add vscode config in `<root>/os/`

os/.vscode/launch.json

+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "(gdb) Qemu",
+            "type": "cppdbg",
+            "request": "launch",
+            "program": "${workspaceFolder}/target/riscv64gc-unknown-none-elf/debug/os",
+            "args": [],
+            "stopAtEntry": false,
+            "cwd": "${fileDirname}",
+            "environment": [],
+            "externalConsole": false,
+            "MIMode": "gdb",
+            "preLaunchTask": "Qemu",
+            "miDebuggerPath": "/usr/bin/riscv64-elf-gdb",
+            "miDebuggerServerAddress": "localhost:1234",
+            "setupCommands": [
+                {
+                    "description": "Enable pretty-printing for gdb",
+                    "text": "-enable-pretty-printing",
+                    "ignoreFailures": true
+                }
+            ]
+        }
+    ]
+}
\ No newline at end of file

os/.vscode/settings.json

+{
+    "rust-analyzer.cargo.target": "riscv64gc-unknown-none-elf",
+    "rust-analyzer.check.allTargets": false,
+    "rust-analyzer.check.extraArgs": [
+        "--target",
+        "riscv64gc-unknown-none-elf"
+    ]
+}

os/.vscode/tasks.json

+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "Qemu",
+            "type": "shell",
+            "command": "make debug LOG=TRACE",
+            "group": {
+                "kind": "none",
+                "isDefault": true
+            },
+            "isBackground": true,
+            "presentation": {
+                "echo": true,
+                "reveal": "always",
+                "focus": false,
+                "panel": "shared",
+                "showReuseMessage": false,
+                "clear": true
+            },
+            "problemMatcher": [
+                {
+                    "owner": "rust",
+                    "fileLocation": ["relative", "${workspaceFolder}"],
+                    "background": {
+                        "activeOnStart": true,
+                        "beginsPattern": ".",
+                        "endsPattern": ".",
+                    },
+                    "pattern": [
+                        {
+                            "regexp": ".",
+                            "file": 1,
+                            "line": 2,
+                            "column": 3,
+                            "severity": 4,
+                            "message": 5
+                        },
+                    ]
+                }
+            ]
+        }
+    ]
+}
\ No newline at end of file