diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json
index 979a682..0c10c49 100644
--- a/.vscode/c_cpp_properties.json
+++ b/.vscode/c_cpp_properties.json
@@ -6,7 +6,7 @@
                 "${workspaceFolder}/**",
                 // "${workspaceFolder}/labcodes_answer/**/", 
                 // 由于按顺序搜索，所以如果这样的话搜索到lab1_result中的同名头文件就不会引用到lab2_result中的同名头文件导致错误
-                "${workspaceFolder}/labcodes_answer/lab3_result/**/"
+                "${workspaceFolder}/labcodes_answer/lab4_result/**/"
             ],
             "defines": [],
             "compilerPath": "/usr/bin/gcc",
diff --git a/.vscode/launch.json b/.vscode/launch.json
index 4382c07..68bbaac 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -11,7 +11,7 @@
             "program": "bin/kernel",
             "args": [],
             "stopAtEntry": false,
-            "cwd": "${workspaceFolder}/labcodes_answer/lab3_result",
+            "cwd": "${workspaceFolder}/labcodes_answer/lab4_result",
             "environment": [],
             "externalConsole": false,
             "MIMode": "gdb",
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..79cacfe
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+    "debug.allowBreakpointsEverywhere": true
+}
\ No newline at end of file
diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index c12ab8c..baae814 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -9,7 +9,7 @@
                 "env": {
                     "DISPLAY": ":0",
                 },
-                "cwd": "${workspaceFolder}/labcodes_answer/lab3_result"
+                "cwd": "${workspaceFolder}/labcodes_answer/lab4_result"
             },
             
             "problemMatcher": [
diff --git a/labcodes_answer/lab4_result/Makefile b/labcodes_answer/lab4_result/Makefile
index e6648f1..bad9339 100644
--- a/labcodes_answer/lab4_result/Makefile
+++ b/labcodes_answer/lab4_result/Makefile
@@ -214,7 +214,7 @@ endif
 # files for grade script
 
 TARGETS: $(TARGETS)
-
+all: $(TARGETS)
 .DEFAULT_GOAL := TARGETS
 
 QEMUOPTS = -hda $(UCOREIMG) -drive file=$(SWAPIMG),media=disk,cache=writeback
@@ -229,6 +229,8 @@ qemu-nox: $(UCOREIMG) $(SWAPIMG)
 	$(V)$(QEMU) -serial mon:stdio $(QEMUOPTS) -nographic
 
 TERMINAL := gnome-terminal
+gdb: $(UCOREIMG) $(SWAPIMG)
+	$(V)$(QEMU) -S -s -parallel stdio $(QEMUOPTS) -serial null
 
 debug: $(UCOREIMG) $(SWAPIMG)
 	$(V)$(QEMU) -S -s -parallel stdio $(QEMUOPTS) -serial null &