Embedded FreeBSD cookbook

250 Pages·2003·1.16 MB·English

Embedded
FreeBSD Cookbook

A Volume in the
Embedded Technology™ Series
Embedded
FreeBSD Cookbook
by Paul Cevoli
An imprint of Elsevier Science
Amsterdam Boston London New York Oxford Paris
San Diego San Francisco Singapore Sydney Tokyo
iv
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Printed in the United States of America
Preface .................................................................................. vii

Prerequisites and Other Resources .................................................... vii

1 Getting Started .................................................................. 1

Overview ............................................................................................. 1

Embedded Systems ............................................................................ 1

Internet Appliances ............................................................................. 2

Compatibility of upgrades ........................................................................ 3

Time to market ......................................................................................... 4

Labor pool ................................................................................................ 4

Licensing.................................................................................................. 4

The DIO Server Appliance .................................................................. 4

FreeBSD .................................................................................................. 5

GNU Development Tools ......................................................................... 6

Java ......................................................................................................... 7

Server ...................................................................................................... 7

Data Acquisition ....................................................................................... 7

Boot Device.............................................................................................. 7

Summary............................................................................................. 8

2 Systems Programming ..................................................... 9

Overview ............................................................................................. 9

Process ............................................................................................... 9

The ........................................................................................................... 10

System Call.............................................................................................. 10

The ........................................................................................................... 11

System Call.............................................................................................. 11

The ........................................................................................................... 12

System Call.............................................................................................. 12

The ........................................................................................................... 12

System Call.............................................................................................. 12

An Example.............................................................................................. 12

Process IDs.............................................................................................. 13

Security .................................................................................................... 14

An Example.............................................................................................. 15

The ........................................................................................................... 16

and ........................................................................................................... 16

System Calls ............................................................................................ 16

File Descriptors ........................................................................................ 17

Permissions ............................................................................................. 17

Current Working Directory ....................................................................... 17

The ........................................................................................................... 18

and ........................................................................................................... 18

System Calls ............................................................................................ 18

The ........................................................................................................... 18

System Call.............................................................................................. 18

Priority...................................................................................................... 19

State......................................................................................................... 20

The ........................................................................................................... 20

Function ................................................................................................... 20

The ........................................................................................................... 21

System Call.............................................................................................. 21

Daemons............................................................................................. 21

Fork.......................................................................................................... 21
Create a new session .............................................................................. 22

Close file descriptors................................................................................ 22

Change the current working directory ...................................................... 22

Set the file mode creation mask............................................................... 22

Handle Child Exit Status .......................................................................... 22

The ........................................................................................................... 22

Function ................................................................................................... 22

The ........................................................................................................... 23

Function ................................................................................................... 23

Summary............................................................................................. 25

3 System Calls...................................................................... 27

Overview ............................................................................................. 27

Library Functions and System Calls.................................................... 27

Software Interrupt .................................................................................... 29

Passing Data............................................................................................ 29

An Example.............................................................................................. 30

Creating a System Call ....................................................................... 32

Load Handler ........................................................................................... 32

System Call Arguments ........................................................................... 34

The ........................................................................................................... 34

System Call.............................................................................................. 34

The ........................................................................................................... 36

Structure .................................................................................................. 36

The System Call Number ......................................................................... 36

The SYSCALL_MODULE Macro ............................................................. 38

Command Definitions............................................................................... 39

Command Table ...................................................................................... 40

The ........................................................................................................... 40

Function ................................................................................................... 40

Command Function Handlers .................................................................. 42

The ........................................................................................................... 45

Program ................................................................................................... 45

An example .............................................................................................. 47

Summary............................................................................................. 48

4 Device Driver ..................................................................... 49

Overview ............................................................................................. 49

Driver Environment ............................................................................. 49

Driver Structure ................................................................................... 51

The ........................................................................................................... 52

Structure .................................................................................................. 52

The ........................................................................................................... 53

Structure .................................................................................................. 53

The ........................................................................................................... 55

Structure .................................................................................................. 55

The ........................................................................................................... 57

Structure .................................................................................................. 57

The ........................................................................................................... 57

Structure .................................................................................................. 57

The ........................................................................................................... 57

Macro ....................................................................................................... 57

The ........................................................................................................... 58

Structure .................................................................................................. 58

The DIO24 Device Driver.................................................................... 59
The ........................................................................................................... 61

Function ................................................................................................... 61

The ........................................................................................................... 62

Function ................................................................................................... 62

The ........................................................................................................... 63

Function ................................................................................................... 63

The ........................................................................................................... 64

Function ................................................................................................... 64

The ........................................................................................................... 66

Function ................................................................................................... 66

The ........................................................................................................... 66

Function ................................................................................................... 66

The ........................................................................................................... 67

Function ................................................................................................... 67

The ........................................................................................................... 68

Function ................................................................................................... 68

The ........................................................................................................... 69

Function ................................................................................................... 69

The ........................................................................................................... 69

Function ................................................................................................... 69

Register Shadowing ................................................................................. 71

