idereadsectorscommand.java

来自「纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统」· Java 代码 · 共 58 行

/*
 * $Id: IDEReadSectorsCommand.java,v 1.1 2003/11/25 11:50:41 epr Exp $
 */
package org.jnode.driver.ide;

/**
 * @author epr
 */
public class IDEReadSectorsCommand extends IDERWSectorsCommand {
	
	private final byte[] data;
	
	private int readSectors;
	
	public IDEReadSectorsCommand(int taskfile, boolean master, long lbaStart, int sectors) {
		super(taskfile, master, lbaStart, sectors);
		this.data = new byte[SECTOR_SIZE * sectors];
	}

	/**
	 * @see org.jnode.driver.ide.IDECommand#setup(IDEBus)
	 */
	protected void setup(IDEBus ide) {
      super.setup(ide);
      ide.setCommandReg(CMD_READ);
	}

	/**
	 * @see org.jnode.driver.ide.IDECommand#handleIRQ(IDEBus)
	 */
	protected void handleIRQ(IDEBus ide) {
		final int state = ide.getStatusReg();
		if ((state & ST_ERROR) != 0) {
			setError(ide.getErrorReg());
			notifyFinished();
		} else {
			final int offset = readSectors * SECTOR_SIZE;
			final byte[] data = this.data;
			for (int i = 0; i < 512; i += 2) {
				final int v = ide.getDataReg();
				data[offset + i + 0] = (byte)(v & 0xFF);
				data[offset + i + 1] = (byte)((v >> 8) & 0xFF);
			}
			readSectors++;
			if (readSectors == sectors) {
				notifyFinished();
			}
		}
	}
	
	/**
	 * Gets the data that has been read
	 */
	public byte[] getData() {
		return data;
	}
}