698 research outputs found

    An operating system for future aerospace vehicle computer systems

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    The requirements for future aerospace vehicle computer operating systems are examined in this paper. The computer architecture is assumed to be distributed with a local area network connecting the nodes. Each node is assumed to provide a specific functionality. The network provides for communication so that the overall tasks of the vehicle are accomplished. The O/S structure is based upon the concept of objects. The mechanisms for integrating node unique objects with node common objects in order to implement both the autonomy and the cooperation between nodes is developed. The requirements for time critical performance and reliability and recovery are discussed. Time critical performance impacts all parts of the distributed operating system; e.g., its structure, the functional design of its objects, the language structure, etc. Throughout the paper the tradeoffs - concurrency, language structure, object recovery, binding, file structure, communication protocol, programmer freedom, etc. - are considered to arrive at a feasible, maximum performance design. Reliability of the network system is considered. A parallel multipath bus structure is proposed for the control of delivery time for time critical messages. The architecture also supports immediate recovery for the time critical message system after a communication failure

    A Multiprocessor Distributed Debugger

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    This thesis presents the design and implementation of a distributed debugger. The debugger was designed to support the debugging of a system containing multiple processors from a single debug console. The debugger implementation consists of host software which runs on a VAX minicomputer and target software which runs on Intel SDK-86 single board computers. The host and targets communicate using an RS-232 channel. The debugger supports breakpoints, disassembly of target code, symbolic reference of program procedures and variables, and download of Intel Object Module Format binary files

    CRAY mini manual. Revision D

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    This document briefly describes the use of the CRAY supercomputers that are an integral part of the Supercomputing Network Subsystem of the Central Scientific Computing Complex at LaRC. Features of the CRAY supercomputers are covered, including: FORTRAN, C, PASCAL, architectures of the CRAY-2 and CRAY Y-MP, the CRAY UNICOS environment, batch job submittal, debugging, performance analysis, parallel processing, utilities unique to CRAY, and documentation. The document is intended for all CRAY users as a ready reference to frequently asked questions and to more detailed information contained in the vendor manuals. It is appropriate for both the novice and the experienced user

    Minimalistic SDHC-SPI hardware reader module for boot loader applications

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    This paper introduces a low-footprint full hardware boot loading solution for FPGA-based Programmable Systems on Chip. The proposed module allows loading the system code and data from a standard SD card without having to re-program the whole embedded system. The hardware boot loader is processor independent and removes the need of a software boot loader and the related memory resources. The hardware overhead introduced is manageable, even in low-range FPGA chips, and negligible in mid- and high-range devices. The implementation of the SD card reader module is explained in detail and an example of a multi-boot loader is offered as well. The multi-boot loader is implemented and tested with the Xilinx's Picoblaze microcontroller

    Verification of primitive Sub-Ghz RF replay attack techniques based on visual signal analysis

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    As the low-cost options for radio traffic capture, analysis and transmission are becoming available, some security researchers have developed open-source tools that potentially make it easier to assess the security of the devices that rely on radio communications without the need for extensive knowledge and understanding of the associated concepts. Recent research in this area suggests that primitive visual analysis techniques may be applied to decode selected radio signals successfully. This study builds upon the previous research in the area of sub-GHz radio communications and aims to outline the associated methodology as well as verify some of the reported techniques for carrying out radio frequency replay attacks using low-cost materials and freely available software

    Development of a Reconfigurable Multi-Faceted Communications Device Using Partial Dynamic Reconfiguration

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    Supporting a variety of communication protocols has typically required extensive hard- ware and Input/Output (I/O) interfaces targeting each protocol specifically. Recent designs in the past ten years have created more dynamic approaches by using Field Programmable Gate Arrays (FPGAs) and embedded hardware to implement or simulate previous hardware I/O designs. With the constant increase in FPGA and embedded technologies the capabilities of dynamic implementations have expanded. This report addresses the design of an up-to-date reconfigurable multi-faceted embedded device targeting recent technological advances in FPGAs

    Usability improvements for the Friend-to-Friend Computing Pidgin Plugin

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    Olemasoleva Pidgini laienduse analüüs ja edasiarendus. Lisatud mitmed uued kasutajaliidese elemendid ja hõlbustatud ligipääs rakenduse funktsionaalsusele.Analysis of pre-existing Friend-to-Friend Computing Pidgin plugin and improving it. Several new user interface related features developed and better access to existing functionality
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