How to Unpack system.new.dat.br file which I found in Android 8.1 rom(aosp Based)
I recently downloaded a aosp based rom from xda for my Xiaomi redmi note 3 pro(kenzo) device. It’s name is «Pixel experience android 8.1». when extract the rom zip file, there is a file name «system.new.dat.br» , I want to extract it or unpack. but i can’t do it. please can any one help me about this how to unpack the new type system.
5 Answers 5
On Linux this can be decompressed with brotli like this (Ubuntu):
$ sudo apt install brotli $ brotli --decompress system.new.dat.br -o system.new.dat system.new.dat.br is system.new.dat compressed into a .br (brotli) file.
On Windows, you can use Eric Lawrence’s Brotli.exe to decompress the .br file to system.new.dat which you can extract as before.
Put system.new.dat.br and Brotli.exe in a folder, open a command line in the folder and «brotli —decompress —in system.new.dat.br —out system.new.dat»
if you want to extract it to modify the contents (i.e. edit files and folders), then after extracting it with the brotli tool ( as mentioned in the other comments) you have to decompress/extract the sparse android data (.dat) to an ext2/3/4 raw image. For that you would need the sdat2img tool.
sdat2img system.transfer.list system.new.dat system.img after which you would be able to mount system.img to a folder and then be able to access the contents/modify it.
After that, if you want to flash it to device, you may have to convert it to sparse image for android. For that you would need the img2simg tool.
following the previous example above,
img2simg system.img sparse_image.img [blocksize can be skipped] Extracting proprietary blobs from LineageOS zip files
Proprietary blobs can be extracted either from a device already running LineageOS or from a LineageOS installable zip. In this guide we will describe the steps required to extract proprietary files from installable zips.
Before beginning, it is required to know the difference between the types of OTAs:
- Block-based OTA: the content of the system partition is stored inside of an .dat / .dat.br file as binary data.
- File-based OTA: the content of the system partition is available inside a folder of the zip named system .
- Payload-based OTA: the content of the system partition is stored as an .img file inside of payload.bin .
If your zip has no system folder or it is nearly empty and a file named system.transfer.list exists at the root level, then what you have is a block-based OTA. Jump to Extracting proprietary blobs from block-based OTAs in this case.
If you have the entire content of the system partition inside the system folder and no system.transfer.list , then what you have is a file-based OTA. See Extracting proprietary blobs from file-based OTAs.
You may also have a payload-based OTA, which is what your device will use if it uses the A/B partitioning system. If that is what you have, jump to Extracting proprietary blobs from payload-based OTAs.
Extracting proprietary blobs from block-based OTAs
Some block-based OTAs are split into multiple files, each for separate partitions like system, vendor, product, oem, odm and others. You can verify if yours is split by looking for the corresponding *.transfer.list files for each in the root of the installable LineageOS zip.
If you have a split block-based OTA file then you will need to extract, decompress and convert each one in a similar manner to system and vendor as outlined below.
If you do not have a split OTA file, you may skip any step that references vendor.transfer.list and vendor.new.dat.br or vendor.new.dat
Create a temporary directory and move there:
mkdir ~/android/system_dump/ cd ~/android/system_dump/ Extract system.transfer.list and system.new.dat.br or system.new.dat from the installable LineageOS zip:
unzip path/to/lineage-*.zip system.transfer.list system.new.dat* where path/to/ is the path to the installable zip.
If your OTA includes vendor.transfer.list and vendor.new.dat.br or vendor.new.dat (or others), extract them from the installable LineageOS zip as well:
unzip path/to/lineage-*.zip vendor.transfer.list vendor.new.dat* where path/to/ is the path to the installable zip.
