yashsingh1/xdaforums huggingface dataset:
[Android Q&A, Help & Troubleshooting] Isrgish:
What do you mean it updated to Android 10?

---------- Post added at 07:24 PM ---------- Previous post was at 06:58 PM ----------

I downloaded the Android 10 update and flashed it to my device.

Now I patched the new boot.img and flashed to my device. But now I get stuck in a boot loop.

Do I need to do something more then just patch the boot.img?

How did you update to Android 10?
[Android Q&A, Help & Troubleshooting] jamestx10:
I updated to Android 10 via the rescue and smart assistance PC app. Cannot get root. I patch the boot.img in Magisk and then flash it and get a boot loop. Any ideas?
[Android Q&A, Help & Troubleshooting] Isrgish:
I'm having the same problem.

I was told to use the Canary version of Magsik Manager but I haven't had any better results there.

See Lenovo tab M8 bootloop after patching Android 10 #3479

Yo can download the Magisk Manager for Canary Here (Scroll down to Downloads)
[Android Q&A, Help & Troubleshooting] jamestx10:
I found an answer that worked on another Lenovo so I tried it on mine and I am rooted with Android 10 now.

After flashing the patched boot image but before you reboot you need to also flash the vbmeta.img from the full firmware using this command:

fastboot --disable-verification flash vbmeta vbmeta.img

then

fastboot reboot

System loaded up and I have root.
[Android Q&A, Help & Troubleshooting] Isrgish:
Is your device come from China and flash global ROM?

Mine is and your solution didn't help. After flashing the vbmeta.img file with the option --disable-verification, I'm able to boot into my device, But my device isn't rooted.

Which version of Magisk Manager did you use?
[Android Q&A, Help & Troubleshooting] jamestx10:
Mine has US on the box. TB-8505FS

Software version: TB-8505FS_RF01_201015

Build: TB-8505FS_S300025_201015_BMP

Magisk Manager: Stable 8.0.3 (314)(14)

Magisk: Stable 20.4 (20400)
[Android Q&A, Help & Troubleshooting] Isrgish:
I think that is the difference. Can you give me your patched boot file I would like to try it on my device.

When I try to patch with version 8.0.3 my patched file is way smaller then the original boot.img.

Thank You,
[Android Q&A, Help & Troubleshooting] jamestx10:
Mine is much smaller as well.
[Android Q&A, Help & Troubleshooting] drumst1x:
I just picked up a couple of these for the kids. I have the TB-8505FS (S/N HA159TTN (66) (apparently there is a 65 and a 66 hardware revision))

First I installed LMSA (Lenovo Rescue & Smart Assistant, no idea why the letters don't match the initialism) and installed the latest recovery files, which bumped me from the stock Android 9 up to Android 10. The .zip file that installed was flashed TB_8505FS_S300025_201015_BMP

Next I installed the Canary magisk manager from github on the tablet

Copied the stock Android 10 boot.img from Lenovo over to the tablet's download folder

patched that boot.img in Magisk Manager (33.6 MB boot.img created a 33.6 MB magisk_patched.img)

ADB Rebooted (from W10) into Fastboot

Unable to detect device from Fastboot.

Moved over to my Mac. Tablet still in Fastboot. Downloaded Fastboot/ADB from Google for the mac.

Mac detected the tablet with `./fastboot devices`

`./fastboot flashing unlock` (successful)

`./fastboot reboot` (successful)

On the loading splash screen, I now get the Orange alert that the device is unlocked.

Device boots up normally.

Reboot into fastboot

Flashed the magisk patched boot.img

fastboot reboot

Bootloops (see the orange alert with the Lenovo logo for about 8 seconds, then screen black, then repeat, ad infinitum)

Rebooted to fastboot

Reflashed magisk boot and also tried flashing vbmeta (as was suggested earlier)

Same bootloops as before

I was able to reflash just the stock boot.img from fastboot successfully, so I'm out of the bootloops, but I wasn't able to achieve root since I never was successful at flashing the magisk-patched boot.img.

Any other ideas?
[Android Q&A, Help & Troubleshooting] Isrgish:
I just realized that your device is 8505 while mine is 8705 so I can't use your boot.img.

---------- Post added at 06:43 PM ---------- Previous post was at 06:40 PM ----------

I'm having the same problem the only difference is that once I flash the vbmeta.img with --disable-verification I'm able to boot without a bootloop but I don't have root.
[Android Q&A, Help & Troubleshooting] drumst1x:
Ahhhhhhh ok, I just realized I may have forgotten to do the --disable-verification flag when I flashed VBMeta.. so maybe I should re-try that again. I may also try to re-patch my boot.img from Magisk again, to see if it gives me a differently-sized patched image.

