Time-predictable resource sharing for commercial-off-the-shelf embedded architectures

嵌入式系统正在从逻辑应用程序和子系统在不同硬件组件上实现的联合体系结构向使用广泛共享CPU时间、内存和电源等物理资源的日益集成的平台转变。此外，它们越来越多地使用商用现成(COTS)组件来制造，以试图提高性能并降低成本和上市时间。然而，将COTS集成到医疗、航空电子和汽车行业等安全关键系统中是具有挑战性的。这些系统需要严格的定时保证和子系统之间的隔离，以安全地与环境交互，但COT在设计时通常没有考虑到这些目标。 这项研究的主要目标是证明可以用高性能、廉价的COTS组件来构建安全的嵌入式系统。特别是，在这个项目中，我将开发一种方法学，以极大地提高基于COTS的嵌入式硬件体系结构中存储和通信子系统的时间可预测性。为此，我将使用编译器技术和操作系统抽象来控制多核任务的执行和通信，并为访问共享内存资源创建可预测的并发调度策略。 除非在安全关键的嵌入式行业引入新的设计方法，否则子系统集成以及安全验证和认证的成本将迅速失控。通过使系统执行可预测和可重复，我的方法将有助于开发更安全、性能更高、生产成本更低的新一代嵌入式系统。

Embedded systems are moving from federated architectures, where logical applications and subsystems are implemented on different hardware components, to progressively more integrated platforms which use extensive sharing of physical resources such as CPU time, memories, and power. Furthermore, they are increasingly built using Commercial-Off-The-Shelf (COTS) components in an attempt to increase performance and reduce cost and time to market. However, integrating COTS in safety-critical systems such as those in the medical, avionics and automotive industry is challenging. These systems require strict timing guarantees and isolation between subsystems to safely interact with the environment, but COTS are not typically designed with such objectives in mind. The main goal of this research is to prove that safe embedded systems can be built from high performance, inexpensive COTS components. In particular, in this project I will develop a methodology to greatly increase the time predictability of the memory and communication subsystems in COTS-based embedded hardware architectures. I will do so by controlling multicore task execution and communication using both compiler techniques and operating system abstractions, and by creating predictable and concurrent scheduling policies for access to shared memory resources. The cost of subsystem integration and safety verification and certification will quickly spiral out of control unless new design methodologies are introduced in the safety-critical embedded industry. By making system execution predictable and repeatable, my methodology will contribute to a new generation of embedded systems that are safer, more performant and cheaper to produce.