Lenovo tab m8

[drumst1x]

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.

....
....

This is copied from this answer on Android Enthusiasts Give thanks where it is rightly earned.

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 )

 

[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):

1. Fully charge tablet
2. Turn tablet on
3. 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
4. Swipe down from top of screen and open Settings
5. Developer Tools (enable dev tools if you don't yet have access) -> Enable USB Debugging
6. Developer Tools -> Enable OEM Unlocking (again, if you're not on WiFi, it may not allow you to do this)
7. Connect tablet usb and usb to computer (Click "allow" when the usb debugging popup comes up)
8. ./adb devices (Make sure the computer can see the tablet)
9. ./adb reboot bootloader
10. ./fastboot devices (Make sure the computer can see the tablet)
11. ./fastboot flashing unlock then press volume-up on the device
12. ./fastboot reboot`
13. 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
14. Device boots up normally. Now you can do real setup steps if you like, or you can ignore everything like in Step 3 above.

 

[drumst1x]

Pretend like this "1" starts at "15" from the previous post.... damn 2000 char limit....

1. Enable USB Debugging again (Step 4-5)
2. 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/)
3. Install latest version of Magisk Manager (doesn't need to be the Canary version, can be the regular version) and patch the boot image.
   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. Take note of the location of the patched image (magisk_patched.img), and copy it to your PC.
4. Reboot into bootloader again (./adb reboot bootloader)
5. Flashed the magisk patched boot.img ./fastboot flash boot path/to/magisk_patched.img
6. Flash the VB meta with the disable-verification flag ./fastboot --disable-verification flash vbmeta path/to/vbmeta.img
7. Flashed the magisk patched boot.img AGAIN!!!!!! (this part is key, otherwise you'll bootloop) ./fastboot flash boot path/to/magisk_patched.img
8. 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.

 

[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.

 

[LenovoM8FHD]

Thanks friend, I installed your TWRP port - works great.

 

[metalblaster]

Thanks friend, I installed your TWRP port - works great.

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.

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.

 

[retro5]

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.

I have an 8505 too. Did you get your version of TWRP to work. Could you share it.
Thanks!

 

[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.

 

[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.

 

[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.

 

[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.

 

[lockekey]

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.

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).

 

[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!

 

[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

 

[retro5]

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

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.

 

[codyw1996]

Pretend like this "1" starts at "15" from the previous post.... damn 2000 char limit....

1. Enable USB Debugging again (Step 4-5)
2. 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/)
3. Install latest version of Magisk Manager (doesn't need to be the Canary version, can be the regular version) and patch the boot image.
   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. Take note of the location of the patched image (magisk_patched.img), and copy it to your PC.
4. Reboot into bootloader again (./adb reboot bootloader)
5. Flashed the magisk patched boot.img ./fastboot flash boot path/to/magisk_patched.img
6. Flash the VB meta with the disable-verification flag ./fastboot --disable-verification flash vbmeta path/to/vbmeta.img
7. Flashed the magisk patched boot.img AGAIN!!!!!! (this part is key, otherwise you'll bootloop) ./fastboot flash boot path/to/magisk_patched.img
8. 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.

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?

 

[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.

 

[retro5]

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.

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.

 

[retro5]

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.

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.

 

[codyw1996]

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.

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.