Will post back later with results.... Thanks for the (possibly inadvertent) reminder.

If anyone else has any thoughts, please give a shout. Also, if anyone knows if there's a way to get some sort of log that is created by these bootloops (so maybe I could see what is causing it, or at least get guidance), LMK.... a logcat or something? I just have no idea how i'd get it if all I can do when it's looping is get into Fastboot.....

**edit** Ok - so I just tried flashing vbmeta with the --disable-verification flag. Now i CAN boot. But when I'm in Magisk Manager, it shows as if I have no Magisk installed whatsoever (even though i DID flash the patched_magisk.img first). So for some reason the vbmeta flash undoes whatever flashing the boot did (at least with respect to Magisk being installed).

I've read in some other threads about other devices needing an "empty" vbmeta flashed in order to work correctly. Wondering if that's an avenue we need to pursue? I don't even have the slightest idea what the vbmeta file even is (I've never seen it before nor needed to flash it on any of my other devices), so I wouldn't have any idea on how to begin investigating "making" a flashable vbmeta that may help us... but does this sound like a viable route forward on this device?
[Android Q&A, Help & Troubleshooting] Isrgish:
I'm in the same boat as you I can't get root and when flashing the vbmeta.img I find I'm not rooted.

I'm wondering if there is rather a problem with the way Magisk is patching the file. I don't see how vbmeta can revert the boot.img back to the original.

About the logs you can take a look Here . There is info on getting logs. I'm not familiar with these logs and don't have the time to study this at this time.
[Android Q&A, Help & Troubleshooting] Isrgish:
I finally figured this out and got root. You need to flash the patched boot image file after you flash the vbmeta.img with --disable-verification.

Here are the steps I did to get root.

1. Copied boot.img from the firmware to my device.

2. Downloaded Magisk Manager. (The regular version, no need for the canary version).

3. Patched the boot.img with magisk manager.

1. Clicked on "Install" on the righthand top in magisk manager.

2. Clicked on "Next" Righthand top.

3. Selected "Select and Patch a File".

4. picked the boot.img file I had copied in step 1. Magisk manager patched the file.

4. Copied the patched file pack to my PC.

5. Booted into Fastboot.

6. (Flashed the patched boot image to my device "fastboot flash boot path-to-patched-boot-image") I don't think this is needed here but it is what I had done.

7. Flashed the vbmeta.img from the firmware with the option --disable-verification. "fastboot --disable-verification flash vbmeta path-to-vbmeta-image" It does not need to be an empty vbmeta image.

8. Flashed the patched boot image to my device "fastboot flash boot path-to-patched-boot-image". (A second time, but as mention before I don't think the first time is necessary).

9. fastboot reboot.

...And now I have root.

Disclaimer use this info at your own risk. I take no responsibility for it.

This is copied from this answer on Android Enthusiasts Give thanks where it is rightly earned.
[Android Q&A, Help & Troubleshooting] manples:
it worked for me, thanks man !
[Android Q&A, Help & Troubleshooting] duremars:
First u need to know if there are developers for ur device only then u will get support for everything

First u need to have a custom recovery like twrp if there is a developer available. Then download the rom that u want again if there is developer available. Just in case there are non eu can try to learn and port recovery and rom to ur device …. If u can . Moreover samsung had a crappy OS previously but after one ji I think he stock rom in itself is good . ….. so why do u want a custom rom anyways with all the battery drain camera and bug issues that accompany the custom rom .
[Android Q&A, Help & Troubleshooting] Isrgish:
I finally figured out how to port a TWRP for this device.

This is for the Lenovo tab M8 FHD TB-8705F running the following version TB_8705F_S300022_201015_BMP

Please find the file attached here.

To make this work you will need to flash the vbmeta.img with the option --disable-verification. Some say you need the vbmeta.img to be an empty image file I'm attaching such a file here as well.

Use this at your own peril.

If you would like to try your hand at porting it yourself I used This guide. It was very helpful.
[Android Q&A, Help & Troubleshooting] drumst1x:
Thank you @Isrgish for posting this. I finally got around to trying it again. For posterity, and for anyone with the same device, here are the exact steps I followed (I had 2 of them, so I wrote these down as I was doing the second one).

