How to SPLIT BOOT.IMG file into kernel and ramdisk.gz (Android)
This article shows how to split a boot.img file into kernel and ramdisk parts.
In Android systems kernel and initial ramdisk filesystem are usually joined into an only file, named boot.img, and flashed into the device.
Recover image files have same structure too.
mkbootimg is the tool which builds a boot.img file from its kernel and ramdisk parts.
Boot.img file could also contain a second filesystem within it.
Split boot.img file using a python script
Copy split_boot_img.py code at the end of this article in a file named split_boot_img.py
Then execute (you need to already have a boot.img file):
$ python split_boot_img.py -i boot.img -o parts # This splits boot.img, create parts directory and stores there zImage (kernel) and ramdisk.gz.