/*
JPC: An x86 PC Hardware Emulator for a pure Java Virtual Machine
Release Version 2.4
A project from the Physics Dept, The University of Oxford
Copyright (C) 2007-2010 The University of Oxford
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:
jpc.sourceforge.net
or the developer website
sourceforge.net/projects/jpc/
Conceived and Developed by:
Rhys Newman, Ian Preston, Chris Dennis
End of licence header
*/
package org.jpc.emulator.memory;
import org.jpc.emulator.execution.codeblock.CodeBlockManager;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Provides an Eprom memory implementation which shadows another page depending on permissions.
* <p>
* @author Ian Preston
*/
public class ShadowEPROMMemory extends EPROMMemory
{
private static final Logger LOGGING = Logger.getLogger(ShadowEPROMMemory.class.getName());
private final Memory rom;
/**
* Constructs a <code>size</code> byte long instance with backing from rom
* @param rom the backing memory
* @param size length of the instance.
*/
public ShadowEPROMMemory(int size, Memory rom, CodeBlockManager manager)
{
super(size, manager);
this.rom = rom;
}
public byte getByte(int offset)
{
if (readable())
return super.getByte(offset);
else
return rom.getByte(offset);
}
public short getWord(int offset)
{
if (readable())
return super.getWord(offset);
else
return rom.getWord(offset);
}
public int getDoubleWord(int offset)
{
if (readable())
return super.getDoubleWord(offset);
else
return rom.getDoubleWord(offset);
}
public void copyContentsIntoArray(int address, byte[] buffer, int off, int len)
{
if (readable())
super.copyContentsIntoArray(address, buffer, off, len);
else
rom.copyContentsIntoArray(address, buffer, off, len);
}
public String toString()
{
return "Shadow EPROM Memory [" + getSize() + "]";
}
}