99 research outputs found

    Payload/orbiter contamination control requirement study: Computer interface

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    A preliminary assessment of the computer interface requirements of the Spacelab configuration contamination computer model was conducted to determine the compatibility of the program, as presently formatted, with the computer facilities at MSFC. The necessary Spacelab model modifications are pointed out. The MSFC computer facilities and their future plans are described, and characteristics of the various computers as to availability and suitability for processing the contamination program are discussed. A listing of the CDC 6000 series and UNIVAC 1108 characteristics is presented so that programming requirements can be compared directly and differences noted

    Methods to improve debug flow for intellectual property protection

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    Abstract. Every company wants to protect their intellectual property and limit customer visibility of confidential information. A company may protect its proprietary information by different ways. This thesis will compare different methods that try to protect intellectual property while maintaining the software debugging capability. Working with binary libraries without debug information makes customer support very difficult. When a company is developing a new product, time to market is important. Usually, the last months are very busy resolving urgent customer issues. Especially during this period, the slow process of debugging customer issues without debug information can cause delays and increase time to market. The goal of this thesis is to compare methods that protects intellectual property by making reverse engineering more difficult. Study of the upcoming GNU Compiler Collection (GCC) features related to debug data formats, such as DWARF5, is also carried out while working with the thesis. The approaches tried were split DWARF, injecting ELF files, stripping debug data, and code obfuscation. Also optimisation and their effect on disassembly was studied. The best solution was to compile the software with debug symbols and strip them to a separate file. This way the symbol data can be loaded separately into GDB. The symbol data layout and addresses are also always correct with the solution.Virheiden etsinnän työnkulun parantaminen immateriaaliomaisuudet huomioiden. Tiivistelmä. Yritykset haluavat suojella immateriaaliomaisuuksiaan ja rajoittaa asiakkaiden näkyvyyttä tietylle tasolle asti. Tämä lopputyö vertailee eri metodeja jotka koittavat suojata immateriaaliomaisuuksia, ilman että ohjelmiston virheidenkorjattavuus kärsii. Binäärikirjastot ilman virheenkorjaustietoja vaikeuttavat asiakkaan tukemista. Uutta tuotetta kehitettäessä, markkinoille tuloaika on yritykselle tärkeää. Yleensä viimeiset kuukaudet ovat kiireisiä asiakkaan ongelmien tutkimuksien kanssa ja kyseiset ongelmat tulisi olla ratkaistuna mahdollisimman nopeasti. Tämän lopputyön tavoitteena on vertailla mahdollisia metodeja, jotka suojaavat immateriaaliomaisuutta takaisinmallinnusta vastaan. Tarkoituksena on myös tutkia tulevia GNU kääntäjä-kokoelman (GCC:n) ominaisuuksia liittyen virheenkorjaustietoformaatteihin, kuten DWARF5. Ongelman ratkaisuun koitettiin pilkottuja virheenkorjaustietoja, ELFtiedoston injektointia, virheenkorjaustiedon riisumista ohjelmistosta ja koodin obfuskointia. Myös optimoinnin vaikutusta konekielestä takaisinmallinnettuun Assembly-muotoon tutkittiin. Paras ratkaisu oli kääntää ohjelmisto virheenkorjaustiedolla ja riisua ne omaan erilliseen tiedostoon. Näin ohjelmiston symbolitieto pystytään latamaan erikseen virheenjäljittemänä käytettyyn GNU Debuggeriin (GDB:hen). Näin symbolitietojen rakenne ja osoitteet ovat myös aina paikkansapitävät

    ANOPP programmer's reference manual for the executive System

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    Documentation for the Aircraft Noise Prediction Program as of release level 01/00/00 is presented in a manual designed for programmers having a need for understanding the internal design and logical concepts of the executive system software. Emphasis is placed on providing sufficient information to modify the system for enhancements or error correction. The ANOPP executive system includes software related to operating system interface, executive control, and data base management for the Aircraft Noise Prediction Program. It is written in Fortran IV for use on CDC Cyber series of computers

