Virtual Open Systems Scientific Publications

Introduction

In the new era of industry 4.0, the importance of solutions to allow the co-execution of activities with different levels of criticality in common hardware platforms has become crucial. It is now a sought-after that in recent embedded systems there is the need to have at the same time features typical of generic operating systems (for connectivity, user interface, etc.) together with the ones of a real time operating systems (for interaction with critical sensors, rotors, motors, etc.). The most common solution to run multiple operating systems in a single platform is the use of virtualization. However, standard hypervisor solutions are designed and implemented focusing on the performance of the guests. This makes difficult to address the safety and security requirements of mixed criticality systems.

In this context, the RISC-V architecture is quickly gaining relevance in the industry and is bringing a new set of challenges and solutions regarding both safety and security. The use of standard virtualization solutions to implement mixed criticality solution is not possible today. In fact, instruction set extensions to support hypervisors have not yet reached the standard specification, and today there is no hardware platform in the market than can use them.

This paper proposes VOSySmonitoRV, a mixed-criticality solution for RISC-V platforms that does not need instruction set extensions to support hypervisors. VOSySmonitoRV is able to run multiple operating systems in a single platform partitioning the system resources and protecting the execution of real time/safety critical operating systems. Performance measurements related to interrupts and context switch operations, considered as key points for multi-operating systems performance, are presented to demonstrate the feasibility of such a design on RISC-V platform.