Package mars.mips.instructions.syscalls

Class SyscallOpen

java.lang.Object

mars.mips.instructions.syscalls.AbstractSyscall

mars.mips.instructions.syscalls.SyscallOpen

All Implemented Interfaces:

Syscall

public class SyscallOpen
extends AbstractSyscall

Service to open file name specified by $a0. File descriptor returned in $v0. (This was changed from $a0 in MARS 3.7 for SPIM compatibility. The table in the Computer Organization and Design book erroneously shows $a0.)

Constructor Summary

Constructors

Constructor	Description
SyscallOpen()	Build an instance of the syscall with its default service number and name.

Method Summary

Modifier and Type	Method	Description
void	simulate(BasicStatement statement)	Performs syscall function to open file name specified by $a0.

Methods inherited from class mars.mips.instructions.syscalls.AbstractSyscall

getName, getNumber, setNumber

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SyscallOpen

public SyscallOpen()

Build an instance of the syscall with its default service number and name.

Method Details

simulate

public void simulate(BasicStatement statement)
              throws SimulatorException

Performs syscall function to open file name specified by $a0. File descriptor returned in $v0. Only supported flags ($a1) are read-only (0), write-only (1) and write-append (9). write-only flag creates file if it does not exist, so it is technically write-create. write-append will start writing at end of existing file. Mode ($a2) is ignored.

Specified by:

simulate in interface Syscall

Specified by:

simulate in class AbstractSyscall

Parameters:

statement - BasicStatement object for this syscall instruction.

Throws:

SimulatorException