1. Android build
  - Download original android source code ( android-11.0.0_r35) from http://source.android.com   
  ( $repo init -u https://android.googlesource.com/platform/manifest -b android-11.0.0_r35
    $repo sync -cdq -j11 --no-tags
    $repo start android-11.0.0_r35
  )
  - And, merge the source into the android source code
  
  - 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_S.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-4.14 
    2. mkdir -p out 
    3. export PATH=`pwd`/../../prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin:$PATH 
    4. export CROSS_COMPILE=`pwd`/../../prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin/aarch64-linux-android- 
    5. make O=./out ARCH=arm64 vendor/alphalm_lao_com_defconfig 
    6. make O=./out ARCH=arm64 REAL_CC=`pwd`/../../prebuilts/clang/host/linux-x86/clang-r353983c/bin/clang CLANG_TRIPLE=aarch64-linux-gnu- -j4

     * "-j4" : The number, 4, is the number of multiple jobs to be invoked simultaneously. 
        - After build, you can find the build image(Image.gz) at out/arch/arm64/boot.




