VSCode integration

Debug Linux kernel within Visual Studio Code

Create configuration files

The following steps have to be performed in your Linux source directory.

Create tasks.json

Create a file called tasks.json in the directory .vscode and paste the following contents into it:

You may want to change line 28 and 36, as they point to the directory where your qemu files are located.

{
// See https://go.microsoft.com/fwlink/?LinkId=733558
// for the documentation about the tasks.json format
"version": "2.0.0",
"tasks": [
{
"label": "Build Kernel for ARM",
"type": "shell",
"command": "make",
"args": [
"ARCH=arm",
"CROSS_COMPILE=arm-linux-gnueabihf-",
"-j6"
],
"group": {
"kind": "build",
"isDefault": true
},
"problemMatcher": [
"$gcc"
]
},
{
"label": "Copy zImage",
"command": "cp",
"args": [
"arch/arm/boot/zImage",
"../emulation/boot/efi/boot/bootarm.efi"
],
"dependsOn":["Build Kernel for ARM"]
},
{
"label": "Run qemu",
"command": "/usr/bin/qemu-system-arm -m 1024 -cpu cortex-a15 -M virt -pflash flash0.img -pflash flash1.img -nographic -drive file=fat:rw:boot/ -smp '4' -s",
"options": {
"cwd": "${workspaceFolder}/../emulation"
},
"type": "shell",
"isBackground": true,
"problemMatcher": [
{
"pattern": [
{
"regexp": ".",
"file": 1,
"location": 2,
"message": 3
}
],
"background": {
"activeOnStart": true,
"beginsPattern": ".",
"endsPattern": ".",
}
}
],
"dependsOn":["Copy zImage"]
},
{
"label": "Terminate All Tasks",
"command": "echo ${input:terminate}",
"type": "shell",
"problemMatcher": []
}
],
"inputs": [
{
"id": "terminate",
"type": "command",
"command": "workbench.action.tasks.terminate",
"args": "terminateAll"
}
]
}

Create launch.json

Create a file called launch.json in the directory .vscode and paste the following contents into it:

{
// Use IntelliSense to learn about possible attributes.
// Hover to view descriptions of existing attributes.
// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
"version": "0.2.0",
"configurations": [
{
"name": "(gdb) Run",
"type": "cppdbg",
"request": "launch",
"program": "${workspaceRoot}/vmlinux",
"miDebuggerServerAddress": "localhost:1234",
"miDebuggerPath": "/usr/bin/gdb-multiarch",
"args": [],
"stopAtEntry": true,
"cwd": "${workspaceFolder}",
"environment": [],
"externalConsole": false,
"MIMode": "gdb",
"targetArchitecture": "arm",
"preLaunchTask": "Run qemu",
"postDebugTask": "Terminate All Tasks",
"setupCommands": [
{
"description": "Enable pretty-printing for gdb",
"text": "-enable-pretty-printing",
"ignoreFailures": true
}
]
}
]
}

Create c_cpp_properties.json

Create a file called c_cpp_properties.json in the directory .vscode and paste the following contents into it:

{
"configurations": [
{
"name": "Linux",
"includePath": [
"${workspaceFolder}",
"${workspaceFolder}/include",
"${workspaceFolder}/include/uapi",
"${workspaceFolder}/include/generated",
"${workspaceFolder}/arch/arm/include",
"${workspaceFolder}/arch/arm/include/uapi",
"${workspaceFolder}/arch/arm/include/generated"
],
"defines": [
"__KERNEL__"
],
"compilerPath": "/usr/bin/arm-linux-gnueabihf-gcc",
"cStandard": "gnu17",
"cppStandard": "c++17",
"intelliSenseMode": "linux-gcc-arm",
"browse": {
"path": [
"${workspaceFolder}",
"${workspaceFolder}/include",
"${workspaceFolder}/mm",
"${workspaceFolder}/fs",
"${workspaceFolder}/kernel"
],
"limitSymbolsToIncludedHeaders": true,
"databaseFilename": ""
}
}
],
"version": 4
}

Debug

Press F5 to start debugging. The following steps will be performed:

  • Compile Kernel

  • Copy zImage to qemu EFI partition

  • Launch qemu

  • Start GDB debugging

The following keys are important:

  • F9 for creating a breakpoint

  • F10 for going a step forward

  • F11 for stepping into a function

  • F12 to step out of a function