/* ES40 emulator.
 * Copyright (C) 2007-2008 by the ES40 Emulator Project
 *
 * WWW    : http://www.es40.org
 * E-mail : camiel@es40.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * Although this is not required, the author would appreciate being
 * notified of, and receiving any modifications you may make to the
 * source code that might serve the general public.
 */

 /**
  * \file
  * Contains the code for the emulated Ali M1543C IDE chipset part.
  *
  * $Id$
  *
  * X-1.34       Camiel Vanderhoeven                             31-MAY-2008
  *      Changes to include parts of Poco.
  *
  * X-1.33       Camiel Vanderhoeven                             29-APR-2008
  *      CDiskController is no longer a CPCIDevice. devices that are both
  *      should multiple inherit both.
  *
  * X-1.32       Brian Wheeler                                   04-APR-2008
  *      Fixed missing variable declaration.
  *
  * X-1.31       Camiel Vanderhoeven                             02-APR-2008
  *      Fixed compiler warnings.
  *
  * X-1.30       Brian Wheeler                                   20-MAR-2008
  *   1. Improved locking by a) Removing all of the general register
  *      locking; b) Busmaster locking is still in place, but it might not
  *      be needed, this locking is pretty fine grained so nothing should
  *      time out waiting for it; c) Creating an alt_status variable which
  *      gets updated when the real status becomes stable (i.e. at the end
  *      of the execute() run, after the drq status is changed, etc),
  *      access to this variable is locked; d) Everything else is a free
  *      for all.
  *   3. Implement an optional delayed interrupt. The OSes still lose
  *      interrupts sometimes.
  *
  * X-1.29       Brian Wheeler                                   17-MAR-2008
  *      Fix some CD-ROM issues.
  *
  * X-1.28       Camiel Vanderhoeven                             14-MAR-2008
  *      Formatting.
  *
  * X-1.27       Camiel Vanderhoeven                             14-MAR-2008
  *   1. More meaningful exceptions replace throwing (int) 1.
  *   2. U64 macro replaces X64 macro.
  *
  * X-1.26       Camiel Vanderhoeven                             13-MAR-2008
  *      Create init(), start_threads() and stop_threads() functions.
  *
  * X-1.25       Brian Wheeler                                   12-MAR-2008
  *      Better DMA support.
  *
  * X-1.24       Camiel Vanderhoeven                             11-MAR-2008
  *      Named, debuggable mutexes.
  *
  * X-1.23       Brian Wheeler                                   11-MAR-2008
  *      Even nicer, more efficient multi-threading version.
  *
  * X-1.22       Brian Wheeler                                   05-MAR-2008
  *      Nicer, more efficient multi-threading version.
  *
  * X-1.21       Camiel Vanderhoeven                             05-MAR-2008
  *      Multi-threading version.
  *
  * X-1.20       Camiel Vanderhoeven                             04-MAR-2008
  *      Merged Brian wheeler's New IDE code into the standard controller.
  *
  * X-1.19.17    Brian Wheeler                                   27-FEB-2008
  *     Re-fire interrupts less often.
  *
  * X-1.19.16    Brian Wheeler                                   27-FEB-2008
  *     Improvement to last fix.
  *
  * X-1.19.15    Brian Wheeler                                   27-FEB-2008
  *     This patch fixes the vms boot problems from ide cdrom and it also
  *     allowed me to install tru64 -- albeit with timeouts:
  *   a) Clears the busmaster active bit when the bit 1 is written to the
  *      busmaster status register.
  *   b) Attempts to refire the interrupt if the controller seems to have
  *      missed it -- before the OS declares a timeout.
  *
  * X-1.19.14    Brian Wheeler                                   27-FEB-2008
  *      Avoid compiler warnings.
  *
  * X-1.19.13    Brian Wheeler                                   29-JAN-2008
  *      Avoid firing interrupts that occurred while interrupts were
  *      disabled.
  *
  * X-1.19.12    Camiel Vanderhoeven                             28-JAN-2008
  *      Avoid compiler warnings.
  *
  * X-1.19.11    Brian Wheeler                                   26-JAN-2008
  *      Don't repeat interrupt too soon.
  *
  * X-1.19.10    Camiel Vanderhoeven                             24-JAN-2008
  *      Use new CPCIDevice::do_pci_read and CPCIDevice::do_pci_write.
  *
  * X-1.19.9     Brian Wheeler                                   16-JAN-2008
  *      Less timeouts.
  *
  * X-1.19.8     Brian Wheeler                                   14-JAN-2008
  *      Less messages without debugging enabled.
  *
  * X-1.19.7     Fang Zhe                                        13-JAN-2008
  *      Big-endian support.
  *
  * X-1.19.6     Camiel Vanderhoeven                             12-JAN-2008
  *      Use disk's SCSI engine for ATAPI devices.
  *
  * X-1.19.5      Brian Wheeler                                   10-JAN-2008
  *   - Stop dividing get_lba_size() by 4 in ATAPI Get Capacity.  SRM can
  *     now boot cdrom images correctly, and OSes can use cdroms effectively...
  *     at least until they call an unimplemented SCSI command.
  *
  * X-1.19.4      Brian Wheeler                                   09-JAN-2008
  *   - During init, command_in_progress and command_cycle are cleared.
  *   - Writes to ide_control are processed correctly.  Tru64 & FreeBSD
  *     recognize disks now.
  *   - interrupt is deasserted when command register is written.
  *   - Removed a bunch of debugging sections.
  *   - Made it quieter if DEBUG_IDE wasn't defined -- users should no longer
  *     see Debug Pause messages.
  *   - busy is asserted if we're currently processing a packet command when
  *     drq is deasserted (i.e. when the read buffer is empty).  This lets us
  *     get back into the ATAPI state machine before the host can start
  *     messing  with the controller.
  *   - Removed pauses for port 0x3n7 -- its really a floppy port.
  *   - Remove pause when reset is being started.
  *   - packet dma flag is presented when get_status() is run.
  *   - ATAPI command 0x1e (media lock) implemented as no-op.
  *   - ATAPI command 0x43 (read TOC) implemented as a hack.
  *   - ATAPI read now uses get_block_size() for determining transfers.
  *   - ATAPI state machine goes from DP34 to DI immediately upon completion
  *     instead of redirecting through DP2.
  *   - Added ATA Command 0xc6 (Set Multiple).
  *   .
  *
  * X-1.19.3      Brian wheeler                                   08-JAN-2008
  *      ATAPI improved.
  *
  * X-1.19.2      Brian wheeler                                   08-JAN-2008
  *      Handle blocksize correctly for ATAPI.
  *
  * X-1.19.1     Brian wheeler                                   08-JAN-2008
  *      Complete rewrite of IDE controller.
  *
  * X-1.19       Fang Zhe                                        08-JAN-2008
  *      Endianess.
  *
  * X-1.18       Camiel Vanderhoeven                             06-JAN-2008
  *      Leave changing the blocksize to the disk itself.
  *
  * X-1.17       Camiel Vanderhoeven                             04-JAN-2008
  *      Less messages fprint'ed.
  *
  * X-1.16       Camiel Vanderhoeven                             02-JAN-2008
  *      Avoid compiler warnings.
  *
  * X-1.15       Camiel Vanderhoeven                             30-DEC-2007
  *      Print file id on initialization.
  *
  * X-1.14       Camiel Vanderhoeven                             29-DEC-2007
  *      Compileable with older compilers (VC 6.0). Avoid referencing
  *      uninitialized data.
  *
  * X-1.13       Camiel Vanderhoeven                             28-DEC-2007
  *      Throw exceptions rather than just exiting when errors occur.
  *
  * X-1.12       Camiel Vanderhoeven                             28-DEC-2007
  *      Keep the compiler happy.
  *
  * X-1.11       Camiel Vanderhoeven                             28-DEC-2007
  *      Only delay IDE interrupts when NO_VMS is defined. (Need to fix this
  *                properly).
  *
  * X-1.10        Camiel Vanderhoeven                             20-DEC-2007
  *      More checks if disk exists.
  *
  * X-1.9         Brian wheeler                                   19-DEC-2007
  *      Added basic ATAPI support.
  *
  * X-1.8         Brian wheeler                                   17-DEC-2007
  *      Delayed IDE interrupts. (NetBSD requirement)
  *
  * X-1.7        Camiel Vanderhoeven                             17-DEC-2007
  *      SaveState file format 2.1
  *
  * X-1.6        Camiel Vanderhoeven                             14-DEC-2007
  *      Commented out printing each IDE command.
  *
  * X-1.5        Camiel Vanderhoeven                             12-DEC-2007
  *      Use disk controller base class.
  *
  * X-1.4        Camiel Vanderhoeven                             11-DEC-2007
  *      Removed last references to ide_command[][].
  *
  * X-1.3        Camiel Vanderhoeven                             11-DEC-2007
  *      Cleanup.
  *
  * X-1.2        Camiel Vanderhoeven                             11-DEC-2007
  *      More complete IDE implementation allows NetBSD to recognize disks.
  *
  * X-1.1        Camiel Vanderhoeven                             10-DEC-2007
  *      Initial version in CVS; this part was split off from the CAliM1543C
  *      class.
  **/
#ifdef DEBUG_IDE_LOCKS
#define DEBUG_LOCKS
#endif
#include "StdAfx.h"
#include "AliM1543C_ide.h"
#include "System.h"

#include <math.h>

#include "gui/scancodes.h"
#include "gui/keymap.h"

#include "AliM1543C.h"
#include "Disk.h"

#define PAUSE(msg)           \
  do                         \
  {                          \
    printf("Debug Pause: "); \
    printf(msg);             \
    getc(stdin);             \
  } while(0);

u32 AliM1543C_ide_cfg_data[64] = {
	/*00*/ 0x522910b9,  // CFID: vendor + device
	/*04*/ 0x02800000,  // CFCS: command + status
	/*08*/ 0x0101fac1,  // CFRV: class + revision
	/*0c*/ 0x00000000,  // CFLT: latency timer + cache line size
	/*10*/ 0x000001f1,  // BAR0:
	/*14*/ 0x000003f5,  // BAR1:
	/*18*/ 0x00000171,  // BAR2:
	/*1c*/ 0x00000375,  // BAR3:
	/*20*/ 0x0000f001,  // BAR4:
	/*24*/ 0x00000000,  // BAR5:
	/*28*/ 0x00000000,  // CCIC: CardBus
	/*2c*/ 0x00000000,  // CSID: subsystem + vendor
	/*30*/ 0x00000000,  // BAR6: expansion rom base
	/*34*/ 0x00000000,  // CCAP: capabilities pointer
	/*38*/ 0x00000000,
	/*3c*/ 0x040201ff,  // CFIT: interrupt configuration
	0, 0,
	/*48*/ 0x4a000000,  // UDMA test
	/*4c*/ 0x1aba0000,  // reserved
	0,
	/*54*/ 0x44445555,  // udma setting + fifo treshold
	0, 0, 0, 0, 0, 0, 0, 0,
	/*78*/ 0x00000021,  // ide clock
	0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

u32 AliM1543C_ide_cfg_mask[64] = {
	/*00*/ 0x00000000,  // CFID: vendor + device
	/*04*/ 0x00000105,  // CFCS: command + status
	/*08*/ 0x00000000,  // CFRV: class + revision
	/*0c*/ 0x0000ffff,  // CFLT: latency timer + cache line size
	/*10*/ 0xfffffff8,  // BAR0
	/*14*/ 0xfffffffc,  // BAR1: CBMA
	/*18*/ 0xfffffff8,  // BAR2:
	/*1c*/ 0xfffffffc,  // BAR3:
	/*20*/ 0xfffffff0,  // BAR4:
	/*24*/ 0x00000000,  // BAR5:
	/*28*/ 0x00000000,  // CCIC: CardBus
	/*2c*/ 0x00000000,  // CSID: subsystem + vendor
	/*30*/ 0x00000000,  // BAR6: expansion rom base
	/*34*/ 0x00000000,  // CCAP: capabilities pointer
	/*38*/ 0x00000000,
	/*3c*/ 0x000000ff,  // CFIT: interrupt configuration
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/**
 * Constructor.
 **/
CAliM1543C_ide::CAliM1543C_ide(CConfigurator* cfg, CSystem* c, int pcibus, int pcidev)
	: CPCIDevice(cfg, c, pcibus, pcidev),
	CDiskController(2, 2)
{
	if (theIDE != 0)
		FAILURE(Configuration, "More than one IDE controller");
	theIDE = this;

