content: package mars.mips.hardware;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  
  import mars.Globals;
  
  /*
   * Copyright (c) 2003-2009, 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)
   */
  
  /**
   * Models the collection of MIPS memory configurations. The default
   * configuration is based on SPIM. Starting with MARS 3.7, the configuration can
   * be changed.
   *
   * @author Pete Sanderson
   * @version August 2009
   */
  
  public class MemoryConfigurations {
  
  	private static ArrayList configurations = null;
  	private static MemoryConfiguration defaultConfiguration;
  	private static MemoryConfiguration currentConfiguration;
  
  	// Be careful, these arrays are parallel and position-sensitive.
  	// The getters in this and in MemoryConfiguration depend on this
  	// sequence.  Should be refactored...  The order comes from the
  	// original listed order in Memory.java, where most of these were
  	// "final" until Mars 3.7 and changeable memory configurations.
  	private static final String[] configurationItemNames = { ".text base address", "data segment base address",
  			".extern base address", "global pointer $gp", ".data base address", "heap base address",
  			"stack pointer $sp", "stack base address", "user space high address", "kernel space base address",
  			".ktext base address", "exception handler address", ".kdata base address", "MMIO base address",
  			"kernel space high address", "data segment limit address", "text limit address",
  			"kernel data segment limit address", "kernel text limit address", "stack limit address",
  			"memory map limit address" };
  
  	// Default configuration comes from SPIM
  	private static int[] defaultConfigurationItemValues = { 0x00400000, // .text Base Address
  			0x10000000, // Data Segment base address
  			0x10000000, // .extern Base Address
  			0x10008000, // Global Pointer $gp)
  			0x10010000, // .data base Address
  			0x10040000, // heap base address
  			0x7fffeffc, // stack pointer $sp (from SPIM not MIPS)
  			0x7ffffffc, // stack base address
  			0x7fffffff, // highest address in user space
  			0x80000000, // lowest address in kernel space
  			0x80000000, // .ktext base address
  			0x80000180, // exception handler address
  			0x90000000, // .kdata base address
  			0xffff0000, // MMIO base address
  			0xffffffff, // highest address in kernel (and memory)
  			0x7fffffff, // data segment limit address
  			0x0ffffffc, // text limit address
  			0xfffeffff, // kernel data segment limit address
  			0x8ffffffc, // kernel text limit address
  			0x10040000, // stack limit address
  			0xffffffff  // memory map limit address
  	};
  
  	// Compact allows 16 bit addressing, data segment starts at 0
  	private static int[] dataBasedCompactConfigurationItemValues = { 0x00003000, // .text Base Address
  			0x00000000, // Data Segment base address
  			0x00001000, // .extern Base Address
  			0x00001800, // Global Pointer $gp)
  			0x00000000, // .data base Address
  			0x00002000, // heap base address
  			0x00002ffc, // stack pointer $sp 
  			0x00002ffc, // stack base address
  			0x00003fff, // highest address in user space
  			0x00004000, // lowest address in kernel space
  			0x00004000, // .ktext base address
  			0x00004180, // exception handler address
  			0x00005000, // .kdata base address
  			0x00007f00, // MMIO base address
  			0x00007fff, // highest address in kernel (and memory)
  			0x00002fff, // data segment limit address
  			0x00003ffc, // text limit address
  			0x00007eff, // kernel data segment limit address
  			0x00004ffc, // kernel text limit address
  			0x00002000, // stack limit address
  			0x00007fff  // memory map limit address
  	};
  
  	// Compact allows 16 bit addressing, text segment starts at 0
  	private static int[] textBasedCompactConfigurationItemValues = { 0x00000000, // .text Base Address
  			0x00001000, // Data Segment base address
  			0x00001000, // .extern Base Address
  			0x00001800, // Global Pointer $gp)
  			0x00002000, // .data base Address
  			0x00003000, // heap base address
  			0x00003ffc, // stack pointer $sp 
  			0x00003ffc, // stack base address
  			0x00003fff, // highest address in user space
  			0x00004000, // lowest address in kernel space
  			0x00004000, // .ktext base address
  			0x00004180, // exception handler address
  			0x00005000, // .kdata base address
  			0x00007f00, // MMIO base address
  			0x00007fff, // highest address in kernel (and memory)
  			0x00003fff, // data segment limit address
  			0x00000ffc, // text limit address
  			0x00007eff, // kernel data segment limit address
  			0x00004ffc, // kernel text limit address
  			0x00003000, // stack limit address
  			0x00007fff  // memory map limit address
  	};
  
