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LZ4 image extraction on Android Oreo 8.0

By August 12, 2018August 11th, 2020How to

Samsung Oreo firmwares use a new compression algorithm for their ext4 firmware files. It’s called a LZ4 format. You can’t open it with a DiskInternals Linux Reader on Windows. You need a tool for LZ4 image. I’m going to show how to use precompiled binary for file extraction. Github developer named Cyan4973 has released utility which allows to extract.

Manual way:

Follow these easy steps:

  • Download file from below.
  • Put in lz4 folder system.img.ext4.lz4 (which you extracted from the .tar.md5 file)
  • Open CMD line for the lz4 folder
  • Type lz4.exe -d system.img.lz4 system.img.ext4 (NOTE: LZ4 file must match the one you extracted from the tar file.)
  • Wait for the utility to finish, it will say something like that: ,,system.img.lz4 : decoded 2408398332 bytes”
  • Proceed to extract the newly created ext4 image


Brief example how to open Command Prompt and use cd command to the directory where you extracted these files.

In order to get “Open Powershell window” you must use SHIFT + RIGHT MOUSECLICK combination.

In next tutorial I will teach how to use ASSAYYED’s KITCHEN and proceed with complete extraction and deodexing the ROM.

Folder you are targeting
Click here to open Powershell
Type command and wait for it to finish
Here’s your newly created EXT4 image

Easiest way:

This is a most complete method. Without typing any lines of code. Saving You guys from making hands dirty. I’ve made a shell script for that. It requires that you have LZ4 v1.9.2 extracted already. Just extract this make.bat into a lz4_v1_9_2_win64 folder. When extracted into a root directory just double-click on it. Shell will prompt to overwrite if a previous lz4 image(s) exists.

NOTE: Files must be named in order to decode: system.img.lz4, boot.img.lz4, recovery.img.lz4, cache.img.lz4, hidden.img.lz4


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