    A New Approach to Memory Partitioning in On-board Spacecraft Software. In Fabrice Kordon and Tullio Vardanega (eds.), Reliable Software Technologies

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    The current trend to use partitioned architectures in on-board spacecraft software requires applications running on the same computer platform to be isolated from each other both in the temporal and memory domains. Memory isolation techniques currently used in Integrated Modular Avionics for Aeronautics usually require a Memory Management Unit (MMU), which is not commonly available in the kind of processors currently used in the Space domain. Two alternative approaches are discussed in the paper, based on some features of Ada and state-of-the art compilation tool-chains. Both approaches provide safe memory partitioning with less overhead than current IMA techniques. Some footprint and performance metrics taken on a prototype implementation of the most flexible approach are included

    An Ada-like language to facilitate reliable coding of low cost embedded systems

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    Due to a lack of operating system (0/S) support, it is more difficult to develop programs for embedded systems than for workstations. For those developing on a low budget, the problem is often further compounded by the necessity of using inappropriate, 0/S dependent, compilers. This study attempts to ascertain those elements of a High Level Language (HLL) which are absolutely necessary and implementable to produce reliable, efficient, embedded programs without the benefit of a large budget. The study is based upon the Ada philosophy as the Ada language incorporates many desirable features for modelling real-world problems in terms of embedded solutions. By implication, the research provides a small step towards an increased availability of low cost tools to assist in the development of reliable and efficient code for use in medium performance embedded systems

    Optimization guide for programs compiled under IBM FORTRAN H (OPT=2)

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    Guidelines are given to provide the programmer with various techniques for optimizing programs when the FORTRAN IV H compiler is used with OPT=2. Subroutines and programs are described in the appendices along with a timing summary of all the examples given in the manual

    The engineering design integration (EDIN) system

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    A digital computer program complex for the evaluation of aerospace vehicle preliminary designs is described. The system consists of a Univac 1100 series computer and peripherals using the Exec 8 operating system, a set of demand access terminals of the alphanumeric and graphics types, and a library of independent computer programs. Modification of the partial run streams, data base maintenance and construction, and control of program sequencing are provided by a data manipulation program called the DLG processor. The executive control of library program execution is performed by the Univac Exec 8 operating system through a user established run stream. A combination of demand and batch operations is employed in the evaluation of preliminary designs. Applications accomplished with the EDIN system are described

    Linking Scheme code to data-parallel CUDA-C code

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    In Compute Unified Device Architecture (CUDA), programmers must manage memory operations, synchronization, and utility functions of Central Processing Unit programs that control and issue data-parallel general purpose programs running on a Graphics Processing Unit (GPU). NVIDIA Corporation developed the CUDA framework to enable and develop data-parallel programs for GPUs to accelerate scientific and engineering applications by providing a language extension of C called CUDA-C. A foreign-function interface comprised of Scheme and CUDA-C constructs extends the Gambit Scheme compiler and enables linking of Scheme and data-parallel CUDA-C code to support high-performance parallel computation with reasonably low overhead in runtime. We provide six test cases — implemented both in Scheme and CUDA-C — in order to evaluate performance of our implementation in Gambit and to show 0–35% overhead in the usual case. Our work enables Scheme programmers to develop expressive programs that control and issue data-parallel programs running on GPUs, while also reducing hands-on memory management

    Standardized development of computer software. Part 2: Standards

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    This monograph contains standards for software development and engineering. The book sets forth rules for design, specification, coding, testing, documentation, and quality assurance audits of software; it also contains detailed outlines for the documentation to be produced

    Documentation of the GLAS fourth order general circulation model. Volume 1: Model documentation

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    The volume 1, of a 3 volume technical memoranda which contains a documentation of the GLAS Fourth Order General Circulation Model is presented. Volume 1 contains the documentation, description of the stratospheric/tropospheric extension, user's guide, climatological boundary data, and some climate simulation studies
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