (v1.4 or later) on your PC, ensure the proper Lenovo device drivers & ADB drivers are installed on your PC, and connect your device to your PC via the stock (or quality equivalent) micro USB to USB data sync cable. Once in fastboot mode, open a command prompt in the adb/fastboot directory, and execute the following command lines:
fastboot devices (if you are properly synced, your device serial # will be shown)
fastboot oem fb_mode_set
fastboot flash logo logo.img
fastboot flash boot boot.img
fastboot flash recovery recovery.img (this will overwrite any custom recovery)
fastboot flash system system.img (fastboot will automatically sparsechunk this image)
fastboot erase userdata
fastboot erase cache
fastboot oem fb_mode_clear
fastboot reboot
STOCK PARTITION IMAGES:
The link below provides the following stock firmware images:
/system.........................Size 3.0 GB
/boot..............................Size 16 MB
/recovery........................Size 16 MB
/logo...............................Size 8 MB
Also included in the link are some helpful files like Minimal ADB & Fastboot v1.4.3, the official Lenovo USB Drivers for the TB3-850F (v1.1.21), a general partition index of the tablet, the ADB driver installer for Windows, and the latest PC version of LenovoSuite Mobile Assistant v1.4.1.14199.
I have made a full & complete partition dump of this device, including sensitive firmware partitions such as /oemkeystore, /nvdata, /seccfg, /lk, etc. In the event any members have corrupted these partitions, just request and I will upload these as well. (/nvdata contains device identifiers such as MAC Address, ESN, etc. The device from which these images were taken has since been hardware damaged & salvaged for parts. Therefore, I have no issue with sharing these images. However, as a disclaimer, you are fully responsible for the manner in which you use device ID partitions. Modifying a device's identifiers delves into matters of legality and ethical guidelines, all for which you are solely responsible.)
CREDITS:
Thanks to XDA Senior Member @Hemphiz for his hard work & development on this device, and his thread on TWRP & rooting. Also, huge thanks to @r&xp for his lifesaving tutorial on recovering this device from a soft or hard brick. His guide has revived many devices from the Android cemetery. You guys visiting either of these threads mentioned, be sure and hit the "THANKS" button for their hard work.
DOWNLOAD LINK:
TB3-850F_S100031_171010_ROW
Stock Firmware Partition Images: https://drive.google.com/folderview?id=1vRLwQ2mCD3CwYQZKGHyykDvBd2yGHisT
Sent from my Lenovo Tab 3 8/TB3-850F using XDA Forums Pro Edition.
Hi:
I have a Tab3 8 TB3-850F which bough in China. It's a 2G+16G version.
I have successfully install TWRP and root.
I'm wondering can I install this ROM to my TAB3?
Thanks!
tsaibru said:
Hi:
I have a Tab3 8 TB3-850F which bough in China. It's a 2G+16G version.
I have successfully install TWRP and root.
I'm wondering can I install this ROM to my TAB3?
Thanks!
Click to expand...
Click to collapse
I don't see why you couldn't. But, to clarify some info, what is your Build No and Software Version? Look under Settings, About Device
Build number:
TB3-850F_S100026_161221_PRC
Software version:
TB3-850F-160425
Thank you very much!
tsaibru said:
Build number:
TB3-850F_S100026_161221_PRC
Software version:
TB3-850F-160425
Thank you very much!
Click to expand...
Click to collapse
Based on your Build & Software Version info, I can see no compatibility issues with this Stock ROM & your device. You seem to simply have a Chinese variant of the TB3-850F that is not available for retail in the United States.
In any event, use TWRP to backup all partitions of your tablet before proceeding henceforth with flashing this ROM. Also, do not flash the stock recovery from my link...keep your TWRP fully intact & accessible in case anything goes south as a result of the flash. Accordingly, you should be able to fully restore your partition backups via TWRP in the event my Stock ROM doesn't boot up. But, like I said, I can see no adverse consequences to flashing it. Should you decide to give it a go, please update us on this thread as to the results.
Thank you...
The reason why I would like to flash this ROM is to get full Google service which Chinese Rom does not offer.
