How to build zenfone kernel

#1 download aosp source code
	cd [working dir]
	repo init -u https://android.googlesource.com/platform/manifest -b android-5.0.0_r7
	repo sync

#2 extract kernel source code to working dir
	tar -zxvf [kernel-source].tar.gz

#3 build 'minigzip' and 'openssl' modules
	source build/envsetup.sh
	lunch aosp_x86-eng
	make minigzip openssl

#4 build kernel image and modules
## define TARGET_DEVICE to overwrite
## available options : 
## 	TARGET_DEVICE=hd  (ZE550ML)
##	TARGET_DEVICE=fhd (ZE551ML - default)

	make -f KernelMakefile TARGET_DEVICE=hd build_kernel
  	or
	make -f KernelMakefile TARGET_DEVICE=hd modules_install