	// create scsi busses
	CSCSIBus* a = new CSCSIBus(cfg, c);
	CSCSIBus* b = new CSCSIBus(cfg, c);
	scsi_register(0, a, 7); // scsi id 7 by default
	scsi_register(1, b, 7); // scsi id 7 by default
}

/**
 * Initialize the IDE device.
 **/
void CAliM1543C_ide::init()
{
	add_function(0, AliM1543C_ide_cfg_data, AliM1543C_ide_cfg_mask);

	add_legacy_io(PRI_COMMAND, 0x1f0, 8);
	// In compatibility mode the control block is the alternate-status/device-control
	// port at 3F6h; 3F7h remains available to the legacy floppy path.
	add_legacy_io(PRI_CONTROL, 0x3f6, 1);
	add_legacy_io(SEC_COMMAND, 0x170, 8);
	add_legacy_io(SEC_CONTROL, 0x376, 1);
	add_legacy_io(PRI_BUSMASTER, 0xf000, 8);
	add_legacy_io(SEC_BUSMASTER, 0xf008, 8);

	usedma = myCfg->get_bool_value("dma", true);
	if (!usedma)
	{
		printf("IDE: DMA Transfers turned off.\n");
	}

	ResetPCI();

	// start controller threads
	StopThread = false;
	mtRegisters[0] = new CRWLock("ide0-registers");
	mtRegisters[1] = new CRWLock("ide1-registers");
	mtBusMaster[0] = new CRWLock("ide0-busmaster");
	mtBusMaster[1] = new CRWLock("ide1-busmaster");

	for (int i = 0; i < 2; i++)
	{
		semController[i] = new CSemaphore(0, 1); // disk controller
		semBusMaster[i] = new CSemaphore(0, 1);  // bus master
		thrController[i] = 0;
	}

	printf("%%IDE-I-INIT: New IDE emulator initialized.\n");
}

void CAliM1543C_ide::start_threads()
{
	char  buffer[5];
	for (int i = 0; i < 2; i++)
	{
		if (!thrController[i])
		{
			sprintf(buffer, "ide%d", i);
			thrController[i] = new CThread(buffer);
			printf(" %s", thrController[i]->getName().c_str());
			StopThread = false;
			thrController[i]->start(*this);
		}
	}
}

void CAliM1543C_ide::stop_threads()
{
	StopThread = true;
	for (int i = 0; i < 2; i++)
	{
		if (thrController[i])
		{
			printf(" %s", thrController[i]->getName().c_str());
			semController[i]->set();
			thrController[i]->join();
			delete thrController[i];
			thrController[i] = 0;
		}
	}
}

CAliM1543C_ide::~CAliM1543C_ide()
{
	stop_threads();
}

void CAliM1543C_ide::ResetPCI()
{
	int i;

	int j;
	CPCIDevice::ResetPCI();

	for (i = 0; i < 2; i++)
	{
		CONTROLLER(i).bm_status = 0;
		CONTROLLER(i).selected = 0;
		for (j = 0; j < 2; j++)
		{
			REGISTERS(i, j).error = 0;
			COMMAND(i, j).command_in_progress = 0;
			COMMAND(i, j).command_cycle = 0;
			STATUS(i, j).busy = false;
			STATUS(i, j).drive_ready = false;
			STATUS(i, j).drq = false;
			STATUS(i, j).err = false;
			STATUS(i, j).index_pulse = false;
			STATUS(i, j).index_pulse_count = 0;
			STATUS(i, j).seek_complete = false;
			PER_DRIVE(i, j).multiple_size = 1;
			set_signature(i, j);
		}
	}
}

void CAliM1543C_ide::register_disk(class CDisk* dsk, int bus, int dev)
{
	CDiskController::register_disk(dsk, bus, dev);
	if (dsk->cdrom())
	{
		dsk->scsi_register(0, scsi_bus[bus], dev);
		dsk->set_atapi_mode();
	}
}

static u32  ide_magic1 = 0xB222654D;
static u32  ide_magic2 = 0xD456222C;

/**
 * Save state to a Virtual Machine State file.
 **/
int CAliM1543C_ide::SaveState(FILE* f)
{
	long  ss = sizeof(state);
	int   res;

	if ((res = CPCIDevice::SaveState(f)))
		return res;

	fwrite(&ide_magic1, sizeof(u32), 1, f);
	fwrite(&ss, sizeof(long), 1, f);
	fwrite(&state, sizeof(state), 1, f);
	fwrite(&ide_magic2, sizeof(u32), 1, f);
	printf("%s: %d bytes saved.\n", devid_string, (int)ss);
	return 0;
}

/**
 * Restore state from a Virtual Machine State file.
 **/
int CAliM1543C_ide::RestoreState(FILE* f)
{
	long    ss;
	u32     m1;
	u32     m2;
	int     res;
	size_t  r;

	if ((res = CPCIDevice::RestoreState(f)))
		return res;

	r = fread(&m1, sizeof(u32), 1, f);
	if (r != 1)
	{
		printf("%s: unexpected end of file!\n", devid_string);
		return -1;
	}

	if (m1 != ide_magic1)
	{
		printf("%s: MAGIC 1 does not match!\n", devid_string);
		return -1;
	}

	r = fread(&ss, sizeof(long), 1, f);
	if (r != 1)
	{
		printf("%s: unexpected end of file!\n", devid_string);
		return -1;
	}

	if (ss != sizeof(state))
	{
		printf("%s: STRUCT SIZE does not match!\n", devid_string);
		return -1;
	}

	r = fread(&state, sizeof(state), 1, f);
	if (r != 1)
	{
		printf("%s: unexpected end of file!\n", devid_string);
		return -1;
	}

	r = fread(&m2, sizeof(u32), 1, f);
	if (r != 1)
	{
		printf("%s: unexpected end of file!\n", devid_string);
		return -1;
	}

	if (m2 != ide_magic2)
	{
		printf("%s: MAGIC 1 does not match!\n", devid_string);
		return -1;
	}

	printf("%s: %d bytes restored.\n", devid_string, (int)ss);
	return 0;
}

/*
 * Region read/write redirection
 */
u32 CAliM1543C_ide::ReadMem_Legacy(int index, u32 address, int dsize)
{
	int channel = 0;
	switch (index)
	{
	case SEC_COMMAND:
		channel = 1;
		[[fallthrough]];
	case PRI_COMMAND:
		return ide_command_read(channel, address, dsize);

	case SEC_CONTROL:
		channel = 1;
		[[fallthrough]];
	case PRI_CONTROL:
		return ide_control_read(channel, address);

	case SEC_BUSMASTER:
		channel = 1;
		[[fallthrough]];
	case PRI_BUSMASTER:
		return ide_busmaster_read(channel, address, dsize);
	}

	return 0;
}

void CAliM1543C_ide::WriteMem_Legacy(int index, u32 address, int dsize, u32 data)
{
	int channel = 0;
	switch (index)
	{
	case SEC_COMMAND:
		channel = 1;
		[[fallthrough]];
	case PRI_COMMAND:
		ide_command_write(channel, address, dsize, data);
		break;

	case SEC_CONTROL:
		channel = 1;
		[[fallthrough]];
	case PRI_CONTROL:
		ide_control_write(channel, address, data);
		break;

	case SEC_BUSMASTER:
		channel = 1;

	case PRI_BUSMASTER:
		ide_busmaster_write(channel, address, dsize, data);
		break;
	}
}

u32 CAliM1543C_ide::ReadMem_Bar(int func, int bar, u32 address, int dsize)
{
	int channel = 0;
	switch (bar)
	{
	case BAR_SEC_COMMAND:
		channel = 1;

	case BAR_PRI_COMMAND:
		return ide_command_read(channel, address, dsize);

	case BAR_SEC_CONTROL:
		channel = 1;

	case BAR_PRI_CONTROL:

		// we have to offset by two because the BAR starts at 3f4 vs 3f6
		return ide_control_read(channel, address - 2);

	case BAR_BUSMASTER:
		if (address < 8)
			return ide_busmaster_read(0, address, dsize);
		else
			return ide_busmaster_read(1, address - 8, dsize);
	}

	return 0;
}

void CAliM1543C_ide::WriteMem_Bar(int func, int bar, u32 address, int dsize,
	u32 data)
{
	int channel = 0;
	switch (bar)
	{
	case BAR_SEC_COMMAND:
		channel = 1;
		[[fallthrough]];
	case BAR_PRI_COMMAND:
		ide_command_write(channel, address, dsize, data);
		return;

	case BAR_SEC_CONTROL:
		channel = 1;
		[[fallthrough]];
	case BAR_PRI_CONTROL:
		// we have to offset by two because the BAR starts at 3f4 vs 3f6
		ide_control_write(channel, address - 2, data);
		return;

	case BAR_BUSMASTER:
		if (address < 8)
			return ide_busmaster_write(0, address, data, dsize);
		else
			return ide_busmaster_write(1, address - 8, data, dsize);
	}
}

/*
 * Register read/write handlers
 */
u32 CAliM1543C_ide::ide_command_read(int index, u32 address, int dsize)
{
	u32 data = 0;
	if (!get_disk(index, 0) && !get_disk(index, 1))
	{

		// no disks are present, so the data lines actually float to
		// a high state, which is logical 1.
		return 0xffffffff;
	}

	switch (address)
	{
	case REG_COMMAND_DATA:
		if (!SEL_STATUS(index).drq)
		{
#ifdef DEBUG_IDE_REG_COMMAND
			printf("Reading from data buffer when data is not ready.\n");
			ide_status(index);
			PAUSE("WTF");
#endif
			break;
		}

		data = 0;

		switch (dsize)
		{
		case 32:
			data = CONTROLLER(index).data[CONTROLLER(index).data_ptr++];
			data |= CONTROLLER(index).data[CONTROLLER(index).data_ptr++] << 16;
			break;

		case 16:
			data = CONTROLLER(index).data[CONTROLLER(index).data_ptr++];
		}

		if (CONTROLLER(index).data_ptr >= CONTROLLER(index).data_size)
		{

			// there's no more to take.
			SEL_STATUS(index).drq = false;
			if (SEL_COMMAND(index).command_in_progress)
			{
				SEL_STATUS(index).busy = true;
				SEL_STATUS(index).drive_ready = false;
				UPDATE_ALT_STATUS(index);
				semController[index]->set();  // wake up the controller.
#if defined(DEBUG_IDE_MULTIPLE) || defined(DEBUG_IDE_PACKET)
				printf("Command still in progress, waking up controller.\n");
				printf("-- Packet Phase: %d\n", SEL_COMMAND(index).packet_phase);
				ide_status(index);
#endif
			}
		}

		if (CONTROLLER(index).data_ptr > IDE_BUFFER_SIZE)
		{
			printf("%%IDE-W-OVERFLOW: data pointer past end of buffer,  setting to 0.\n");
			CONTROLLER(index).data_ptr = 0;
			SEL_STATUS(index).drq = false;
			UPDATE_ALT_STATUS(index);
		}
		break;

	case REG_COMMAND_ERROR:
		data = SEL_REGISTERS(index).error;
		break;

	case REG_COMMAND_SECTOR_COUNT:
		data = SEL_REGISTERS(index).sector_count;
		break;

	case REG_COMMAND_SECTOR_NO:
		data = SEL_REGISTERS(index).sector_no;
		break;

	case REG_COMMAND_CYL_LOW:
		data = SEL_REGISTERS(index).cylinder_no & 0xff;
		break;

	case REG_COMMAND_CYL_HI:
		data = (SEL_REGISTERS(index).cylinder_no >> 8) & 0xff;
		break;

	case REG_COMMAND_DRIVE:
		data = 0x80 | (SEL_REGISTERS(index).lba_mode ? 0x40 : 0x00) | 0x20  // 512 byte sector size
			| (CONTROLLER(index).selected ? 0x10 : 0x00) | (SEL_REGISTERS(index).head_no & 0x0f);
		break;

	case REG_COMMAND_STATUS:

