/**

  * $Id$

  *

  * IDE interface implementation

  *

  *

  * Note: All references to read/write are from the host's point of view.

  *

  * See: INF-8020 

  * Copyright (c) 2005 Nathan Keynes.

  *

  * 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.

  */

 #define MODULE ide_module

 #include <assert.h>

 #include <stdlib.h>

 #include "dream.h"

 #include "mem.h"

 #include "asic.h"

 #include "gdrom/ide.h"

 #include "gdrom/gddriver.h"

 #include "gdrom/packet.h"

 #define MAX_WRITE_BUF 4096

 #define MAX_SECTOR_SIZE 2352 /* Audio sector */

 #define DEFAULT_DATA_SECTORS 8

 static void ide_init( void );

 static void ide_reset( void );

 static uint32_t ide_run_slice( uint32_t nanosecs );

 static void ide_save_state( FILE *f );

 static int ide_load_state( FILE *f );

 static void ide_raise_interrupt( void );

 static void ide_clear_interrupt( void );

 static void ide_packet_command( unsigned char *data );

 static void ide_read_next_sector(void);

 struct dreamcast_module ide_module = { "IDE", ide_init, ide_reset, NULL, ide_run_slice,

         NULL, ide_save_state, ide_load_state };

 struct ide_registers idereg;

 gdrom_disc_t gdrom_disc = NULL;

 unsigned char data_buffer[MAX_SECTOR_SIZE];

 #define WRITE_BUFFER(x16) *((uint16_t *)(data_buffer + idereg.data_offset)) = x16

 #define READ_BUFFER() *((uint16_t *)(data_buffer + idereg.data_offset))

 /* 10 bytes followed by "SE      REV 6.42990316" */

 unsigned char default_gdrom_mode[GDROM_MODE_LENGTH] = 

 { 0x00, 0x00, 0x00, 0x00, 0x00, 0xb4, 0x19, 0x00, 0x00, 0x08,

         0x53, 0x45, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 

         0x52, 0x65, 0x76, 0x20, 0x36, 0x2e, 0x34, 0x32, 0x39, 0x39, 0x30, 0x33, 0x31, 0x36 };

 unsigned char gdrom_71[] = { 0x3E, 0x0F, 0x90, 0xBE,  0x1D, 0xD9, 0x89, 0x04,  0x28, 0x3A, 0x8E, 0x26,  0x5C, 0x95, 0x10, 0x5A,

         0x0A, 0x99, 0xEE, 0xFB,  0x69, 0xCE, 0xD9, 0x63,  0x00, 0xF5, 0x0A, 0xBC,  0x2C, 0x0D, 0xF8, 0xE2,

         0x05, 0x02, 0x00, 0x7C,  0x03, 0x00, 0x3D, 0x08,  0xD8, 0x8D, 0x08, 0x7A,  0x6D, 0x00, 0x35, 0x06,

         0xBA, 0x66, 0x10, 0x00,  0x91, 0x08, 0x10, 0x29,  0xD0, 0x45, 0xDA, 0x00,  0x2D, 0x05, 0x69, 0x09,

         0x00, 0x5E, 0x0F, 0x70,  0x86, 0x12, 0x6C, 0x77,  0x5A, 0xFB, 0xCD, 0x56,  0xFB, 0xF7, 0xB7, 0x00,

         0x5D, 0x07, 0x19, 0x99,  0xF2, 0xAF, 0x00, 0x63,  0x03, 0x00, 0xF0, 0x10,  0xBE, 0xD7, 0xA0, 0x63,

         0xFA, 0x84, 0xA7, 0x74,  0x94, 0xEF, 0xAD, 0xC2,  0xAC, 0x00, 0x78, 0x07,  0x9F, 0x57, 0x0B, 0x62,

         0x00, 0xFE, 0x08, 0x08,  0x5D, 0x5A, 0x6A, 0x54,  0x00, 0xE2, 0x09, 0x93,  0x7E, 0x62, 0x2A, 0x5E,

         0xDA, 0x00, 0x7E, 0x0F,  0xF0, 0x07, 0x01, 0x6D,  0x50, 0x86, 0xDD, 0x4A,  0x15, 0x54, 0xC7, 0xEC,