The ........................................................................................................... 73

Function ................................................................................................... 73

Summary............................................................................................. 76

5 Midlevel Interface Library................................................. 77

Overview ............................................................................................. 77

Shared Libraries .................................................................................. 77

Accessing the Device Driver ............................................................... 79

The ........................................................................................................... 80

System Call.............................................................................................. 80

The ........................................................................................................... 81

System Call.............................................................................................. 81

The ........................................................................................................... 81

System Call.............................................................................................. 81

The ........................................................................................................... 82

System Call.............................................................................................. 82

The ........................................................................................................... 82

System Call.............................................................................................. 82

PCI-DIO24 Hardware Registers.......................................................... 82

The DIO24 Application Interface Library............................................. 87

The ........................................................................................................... 89

and ........................................................................................................... 90

Functions ................................................................................................. 90

The ........................................................................................................... 92

and ........................................................................................................... 92

Functions ................................................................................................. 92

The ........................................................................................................... 94

and ........................................................................................................... 94

Functions ................................................................................................. 94

The diopolarity ......................................................................................... 95

The ........................................................................................................... 95

and ........................................................................................................... 95

functions................................................................................................... 95

The ........................................................................................................... 97

and ........................................................................................................... 97
Functions ................................................................................................. 97

The ........................................................................................................... 98

Function ................................................................................................... 98

Summary............................................................................................. 101

6 Daemons............................................................................ 103

Overview ............................................................................................. 103

Introduction to TCP/IP ......................................................................... 103

IP Addressing........................................................................................... 105

ARP.......................................................................................................... 105

RARP ....................................................................................................... 106

ICMP ........................................................................................................ 106

Ports......................................................................................................... 106

UDP ......................................................................................................... 106

TCP.......................................................................................................... 107

Socket System Calls ........................................................................... 107

Connection Initiation ................................................................................ 109

The ........................................................................................................... 111

System Call.............................................................................................. 111

The ........................................................................................................... 112

System Call.............................................................................................. 112

The ........................................................................................................... 112

System Call.............................................................................................. 112

The ........................................................................................................... 113

System Call.............................................................................................. 113

The ........................................................................................................... 113

System Call.............................................................................................. 113

The ........................................................................................................... 114

System Call.............................................................................................. 114

The ........................................................................................................... 115

System Call.............................................................................................. 115

The DIO Daemon ................................................................................ 115

The ........................................................................................................... 115

Structure .................................................................................................. 116

The ........................................................................................................... 117

Function ................................................................................................... 117

The ........................................................................................................... 119

Function ................................................................................................... 119

The ........................................................................................................... 120

Function ................................................................................................... 120

Summary............................................................................................. 122

7 Remote Management ........................................................ 123

Overview ............................................................................................. 123

Using Secure Shell (SSH)................................................................... 123

The DIOShell....................................................................................... 130

The ........................................................................................................... 132

Function ................................................................................................... 132

The ........................................................................................................... 133

Function ................................................................................................... 133

The ........................................................................................................... 134

Function ................................................................................................... 134

The ........................................................................................................... 135

Function ................................................................................................... 135

The ........................................................................................................... 136
Function ................................................................................................... 136

The ........................................................................................................... 137

Function ................................................................................................... 137

The ........................................................................................................... 138

Function ................................................................................................... 138

The ........................................................................................................... 139

Function ................................................................................................... 139

The ........................................................................................................... 139

Function ................................................................................................... 139

The ........................................................................................................... 140

Function ................................................................................................... 140

The ........................................................................................................... 141

Utility ........................................................................................................ 141

Summary............................................................................................. 142

8 JNI Layer............................................................................ 143

Overview ............................................................................................. 143

The JDK .............................................................................................. 143

Creating the JNI Layer ........................................................................ 145

The DIOLineState Class .......................................................................... 147

The DIOLineNumber Class...................................................................... 148

The DIOLineDirection Class .................................................................... 149

The DIOIfJNI Class .................................................................................. 150

The ........................................................................................................... 154

Function ................................................................................................... 154

The ........................................................................................................... 154

Function ................................................................................................... 154

The ........................................................................................................... 155

Function ................................................................................................... 155

The Makefile ............................................................................................ 155

Summary............................................................................................. 156

9 Web Access Using Tomcat .............................................. 157

Overview ............................................................................................. 157

Tomcat ................................................................................................ 157

bin ............................................................................................................ 158

JSP Overview...................................................................................... 160

Comments................................................................................................ 161

Directives ................................................................................................. 161

Declarations ............................................................................................. 162

Expressions ............................................................................................. 162

Code Scriptlets......................................................................................... 162

The DIO JSP Page.............................................................................. 162

Summary............................................................................................. 165

10 Building the Kernel ......................................................... 167

Overview ............................................................................................. 167

The ........................................................................................................... 168

Keyword ................................................................................................... 168

The ........................................................................................................... 168

Keyword ................................................................................................... 168

The ........................................................................................................... 168

Keyword ................................................................................................... 168

The ........................................................................................................... 168