		// get the status and clear the interrupt.
		data = get_status(index);
		deassert_interrupt(index);
#ifdef DEBUG_IDE_INTERRUPT
		printf("%%IDE-I-INTERRUPT: Interrupt Acknowledged on %d.\n", index);
#endif
		break;
	}

#ifdef DEBUG_IDE_REG_COMMAND
	if (address != 0)
	{
		printf("%%IDE-I-REGCMD: Read from command register %d (%s) on controller %d, value: %x\n",
			address, register_names[address], index, data);
	}
#endif
	return data;
}

void CAliM1543C_ide::ide_command_write(int index, u32 address, int dsize,
	u32 data)
{
#ifdef DEBUG_IDE_REG_COMMAND
	if (address != 0)
	{
		printf("%%IDE-I-REGCMD: Write to command register %d (%s) on controller %d, value: %x\n",
			address, register_names[address], index, data);
	}

	SEL_STATUS(index).debug_status_update = true;
#endif
	switch (address)
	{
	case REG_COMMAND_DATA:
		if (!SEL_STATUS(index).drq)
		{
#ifdef DEBUG_IDE_REG_COMMAND
			printf("%%IDE-I-DATA: Unrequested data written to data port: %x\n", data);
			ide_status(index);
#endif
			break;
		}

		switch (dsize)
		{
		case 32:
			CONTROLLER(index).data[CONTROLLER(index).data_ptr++] = data & 0xffff;
			CONTROLLER(index).data[CONTROLLER(index).data_ptr++] =
				(
					data >>
					16
					) & 0xffff;
			break;

		case 16:
			CONTROLLER(index).data[CONTROLLER(index).data_ptr++] = data & 0xffff;
		}

		if (CONTROLLER(index).data_ptr >= CONTROLLER(index).data_size)
		{

			// we don't want any more.
			SEL_STATUS(index).drq = false;
			SEL_STATUS(index).busy = true;
			UPDATE_ALT_STATUS(index);
			semController[index]->set();      // wake the controller up.
		}

		if (CONTROLLER(index).data_ptr > IDE_BUFFER_SIZE)
		{
			printf("%%IDE-W-OVERFLOW: data pointer overflow,  setting to 0.\n");
			CONTROLLER(index).data_ptr = 0;
			SEL_STATUS(index).drq = false;
			UPDATE_ALT_STATUS(index);
		}
		break;

	case REG_COMMAND_FEATURES:
		REGISTERS(index, 0).features = data;
		REGISTERS(index, 1).features = data;
		break;

	case REG_COMMAND_SECTOR_COUNT:
		REGISTERS(index, 0).sector_count = REGISTERS(index, 1).sector_count = data & 0xff;
		break;

	case REG_COMMAND_SECTOR_NO:
		REGISTERS(index, 0).sector_no = REGISTERS(index, 1).sector_no = data & 0xff;
		break;

	case REG_COMMAND_CYL_LOW:
		REGISTERS(index, 0).cylinder_no = REGISTERS(index, 1).cylinder_no =
			(REGISTERS(index, 1).cylinder_no & 0xff00) |
			(data & 0xff);
		break;

	case REG_COMMAND_CYL_HI:
		REGISTERS(index, 0).cylinder_no = REGISTERS(index, 1).cylinder_no =
			(REGISTERS(index, 1).cylinder_no & 0xff) |
			((data << 8) & 0xff00);
		break;

	case REG_COMMAND_DRIVE:
		if (((data >> 4) & 1) != CONTROLLER(index).selected)
#ifdef DEBUG_IDE
			printf("Setting selected device on %d to: %d.  val=%02x\n", index,
				(data >> 4) & 1, data);
#endif
		CONTROLLER(index).selected = (data >> 4) & 1;
		REGISTERS(index, 0).head_no = REGISTERS(index, 1).head_no = data & 0x0f;
		REGISTERS(index, 0).lba_mode = REGISTERS(index, 1).lba_mode =
			(
				data >>
				6
				) & 1;

		break;

	case REG_COMMAND_COMMAND:
		deassert_interrupt(index); // interrupt is cleared on write.
		if (!SEL_DISK(index))
		{
#ifdef DEBUG_IDE
			printf("%%IDE-I-NODEV: Command to non-existing device %d.%d. cmd=%x\n",
				index, CONTROLLER(index).selected, data);
#endif
		}

		if (SEL_COMMAND(index).command_in_progress == true)
		{

			// we're already working, why is another command being issued?
#ifdef DEBUG_IDE
			printf("%%IDE-W-CIP: Command is already in progress.\n");
			PAUSE("dang it!\n");
#endif
		}

		if ((data & 0xf0) == 0x10)
			data = 0x10;

		SEL_COMMAND(index).command_in_progress = false;
		SEL_COMMAND(index).current_command = data;
#ifdef DEBUG_IDE_CMD
		printf("%%IDE-I-CMD: Command %02x issued on controller %d, disk %d.\n", data, index, CONTROLLER(index).selected);
#endif
		SEL_COMMAND(index).command_cycle = 0;
		SEL_STATUS(index).drq = false;
		UPDATE_ALT_STATUS(index);
		CONTROLLER(index).data_ptr = 0;

		if (data != 0x00)
		{
			SEL_STATUS(index).busy = true;
			UPDATE_ALT_STATUS(index);
			SEL_COMMAND(index).command_in_progress = true;
			SEL_COMMAND(index).packet_phase = PACKET_NONE;
			semController[index]->set();      // wake up the controller.
		}
		else
		{

			// this is a nop, so we cancel everything that's pending and
			// pretend that this operation got done super fast!
			if (SEL_DISK(index))
				command_aborted(index, data);
		}
		break;
	}
}

u32 CAliM1543C_ide::ide_control_read(int index, u32 address)
{
	u32 data = 0;
	switch (address)
	{
	case 0:
	{
		SCOPED_READ_LOCK(mtRegisters[index]);
		// Compute live from current status flags rather than reading the
		// cached alt_status, which only gets refreshed at UPDATE_ALT_STATUS
		// call sites and can lag the controller thread (causing SRM read
		// timeouts when busy goes false → drq true between updates).
		if (SEL_DISK(index))
		{
			data = (SEL_STATUS(index).busy ? 0x80 : 0x00)
				| (SEL_STATUS(index).drive_ready ? 0x40 : 0x00)
				| (SEL_STATUS(index).fault ? 0x20 : 0x00)
				| (SEL_STATUS(index).seek_complete ? 0x10 : 0x00)
				| (SEL_STATUS(index).drq ? 0x08 : 0x00)
				| (SEL_STATUS(index).index_pulse ? 0x02 : 0x00)
				| (SEL_STATUS(index).err ? 0x01 : 0x00);
		}
#ifdef DEBUG_IDE_REG_CONTROL
		static u32  last_data = 0;
		if (last_data != data)
		{
			printf("%%IDE-I-READCTRL: alternate status on IDE control %d: 0x%02x\n",
				index, data);
		}

		last_data = data;
#endif
	}

	break;

	case 1:

		// 3x7h drive address register. (floppy?)
		data |= (CONTROLLER(index).selected == 0) ? 1 : 2;
		data |= (SEL_REGISTERS(index).head_no) << 2;
		data = (~data) & 0xff;  // negate everything
#ifdef DEBUG_IDE_REG_CONTROL
		printf("%%IDE-I-READCTRL: drive address port on IDE control %d: 0x%02x\n",
			index, data);
#endif
		break;
	}

	return data;
}

/**
 * Write to the IDE controller control interface.
 **/
void CAliM1543C_ide::ide_control_write(int index, u32 address, u32 data)
{
	bool  prev_reset;
#ifdef DEBUG_IDE_REG_CONTROL
	printf("%%IDE-I-WRITCTRL: write port %d on IDE control %d: 0x%02x\n",
		(u32)(address), index, data);
#endif
	switch (address)
	{
	case 0:
		prev_reset = CONTROLLER(index).reset;
		CONTROLLER(index).reset = (data >> 2) & 1;
		CONTROLLER(index).disable_irq = (data >> 1) & 1;

		if (!prev_reset && CONTROLLER(index).reset)
		{
#ifdef DEBUG_IDE_REG_CONTROL
			printf("IDE reset on index %d started.\n", index);
#endif
			STATUS(index, 0).busy = true;
			STATUS(index, 0).drive_ready = false;
			STATUS(index, 0).seek_complete = true;
			STATUS(index, 0).drq = false;
			STATUS(index, 0).err = false;
			COMMAND(index, 0).current_command = 0;
			COMMAND(index, 0).command_in_progress = false;
			STATUS(index, 1).busy = true;
			STATUS(index, 1).drive_ready = false;
			STATUS(index, 1).seek_complete = true;
			STATUS(index, 1).drq = false;
			STATUS(index, 1).err = false;
			COMMAND(index, 1).current_command = 0;
			COMMAND(index, 1).command_in_progress = false;

			CONTROLLER(index).reset_in_progress = true;
			SEL_REGISTERS(index).error = 0x01;  // no error
			COMMAND(index, 0).current_command = 0;
			// Do NOT force disable_irq=false here: the OS commonly writes
			// SRST|nIEN (0x06) to suppress IRQs during reset.  Honor the
			// nIEN bit the OS just programmed two lines above.
		}
		else if (prev_reset && !CONTROLLER(index).reset)
		{
#ifdef DEBUG_IDE_REG_CONTROL
			printf("IDE reset on index %d ended.\n", index);
#endif
			STATUS(index, 0).busy = false;
			STATUS(index, 0).drive_ready = true;
			STATUS(index, 1).busy = false;
			STATUS(index, 1).drive_ready = true;
			CONTROLLER(index).reset_in_progress = false;

			set_signature(index, 0);
			set_signature(index, 1);
			CONTROLLER(index).selected = 0;   // ATA: drive 0 is selected after reset
		}
		break;

	case 1:

		// floppy?
		break;
	}
}

/**
 * Read from the IDE controller busmaster interface.
 **/
u8 CAliM1543C_ide::ide_busmaster_status(int index)
{
	u8 status = CONTROLLER(index).busmaster[2] & 0x07;

	if (usedma)
	{
		CDisk* drive0 = get_disk(index, 0);
		CDisk* drive1 = get_disk(index, 1);

		// ATAPI DMA is not reliable in this controller model: the worker can
		// block in a packet phase while the guest is still waiting for BSY to
		// drop. Keep disk DMA available, but present packet devices as PIO-only.
		if (drive0 && !drive0->cdrom())
			status |= 0x20;
		if (drive1 && !drive1->cdrom())
			status |= 0x40;
	}

	return status;
}

u32 CAliM1543C_ide::ide_busmaster_read(int index, u32 address, int dsize)
{
	u32 data = 0;
	switch (dsize)
	{
	case 8:
		if (address == 2)
			CONTROLLER(index).busmaster[2] = ide_busmaster_status(index);
		data = CONTROLLER(index).busmaster[address];
		break;

	case 32:
		CONTROLLER(index).busmaster[2] = ide_busmaster_status(index);
		data = *(u32*)(&CONTROLLER(index).busmaster[address]);
		break;

	default:
		FAILURE(InvalidArgument, "16-bit read from busmaster");
		break;
	}

#ifdef DEBUG_IDE_BUSMASTER
	printf("%%IDE-I-READBUSM: read port %d on IDE bus master %d: 0x%02x, %d bytes\n",
		(u32)(address), index, data, dsize / 8);
#endif
	return data;
}

/**
 * Write to the IDE controller busmaster interface.
 **/
void CAliM1543C_ide::ide_busmaster_write(int index, u32 address, u32 data,
	int dsize)
{
#ifdef DEBUG_IDE_BUSMASTER
	if (!(dsize == 8 && (address >= 4 && address <= 7)))
	{
		printf("%%IDE-I-WRITBUSM: write port %d on IDE bus master %d: 0x%02x, %d bytes\n",
			(u32)(address), index, data, dsize / 8);
	}
#endif

	u32 prd_address;

