diff --git a/01_build_src.sh b/01_build_src.sh
index 8172079..66f4d6c 100755
--- a/01_build_src.sh
+++ b/01_build_src.sh
@@ -1,14 +1,96 @@
 #!/bin/sh
 
-core_num=`nproc`
-kernel_install=`pwd`"/work/kernel_install"
-glibc_install=`pwd`"/work/glibc_install"
-busybox_install=`pwd`"/work/busybox_install"
-libgcc_install=`pwd`"/work/libgcc_install"
-binutils_install=`pwd`"/work/binutils_install"
+#-----------------------------------------------
+#
+# 导入公共变量
+#
+#-----------------------------------------------
+. ./common.sh
+
+#LINUX_SRC_URL=https://kernel.org/pub/linux/kernel/v4.x/linux-4.14.9.tar.xz
+LINUX_SRC_URL=https://mirror.bjtu.edu.cn/kernel/linux/kernel/v4.x/linux-4.14.9.tar.xz
+#GLIBC_SRC_URL=https://ftp.gnu.org/gnu/glibc/glibc-2.32.tar.bz2
+GLIBC_SRC_URL=https://mirrors.ustc.edu.cn/gnu/glibc/glibc-2.32.tar.bz2
+BUSYBOX_SRC_URL=https://busybox.net/downloads/busybox-1.34.1.tar.bz2
+#GCC_SRC_URL=https://ftpmirror.gnu.org/gcc/gcc-7.5.0/gcc-7.5.0.tar.xz
+GCC_SRC_URL=https://mirrors.ustc.edu.cn/gnu/gcc/gcc-7.5.0/gcc-7.5.0.tar.xz
+#BINUTILS_SRC_URL=https://ftp.gnu.org/gnu/binutils/binutils-2.36.tar.xz
+BINUTILS_SRC_URL=https://mirrors.ustc.edu.cn/gnu/binutils/binutils-2.36.tar.xz
 
 export CFLAGS="-Os -s -fno-stack-protector -fomit-frame-pointer -U_FORTIFY_SOURCE"
 
