A Linux-based support for developing real-time applications on heterogeneous platforms with dynamic FPGA reconfiguration

Computing platforms for next-generation cyber–physical systems are evolving towards heterogeneous architectures comprising different processing elements and hardware accelerators. In particular, SoC-FPGA platforms, including multiple general-purpose processing cores tightly coupled with an FPGA fabric, represent an attractive solution due to their flexibility, efficiency, and timing predictability. On these platforms, dedicated hardware accelerators implemented on the FPGA fabric can offload computationally intensive activities from general-purpose processing cores. Furthermore, dynamic partial reconfiguration allows virtualizing the FPGA resources by sharing them among multiple hardware accelerators over time. Although very promising, FPGA-based hardware acceleration also introduces new challenges, such as managing and scheduling multiple concurrent acceleration and reconfiguration requests. The FRED framework has been proposed to address these challenges while preserving the predictability required by real-time systems. FRED is based on a device model that matches the capabilities of contemporary SoC-FPGA platforms and comes with an ad-hoc scheduling infrastructure designed to guarantee bounded response times for DPR-enabled accelerated tasks. This paper presents Fred-Linux, the reference implementation of the FRED framework for GNU/Linux. Fred-Linux allows developing rich applications while leveraging predictable FPGA-based hardware acceleration for performing heavy computations. Fred-Linux has been developed using the Zynq-7000 and Zynq-UltraScale＋ by Xilinx as reference platforms, and it can be easily ported and extended on other platforms thanks to its modular design.