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I've soft-bricked my Samsung Galaxy A40FN running Android 9.0 Pie while attempting to disable bloatware via ADB and I'm currently searching for a solution to recover my data and get the system back running. The phone is stuck in a boot loop, but I can get into recovery mode and download mode.

FRP lock is off (no Google account registered on this device) and I didn't activate any encryption on my part.

I didn't try wiping/factory-resetting yet as I need to rescue my data first. One possible solution for this could be to flash the original firmware using Odin while leaving the /data folder untouched:

Source: https://forum.xda-developers.com/t/help-how-to-flash-without-losing-data.3704358/

https://forum.xda-developers.com/t/help-how-to-flash-without-losing-data.3704358/

Question: Does anyone have experience with retaining personal data during a firmware flash and know how to verify the authenticity of the files downloaded from unofficial sources such as SamFW?

I.e. does Samsung publish MD5 hashes of official firmware updates and would comparing these hashes/checksums be a reliable method to verify that the files have not been tampered with, considering that firmware files are typically 4-5 GB large?

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    Flashing the system image will not help you because you have not uninstalled the apps but only disabled them. Modifications to the system partitions is not possible unless the device is rooted (but if I remember correctly your device is not rooted). So all apps are still present but the config files from the user data partition tells Android they are disabled which causes your device to not boot.
    – Robert
    Jun 18 at 18:25
  • @Robert So doing pm uninstall only removes the apps from the "standard (non-root) user", but they're physically still on the device (I watched the apps disappearing one after the other from the apps list)? Are you suggesting that I need to root the device first in order to get access to the data folder? If yes, is this possible without accidentally wiping everything?
    – kerstin92
    Jun 18 at 20:59
  • Rooting does not accidentally wipe the device, it does so by definition. When you unlock the bootloader everything is wiped as this opens a big back door on the encrypted user data.
    – Robert
    Jun 18 at 23:03
  • @Robert ...and I guess this behavior is hardcoded in some chip and cannot be modified on software level? Or is it?
    – kerstin92
    Jun 18 at 23:05
  • Of course not, this would be a disastrous security vulnerability for the Android ecosystem. In the early days of Android 4 there were a few devices which had implemented bootloader unlock factory reset in a defect way, but since that time it is known as a crucial point and thus the manufacturer have this functionality on their checklist.
    – Robert
    Jun 19 at 10:32

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Okay, I can answer my own question: You can download firmware files directly from Samsung using open-source tools such as SamLoader.

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