+#----------------------------------------------
+#
+# 下载源码
+#
+#----------------------------------------------
+mkdir -pv source
+cd source
+
+LINUX_SRC_NAME=$(file_name ${LINUX_SRC_URL})
+if [ ! -f ${LINUX_SRC_NAME} ]; then 
+  wget $LINUX_SRC_URL 
+fi
+
+GLIBC_SRC_NAME=$(file_name ${GLIBC_SRC_URL})
+if [ ! -f ${GLIBC_SRC_NAME} ]; then
+  wget $GLIBC_SRC_URL
+fi
+
+BUSYBOX_SRC_NAME=$(file_name ${BUSYBOX_SRC_URL})
+if [ ! -f ${BUSYBOX_SRC_NAME} ]; then 
+  wget $BUSYBOX_SRC_URL 
+fi
+
+GCC_SRC_NAME=$(file_name ${GCC_SRC_URL})
+if [ ! -f ${GCC_SRC_NAME} ]; then 
+  wget $GCC_SRC_URL 
+fi
+
+BINUTILS_SRC_NAME=$(file_name ${BINUTILS_SRC_URL})
+if [ ! -f ${BINUTILS_SRC_NAME} ]; then
+  wget $BINUTILS_SRC_URL
+fi
+
+cd ..
+
+#---------------------------------------------
+#
+# 解压源码 
+#
+#---------------------------------------------
+mkdir -pv ${build_dir} 
+
+LINUX_SRC_DIR=${build_dir}"/"$(file_dirname ${LINUX_SRC_NAME} .tar.xz)
+if [ ! -d ${LINUX_SRC_DIR} ]; then
+  echo "unzip ${LINUX_SRC_NAME} source code"
+  tar xf source/${LINUX_SRC_NAME} -C ${build_dir}
+fi
+
+GLIBC_SRC_DIR=${build_dir}"/"$(file_dirname ${GLIBC_SRC_NAME} .tar.bz2)
+if [ ! -d ${GLIBC_SRC_DIR} ]; then
+  echo "unzip ${GLIBC_SRC_NAME} source code"
+  tar xf source/${GLIBC_SRC_NAME} -C ${build_dir}
+fi
+
+BUSYBOX_SRC_DIR=${build_dir}"/"$(file_dirname ${BUSYBOX_SRC_NAME} .tar.bz2)
+if [ ! -d ${BUSYBOX_SRC_DIR} ]; then
+  echo "unzip ${BUSYBOX_SRC_NAME} source code"
+  tar xf source/${BUSYBOX_SRC_NAME} -C ${build_dir}
+fi
+
+GCC_SRC_DIR=${build_dir}"/"$(file_dirname ${GCC_SRC_NAME} .tar.xz)
+if [ ! -d ${GCC_SRC_DIR} ]; then
+  echo "unzip ${GCC_SRC_NAME} source code"
+  tar xf source/${GCC_SRC_NAME} -C ${build_dir}
+fi
+
+BINUTILS_SRC_DIR=${build_dir}"/"$(file_dirname ${BINUTILS_SRC_NAME} .tar.xz)
+if [ ! -d ${BINUTILS_SRC_DIR} ]; then
+  echo "unzip ${BINUTILS_SRC_NAME} source code"
+  tar xf source/${BINUTILS_SRC_NAME} -C ${build_dir}
+fi
+
 #-----------------------------------------------
 #
 # 重新生成目标文件
@@ -19,137 +101,67 @@ if [ "$1" != "" ]; then
     exit
   fi
   echo "rebuild"
-  cd work
-  rm -rf kernel_install glibc_install busybox_install libgcc_install binutils_install
+  cd ${build_dir} 
+  rm -rf linux_install glibc_install busybox_install gcc_install binutils_install
   # 编译内核, 最终所有模块都装到目录 /lib/modules/4.14.9
-  if [ ! -d "kernel_install" ]; then
-    mkdir -pv kernel_install && cd linux-4.14.9 
-    make INSTALL_HDR_PATH=${kernel_install} headers_install -j8 && cp arch/x86_64/boot/bzImage ${kernel_install} && cd ..
+  if [ ! -d "linux_install" ]; then
+    mkdir -pv linux_install && cd ${LINUX_SRC_DIR} 
+    make INSTALL_HDR_PATH=${linux_install} headers_install -j8 && cp arch/x86_64/boot/bzImage ${linux_install} && cd ..
   fi
 
   # 编译glibc
   if [ ! -d "glibc_install" ]; then
-    mkdir -pv glibc_install && cd glibc-2.32
+    mkdir -pv glibc_install && cd ${GLIBC_SRC_DIR} 
     mkdir -pv build && cd build
     make install -j8 DESTDIR=${glibc_install} && cd .. && cd ..
   fi
 
   # 编译 busybox 
   if [ ! -d "busybox_install" ]; then
-    mkdir -pv busybox_install && cd busybox-1.34.1
+    mkdir -pv busybox_install && cd ${BUSYBOX_SRC_DIR}
     make CONFIG_PREFIX=${busybox_install} install && cd ..
   fi
 
   # 编译 libgcc
-  if [ ! -d "libgcc_install" ]; then
-    mkdir -pv libgcc_install && cd gcc-7.5.0
-    make install -j8 DESTDIR=${libgcc_install} && cd ..
+  if [ ! -d "gcc_install" ]; then
+    mkdir -pv gcc_install && cd ${GCC_SRC_DIR}
+    make install -j8 DESTDIR=${gcc_install} && cd ..
   fi
 
   # 编译 binutils
   if [ ! -d "binutils_install" ]; then
-    mkdir -pv binutils_install && cd binutils-2.36
+    mkdir -pv binutils_install && cd ${BINUTILS_SRC_DIR}
     make install -j8 DESTDIR=${binutils_install} && cd ..
   fi  
   cd ..
   exit
 fi
 