Even though I have root and install Google service on it. Some of apps I downloaded from play just won't install.
So I dowbloaded this ROM and flash system-002.img, it works.
Now I have all Google service I needed, and all apps I download are able to install.
But after I reset the tab I've build number S100026_160923_ROW, software version TB3-850F_160412.
It will try to download the update to 161209 but after reboot it just go in TWRP not doing anything.
I'm very satisfied with this, and I will keep searching and wait for a way for me to update to S100030_161209_ROW.
I do really appreciate your work to help me solve my problem and save this tab from goes to trash can.
tsaibru said:
The reason why I would like to flash this ROM is to get full Google service which Chinese Rom does not offer.
Even though I have root and install Google service on it. Some of apps I downloaded from play just won't install.
So I dowbloaded this ROM and flash system-002.img, it works.
Now I have all Google service I needed, and all apps I download are able to install.
But after I reset the tab I've build number S100026_160923_ROW, software version TB3-850F_160412.
It will try to download the update to 161209 but after reboot it just go in TWRP not doing anything.
I'm very satisfied with this, and I will keep searching and wait for a way for me to update to S100030_161209_ROW.
I do really appreciate your work to help me solve my problem and save this tab from goes to trash can.
Click to expand...
Click to collapse
Trying a system update will not work with a custom recovery installed. In spft you can select only to flash the stock recovery then you should be able to update it, when you have done the system update just flash TWRP again.
@MotoJunkie01 I did send you a PM the other day, maybe like for you it did not send or was it my noobishness? :laugh:
stonedpsycho said:
Trying a system update will not work with a custom recovery installed. In spft you can select only to flash the stock recovery then you should be able to update it, when you have done the system update just flash TWRP again.
@MotoJunkie01 I did send you a PM the other day, maybe like for you it did not send or was it my noobishness? :laugh:
Click to expand...
Click to collapse
Try sending another PM please. I could have deleted your PM by mistake.
boot. logo and recovery.img worked but system.img did not .the system.img downloads with the explorer or e symbol not a disc like the others do.don't know if that has anything to do with it not working? need the system.img to work pls.
chico2016 said:
boot. logo and recovery.img worked but system.img did not .the system.img downloads with the explorer or e symbol not a disc like the others do.don't know if that has anything to do with it not working? need the system.img to work pls.
Click to expand...
Click to collapse
Not sure. The /system image is an unmodified dump taken from a brand new TB3-850F. It works for me and other members. Be sure you are running version 1.4 or later on minimal adb & fastboot. That could be your issue.
MotoJunkie01 said:
Not sure. The /system image is an unmodified dump taken from a brand new TB3-850F. It works for me and other members. Be sure you are running version 1.4 or later on minimal adb & fastboot. That could be your issue.
Click to expand...
Click to collapse
ok will try again thank you.
---------- Post added at 01:19 AM ---------- Previous post was at 01:15 AM ----------
is it possible to use the platform tool ,like it says for the twrp for the system image?
chico2016 said:
ok will try again thank you.
---------- Post added at 01:19 AM ---------- Previous post was at 01:15 AM ----------
is it possible to use the platform tool ,like it says for the twrp for the system image?
Click to expand...
Click to collapse
Sure. Minimal ADB & Fastboot is merely a bare essentials utility in contrast to the Android SDK & other platform tools packages. You may also flash the /system image using TWRP.
MotoJunkie01 said:
Sure. Minimal ADB & Fastboot is merely a bare essentials utility in contrast to the Android SDK & other platform tools packages. You may also flash the /system image using TWRP.
Click to expand...
Click to collapse
target reported max download size of 134217728 bytes.
invalid sparse file format at header magi ? Not enough room.
need help with tb3-850f flashing system.img.
Thanks!!! Saved my soft bricked Tab3 8 850F
chico2016 said:
target reported max download size of 134217728 bytes.
invalid sparse file format at header magi ? Not enough room.
need help with tb3-850f flashing system.img.
Click to expand...
