VxWorks
DEVICE DRIVER DEVELOPER’S GUIDE
®
6.4
VxWorks Device Driver Developer's Guide
Copyright © 2006 Wind River Systems, Inc.
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VxWorks Device Driver Developer’s Guide, 6.4
26 Sep 06
Part #: DOC-15882-ND-00
iii
Contents
1 Introduction .......................................................................................... 1
1.1 About This Document ........................................................................................... 1
1.2 Additional Documentation .................................................................................. 2
1.3 Terminology ............................................................................................................. 3
2 Design Overview .................................................................................. 5
2.1 Introduction ............................................................................................................. 5
2.2 Design Goals ........................................................................................................... 5
2.2.1 Performance .............................................................................................. 6
2.2.2 Code Flexibility and Portability ............................................................. 6
2.2.3 Maintenance and Readability ................................................................. 7
2.2.4 Ease of Configuration .............................................................................. 7
2.2.5 Performance Testing ................................................................................ 7
2.2.6 Code Size ................................................................................................... 8
2.2.7 Reentrancy and Number of Devices ...................................................... 8
2.3 Common Design Concerns ................................................................................... 8
VxWorks
Device Driver Developer’s Guide, 6.4
iv
2.3.1 Varied Hardware Designs ....................................................................... 9
2.3.2 Memory-Mapped Chips .......................................................................... 9
2.3.3 I/O-Mapped Chips .................................................................................. 9
2.3.4 Multi-Function Chips .............................................................................. 10
2.3.5 Bus Support ............................................................................................... 10
VxBus-Compliant Drivers ....................................................................... 11
Legacy Drivers .......................................................................................... 11
VxBus Bus Controller Device Drivers ................................................... 12
2.3.6 Interrupt Controllers ................................................................................ 12
2.4 Design Guidelines ................................................................................................. 12
2.4.1 Names and Locations .............................................................................. 13
2.4.2 Documentation and Standards ............................................................... 13
2.4.3 Per-Device Data Structure ....................................................................... 15
2.4.4 Per-Driver Data Structure ....................................................................... 15
2.4.5 Driver Interrupt Service Routines .......................................................... 15
2.4.6 Access Macros ........................................................................................... 16
2.4.7 Multi-Function Devices and VxBus ....................................................... 18
3 Adding Drivers to VxWorks ................................................................. 19
3.1 Adding an Existing Driver to Your BSP ............................................................. 19
3.1.1 BSP Support for Legacy (Non-VxBus) Device Drivers ....................... 20
3.1.2 Project Facility ........................................................................................... 20
3.1.3 Component Descriptor Files ................................................................... 21
3.2 Porting Drivers ........................................................................................................ 21
3.2.1 Porting a Driver From An Earlier Version of VxWorks ...................... 21
3.2.2 Porting a Legacy Driver to the VxBus Model ...................................... 21
3.2.3 Porting From Another OS ....................................................................... 22
3.3 Creating a New Driver Using the Legacy Model ............................................. 23
Contents
v
3.3.1 Step-By-Step Instructions ........................................................................ 23
Top-Down Design .................................................................................... 23
Bottom-Up Implementation ................................................................... 25
Helpful Hints ............................................................................................ 26
3.3.2 Cache Considerations .............................................................................. 26
Using the Cache Library .......................................................................... 27
Developing a cacheLib Strategy ............................................................. 31
3.3.3 Hotswap Support ..................................................................................... 35
3.3.4 Downloadable Driver Support ............................................................... 35
4 END Ethernet Drivers ........................................................................... 37
4.1 Introduction ............................................................................................................. 37
4.2 END Driver Overview ........................................................................................... 38
4.2.1 Driver Environment ................................................................................. 38
The MUX ................................................................................................... 38
Network Interface Drivers and Protocols ............................................. 39
The MUX, Protocol, and Driver API ..................................................... 40
Driver Components ................................................................................. 42
Protocols That Use the MUX API .......................................................... 43
Interactions With the MUX API ............................................................. 47
Network Layer to Data Link Layer Address Resolution .................... 53
4.2.2 VxWorks OS Interface .............................................................................. 54
Understanding How VxWorks Launches and Uses Your Driver ...... 54
Executing Calls Waiting In the Network Job Queue ........................... 58
Adding Your Network Interface Driver to VxWorks .......................... 59
Allocating, Initializing, and Utilizing Memory Resources ................. 61
Handling Packet Reception .................................................................... 69
Handling Packet Transmission ............................................................... 82
Implementing Checksum Offloading .................................................... 88
Implementing Required Entry Points and Structures ......................... 95
4.3 The END Driver Development Process ............................................................. 118
