Go to JMI home page Press Announcement #209 FOR IMMEDIATE RELEASE
EMBEDDED SYSTEMS CONFERENCE, NAVY PIER, CHICAGO, IL, MARCH 31, 1998 - JMI Software Systems announced today a major new version of PSX, the POSIX extension to C EXECUTIVE, JMI's widely-used real-time operating system kernel. PSX is a substantial subset of POSIX 1003.1 for use in dedicated applications, where full multi-user, POSIX-conformant UNIX is inappropriate. PSX is based on the standard C EXECUTIVE kernel, and provides a bridge between C EXECUTIVE and full POSIX. The new PSX version, available for Beta delivery in May, adds support for POSIX threads, mutexes, and condition variables.
The POSIX standards promote the portability of application software across multiple workstation architectures using POSIX-conformant versions of UNIX and UNIX-like operating systems. Workstation operating systems include features such as multi-user and multi-group services, hardware memory management, and additional facilities for a complete program development environment. Complete POSIX, therefore, implies a significant performance overhead compared to a dedicated, execute-only kernel.
PSX combines the performance of a small real-time kernel with a substantial subset of the POSIX system calls. PSX provides preemptive multitasking as well as dynamic process and thread creation, but does not include the capability for multiple users nor multiple groups. With C EXECUTIVE, PSX, and POSIX-conformant UNIX, companies can standardize on a compatible set of operating systems for all embedded applications. Small systems can be migrated to larger hosts, and subsystems running on workstations can be selectively moved to small platforms, including hand-held devices.
PSX is comprised of the C EXECUTIVE kernel plus a subset of POSIX 1003.1 appropriate for deeply embedded systems. In addition to the standard C EXECUTIVE system calls, PSX now has 120 POSIX 1003.1 system calls for input/output, signals and other process primitives, process environment functions, file and directory operations, device control, and (now with Release 3.3) threads, mutexes, and condition variables. An additional 16 POSIX 1003.1 calls are partially implemented, or "stubbed." The large PSX system call library does not imply large embedded systems - only those system calls referenced by the application code are linked into the system image, providing a naturally scalable kernel.
PSX has been implemented completely in portable ANSI C, and uses the existing portable C EXECUTIVE kernel as a base. The new POSIX 1003.1 subset is therefore potentially available on all processors supported by C EXECUTIVE, from 8- and 16-bit microprocessors up through 32-bit CISC, RISC, and DSP architectures.
C EXECUTIVE, the base kernel for PSX, is a ROMable, multitasking operating system kernel for real-time embedded systems. Examples of current C EXECUTIVE and PSX-based products include helicopter avionics, wireless routers, machine tool control, laser printers, hand-held devices, engine test stands, GPS receivers, FAA and military radar systems, paging systems, cellular telephones, medical laboratory instruments, industrial and military PBX products, communication satellites, cardiac monitors, and portable military radios, among many other embedded applications.
PSX and C EXECUTIVE also offer an optional file system, CE-DOSFILE. CE-DOSFILE replicates the PC/DOS file structure on external media, allowing any microprocessor to read and write PC/DOS disks. The file system provides contiguous files for use in high-performance data acquisition applications. CE-VIEW provides a flexible system-level debugging tool for testing on the target system. CE-TCP and CE-SNMP are optional communications packages.
JMI supports PSX and C EXECUTIVE with distributors in Europe, Japan, India, Korea, and Taiwan. For more information on C EXECUTIVE and PSX, contact JMI Software Systems, Inc., 904 Sheble Lane, Spring House, PA 19477-0481, TEL (215) 628-0840, FAX (215) 628-0353. Email: inquiries@jmi.com, WWW URL: www.jmi.com
C EXECUTIVE is a registered trademark of JMI Software Systems, Inc. PSX, CE-DOSFILE, CE-VIEW, CE-TCP, and CE-SNMP are trademarks of JMI Software Systems, Inc.
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