Click to collapse
If you use minimal adb & fastboot v1.4, the /system image will automatically be converted into a series of smaller sparsechunk image files, which will be flashed to your device one at a time until complete.
wow dont know what i am doing wrong.
invalid sparse file format at header Magi
erasing 'system'...
okay[0.032s]
sending sparse 'system' 1/21...(129476kb) okay[14.824s] writing 'system'1/21...
failed(remote: uknown chunck type)
finished. total time: 14.904s
need some help adb fastboot file says 'system.img is to long?
wow dont know what i am doing wrong.
invalid sparse file format at header Magi
erasing 'system'...
okay[0.032s]
sending sparse 'system' 1/21...
failed(remote: uknown chunck type)
finished. total time: 14.904s
need some help adb fastboot file says 'system.img is to long?
chico2016 said:
wow dont know what i am doing wrong.
invalid sparse file format at header Magi
erasing 'system'...
okay[0.032s]
sending sparse 'system' 1/21...
failed(remote: uknown chunck type)
finished. total time: 14.904s
need some help adb fastboot file says 'system.img is to long?
Click to expand...
Click to collapse
What version of Minimal ADB & Fastboot are you using?
i am using the 1.4 version adb fastboot from the same link i got the images on this very helpful post
boot img -logo.img-recovery.img say flash on ,and the tablet marks ok that they have flashed---but no luck with the system.img even though i have re downloaded twice same thing .do you have a link that would go through a step by step instalation process you could help me with.
chico2016 said:
i am using the 1.4 version adb fastboot from the same link i got the images on this very helpful post
boot img -logo.img-recovery.img say flash on ,and the tablet marks ok that they have flashed---but no luck with the system.img even though i have re downloaded twice same thing .do you have a link that would go through a step by step instalation process you could help me with.
Click to expand...
Click to collapse
I don't have a tutorial posted per se on installation. Here's a thought. Boot your tablet into TWRP (fastboot boot TWRP.img) and flash my system.img via TWRP. In TWRP main menu select INSTALL, then select the .img file option in bottom right hand corner of screen. (You will need to put the system.img on an ext micro SD)
Here's what I did,
Got new LG G6 (H87110b).
Wanted to upgrade my unit (basically from Nougat to Oreo).
As I am not in AT&T network there was no OTA updates. So I decided to flash kdz.
First I took a full DUMP of the G6 using patched LG UP.
Then followed the guide in here and flashed H87320g_00_OPEN_CA_OP_0809.kdz on H87110b.
Then flashed US99721e_01_0211.kdz on H87320g.
Device worked well at first. But later I experienced certain touch lags (specially after sign in with Google account).
I reset the unit several times, updated all apps, disabled some bloatware apps, but the lag was increased day by day and experienced some heat around finger print scanner.
Later I discovered locking and uncloaking was able to temporally fix lag.
So I enabled Developer Options, then ticked Show touches option. Then I saw five symmetrical touches on my screen (please watch this video). Actually that was the reason to touch lag. Screen was touched by itself!
I guessed this could be a software issue. So I got a H87330b_00_OPEN_CA_OP_0917.kdz file and flashed it on US99721e.
So I got a H87330b Android Pie G6 but with same horrible touch issue. Upgrade wasn't helped me.
Someone please help to figure,
Is this a hardware issue or software issue?
If it is on the software side, will going back to stock H87110b solve this?
Then how can I restore back my DUMP?
Please help! I still LOVE my LG G6! :crying:
I wish @clsA or @runningnak3d will address on this please..
RoboB said:
I wish @clsA or @runningnak3d will address on this please..
Click to expand...
Click to collapse
Good morning, I watched the video and I'm not sure whats going on with the ghost touch. It seems to be in a pattern of some sort so it may be totally normal.
As for returning to stock with the LGUP Dump. Its a matter of fastboot flashing each of the partitions back to the phone one at a time. It is possible to create a ROM that's flashable with TWRP or a batch file to flash in fastboot. I'll try and find something for you to use as a template or a good example.
