diff --git a/related_info/lab0/lab0_ex3.c b/related_info/lab0/lab0_ex3.c
index 4d2ce7e..d6e6c28 100644
--- a/related_info/lab0/lab0_ex3.c
+++ b/related_info/lab0/lab0_ex3.c
@@ -114,3 +114,47 @@ int main()
     return 0;
 }
 #endif
+
+//ex2
+#if 0
+#include "stdlib.h"
+
+struct gatedesc {
+    unsigned gd_off_15_0 : 16;        // low 16 bits of offset in segment
+    unsigned gd_ss : 16;            // segment selector
+    unsigned gd_args : 5;            // # args, 0 for interrupt/trap gates
+    unsigned gd_rsv1 : 3;            // reserved(should be zero I guess)
+    unsigned gd_type : 4;            // type(STS_{TG,IG32,TG32})
+    unsigned gd_s : 1;                // must be 0 (system)
+    unsigned gd_dpl : 2;            // descriptor(meaning new) privilege level
+    unsigned gd_p : 1;                // Present
+    unsigned gd_off_31_16 : 16;        // high bits of offset in segment
+};
+
+typedef struct gatedesc gatedesc;
+typedef unsigned int uint32_t;
+
+#define STS_IG32    0xE     // 32-bit Interrupt Gate
+#define STS_TG32    0xF     // 32-bit Trap Gate
+
+#define SETGATE(gate, istrap, sel, off, dpl) {            \
+    ((gatedesc*)(&gate))->gd_off_15_0 = (uint32_t)(off) & 0xffff;        \
+    ((gatedesc*)(&gate))->gd_ss = (sel);                                \
+    ((gatedesc*)(&gate))->gd_args = 0;                                    \
+    ((gatedesc*)(&gate))->gd_rsv1 = 0;                                    \
+    ((gatedesc*)(&gate))->gd_type = (istrap) ? STS_TG32 : STS_IG32;    \
+    ((gatedesc*)(&gate))->gd_s = 0;                                    \
+    ((gatedesc*)(&gate))->gd_dpl = (dpl);                                \
+    ((gatedesc*)(&gate))->gd_p = 1;                                    \
+    ((gatedesc*)(&gate))->gd_off_31_16 = (uint32_t)(off) >> 16;        \
+}
+
+int main()
+{
+	unsigned intr;
+	intr=8;
+	SETGATE(intr, 0,1,2,3);
+	printf("%d", intr);
+	return 0;
+}
+#endif
diff --git a/related_info/lab0/lab0_ex4.c b/related_info/lab0/lab0_ex4.c
index 6909260..93e2b31 100644
--- a/related_info/lab0/lab0_ex4.c
+++ b/related_info/lab0/lab0_ex4.c
@@ -168,3 +168,119 @@ int main()
     return 0;
 }
 #endif
+
+
+//ex5
+#if 0
+// compile with -nostdinc and explicitly provide header file directories
+#include "list.h"
+#include <stdio.h>
+
+struct MyDataType {
+    list_entry_t list;
+    int32_t data;
+};
+
+struct MyDataType x, y, z;
+
+void display() {
+    printf("x = %lx prev = %lx next = %lx \n", &x.list, x.list.prev, x.list.next); 
+    printf("y = %lx prev = %lx next = %lx \n", &y.list, y.list.prev, y.list.next); 
+    printf("z = %lx prev = %lx next = %lx \n", &z.list, z.list.prev, z.list.next);
+    printf("----------------------------------\n");
+}
+
+int main() {
+    // initialize
+    list_init(&x.list);
+    list_init(&y.list);
+    list_init(&z.list);
+
+    display(); 
+
+    // insert element
+    list_add(&x.list, &y.list);
+
+    display();
+
+    list_add_before(&x.list, &z.list);
+
+    display();
+
+    // delete element
+    list_del_init(&x.list);
+
+    display();
+
+    return 0;
+}
+#endif
+
+//ex6
+#if 0
+#include <stdio.h>
+#include <list.h>
+
+int main() {
+    struct list_entry first, second, third;
+    list_init(&first);
+    list_init(&second);
+    list_init(&third);
+    printf("Is empty:%d\n", list_empty(&first));
+    list_add_after(&first, &second);
+    printf("Is empty:%d\n", list_empty(&first));
+    list_add_before(&first, &third);
+    struct list_entry *temp = &first;
+    int num = 0;
+    while ((temp = list_prev(temp)) != &first)
+        num++;
+    printf("Total elem:%d\n", num);
+    list_del_init(&second);
+    list_del_init(&first);
+    printf("Is empty:%d\n", list_empty(&third));
+    return 0;
+}
+#endif
+
+//ex7
+#if 0
+#include <stdio.h>
+#include <list.h>
+
+struct Ints {
+  int data;
+  list_entry_t le;
+};
+
+#define le2struct(ptr) to_struct((ptr), struct Ints, le)
+#define to_struct(ptr, type, member) \
+  ((type *)((char *)(ptr) - offsetof(type, member)))
+#define offsetof(type, member) \
+  ((size_t)(&((type *)0)->member))
+
+int main() {
+  struct Ints one, two, three, *now_int;
+  list_entry_t *now;
+  one.data = 1;
+  two.data = 2;
+  three.data = 3;
+  list_init(&one.le);
+  list_add_before(&one.le, &two.le);
+  list_add_after(&one.le, &three.le);
+
+  now = &two.le;
+  while (1) {
+    now_int = le2struct(now);
+    printf("Current: %d\n", now_int->data);
+    now = now->next;
+    if (now == &two.le)
+      break;
+  }
+
+  return 0;
+}
+//输出
+//Current: 2
+//Current: 1
+//Current: 3
+#endif