Hykilpikonna
103 lines
3.8 KiB
Java
103 lines
3.8 KiB
Java
package mars.mips.instructions.syscalls;
|
|
|
|
import mars.ProcessingException;
|
|
import mars.ProgramStatement;
|
|
/*
|
|
Copyright (c) 2003-2006, Pete Sanderson and Kenneth Vollmar
|
|
|
|
Developed by Pete Sanderson (psanderson@otterbein.edu)
|
|
and Kenneth Vollmar (kenvollmar@missouristate.edu)
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining
|
|
a copy of this software and associated documentation files (the
|
|
"Software"), to deal in the Software without restriction, including
|
|
without limitation the rights to use, copy, modify, merge, publish,
|
|
distribute, sublicense, and/or sell copies of the Software, and to
|
|
permit persons to whom the Software is furnished to do so, subject
|
|
to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be
|
|
included in all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
|
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
|
|
ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
|
|
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
|
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
|
|
(MIT license, http://www.opensource.org/licenses/mit-license.html)
|
|
*/
|
|
|
|
|
|
/**
|
|
* Abstract class that a MIPS syscall system service may extend. A qualifying service must be a class in the
|
|
* mars.mips.instructions.syscalls package that implements the Syscall interface, must be compiled into a .class file,
|
|
* and its .class file must be in the same folder as Syscall.class. Mars will detect a qualifying syscall upon startup,
|
|
* create an instance using its no-argument constructor and add it to its syscall list. When its service is invoked at
|
|
* runtime ("syscall" instruction with its service number stored in register $v0), its simulate() method will be
|
|
* invoked.
|
|
*/
|
|
|
|
public abstract class AbstractSyscall implements Syscall
|
|
{
|
|
private int serviceNumber;
|
|
|
|
private final String serviceName;
|
|
|
|
/**
|
|
* Constructor is provided so subclass may initialize instance variables.
|
|
*
|
|
* @param number default assigned service number
|
|
* @param name service name which may be used for reference independent of number
|
|
*/
|
|
public AbstractSyscall(int number, String name)
|
|
{
|
|
serviceNumber = number;
|
|
serviceName = name;
|
|
}
|
|
|
|
/**
|
|
* Return the name you have chosen for this syscall. This can be used by a MARS user to refer to the service when
|
|
* choosing to override its default service number in the configuration file.
|
|
*
|
|
* @return service name as a string
|
|
*/
|
|
public String getName()
|
|
{
|
|
return serviceName;
|
|
}
|
|
|
|
/**
|
|
* Return the assigned service number. This is the number the MIPS programmer must store into $v0 before issuing
|
|
* the SYSCALL instruction.
|
|
*
|
|
* @return assigned service number
|
|
*/
|
|
public int getNumber()
|
|
{
|
|
return serviceNumber;
|
|
}
|
|
|
|
/**
|
|
* Set the service number. This is provided to allow MARS implementer or user to override the default service
|
|
* number.
|
|
*
|
|
* @param num specified service number to override the default.
|
|
*/
|
|
public void setNumber(int num)
|
|
{
|
|
serviceNumber = num;
|
|
}
|
|
|
|
/**
|
|
* Performs syscall function. It will be invoked when the service is invoked at simulation time. Service is
|
|
* identified by value stored in $v0.
|
|
*
|
|
* @param statement ProgramStatement object for this syscall instruction.
|
|
*/
|
|
public abstract void simulate(ProgramStatement statement)
|
|
throws ProcessingException;
|
|
}
|