My Device: Lenovo Smart Tab M8 8505FS (S/N HA159TTN (66)

First I installed LMSA (the application is called "Lenovo Rescue & Smart Assistant", but the tool used to be known as Lenovo Moto Smart Assistant) and installed the latest recovery files, which bumped me from the stock Android 9 up to Android 10. The .zip file that installed was flashed TB_8505FS_S300025_201015_BMP. Note: the restart after the install appears to hang on the (non-animated) LENOVO logo for a while. Just be patient, you'll eventually boot back up into the initial setup.

Have platform-tools installed for adb / fastboot

Steps in immediately next post (I hit my 2000 character limit :) )
[Android Q&A, Help & Troubleshooting] drumst1x:
I performed these on a mac, I wasn't able to get fastboot to detect the tablet on my windows 10 machine; I didn't test my linux machines):

Fully charge tablet

Turn tablet on

Skip as much of the initial setup process as possible, however you MUST be connected to the WiFi in order to allow unlocking of your bootloader (Start -> More/Accept -> no wifi/Set-Up Offline -> skip setting current time set -> Choose reporting options / Hit Accept -> Skip Pin -> Skip Lenovo ID -> Lenovo User Experience Program (choose if you want to skip or not) -> Choose navigation etc) Get to the home screen

Swipe down from top of screen and open Settings

Developer Tools (enable dev tools if you don't yet have access) -> Enable USB Debugging

Developer Tools -> Enable OEM Unlocking (again, if you're not on WiFi, it may not allow you to do this)

Connect tablet usb and usb to computer (Click "allow" when the usb debugging popup comes up)

./adb devices (Make sure the computer can see the tablet)

./adb reboot bootloader

./fastboot devices (Make sure the computer can see the tablet)

./fastboot flashing unlock then press volume-up on the device

./fastboot reboot

On the Lenovo loading splash screen, you should now get the Orange State alert that the device is unlocked. It may take a bit to reboot as you've just wiped all data again and it must do initial setup

Device boots up normally. Now you can do real setup steps if you like, or you can ignore everything like in Step 3 above.
[Android Q&A, Help & Troubleshooting] drumst1x:
Pretend like this "1" starts at "15" from the previous post.... damn 2000 char limit....

Enable USB Debugging again (Step 4-5)

Grab the boot.img and vbmeta.img from the LMSA TB_8505FS_S300025_201015_BMP update. Copy the boot.img to the tablet, taking note of the location (e.g., ./adb push boot.img /sdcard/)

Install latest version of Magisk Manager (doesn't need to be the Canary version, can be the regular version) and patch the boot image.

Clicked on "Install" on the righthand top in magisk manager

Clicked on "Next" Righthand top.

Selected "Select and Patch a File".

picked the boot.img file I had copied in step 1. Take note of the location of the patched image (magisk_patched.img), and copy it to your PC.

Reboot into bootloader again (./adb reboot bootloader)

Flash the magisk patched boot.img ./fastboot flash boot path/to/magisk_patched.img

Flash the VB meta with the disable-verification flag ./fastboot --disable-verification flash vbmeta path/to/vbmeta.img

Flashed the magisk patched boot.img AGAIN!!!!!! (this part is key, otherwise you'll bootloop) ./fastboot flash boot path/to/magisk_patched.img

Reboot, you should now be rooted (can confirm in Magisk Manager) ./fastboot reboot

This will have you in a rooted, unlocked bootloader status. I have NOT yet tried the steps from the FHD version of the tab to see if I can get TWRP running. But this is a start. :)
[Android Q&A, Help & Troubleshooting] metalblaster:
Thanks mate. Think I am going to try building a Rom for this device when I get some free time. ASOP or Lineage would be great on it.
[Android Q&A, Help & Troubleshooting] LenovoM8FHD:
Thanks friend, I installed your TWRP port - works great.
[Android Q&A, Help & Troubleshooting] metalblaster:
Tried your TWRP and got stuck in a boot loop. Then realized I was on the 8505f not the 8705f heh. Ill get an 8505f image up here in a moment. Good effort btw.
[Android Q&A, Help & Troubleshooting] retro5:
I have an 8505 too. Did you get your version of TWRP to work. Could you share it.

Thanks!
[Android Q&A, Help & Troubleshooting] retro5:
I've been unhappy with the android 10 update and hoped to fix some of the problems with root, but the above procedure didn't work.

After some searching, I found the original firmware and downloaded it. With Rescue installed, I let it download the new firmware. I renamed the download folder name and unzipped the old firmware into a folder with the same name as the new firmware.

I ran a rescue and it flashed android 9 back to my M8.

I enabled developers mode and turned off auto update.

