Embedded Computing SpiderWare® STREAMS Implementation of the UNIX STREAMS Environment

SpiderWare STREAMS is an implementation of the UNIX STREAMS environment which can run under a Real Time Operating System (RTOS) or stand alone on a Front End Board. SpiderWare STREAMS enables SpiderWare Frame Relay, ISDN, X.25, TCP and OSI STREAMS-based protocol stacks to run in many operating system environments.

SpiderWare STREAMS acts as an enabling technology which allows OEMs and Systems Integrators to provide standards-based solutions, across different platforms, to end users throughout the world.

Key Features

The STREAMS environment provides a well defined standard framework for communications protocol drivers and related services such as terminal support.

It supports:

• A buffer management system supporting zero copy manipulation of buffers
• A queuing and flow control mechanism
• Flexible and efficient interconnection of protocol

Portability

SpiderWare STREAMS provides a framework in which STREAMS based protocol stacks can run. It is compatible with the UNIX kernel STREAMS implementations, but can be ported to almost any software environment. SpiderWare STREAMS provides POSIX-compliant interfaces for applications.

SpiderWare STREAMS can be supported in various environments, for example:

On a Front-End Processor:

No Operating System is required on the front-end processor; SpiderWare STREAMS runs free standing if required. Communication with the host processor in bus based systems uses a cross-bus driver (SXB). For host systems supporting STREAMS, SXB extends the linkages between protocol modules transparently across the bus. For hosts not running STREAMS, an appropriate host-side driver is all that is needed. Versions of SXB for PC/AT and PCI systems are currently available.

In a Real-Time Kernel:

SpiderWare STREAMS and the protocol stacks run as a single task. Applications use an interface library which is easily modified for new environments. Versions of this layer have been written for several real time systems.

In an Operating System Kernel:

The core of SpiderWare STREAMS may be added to extensible kernels as a device driver, allowing STREAMS protocol stacks to be ported to most environments. Combinations of these environments are also possible, for example — SpiderWare STREAMS in kernel and also on a front-end processor, connected together by the cross-bus driver (SXB).

Developer Support

Support is provided for debugging STREAMS itself (to aid in porting) and for debugging STREAMS drivers and modules, as follows:

• Compilation options can be set for checking usage of message blocks, consistency checking and tracing
• Debugging routines are provided that can give information on the state of SpiderWare STREAMS
• Error reporting is also provided, for printing error messages of specified severity

Coexistence

SpiderWare STREAMS can coexist with any SpiderWare STREAMS-based protocol stacks, or any other STREAMS-based protocol stack. It enables these protocol stacks to run on many different environments. In conjunction with the cross-bus driver, SpiderWare STREAMS provides flexibility as to where the protocol stacks can run in any given architecture.

Operating Environment

SpiderWare products are designed to help quicken an OEMs time to market. All the code is written in C and has been ported to numerous CPUs and Operating Systems, either by our customers or ourselves.

Architectures include Intel 80X86 and i960, Motorola 68k and PowerPC, SPARC, MIPS and HP-PA. Software environments include VxWorks, pSOS, QNX, VRTX, RTEMS, SVR4, Unixware, NT, Solaris, DG-UX, HP/RT and HP/UX.