-#----------------------------------------------
-#
-# 下载源码
-#
-#----------------------------------------------
-mkdir -pv source
-cd source
-
-#KERNEL_SOURCE_URL=https://kernel.org/pub/linux/kernel/v4.x/linux-4.14.9.tar.xz
-KERNEL_SOURCE_URL=https://mirror.bjtu.edu.cn/kernel/linux/kernel/v4.x/linux-4.14.9.tar.xz
-if [ ! -f "linux-4.14.9.tar.xz" ]; then 
-  wget $KERNEL_SOURCE_URL 
-fi
-
-#GLIBC_SOURCE_URL=https://ftp.gnu.org/gnu/glibc/glibc-2.32.tar.bz2
-GLIBC_SOURCE_URL=https://mirrors.ustc.edu.cn/gnu/glibc/glibc-2.32.tar.bz2
-if [ ! -f "glibc-2.32.tar.bz2" ]; then
-  wget $GLIBC_SOURCE_URL
-fi
-
-BUSYBOX_SOURCE_URL=https://busybox.net/downloads/busybox-1.34.1.tar.bz2
-if [ ! -f "busybox-1.34.1.tar.bz2" ]; then 
-  wget $BUSYBOX_SOURCE_URL 
-fi
-
-#GCC_SOURCE_URL=https://ftpmirror.gnu.org/gcc/gcc-7.5.0/gcc-7.5.0.tar.xz
-GCC_SOURCE_URL=https://mirrors.ustc.edu.cn/gnu/gcc/gcc-7.5.0/gcc-7.5.0.tar.xz
-if [ ! -f "gcc-7.5.0.tar.xz" ]; then 
-  wget $GCC_SOURCE_URL 
-fi
-
-#BINUTILS_SOURCE_URL=https://ftp.gnu.org/gnu/binutils/binutils-2.36.tar.xz
-BINUTILS_SOURCE_URL=https://mirrors.ustc.edu.cn/gnu/binutils/binutils-2.36.tar.xz
-if [ ! -f "binutils-2.36.tar.xz" ]; then
-  wget $BINUTILS_SOURCE_URL
-fi
-
-cd ..
-
-#---------------------------------------------
-#
-# 解压源码 
-#
-#---------------------------------------------
-mkdir -pv work
-
-if [ ! -d "./work/linux-4.14.9" ]; then
-  echo "unzip kernel source"
-  tar xf source/linux-4.14.9.tar.xz -C work/
-fi
-
-if [ ! -d "./work/glibc-2.32" ]; then
-  echo "unzip glibc source"
-  tar xf source/glibc-2.32.tar.bz2 -C work/
-fi
-
-if [ ! -d "./work/busybox-1.34.1" ]; then
-  echo "unzip busybox source"
-  tar xf source/busybox-1.34.1.tar.bz2 -C work/
-fi
-
-if [ ! -d "./work/gcc-7.5.0" ]; then
-  echo "unzip gcc source"
-  tar xf source/gcc-7.5.0.tar.xz -C work/
-fi
-
-if [ ! -d "./work/binutils-2.36" ]; then
-  echo "unzip binutils source"
-  tar xf source/binutils-2.36.tar.xz -C work/
-fi
 
 #---------------------------------------------
 #
 # 编译源码 
 #
 #---------------------------------------------
-cd work
+cd ${build_dir}
 
 # 编译内核, 最终所有模块都装到目录 /lib/modules/4.14.9
-if [ ! -d "kernel_install" ]; then 
-  mkdir -pv kernel_install && cd linux-4.14.9 && make mrproper && make x86_64_defconfig
+if [ ! -d "linux_install" ]; then 
+  mkdir -pv linux_install && cd ${LINUX_SRC_DIR} && make mrproper && make x86_64_defconfig
   # Enable the VESA framebuffer for graphics support.
   sed -i "s/.*CONFIG_FB_VESA.*/CONFIG_FB_VESA=y/" .config 
   # 网络需要 TUN/TAP 驱动 [ Device Drivers ] ---> [ Network device support ] ---> [ Universal TUN/TAP device driver support ]
   make bzImage -j8
   #cd linux-4.14.9 && make x86_64_defconfig && make bzImage -j8 && make modules && make modules_install && cd ..
-  make INSTALL_HDR_PATH=${kernel_install} headers_install -j8 && cp arch/x86_64/boot/bzImage ${kernel_install} && cd ..
+  make INSTALL_HDR_PATH=${linux_install} headers_install -j8 && cp arch/x86_64/boot/bzImage ${linux_install} && cd ..
 fi
 
