1. Android build
  - Download original android source code ( android-11.0.0_r17 ) from http://source.android.com
  ( $repo init -u https://android.googlesource.com/platform/manifest -b android-11.0.0_r17
    $repo sync -cdq -j12 --no-tags
    $repo start  android-11.0.0_r17 --all
  )
  
  - Then, merge the source into the android source code
  
    Before giving the android build, merge the kernel source code 
    to merge the kernel source code, Uncompress using following command at the android directory
    a) tar -xvzf *_Kernel_R.tar.gz
	
  - Run following scripts to build android
    a) source build/envsetup.sh
    b) lunch 1
    c) make -j4
  - When you compile the android source code, you have to add google original prebuilt source(toolchain) into the android directory.
  - After build, you can find output at out/target/product/generic

2. Kernel Build  
  - Uncompress using following command at the android directory

    a) tar -xvzf *_Kernel_R.tar.gz

  - When you compile the kernel source code, you have to add google original "prebuilt" source(toolchain) into the android directory.
  - Run following scripts to build kernel
  
      1) cd kernel/msm-4.4
      2) mkdir -p out
      3) make ARCH=arm64 O=./out REAL_CC=../../../prebuilts/clang/host/linux-x86/clang-r353983c/bin/clang CLANG_TRIPLE=aarch64-linux-gnu- CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin/aarch64-linux-android- DTC_EXT=../../../prebuilts/misc/linux-x86/dtc/dtc phoenix_lgu_kr-perf_defconfig
      4) make ARCH=arm64 O=./out REAL_CC=../../../prebuilts/clang/host/linux-x86/clang-r353983c/bin/clang CLANG_TRIPLE=aarch64-linux-gnu- CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin/aarch64-linux-android- DTC_EXT=../../../prebuilts/misc/linux-x86/dtc/dtc -j4
     
	 * "-j4" : The number, 4, is the number of multiple jobs to be invoked simultaneously.
	 
	 - After build, you can find the build image(zImage) at kernel/msm-4.4/out/arch/arm64/boot