Tech Report CS-91-28

An Operating System Development Environment

Robert Boyer

May 1991


An operating system development environment has been created that allows prototype operating systems to be built, debugged, and executed as user-mode applications running on a host workstation. Operating system code can be written entirely in a high-level language, and the host system's compilers, debuggers, profilers, and any other available development tools can be used throughout the development process. The environment presents a conceptual machine to the operating system developer consisting of a single processor with virtual memory support, a priority interrupt scheme, kernel and user-mode stacks, and simulated peripheral devices. Special instructions present in most machine architectures, such as traps and privileged processor instructions, are emulated by having the prototype operating system call special-purpose library procedures. Priority-driven device interrupts are simulated by altering the context of the running operating system to directly invoke interrupt handlers and to restore the interrupted context upon handler exit.

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