Every Android kernel is made of few parts, which (depending on the OEM) contains a zImage created during kernel compilation and a ramdisk where some device-specific settings are stored. Sometimes, the ramdisk contains a recovery, logo, and so on.
If you’ve ever tried to work on a precompiled kernel, you’ve noticed that it can’t be extracted with a simple archive manager. Rather, you need some tools capable of unpacking and repacking the kernel as an IMG file. These tools can be easily built on Linux. And thanks to XDA Senior Member A.S._id, you can download them easily and compile your 0wn.
The current set of tools includes such binaries as: mkbootfs, simg2simg, make_ext4fs, mkbootimg, ext2simg, img2simg, simg2img, sgs4ext4fs, and unpackbootimg. Some of them were created by XDA Senior Recognized Developer Chainfire and the CyanogenMod team.
The compilation process is presented in the thread. It’s really simple, and needs just two commands. If you have problems executing them, don’t forget to set the correct permissions by setting the files as executable. After compilation, you end up with binaries that can be used in the kernel modification process.
Naturally, this tool works only on Linux machines. Having configured Github account is also recommended. You can learn more about those binaries by visiting the original thread._________