klozz/android-blob-utility

Blob tracer for AOSP-based ROMs

Android Blob Utility

by JackpotClavin

The Android Blob Utility is a program designed to make developing AOSP-based ROMs easier for developers. What is does is it allows the developer to pick proprietary file, type the file's absolute path, and this program will spit back every library that should be needed in order to get that library or daemon to run on an AOSP ROM.

How does it work? First the developer must dump their entire stock ROM's software to their computer, so that typing the command: $ ls /home/android/dump/build.prop will yield their device's build.prop. This is just meant to ensure that you have the correct path it is valid. Next, you are to compile this program with the make command. Once you run it, the program will prompt you to enter whatever the SDK version of you /system dump happens to be (check your /system/build.prop), for instance if your /system dump is Android 4.3, type in 18 (use the following site for guidelines). Secondly, the program will ask you for the location of your /system dump; so if the build.prop file is under /home/android/dump/build.prop, you can just type: /home/android/dump and press enter. Then the program will prompt you for the manufacturer name and device name. In the case of my Verizon LG G2, when prompted for the manufacturer(vendor) and device name, I inputted lge, and vs980, respectively. For the third step of getting the necessary blobs, this program will prompt you to enter however many blobs files you want this program to process. If you want to only process one blob, type 1 and hit enter. After you enter the amount of blobs you want this program to process, you will type the absolute path to the actual blob (see the [example program usage] (https://github.com/JackpotClavin/Android-Blob-Utility/blob/master/Example_Usage.txt)), and this program will print out all of the proprietary blobs that are mentioned in that particular blob that you entered, that aren't in the emulator's /system dump. That means that those files are either have to be built from source, or are proprietary and must be copied into the ROM's build. This program will also format the blobs such that it is ready to be placed into a vendor-blobs.mk file in your vendor folder of the ROM's source tree root.

What makes this program great is that it doesn't just get the shared libraries necessary to appease the linker, but it takes another step; it also catches the blobs that may slip past the linker because they are called in the actual code of the blob. Simply copying the shared libraries just appeases the linker, but the blob still not run properly as the blob may want additional libraries.

This program also searches recursively, so each and every blob that is found is also processed through the searching algorithm, to see which blobs that library also needs to run, so we cover all of the bases in order to get a proprietary library or daemon to run.

The following example was used on my LG G2. Running this program with the two main proprietary files related to the camera /system/bin/mm-qcamera-daemon and /system/lib/hw/camera.msm8974.so, this program nicely printed out every proprietary file needed to get the camera working, and formatted it so that one can easily copy the program's output to a vendor-blobs.mk file, instead of having to keep pushing files until the linker is satisfied, or having to find libraries that aren't shared libraries, but are called in the actual code of the proprietary file.

Example program usage can be found in the Example_Usage.txt in this folder.