Alright here's the Back to stock Rom script for the LG V20 20H > https://www.androidfilehost.com/?fid=1322778262904015326
the file is found here in the root of the zip \META-INF\com\google\android\updater-script"
Code:
ui_print("Flashing H910_20h_Oreo_full_stock");
ui_print("Please wait...");
ui_print(" ");
package_extract_file("aboot", "/dev/block/bootdevice/by-name/aboot");
package_extract_file("abootbak", "/dev/block/bootdevice/by-name/abootbak");
package_extract_file("apdp", "/dev/block/bootdevice/by-name/apdp");
package_extract_file("boot", "/dev/block/bootdevice/by-name/boot");
package_extract_file("cmnlib", "/dev/block/bootdevice/by-name/cmnlib");
package_extract_file("cmnlib64", "/dev/block/bootdevice/by-name/cmnlib64");
package_extract_file("cmnlib64bak", "/dev/block/bootdevice/by-name/cmnlib64bak");
package_extract_file("cmnlibbak", "/dev/block/bootdevice/by-name/cmnlibbak");
package_extract_file("devcfg", "/dev/block/bootdevice/by-name/devcfg");
package_extract_file("devcfgbak", "/dev/block/bootdevice/by-name/devcfgbak");
package_extract_file("factory", "/dev/block/bootdevice/by-name/factory");
package_extract_file("hyp", "/dev/block/bootdevice/by-name/hyp");
package_extract_file("hypbak", "/dev/block/bootdevice/by-name/hypbak");
package_extract_file("keymaster", "/dev/block/bootdevice/by-name/keymaster");
package_extract_file("keymasterbak", "/dev/block/bootdevice/by-name/keymasterbak");
package_extract_file("laf", "/dev/block/bootdevice/by-name/laf");
package_extract_file("lafbak", "/dev/block/bootdevice/by-name/lafbak");
package_extract_file("modem", "/dev/block/bootdevice/by-name/modem");
package_extract_file("msadp", "/dev/block/bootdevice/by-name/msadp");
package_extract_file("persist", "/dev/block/bootdevice/by-name/persist");
package_extract_file("pmic", "/dev/block/bootdevice/by-name/pmic");
package_extract_file("pmicbak", "/dev/block/bootdevice/by-name/pmicbak");
package_extract_file("raw_resources", "/dev/block/bootdevice/by-name/raw_resources");
package_extract_file("raw_resourcesbak", "/dev/block/bootdevice/by-name/raw_resourcesbak");
package_extract_file("recovery", "/dev/block/bootdevice/by-name/recovery");
package_extract_file("recoverybak", "/dev/block/bootdevice/by-name/recoverybak");
package_extract_file("rct", "/dev/block/bootdevice/by-name/rct");
package_extract_file("rpm", "/dev/block/bootdevice/by-name/rpm");
package_extract_file("rpmbak", "/dev/block/bootdevice/by-name/rpmbak");
package_extract_file("sec", "/dev/block/bootdevice/by-name/sec");
package_extract_file("tz", "/dev/block/bootdevice/by-name/tz");
package_extract_file("tzbak", "/dev/block/bootdevice/by-name/tzbak");
package_extract_file("xbl", "/dev/block/bootdevice/by-name/xbl");
package_extract_file("xbl2", "/dev/block/bootdevice/by-name/xbl2");
package_extract_file("xbl2bak", "/dev/block/bootdevice/by-name/xbl2bak");
package_extract_file("xblbak", "/dev/block/bootdevice/by-name/xblbak");
ui_print("Now installing system -- please wait...");
package_extract_file("system", "/dev/block/bootdevice/by-name/system");
ui_print("Enjoy The Update");
To restore your modems you need to add this to the above script
Code:
package_extract_file("modem", "/dev/block/bootdevice/by-name/modem");
package_extract_file("modemst1", "/dev/block/bootdevice/by-name/modemst1");
package_extract_file("modemst2", "/dev/block/bootdevice/by-name/modemst2");
package_extract_file("fsg", "/dev/block/bootdevice/by-name/fsg");
Hint: you must use a text editor like Notepad++ if you edit the file.
Hint: it's actually easier to download the above Rom and just replace the files in the zip with yours
Your zip may not contain everything in the above zip. you can edit it as needed.