	//  u32 base, control;
	switch (dsize)
	{
	case 32:
		ide_busmaster_write(index, address, data & 0xff, 8);
		ide_busmaster_write(index, address + 1, (data >> 8) & 0xff, 8);
		ide_busmaster_write(index, address + 2, (data >> 16) & 0xff, 8);
		ide_busmaster_write(index, address + 3, (data >> 24) & 0xff, 8);
		return;

	case 16:
		ide_busmaster_write(index, address, data & 0xff, 8);
		ide_busmaster_write(index, address + 1, (data >> 8) & 0xff, 8);
		return;
	}

	switch (address)
	{
	case 0: // command register
#ifdef DEBUG_IDE_BUSMASTER
		printf("%%IDE-I-BUSM: Bus master command got data: %x (%s,%s)\n", data,
			(data & 0x08 ? "write" : "read"), (data & 0x01 ? "start" : "stop"));
#endif

		// bits 7:4 & 2:1 are reserved and must return zero on read.
		CONTROLLER(index).busmaster[0] = data & 0x09;
		if (data & 0x01)
		{

			// set the status register
			CONTROLLER(index).busmaster[2] |= 0x01;
			semBusMaster[index]->set(); // wake up the controller for busmastering
		}
		else
		{

			// clear the status register
			CONTROLLER(index).busmaster[2] &= 0xfe;
		}
		break;

	case 2:           // status
		// bit 7 = simplex only (0=both channels are independent)
		// bit 6 = drive 1 dma capable.
		// bit 5 = drive 0 dma capable.
		// bit 4,3 = reserved
		// bit 2 = interrupt (write 1 to reset)
		// bit 1 = error (write 1 to reset)
		// bit 0 = busmaster active.
		{
			u8 status = CONTROLLER(index).busmaster[2];
			if (data & 0x04) // interrupt
				status &= ~0x04;
			if (data & 0x02) // error
				status &= ~0x02;
			if (data & 0x01) // active; several ALi drivers write this to work around sticky active
				status &= ~0x01;
			CONTROLLER(index).busmaster[2] = (status & 0x07) | (ide_busmaster_status(index) & 0x60);
			if ((data & 0x04) || (data & 0x01))
				deassert_interrupt(index);
		}
		break;

	case 4:           // descriptor table pointer register(s)
	case 5:
	case 6:
		CONTROLLER(index).busmaster[address] = data;
		break;

	case 7:
		CONTROLLER(index).busmaster[address] = data;
		prd_address = endian_32(*(u32*)(&CONTROLLER(index).busmaster[4]));
#ifdef DEBUG_IDE_BUSMASTER
		printf("%%IDE-I-PRD: Virtual address: %" PRIx64 "  \n",
			endian_32(*(u32*)(&CONTROLLER(index).busmaster[4])));
		printf("-IDE-I-PRD: Physical address: %" PRIx64 "  \n", prd_address);
		u32 base, control;
		do
		{
			do_pci_read(prd_address, &base, 4, 1);
			do_pci_read(prd_address + 4, &control, 4, 1);
			printf("-IDE-I-PRD: base: %x, control: %x  \n", base, control);
			prd_address += 8;
		} while ((control & 0x80000000) == 0);
#endif
		break;

	default:
		break;
	}
}

void CAliM1543C_ide::set_signature(int index, int id)
{

	// Device signature
	REGISTERS(index, id).head_no = 0;
	REGISTERS(index, id).sector_count = 1;
	REGISTERS(index, id).sector_no = 1;
	if (get_disk(index, id))
	{
		if (!get_disk(index, id)->cdrom())
		{
			REGISTERS(index, id).cylinder_no = 0;
		}
		else
		{
			REGISTERS(index, id).cylinder_no = 0xeb14;
		}
	}
	else
	{
		// No drive at this slot - registers should all float high (0xFF)
		REGISTERS(index, id).cylinder_no = 0xffff;
		REGISTERS(index, id).head_no = 0xff;
		REGISTERS(index, id).sector_count = 0xff;
		REGISTERS(index, id).sector_no = 0xff;
	}
}

// PCI IDE programming-interface bit per channel (cfg byte 0x09):
//   bit 0 = primary native, bit 2 = secondary native; 0 = compat mode.
// Compat mode:  ISA IRQ 14/15 via 8259 cascade — no PCI INTx.
// Native mode:  shared PCI INTA — no 8259 IRQ.
bool CAliM1543C_ide::channel_is_native(int index)
{
	const u8 prog_if = (endian_32(pci_state.config_data[0][0x02]) >> 8) & 0xff;
	return (prog_if >> (index ? 2 : 0)) & 1;
}

void CAliM1543C_ide::raise_interrupt(int index)
{
	if (!CONTROLLER(index).disable_irq)
	{
#ifdef DEBUG_IDE_INTERRUPT
		printf("%%IDE-I-INTERRUPT: Interrupt raised on controller %d.\n", index);
#endif

#if !defined(IDE_YIELD_INTERRUPTS)
		{
			SCOPED_WRITE_LOCK(mtBusMaster[index]);
			if (CONTROLLER(index).busmaster[0] & 0x01)
				CONTROLLER(index).busmaster[2] |= 0x04;
		}
		UPDATE_ALT_STATUS(index);
		CONTROLLER(index).interrupt_pending = true;
		if (channel_is_native(index))
			do_pci_interrupt(0, true);
		else
			theAli->pic_interrupt(1, 6 + index);
#else
		CONTROLLER(index).interrupt_pending = true;
#endif
	}
}

void CAliM1543C_ide::deassert_interrupt(int index)
{
	bool keep_asserted = false;
	{
		SCOPED_READ_LOCK(mtBusMaster[index]);
		keep_asserted =
			(CONTROLLER(index).busmaster[2] & 0x04) &&
			(CONTROLLER(index).busmaster[0] & 0x01);
	}
	if (keep_asserted)
		return;

	CONTROLLER(index).interrupt_pending = false;
	if (channel_is_native(index)) {
		// PCI INTA is shared between both channels; only drop the line
		// when neither channel still has work pending.
		if (!CONTROLLER(0).interrupt_pending && !CONTROLLER(1).interrupt_pending)
			do_pci_interrupt(0, false);
	} else {
		theAli->pic_deassert(1, 6 + index);
	}
}

u8 CAliM1543C_ide::get_status(int index)
{
	u8  data;
	if (!SEL_DISK(index))
	{
#ifdef DEBUG_IDE_REG_COMMAND
		printf("%%IDE-I-STATUS: Read status for nonexiting device %d.%d\n", index,
			CONTROLLER(index).selected);
#endif
		// Absent drive: real hardware pulls all data lines high, so the
		// host reads 0xff.
		return 0xff;
	}

	data = (SEL_STATUS(index).busy ? 0x80 : 0x00) |
		(SEL_STATUS(index).drive_ready ? 0x40 : 0x00) |
		(SEL_STATUS(index).fault ? 0x20 : 0x00) |
		(SEL_STATUS(index).seek_complete ? 0x10 : 0x00) |
		(SEL_STATUS(index).drq ? 0x08 : 0x00) |
		(SEL_STATUS(index).index_pulse ? 0x02 : 0x00) |
		(SEL_STATUS(index).err ? 0x01 : 0x00);
	SEL_STATUS(index).index_pulse_count++;
	SEL_STATUS(index).index_pulse = false;
	if (SEL_STATUS(index).index_pulse_count >= 10)
	{
		SEL_STATUS(index).index_pulse_count = 0;
		SEL_STATUS(index).index_pulse = true;
	}

#ifdef DEBUG_IDE_REG_COMMAND
	if ((SEL_STATUS(index).debug_last_status & 0xfd) != (data & 0xfd)
		|| SEL_STATUS(index).debug_status_update)
	{
		printf("%%IDE-I-STATUS: Controller %d status: %x = %s %s %s %s %s %s %s\n",
			index, data, SEL_STATUS(index).busy ? "busy" : "",
			SEL_STATUS(index).drive_ready ? "drdy" : "",
			SEL_STATUS(index).fault ? "fault" : "",
			SEL_STATUS(index).seek_complete ? "seek_complete" : "",
			SEL_STATUS(index).drq ? "drq" : "",
			SEL_STATUS(index).index_pulse ? "pulse" : "",
			SEL_STATUS(index).err ? "error" : "");
		SEL_STATUS(index).debug_status_update = false;
	}

	SEL_STATUS(index).debug_last_status = data;
#endif
	return data;
}

void CAliM1543C_ide::identify_drive(int index, bool packet)
{
	char    serial_number[21];
	char    model_number[41];
	char    rev_number[9];
	size_t  i;

	// clear the block.
	for (i = 0; i < 256; i++)
		CONTROLLER(index).data[i] = 0;

	CONTROLLER(index).data_ptr = 0;
	CONTROLLER(index).data_size = 256;

	// The data here was taken from T13/1153D revision 18
	if (!packet)
	{

		// flags:  0x0080 = removable, 0x0040 = fixed.
		CONTROLLER(index).data[0] = SEL_DISK(index)->cdrom() ? 0x0080 : 0x0040;
	}
	else
	{

		// flags: 15-14: 10=atapi, 11=reserved; 12-8: packet set; 7:
		// removable 6-5: timing info, 4-2: command, 1-0: 00= 12 byte packet
		CONTROLLER(index).data[0] = 0x8580;
	}

	// logical cylinders
	if (SEL_DISK(index)->get_cylinders() > 16383)
		CONTROLLER(index).data[1] = 16383;
	else
		CONTROLLER(index).data[1] = (u16)(SEL_DISK(index)->get_cylinders());

	// logical heads
	CONTROLLER(index).data[3] = (u16)(SEL_DISK(index)->get_heads());

	// logical sectors per logical track
	CONTROLLER(index).data[6] = (u16)(SEL_DISK(index)->get_sectors());

	// serial number
	strcpy(serial_number, "                    ");
	i = strlen(SEL_DISK(index)->get_serial());
	i = (i > 20) ? 20 : i;
	memcpy(serial_number, SEL_DISK(index)->get_serial(), i);
	for (i = 0; i < 10; i++)
		CONTROLLER(index).data[10 + i] =
		(
			serial_number[i * 2] <<
			8
			) |
		serial_number[i * 2 + 1];

	// firmware revision
	strcpy(rev_number, "        ");
	i = strlen(SEL_DISK(index)->get_rev());
	i = (i > 8) ? 8 : i;
	memcpy(rev_number, SEL_DISK(index)->get_rev(), i);
	for (i = 0; i < 4; i++)
		CONTROLLER(index).data[23 + i] =
		(
			rev_number[i * 2] <<
			8
			) |
		rev_number[i * 2 + 1];

	// model number
	strcpy(model_number, "                                        ");
	i = strlen(SEL_DISK(index)->get_model());
	i = (i > 40) ? 40 : i;
	memcpy(model_number, SEL_DISK(index)->get_model(), i);
	for (i = 0; i < 20; i++)
		CONTROLLER(index).data[i + 27] =
		(
			model_number[i * 2] <<
			8
			) |
		model_number[i * 2 + 1];

	// read/write multiple (15-8 = 0x80, 7-0 = # sectors)
	CONTROLLER(index).data[47] = 0x8000 | MAX_MULTIPLE_SECTORS;

	// capabilities
	if (!packet)
	{
		CONTROLLER(index).data[49] = 0x0300;
	}
	else
	{
		CONTROLLER(index).data[49] = 0x0a00;  // iordy; packet devices are PIO-only
	}

	// capabilities (2)
	CONTROLLER(index).data[50] = 0x4000;

	// pio data transfer number (bits 15-8)
	CONTROLLER(index).data[51] = 0x0300;

	// validity:  bit 2 = #88 valid, 1 = 64-70 valid, 0 = 54-58 valid
	CONTROLLER(index).data[53] = 7;

