Introduction to GDB

GDB is a powerful program debugging tool under UNIX released by the GNU open source organization.

GDB porting

method 1:

If ubuntu has installed a cross compiler (normally it must be installed), then it has integrated its own gdb, just copy gdbserver to the specified directory /bin/ of the development board file system

Test gdb related information

Method 2:

This is more troublesome, you need to obtain the source code of gdb and gdbserver from the official website, the path address: Download GDB (sourceware.org)

Unzip and compile steps:

tar -vxzf gdb-9.1.tar.gz  //Generate gdb-9.1 after decompression
cd gdb-9.1 
mkdir build  //You need to create a new build directory under gdb
cd build
../configure --target=arm-linux-gnueabihf --prefix=/home/l17/tool/gdb
make //compile
make install //Install

Problems may arise:

gdb-9.1/missing: makeinfo: not found
...
Makefile:490: recipe for target 'gdb.info' failed
make[4]: *** [gdb.info] Error 127
...
Makefile:2006: recipe for target 'subdir_do' failed
make[3]: *** [subdir_do] Error 1
...
Makefile:851: recipe for target 'all' failed
make: *** [all] Error 2

Solution:

sudo apt install texinfo

Cross-compile gdbserver. After executing the following command, gdbserver will be generated. Copy gdbserver to the specified directory /bin/ of the development board file system (recommended method 1)

cd gdb-9.1/gdb/gdbserver  //Go to the gdbserver directory
./configure --target=arm-linux-gnueabihf --host=arm-linux-gnueabihf
make CC=arm-linux-gnueabihf-gcc  //Cross compile gdbserver

add environment variable

After the configuration is complete, you need to enter ubuntu's /etc/profile to modify the environment variables

Method 1: Because the toolchain is installed, no modification is usually required
export PATH=/usr/local/arm/gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabihf/bin:$PATH
 Method 2: Determine the current
export PATH=/usr/local/arm/gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabihf/bin:/home/
l17/tool/gdb/bin:$PATH

debug test

Write a simple application

/**************************************Start of file************************************/




/*--------------------------------------------------------------------------------------
Includes
*/
 #include <stdio.h>
 #include <unistd.h>

 int main(int argc, char *argv[])
 {
    unsigned int timerCnt = 0;

    while(1) 
    {
        printf("system runing times:%d\r\n", timerCnt);
        timerCnt++;
        sleep(1);
    }
}

/****************************************End of file************************************/

• ubuntu cross compile gdbApp.c output executable file

arm-linux-gnueabihf-gcc gdbApp.c -o gdbApp -g

• Copy the executable file to the development board (file system nfs)

cp gdbApp /home/l17/nfs/rootfs/

• Start the development board and execute the gdb service command (enter the debugging host, which is the ubuntu ip address)

gdbserver 192.168.0.67:2001 gdbApp //Start gdbserver on the development board

• ubuntu starts gdb to debug the specified code

arm-linux-gnueabihf-gdb gdbApp

• Enter the following command in the gdb window to connect to the debugging device (you need to know the ip address of the debugging device)

target remote 192.168.0.50:2001

Use gdb related commands to perform debugging work (specifically, Baidu)

• l command, wipe the source code
• b command, set debug breakpoints
• c command, execute the next breakpoint
• q command to quit debugging

Debugging based on VSCode interface

• New folder: .vscode, New file: launch.json

• Run -> Add configuration Select: c/c++:(gdb) to start, the configuration information will be automatically generated (if you need to know the meaning of the red font, point the mouse to it, there will be a prompt message, vscode yyds)

• Modify the generated configuration information as follows:

{
    "configurations": [
    {
        "name": "gdbApp",
        "type": "cppdbg",
        "request": "launch",
        "program": "${workspaceFolder}/gdbApp",
        "args": [],
        "stopAtEntry": false,
        "cwd": "${workspaceFolder}",
        "environment": [],
        "externalConsole": false,
        "MIMode": "gdb",
        "miDebuggerPath":
        "/usr/local/arm/gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gdb",
        "miDebuggerServerAddress": "192.168.0.50:2001"
        "setupCommands": [
            {
                "description": "for gdb Enable neat printing",
                "text": "-enable-pretty-printing",
                "ignoreFailures": true
            },
            {
                "description":  "Set disassembly style to Intel",
                "text": "-gdb-set disassembly-flavor intel",
                "ignoreFailures": true
            }
        ]
    }
    ]
}

Run and debug

• Start the development board and execute the gdb service command (enter the debug host, which is the ubuntu ip address)

gdbserver 192.168.0.67:2001 gdbApp //Start gdbserver on the development board

• run -> start debugging

This can be used like keil iar ccs vs and other ide tools