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 -j12 --no-tags
    $repo start android-11.0.0_r35 --all
  )
	   
  - Then, 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_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
  
  a) cd android 
  b) make -C kernel-4.19 O=../out ARCH=arm64 CC=../prebuilts/clang/host/linux-x86/clang-r383902/bin/clang CLANG_TRIPLE=aarch64-linux-gnu- CROSS_COMPILE=../prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin/aarch64-linux-android- LGE_TARGET_PLATFORM=mt6765 LGE_TARGET_DEVICE=mdh50lm LGE_LAMP_DEVICE=yes MTK_DTBO_FEATURE=yes PLATFORM_DTB_NAME=mt6765 PROJECT_DTB_NAMES=muse6765_64_dh50_r muse6765_64_dh50_r_debug_defconfig 
  c) make -C kernel-4.19 O=../out ARCH=arm64 CC=../prebuilts/clang/host/linux-x86/clang-r383902/bin/clang CLANG_TRIPLE=aarch64-linux-gnu- CROSS_COMPILE=../prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin/aarch64-linux-android- LGE_TARGET_PLATFORM=mt6765 LGE_TARGET_DEVICE=mdh50lm LGE_LAMP_DEVICE=yes MTK_DTBO_FEATURE=yes PLATFORM_DTB_NAME=mt6765 PROJECT_DTB_NAMES=muse6765_64_dh50_r headers_install 
  d) make -j8 -C kernel-4.19 O=../out ARCH=arm64 CC=../prebuilts/clang/host/linux-x86/clang-r383902/bin/clang CLANG_TRIPLE=aarch64-linux-gnu- CROSS_COMPILE=../prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin/aarch64-linux-android- LGE_TARGET_PLATFORM=mt6765 LGE_TARGET_DEVICE=mdh50lm LGE_LAMP_DEVICE=yes MTK_DTBO_FEATURE=yes PLATFORM_DTB_NAME=mt6765 PROJECT_DTB_NAMES=muse6765_64_dh50_r

	* "-j8" : The number, 8, is the number of multiple jobs to be invoked simultaneously. 
  - After build, you can find the build image(zImage) at out/arch/arm64/boot

