org/jpc/emulator/motherboard/SystemBIOS.java

   1 /*
   2     JPC-RR: A x86 PC Hardware Emulator
   3     Release 1
   4
   5     Copyright (C) 2007-2009 Isis Innovation Limited
   6     Copyright (C) 2009 H. Ilari Liusvaara
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License version 2 as published by
  10     the Free Software Foundation.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License along
  18     with this program; if not, write to the Free Software Foundation, Inc.,
  19     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20
  21     Based on JPC x86 PC Hardware emulator,
  22     A project from the Physics Dept, The University of Oxford
  23
  24     Details about original JPC can be found at:
  25
  26     www-jpc.physics.ox.ac.uk
  27
  28 */
  29
  30 package org.jpc.emulator.motherboard;
  31
  32 import java.io.*;
  33 import org.jpc.emulator.*;
  34
  35 /**
  36  * This class provides a <code>Bios</code> implementation for the emulated
  37  * machines system bios. The system bios is loaded so that it runs up to address
  38  * 0x100000 (1M).
  39  * <p>
  40  * IO ports <code>0x400-0x403</code> are registered for debugging output.  Byte
  41  * writes cause ASCII characters to be written to standard output, and word
  42  * writes indicate a BIOS panic at the written value line number.
  43  * <p>
  44  * IO port <code>0x8900</code> is registered for system shutdown requests.
  45  * Currently this triggers a debugging output, but does not actually shutdown
  46  * the machine.
  47  * @author Chris Dennis
  48  */
  49 public class SystemBIOS extends Bios implements IOPortCapable
  50 {
  51     private boolean ioportRegistered;
  52
  53     /**
  54      * Loads the system bios from the resource <code>image</code>.
  55      * @param image system bios resource name.
  56      * @throws java.io.IOException propogated from the resource load.
  57      * @throws java.util.MissingResourceException propogated from the resource load
  58      */
  59     public SystemBIOS(String image) throws IOException
  60     {
  61         super(image);
  62         ioportRegistered = false;
  63     }
  64
  65     public void dumpStatusPartial(StatusDumper output)
  66     {
  67         super.dumpStatusPartial(output);
  68         output.println("\tioportRegistered " + ioportRegistered);
  69     }
  70
  71     public void dumpStatus(StatusDumper output)
  72     {
  73         if(output.dumped(this))
  74             return;
  75
  76         output.println("#" + output.objectNumber(this) + ": SystemBIOS:");
  77         dumpStatusPartial(output);
  78         output.endObject();
  79     }
  80
  81     public void dumpSRPartial(SRDumper output) throws IOException
  82     {
  83         super.dumpSRPartial(output);
  84         output.dumpBoolean(ioportRegistered);
  85     }
  86
  87     public SystemBIOS(SRLoader input) throws IOException
  88     {
  89         super(input);
  90         ioportRegistered = input.loadBoolean();
  91     }
  92
  93     public int[] ioPortsRequested()
  94     {
  95         return new int[]{0x400, 0x401, 0x402, 0x403, 0x8900};
  96     }
  97
  98     public void ioPortWriteByte(int address, int data)
  99     {
 100         switch (address) {
 101             /* Bochs BIOS Messages */
 102             case 0x402:
 103             case 0x403:
 104                 print(data);
 105                 break;
 106             case 0x8900:
 107                 System.err.println("Emulated: attempted system shutdown");
 108                 break;
 109             default:
 110         }
 111     }
 112
 113     public void ioPortWriteWord(int address, int data)
 114     {
 115         switch (address) {
 116             /* Bochs BIOS Messages */
 117             case 0x400:
 118             case 0x401:
 119                 System.err.println("Emulated CRITICAL: panic in rombios.c at line " + data + ".");
 120         }
 121     }
 122
 123     public int ioPortReadByte(int address)
 124     {
 125         return 0xff;
 126     }
 127
 128     public int ioPortReadWord(int address)
 129     {
 130         return 0xffff;
 131     }
 132
 133     public int ioPortReadLong(int address)
 134     {
 135         return 0xffffffff;
 136     }
 137
 138     public void ioPortWriteLong(int address, int data)
 139     {
 140     }
 141
 142     protected int loadAddress()
 143     {
 144         return 0x100000 - length();
 145     }
 146
 147     public boolean initialised()
 148     {
 149         return super.initialised() && ioportRegistered;
 150     }
 151
 152     public void acceptComponent(HardwareComponent component)
 153     {
 154         super.acceptComponent(component);
 155
 156         if ((component instanceof IOPortHandler) && component.initialised()) {
 157             ((IOPortHandler) component).registerIOPortCapable(this);
 158             ioportRegistered = true;
 159         }
 160     }
 161
 162     public void reset()
 163     {
 164         super.reset();
 165         ioportRegistered = false;
 166     }
 167 }