I'm facing an issue that makes my device unusable and unflashable. It is corrupted so I can't access the system. OTA sideloading fails. Factory reset fails. Flashing doesn't work because the bootloader is locked. I can't unlock it because I can't access the system.
Three days ago the system auto downloaded an update as usual and I restarted it to install the update, as usual. The installation process failed, and since then each time I turn the device on, the startup screen displays the red warning "Your device is corrupt". GrapheneOS is launched for a few seconds before restarting.
I tried to sideload the latest OTA update with ADB, using several different USB-C to USB-A and USB-C to USB-C cables (including the original one shipped with the phone) on 2.0 and 3.0 USB ports on three different computers running various operating systems. It doesn't work.
Either the process hangs forever at 0% or 1%, or the signature verification stops below 50% completion.
adb: failed to read command: Success
and the device immediately restarts.
I then tried to perform a factory reset from the recovery menu. The process logs an error and that data wipe is complete:
ERROR: recovery: [libfs_mgr]Unable to enable ext4 verity o
n /dev/block/platform/14700000.ufs/by-name/metadata because
/system/bin/tune2fs is missing
Wiping Titan M...
Data wipe complete.
Now, each time I try to access the system, it shows the initial setup wizard, then keeps restarting within a few seconds.
My last resort was to try to flash the device with the factory image using fastboot, in order to install GrapheneOS once the device is properly reset. It doesn't work, because the bootloader is locked.
I also tried to do it using the Android Flash Tool, which can't work either, for the very same reason.
@abrasamji suggested on the #grapheneos:grapheneos.org chat room:
You will want to continue debugging the OTA sideload. Make sure to use the full size OTA as others said. Do describe what exactly doesn't work. There is also a chance of hardware failure with some bad timing.
and @Bruno suggested:
If you have any(?) of the Snapdragon powered Pixels you could search about how to rescue it with EDL mode ig? I don't know if that's still a thing and if it is, how feasible it is, or if Tensor powered Pixels even have something like EDL mode at all
I don't know how to debug the OTA sideload nor what EDL mode is.
Is there a way to flash the device without unlocking the bootloader, or to unlock the bootloader without accessing the system? Or is my phone definitely unusable?
I couldn't find any relevant information about this kind of issue on the web.
Any help, advice or suggestion would be greatly appeciated, thanks a lot.