Ok, I got you. Thanks! But..,
clsA said:
Hint: it's actually easier to download the above Rom and just replace the files in the zip with yours
Your zip may not contain everything in the above zip. you can edit it as needed.
Click to expand...
Click to collapse
Good evening and thank you for your quick reply!
I downloaded H910_20h_Oreo_full_rooted.zip and opened it from 7zip.
There are 42 objects with one folder named META-INF and two .img files named h91020Hpatched_boot.img and v20h_stock_boot.img.
But my G6 DUMP folder has 70 items and no .img files.
So, here's what I'm to do. Please correct me if there's any mistake..
Delete all files in H910_20h_Oreo_full_rooted.zip (except META-INF folder) and copy all 70 files from DUMP in to the zip.
Open \META-INF\com\google\android\updater-script file and edit it as you described.
So there will be 70 lines like package_extract_file("xxxx", "/dev/block/bootdevice/by-name/xxxx"); and some ui_print commands.
Am I correct?
Is editing, updater-script file with Windows Notepad wrong?
What should do to .img files as I don't have any for G6?
RoboB said:
Good evening and thank you for your quick reply!
I downloaded H910_20h_Oreo_full_rooted.zip and opened it from 7zip.
There are 42 objects with one folder named META-INF and two .img files named h91020Hpatched_boot.img and v20h_stock_boot.img.
But my G6 DUMP folder has 70 items and no .img files.
So, here's what I'm to do. Please correct me if there's any mistake..
Delete all files in H910_20h_Oreo_full_rooted.zip (except META-INF folder) and copy all 70 files from DUMP in to the zip.
Open \META-INF\com\google\android\updater-script file and edit it as you described.
So there will be 70 lines like package_extract_file("xxxx", "/dev/block/bootdevice/by-name/xxxx"); and some ui_print commands.
Am I correct?
Is editing, updater-script file with Windows Notepad wrong?
What should do to .img files as I don't have any for G6?
Click to expand...
Click to collapse
you can forget the .img files their not important
what is important is all the files in the code are in the zip
I would first just ad the 42 files plus the 3 modem files to the zip
edit the script to include the modem files and use notepad++ ...windows notepad will not work
@clsA Though I got a flash-able zip, what can I do with a non rooted device?
I searched but couldn't find a way to root H873 one. So I think I should go back to Oreo US997 by flashing US99721e_01_0211.kdz via LG UP and try to root it.
Please let me know if I'm wrong..
RoboB said:
@clsA Though I got a flash-able zip, what can I do with a non rooted device?
I searched but couldn't find a way to root H873 one. So I think I should go back to Oreo US997 by flashing US99721e_01_0211.kdz via LG UP and try to root it.
Please let me know if I'm wrong..
Click to expand...
Click to collapse
If their is still no bootloader unlock for your device your pretty much Done. With an unlocked bootloader you could do the LGUP Dump restore via fastboot
the bad thing about using fastboot is their is no error correction, if you type one letter wrong you could brick you device forever.
That being said, If you still want to restore your backup the above script can be changed into a batch file of sorts.
Take the modem files as an example
Code:
package_extract_file("modem", "/dev/block/bootdevice/by-name/modem");
Becomes >>[COLOR="Blue"] fastboot flash modem modem[/COLOR]
package_extract_file("modemst1", "/dev/block/bootdevice/by-name/modemst1");
Becomes >>[COLOR="Blue"] fastboot flash modemst1 modemst1[/COLOR]
package_extract_file("modemst2", "/dev/block/bootdevice/by-name/modemst2");
Becomes >>[COLOR="Blue"] fastboot flash modemst2 modemst2[/COLOR]
package_extract_file("fsg", "/dev/block/bootdevice/by-name/fsg");
Becomes >>[COLOR="Blue"] fastboot flash fsg fsg[/COLOR]
The final .bat file would look like this
Code:
fastboot flash modem modem
fastboot flash modemst1 modemst1
fastboot flash modemst2 modemst2
fastboot flash fsg fsg
fastboot reboot
you would of course have renamed all the files, removing the _comx from them and copied them to the fastboot folder
If you make your script like this I suggest flashing it one line at a time and note any errors in the command prompt.
fastboot flash system system > could take a vary long time don't get in a hurry and just wait
Hint: Its also worth noting you most likely don't need to flash any file that ends in the letters bak
example laf gets flashed where lafbak doesn't
rpm gets flashed > rpmbak doesn't
this should shorten your list considerably
Code:
PS C:\platform-tools> fastboot flash aboot aboot target reported max download size of 536870912 bytes
sending 'aboot' (2048 KB)...
