AHA: Automatic Hardware Abstraction in Operating Systems

操作系统一直服务于抽象和补充底层硬件的能力的目的：从概念上讲，操作系统通过部分解释和硬件资源的复用来概括和扩展处理器的指令集;然而，即使在OS实现中也不直接使用硬件，而是通过进一步的，抽象和泛化的代价是低效率（关于存储要求、能量要求、可能性、可预测性、安全性等）。具体应用：广义概念的力量没有得到充分利用-但仍然提供。硬件资源通过多路复用进行虚拟化-即使在直接映射可能的情况下也是如此。我们使用AHA的目标（操作系统设计中的自动硬件抽象）是通过对操作系统所代表的应用程序-硬件桥进行非常深入但完全自动化的专门化来改善系统软件的非功能属性。我们希望研究OS功能的语义等效实现，这些实现（仅）对于该特定应用程序是语义等效的，但可以更直接地映射到硬件功能，可以从具体的应用程序及其与操作系统的交互中生成。在AHA的上下文中，“应用程序”和“操作系统功能”涵盖嵌入式专用系统（汽车控制单元，物联网设备，嵌入式服务器节点......）的领域;“硬件”代表商用现成平台（英飞凌AURIX、ARM等）使用它们的特定特性以及用于完全专用的处理器硬件在极端情况下，特定应用程序所需的特定操作系统功能直接实例化到处理器的命令集和流水线中。应用程序开发人员可以透明地在不同的专业化阶段中进行选择：从“经典”的基于软件的专业化，到标准硬件上的应用程序/硬件特定的专业化，再到硬件本身的专业化，以覆盖实际需要的操作系统扩展。我们想用AHA回答的基本研究问题是：系统软件的应用程序和硬件特定专业化/通用化的最高可能程度是什么？在专业化过程可以完全自动进行的前提下，通过针对具体问题的专业化，可以以什么样的成本实现哪些效率增益？

Operating systems have always served the purpose of abstraction and complementing the capabilities of the underlying hardware:Conceptually, the operating system generalizes and expands the instruction set of the processor by partial interpretation and multiplexing of hardware resources;it thereby simplifies the development and portability of applications.However, even in the OS implementation the hardware is also not used directly, but via a further, partially interpreting hardware abstraction layer.The price for abstraction and generalization are inefficiencies (with regard to storage requirements, energy requirements, eventuality, predictability, security, etc.) for the concrete application:The power of the generalized concepts is not fully used - but still provided.Hardware resources are virtualized by multiplexing - even in cases a direct mapping would be possible.Our goal with AHA (Automated Hardware Abstraction in Operating System Design) is to improve nonfunctional properties of system software by a very deep, but fully automated specialization of the application-hardware bridge represented by the operating system.We want to investigate, how semantically equivalent implementations of the OS functionality, which are semantically equivalent (only) for this specific application, but can be mapped more directly to hardware features, can be generated from a concrete application and their interactions with the operating system.In the context of AHA, "Application" and "operating system functionality" covers the domain of embedded special purpose systems (automotive control unit, IoT device, embedded server node ...);"Hardware" stands for commercial-of-the-shelf platforms (Infineon AURIX, ARM, ...) using their specific characteristics as well as for completely application-specific processor hardware (such as RISC-V).In an extreme case, the specific operating-system functionality required by a particular application is instantiated directly into the command set and pipeline of the processors.The application developer can -- transparently -- select among different specialization stages: from "classic" software-based specialization over application-/hardware-specific specialization on standard hardware up to the specialization of the hardware itself to cover the actually needed operating-system extensions.The basic research question we want to answer with AHA is: What is the highest possible degree of application- and hardware-specific specialization / generalization of system software? Which efficiency gains can be achieved at what cost by problem-specific specialization, on the premise that the process of specialization can be performed completely automatically?