  The complexity of automotive systems is increasing quickly due to the
integration of novel functionalities such as assisted or autonomous driving.
However, increasing complexity poses considerable challenges to the automotive
supply chain since the continuous addition of new hardware and network cabling
is not considered tenable. The availability of modern heterogeneous
multi-processor chips represents a unique opportunity to reduce vehicle costs
by integrating multiple functionalities into fewer Electronic Control Units
(ECUs). In addition, the recent improvements in open-hardware technology allow
to further reduce costs by avoiding lock-in solutions.
  This paper presents a mixed-criticality multi-OS architecture for automotive
ECUs based on open hardware and open-source technologies. Safety-critical
functionalities are executed by an AUTOSAR OS running on a RISC-V processor,
while the Linux OS executes more advanced functionalities on a multi-core ARM
CPU. Besides presenting the implemented stack and the communication
infrastructure, this paper provides a quantitative gap analysis between an
HW/SW optimized version of the RISC-V processor and a COTS Arm Cortex-R in
terms of real-time features, confirming that RISC-V is a valuable candidate for
running AUTOSAR Classic stacks of next-generation automotive MCUs.
