iderwsectorscommand.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 53 行

/*
 * $Id: IDERWSectorsCommand.java,v 1.1 2003/11/25 11:50:42 epr Exp $
 */
package org.jnode.driver.ide;

/**
 * IDE Read and Write common initialization code 
 * @author gbin
 */
public abstract class IDERWSectorsCommand extends IDECommand {
	protected final long lbaStart;
	protected final int sectors;

	public IDERWSectorsCommand(
		int taskfile,
		boolean master,
		long lbaStart,
		int sectors) {
		super(taskfile, master);
		this.lbaStart = lbaStart;
		this.sectors = sectors;
		if ((sectors < 1) || (sectors > 256)) {
			throw new IllegalArgumentException("Sectors must be between 1 and 256");
		}
	}

	protected void setup(IDEBus ide) {
		final int select;
		final int sectors;
		final int lbaLow = (int) (lbaStart & 0xFF);
		final int lbaMid = (int) ((lbaStart >> 8) & 0xFF);
		final int lbaHigh = (int) ((lbaStart >> 16) & 0xFF);
		final int lbaRem = (int) ((lbaStart >> 24) & 0x0F);
		if (master) {
			select = lbaRem | SEL_BLANK | SEL_LBA | SEL_DRIVE_MASTER;
		} else {
			select = lbaRem | SEL_BLANK | SEL_LBA | SEL_DRIVE_SLAVE;
		}
		if (this.sectors == 256) {
			sectors = 0;
		} else {
			sectors = this.sectors;
		}

		ide.setSectorCountReg(sectors);
		ide.setLbaLowReg(lbaLow);
		ide.setLbaMidReg(lbaMid);
		ide.setLbaHighReg(lbaHigh);
		ide.setSelectReg(select);

	}
}