         0x00, 0xF2, 0x0B, 0x07,  0xF8, 0x1A, 0xB0, 0x99,  0x3B, 0xF1, 0x36, 0x00,  0x94, 0x07, 0x34, 0xE3,

         0xBC, 0x6E, 0x00, 0x34,  0x0D, 0x6F, 0xDA, 0xBD,  0xEE, 0xF7, 0xCC, 0xCE,  0x39, 0x7E, 0xE3, 0x00,

         0x14, 0x08, 0xDC, 0xD2,  0xB9, 0xF9, 0x31, 0x00,  0xB0, 0x0C, 0x10, 0xA3,  0x45, 0x12, 0xC7, 0xCD,

         0xBF, 0x05, 0x37, 0x00,  0xC4, 0x0D, 0x5F, 0xE0,  0x59, 0xBB, 0x01, 0x59,  0x03, 0xD6, 0x29, 0x9C,

         0x00, 0x01, 0x0A, 0x09,  0xAA, 0xA8, 0xA8, 0x24,  0x0B, 0x66, 0x00, 0x5C,  0x05, 0xA5, 0xCE, 0x00,

         0xC1, 0x0B, 0xB7, 0xA0,  0x6F, 0xE9, 0x2B, 0xCC,  0xB5, 0xFC, 0x00, 0x8D,  0x05, 0xF4, 0xAC, 0x00,

         0x57, 0x04, 0xB6, 0x00,  0xFC, 0x03, 0x00, 0xC3,  0x10, 0x43, 0x3B, 0xBE,  0xA2, 0x96, 0xC3, 0x65,

         0x9F, 0x9A, 0x88, 0xD5,  0x49, 0x68, 0x00, 0xDC,  0x11, 0x56, 0x23, 0x2D,  0xF9, 0xFC, 0xF5, 0x8B,

         0x1B, 0xB1, 0xB7, 0x10,  0x21, 0x1C, 0x12, 0x00,  0x0D, 0x0D, 0xEB, 0x86,  0xA2, 0x49, 0x8D, 0x8D,

         0xBE, 0xA1, 0x6D, 0x53,  0x00, 0xE1, 0x0A, 0x8E,  0x67, 0xAA, 0x16, 0x79,  0x39, 0x59, 0x00, 0x36,

         0x0B, 0x2A, 0x4E, 0xAE,  0x51, 0x4B, 0xD0, 0x66,  0x33, 0x00, 0x8A, 0x07,  0xCD, 0x6F, 0xBA, 0x92,

         0x00, 0x1A, 0x0E, 0xDF,  0x4A, 0xB3, 0x77, 0x1F,  0xA5, 0x90, 0x19, 0xFA,  0x59, 0xD7, 0x00, 0x04,

         0x0F, 0xAC, 0xCA, 0x9F,  0xA4, 0xFC, 0x6D, 0x90,  0x86, 0x9E, 0x1F, 0x44,  0x40, 0x00, 0x9F, 0x04,

         0x56, 0x00, 0x22, 0x03,  0x00, 0xB8, 0x10, 0x2C,  0x7A, 0x53, 0xA4, 0xBF,  0xA3, 0x90, 0x90, 0x14,

         0x9D, 0x46, 0x6C, 0x96,  0x00, 0xC6, 0x0B, 0x9B,  0xBB, 0xB0, 0xAE, 0x60,  0x92, 0x8E, 0x0C, 0x00,

         0x14, 0x06, 0x4B, 0xAE,  0x7F, 0x00, 0x5C, 0x0B,  0x23, 0xFA, 0xE7, 0x51,  0xDA, 0x61, 0x49, 0x5E,

         0x00, 0xD7, 0x0B, 0x01,  0xFC, 0x55, 0x31, 0x84,  0xC5, 0x0C, 0x98, 0x00,  0x97, 0x50, 0x6E, 0xF9,

         0xEE, 0x75, 0x92, 0x53,  0xD3, 0x66, 0xA4, 0xAF,  0x3B, 0xFE, 0x7B, 0x27,  0x30, 0xBB, 0xB6, 0xF2,

         0x76, 0x22, 0x45, 0x42,  0xCA, 0xF9, 0xF0, 0xDE,  0x9F, 0x45, 0x16, 0x68,  0x22, 0xB9, 0x84, 0x28,