	// geometry: word 54 is the "current" CHS cylinder count.  ATA/ATAPI-4
	// caps it at 16383 just like word 1 — without the cap, a >=16384-cyl
	// disk reports e.g. 0x4000 here while word 1 reports 0x3fff and NT
	// logs "current CHS differs from default CHS".
	{
		u32 cyl = (u32)SEL_DISK(index)->get_cylinders();
		CONTROLLER(index).data[54] = (u16)(cyl > 16383 ? 16383 : cyl);
	}
	CONTROLLER(index).data[55] = (u16)(SEL_DISK(index)->get_heads());
	CONTROLLER(index).data[56] = (u16)(SEL_DISK(index)->get_sectors());
	CONTROLLER(index).data[57] = (u16)
		(SEL_DISK(index)->get_chs_size() >> 0) & 0xFFFF;
	CONTROLLER(index).data[58] = (u16)
		(SEL_DISK(index)->get_chs_size() >> 16) & 0xFFFF;

	// multiple sector setting (valid, 1 sector per interrupt)
	if (SEL_PER_DRIVE(index).multiple_size != 0)
	{
		CONTROLLER(index).data[59] = 0x0100 | SEL_PER_DRIVE(index).multiple_size;
	}
	else
	{
		CONTROLLER(index).data[59] = 0x0000;
	}

	// lba capacity
	CONTROLLER(index).data[60] = (u16)
		(SEL_DISK(index)->get_lba_size() >> 0) & 0xFFFF;
	CONTROLLER(index).data[61] = (u16)
		(SEL_DISK(index)->get_lba_size() >> 16) & 0xFFFF;

	// multiword dma capability (10-8: modes selected, 2-0, modes
	// supported)
	if (usedma && !packet)
		CONTROLLER(index).data[63] = CONTROLLER(index).dma_mode << 8 | 0x01;  // dma 0 supported
	else
		CONTROLLER(index).data[63] = CONTROLLER(index).dma_mode << 8 | 0x00;  // dma not supported

	// pio modes supported (bit 0 = mode 3, bit 1 = mode 4)
	CONTROLLER(index).data[64] = 0x0002;

	// minimum cycle times
	CONTROLLER(index).data[65] = 480;   // mode 0
	CONTROLLER(index).data[66] = 480;   // mode 0
	CONTROLLER(index).data[67] = 120;   // pio4
	CONTROLLER(index).data[68] = 120;   // pio4
	if (packet)
	{

		// packet to bus release time
		CONTROLLER(index).data[71] = 120;

		// service to bus release time
		CONTROLLER(index).data[72] = 120;
	}

	// queue depth (we don't do queing)
	CONTROLLER(index).data[75] = 0;

	// ata version supported (bits/version: 1,2,3,4)
	CONTROLLER(index).data[80] = 0x001e;

	// atapi revision supported (ata/atapi-4 T13 1153D revision 17)
	CONTROLLER(index).data[81] = 0x0017;

	// command set supported (cdrom = nop,packet,removable; disk=nop)
	CONTROLLER(index).data[82] = SEL_DISK(index)->cdrom() ? 0x4014 : 0x4000;

	// command sets supported(no additional command sets)
	CONTROLLER(index).data[83] = 0x4000;
	CONTROLLER(index).data[84] = 0x4000;

	// command sets enabled.
	CONTROLLER(index).data[85] = SEL_DISK(index)->cdrom() ? 0x4014 : 0x4000;
	CONTROLLER(index).data[86] = 0x4000;
	CONTROLLER(index).data[87] = 0x4000;

	// ultra dma modes supported (10-8: modes selected, 2-0, modes
	// supported)
	CONTROLLER(index).data[88] = 0x0000;
}

u32 CAliM1543C_ide::get_disk_lba(int index)
{
	if (SEL_REGISTERS(index).lba_mode)
	{
		return (SEL_REGISTERS(index).head_no << 24) |
			(
				SEL_REGISTERS(index).cylinder_no <<
				8
				) |
			SEL_REGISTERS(index).sector_no;
	}

	long heads = SEL_DISK(index)->get_heads();
	long sectors = SEL_DISK(index)->get_sectors();
	if (heads <= 0 || sectors <= 0 ||
		SEL_REGISTERS(index).head_no >= heads ||
		SEL_REGISTERS(index).sector_no < 1 ||
		SEL_REGISTERS(index).sector_no > sectors)
	{
		FAILURE(InvalidArgument, "Invalid CHS disk address");
	}

	return (u32)((((off_t_large)SEL_REGISTERS(index).cylinder_no * heads) +
		SEL_REGISTERS(index).head_no) * sectors +
		(SEL_REGISTERS(index).sector_no - 1));
}

void CAliM1543C_ide::advance_disk_address(int index, int sectors)
{
	if (sectors <= 0)
		return;

	if (SEL_REGISTERS(index).lba_mode)
	{
		u32 lba = get_disk_lba(index) + sectors;
		SEL_REGISTERS(index).sector_no = lba & 0xff;
		SEL_REGISTERS(index).cylinder_no = (lba >> 8) & 0xffff;
		SEL_REGISTERS(index).head_no = (lba >> 24) & 0x0f;
		return;
	}

	long heads = SEL_DISK(index)->get_heads();
	long sectors_per_track = SEL_DISK(index)->get_sectors();
	if (heads <= 0 || sectors_per_track <= 0)
	{
		FAILURE(InvalidArgument, "Invalid CHS disk geometry");
	}

	int sector = (SEL_REGISTERS(index).sector_no - 1) + sectors;
	SEL_REGISTERS(index).sector_no = (sector % sectors_per_track) + 1;

	int head = SEL_REGISTERS(index).head_no + (sector / sectors_per_track);
	SEL_REGISTERS(index).head_no = head % heads;
	SEL_REGISTERS(index).cylinder_no += head / heads;
}

void CAliM1543C_ide::command_aborted(int index, u8 command)
{
	printf("ide%d.%d aborting on command 0x%02x \n", index,
		CONTROLLER(index).selected, command);
	SEL_STATUS(index).busy = false;
	SEL_STATUS(index).drive_ready = true;
	SEL_STATUS(index).err = true;
	SEL_STATUS(index).drq = false;
	SEL_REGISTERS(index).error |= 0x04; // command ABORTED
	CONTROLLER(index).data_ptr = 0;
	SEL_COMMAND(index).command_in_progress = false;
	UPDATE_ALT_STATUS(index);
	raise_interrupt(index);
}

CAliM1543C_ide* theIDE = 0;

void CAliM1543C_ide::ide_status(int index)
{
	printf("IDE %d.%d: [busy: %d, drdy: %d, flt: %d, drq: %d, err: %d]\n"
		"         [c: %d, h: %d, s: %d, #: %d, f: %x, lba: %d]\n"
		"         [ptr: %d, size: %d, error: %d, cmd: %x, in progress: %d]\n"
		"         [cycle: %d, pkt phase: %d, pkt cmd: %x, dma: %d]\n"
		"         [bm-cmd: %x  bm-stat: %x]\n", index,
		CONTROLLER(index).selected, SEL_STATUS(index).busy,
		SEL_STATUS(index).drive_ready, SEL_STATUS(index).fault,
		SEL_STATUS(index).drq, SEL_STATUS(index).err,
		SEL_REGISTERS(index).cylinder_no, SEL_REGISTERS(index).head_no,
		SEL_REGISTERS(index).sector_no, SEL_REGISTERS(index).sector_count,
		SEL_REGISTERS(index).features, (SEL_REGISTERS(index).head_no << 24) | (
			SEL_REGISTERS(index).cylinder_no << 8) |
		SEL_REGISTERS(index).sector_no, CONTROLLER(index).data_ptr,
		CONTROLLER(index).data_size, SEL_REGISTERS(index).error,
		SEL_COMMAND(index).current_command & 0xff,
		SEL_COMMAND(index).command_in_progress,
		SEL_COMMAND(index).command_cycle, SEL_COMMAND(index).packet_phase,
		SEL_COMMAND(index).packet_command[0], SEL_COMMAND(index).packet_dma,
		CONTROLLER(index).busmaster[0], CONTROLLER(index).busmaster[2]);
}

/**
 * Check if threads are still running.
 **/
void CAliM1543C_ide::check_state()
{
	if (thrController[0] && !thrController[0]->isRunning())
		FAILURE(Thread, "IDE 0 thread has died");
	if (thrController[1] && !thrController[1]->isRunning())
		FAILURE(Thread, "IDE 1 thread has died");
}

void CAliM1543C_ide::execute(int index)
{
	if (SEL_DISK(index) == NULL && SEL_COMMAND(index).current_command != 0x90)
	{
		// Command issued to a nonexistent device.  Clear BSY/DRQ that
		// REG_COMMAND_COMMAND set so the host's next status read returns
		// 0xff (via get_status()'s absent-drive path).
		SEL_STATUS(index).busy = false;
		SEL_STATUS(index).drq = false;
		SEL_COMMAND(index).command_in_progress = false;
	}
	else
	{
#ifdef DEBUG_IDE_COMMAND
		printf("%%IDE-I-COMMAND: Processing command on controller %d.\n", index);
		ide_status(index);
#endif
		switch (SEL_COMMAND(index).current_command)
		{
		case 0x00:  // nop
			SEL_REGISTERS(index).error = 0x04;
			SEL_STATUS(index).busy = false;
			SEL_STATUS(index).drive_ready = true;
			SEL_STATUS(index).fault = true;
			SEL_STATUS(index).drq = false;
			SEL_STATUS(index).err = true;
			SEL_COMMAND(index).command_in_progress = false;
			raise_interrupt(index);
			printf("got nop on %d.%d\n", index, CONTROLLER(index).selected);

			// FAILURE("This isn't possible, but you're seeing it.");
			break;

		case 0x08:  // device reset
			if (SEL_DISK(index)->cdrom() || 1)
			{

				// the spec says that non-packet devices must not respond
				// to device reset.  However, by allowing it, Tru64
				// recognizes the device properly.
				SEL_COMMAND(index).command_in_progress = false;
				if (CONTROLLER(index).selected == 0)
				{
					REGISTERS(index, 0).error = 0x01;       // device passed.
					REGISTERS(index, 1).error = 0x01;       // slave not present or passed
				}
				else
				{
					REGISTERS(index, 1).error = 0x01;       // slave passed
				}

				set_signature(index, CONTROLLER(index).selected);

				// step "k", page 216 (232)
				SEL_STATUS(index).drq = false;            // bit 3
				SEL_STATUS(index).bit_2 = false;          // bit 2
				SEL_STATUS(index).err = false;            // bit 0
				if (SEL_DISK(index)->cdrom())
				{
					SEL_STATUS(index).fault = false;        // bit 5
					SEL_STATUS(index).drive_ready = false;  // per step "m2"
				}
				else
				{
					SEL_STATUS(index).drive_ready = true;   // step "m1"
				}

				SEL_STATUS(index).busy = false;

				// some sources say there's no reset on device reset.
				// raise_interrupt(index);
			}
			else
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			break;

		case 0x10:  // calibrate drive
			SEL_STATUS(index).busy = false;
			SEL_STATUS(index).drive_ready = true;
			SEL_STATUS(index).seek_complete = true;
			SEL_STATUS(index).fault = false;
			SEL_STATUS(index).drq = false;
			SEL_STATUS(index).err = false;
			SEL_REGISTERS(index).cylinder_no = 0;
			SEL_COMMAND(index).command_in_progress = false;
			raise_interrupt(index);
			break;

		case 0x20:  // read with retries
		case 0x21:  // read without retries
			if (SEL_COMMAND(index).command_cycle == 0)
			{

				// fixup the 0=256 case.
				if (SEL_REGISTERS(index).sector_count == 0)
					SEL_REGISTERS(index).sector_count = 256;
			}

			if (!SEL_STATUS(index).drq)
			{

				// buffer is empty, so lets fill it.
				{
					u32 lba = get_disk_lba(index);

					SEL_DISK(index)->seek_block(lba);
					SEL_DISK(index)->read_blocks(&(CONTROLLER(index).data[0]), 1);
#if defined(ES40_BIG_ENDIAN)
					for (int i = 0; i < SEL_DISK(index)->get_block_size() / sizeof(u16);
						i++)
						CONTROLLER(index).data[i] = endian_16(CONTROLLER(index).data[i]);
#endif
					SEL_STATUS(index).busy = false;
					SEL_STATUS(index).drive_ready = true;
					SEL_STATUS(index).fault = false;
					SEL_STATUS(index).drq = true;
					SEL_STATUS(index).err = false;
					CONTROLLER(index).data_ptr = 0;
					CONTROLLER(index).data_size = 256;

