diff --git a/related_info/lab1/Makefile b/related_info/lab1/Makefile
index e6f9adb..4bcf613 100644
--- a/related_info/lab1/Makefile
+++ b/related_info/lab1/Makefile
@@ -1,4 +1,4 @@
-all: lab1-ex0.exe lab1-ex1.exe
+all: lab1-ex0.exe lab1-ex1.exe lab1-ex3.s
 
 lab1-ex0.exe: defines.h lab1-ex0.s
 	gcc  -m32 -g  -o lab1-ex0.exe lab1-ex0.s
@@ -10,6 +10,10 @@ lab1-ex1.exe: lab1-ex1.c
 	strace -c ./lab1-ex1.exe
 	echo "watch the interrupts in linux"
 	more /proc/interrupts
+
+lab1-ex3.s: lab1-ex3.c
+	echo "show .s files"
+	gcc -m32 -S lab1-ex3.c
 	
 clean:
-	rm  lab1-ex0.exe lab1-ex1.exe
+	rm  lab1-ex0.exe lab1-ex1.exe lab1-ex3.s
diff --git a/related_info/lab1/lab1-ex3.c b/related_info/lab1/lab1-ex3.c
new file mode 100644
index 0000000..b81d908
--- /dev/null
+++ b/related_info/lab1/lab1-ex3.c
@@ -0,0 +1,17 @@
+void inline ex1(void){
+        asm ("movl $0xffff, %%eax\n");
+}
+
+void inline ex2(void){
+        unsigned cr0;
+        asm volatile ("movl %%cr0, %0\n" :"=r"(cr0));
+        cr0 |= 0x80000000;
+        asm volatile ("movl %0, %%cr0\n" ::"r"(cr0));
+}
+
+void inline ex3(void){
+long __res, arg1 = 2, arg2 = 22, arg3 = 222, arg4 = 233;
+__asm__ __volatile__("int $0x80"
+   : "=a" (__res)
+   : "0" (11),"b" (arg1),"c" (arg2),"d" (arg3),"S" (arg4));
+ }
diff --git a/related_info/lab1/lab1-ex3.md b/related_info/lab1/lab1-ex3.md
new file mode 100644
index 0000000..95437fb
--- /dev/null
+++ b/related_info/lab1/lab1-ex3.md
@@ -0,0 +1,8 @@
+# inline assembly for C example
+Try below command
+```
+gcc -m32 -S lab1-ex3.c
+```
+Then you will get lab1_ex3.s
+
+Try to understand the contents of this .s file and the relation between .c file and .s file.