alignmentcheckedaddressspace.java

JPC: x86 PC Hardware Emulator. 牛津大学开发的一个纯JAVA的x86系统结构硬件模拟器。

/*
    JPC: A x86 PC Hardware Emulator for a pure Java Virtual Machine
    Release Version 2.0

    A project from the Physics Dept, The University of Oxford

    Copyright (C) 2007 Isis Innovation Limited

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License version 2 as published by
    the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
    Details (including contact information) can be found at: 

    www.physics.ox.ac.uk/jpc
*/

package org.jpc.emulator.memory;

import org.jpc.emulator.memory.codeblock.*;
import org.jpc.emulator.processor.*;

public class AlignmentCheckedAddressSpace extends AddressSpace
{
    private static final ProcessorException ALIGNMENT_CHECK_EXCEPTION = new ProcessorException(Processor.PROC_EXCEPTION_AC, 0, true);
    private static final ProcessorException ALIGNMENT_CHECK_EXCEPTION_GP = new ProcessorException(Processor.PROC_EXCEPTION_GP, 0, true);
    
    private AddressSpace addressSpace;

    public AlignmentCheckedAddressSpace(AddressSpace target)
    {
        addressSpace = target;
    }

    public Memory getReadMemoryBlockAt(int offset)
    {
	return addressSpace.getReadMemoryBlockAt(offset);
    }

    public Memory getWriteMemoryBlockAt(int offset)
    {
	return addressSpace.getWriteMemoryBlockAt(offset);
    }

    void replaceBlocks(Memory oldBlock, Memory newBlock)
    {
	throw new IllegalStateException("Invalid Operation");
    }

    public int execute(Processor cpu, int offset)
    {
	throw new IllegalStateException("Invalid Operation");
    }

    public CodeBlock decodeCodeBlockAt(Processor cpu, int offset)
    {
	throw new IllegalStateException("Invalid Operation");
    }


    public boolean updated()
    {
        return true;
    }

    public void clear()
    {
	addressSpace.clear();
    }

    public byte getByte(int offset)
    {
	return addressSpace.getByte(offset);
    }

    public void setByte(int offset, byte data)
    {
	addressSpace.setByte(offset, data);
    }

    public short getWord(int offset)
    {
	if ((offset & 0x1) != 0)
	    throw ALIGNMENT_CHECK_EXCEPTION;

	return addressSpace.getWord(offset);
    }

    public int getDoubleWord(int offset)
    {
	if ((offset & 0x3) != 0)
	    throw ALIGNMENT_CHECK_EXCEPTION;

	return addressSpace.getDoubleWord(offset);
    }

    public long getQuadWord(int offset)
    {
	if ((offset & 0x7) != 0)
	    throw ALIGNMENT_CHECK_EXCEPTION;

	return addressSpace.getQuadWord(offset);
    }

    public long getLowerDoubleQuadWord(int offset)
    {
	if ((offset & 0xF) != 0)
	    throw ALIGNMENT_CHECK_EXCEPTION;

	return addressSpace.getLowerDoubleQuadWord(offset);
    }

    public long getUpperDoubleQuadWord(int offset)
    {
	return addressSpace.getUpperDoubleQuadWord(offset);
    }

    public void setWord(int offset, short data)
    {
	if ((offset & 0x1) != 0)
	    throw ALIGNMENT_CHECK_EXCEPTION;

	addressSpace.setWord(offset, data);
    }

    public void setDoubleWord(int offset, int data)
    {
	if ((offset & 0x3) != 0)
	    throw ALIGNMENT_CHECK_EXCEPTION;

	addressSpace.setDoubleWord(offset, data);
    }
    
    public void setQuadWord(int offset, long data)
    {
	if ((offset & 0x7) != 0)
	    throw ALIGNMENT_CHECK_EXCEPTION;

        addressSpace.setQuadWord(offset, data);
    }

    public void setLowerDoubleQuadWord(int offset, long data)
    {
	if ((offset & 0xF) != 0)
	    throw ALIGNMENT_CHECK_EXCEPTION_GP;

        addressSpace.setLowerDoubleQuadWord(offset, data);
    }

    public void setUpperDoubleQuadWord(int offset, long data)
    {
        addressSpace.setUpperDoubleQuadWord(offset, data);
    }

    public void copyContentsFrom(int address, byte[] buffer, int off, int len)
    {
	addressSpace.copyContentsFrom(address, buffer, off, len);
    }

    public void copyContentsInto(int address, byte[] buffer, int off, int len)
    {
	addressSpace.copyContentsInto(address, buffer, off, len);
    }
}