.\" $Header: /Software/SPIM/src/xspim.man 5     12/24/00 1:37p Larus $.TH spim 1.SH NAMExspim \- A MIPS R2000/R3000 Simulator.SH SYNTAX.B xspim[\|\fI-asm/-bare\fP	\fI-trap/-notrap\fP	\fI-quiet/-noquiet\fP	\fI-mapped_io/-nomapped_io\fP.br\fI-delayed_branches\fP	\fI-delayed_loads\fP.br\fI-stext size\fP	\fI-sdata size\fP	\fI-sstack size\fP	\fI-sktext size\fP	\fI-skdata size\fP	\fI-ldata size\fP	\fI-lstack size\fP	\fI-lkdata size\fP.br	\fI-hexgpr/-nohexgpr\fP	\fI-hexfpr/-nohexfpr\fP\|].br\fI-file file\fP \fI-execute file\fP.SH DESCRIPTIONSPIM S20 is a simulator that runs programs for the MIPS R2000/R3000RISC computers. (For a description of the real machines, see GerryKane and Joe Heinrich, \fIMIPS RISC Architecture,\fP Prentice Hall,1992.) SPIM can read and immediately execute files containing assemblylanguage or MIPS executable files.  SPIM is a self-contained systemfor running these programs and contains a debugger and interface to afew operating system services..PPSPIM comes in two versions.  The plain version is called \fIspim\fP.It runs on any type of terminal.  It operates like most programs ofthis type: you type a line of text, hit the \fIreturn\fP key, and\fIspim\fP executes your command.  The fancier version of SPIM iscalled \fIxspim\fP.  It uses the X-window system, so you must have abit-mapped display to run it.  \fIxspim\fP, however, is a much easierprogram to learn and use because its commands are always visible onthe screen and because it continually displays the machine'sregisters..SH OPTIONS\fIxspim\fP has many options:.IP \fB-asm\fP 10Simulate the virtual MIPS machine provided by the assembler.  This isthe default..IP \fB-bare\fP 10Simulate a bare MIPS machine without pseudo-instructions or theadditional addressing modes provided by the assembler.  Implies\fI-quiet\fP..IP \fB-trap\fP 10Load the standard exception handler and startup code.  This is the default..IP \fB-notrap\fP 10Do not load the standard exception handler and startup code.  Thisexception handler handles exceptions.  When an exception occurs, SPIMjumps to location 0x80000080, which must contain code to service theexception.  In addition, this file contains startup code that invokesthe routine \fImain\fP.  Without the startup routine, SPIM beginsexecution at the instruction labeled \fI__start\fP..IP \fB-quiet\fP 10Print a message when an exception occurs.  This is the default..IP \fB-noquiet\fP 10Do not print a message at exceptions..IP \fB-mapped_io\fP 10Enable the memory-mapped IO facility.  Programs that use SPIM syscallsto read from the terminal \fBcannot\fP also use memory-mapped IO..IP \fB-nomapped_io\fP 10Disable the memory-mapped IO facility..IP \fB-delayed_branches\fP 10Simulate MIPS's delayed control transfers by executing the instruction aftera branch, jump, or call before transferring control.  SPIM's default is tosimulate non-delayed transfers, unless the -bare flag is set..IP \fB-delayed_loads\fP 10Simulate MIPS's original, non-interlocked load instructions.  SPIM's defaultis to simulate non-delayed loads, unless the -bare flag is set..IP "\fB-stext size\fP \fB-sdata size\fP \fB-sstack size\fP \fB-sktext size\fP \fB-skdata size\fP" 10Sets the initial size of memory segment \fPseg\fP to be \fIsize\fPbytes.  The memory segments are named: \fItext\fP, \fIdata\fP,\fIstack\fP, \fIktext\fP, and \fIkdata\fP.  The \fItext\fP segmentcontains instructions from a program.  The \fIdata\fP segment holdsthe program's data.  The \fIstack\fP segment holds its runtime stack.In addition to running a program, SPIM also executes system code thathandles interrupts and exceptions.  This code resides in a separatepart of the address space called the \fIkernel\fP.  The \fIktext\fPsegment holds this code's instructions and \fIkdata\fP holds its data.There is no \fIkstack\fP segment since the system code uses the samestack as the program.  For example, the pair of arguments \fI-sdata2000000\fP starts the user data segment at 2,000,000 bytes..IP "\fB-ldata size\fP \fB-lstack size\fP  \fB-lkdata size\fP" 10Sets the limit on how large memory segment \fIseg\fP can grow to be\fIsize\fP bytes.  The memory segments that can grow are \fIdata\fP,\fIstack\fP, and \fIkdata\fP..IP \fB-hexgpr\fP 10Disply the general purpose registers (GPRs) in hexadecimal..IP \fB-nohexgpr\fP 10Disply the general purpose registers (GPRs) in decimal..IP \fB-hexfpr\fP 10Disply the floating-point registers (FPRs) in hexadecimal..IP \fB-nohexfpr\fP 10Disply the floating-point registers (FPRs) as floating-point values.IP "\fB-file file\fP 10"Load and execute the assembly code in the file..IP "\fB-execute file\fP 10"Load and execute the MIPS \fIexecutable\fP (a.out) file.  Only workson systems using a MIPS processors..SH "BUGS"Instruction opcodes cannot be used as labels..SH "SEE ALSO"spim(1).brJames R. Larus, ``SPIM S20: A MIPS R2000 Simulator,''included with SPIM distribution..SH AUTHORJames R. Larus (larus@cs.wisc.edu), Computer Sciences Department,University of Wisconsin\-Madison.Current address: James R Larus (larus@microsoft.com), Microsoft Research.