In the case of system.new.dat.br / vendor.new.dat.br / super.new.dat.br /etc. (a brotli archive) exists, you will first need to decompress them using the brotli utility:
sudo apt-get install brotli brotli --decompress --output=system.new.dat system.new.dat.br And if you have a vendor.dat.new.br (or others) file:
brotli --decompress --output=vendor.new.dat vendor.new.dat.br You now need to get a copy of sdat2img . This script can convert the content of block-based OTAs into dumps that can be mounted. sdat2img is available at the following git repository that you can clone with:
git clone https://github.com/xpirt/sdat2img Once you have obtained sdat2img , use it to extract the system image:
python sdat2img/sdat2img.py system.transfer.list system.new.dat system.img You should now have a file named system.img that you can mount as follows:
mkdir system/ sudo mount system.img system/ And if you have a vendor.dat.new (or others) file:
python sdat2img/sdat2img.py vendor.transfer.list vendor.new.dat vendor.img If you have a file named vendor.img , or similar, you can mount them as follows:
sudo rm system/vendor sudo mkdir system/vendor sudo mount vendor.img system/vendor/ Unlike the above, if you have a super.dat.new file:
python sdat2img/sdat2img.py super.transfer.list super.new.dat super.img You will now have a file named super.img , You need to get a copy of lpunpack to extract images from it. This script can extract the content of the Super partition into it’s respective component partitions that can be mounted. Luckily, lpunpack is easily buildable, executing the following from a LineageOS 17.1 or greater tree:
source build/envsetup.sh breakfast your_device_codename m lpunpack Once you have built lpunpack , use it to extract the super image:
lpunpack super.img /output/dir You must also now mount any other image files that you have in their respective directories as shown above with vendor.img .
After you have mounted the image(s), move to the root directory of the sources of your device and run extract-files.sh as follows:
./extract-files.sh ~/android/system_dump/ This will tell extract-files.sh to get the files from the mounted system dump rather than from a connected device.
Once you’ve extracted all the proprietary files, unmount the vendor dump if you mounted it earlier:
sudo umount ~/android/system_dump/system/vendor Then unmount the system dump:
sudo umount ~/android/system_dump/system Finally, unmount any other images before deleting the no longer needed files:
Extracting proprietary blobs from file-based OTAs
Create a temporary directory to extract the content of the zip and move there:
mkdir ~/android/system_dump/ cd ~/android/system_dump/ Extract the system folder from the zip:
unzip path/to/lineage-*.zip system/* where path/to/ is the path to the installable zip.
After you have extracted the system folder, move to the root directory of the sources of your device and run extract-files.sh as follows:
./extract-files.sh ~/android/system_dump/ This will tell extract-files.sh to get the files from the extracted system dump rather than from a connected device.
Once you’ve extracted all the proprietary files, you can delete the files that were extracted from the zip:
Extracting proprietary blobs from payload-based OTAs
Create a temporary directory to extract the content of the zip and move there:
mkdir ~/android/system_dump/ cd ~/android/system_dump/ Extract the payload.bin file from the LineageOS installation zip file:
unzip /path/to/lineage-*.zip payload.bin where /path/to/ is the path to the installable zip.
You will now need to use a tool called update-payload-extractor .
To use the tool, you will need python-protobuf, if you do not already have it:
sudo apt-get install python-protobuf You can now extract the .img files from the payload:
- If you have a LineageOS build tree checked out already, you can just run the script to extract the payload:
python /path/to/lineage-tree/lineage/scripts/update-payload-extractor/extract.py payload.bin --output_dir ./ git clone https://github.com/LineageOS/scripts python /path/to/scripts/update-payload-extractor/extract.py payload.bin --output_dir ./ It will take a few moments. Once it’s done, we will need to mount the system.img file, and the vendor.img , odm.img , product.img , and system_ext.img files if they exist, to obtain the complete set of proprietary blobs:
mkdir system/ sudo mount -o ro system.img system/ sudo mount -o ro vendor.img system/vendor/ sudo mount -o ro odm.img system/odm/ sudo mount -o ro product.img system/product/ sudo mount -o ro system_ext.img system/system_ext/ Move to the root directory of the sources of your device and run extract-files.sh as follows:
./extract-files.sh ~/android/system_dump/ This will tell extract-files.sh to extract the proprietary blobs from the mounted system dump rather than a connected device.
Once it is done, unmount the system dump and remove the now unnecessary files:
sudo umount -R ~/android/system_dump/system/ rm -rf ~/android/system_dump/ © 2016 — 2023 The LineageOS Project
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