         0x8F, 0x2B, 0xB5, 0x5C,  0xD2, 0xF5, 0x45, 0x36,  0x3E, 0x76, 0xC6, 0xBF,  0x32, 0x5C, 0x41, 0xA6,

         0x26, 0xC7, 0x82, 0x2F,  0x2E, 0xB5, 0x75, 0xC6,  0xE6, 0x67, 0x9E, 0x77,  0x94, 0xAF, 0x6A, 0x05,

         0xC0, 0x05, 0x61, 0x71,  0x89, 0x5A, 0xB1, 0xD0,  0xFC, 0x7E, 0xC0, 0x9B,  0xCB, 0x3B, 0x69, 0xD9,

         0x5F, 0xAF, 0xCA, 0xAB,  0x25, 0xD5, 0xBE, 0x8A,  0x6B, 0xB0, 0xFB, 0x61,  0x6C, 0xEB, 0x85, 0x6E,

         0x7A, 0x48, 0xFF, 0x97,  0x91, 0x06, 0x3D, 0x4D,  0x68, 0xD3, 0x65, 0x83,  0x90, 0xA0, 0x08, 0x5C,

         0xFC, 0xEE, 0x7C, 0x33,  0x43, 0x7F, 0x80, 0x52,  0x8B, 0x19, 0x72, 0xF2,  0xC9, 0xAB, 0x93, 0xAF,

         0x16, 0xED, 0x36, 0x48,  0xAB, 0xC9, 0xD1, 0x03,  0xB3, 0xDC, 0x2F, 0xF2,  0x92, 0x3F, 0x0A, 0x19,

         0x25, 0xE2, 0xEF, 0x7A,  0x22, 0xDA, 0xDB, 0xCB,  0x32, 0x12, 0x61, 0x49,  0x5B, 0x74, 0x7C, 0x65,

         0x20, 0x89, 0x54, 0x9E,  0x0E, 0xC9, 0x52, 0xE3,  0xC9, 0x9A, 0x44, 0xC9,  0x5D, 0xA6, 0x77, 0xC0,

         0xE7, 0x60, 0x91, 0x80,  0x50, 0x1F, 0x33, 0xB1,  0xCD, 0xAD, 0xF4, 0x0D,  0xBB, 0x08, 0xB1, 0xD0,

         0x13, 0x95, 0xAE, 0xC9,  0xE2, 0x64, 0xA2, 0x65,  0xFB, 0x8F, 0xE9, 0xA2,  0x8A, 0xBC, 0x98, 0x81,

         0x45, 0xB4, 0x55, 0x4E,  0xB9, 0x74, 0xB4, 0x50,  0x76, 0xBF, 0xF0, 0x45,  0xE7, 0xEE, 0x41, 0x64,

         0x9F, 0xB5, 0xE0, 0xBB,  0x1C, 0xBB, 0x28, 0x66,  0x1B, 0xDD, 0x2B, 0x02,  0x66, 0xBF, 0xFD, 0x7D,

         0x37, 0x35, 0x1D, 0x76,  0x21, 0xC3, 0x8F, 0xAF,  0xF6, 0xF9, 0xE9, 0x27,  0x48, 0xE7, 0x3D, 0x95,

         0x74, 0x0C, 0x77, 0x88,  0x56, 0xD9, 0x84, 0xC8,  0x7D, 0x20, 0x31, 0x43,  0x53, 0xF1, 0xC1, 0xC7,

         0xC9, 0xF7, 0x5C, 0xC0,  0xA6, 0x5A, 0x27, 0x0A,  0x41, 0xD4, 0x44, 0x94,  0x65, 0x4F, 0xE2, 0x53,

         0x60, 0x0B, 0xD1, 0x23,  0x6C, 0x0C, 0xBC, 0x70,  0x6C, 0x26, 0x1A, 0x61,  0x1D, 0x35, 0x88, 0xEC,

         0xB8, 0x15, 0xE3, 0xB4,  0x82, 0xEE, 0xB3, 0x21,  0xAC, 0x6C, 0xB7, 0x33,  0x6D, 0x78, 0x0C, 0x0D,