					// prepare for next sector
					SEL_REGISTERS(index).sector_count--;
					if (SEL_REGISTERS(index).sector_count == 0)
					{
						SEL_COMMAND(index).command_in_progress = false;
						if (SEL_DISK(index)->cdrom())
							set_signature(index, CONTROLLER(index).selected); // per 9.1
					}
					else
					{

						// set the next block to read.
						advance_disk_address(index, 1);
					}
				}

				raise_interrupt(index);
			}
			break;

		case 0x30:  // write with retries
		case 0x31:  // write without retries
			if (SEL_COMMAND(index).command_cycle == 0)
			{

				// this is our first time through
				if (SEL_DISK(index)->cdrom() || SEL_DISK(index)->ro())
				{
					printf("%%IDE-W-RO: Write attempt to read-only disk %d.%d.\n", index,
						CONTROLLER(index).selected);
					command_aborted(index, SEL_COMMAND(index).current_command);
				}
				else
				{
					SEL_STATUS(index).drq = true;
					SEL_STATUS(index).busy = false;
					CONTROLLER(index).data_size = 256;
					if (SEL_REGISTERS(index).sector_count == 0)
						SEL_REGISTERS(index).sector_count = 256;
				}
			}
			else
			{

				// now we should be getting data.
				if (!SEL_STATUS(index).drq)
				{

					// the buffer is full.  Do something with the data.
					{
						u32 lba = get_disk_lba(index);

#if defined(ES40_BIG_ENDIAN)
						{
							u16 data[IDE_BUFFER_SIZE];

							SEL_DISK(index)->seek_block(lba);
							for (int i = 0; i < SEL_DISK(index)->get_block_size() / sizeof(u16);
								i++)
								data[i] = endian_16(CONTROLLER(index).data[i]);
							SEL_DISK(index)->write_blocks(&(data[0]), 1);
						}

#else
						SEL_DISK(index)->seek_block(lba);
						SEL_DISK(index)->write_blocks(&(CONTROLLER(index).data[0]), 1);
#endif
						SEL_STATUS(index).busy = false;
						SEL_STATUS(index).drive_ready = true;
						SEL_STATUS(index).fault = false;
						SEL_STATUS(index).drq = true;
						SEL_STATUS(index).err = false;
						CONTROLLER(index).data_ptr = 0;

						// prepare for next sector
						SEL_REGISTERS(index).sector_count--;
						if (SEL_REGISTERS(index).sector_count == 0)
						{

							// we're done
							SEL_STATUS(index).drq = false;
							SEL_COMMAND(index).command_in_progress = false;
						}
						else
						{

							// set the next block to read.
							advance_disk_address(index, 1);
						}
					}

					raise_interrupt(index);
				}
			}
			break;

		case 0x40:  // read verify sectors with retries
		case 0x41:  // read verify sectors without retries
			if (SEL_DISK(index)->cdrom())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			else
			{
				if (SEL_REGISTERS(index).sector_count == 0)
					SEL_REGISTERS(index).sector_count = 256;

				u32 lba = get_disk_lba(index);
				int sectors = SEL_REGISTERS(index).sector_count;
				if ((off_t_large)lba + sectors > SEL_DISK(index)->get_lba_size())
				{
					command_aborted(index, SEL_COMMAND(index).current_command);
				}
				else
				{
					advance_disk_address(index, sectors);
					SEL_REGISTERS(index).sector_count = 0;
					SEL_STATUS(index).busy = false;
					SEL_STATUS(index).drive_ready = true;
					SEL_STATUS(index).seek_complete = true;
					SEL_STATUS(index).fault = false;
					SEL_STATUS(index).drq = false;
					SEL_STATUS(index).err = false;
					SEL_COMMAND(index).command_in_progress = false;
					raise_interrupt(index);
				}
			}
			break;

		case 0x70:  // seek
			if (SEL_DISK(index)->cdrom())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			else
			{
				SEL_STATUS(index).busy = false;
				SEL_STATUS(index).drive_ready = true;
				SEL_STATUS(index).seek_complete = true;
				SEL_STATUS(index).fault = false;
				SEL_STATUS(index).drq = false;
				SEL_STATUS(index).err = false;
				SEL_COMMAND(index).command_in_progress = false;
				raise_interrupt(index);
			}
			break;

			/*
			   * 0x90: execute device diagnostic: mandatory
			   */
		case 0x91:  // initialize device parameters
			SEL_COMMAND(index).command_in_progress = false;
			if (SEL_DISK(index)->cdrom())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			else
			{
#ifdef DEBUG_IDE
				printf("Original c: %d, h: %d, s: %d\n",
					SEL_DISK(index)->get_cylinders(), SEL_DISK(index)->get_heads(),
					SEL_DISK(index)->get_sectors());
				printf("Requested c: %d, h: %d, s: %d\n",
					SEL_REGISTERS(index).cylinder_no, SEL_REGISTERS(index).head_no + 1,
					SEL_REGISTERS(index).sector_count);
#endif
				if (SEL_DISK(index)->get_heads() == (SEL_REGISTERS(index).head_no + 1)
					&& SEL_DISK(index)->get_sectors() == SEL_REGISTERS(index).sector_count)
				{

					// use the default translation -- ok!
					SEL_STATUS(index).busy = false;
					SEL_STATUS(index).drive_ready = true;
					SEL_STATUS(index).fault = false;
					SEL_STATUS(index).drq = false;
					SEL_STATUS(index).err = false;
					raise_interrupt(index);
				}
				else
				{
#ifdef DEBUG_IDE
					PAUSE("INIT DEV PARAMS -- geometry not supported!");
#endif
					SEL_STATUS(index).busy = false;
					SEL_STATUS(index).drive_ready = true;
					SEL_STATUS(index).fault = false;
					SEL_STATUS(index).drq = false;
					SEL_STATUS(index).err = true;
					SEL_REGISTERS(index).error = 0x04;  // ABORT.
					raise_interrupt(index);
				}
			}
			break;

		case 0xa0:  // packet send
			/*
			 * The state machine and protocol used here was actually
			 * derived from ATA/ATAPI-5 (D1321R3) instead of the -4
			 * documenation.  State names were taken from that document.
			 */
			if (!SEL_DISK(index)->cdrom())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			else
			{
				if (SEL_REGISTERS(index).features & 0x02)
				{

					// overlap not supported
					PAUSE("overlapping not supported");
					command_aborted(index, SEL_COMMAND(index).current_command);
				}
				else
				{
					if (SEL_COMMAND(index).packet_phase == PACKET_NONE)
					{

						// this must be the first time through.
						if (!scsi_arbitrate(index))
							FAILURE(IllegalState, "ATAPI SCSI bus busy");
						if (!scsi_select(index, CONTROLLER(index).selected))
							FAILURE(IllegalState, "ATAPI device not responding to selection");
						SEL_REGISTERS(index).REASON = IR_CD;
						SEL_STATUS(index).busy = false;
						SEL_STATUS(index).drq = true;
						SEL_STATUS(index).DMRD = false;
						SEL_STATUS(index).SERV = false;
						CONTROLLER(index).data_ptr = 0;
						CONTROLLER(index).data_size = 6;
						SEL_COMMAND(index).packet_sense = 0;
						SEL_COMMAND(index).packet_asc = 0;
						SEL_COMMAND(index).packet_ascq = 0;
						SEL_COMMAND(index).packet_dma = false;
						SEL_COMMAND(index).packet_phase = PACKET_DP1;

						// we drop out of the thread and shut down the
						// controller. we will be awakened when the drq flag
						// is false, and the process will start in the state machine.
						break;
					}

					/*
					 * This is the Packet I/O state machine. The gist of
					 * it is this: we loop until yield==true, so we can
					 * move from state to state in the same DoClock().
					 * By the time we get here, we're in DP1 (Receive
					 * Packet) and we're waiting for an actual packet to
					 * arrive.
					 */
#ifdef DEBUG_IDE_PACKET
					printf("Entering Packet state machine %d\n", index);
					ide_status(index);
#endif

					bool  yield = false;
					do
					{
#ifdef DEBUG_IDE_PACKET
						printf("PACKET STATE: %s (%d)\n",
							packet_states[SEL_COMMAND(index).packet_phase],
							SEL_COMMAND(index).packet_phase);
#endif
						switch (SEL_COMMAND(index).packet_phase)
						{
						case PACKET_DP1:  // receive packet
							// we now have a full command packet.
							if (scsi_get_phase(index) != SCSI_PHASE_COMMAND)
								FAILURE(IllegalState, "SCSI command phase expected");

							memcpy(scsi_xfer_ptr(index, 12), CONTROLLER(index).data, 12);
							memcpy(SEL_COMMAND(index).packet_command, CONTROLLER(index).data,
								12);
							scsi_xfer_done(index);

							SEL_COMMAND(index).packet_phase = PACKET_DP2;
							SEL_COMMAND(index).packet_buffersize = SEL_REGISTERS(index).cylinder_no;
							SEL_STATUS(index).busy = true;
							break;

						case PACKET_DP2:  // prepare b
							SEL_STATUS(index).busy = true;
							SEL_STATUS(index).drq = false;

							if (SEL_COMMAND(index).command_in_progress)
							{
								switch (scsi_get_phase(index))
								{
								case SCSI_PHASE_DATA_IN:
								{
									size_t  num_bytes = scsi_expected_xfer(index);
									// ATAPI BYTE_COUNT register is 16 bits and *some* drivers
									// don't honor the spec's BYTE_COUNT==0 means 65536 convention.
									// Cap each chunk at 65534 (and to host-provided 
									// packet_buffersize if smaller, even-aligned for 16-bit PIO).  
									// If the SCSI engine has more data, scsi_xfer_done leaves us 
									// in the DATA_IN phase and DP34 below loops back to DP2 for the
									// next chunk.
									size_t  chunk_max = SEL_COMMAND(index).packet_buffersize;
									if (chunk_max == 0 || chunk_max > 65534)
										chunk_max = 65534;
									chunk_max &= ~(size_t)1;
									if (num_bytes > chunk_max)
										num_bytes = chunk_max;
									void* data_ptr = scsi_xfer_ptr(index, num_bytes);
									memcpy(CONTROLLER(index).data, data_ptr, num_bytes);
									scsi_xfer_done(index);
									SEL_COMMAND(index).packet_phase = PACKET_DP34;
									SEL_REGISTERS(index).BYTE_COUNT = (int)num_bytes;
									CONTROLLER(index).data_size = (int)num_bytes / 2;  // word count.
									CONTROLLER(index).data_ptr = 0;
								}
								break;

								case SCSI_PHASE_DATA_OUT:
								{
									size_t num_bytes = scsi_expected_xfer(index);
									if (SEL_COMMAND(index).packet_dma)
									{
										void* data_ptr = scsi_xfer_ptr(index, num_bytes);
										do_dma_transfer(index, (u8*)data_ptr, (u32)num_bytes, true);
										scsi_xfer_done(index);
									}
									else
									{
										SEL_COMMAND(index).packet_phase = PACKET_DP34;
										SEL_REGISTERS(index).BYTE_COUNT = (int)num_bytes;
										CONTROLLER(index).data_size = ((int)num_bytes + 1) / 2;  // word count
										CONTROLLER(index).data_ptr = 0;
										SEL_STATUS(index).busy = false;
										SEL_STATUS(index).drq = true;
										SEL_REGISTERS(index).REASON = 0; // data transfer from host to device
										raise_interrupt(index);
										yield = true;
									}
								}
								break;

								case SCSI_PHASE_STATUS:
								{
									size_t num_bytes = scsi_expected_xfer(index);
									if (num_bytes)
									{
										void* status_ptr = scsi_xfer_ptr(index, num_bytes);
										SEL_COMMAND(index).packet_sense = ((u8*)status_ptr)[0];
									}
									scsi_xfer_done(index);
									if (scsi_get_phase(index) != SCSI_PHASE_FREE)
										FAILURE(IllegalState, "SCSI bus free phase expected");
									SEL_COMMAND(index).packet_phase = PACKET_DI;
								}
								break;

								default:
									FAILURE(IllegalState, "Unexpected SCSI phase");
								}
							}
							else
							{

