Full system simulator
A full-system simulator is a computer program that simulates computer systems at such a level of detail that complete software stacks from real systems can run on the simulator without any modification. A full system simulator effectively provides virtual hardware that is independent of the nature of the host computer. The full-system model typically has to include processor cores, peripheral devices, memories, interconnection buses, and network connections. Full system simulation can speed the software development process by making it easier to detect, recreate and repair flaws. [1]
The defining property of full-system simulation compared to an instruction set simulator is that the model allows real device drivers and operating systems to be run, not just single programs. Thus, full-system simulation makes it possible to simulate individual computers and networked computer nodes with all their software, from network device drivers to operating systems, network stacks, middleware, servers, and application programs.
The use of multi-core processors is driving the need for full system simulation, because it can be extremely difficult and time consuming to recreate and debug errors without the controlled environment provided by virtual hardware. [2]
Examples of full system simulation include:
- PDP-11 simulator in 1980s
- g88 in late 1980s for modeling a uniprocessor M881100-based system, capable of booting Unix
- gsim in early 1990s for modeling multiple processors with shared memory.
- Simics: starting from 1994, modeling systems using Alpha, AMD64, ARM, EM64T, IA-64, MIPS, PowerPC, SPARC-V8 and -V9, and x86 CPUs
- SimOS: for MIPS-based multiprocessors
- SimNow: AMD full-system simulator for x86 and x86_64 systems
- gpsim : Microchip PICmicro system simulator
- Open Virtual Platforms (OVP) [3], consisting of the freely available simulator OVPsim, a library of models of processors, peripherals and platforms, and APIs which enable users to develop their own models. The models in the library are open source, written in C, and include the MIPS 4K, 24K and 34K cores.