diff --git a/CMakeLists.txt b/CMakeLists.txt
index a56daef..f79ae2e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,13 +1,13 @@
 cmake_minimum_required(VERSION 3.5.1)
 
+project(n-adb)
+
 if ((CMAKE_HOST_SYSTEM_NAME MATCHES "Linux") AND (NOT (${CMAKE_SYSTEM_PROCESSOR} MATCHES "aarch64")))
 set(CMAKE_C_COMPILER /usr/bin/clang)
 set(CMAKE_CXX_COMPILER /usr/bin/clang++)
 set(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} -stdlib=libc++")
 endif()
 
-project(n-adb)
-
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 add_compile_options(-g)
 
diff --git a/README.md b/README.md
index 4599df4..7ee9eda 100644
--- a/README.md
+++ b/README.md
@@ -46,7 +46,7 @@ $ make CFLAGS=-fPIC CC=aarch64-linux-gnu-gcc DEB_HOST_ARCH=arm64 -f debian/libcr
 $ make CXXFLAGS=-fPIC CXX=aarch64-linux-gnu-g++ DEB_HOST_ARCH=arm64 -f debian/libssl.mk
 ```
 
-### build adb for linxu x86-64
+### build adb for linux x86-64
 
 **build on command line**
 
@@ -60,13 +60,23 @@ $ make -j8
 
 you need an remote linux pc, then config clion/vscode with it's remote development feature, it is so easy!
 
-## build adb target for linux aarch64
+### build adb target for linux aarch64
+
+**first, install toolchain**
 
 ```bash
-$ mkdir build && cd build
-$ cmake -DCMAKE_TOOLCHAIN_FILE=../aarch64_linux_toolchain.cmake ../
-$ make -j8
+$ wget 'https://developer.arm.com/-/media/Files/downloads/gnu-a/9.2-2019.12/binrel/gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz\?revision\=61c3be5d-5175-4db6-9030-b565aae9f766\&la\=en\&hash\=0A37024B42028A9616F56A51C2D20755C5EBBCD7' -O gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz
+$ tar xvf gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz --strip-components=1
+```
+
+**build with cmake**
+
 ```
+$ CC=clang CXX=clang++ cmake . -Bbuild-arm64 -DCMAKE_TOOLCHAIN_FILE=cmake/linux/toolchain-aarch64.cmake
+$ cmake --build build-arm64 --config Release
+```
+
+NOTE: please install a cmake with the newest version!
 
 ## build adb target for windows(only 32-bit supported!)
 
diff --git a/aarch64_linux_toolchain.cmake b/aarch64_linux_toolchain.cmake
deleted file mode 100644
index a750a60..0000000
--- a/aarch64_linux_toolchain.cmake
+++ /dev/null
@@ -1,13 +0,0 @@
-# ref: https://cmake.org/cmake/help/v3.9/manual/cmake-toolchains.7.html#cross-compiling-for-linux
-
-set(CMAKE_SYSTEM_NAME Linux)
-set(CMAKE_SYSTEM_PROCESSOR aarch64)
-
-set(CMAKE_C_COMPILER aarch64-linux-gnu-gcc)
-set(CMAKE_CXX_COMPILER arch64-linux-gnu-g++)
-
-set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
-set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
-set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
-set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
-
diff --git a/cmake/linux/toolchain-aarch64.cmake b/cmake/linux/toolchain-aarch64.cmake
new file mode 100644
index 0000000..b3a0c78
--- /dev/null
+++ b/cmake/linux/toolchain-aarch64.cmake
@@ -0,0 +1,25 @@
+set (CMAKE_SYSTEM_NAME "Linux")
+set (CMAKE_SYSTEM_PROCESSOR "aarch64")
+set (CMAKE_C_COMPILER_TARGET "aarch64-linux-gnu")
+set (CMAKE_CXX_COMPILER_TARGET "aarch64-linux-gnu")
+set (CMAKE_ASM_COMPILER_TARGET "aarch64-linux-gnu")
+set (CMAKE_SYSROOT "${CMAKE_CURRENT_LIST_DIR}/../toolchain/linux-aarch64/aarch64-none-linux-gnu/libc")
+
+# We don't use compiler from toolchain because it's gcc-8, and we provide support only for gcc-9.
+set (CMAKE_AR "${CMAKE_CURRENT_LIST_DIR}/../toolchain/linux-aarch64/bin/aarch64-none-linux-gnu-ar" CACHE FILEPATH "" FORCE)
+set (CMAKE_RANLIB "${CMAKE_CURRENT_LIST_DIR}/../toolchain/linux-aarch64/bin/aarch64-none-linux-gnu-ranlib" CACHE FILEPATH "" FORCE)
+
+set (CMAKE_C_FLAGS_INIT "${CMAKE_C_FLAGS} --gcc-toolchain=${CMAKE_CURRENT_LIST_DIR}/../toolchain/linux-aarch64")
+set (CMAKE_CXX_FLAGS_INIT "${CMAKE_CXX_FLAGS} --gcc-toolchain=${CMAKE_CURRENT_LIST_DIR}/../toolchain/linux-aarch64")
+set (CMAKE_ASM_FLAGS_INIT "${CMAKE_ASM_FLAGS} --gcc-toolchain=${CMAKE_CURRENT_LIST_DIR}/../toolchain/linux-aarch64")
+
+#set (LINKER_NAME "lld" CACHE STRING "" FORCE)
+#
+#set (CMAKE_EXE_LINKER_FLAGS_INIT "-fuse-ld=lld")
+#set (CMAKE_SHARED_LINKER_FLAGS_INIT "-fuse-ld=lld")
+#
+#set (HAS_PRE_1970_EXITCODE "0" CACHE STRING "Result from TRY_RUN" FORCE)
+#set (HAS_PRE_1970_EXITCODE__TRYRUN_OUTPUT "" CACHE STRING "Output from TRY_RUN" FORCE)
+#
+#set (HAS_POST_2038_EXITCODE "0" CACHE STRING "Result from TRY_RUN" FORCE)
+#set (HAS_POST_2038_EXITCODE__TRYRUN_OUTPUT "" CACHE STRING "Output from TRY_RUN" FORCE)
diff --git a/cmake/toolchain/linux-aarch64/README.txt b/cmake/toolchain/linux-aarch64/README.txt
new file mode 100644
index 0000000..11141ac
--- /dev/null
+++ b/cmake/toolchain/linux-aarch64/README.txt
@@ -0,0 +1,2 @@
+wget 'https://developer.arm.com/-/media/Files/downloads/gnu-a/9.2-2019.12/binrel/gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz\?revision\=61c3be5d-5175-4db6-9030-b565aae9f766\&la\=en\&hash\=0A37024B42028A9616F56A51C2D20755C5EBBCD7' -O gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz
+tar xvf gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz --strip-components=1