								// transition to an idle state
#if defined(DEBUG_IDE_PACKET)
								printf("Transition into idle state from DP2.\n");
#endif
								SEL_COMMAND(index).packet_phase = PACKET_DI;
							}
							break;

						case PACKET_DP34:
							if (scsi_get_phase(index) == SCSI_PHASE_DATA_OUT)
							{
								size_t num_bytes = scsi_expected_xfer(index);
								void* data_ptr = scsi_xfer_ptr(index, num_bytes);
								memcpy(data_ptr, CONTROLLER(index).data, num_bytes);
								scsi_xfer_done(index);
								SEL_COMMAND(index).packet_phase = PACKET_DP2;
								yield = false;
								break;
							}

							if (SEL_COMMAND(index).packet_dma)
							{

								// send back via dma
#ifdef DEBUG_IDE_PACKET
								printf("Sending ATAPI data back via DMA.\n");
#endif

								u8  status = do_dma_transfer(index,
									(u8*)(&CONTROLLER(index).data[0]),
									SEL_REGISTERS(index).BYTE_COUNT,
									false);
								if (scsi_get_phase(index) != SCSI_PHASE_STATUS)
									FAILURE(IllegalState, "SCSI status phase expected");
								{
									size_t num_bytes = scsi_expected_xfer(index);
									if (num_bytes)
									{
										void* status_ptr = scsi_xfer_ptr(index, num_bytes);
										SEL_COMMAND(index).packet_sense = ((u8*)status_ptr)[0];
									}
								}
								scsi_xfer_done(index);
								if (scsi_get_phase(index) != SCSI_PHASE_FREE)
									FAILURE(IllegalState, "SCSI bus free phase expected");
								SEL_STATUS(index).drq = true;
								SEL_STATUS(index).busy = false;
								SEL_COMMAND(index).packet_phase = PACKET_DI;
							}
							else
							{

								// send back via pio
#ifdef DEBUG_IDE_PACKET
								printf("Sending ATAPI data back via PIO.\n");
#endif
#if 0
								if ((!SEL_STATUS(index).drq) && (CONTROLLER(index).data_ptr == 0))
								{

									// first time through: no data
									// transferred, and drq=0
									SEL_STATUS(index).drq = true;
									SEL_STATUS(index).busy = false;
									SEL_REGISTERS(index).REASON = IR_IO;
									raise_interrupt(index);
									yield = true;
								}
								else
								{
									if (!SEL_STATUS(index).drq)
									{
										// all of the data has been read
										// from the buffer.
										// for now I assume that it is
										// everything.
										if (scsi_get_phase(index) != SCSI_PHASE_STATUS)
											FAILURE(IllegalState, "SCSI status phase expected");
										scsi_xfer_ptr(index, scsi_expected_xfer(index));
										scsi_xfer_done(index);
										if (scsi_get_phase(index) != SCSI_PHASE_FREE)
											FAILURE(IllegalState, "SCSI bus free phase expected");
#ifdef DEBUG_IDE_PACKET
										printf("Finished transferring!\n");
#endif
										SEL_COMMAND(index).packet_phase = PACKET_DI;
										yield = false;
									}
								}

#else

								// PIO data-in delivery, chunked.
								// First entry from DP2 (data_ptr==0, !DRQ): publish the
								// chunk -- DRQ=1, REASON=I/O, raise IRQ, yield.  Host
								// reads STATUS/BYTE_COUNT then drains the buffer.
								// Re-entry (host has drained): if SCSI still in DATA_IN,
								// loop back to DP2 for the next chunk.  Otherwise pick
								// up the SCSI status byte and let DI raise the final
								// command-complete IRQ.
								if (CONTROLLER(index).data_ptr == 0 && !SEL_STATUS(index).drq)
								{
#ifdef DEBUG_IDE_PACKET
									printf("Sending ATAPI PIO chunk (%d bytes).\n",
										SEL_REGISTERS(index).BYTE_COUNT);
#endif
									SEL_STATUS(index).drq = true;
									SEL_STATUS(index).busy = false;
									SEL_REGISTERS(index).REASON = IR_IO;
									raise_interrupt(index);
									yield = true;
									break;
								}

								if (scsi_get_phase(index) == SCSI_PHASE_DATA_IN)
								{
#ifdef DEBUG_IDE_PACKET
									printf("PIO chunk drained, fetching next.\n");
#endif
									SEL_COMMAND(index).packet_phase = PACKET_DP2;
									yield = false;
									break;
								}

								if (scsi_get_phase(index) != SCSI_PHASE_STATUS)
									FAILURE(IllegalState, "SCSI status phase expected");
								{
									size_t num_bytes = scsi_expected_xfer(index);
									if (num_bytes)
									{
										void* status_ptr = scsi_xfer_ptr(index, num_bytes);
										SEL_COMMAND(index).packet_sense = ((u8*)status_ptr)[0];
									}
								}
								scsi_xfer_done(index);
								if (scsi_get_phase(index) != SCSI_PHASE_FREE)
									FAILURE(IllegalState, "SCSI Bus free phase expected");
#ifdef DEBUG_IDE_PACKET
								printf("Finished Transferring\n");
#endif
								SEL_COMMAND(index).packet_phase = PACKET_DI;
								yield = false;
#endif
							}
							break;

						case PACKET_DI:

							// this is either DI0 or DI1
							SEL_REGISTERS(index).REASON = IR_CD | IR_IO;
							SEL_STATUS(index).busy = false;
							SEL_STATUS(index).drive_ready = true;
							SEL_STATUS(index).SERV = false;
							SEL_STATUS(index).CHK = (SEL_COMMAND(index).packet_sense != 0);
							SEL_STATUS(index).err = SEL_STATUS(index).CHK;
							if (SEL_STATUS(index).CHK)
							{
								SEL_REGISTERS(index).error = SEL_COMMAND(index).packet_sense;
								printf("%%IDE-W-ATAPI: controller %d device %d packet command",
									index, CONTROLLER(index).selected);
								for (int i = 0; i < 12; i++)
									printf(" %02x", SEL_COMMAND(index).packet_command[i]);
								printf(" returned SCSI status %02x\n",
									SEL_COMMAND(index).packet_sense);
							}
							else
							{
								SEL_REGISTERS(index).error = 0;
							}
							SEL_STATUS(index).drq = false;
							raise_interrupt(index);
							SEL_COMMAND(index).command_in_progress = false;
							yield = true;
							break;

						default:
							FAILURE(InvalidArgument, "Unknown packet phase");
						}
					} while (!yield);
#ifdef DEBUG_IDE_PACKET
					printf("Drop out of packet state machine %d\n", index);
					ide_status(index);
#endif
				}
			}
			break;

		case 0xa1:  // identify packet device
			if (SEL_DISK(index)->cdrom())
			{
				identify_drive(index, true);
				SEL_STATUS(index).busy = false;
				SEL_STATUS(index).drive_ready = true;
				SEL_STATUS(index).seek_complete = true;
				SEL_STATUS(index).fault = false;
				SEL_STATUS(index).drq = true;
				SEL_STATUS(index).err = false;
				SEL_COMMAND(index).command_in_progress = false;
				raise_interrupt(index);
			}
			else
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			break;

		case 0xc4:  // read multiple
			if (SEL_DISK(index)->cdrom())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			else
			{
				if (SEL_COMMAND(index).command_cycle == 0)
				{

					// fixup the 0=256 case.
					if (SEL_REGISTERS(index).sector_count == 0)
						SEL_REGISTERS(index).sector_count = 256;
					SEL_STATUS(index).drq = false;
				}

				if (!SEL_STATUS(index).drq)
				{

					// buffer is empty, so lets fill it.
					{
						u32 lba = get_disk_lba(index);

						if (SEL_REGISTERS(index).sector_count >= SEL_PER_DRIVE(index
						).multiple_size)
						{

							// easy, its a full block
							CONTROLLER(index).data_size = 256 * SEL_PER_DRIVE(index).multiple_size;
							SEL_REGISTERS(index).sector_count -= SEL_PER_DRIVE(index).multiple_size;
						}
						else
						{

							// partial block.
							CONTROLLER(index).data_size = 256 * SEL_REGISTERS(index).sector_count;
							SEL_REGISTERS(index).sector_count = 0;
						}

						int sectors_read = CONTROLLER(index).data_size / 256;

#ifdef DEBUG_IDE_MULTIPLE
						printf("IDE %d.%d: Reading %d sectors, %d sectors left.\n", index,
							CONTROLLER(index).selected, CONTROLLER(index).data_size / 256,
							SEL_REGISTERS(index).sector_count);
#endif
						SEL_DISK(index)->seek_block(lba);
						SEL_DISK(index)->read_blocks(&(CONTROLLER(index).data[0]),
							CONTROLLER(index).data_size / 256);  // actual number of blocks we want.
#if defined(ES40_BIG_ENDIAN)
						for (int i = 0; i < CONTROLLER(index).data_size; i++)
							CONTROLLER(index).data[i] = endian_16(CONTROLLER(index).data[i]);
#endif
						SEL_STATUS(index).busy = false;
						SEL_STATUS(index).drive_ready = true;
						SEL_STATUS(index).fault = false;
						SEL_STATUS(index).drq = true;
						SEL_STATUS(index).err = false;
						CONTROLLER(index).data_ptr = 0;

						// prepare for next sector
						if (SEL_REGISTERS(index).sector_count == 0)
						{
							SEL_COMMAND(index).command_in_progress = false;
							if (SEL_DISK(index)->cdrom())
								set_signature(index, CONTROLLER(index).selected); // per 9.1
						}
						else
						{

							// set the next block to read.
							advance_disk_address(index, sectors_read);
						}
					}

					raise_interrupt(index);
				}
			}
			break;

		case 0xc5:  // write multiple
			if (SEL_DISK(index)->cdrom())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			else
			{
				if (SEL_COMMAND(index).command_cycle == 0)
				{

					// this is our first time through
					if (SEL_DISK(index)->ro())
					{
						printf("%%IDE-W-RO: Write attempt to read-only disk %d.%d.\n",
							index, CONTROLLER(index).selected);
						command_aborted(index, SEL_COMMAND(index).current_command);
					}
					else
					{
						SEL_STATUS(index).drq = true;
						SEL_STATUS(index).busy = false;
						if (SEL_REGISTERS(index).sector_count == 0)
							SEL_REGISTERS(index).sector_count = 256;
						if (SEL_REGISTERS(index).sector_count >= SEL_PER_DRIVE(index
						).multiple_size)
						{
							CONTROLLER(index).data_size = 256 * SEL_PER_DRIVE(index).multiple_size;
							SEL_REGISTERS(index).sector_count -= SEL_PER_DRIVE(index).multiple_size;
						}
						else
						{
							CONTROLLER(index).data_size = 256 * SEL_REGISTERS(index).sector_count;
							SEL_REGISTERS(index).sector_count = 0;
						}
					}
				}
				else
				{

					// now we should be getting data.
					if (!SEL_STATUS(index).drq)
					{

						// the buffer is full.  Do something with the data.
						{
							u32 lba = get_disk_lba(index);
							int sectors_written = CONTROLLER(index).data_size / 256;

#if defined(ES40_BIG_ENDIAN)
							{
								u16 data[IDE_BUFFER_SIZE];

								SEL_DISK(index)->seek_block(lba);
								for (int i = 0; i < CONTROLLER(index).data_size; i++)
									data[i] = endian_16(CONTROLLER(index).data[i]);
								SEL_DISK(index)->write_blocks(&(data[0]),
									CONTROLLER(index).data_size / 256);
							}

#else
							SEL_DISK(index)->seek_block(lba);
							SEL_DISK(index)->write_blocks(&(CONTROLLER(index).data[0]),
								CONTROLLER(index).data_size / 256);
#endif
							SEL_STATUS(index).busy = false;
							SEL_STATUS(index).drive_ready = true;
							SEL_STATUS(index).fault = false;
							SEL_STATUS(index).drq = true;
							SEL_STATUS(index).err = false;
							CONTROLLER(index).data_ptr = 0;

							if (SEL_REGISTERS(index).sector_count == 0)
							{

								// we're done
								SEL_STATUS(index).drq = false;
								SEL_COMMAND(index).command_in_progress = false;
							}
							else
							{

								advance_disk_address(index, sectors_written);

