基于VS Code的Linux内核调试环境搭建及start_kernel跟踪分析

下载Linux内核源码并编译

wget https://raw.github.com/mengning/mykernel/master/mykernel-2.0_for_linux-5.4.34.patch
sudo apt install axel
axel -n 20 https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/linux-5.4.34.tar.xz
xz -d linux-5.4.34.tar.xz
tar -xvf linux-5.4.34.tar
cd linux-5.4.34
patch -p1 < ../mykernel-2.0_for_linux-5.4.34.patch
sudo apt install build-essential libncurses-dev bison flex libssl-dev libelf-dev
make -j$(nproc) # 编译的时间比较久哦
sudo apt install qemu # install QEMU
qemu-system-x86_64 -kernel arch/x86/boot/bzImage

当quemu成功启动编译后的内核文件时，从qemu窗口中可以看到my_start_kernel在执行，同时my_timer_handler时钟中断处理程序周期性执行。

其中需要配置编译选项

make defconfig # Default configuration is based on 'x86_64_defconfig'
make menuconfig# 打开debug相关选项

Kernel hacking --->
Compile-time checks and compiler options --->
[*] Compile the kernel with debug info
[*] Provide GDB scripts for kernel debugging
[*] Kernel debugging
# 关闭KASLR（随机地址），否则会导致打断点失败。这样调试器就可以跟踪到源代码，之所以设置随机地址为了防止黑客攻击:
Processor type and features ---->
[ ] Randomize the address of the kernel image (KASLR)

qemu成功启动内核