I've decided I need a tablet, after week of hair ripping and hitting wall with my head, I've selected the least shitty device I was able to find for a reasonable price (below 200$), the Lenovo M8 FHD. And as with every Android device I ever had, I decided to root it immediately after a first boot (to verify it's working at all).
I'm surprised by the state of the market of the tablets (or any consumer electronic), these devices are mostly pieces of shit. I wanted 8 inch screen with decent resolution and reasonable amount of RAM. In the Czech Republic only 3 reasonable android manufacturers are selling tablets - Samsung, Lenovo and Huawei, and their devices are all the same, almost everything is a 10 inch beast, everything looks like that Apple tablet, all cheaper device have only 2 GB of RAM and all 8 inch devices were released around 2 years ago (this might be a result of Corona lockdowns). Try to find (in 2021) 8 inch tablet with USB-C, over 2 GB RAM, stereo speakers, decent screen and a root guide on xda below 200 USD, that's close to impossible.
I gave up looking for tablet with LineageOS or other alternative ROM port, decided I can live with micro USB (in 2021!) and selected the Lenovo M8 FHD (I hate what they did to ThinkPads, but I was really desperate after week of browsing tablet reviews). I was considering the Huawei T10s, but it's 10 inch and there were some issues with rooting mentioned on XDA, so I didn't want to risk it.
A rooted Dndroid device gives you a true freedom. You can get rid of all these stupid preinstalled apps, google spyware, install a system wide adblocker and mess with your devices with many ways. But as always, the great power comes with a great responsibility. It's very easy to brick your device, get it full of viruses,... So proceed with caution, I can take no responsibility if you brick it. As long as you can access the fastboot it should be possible to recover the device if you mess things up, but there's always risk of creating an expensive paperweight from your shiny new device.
System->About tablet and tap on the Build number until developer mode is enabledDeveloper options and enable USB debugging and OEM unlockadb installed, run adb devices, you should see your device listed (the tablet will show popup you need to accept for adb to connect)adb reboot fastboot to enter fastboot modefastboot flashing unlock and follow instructions on tablet (press volume up to confirm) - this will factory reset the device!fastboot rebootOrange mode message shown in the initial screenUSB debugging againNow we need to get the boot image from the stock rom. Download Lenovo rescue and smart assistant tool (windows only unfortunately), install it and login using your Lenovo account (oh, come on, why do I need to create account everywhere?). Now under rescue tab, click Rescue Now and select tab Power off mode, select your device (according to label on back of your tablet) and download the stock rom image.
Extract the archive and copy boot.img to your device. We'll use the Magisk tool to path the boot.img to add root capabilities. Download the latest release apk and install it on the tablet. In Magisk, click Install and select the boot.img you copied there. The Magisk will patch the file with root support. Copy the patched file back to PC (oh my, why there's no PC version? The android could be skipped here...).
Now we can flash the patched boot image (all flash steps are dangerous and can potentially brick the device!):
adb reboot fastbootfastboot flash vbmeta --disable-verification vbmeta.img - disable Android Verified Boot to allow flashing the modified boot imagefastboot flash boot magisk_patched.img - flash the imagefastboot rebootYes, such things can happen when messing with android firmware, you can get a bootloop, etc. But as we have the stock firmware, this can be easily fixed. First you have to enter the fastboot mode - power off your device and the hold power button and volume down together, once the Lenovo logo is show, you can release the buttons and the tablet will boot into the fastboot mode.
In fastboot mode, you can flash any partition you messed up by running fastboot flash <parittion_name> <image>.img.
The primary reason I root my devices is the ability to remove all the spy and bloatware present in the device. To get rid of google, first install the F-Droid alternative app store and install some keyboard as the stock keyboard is tied to google apps. Add debloater, busybox and microG modules to magisk, install terminal emulator and run su followed by debloat. Now you can select apps you want to remove, be careful not to remove anything vital, else it will break the installation and you'll need to do a factory reset. List of my removed apps:
1 - FSKAREN
2 - CtsShimPrebuilt
3 - Wood
4 - Drive
5 - Google Play Movies
6 - Gmail
7 - Main components
8 - FaceLock
9 - YouTube
10 - YouTube Music
11 - Calendar
12 - Keep Notes
13 - Chrome
14 - Maps
15 - Gboard
16 - Google Location History
17 - Photos
18 - Google Contacts Sync
19 - Google Text-to-speech Engine
20 - Duo
21 - Google Play Store
22 - Digital Wellbeing
23 - Assistant
24 - Device setup
25 - Google Partner Setup
26 - Google
27 - Market Feedback Agent
28 - Android Setup
29 - Google One Time Init
30 - Google Services Framework
31 - System Update
32 - Multi-user
33 - Multi-User
34 - Tips
35 - Lenovo Levision
36 - Files
37 - Tags
38 - ScreenAssistant
39 - Screen Recorder
40 - Lenovo ID
41 - Lenovo Feature Update