DsrManager.java

/*
  DsrManager.java

  (c) 2008-2015 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.machine.ti99.dsr;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;

import ejs.base.properties.IPersistable;
import ejs.base.settings.ISettingSection;
import v9t9.common.asm.BaseMachineOperand;
import v9t9.common.cpu.ChangeBlock;
import v9t9.common.cpu.ICpuState;
import v9t9.common.dsr.IDsrHandler;
import v9t9.common.dsr.IDsrManager;
import v9t9.common.dsr.IMemoryTransfer;
import v9t9.common.events.NotifyEvent.Level;
import v9t9.common.machine.IMachine;
import v9t9.engine.dsr.ConsoleMemoryTransfer;
import v9t9.engine.hardware.ICruWriter;
import v9t9.engine.video.tms9918a.VdpTMS9918A;
import v9t9.machine.ti99.cpu.CpuState9900;
import v9t9.machine.ti99.machine.TI99Machine;

/**
 * @author ejs
 *
 */
public class DsrManager implements IPersistable, IDsrManager {
	private static final Logger log = Logger.getLogger(DsrManager.class);
	
	protected final IMachine machine;
	protected List<IDsrHandler> dsrs;
	
	protected IDsrHandler9900 activeDsr;

	public DsrManager(TI99Machine machine) {
		this.machine = machine;
		dsrs = new ArrayList<IDsrHandler>();
	}
	
	public void dispose() {
		for (IDsrHandler dsr : dsrs) {
			dsr.dispose();
		}
	}

	public void saveState(ISettingSection section) {
		for (IDsrHandler handler : dsrs) {
			handler.saveState(section.addSection(handler.getName()));
		}
	}

	public void loadState(ISettingSection section) {
		if (section == null) return;
		for (IDsrHandler handler : dsrs) {
			handler.loadState(section.getSection(handler.getName()));
		}
	}

	public List<IDsrHandler> getDsrs() {
		return dsrs;
	}

	public void registerDsr(IDsrHandler dsr) {
		this.dsrs.add(dsr);
		if (dsr instanceof IDsrHandler9900) {
			addDeviceCRU(((IDsrHandler9900) dsr).getCruBase(), (IDsrHandler9900) dsr);
		}
	}
	
	protected void addDeviceCRU(int addr, final IDsrHandler9900 dsr) {
		((TI99Machine)machine).getCruManager().add(addr, 1, new ICruWriter() {

			public int write(int addr, int data, int num) {
				if (data == 1) {
					try {
						dsr.activate(machine.getConsole(), machine.getMemory().getMemoryEntryFactory());
						activeDsr = dsr;
					} catch (IOException e) {
						machine.getEventNotifier().notifyEvent(machine, Level.ERROR, 
								"Could not activate " + dsr.getName() + ": " + e.getMessage());
						log.error("Could not activate " + dsr.getName(), e);
					}
				} else {
					dsr.deactivate(machine.getConsole());
					activeDsr = null;
				}
				return 0;
			}
			
		});
	}
	
	
	public void handleDSR(ICpuState cpuState, ChangeBlock changeBlock) {
		short callpc = (short) (cpuState.getPC() - 2);
		short wp = ((CpuState9900) cpuState).getWP();
		short rambase = (short) (wp - 0xe0);
		int crubase = cpuState.getRegister(12);
	
		if (callpc >= 0x4000 && callpc < 0x6000) {
			
			/*  Only respond if we have an active module whose
			   base matches that which DSRLNK is currently scanning. */
			if (activeDsr != null && ((IDsrHandler9900)activeDsr).getCruBase() == crubase) {
				//System.out.println("handling DSR: pc = "+HexUtils.toHex4(callpc)+" " + instructionWorkBlock.inst);
	
				// on success, return to DSR handler, to return an
				// error or otherwise terminate instead of continuing
				// to scan CRU bases
				
				IMemoryTransfer xfer = new ConsoleMemoryTransfer(
						cpuState.getConsole(),
						machine.getVdp(),
						((VdpTMS9918A) machine.getVdp()).getVdpMmio(),
						rambase);
				
				int retreg = wp + 11 * 2;
				short ret = cpuState.getConsole().readWord(retreg);
				short oper = (short) (((BaseMachineOperand)(changeBlock.inst.getOp1())).val);
				if (activeDsr.handleDSR(xfer, oper)) {
					// success: skip next word (handling error)
					ret += 2;
				}
				cpuState.getConsole().writeWord(retreg, ret);
				cpuState.setPC(ret);
			}
		}
	}
}