Describing the Operating System for Accurate User-mode Simulation

这是一个迫切的项目，致力于对指定操作系统(OS)特征所需的关键元素进行高度探索性的调查，以允许创建与一套模拟工具完全交互的体系结构模型。该工具套件Coent(工具的共生)包括规范语言，允许研究人员表达新的指令集和微体系结构，以及用于自动生成相应的功能和时序协同模拟器、编译器、链接器、加载器、调试器、汇编器、反汇编程序和完全集成的仪器设备的基础设施，以在这个新的设计空间内实现有意义的实验。令人信服的？S从规范和其他相关元素自动生成功能模拟器的能力将于今年发布。这一功能急切地解决了一个问题，即在模拟复杂的体系结构时，能够指定操作系统支持是很重要的，不仅是作为一组外部调用，而且作为与体系结构的其余部分集成的特定模型。当前的体系结构依赖于操作系统的服务和策略，而操作系统本身需要随着未来十年预期的体系结构和应用程序的根本性变化而发展。通过该项目，该团队开发了一种方法，可以同时研究新的硬件和软件范例，具有极大的灵活性，并且不会产生迄今令人望而却步的成本，即通过定制的操作系统实施手动构建完整的硬件和软件模拟基础设施。传统的系统仿真方法要么忽略操作系统对性能的影响，要么求助于代价高昂且缺乏灵活性的全系统仿真，在全系统仿真中直接执行实际的操作系统实现。前者提供了不切实际的结果，而后者不承认转换范式所需的那种探索。本项目的目标是将相对较新的硬件体系结构功能和时序联合仿真方法扩展到“伪全系统仿真”，其中操作系统成为仿真建模和工具框架中的一流元素。模拟从规范派生的操作系统模型还将支持敏感性和重要性分析，这在当前基于模拟的研究中经常被忽视，尽管它们对于理解新方法的真正影响是必不可少的。

This is an EAGER project that addresses a highly exploratory investigation into key elements needed to specify the characteristics of an operating system (OS) in a way that permits an architectural model to be created that interacts fully with a suite of simulation tools.The suite of tools, CoGenT (CoGeneration of Tools), include specification languages to allow researchers to express novel instruction sets and micro-architectures and the infrastructure for automatic generation of corresponding functional and timing co-simulators, compilers, linkers, loaders, debuggers, assemblers, disassemblers, and a fully integrated instrumentation facility to enable meaningful experimentation within this new design space. CoGenT?s ability to automatically generate a functional simulator from a specification, and other related elements, will be released this year.This EAGER addresses the problem that, in simulating complex architectures, it is important to be able to specify OS support, not just as a set of external calls, but as a specific model that integrates with the rest of the architecture. Current architectures rely on the services and policies of the operating system, and the operating system itself needs to evolve with the radical shifts in architecture and applications that are anticipated in the next decade.With this project, this team develops an approach that enables simultaneous research into novel hardware and software paradigms, with great flexibility, and without the heretofore prohibitive cost of manually building a complete hardware and software simulation infrastructure with a tailored OS implementation. Traditional system simulation approaches either ignored OS impact on performance or resorted to costly and inflexible full system simulation where an actual OS implementation is executed directly. The former provides unrealistic results, and the latter does not admit the kind of exploration needed for transformative paradigm shifts.The goal of this project is to extend the relatively recent approach of functional and timing co-simulation for hardware architectures into "pseudo-full system simulation", where the OS becomes a first-class element in the simulation modeling and instrumentation framework. Simulating an OS model derived from a specification will also enable sensitivity and significance analyses, often neglected in current simulation-based research even though they are essential to understanding the real impact of new approaches.