Reconfigurable Embedded System Prototyping Platform And Operating System

As a new computing architecture, reconfigurable computing has become a subject of a great deal of research. Its key feature is the ability to perform computations in hardware to increase performance, while retaining much of the flexibility of a software solution. Reconfigurable computing is spreading widely in various domains from embedded system to high performance computing. However, developers working with reconfigurable computing still lack the support of operating systems and convenient application developing tools.This paper mainly focuses on the operating system support for reconfigurable computing, and building a suitable prototype platform is the base of further researching. The main works of this paper are shown as follow:Firstly, this paper classifies current modern reconfigurable computing platforms into several groups. The properties of reconfigurable computing platforms required by an operating system are given. Then the design of a reconfigurable embedded system prototype platform is present.Secondly, this paper presents and implements Embedded System Integrated Design Environment (ESIDE) based on Eclipse platform, for supporting the application development on the prototype platform. ESIDE supports embedded system design at several abstract levels and achieves a top-down design procedure. The design tools at each level and other external EDA tools are integrated into a whole environment. With the management of the IP Database, ESIDE provides well support for team cooperation.Thirdly, a heterogeneous IP integration algorithm is presented and is implemented in ESIDE. It adopts hierarchical integration and flexible connection IPs which enable it support very complex IP connection structures. IPs with different bus interfaces can be integrated freely via bus protocol converters. The practice of virtual design technique and automatic IP integration reduce the complexity of system design significantly.Fourthly, based on the essential differences between software-tasks and hardware-tasks, this paper presents an operating system framework for reconfigurable systems using uniform multi-task model. Then the inter-task communication architecture is presented, and a Linux based operating system for reconfigurable computing is presented. A Hardware Task Stub Thread is combined to each hardware task to deal with inter-task communications. This simplifies hardware task designing, and makes the operating system compatible with current software programming models and inter-task communication mechanisms. It supports dynamic partially reconfigurable FPGAs and dynamic task creation, so it can manage hardware resources more efficiently.Finally we focus on the placement and scheduling of hardware tasks on reconfigurable devices. Previous works are summarized, and the notion of recognition-earliest is introduced, that is the algorithm can arrange the start time of a newly arrived task as early as possible. A fast placement algorithm and two recognition-earliest on-line scheduling algorithms are proposed. The evaluation results show that our new scheduling algorithm achieves the best performance compared with previous algorithms, while has a quite low runtime cost, and the placement algorithm is one of the best algorithms among all previous works.