 # 编译glibc
 if [ ! -d "glibc_install" ]; then
-  mkdir -pv glibc_install && cd glibc-2.32
+  mkdir -pv glibc_install && cd ${GLIBC_SRC_DIR}
   mkdir -pv build && cd build && make distclean
   ../configure --prefix=/usr \
-    --with-headers=${kernel_install}/include \
+    --with-headers=${linux_install}/include \
     --enable-kernel=4.0.1 \
     --without-selinux \
     --disable-werror \
@@ -160,24 +172,24 @@ fi
 
 # 编译 busybox 
 if [ ! -d "busybox_install" ]; then
-  mkdir -pv busybox_install && cd busybox-1.34.1 && make distclean && make defconfig
+  mkdir -pv busybox_install && cd ${BUSYBOX_SRC_DIR} && make distclean && make defconfig
   # 静态编译 sed -i "s/# CONFIG_STATIC is not set/CONFIG_STATIC=y/g" .config
   sed -i "s|.*CONFIG_SYSROOT.*|CONFIG_SYSROOT=\"${glibc_install}\"|" .config
-  sed -i "s|.*CONFIG_EXTRA_CFLAGS.*|CONFIG_EXTRA_CFLAGS=\"-I${kernel_install}/include -I${glibc_install}/include -L${glibc_install}/usr/lib64 $CFLAGS\"|" .config
+  sed -i "s|.*CONFIG_EXTRA_CFLAGS.*|CONFIG_EXTRA_CFLAGS=\"-I${linux_install}/include -I${glibc_install}/include -L${glibc_install}/usr/lib64 $CFLAGS\"|" .config
   make busybox -j8 && make CONFIG_PREFIX=${busybox_install} install && cd ..
 fi
 
-# 编译 libgcc
-if [ ! -d "libgcc_install" ]; then 
-  mkdir -pv libgcc_install && cd gcc-7.5.0 && make distclean && rm ./config.cache
+# 编译 gcc
+if [ ! -d "gcc_install" ]; then 
+  mkdir -pv gcc_install && cd ${GCC_SRC_DIR} && make distclean && rm ./config.cache
   ./contrib/download_prerequisites
   ./configure --prefix=/usr --enable-languages=c,c++ --disable-multilib --disable-static --disable-libquadmath --enable-shared
-  CFLAGS="-L${glibc_install}/lib64 $CFLAGS" make -j8 && make install -j8 DESTDIR=${libgcc_install} && cd ..
+  CFLAGS="-L${glibc_install}/lib64 $CFLAGS" make -j8 && make install -j8 DESTDIR=${gcc_install} && cd ..
 fi
 
 # 编译 binutils
 if [ ! -d "binutils_install" ]; then
-  mkdir -pv binutils_install && cd binutils-2.36 && make distclean
+  mkdir -pv binutils_install && cd ${BINUTILS_SRC_DIR} && make distclean
   ./configure --prefix=/usr
   CFLAGS="-L${glibc_install}/lib64 $CFLAGS" make -j8 && make install -j8 DESTDIR=${binutils_install} && cd ..
   cd ..
diff --git a/02_build_img.sh b/02_build_img.sh
index 146f690..bcef7a3 100755
--- a/02_build_img.sh
+++ b/02_build_img.sh
@@ -15,8 +15,8 @@ CYAN='\e[1;36m'
 WHITE='\e[1;37m' # 白色
 NC='\e[0m' # 没有颜色
 