  	public MemoryConfigurations() {
  
  	}
  
  	public static void buildConfigurationCollection() {
  		if (configurations == null) {
  			configurations = new ArrayList();
  			configurations.add(new MemoryConfiguration("Default", "Default", configurationItemNames,
  					defaultConfigurationItemValues));
  			configurations.add(new MemoryConfiguration("CompactDataAtZero", "Compact, Data at Address 0",
  					configurationItemNames, dataBasedCompactConfigurationItemValues));
  			configurations.add(new MemoryConfiguration("CompactTextAtZero", "Compact, Text at Address 0",
  					configurationItemNames, textBasedCompactConfigurationItemValues));
  			defaultConfiguration = (MemoryConfiguration) configurations.get(0);
  			currentConfiguration = defaultConfiguration;
  			// Get current config from settings
  			//String currentConfigurationIdentifier = Globals.getSettings().getMemoryConfiguration();
  			setCurrentConfiguration(getConfigurationByName(Globals.getSettings().getMemoryConfiguration()));
  			//	Iterator configurationsIterator = getConfigurationsIterator();
  			//	while (configurationsIterator.hasNext()) {
  			//  MemoryConfiguration config = (MemoryConfiguration)configurationsIterator.next();
  			//	  if (currentConfigurationIdentifier.equals(config.getConfigurationIdentifier())) {
  			//	     setCurrentConfiguration(config);
  			//			}
  			//	   }
  		}
  	}
  
  	public static Iterator getConfigurationsIterator() {
  		if (configurations == null) { buildConfigurationCollection(); }
  		return configurations.iterator();
  
  	}
  
  	public static MemoryConfiguration getConfigurationByName(final String name) {
  		final Iterator configurationsIterator = getConfigurationsIterator();
  		while (configurationsIterator.hasNext()) {
  			final MemoryConfiguration config = (MemoryConfiguration) configurationsIterator.next();
  			if (name.equals(config.getConfigurationIdentifier())) { return config; }
  		}
  		return null;
  	}
  
  	public static MemoryConfiguration getDefaultConfiguration() {
  		if (defaultConfiguration == null) { buildConfigurationCollection(); }
  		return defaultConfiguration;
  	}
  
  	public static MemoryConfiguration getCurrentConfiguration() {
  		if (currentConfiguration == null) { buildConfigurationCollection(); }
  		return currentConfiguration;
  	}
  
  	public static boolean setCurrentConfiguration(final MemoryConfiguration config) {
  		if (config == null) { return false; }
  		if (config != currentConfiguration) {
  			currentConfiguration = config;
  			Globals.memory.clear();
  			RegisterFile.getUserRegister("$gp").changeResetValue(config.getGlobalPointer());
  			RegisterFile.getUserRegister("$sp").changeResetValue(config.getStackPointer());
  			RegisterFile.getProgramCounterRegister().changeResetValue(config.getTextBaseAddress());
  			RegisterFile.initializeProgramCounter(config.getTextBaseAddress());
  			RegisterFile.resetRegisters();
  			return true;
  		} else {
  			return false;
  		}
  	}
  
  	////  Use these to intialize Memory static variables at launch
  
  	public static int getDefaultTextBaseAddress() { return defaultConfigurationItemValues[0]; }
  
  	public static int getDefaultDataSegmentBaseAddress() { return defaultConfigurationItemValues[1]; }
  
  	public static int getDefaultExternBaseAddress() { return defaultConfigurationItemValues[2]; }
  
  	public static int getDefaultGlobalPointer() { return defaultConfigurationItemValues[3]; }
  
  	public static int getDefaultDataBaseAddress() { return defaultConfigurationItemValues[4]; }
  
  	public static int getDefaultHeapBaseAddress() { return defaultConfigurationItemValues[5]; }
  
  	public static int getDefaultStackPointer() { return defaultConfigurationItemValues[6]; }
  
  	public static int getDefaultStackBaseAddress() { return defaultConfigurationItemValues[7]; }
  
  	public static int getDefaultUserHighAddress() { return defaultConfigurationItemValues[8]; }
  
  	public static int getDefaultKernelBaseAddress() { return defaultConfigurationItemValues[9]; }
  
  	public static int getDefaultKernelTextBaseAddress() { return defaultConfigurationItemValues[10]; }
  
  	public static int getDefaultExceptionHandlerAddress() { return defaultConfigurationItemValues[11]; }
  
  	public static int getDefaultKernelDataBaseAddress() { return defaultConfigurationItemValues[12]; }
  
  	public static int getDefaultMemoryMapBaseAddress() { return defaultConfigurationItemValues[13]; }
  
  	public static int getDefaultKernelHighAddress() { return defaultConfigurationItemValues[14]; }
  
  	public int getDefaultDataSegmentLimitAddress() { return defaultConfigurationItemValues[15]; }
  
  	public int getDefaultTextLimitAddress() { return defaultConfigurationItemValues[16]; }
  
  	public int getDefaultKernelDataSegmentLimitAddress() { return defaultConfigurationItemValues[17]; }
  
  	public int getDefaultKernelTextLimitAddress() { return defaultConfigurationItemValues[18]; }
  
  	public int getDefaultStackLimitAddress() { return defaultConfigurationItemValues[19]; }
  
  	public int getMemoryMapLimitAddress() { return defaultConfigurationItemValues[20]; }
  
  }
  