								// prepare for next block
								if (SEL_REGISTERS(index).sector_count >= SEL_PER_DRIVE(index
								).multiple_size)
								{
									CONTROLLER(index).data_size = 256 * SEL_PER_DRIVE(index).multiple_size;
									SEL_REGISTERS(index).sector_count -= SEL_PER_DRIVE(index).multiple_size;
								}
								else
								{
									CONTROLLER(index).data_size = 256 * SEL_REGISTERS(index).sector_count;
									SEL_REGISTERS(index).sector_count = 0;
								}
							}
						}

						raise_interrupt(index);
					}
				}
			}
			break;

		case 0xc6:  // set multiple mode
			if (SEL_DISK(index)->cdrom())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
			}
			else
			{
				SEL_PER_DRIVE(index).multiple_size = SEL_REGISTERS(index).sector_count;
				printf("Set multiple mode: sector_count = %d\n",
					SEL_REGISTERS(index).sector_count);
				SEL_STATUS(index).busy = false;
				SEL_STATUS(index).drive_ready = true;
				SEL_STATUS(index).fault = false;
				SEL_STATUS(index).drq = false;
				SEL_STATUS(index).err = false;
				SEL_COMMAND(index).command_in_progress = false;
				raise_interrupt(index);
			}
			break;

		case 0xc8:  // read dma
		case 0xc9:  // read dma (old)
			if (SEL_DISK(index)->cdrom())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
				SEL_COMMAND(index).command_in_progress = false;
			}
			else
			{
				if (SEL_REGISTERS(index).sector_count == 0)
					SEL_REGISTERS(index).sector_count = 256;

#ifdef DEBUG_IDE_DMA
				printf("%%IDE-I-DMA: Read %d sectors = %d bytes.\n",
					SEL_REGISTERS(index).sector_count,
					SEL_REGISTERS(index).sector_count * 512);
#endif

				u32 lba = get_disk_lba(index);

				SEL_DISK(index)->seek_block(lba);

				SEL_DISK(index)->read_blocks(&(CONTROLLER(index).data[0]),
					SEL_REGISTERS(index).sector_count);

				u8* ptr = (u8*)(&CONTROLLER(index).data[0]);
				u8    status = do_dma_transfer(index, ptr,
					SEL_REGISTERS(index).sector_count * 512,
					false);
				SEL_COMMAND(index).command_in_progress = false;
				SEL_STATUS(index).drive_ready = true;
				SEL_STATUS(index).seek_complete = true;
				SEL_STATUS(index).fault = false;
				SEL_STATUS(index).drq = false;
				SEL_STATUS(index).err = false;
				SEL_STATUS(index).busy = false;
			}
			break;

		case 0xca:  // write dma
		case 0xcb:  // write dma (old)
			if (SEL_DISK(index)->cdrom() || SEL_DISK(index)->ro())
			{
				command_aborted(index, SEL_COMMAND(index).current_command);
				SEL_COMMAND(index).command_in_progress = false;
			}
			else
			{
				if (SEL_DISK(index)->ro())
				{
					printf("%%IDE-W-RO: DMA Write attempt to read-only disk %d.%d.\n",
						index, CONTROLLER(index).selected);
					command_aborted(index, SEL_COMMAND(index).current_command);
				}
				else
				{
					if (SEL_REGISTERS(index).sector_count == 0)
						SEL_REGISTERS(index).sector_count = 256;

#ifdef DEBUG_IDE_DMA
					printf("%%IDE-I-DMA: Write %d sectors = %d bytes.\n",
						SEL_REGISTERS(index).sector_count,
						SEL_REGISTERS(index).sector_count * 512);
#endif

					u8* ptr = (u8*)(&CONTROLLER(index).data[0]);
					u8    status = do_dma_transfer(index, ptr,
						SEL_REGISTERS(index).sector_count * 512,
						true);
					u32   lba = get_disk_lba(index);

					SEL_DISK(index)->seek_block(lba);
					SEL_DISK(index)->write_blocks(&(CONTROLLER(index).data[0]),
						SEL_REGISTERS(index).sector_count);
					SEL_COMMAND(index).command_in_progress = false;
					SEL_STATUS(index).drive_ready = true;
					SEL_STATUS(index).seek_complete = true;
					SEL_STATUS(index).fault = false;
					SEL_STATUS(index).drq = false;
					SEL_STATUS(index).err = false;
					SEL_STATUS(index).busy = false;
				}
			}
			break;

#if 0

		case 0xe5:  // check power mode
			ide_status(index);
			command_aborted(index, SEL_COMMAND(index).current_command);
			SEL_COMMAND(index).command_in_progress = false;

			// raise_interrupt(index);
			break;
#endif

		case 0xec:  // identify
			if (!SEL_DISK(index)->cdrom())
			{
				identify_drive(index, false);
				SEL_STATUS(index).busy = false;
				SEL_STATUS(index).drive_ready = true;
				SEL_STATUS(index).seek_complete = true;
				SEL_STATUS(index).fault = false;
				SEL_STATUS(index).drq = true;
				SEL_STATUS(index).err = false;
				SEL_COMMAND(index).command_in_progress = false;
				raise_interrupt(index);
			}
			else
			{
				set_signature(index, CONTROLLER(index).selected); // per

				//
				// 9.1
				command_aborted(index, 0xec);
			}
			break;

		case 0xef:    // set features
			SEL_COMMAND(index).command_in_progress = false;
			switch (SEL_REGISTERS(index).features)
			{
			case 0x03:  // set transfer mode
				if (SEL_REGISTERS(index).sector_count < 16)
				{

					// allow all PIO modes.
					SEL_STATUS(index).busy = false;
					SEL_STATUS(index).drive_ready = true;
					SEL_STATUS(index).seek_complete = true;
					SEL_STATUS(index).fault = false;
					SEL_STATUS(index).drq = false;
					SEL_STATUS(index).err = false;
					raise_interrupt(index);
					break;
				}
				else
				{

					// a DMA mode.
					switch (SEL_REGISTERS(index).sector_count)
					{
					case 0x20:
					case 0x21:
					case 0x22:

						// multiword dma
						CONTROLLER(index).dma_mode = SEL_REGISTERS(index).sector_count & 0x03;
						SEL_STATUS(index).busy = false;
						SEL_STATUS(index).drive_ready = true;
						SEL_STATUS(index).seek_complete = true;
						SEL_STATUS(index).fault = false;
						SEL_STATUS(index).drq = false;
						SEL_STATUS(index).err = false;
						raise_interrupt(index);
						break;

					case 0x40:
					case 0x41:
					case 0x42:

						// ultra dma
						command_aborted(index, SEL_COMMAND(index).current_command);
						break;
					}
					break;
				}

			default:
				printf("%%IDE-I-FEAT: Unhandled set feature subcommand %x\n",
					SEL_REGISTERS(index).features);
				command_aborted(index, SEL_COMMAND(index).current_command);
				break;
			}
			break;

			/***
				   * Special cases:  commands we don't support, but return success.
				   ***/
		case 0xde:    // door lock on removable drives
		case 0xdf:    // door unlock on removable drives
		case 0xe0:    // standby now
		case 0xe1:    // idle immediate
		case 0xe2:    // standby
		case 0xe3:    // idle
		case 0xe5:    // check power mode
		case 0xe6:    // sleep
		case 0xe7:    // flush cache
		case 0xea:    // flush cache ext
			SEL_STATUS(index).busy = false;
			SEL_STATUS(index).drive_ready = true;
			SEL_STATUS(index).drq = false;
			SEL_STATUS(index).err = false;
			SEL_COMMAND(index).command_in_progress = false;
			raise_interrupt(index);
			break;

		default:      // unknown/unhandled ATA command
			ide_status(index);
			FAILURE_1(NotImplemented, "Unknown IDE command %x",
				SEL_COMMAND(index).current_command);
			break;
		}

#ifdef DEBUG_IDE_COMMAND
		if (SEL_COMMAND(index).command_in_progress == false)
		{
			printf("%%IDE-I-COMMAND: Command has completed on controller %d.\n", index);
			ide_status(index);
			printf("==================================================\n");
		}
		else
		{
			printf("%%IDE-I-COMMAND: controller %d is yielding to host.\n", index);
			ide_status(index);
			printf("--------------------------------------------------\n");
		}
#endif
	}

	SEL_COMMAND(index).command_cycle++;
}

int CAliM1543C_ide::do_dma_transfer(int index, u8* buffer, u32 buffersize,
	bool direction)
{
	u8      xfer;
	size_t  xfersize = 0;
	u8      status = 0;
	u8      count = 0;
	u32     prd;
	semBusMaster[index]->wait();  // wait until the start bit is set.
	{
		SCOPED_READ_LOCK(mtBusMaster[index]);
		prd = endian_32(*(u32*)(&CONTROLLER(index).busmaster[4]));
	}
	do
	{
		u32 base;
		do_pci_read(prd, &base, 4, 1);

		u16 size_16;
		do_pci_read(prd + 4, &size_16, 2, 1);

		size_t  size = size_16 ? size_16 : 65536;
		do_pci_read(prd + 7, &xfer, 1, 1);

#ifdef DEBUG_IDE_DMA
		printf("-IDE-I-DMA: Transfer %d bytes to/from %lx (%x)\n", size, base, xfer);
#endif
		if (xfersize + size > buffersize)
		{

			// only copy as much data as we have from the disk.
			size = buffersize - xfersize;
			status = 2;
#ifdef DEBUG_IDE_DMA
			printf("-IDE-I-DMA: Actual transfer size: %d bytes\n", size);
#endif
		}

		// copy it to/from ram.
		if (!direction)
		{
			do_pci_write(base, buffer, 1, size);
			buffer += size;
		}
		else
		{
			do_pci_read(base, buffer, 1, size);
			buffer += size;
		}

		xfersize += size;
		prd += 8; // go to next entry.
		if (xfer == 0x80 && xfersize < buffersize)
		{

			// we still have disk data left over!
			status = 1;
		}

		if (count++ > 32)
		{
			FAILURE(InvalidArgument, "Too many PRD nodes?");
		}

		if (buffersize == xfersize && xfer != 0x80)
		{

			// we're done, but there's more prd nodes.
			status = 2;
		}
	} while (xfer != 0x80 && status == 0);

	switch (status)
	{
	case 0:     // normal completion.
	{
		SCOPED_WRITE_LOCK(mtBusMaster[index]);
		CONTROLLER(index).busmaster[2] &= 0xfe; // clear active.
	}

	raise_interrupt(index);
	break;

	case 1: // PRD is smaller than the data we have.
	{
		SCOPED_WRITE_LOCK(mtBusMaster[index]);
		CONTROLLER(index).busmaster[2] &= 0xfe; // clear active.
	}

	// do not raise an interrupt
	break;

	case 2: // PRD is larger than the data we have.
		// leave active set.
		raise_interrupt(index);
		break;
	}

	return status;
}

/**
 * Thread entry point.
 **/
void CAliM1543C_ide::run()
{
	int index = (thrController[0] == CThread::current()) ? 0 : 1;
	try
	{
		for (;;)
		{
			semController[index]->wait();
			if (StopThread)
				return;
			{
#ifdef DEBUG_IDE_THREADS
				printf("Thread %d: \n", index);
				ide_status(index);
#endif
				if (SEL_COMMAND(index).command_in_progress)
					execute(index);
				UPDATE_ALT_STATUS(index);

#ifdef IDE_YIELD_INTERRUPTS
				if (CONTROLLER(index).interrupt_pending) {
					{
						SCOPED_WRITE_LOCK(mtBusMaster[index]);
						if (CONTROLLER(index).busmaster[0] & 0x01)
							CONTROLLER(index).busmaster[2] |= 0x04;
					}
					if (channel_is_native(index))
						do_pci_interrupt(0, true);
					else
						theAli->pic_interrupt(1, 6 + index);
				}
#endif

			}
		}
	}

	catch (CException& e)
	{
		printf("Exception in IDE thread: %s.\n", e.displayText().c_str());

		// Let the thread die...
	}
}