-# ./02_build_img.sh gcc 这样就能编译带 gcc 的系统
-with_gcc=$1
+# 导入公共环境
+. ./common.sh
 
 #----------------------------------------------
 #
@@ -32,7 +32,7 @@ with_gcc=$1
 #----------------------------------------------
 echo "${CYAN}--- build disk --- ${NC}"
 # 创建磁盘 64M
-if [ ! -n "${with_gcc}" ]; then
+if [ "${with_gcc}" = false ]; then
   dd if=/dev/zero of=disk.img bs=1M count=128
 else
   dd if=/dev/zero of=disk.img bs=1M count=256
@@ -82,30 +82,30 @@ mkdir -pv rootfs/lib64
 mkdir -pv rootfs/lib/modules
 
 # 拷贝内核镜像
-cp work/kernel_install/bzImage ${diskfs}/boot/bzImage
+cp ${linux_install}/bzImage ${diskfs}/boot/bzImage
 
 # 拷贝 glibc 到 rootfs
-cp work/glibc_install/* rootfs/ -r
+cp ${glibc_install}/* rootfs/ -r
 rm -rf rootfs/var/db 
 rm -rf rootfs/share
 rm -rf rootfs/usr/share
 find rootfs/ -name "*.a" -exec rm -rf {} \;
 # 编译的镜像带有 gcc 编译器
-if [ ! -n "${with_gcc}" ]; then
-  echo "without-gcc tools."
- #rm -rf rootfs/include
+if [ "${with_gcc}" = false ]; then
+  rm -rf rootfs/usr/include
 else
   echo "${RED} with-gcc tools --- you can build your world${NC}"
-  cp work/glibc_install/usr/lib64/libc_nonshared.a rootfs/usr/lib64 
+  cp ${glibc_install}/usr/lib64/libc_nonshared.a rootfs/usr/lib64 
 fi
 
 #----------------------------------------------------------------------
 # 这个解释器必须设置对，否则系统会启动时 crash, 导致启动失败 !!!!!!
+# 这个现在 glibc 编译时，已经自动生成，先注释掉
 #-----------------------------------------------------------------------
-ln -s /lib/ld-2.32.so rootfs/lib64/ld-linux-x86-64.so.2
+# ln -s /lib/ld-2.32.so rootfs/lib64/ld-linux-x86-64.so.2
 
 # 拷贝 busybox 到 rootfs
-cp work/busybox_install/* rootfs/ -r
+cp ${busybox_install}/* rootfs/ -r
 
 #-----------------------------------------------
 #
@@ -122,7 +122,6 @@ make_init() {
 
 cat<<"EOF">init
 #!/bin/sh
-
 # 必须首先挂载，否则 mdev 不能正常工作
 mount -t sysfs none /sys
 mount -t proc none /proc
@@ -131,21 +130,19 @@ mount -t tmpfs none /tmp -o mode=1777
 # 必须挂载一下，否则下面的 mount 不上
 mdev -s
 mount -t ext3 /dev/sda1 /mnt
-
 # 关闭内核烦人的输出信息
 echo 0 > /proc/sys/kernel/printk
+# 热插拔处理都交给 mdev
+echo /sbin/mdev > /proc/sys/kernel/hotplug
 echo -e "\n\e[0;32mBoot took $(cut -d' ' -f1 /proc/uptime) seconds\e[0m"
-
 mkdir -p /dev/pts
 mount -t devpts none /dev/pts
-
 # 切换之前，修改 mount 路径
 mount --move /dev /mnt/dev
 mount --move /sys /mnt/sys
 mount --move /proc /mnt/proc
 mount --move /tmp /mnt/tmp
-
-# 切换到真正的磁盘系统上 rootfs(initramfs) ---> diskfs
+# 切换到真正的磁盘系统上 rootfs ---> diskfs
 exec switch_root /mnt /sbin/init
 EOF
 
