Micro Kernel on Virtual Machines

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The goal of this research is to develop an operating system on top of Java virtual machines so that it is independent from underlying hardware and CPU architecture. In particular, we have developed a micro kernel on top of Java virtual machines.In 1998, we have modified the Java virtual machine to be run as a stand-alone application and replaced BIOS by this modified Java virtual machine so that micro kernels can be developed independently from underlying CPU architecture.In 1999, we have designed a process model for the Java micro kernel and tried a simple file system for the purpose of verifying our micro kernel mechanisms.We have also implemented a TCP/IP protocol stack on our Java virtual machine and measured its performance. As for TCP/IP protocol stacks, BSD uses mbuf and X kernel uses graph structure, whereas we have developed a protocol stack which is suitable for Java. Java does not have pointers, so there is no way to point inside data structures. In addition, Java restricts casting between data types. Therefore, we have designed a buffer structure which is suitable for Java and used monitors for thread communication. Since the Java virtual machine is not a native machine, its performance may be a problem, but from our measurements its performance is much better than we have expected.