GDB（GNU Project Debugger）是在Linux環境下功能全面的調試工具。它提供了一系列強大的調試功能，包括設置斷點、單步執行、打印與觀察變量、查看寄存器及堆棧信息等。在Linux軟件開發的實踐中，GDB被視為調試C及C++程序的核心工具，廣泛用于幫助開發者定位和解決程序中的問題。

1. 虛擬機中安裝GDB工具

為避免符號解析錯誤或架構不兼容問題，用于遠程調試的GDB應在版本上與開發板的工具鏈對齊。

elf@ubuntu:~/work/EDU/sdk/ELF2-linux-source$ ./build.sh bconfig

路徑：

->Toolchain

選擇GDB版本，這里選擇gdb12.x

2. 文件系統添加gdbserver功能

elf@ubuntu:~/work/EDU/sdk/ELF2-linux-source$./build.sh bconfig

路徑：

-> Target packages -> Debugging, profiling and benchmark

3. 重新編譯

elf@ubuntu:~/work/EDU/sdk/ELF2-linux-source$./build.sh buildroot

這樣就可以將軟件包直接編譯到文件系統的鏡像中了。

4. 燒寫文件系統

5. 應用編譯及拷貝

elf@ubuntu:~/work$vi gdbdemo.c

例程代碼如下：

#include int main() { int a = 10; int b = 20; int sum = a + b; printf("a = %d, b = %d\n", a, b); printf("sum = %d\n", sum); for (int i = 0; i < 5; i++) { printf("Loop i = %d\n", i); } return 0; }

添加交叉編譯器路徑，進行交叉編譯，編譯要調試的應用程序：必須要加-g選項

elf@ubuntu:~/work$ export PATH=/home/elf/aarch64-buildroot-linux-gnu_sdk-buildroot/bin/:$PATH elf@ubuntu:~/work$ aarch64-linux-gcc -g gdbdemo.c -o gdbdemo

將編譯生成的gdbdemo通過U盤拷貝到開發板上，比如/home/elf路徑下，下述以U盤為例，拷貝到開發板。

root@elf2-buildroot:~#cp/mnt/udisk/gdbdemo /home/elf

6. 設置開發板IP和端口號

root@elf2-buildroot:~# gdbserver 172.20.8.7:2345 /home/elf/gdbdemo Process /home/elf/gdbdemo created; pid = 1314 Listening on port 2345

7. 給虛擬機設置同網段的IP并保證可以ping通開發板IP

8. 調試

GDB工具所在路徑：

ELF2-linux-source/buildroot/output/elf2_fs/host/bin/aarch64-linux-gdb

elf@ubuntu:~/work$ ./EDU/sdk/ELF2-linux-source/buildroot/output/elf2_fs/host/bin/aarch64-linux-gdb gdbdemo GNU gdb (GDB) 12.1 Copyright (C) 2022 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "--host=x86_64-pc-linux-gnu --target=aarch64-buildroot-linux-gnu". Type "show configuration" for configuration details. For bug reporting instructions, please see: . Find the GDB manual and other documentation resources online at: . For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from gdbdemo... (gdb) target remote 172.20.8.7:2345 //連接開發板 Remote debugging using 172.20.8.7:2345 Reading /lib/ld-linux-aarch64.so.1 from remote target... warning: File transfers from remote targets can be slow. Use "set sysroot" to access files locally instead. Reading /lib/ld-linux-aarch64.so.1 from remote target... Reading symbols from target:/lib/ld-linux-aarch64.so.1... (No debugging symbols found in target:/lib/ld-linux-aarch64.so.1) Reading /home/elf/work/EDU/sdk/ELF2-linux-source/buildroot/output/elf2_fs/host/lib/debug/.build-id/01/bd8db25550e790a84285a6377baa031748d93c.debug from remote target... 0x0000007ff7ff1900 in _start () from target:/lib/ld-linux-aarch64.so.1 (gdb)

此時就可以根據需求進行調試了，下面是幾個常用的命令

（1）l：列出所有源代碼

（2）b：設置斷點

（3）c：運行到斷點處

（4）s：單步運行執行

（5）n：單步執行，但是step會進入函數里面，但是next不會

（6）p a：打印a這個變量的值

（7）q：退出，輸入此命令則開發板上的gdbserver也退出

下面以具體示例介紹參數的使用方法。

(gdb) l //列出源代碼 1 #include 2 3int main() { 4 int a = 10; 5 int b = 20; 6 int sum = a + b; 7 8 printf("a = %d, b = %d\n", a, b); 9 printf("sum = %d\n", sum); 10 (gdb) b 9 //在第9行設置斷點 Breakpoint 1 at 0x55555557d0: file gdbdemo.c, line 9. (gdb) c // 繼續執行程序，直到遇到斷點，此時終端打印a = 10, b = 20 Continuing. Reading /lib/libc.so.6 from remote target... Breakpoint 1, main () at gdbdemo.c:9 9 printf("sum = %d\n", sum); (gdb) c //從當前斷點繼續執行到程序結束。 Continuing. [Inferior 1 (process 1367) exited normally] (gdb)