OKAY [ 0.094s]
writing 'aboot'...
FAILED (remote: device is locked. Cannot flash images)
finished. total time: 0.109s
@clsA And not supported by LG Developer - Unlock Bootloader at https://developer.lge.com/
RoboB said:
@clsA And not supported by LG Developer - Unlock Bootloader at https://developer.lge.com/
Click to expand...
Click to collapse
Yeah that's basically why I stuck with the V20 and it was my last LG
Sent from my ONEPLUS A6010 using Tapatalk
@clsA That means I have to live with this ghost touches? Oh! how sad..
BTW isn't there any way to make kdz file from DUMP?
Hey folks,
I have rooted (magisk) OnePlus 8 phone with Android 11, w/o TWRP recovery. I'm trying to replace kernel with one of blue_spark, here's what I'm doing
1. Download zip file from https://github.com/engstk/op8/releases/tag/r112
2. Extract and unpack Image.gz
3. Unpack Magisk patched boot.img to /tmp (magiskboot unpack boot.img)
4. Replace kernel with unpacked Image (cp Image /tmp/kernel)
5. Repack boot.img (magiskboot repack boot.img boot-new.img)
6. Boot with boot-new.img (fastboot boot boot-new.img)
And here is when I'm getting into "QUALCOMM CrashDump Mode"
The same result if I build kernel from sources. Repacking boot.img with original kernel works, so problem is unlikely in magiskboot.
I'm trying to figure out the problem, but without kernel logs it's troublesome. Any ideas?
Thanks.
Hm... It looks like, I also have to update DTB. After that device boots successfully. Seems a bit strange to me. What's the difference in supported devices between blu_spark and stock kernel?
Ok, turned out AVB was enabled in the original device tree:
fsmgr_flags = "wait,slotselect,avb";
Switching it off fixes boot process.
This process is very time consuming and tedious, you will need to use both windows and linux for this process and you will need to have patience as well as general information from Hovatek.
YES your bootloader MUST be unlocked first.
you need need to download RD tool app and stock oem firmware for the device.
extract the vbmeta-sign.img then extract your vbmeta-keys with extractor and place all keys in 'keys' folder.
patch oem boot.img with magisk and unpack it with android image kitchen, and repack, this will generate a smaller boot.img that is normal.
use avbtool command python avbtool add_hash_footer to sign and inflate your small patched boot.img to normal size.
use avbtool command python avbtool make_vbmeta_image to generate your custom-signed-vbmeta.img file will only be 16kb that is normal.
use vbmeta_pad.py command to inflate custom-signed-vbmeta.img file back to 1024kb stock size.
Once you have generated all your modified files its time to flash via RD tools
load the stock oem .pac firmware and under settings only select FDL1 and 2 , vbmeta and boot. double click to look for your custom vbmeta and boot-patched.img and flash it.
You will most likely be in a non booting state with only a quick boot logo flash then a black screen.
Now close RD tools and reload it again and this time select FDL1 and 2, and select your stock oem vbmeta-sign.img only and flash.
you will boot into android with magisk root.
If you flash custom files and fails to boot after flashing stock oem vbmeta-sign then flash all stock oem files to return to a factory state and retrace any errors or missed steps. read and re-read all steps to get a better understanding and double and triple check linux commands.
AVB_tools
avbtools.7z
drive.google.com
I have a alldocube smile 1 (t803), but I have no ability to do all the repacking of root.img. However, rooting is necessary to install the tool such as XX-net. Will you send me the two magisked images and the tool to flash them back. Thank you. My gmail: wu.gt.kent