A flexible technique for OS-support in instruction level simulators

Instruction level simulators are key tools for architecture development and evaluation. Being able to run real target applications on the simulator is important to create realistic workloads for measurements. The authors present a technique for adding runtime support which allows general applications, e.g., SPEC benchmarks and X-applications, to be executed on the simulator. The basic idea is to implement a scheme where system calls are executed by the host computer on behalf of the target program. An identity mapping from target addresses to virtual addresses in the simulator process is a key feature of this scheme. The main advantage of the technique is its simplicity. By applying the technique we were able to build a DEC Alpha simulator, which executes real life OSF/I applications on a SPARC host under SunOS, in three man-weeks