[Miscellaneous Android Development] Treeoctopus:
Hello all,

So, after typing that I brought myself into a state where I'm powering up to fastboot and Android never loads.

Not overly worried since it seems like SP flashing tools are pretty good at resetting machines, but now I'm stuck in a fight getting the accursed drivers to work on a win10 computer to get the flashing to work.

Ultimately I think I flashed the wrong vbmeta files (step 10 below) - just used a single one sitting in the directory ( I think from the XL Lineage OS thread) and didn't actually do the unzip of the three vbmeta files until later. (24)

Here's the worklog:

The goal is rooted stock by installing Magisk via recovery

1) Activate developer settings, USB debugging, bootlock unloading

2) terminal: adb reboot bootloader

3) terminal " fastboot flashing unlock" (I couldnt get "fastboot OEM unlock" to work as per the original post, but this one worked)

4) confirm on screen to unlock bootloader

5) powered down with r side button and it rebooted, showed warning message about unlocked bootloader and then booted to factory-fresh install

6) downloaded atom XL TWRP from https://github.com/ADeadTrousers/android_device_Unihertz_Atom_XL/releases

v20201110-alpha - I had downloaded this one earlier and saw the recovery.img there.

(Thank you ADeadTrousers, much appreciated)

7) Went back to settings, unlocked developer settings, turned USB debugging back on

8) terminal: `adb reboot bootloader`

9) terminal: fastboot flash --disable-verification --disable-verity vbmeta vbmeta.img

10) Couldn't find the files for these steps `fastboot flash --disable-verification --disable-verity vbmeta_system vbmeta_system.img`or . Run `fastboot flash --disable-verification --disable-verity vbmeta_vendor vbmeta_vendor.img`

) So I took the plunge:

11) terminal: fastboot flash recovery recovery.img

12) terminal: fastboot reboot recovery

13) Goes to unihertz splash screen, then Lineage Recovery!

14) Put Magisk-v20.2.zip (downloaded from official site) onto phone via Apply Update - ADB sideload

15) adb sideload Magisk-v20.2.zip

16) Magisk installer text displays on screen

17) Reboot from Lineage Recovery - it went to fastboot mode, maybe I pressed the wrong selection ...

18) ten seconds holding down power button restarted back to fastboot mode... uhoh!

19) can't get terminal:adb devices to recognize the phone

20) back to lineage recovery with Power button + up button (phew!)

21) Rebooted from Lineage Recovery - goes to splash screen, and then again to fastboot mode.

22) Back to recovery, adb devices shows device again.

23) Went back and read the original post again (yeah... stupid me) and pulled down the correct vbmeta.zip file

24) did the triplet of commands via lineage Recovery fastboot as I should have done.

a) fastboot flash --disable-verification --disable-verity vbmeta vbmeta.img

b)fastboot flash --disable-verification --disable-verity vbmeta_system vbmeta_system.img

c) fastboot flash --disable-verification --disable-verity vbmeta_vendor vbmeta_vendor.img

25) Hit restart via Lineage Recovery....and back to fastboot :/

26) Used Lineage Recovery: format data/factory reset

27) Used Lineage Recovery format cache

28) Reboot from lineage recovery....back to fastboot.

29) Tried lineage Recovery format system - says no available "failed to bind"

30) Looks like SPFlash for me...

31) Downloaded official Unihertz firmware -- https://drive.google.com/drive/u/0/folders/0By1nhWOmuw2KdDhTUlFOZHpXQjg?sort=13&direction=a

32) Downloading TWRP installer from XDA posted a week ago (thanks!)

33) Use sideloading on LineageOS to successfully load TWRP

34) TWRP loads with power + up and seems to work perfectly well.

35) Power on without up button goes to dark screen with text "fastboot mode"

So, still fighting with SP flashtool drivers on a Win8 machine just upgraded to Win10, which is its own stupid mess.

I've had similar slogs through the jungle with at least five sony and samsung, but this one's especially frustrating as I just messed up the instructions. FWIW I don;t know if rebooting after step 13 before Magisk would have also kicked it into fastboot mode.

I'll post any successes and of course any ideas much appreciated.

Next step I'll try sideloading the vbmeta files across in TWRP and hope to fix it?

(update - can't seem to get adb to recognise the device in TWRP sideload mode.)

Again, many thanks to all who have put effort into building these tools - hopefully the details above are of some help.