It does see some updates to 9, so I will install them, but so far, so good.
[Android Q&A, Help & Troubleshooting] betacrypt:
What fastboot drivers did you all use to get your device detected? I've tried numerous ones and my device just isn't getting regonized when I run fastboot commands. My other android devices are recognized just fine. Using Windows to unlock a TB-8505F.
[Android Q&A, Help & Troubleshooting] retro5:
I had the same problem with not seeing the device in fastboot. When you install the Lenovo Rescue app, it has it's own drivers and does the flashing for you. I have been considering putting a Magisk modified boot.img in the firmware folder and then let Rescue flash to see if I can get root. But for now, I'm just happy to be back on Android 9.
[Android Q&A, Help & Troubleshooting] retro5:
The driver thing is really odd. The Rescue app sees the device and I downloaded the All In One tool from this forum and it sees the device in fastboot, but when I'm in adb, no luck.

The All In One tools has a button that opens a cmd window and it works to run adb cmds. I used that numerous times flashing the modified boot.img and couldn't get root. I could have used that to flash the android 9 rom but decided to try Rescue with the folder change and it is really quick and easy.
[Android Q&A, Help & Troubleshooting] lockekey:
I managed to root this device today after a couple attempts.

Could you repost your ported TWRP for this device?

I don't see the file (I see the image-new.zip - assuming this is the empty vbmeta, and the vbmeta_disbled,zip-very helpful, thank you, got me past bootloop and rooted).
[Android Q&A, Help & Troubleshooting] lazyboi305:
Hi. I'm very interested in rooting and possibly flash a custom rom on my new TB-8505F. Can anyone confirm any custom roms available? Or, is there beneficial features into rooting even without roms?

Thanks!
[Android Q&A, Help & Troubleshooting] numbazZ:
Just got the tab yesterday 8505F model, updated to android 10 and I have issues with notifications, sometimes there are no notifications at all and sometimes some of them pop up only when I activate the screen. I need to manually check the messaging apps to see if i have some new messages or activities. If there are no solutions to that, I will return the tab back
[Android Q&A, Help & Troubleshooting] retro5:
There are tons of complaints on the Lenovo forum, not just for the M8 but also the M10 and Yogas. In addition to the widgets not updating , I was having other glitchy issues that were driving me crazy. Finally just rolled it back to 9 and it's been rock solid since.

I really like the ambient mode and assistant built in.

Funny thing, I have some smart bulbs I have been managing with Ghome. When I went back to 9, I tried ambient mode before reinstalling all my apps. Without Ghome or any other management app for my bulbs installed, the buttons for the bulbs still showed up in ambient mode and work! They are single buttons, one touch off, another touch on and the icon changes to reflect if on or off. No app has shortcuts like that. Yes, there are shortcuts in Ghome but very convoluted and require one for each action and open assistant full screen to work. Can't figure out how ambient mode can create a simple useful shortcut that Ghome can't. Guess google people don't talk to each other.
[Android Q&A, Help & Troubleshooting] codyw1996:
Hi, this bootlooped my 8505FS. Not sure if it's different.

I unlocked the bootloader, it's in orange state.

I couldn't figure out how to update the device in the Lenovo Smart Assistant Software.

I clicked on the rescue button and it downloaded "TB_8505FS_S300025_201015_BMP.zip"

I DID NOT perform the rescue, instead I just patched the downloaded boot.img in Magisk.

The original boot image is 32MB, but the patched boot image is only 10.1MB. Is this right??

I went ahead and flashed magisk_patched.img, then vbmeta, then magisk_patched again, and yeah it's bootlooping now.

I tried restoring the downloaded unpatched boot.img and it's still bootlooping.

I bricked my device.

I think I should have performed the rescue first to update everything???

I think the boot image I extracted is for a newer rom version.

I can still get into fastboot, how should I proceed. I've tried flashing vbmeta again. Should I try to flash the new system.img?? Can I flash all the images over fastboot?
[Android Q&A, Help & Troubleshooting] codyw1996:
I tried to flash system, cache, and recovery over fastboot.

Still bootlooping.

I'm not sure how to flash some of these images that are in the zip file over fastboot, for instance "lenovocust.img".

UPDATE MEGA-BRICKED!!

I found a file in the zip called checksum.ini which holds all the partition names.

lenovocust.img matches to "lenovocust"

logo-verified.bin matches to "logo"

dtbo-verified.img matches to "dtbo"

etc..

So I tried flashing a few more images over fastboot and now the device won't boot at all.

Kind of a comedy of errors really.

I think where I went wrong is that I left the disable verification flag set when I flashed alll the images.

From brand new to bricked in 7 hours.

