09-11-2012, 05:37 PM
RTOS VxWorks
53RTOS-VxWorks.pdf (Size: 46.98 KB / Downloads: 40)
Abstract
The VxWorks is the high performance real time operating system. Most widely used RTOS is the
VxWorks. The operating system, which performs the proceeding in the real time instead of latter time
with storing it in some memory. Development environment for this OS is Tornado, Wind River Systems
Inc, US. This is scalable Operating system in which kernel, I/O system, network layer and all are in
component nature and which are being used whenever required to add to Kernel. Modularity of this
feature is one of the main advantage in development of real time applications.
Introduction
VxWorks is the real time operating system (RTOS) unlike other operating systems
like windows, Linux etc. It is the multi tasking and single user operating system.
RTOS is response even for external events. The main advantage of RTOS is less
context switching time, accuracy and predictable response. Development environment
for vxWorks is Tornado.
VxWorks: A Partner in the Real-time Development Cycle
UNIX and Windows hosts are excellent systems for program development and for
many interactive applications. However, they are not appropriate for real-time
applications. On the other hand, traditional real-time operating systems provide poor
environments for application development or for non-real-time components of an
application, such as graphical user interfaces (GUIs).
Rather than trying to create a single operating system that "does it all," the Wind
River philosophy is to utilize two complementary and cooperating
operating systems
(VxWorks and UNIX, or VxWorks and Windows) and let each do what it does best.
VxWorks handles the critical real-time chores, while the host machine is used for
program development and for applications that are not time-critical.
You can scale VxWorks to include exactly the feature combinations your application
requires. During development, you can include additional features to speed your work
(such as the networking facilities), then exclude them to save resources in the final
version of your application.
You can use the cross-development host machine to edit, compile, link, and store
real-time code, but then run and debug that real-time code on VxWorks. The resulting
VxWorks application can run standalone--either in ROM or disk-based--with no
further need for the network or the host system.
However, the host machine and VxWorks can also work together in a hybrid
application, with the host machine using VxWorks systems as real-time "servers" in a
networked environment. For instance, a VxWorks system controlling a robot might
itself be controlled by a host machine that runs an expert system, or several VxWorks
systems running factory equipment might be connected to host machines that track
inventory or generate reports.
High-Performance Real-time Kernel Facilities
The VxWorks kernel, wind, includes multitasking with preemptive priority
scheduling, intertask synchronization and communications facilities, interrupt
handling support, watchdog timers, and memory management.
POSIX Compatibility
VxWorks provides most interfaces specified by the 1003.1b standard (formerly the
1003.4 standard), simplifying your ports from other conforming systems.
I/O System
VxWorks provides a fast and flexible ANSI C-compatible I/O system, including
UNIX standard buffered I/O and POSIX standard asynchronous I/O. VxWorks
includes the following drivers:
Network driver -for network devices (Ethernet, shared memory)
Pipe driver -for intertask communication
RAM "disk" driver-for memory-resident files
SCSI driver -for SCSI hard disks, diskettes, and tape drives
Keyboard driver -for PC x86 keyboards (x86 BSP only)
Display driver -for PC x86 VGA displays (x86 BSP only)
Disk driver -for IDE and floppy disk drives (x86 BSP only)
Parallel port driver -for PC-style target hardware
Local File Systems
VxWorks provides fast file systems tailored to real-time applications. One file system
is compatible with the MS-DOS® file system, another with the RT-11 file system, a
third is a "raw disk" file system, a fourth supports SCSI tape devices, and a fifth
supports CD-ROM devices.
C++ Development Support
In addition to general C++ support including the iostream library and the standard
template library, the optional component Wind Foundation Classes adds the
following C++ object libraries: