用Qemu运行/调试arm linux

用Qemu运行/调试arm linux

用Qemu运行/调试arm linux，这事情干过好几次了，久了就忘记了，每次都要重新去查资料，浪费不少时间。这次把整个过程弄成个脚本，放到github上，需要是拿下来运行一下即可，方便自己也方便有需要的朋友。这里解释一下脚本的内容(运行系统Ubuntu 16.04 LTS)：

1. 设置一些环境变量，可以根据自己需要修改。

export ARCH=arm
export MACHINE=vexpress
export TARGET=arm-linux
export GDB_VERSION=8.0
export KERNEL_VERSION=4.4.1
export BUSYBOX_VERSION=1.25.1
export CROSS_COMPILE=arm-linux-gnueabihf-

2. 安装工具链等软件包

function prepare() {
  apt-get -y install qemu gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf libexpat1-dev libncurses5-dev
}

3. 下载Linux内核并解压

function download_linux() {
  if [ -e linux-${KERNEL_VERSION}.tar.xz ]
  then
    echo linux-${KERNEL_VERSION}.tar.xz exist
  else
    wget https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-${KERNEL_VERSION}.tar.xz
  fi

  if [ -e linux-${KERNEL_VERSION} ]
  then
    echo linux-${KERNEL_VERSION} exist
  else
    tar xf linux-${KERNEL_VERSION}.tar.xz
  fi
}

4. 编译Linux内核

function build_linux() {
  echo "build_linux ..."
  cd linux-${KERNEL_VERSION}
  make ${MACHINE}_defconfig
  make zImage -j8
  make modules -j8
  make dtbs
  cd -
}

5. 拷贝内核到独立目录

function copy_linux() {
  rm -rf arm-linux-kernel
  mkdir arm-linux-kernel
  cp -fv linux-${KERNEL_VERSION}/arch/arm/boot/zImage arm-linux-kernel/
  cp -fv linux-${KERNEL_VERSION}/arch/arm/boot/dts/*ca9.dtb arm-linux-kernel/
  cp -fv linux-${KERNEL_VERSION}/.config  arm-linux-kernel/
}

6. 下载并解压busybox

function download_busybox() {
  if [ -e busybox-${BUSYBOX_VERSION}.tar.bz2 ]
  then
    echo busybox-${BUSYBOX_VERSION}.tar.bz2 exist
  else
    wget https://busybox.net/downloads/busybox-${BUSYBOX_VERSION}.tar.bz2
  fi

  if [ -e busybox-${BUSYBOX_VERSION} ]
  then
    echo busybox-${BUSYBOX_VERSION} exist
  else
    tar xf busybox-${BUSYBOX_VERSION}.tar.bz2
  fi
}

7. 编译busybox

function build_busybox() {
  echo "build_busybox..."
  cd busybox-${BUSYBOX_VERSION}
  make defconfig
  make CROSS_COMPILE=${CROSS_COMPILE}
  make install CROSS_COMPILE=${CROSS_COMPILE}
  cd -
}

8. 制作rootfs

function make_rootfs() {
 rm -rf tmpdir
 rm -rf rootfs
 mkdir -p rootfs/lib
 mkdir -p rootfs/dev

 cp -Pvf /usr/arm-linux-gnueabihf/lib/* rootfs/lib
 cp busybox-${BUSYBOX_VERSION}/_install/* rootfs/ -rf

 dd if=/dev/zero of=rootfs.ext3 bs=1M count=128
 mkfs.ext3 rootfs.ext3

 mkdir tmpdir
 mount -t ext3 rootfs.ext3 tmpdir/ -o loop
 cp -r rootfs/*  tmpdir/
 mknod tmpdir/dev/tty1 c 4 1
 mknod tmpdir/dev/tty2 c 4 2
 mknod tmpdir/dev/tty3 c 4 3
 mknod tmpdir/dev/tty4 c 4 4
 umount tmpdir
}

9. 下载并解压gdb

function download_gdb() {
  if [ -e gdb-${GDB_VERSION}.tar.gz ]
  then
    echo gdb-${GDB_VERSION}.tar.gz exist
  else
    wget http://ftp.gnu.org/gnu/gdb/gdb-${GDB_VERSION}.tar.gz
  fi

  if [ -e gdb-${GDB_VERSION} ]
  then
    echo gdb-${GDB_VERSION} exist
  else
    tar xf gdb-${GDB_VERSION}.tar.gz
  fi
}

10. 编译gdb

function build_gdb() {
  echo "build_gdb..."
  cd gdb-${GDB_VERSION}
  ./configure --target=${TARGET} --enable-sim --prefix=/usr/local/
  make
  cp -fv gdb-${GDB_VERSION}/gdb/gdb /usr/local/bin/arm-linux-gdb
  cd -
}

11. 生成gdb启动脚本

function gen_gdb_init() {
  echo "file linux-${KERNEL_VERSION}/vmlinux" >gdbinit
  echo "dir linux-${KERNEL_VERSION}" >>gdbinit
  echo "target remote :1234" >>gdbinit
}

12. 汇总

function build() {
  prepare
  download_linux
  build_linux
  copy_linux
  download_busybox
  build_busybox
  make_rootfs
  download_gdb
  build_gdb
  gen_gdb_init
}

build

echo "Done"

github

还包括其它一些脚本和使用说明，一并放在https://github.com/xianjimli/qemu-arm-linux上。

参考资料（非常感谢）

• http://files.meetup.com/1590495/debugging-with-qemu.pdf
• http://blog.csdn.net/nxcxl88/article/details/53244754