VxWorks
APPLICATION PROGRAMMER'S GUIDE
®
6.6
VxWorks Application Programmer's Guide, 6.6
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VxWorks Application Programmer's Guide, 6.6
14 Nov 07
Part #: DOC-16076-ND-00
iii
Contents
1 Overview ............................................................................................... 1
1.1 Introduction ............................................................................................................. 1
1.2 Related Documentation Resources ..................................................................... 2
1.3 VxWorks Configuration and Build ..................................................................... 3
2 Applications and Processes ............................................................... 5
2.1 Introduction ............................................................................................................. 6
RTP Applications and VxWorks SMP ................................................... 8
Migrating Kernel Applications to RTP Applications .......................... 8
2.2 Configuring VxWorks For Real-time Processes .............................................. 9
2.3 Real-time Processes ................................................................................................ 11
2.3.1 Real-time Process Life-Cycle .................................................................. 13
2.3.2 Processes and Memory ............................................................................ 14
2.3.3 Processes and Tasks ................................................................................. 16
2.3.4 Processes, Inheritance, and Resource Reclamation ............................. 16
2.3.5 Processes and Environment Variables .................................................. 18
2.3.6 Processes and POSIX ............................................................................... 18
VxWorks
Application Programmer's Guide, 6.6
iv
2.4 POSIX PSE52 Support ........................................................................................... 19
2.5 Developing VxWorks Applications .................................................................... 19
2.5.1 C and C++ Libraries ................................................................................ 19
2.5.2 Application Structure .............................................................................. 20
2.5.3 VxWorks Header Files ............................................................................. 20
2.5.4 Applications, Processes, and Tasks ....................................................... 23
2.5.5 Applications and VxWorks Kernel Component Requirements ........ 24
2.5.6 Building Applications .............................................................................. 25
2.5.7 C++ Applications ..................................................................................... 25
2.5.8 Processes and Hook Routines ................................................................. 26
2.5.9 Application APIs, System Calls, and Library Routines ...................... 26
System Calls .............................................................................................. 26
VxWorks Libraries ................................................................................... 27
API Documentation ................................................................................. 27
2.5.10 POSIX ......................................................................................................... 27
2.6 Developing Application Libraries ...................................................................... 28
2.6.1 Library Initialization ................................................................................ 28
C++ Library Initialization ....................................................................... 29
Handling Initialization Failures ............................................................. 30
2.6.2 Library Termination ................................................................................. 30
Using atexit() for Termination Routines ............................................... 31
2.6.3 Developing Static Libraries ..................................................................... 31
2.6.4 Developing Shared Libraries .................................................................. 32
Configuring VxWorks for Shared Libraries ......................................... 36
Building Shared Libraries and Dynamic Applications ....................... 37
VxWorks Run-time C Library libc.so .................................................... 51
Using Plug-Ins .......................................................................................... 52
Using readelf to Examine Dynamic ELF Files ...................................... 55
Getting Runtime Information About Shared Libraries ....................... 55
Debugging Shared Libraries ................................................................... 59
Working With Shared Libraries From a Windows Host .................... 59
Contents
v
2.7 Creating and Managing Shared Data Regions ................................................. 61
2.7.1 Configuring VxWorks for Shared Data Regions ................................. 62
2.7.2 Creating Shared Data Regions ............................................................... 62
2.7.3 Accessing Shared Data Regions ............................................................. 63
2.7.4 Deleting Shared Data Regions ................................................................ 64
2.8 Executing Applications ......................................................................................... 64
2.8.1 Running Applications Interactively ...................................................... 65
Starting Applications ............................................................................... 65
Stopping Applications ............................................................................. 66
2.8.2 Running Applications Automatically ................................................... 67
Startup Facility Options .......................................................................... 68
Application Startup String Syntax ......................................................... 68
Specifying Applications with a Startup Configuration Parameter ... 70
Specifying Applications with a Boot Loader Parameter .................... 70
Specifying Applications with a VxWorks Shell Script ........................ 71
Specifying Applications with usrRtpAppInit( ) ................................. 72
2.8.3 Applications and Symbol Registration ................................................. 73
2.9 Bundling Applications with a VxWorks System using ROMFS .................. 74
2.9.1 Configuring VxWorks with ROMFS ..................................................... 75
2.9.2 Building a System With ROMFS and Applications ............................ 75
2.9.3 Accessing Files in ROMFS ...................................................................... 76
2.9.4 Using ROMFS to Start Applications Automatically ........................... 76
3 Multitasking .......................................................................................... 77
3.1 Introduction ............................................................................................................. 79
3.2 Tasks and Multitasking ....................................................................................... 80
3.2.1 Task States and Transitions .................................................................... 81
3.3 Task Scheduling ..................................................................................................... 85
3.3.1 Task Priorities ........................................................................................... 85
