RISC-V特权架构配置的硬件实现影响研究

Research on the Impact of the Hardware Implementation of RISC-V Privileged Architecture Configurations

RISC-V指令集的模块化设计,能够适用于从低功耗设备到高性能处理器等多个领域.RISC-V特权架构涵盖了系统中除非特权指令集以外的所有内容,包括特权指令以及运行操作系统和连接外部设备所需的附加功能.基于特权架构,分为32位和64位两类,涵盖特权等级、异常处理、物理内存保护、基于页面的虚拟内存和性能计数器等模块的32种配置,探索特权架构配置在不同应用场景下对功能和硬件资源开销的影响.在实现方式上,采用参数化配置来选择系统的特权架构.实验结果表明,根据配置的特权架构不同,在采用相同非特权体系结构的情况下,最多会有28.63%的面积和40.83%的功耗差异.

The modular design of the RISC-V instruction set architecture enables its usage in many fields,from low-power devices to high-performance processors.RISC-V privileged architecture covers all aspects of systems beyond the unprivileged ISA,including privileged instructions as well as additional functionality required for running operating systems and attaching external devices.Based on the privileged architecture is divided into 32 bits and 64 bits categories,covering 32 configurations of privilege level,trap handler,physical memory protection,page-based virtual memory,and performance counters,exploring the impact of privilege architecture configurations on function and hardware overhead in various application situations.Parameterized configuration is used to select the privileged architecture of the system.The experimental results show that,depending on the different privileged architecture configurations,there will be at most 28.63%area and 40.83%power consumption differences under the same unprivileged architecture.