@@ -192,17 +189,17 @@ cd ..
 echo "${CYAN}--- build diskfs ---${NC}"
 cp rootfs/* ${diskfs} -r
 # 带有 gcc 编译器
-if [ "${with_gcc}" ]; then
+if [ "${with_gcc}" = true ]; then
   echo "${RED} with-gcc tools --- you can build your world${NC}"
-  cp work/libgcc_install/* ${diskfs} -r
-  cp work/binutils_install/usr/x86_64-pc-linux-gnu/* ${diskfs} -r
+  cp ${gcc_install}/* ${diskfs} -r
+  cp ${binutils_install}/usr/x86_64-pc-linux-gnu/* ${diskfs} -r
 fi
 rm -rf ${diskfs}/init ${diskfs}/lost+found
 
 # 我们测试驱动, 制作的镜像启动后，我们进入此目录 insmod hello_world.ko 即可 
 ./mk_drv.sh $(pwd)/${diskfs}/lib/modules 
 # 编译网卡驱动 ( 目前版本内核已集成 e1000 )
-# cd work/linux-4.14.9 && make M=drivers/net/ethernet/intel/e1000/ && cd ../..
+# cd ${build_dir}/linux-4.14.9 && make M=drivers/net/ethernet/intel/e1000/ && cd ../..
 
 # 生成 grub.cfg 文件, 增加 console=ttyS0 就会让 qemu 输出日志到 qemu.log
 cat - > ${diskfs}/boot/grub/grub.cfg << EOF
diff --git a/common.sh b/common.sh
new file mode 100755
index 0000000..e16ec7d
--- /dev/null
+++ b/common.sh
@@ -0,0 +1,30 @@
+# 处理器
+core_num=`nproc`
+
+# 是否开启 gcc
+with_gcc=false
+
+# 编译工程目录
+build_dir=`pwd`"/build"
+
+# 公共目录
+linux_install=${build_dir}"/linux_install"
+glibc_install=${build_dir}"/glibc_install"
+busybox_install=${build_dir}"/busybox_install"
+gcc_install=${build_dir}"/gcc_install"
+binutils_install=${build_dir}"/binutils_install"
+
+# 从完整路径获取文件名
+file_name() {
+  filename=$(echo $1 | rev | awk -v FS='/' '{print $1}' | rev)
+  echo ${filename}
+}
+
+# 获取去掉扩展名的文件名
+file_dirname() {
+  filename=$(file_name $1)
+  filedir=`echo $filename | sed "s/$2//g"`
+  echo $filedir
+}
+
+
diff --git a/mk_drv.sh b/mk_drv.sh
index f02bef9..9334d1c 100755
--- a/mk_drv.sh
+++ b/mk_drv.sh
@@ -27,9 +27,9 @@ EOF
 cat<<EOF>Makefile
 obj-m += hello_world.o
 all:
-	make -C ../work/linux-4.14.9 M=`pwd` modules
+	make -C ../build/linux-4.14.9 M=`pwd` modules
 clean:
-	make -C ../work/linux-4.14.9 M=`pwd` clean
+	make -C ../build/linux-4.14.9 M=`pwd` clean
 EOF
 
 echo $1
diff --git a/mk_strip.sh b/mk_strip.sh
index 8d2b68e..a1be920 100755
--- a/mk_strip.sh
+++ b/mk_strip.sh
@@ -1,5 +1,8 @@
 #!/bin/sh
 
+# 导入公共环境
+. ./common.sh
+
 strip_dir() {
   for file in `ls $1`
   do
@@ -24,18 +27,18 @@ strip_dir() {
 }
 
 # strip glibc
-rm -rf work/glibc_install/usr/share
-strip_dir work/glibc_install 
+rm -rf ${glibc_install}/usr/share
+strip_dir ${glibc_install}
 
 # strip busybox
-rm -rf work/busybox_install/linuxrc
-strip work/busybox_install/bin/busybox 
+rm -rf ${busybox_install}/linuxrc
+strip ${busybox_install}/bin/busybox 
 
 # strip gcc
 #rm -rf work/libgcc_install/usr/share
-strip_dir work/libgcc_install
+strip_dir ${gcc_install}
 
 # strip binutils
 #rm -rf work/binutils_install/usr/share
-strip_dir work/binutils_install
+strip_dir ${binutils_install}