Debug Linux Kernel Environment build method (ddd+busybox+qemu+linux3.5.4 kernel)

Environment construction

1.1. Preparatory work

(1). QEMU Virtual Machine

(2). BusyBox Software

(3). linux-3.5.4 kernel

(4). DDD Debug tool (in Terminal input sudo apt-get install DDD installation)

1.2. Compiling the kernel

(1) Establishment of working directory: Mkdir-p ~/work/qemu

(2) switch to this directory: CD ~/work/qemu

(3) Download Linux kernel

(4) Decompression core: TAR-JXVF linux-3.5.4.tar.bz2

(5) Switch to linux-3.5.4 directory: CD linux-3.5.4

(6) Configure compilation options: Makemenuconfig

Description: May be missing dependent package Ncurses-dev input: sudo apt-get install ncurses-dev Some versions of Linux source may be: sudo apt-get install Libncurses5-dev

The compile options are selected:

Kernelhacking–>kerneldebugging–> compile the kernel with debug info

Kernelhacking–> compilethe kernel with frame pointers

(7) Compile: Make (note: Do not install the kernel after compiling, if there are errors when compiling, please check if there are fewer compile tools installed)

(8) Copy the file Bzimage to the parent directory: CP Arch/x86/boot/bzimage. /

1.3. Installing the QEMU virtual machine

(1) Download the QEMU installation file

(2) Install the library file before you install QEMU. Open Terminal input sudo apt-get install gcc libsdl1.2-dev zlib1g-dev libasound2-devpkg-config libgnutls-dev Pciutils-dev

(3) switch to the QEMU source directory input./configure Generate makefile

(4) Enter make to start compiling (if Automake package is missing, enter sudo apt-get install autoconf automake libtool installation)

(5) Enter sudo make install to start installation

1.4. Making the root file system

(1) Switch directory: CD ~/WORK/QEMU

(2) Create size 10M to root filesystem: DD If=/dev/zero of=rootfs.img bs=1m count=10

(3) Format the root file with the ext3 type: Mkfs.ext3 rootfs.img

(4) Create rootfs directory: mkdir rootfs

(5) Mount the rootfs.img to the Rootfs directory: sudo mount-t ext3-o loop rootfs.img rootfs

(6) Switch to ROOTFS directory: CD rootfs

(7) Creation of three directories: mkdir DEV proc Sys

1.5. Install BusyBox to the root file system

(1) Download BusyBox

(2) Unzip, switch to BusyBox source directory, configure busybox compile option: Make Menuconfig

A. Select static compilation : Busyboxsettings->build Options->buildbusybox as a static binary

B. Cancellation of Networkingutilities->iptunel

C. Cancellation of networkingutilities->inetd

(2) Compile: Make

(3) Install the BusyBox file system into the root file system you just created: Make install Config_prefix=~/work/qemu/rootfs

(4) Switch to QEMU directory: CD ~/work/qemu

(5) Uninstalling the root file system: sudo umount rootfs

1.6. Verification process

(1) Write C validator in ~/work directory TEST_FORK.C

#include <unistd.h>

#include <sys/types.h>

int main ()

{

pid_t pid;

Pid=fork ();

}

(2) Compiling C program

Gcc-c-G-STATICTEST_FORK.C

Gcc-o test_fork-static TEST_FORK.O

Because BusyBox is compiled into static, the C program can be run in the QEMU virtual machine and must be compiled to static. This allows the Test_frok command to run in the virtual machine

(3) Enter the sudo mount-t ext3-o loop rootfs.img rootfs command to mount the root file system of the QEMU virtual machine.

(4) Enter the CP Fork rootfs/bin command to test the fork into the bin/folder of the root file system

(5) Uninstalling the root file system: sudo umount rootfs

(6) Start QEMU

A. Open terminal input, input command switch to ~/WORK/QEMU directory: CD ~/work/qemu

B. Enter qemu-system-i386-s-kernel bzimage-hda rootfs.img-append "Root=/dev/sdainit=/bin/ash rw"-monitor stdio start Qemu (64-bit Computer Please change i386 to x86)

Note: RW represents an open virtual machine that can be read and written.

-monitor stdio means that the console in QEMU is transferred to the terminal without ctrl+alt+2 switching

C. Enter "Gdbserver tcp::1234" in console

D. Open another terminal, enter the command CD ~/work/qemu/linux-3.5.4 switch to the ~/misc/qemu/linux-3.5.4 directory

E. Running Dddvmlinux (no ddd input sudo apt-get installddd installation)

F. Enter commands in the DDD Command Window target remote localhost:1234 connect the QEMU virtual machine to the console of the DDD

G. Enter B do_fork the command window in DDD to add a breakpoint on the Do_fork function

H. Enter in the command window of DDD to have the virtual machine continue execution

(7) Enter the Test_fork command in the QEMU virtual machine terminal so that the kernel is interrupted at the Do_fork function. You can debug this function in a variety of ways.

Do not understand can give me a message.