How to build alone

setup environment

source environment-setup    //<ANDROID_SOURCE> directory

you also can setup manually:

cd <ANDROID_SOURCE>
export PATH=$PATH:`pwd`/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin:`pwd`/bootable/bootloader/uboot-imx/tools
export ARCH=arm
export CROSS_COMPILE=arm-eabi-

build kernel default case

cp arch/arm/configs/imx_v7_android_no_logo_defconfig arch/arm/configs/imx_v7_android_defconfig
make imx_v7_android_defconfig

build kernel with keep uboot logo feature

cp arch/arm/configs/imx_v7_android_logo_defconfig arch/arm/configs/imx_v7_android_defconfig
make imx_v7_android_defconfig

build

make uImage LOADADDR=0x10008000