Package spim-7.4-1

spim is a self-contained simulator that will run MIPS32 assembly language programs. It reads and executes assembly language programs written for this processor. spim also provides a simple debugger and minimal set of operating system services. spim does not execute binary (compiled) programs. spim implements almost the entire MIPS32 assembler-extended instruction set. (It omits most floating point comparisons and rounding modes and the memory system page tables.) The MIPS architecture has several variants that differ in various ways (e.g., the MIPS64 architecture supports 64-bit integers and addresses), which means that spim will not run programs compiled for all types of MIPS processors. MIPS compilers also generate a number of assembler directives that spim cannot process. These directives usually can be safely deleted. Earlier versions of spim (before 7.0) implemented the MIPS-I instruction set used on the MIPS R2000/R3000 computers. This architecture is obsolete (though, has never been surpassed for its simplicity and elegance). spim now supports the more modern MIPS32 architecture, which is the MIPS-I instruction set augmented with a large number of occasionally useful instructions. MIPS code from earlier versions of SPIM should run without changes, except code that handles exceptions and interrupts. This part of the architecture changed over time (and was poorly implemented in earlier versions of spim). Code of this sort need to be updated. Examples of the new code are in /sw/lib/spim/exceptions.s and /sw/share/spim/Tests/tt.io.s. spim implements both a simple, terminal-style interface and a window interface. The spim program provides a simple terminal interface and the xspim program provides the windowing interface.