Using a Processor Emulator on a Microkernel-based Operating System

This paper presents an architecture that allows multiple isolated commodity operating systems to run concurrently on a microkernel-based operating system without restricting the CPU architecture of guest operating systems. There are several systems that can execute multiple guest operating systems by using a virtual machine monitor or a microkernel-based operating system. Almost all of them, however, require that the CPU architecture of a guest operating system and a host operating system are identical and the guest operating system needs to be modified. Our architecture does not require the both of them and the prototype system that we have developed achieved the execution of multiple guest operating systems such as Linux and FreeBSD compiled for several CPU architecture without the modification of them. Since it involved decreasing the performance of a guest operating system, we propose several techniques to improve the performance in this paper. Future embedded system will become more complex, so our approach offers a new way to reuse existing applications and operating systems.