I threw away the box but kept the receipt, hopefully Walmart will let me exchange it or get a refund, sigh.
[Android Q&A, Help & Troubleshooting] retro5:
All you have to do is run rescue and it will fix it. I bricked mine several times and rescue was a quick and easy fix.

I think the mistake I made was when in fastboot, I would unlock the bootloader then flash. Instead, I unlocked the bootloader, booted into the os and re-setup dev options, enabled usb debugging, and usb to file transfer and turned off auto update. I also realized that the unlock wiped Magisk, so In reinstalled it. I didn't setup anything else or even turn on wifi. Then I reconnected to my pc and 1st flashed the disable verification then the patched rom. Then when I rebooted, it was rooted.

I am still using 9 because of all the problems with 10, so maybe 9 is easier to root, but it is rock solid.

I got mine from Walmart on black friday, so we have the same mode.

Don't give up, it's a really nice device, worth getting it to work. I would have stayed with unrooted stock until they forced 10 on it and it was next to unusable.
[Android Q&A, Help & Troubleshooting] retro5:
By the way, I don't think you should be flashing anything except the patched image and the disable verification. Flashing recovery bricked mine one time too.
[Android Q&A, Help & Troubleshooting] codyw1996:
I can't get into fastboot anymore. The only sign of life is the red power led when I plug in a USB cable.

Is recovery going to work at that point? I didn't try.
[Android Q&A, Help & Troubleshooting] codyw1996:
Oh wait nevermind. I rescued it. I didn't see the Power-off rescue method.

Thank you, buddy.

Also I think I know why the rooting process didn't work for me before.

I didn't wait for the Lenovo Rescue Software to actually verify and decompress the downloaded image. (It does it automatically, you have to wait for it) I think I flashed a bunch of partially decompressed, corrupted images.

edit:

All right, i'm rooted on Android 10.

Wow, you weren't kidding about these Android 10 issues.

It's chugging! Super choppy animations.

Even setting the scheduler to performance, and disabling all unecessary apps doesn't help much.
[Android Q&A, Help & Troubleshooting] Zero_Shadow:
I was able to root thanks to the instructions above for Android 10 really appreciate the share.
[Android Q&A, Help & Troubleshooting] numbazZ:
I'm trying to port TWRP for 8505F, but it asks me a password to decrypt data, even if I have no password lock on Android

So. Works well after I performed a Format Data, flashed Magisk zip and DM Verity force encryption disabler. Here is what I did. If you don't want to lose all your data, don't do this.

Works with Android 10, for 9 it only flashes with SP Flash Tool swapping the stock recovery to this one

1. You need to have an external SD card to put files in, MTP does not work for now for some reason. Also, enable USB debugging obviously

2. Download Magisk zip from HERE and DM verity & force encryption disabler zip from HERE and put them inside your external SD card.

3. Reboot to bootloader ./adb reboot bootloader

4. Flash a recovery ./fastboot flash recovery twrp8505f.img

5. Reboot to recovery ./fastboot reboot recovery

6. In recovery when it asks for password press Cancel and go to Wipe - Format Data, type yes.

7. Now reboot to recovery again, go to Install, select Magisk zip, flash it, then go back to Install and flash DM verity disabler

Now everything should be fine, you can reboot to system and back to recovery without problems

This is my first attempt to port a recovery image, I wouldn't mind if someone will help me to figure out why MTP isn't working and maybe something else will appear
[Android Q&A, Help & Troubleshooting] GBAFan:
I was told I might want to check here about 8705F firmware, specifically the Android 9 version. Android 10 has hobbled my tablet, and unfortunately the tablet came shipped with 10 only so I can not do rollback. I have had no real luck finding firmware from sites that are not paywalled, and have had even less luck getting the two firmware files I found online to flash at all. Any help with this would be greatly appreciated!
[Android Q&A, Help & Troubleshooting] numbazZ:
I found this site, successfully downloaded firmware for 8505, here is for 8705, the older one probably android 9 https://mirrors.lolinet.com/firmware/lenovo/Tab_M8_FHD/TB-8705F/

Here is the explanation of how to roll back to android 9, but on Russian. Hope you can read it, or use google translate, maybe you can do something about it https://4pda.ru/forum/index.php?showtopic=985366&st=400#entry102463006
[Android Q&A, Help & Troubleshooting] GBAFan:
Thanks for the link, but one of the links on the page itself was a 404, so it seems a like a dead end for now. Also tried it with Lenovo Recovery Assistant as a test, and no luck there either. Bummer, but I appreciate the help!