Linux Real-time Research On Zynq And Its Application In FC

In avionics ground simulation systems,FC networks are commonly used for high-speed data transmission between devices.The FC-AE-ASM node card in the system is currently implemented using the "x86+FPGA" software and hardware design architecture.This architecture uses a discrete design model of "hardware first,software second",which requires repeated iterations,is time-consuming and costly,and often unpredictable errors occur during joint debugging.This paper presented a FC-AE-ASM node card design scheme based on Xilinx Zynqfully programmable platform.The Zynq platform integrated a dual-core ARM Cortex-A9 processor and FPGA in a single chip,which were connected through the AXI on-chip bus.Compared with the "x86+FPGA" architecture,it significantly improved hardware utilization,reduced power consumption,and made the design between software and hardware more synergistic and flexible.In addition,For the higher requirements for the real-time operating system of avionics ground simulation system,while Linux has been generally used as time-sharing operating system,whose real-time performance has not been paid enough attention.Therefore,another focus of this article was to build a real-time Linux system based on Zynq-7000 SoC to meet the design requirements.The main work of this paper is as follows:1.According to the research background and engineering requirements,analyze the main factors that limit the real-time performance of the Linux system,and use the Preempt-RT patch method to transform the Linux kernel in real time.2.Design the data exchange channel:Compare several different data transmission methods,use the AXI_HP interface and PL side DMA to realize the transmission of software and hardware data.3.Design the node card driver under the Linux framework.Cooperate with the hardware to complete the reception and transmission of FC frames,and provide a mechanism to control the hardware at the application layer.4.Design the node card application program.The main functions include establishing communication with the master control machine,analyzing and executing the commands of the master control machine.5.Test and compare the task response delay between the modified real-time Linux and standard Linux.The result showing that the maximum response delay of real-time Linux is only 69?s,which verified the effectiveness of the real-time transformation.At the same time,built a test platform to test the performance and function of the FC-AE-ASM node card,the result of which verified it's data transmission function while the transmission rate meets the engineering requirements.