Package mars.mips.instructions.syscalls

Class SyscallRead

java.lang.Object

mars.mips.instructions.syscalls.AbstractSyscall

mars.mips.instructions.syscalls.SyscallRead

All Implemented Interfaces:

Syscall

public class SyscallRead
extends AbstractSyscall

Service to read from file descriptor given in $a0. $a1 specifies buffer and $a2 specifies length. Number of characters read is returned in $v0. (this was changed from $a0 in MARS 3.7 for SPIM compatibility. The table in COD erroneously shows $a0). *

Constructor Summary

Constructors

Constructor	Description
SyscallRead()	Build an instance of the Read file syscall.

Method Summary

Modifier and Type	Method	Description
void	simulate(ProgramStatement statement)	Performs syscall function to read from file descriptor given in $a0.

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

getName, getNumber, setNumber

Methods inherited from class java.lang.Object

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

Constructor Details

SyscallRead

public SyscallRead()

Build an instance of the Read file syscall. Default service number is 14 and name is "Read".

Method Details

simulate

public void simulate(ProgramStatement statement)
              throws ProcessingException

Performs syscall function to read from file descriptor given in $a0. $a1 specifies buffer and $a2 specifies length. Number of characters read is returned in $v0 (starting MARS 3.7).

Specified by:

simulate in interface Syscall

Specified by:

simulate in class AbstractSyscall

Parameters:

statement - ProgramStatement object for this syscall instruction.

Throws:

ProcessingException