My Tecno Spark 10 Pro (MediaTek Helio G88, Android 12) bootlooped after a banking app froze. Now it boots straight into stock recovery with the message that Android cannot be loaded and data may be corrupt. The bootloader is unlocked. I hooked it up to an Android tablet via OTG with Bugjaeger. The device uses A/B partitioning and was running on slot b. I switched it to slot a via fastboot, but slot a gives the exact same recovery loop, so the issue is clearly a corrupted userdata partition failing to mount during early init. All I need is my local KeePass database file from internal storage. I know modern Android uses File-Based Encryption with keys sealed in the TEE, but since my bootloader is unlocked, is there any known way via fastboot, MTK tools, or custom boot images to extract or decrypt that single file before I wipe the device? Or is it completely unrecoverable once the filesystem fails to mount?

My Tecno Spark 10 Pro (MediaTek Helio G88, Android 12) bootlooped after a banking app froze. Now it boots straight into stock recovery with the message that Android cannot be loaded and data may be corrupt. The bootloader is unlocked. I hooked it up to an Android tablet via OTG with Bugjaeger. The device uses A/B partitioning and was running on slot b. I switched it to slot a via fastboot, but slot a gives the exact same recovery loop, so the issue is clearly a corrupted userdata partition failing to mount during early init. All I need is my local KeePass database file from internal storage. I know modern Android uses File-Based Encryption with keys sealed in the TEE, but since my bootloader is unlocked, is there any known way via fastboot, MTK tools, or custom boot images to extract or decrypt that single file before I wipe the device? Or is it completely unrecoverable once the filesystem fails to mount?

  • hexagonwin@lemmy.todayEnglish
    1·
    3 days ago

    in some cases i’ve seen fastboot command return error on console but actually succeed in executing the wanted behavior, so it might be the case here that our boot.img did successfully boot.

    by ‘device reboots and trying to start android’, do you mean the device actually rebooted again to bootloader stage (e.g. vibrate and show manufacturer logo), or just boot android without that step? an easy way to confirm this is by holding fastboot or recovery hotkey right after fastboot command. if it did reboot and start again from bootloader it will enter fastboot/recovery, but if it didn’t and actually booted our new boot.img it would just boot android

    • lipen@reddthat.comOPEnglish
      1·
      3 days ago

      after fastboot boot error I immediately held volume up and the phone showed TECNO logo and then went to “No command” screen.

      • hexagonwin@lemmy.todayEnglish
        1·
        1 day ago

        hey can you confirm that the original unmodified boot.img doesn’t return failed while the new one does?

      • hexagonwin@lemmy.todayEnglish
        2·
        3 days ago

        ah, damn. it seems like it completely failed to boot…

        i’ll try another go at making a new boot.img and let you know soon. kinda out of ideas at this point tbh.