Dalvik version of Hello World

This article is a small exercise in Dalvik instruction set to create a new text file renamed Helloworld.smali, and then write out the HelloWorld class program code as follows [Java]View PlainCopyprint?

2. .    class public Lhelloworld; #定义类名
4. .    Super Ljava/lang/object; #定义父类
6. . method Public static main ([ljava/lang/string;) V #声明静态main () methods
8. . registers 4 #程序中使用v0, V1, v2 register and a parameter register
10. . Parameter #一个参数
12. . Prologue #代码起始指令
14. #空指令
16. Nop
18. Nop
20. Nop
22. Nop
24. #数据定义指令 V0 = 8; v1 = 5; v2 = 3;
26. const/v0, 0x8
28. const/4 v1, 0x5
30. const/4 v2, 0x3
32. #数据操作指令 V1 = v2;
34. Move V1, v2
36. #数组操作指令 V0 = new int[v0]; v1 = v0
38. New-array V0, V0, [I
40. Array-length v1, V0
42. #实例操作指令 v1 = new StringBuilder ();
44. new-instance v1, Ljava/lang/stringbuilder;
46. #方法调用指令 V1.init ();
48. Invoke-direct {v1}, ljava/lang/stringbuilder;-><init> () V
50. #跳转指令if (v0! = 0)
52. If-nez V0,: Cond_0
54. goto:goto_0
56. : Cond_0
58. #数据运算指令 v2 = v2 << v2; (v2 = = )
60. shl-int v2, v2, v2
62. #数据转换指令 v2 = (float) v2;
64. int-to-Float v2, v2
66. #数据运算指令 v2 + = v2; (v2 = = 48.0)
68. add-Float v2, v2, v2
70. #比较指令 V0 = V2 < v2; (V0 = = 0)
72. cmpl-float V0, v2, v2
74. #字段操作指令 PrintStream v0 = System.out; V1 = "Hello World"
76. Sget-object V0, ljava/lang/system;->out:ljava/io/printstream;
78. const-string v1, "Hello World" #构造字符串
80. #方法调用指令 v0.println (v1); V0.println (v2);
82. invoke-virtual {v0, v1}, Ljava/io/printstream;->println (ljava/lang/string;) V
84. invoke-virtual {v0, v2}, Ljava/io/printstream;->println (F) V
86. #返回指令
88. : goto_0
90. return-void #返回空
92. . End method

Next compile the Smali file, you need to use the Smali.jar. In cmd Enter the following command (Smali.jar and Helloworld.smali in the same directory): Java-jar smali.jar-o classes.dex Helloworld.smali will be generated Classes.dex Compress. zip format to connect an Android device or emulator, enter the following command in cmd input adb push classes.zip/data/localadb shell Dalvikvm-cp/data/local/classes.zip HelloWorld effect

Dalvik version of Hello World (RPM)