University of Plymouth PEARL https://pearl.plymouth.ac.uk 04 University of Plymouth Research Theses 01 Research Theses Main Collection 2015 Improved Composability of Software Components through Parallel Hardware Platforms for In-Car Multimedia Systems Knirsch, Andreas http://hdl.handle.net/10026.1/3511 Plymouth University All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. Copyright Statement This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without the author’s prior consent. Improved Composability of Software Components through Parallel Hardware Platforms for In-Car Multimedia Systems by Andreas Knirsch A thesis submitted to Plymouth University in partial fulfilment for the degree of DOCTOR OF PHILOSOPHY January 2015 Abstract Improved Composability of Software Components through Parallel Hard- ware Platforms for In-Car Multimedia Systems Andreas Knirsch Recent years have witnessed a significant change to vehicular user interfaces (UI). This is the result of increased functionality, triggered by the continuous proliferation of vehicular software and computer systems. The UI represents the integration point that must fulfil particular requirements for usability despite the increased functionality. A concurrent present trend is the substitution of federated systems with integrated architectures. The steadily rising number of interacting functional components and the increasing integration density implies a growing complexity that has an effect on system development. This evolution raises demands for concepts that aid the composition of such complex and interactive embedded software systems, operated within safety critical environments. This thesis explores the requirements related to composability of software components, based on the example of In-Car Multimedia (ICM). This thesis proposes a novel software architecture that provides an integration path for next-generation ICM. The investigation begins with an examination of characteristics, existing frameworks and applied practice regarding the development and composition of ICM systems. To this end, constructive aspects are identified as potential means for improving composability of independently developed software components that differ in criticality, temporal and computational char- acteristics. This research examines the feasibility of partitioning software components by exploitation of parallel hardware architectures. Experimental evaluations demonstrate the applicabil- ity of encapsulated scheduling domains. These are achieved through the utilisation of multiple technologies that complement each other and provide different levels of con- tainment, while featuring efficient communication to preserve adequate interoperability. In spite of allocating dedicated computational resources to software components, certain resources are still shared and require concurrent access. Particular attention has been paid to management of concurrent access to shared resources to consider the software components’ individual criticality and derived priority. A software based resource arbiter is specified and evaluated to improve the system’s determinism. Within the context of automotive interactive systems, the UI is of vital importance, as it must conceal inher- ent complexity to minimise driver distraction. Therefore, the architecture is enhanced with a UI compositing infrastructure to facilitate implementation of a homogenous and comprehensive look and feel despite the segregation of functionality. The core elements of the novel architecture are validated both individually and in combi- nation through a proof-of-concept prototype. The proposed integral architecture supports the development and in particular the integration of mixed-critical and interactive sys- tems. Contents List of Figures xi List of Tables xiv List of Listings xv 1 Introduction and overview 1 1.1 Focus of this research . 4 1.2 Aims and objectives . 5 1.3 Method overview . 6 1.4 Thesis outline . 7 2 Review of software development for ICM 9 2.1 Terminology and introduction to ICM . 9 2.2 Characteristics of ICM systems . 12 2.2.1 Classification . 12 2.2.2 Environment . 14 2.2.3 Architecture . 14 2.2.4 Development . 16 2.2.5 Criticality . 18 2.2.6 User interface . 25 2.2.7 Connectivity . 26 2.2.8 Hardware . 29 2.3 Requirements . 30 2.3.1 Composability . 33 2.3.2 Functional suitability . 36 2.3.3 Usability . 37 2.3.4 Performance efficiency . 37 2.3.5 Reliability . 38 vii CONTENTS 2.3.6 Portability . 39 2.3.7 Maintainability . 42 2.3.8 Security . 43 2.4 Software frameworks . 43 2.4.1 AUTOSAR . 45 2.4.2 GENIVI . 47 2.4.3 Android . 48 2.4.4 OpenICM . 49 2.5 Summary . 51 3 Applied software composition for ICM 53 3.1 Development approach of automotive systems . 54 3.2 Exemplary real-world projects . 57 3.2.1 Project Alpha . 58 3.2.2 Project Beta . 58 3.2.3 Other projects . 59 3.3 Interpretation of the reviewed projects . 59 3.3.1 Management . 59 3.3.2 Domain knowledge . 61 3.3.3 Component interfaces . 61 3.3.4 Integration . 62 3.4 Summary . 64 4 Structuring software components 67 4.1 Inter-component communication . 68 4.2 Component partitioning . 69 4.2.1 Scheduling . 71 4.2.2 Partition scheduling . 77 4.2.3 Multicore architectures . 78 4.2.4 Interrupt affinities . 83 4.3 Related concepts . 85 4.3.1 Service orientation . 85 4.3.2 Budgeting . 86 4.3.3 Virtualisation . 87 4.3.4 Application containers . 90 4.3.5 Asymmetric Multi-Processing . 92 4.4 Applied structuring . 92 4.5 Summary . 98 5 Arbitrate resource utilisation 101 5.1 Parallel computing versus shared resources . 102 5.2 Requirements for a resource access arbiter . 104 5.3 Strategies for accessing shared resources . 106 viii CONTENTS 5.4 SHARB: a prototype architecture and implementation . 109 5.4.1 Architecture constraints and design decisions . 109 5.4.2 Architecture and functional principle . 110 5.4.3 Impact . 114 5.5 Applicability of SHARB . 115 5.5.1 Test setup . 116 5.5.2 Prioritization . 116 5.5.3 Temporal overhead . 119 5.6 Related research and alternatives for resource arbitration . 122 5.7 Summary . 124 6 Compositing User Interfaces 125 6.1 Requirements for an in-car user interface . 126 6.1.1 Architectural drivers for compositing . 127 6.1.2 Architectural drivers for communication . 128 6.2 Related architectures and research . 129 6.3 An architecture and prototype for compositing segregated UIs . 131 6.3.1 Conceptual components . 131 6.3.2 Prototype architecture . 133 6.4 Applicability of the ICM-Compositor . 136 6.5 Audio compositing . 139 6.6 Summary . 140 7 Interoperation of approaches and evaluation 141 7.1 An architecture to construct next-generation ICM . 141 7.1.1 Compatibility by containment . 142 7.1.2 Managed access to shared resources . 143 7.1.3 Compositing UI . 144 7.1.4 Interoperability by efficient communication . 144 7.2 Evaluation . 145 7.2.1 Implementation details of the demonstrator . 146 7.2.2 Discussion . 149 7.3 Summary . 151 8 Conclusions and future work 153 8.1 Achievements of the research . 153 8.2 Limitations . 154 8.3 Suggestions and scope for future work . 156 8.4 The future of In-Car Multimedia . 158 Bibliography 161 Glossary 187 ix CONTENTS Abbreviations 191 Index 195 Appendix A Experimental Results 201 A.1 Incompatible scheduling policies . 201 A.1.1 Listings . 203 A.2 Scheduling within virtualised environments . 203 A.2.1 Listings . ..