OpenOCD 与 GDB

说明

本页汇总 OpenOCD 的安装配置, 常用命令和与 GDB 联动的调试记录.
适用于嵌入式烧录, 远程调试和板级 Bring-up 场景.

openocd 编译安装

sudo apt install libusb-1.0-0-dev

git clone https://github.com/ntfreak/openocd.git

编译
    ./bootstrap
    ./configure
    make -j
    sudo make install

vscode 调试 openocd 本身， 编译：
    export CFLAGS="-O0"
    ./bootstrap
    ./configure --prefix=/develop/sources/openocd/output
    make -j
    make install

配置：
    {
        "type": "lldb",
        "request": "launch",
        "name": "debug openocd",
        "program": "${workspaceFolder}/output/bin/openocd",
        "args": ["-f", "board/stm32h750b-disco.cfg"],
        "cwd": "${workspaceFolder}"
    },

openocd调试stm32f7

openocd -f board/stm32f7discovery.cfg

在linux中当前用户执行openocd，报错: unable to open CMSIS-DAP device 0xc251:0xf001

sudo vim /etc/udev/rules.d/cmsis-dap.rules, 添加一下内容(记得更改组):
    ATTRS{idVendor}=="c251", ATTRS{idProduct}=="f001", MODE="664", GROUP="maxu"

sudo udevadm control --reload

常用命令

openocd -f interface/cmsis-dap.cfg -f target/stm32h7x.cfg, 使用cmsis-dap调试stm32h750

openocd -f board/stm32f7discovery.cfg

telnet localhost 4444

program <filename> [address] [verify] [reset] [exit], 写可执行程序到flash上, 只有binary images才需要address

    ex: program output.bin 0x08000000 reset; halt; reg; resume; exit

halt, 进入挂起状态

reg [REG [value]] , 查看或设置寄存器, 可能需要在halt状态下

resume, 恢复到当前代码段

reset [run|halt|init], 重置, 进入特定状态, 默认是run

reg, 查看寄存器内容, 在halt状态下才会显示内容

targets, 显示所有目标

使用gdb和openocd实现远程下载

arm-none-eabi-gdb -q --readnow -ex "target extended-remote 3333" -ex "b main" -ex "monitor halt" -ex "load" -ex "c" -ex "monitor resume" -ex "echo ok\n" -ex "disconnect" -ex "q"
为了远程的下载程序到sram中, 我发现用gdb在load后自动设置的pc, 用i r看是对的, 用'continue'是可以的, 但是阻塞的, 用了'monitor resume', 但是用monitor reg pc查看pc, 却是每2次中1对1错, 很有规律,,,,,,,,,,用上面的命令: 先给程序加断点,'c', 自动走到断点处, 执行'monitor resume', 退出, 就解决了

openocd实现重启到指定地址

gcc 编译选项:
LDFLAGS += -Wl,-Map=output.map

openocd -f board/stm32f7discovery.cfg -c "program output.bin ${flash_to_addr} reset; halt; reg pc ${reset_entry}; resume; exit"

openocd 用法

如果你的设备支持openocd调试, 那么调试器连接上PC, 在PC上运行openocd, 就作为一个Server, 可调式, 可烧写

下面两种方法的过程都是一样的: 1. load image 2. 打印向量表的位置, 要显示2个字 3. 挂起状态 4. 设置sp指针, 设置pc指针 5. 恢复

向量表的地址, 符号在startup.s中, 根据符号在map文件中找到具体的地址

gdb 连接 openocd, 使用记录

调试文件需要在开发机上

(gdb) target remote 10.239.71.34:3333
Remote debugging using 10.239.71.34:3333
0x7000dd5a in ?? ()
(gdb) load app.elf
Loading section text, size 0x1e8 lma 0x60000000
Loading section text_2, size 0x1e14e lma 0x600001e8
Loading section .ARM.exidx, size 0x8 lma 0x6001e338
Loading section sw_isr_table, size 0x350 lma 0x6001e340
Loading section devconfig, size 0x294 lma 0x6001e690
Loading section shell_root_cmds_sections, size 0xc0 lma 0x6001e924
Loading section rodata, size 0x2161c lma 0x6001e9e4
Loading section datas, size 0x2079 lma 0x60050498
Loading section initlevel, size 0x194 lma 0x60052514
Loading section _static_thread_area, size 0x60 lma 0x600526a8
Loading section _k_mem_slab_area, size 0x54 lma 0x60052708
Loading section _k_mem_pool_area, size 0x1c lma 0x6005275c
Loading section _k_sem_area, size 0x168 lma 0x60052778
Loading section _k_mutex_area, size 0xc8 lma 0x600528e0
Loading section _k_queue_area, size 0x14 lma 0x600529a8
Start address 0x60011690, load size 271647
Transfer rate: 34 KB/sec, 9054 bytes/write.
(gdb) x/2xw 0x60000000
0x60000000 <_vector_table>:	0x6004e5a0	0x60011691
(gdb) set $pc=0x60011691
(gdb) set $sp=0x6004e5a0
(gdb) c
Continuing.

telnet连接openocd 使用记录

用telnet这种办法是远程操作, 调试文件需要在远程, 文件路径是启动openocd时的路径

mx@maxu-pc:/data$ telnet 10.239.71.34 4444

Trying 10.239.71.34...
Connected to 10.239.71.34.
Escape character is '^]'.
Open On-Chip Debugger
>
> load_image ./bin/app.elf
456784 bytes written at address 0x60000000
5368 bytes written at address 0x6006f850
downloaded 462152 bytes in 13.153211s (34.313 KiB/s)
>
> halt
>
> targets
    TargetName         Type       Endian TapName            State
--  ------------------ ---------- ------ ------------------ ------------
0* ose.cpu            cortex_m   little ose.cpu            halted
>
>
> ose.cpu mdw 0x60000000 2
0x60000000 60100000 600004b5                   ...`...`
> reg sp 0x60100000
sp (/32): 0x60100000
> reg pc 0x600004b5
pc (/32): 0x600004B5
>
> resume

关于"ose.cpu mdw", 这样内存读写命令, 可以通过"help mem"的形式搜索, 有很多类似的命令, 都可以实现查看内存

自定义proc

stmh7_cmsis.cfg:

    source [find interface/cmsis-dap.cfg]

    transport select swd

    source [find target/stm32h7x.cfg]

    proc flash () {
        init
        halt
        flash write_image erase rtthread.bin 0x08000000
        reset run
        shutdown
    }

使用:
    openocd -f stmh7_cmsis.cfg -c "flash ()"

使用 cmsisdap 调试 stm32

choco install make openocd gcc-arm-embedded

创建文件 dap-stm32.cfg, 添加以下内容:

    interface cmsis-dap
    transport select swd
    source [find target/stm32f1x.cfg]

烧写程序:
    openocd -f ocd-stm32.cfg -c "program build/stm32f103rct6.bin 0x8000000 reset exit"

打开 launch.json, 新添加一项调试配置:

{
	"name": "Cortex Debug",
	"cwd": "${workspaceRoot}",
	"executable": "build/stm32f103rct6.elf",
	"request": "launch",
	"type": "cortex-debug",
	"servertype": "openocd",
	"configFiles": [
		"dap-stm32.cfg"
	]
}

必要时, 可以添加 armToolchainPath, 但是 openocd 的路径好像不能添加, 只能设置环境变量

arm-none-eabi-gdb

info target
info mem 显示内存情况， 包括 ROM 和 RAM

where 显示当前程序执行位置

monitor target
monitor targets

monitor flash banks 查看 flash

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