         0xB4, 0x0B, 0x29, 0xF2,  0xD4, 0x8C, 0x3F, 0xDD,  0x3F, 0x47, 0xDD, 0xF2,  0xD8, 0x39, 0x57, 0x20,

         0x28, 0xD8, 0xDD, 0x32,  0xE2, 0x6A, 0x47, 0x53,  0x57, 0xC6, 0xFA, 0x7A,  0x38, 0x30, 0x31, 0x8F,

         0xE7, 0xD3, 0x84, 0x2B,  0x5D, 0x4F, 0x95, 0x98,  0xED, 0x0B, 0xD7, 0x50,  0x0C, 0x49, 0xDA, 0x59,

         0x15, 0xF1, 0x39, 0xF3,  0x40, 0xDC, 0xDC, 0x25,  0x24, 0x56, 0x6E, 0xA9,  0x2F, 0xF0, 0x00, 0x00 };

 char gdrom_status[] = { 

         0x00, 0x15, 0x00, 0x64, 0x00, 0x40, 0x00, 0x00, 

         0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00,

         0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00,

         0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00,

         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

         0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00,

         0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

         0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x40, 0x40,

         0x40, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00,

         0x00, 0x40, 0x40, 0x00, 0x00, 0x00, 0x40, 0x40,

         0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x40, 0x00,

         0x00, 0x40, 0x00, 0x00 };

 static void ide_init( void )

 {

     ide_reset();

 }

 static void ide_reset( void )

 {

     ide_clear_interrupt();

     idereg.error = 0x01;

     idereg.count = 0x01;

     idereg.lba0 = /* 0x21; */ 0x81;

     idereg.lba1 = 0x14;

     idereg.lba2 = 0xeb;

     idereg.feature = 0; /* Indeterminate really */

     idereg.status = 0x00;

     idereg.device = 0x00;

     idereg.state = IDE_STATE_IDLE;

     memset( idereg.gdrom_sense, '\0', 10 );

     memcpy( idereg.gdrom_mode, default_gdrom_mode, GDROM_MODE_LENGTH );

     idereg.data_offset = -1;

     idereg.data_length = -1;

     idereg.last_read_track = 1;

     idereg.current_lba = 150;

     idereg.current_mode = 0x28;

     idereg.sectors_left = 0;

     idereg.was_reset = TRUE;

 }

 static uint32_t ide_run_slice( uint32_t nanosecs )

 {

     if( gdrom_disc != NULL && gdrom_disc->run_time_slice != NULL ) {

         gdrom_disc->run_time_slice(gdrom_disc, nanosecs);

     }

     return nanosecs;

 }

 static void ide_save_state( FILE *f )

 {

     fwrite( &idereg, sizeof(idereg), 1, f );

     fwrite( data_buffer, MAX_SECTOR_SIZE, 1, f );

 }

 static int ide_load_state( FILE *f )

 {

     fread( &idereg, sizeof(idereg), 1, f );

     fread( data_buffer, MAX_SECTOR_SIZE, 1, f );

     return 0;

 }

 /************************ State transitions *************************/

 void ide_set_packet_result( uint16_t result )

 {

     idereg.gdrom_sense[0] = 0xf0;

     idereg.gdrom_sense[2] = result & 0xFF;

     idereg.gdrom_sense[8] = (result >> 8) & 0xFF;

     idereg.error = (result & 0x0F) << 4;

     idereg.count = 3;

     if( result != 0 ) {

         idereg.status = 0x51;

         idereg.state = IDE_STATE_IDLE;

         ide_raise_interrupt();

     } else {

         idereg.status = idereg.status & ~(IDE_STATUS_BSY|IDE_STATUS_CHK);

     }

 }

 /**

  * Begin command packet write to the device. This is always 12 bytes of PIO data

  */

 static void ide_start_command_packet_write( )

 {

     idereg.state = IDE_STATE_CMD_WRITE;

     idereg.status = 0x58;

     idereg.error = idereg.feature & 0x03; /* Copy values of OVL/DMA */

     idereg.count = IDE_COUNT_CD;

     idereg.data_offset = 0;

     idereg.data_length = 12;

 }

 /**

  * Begin PIO/DMA read from the device. The data is assumed to already be

  * in the buffer at this point.

  */

 static void ide_start_read( int length, gboolean dma ) 

 {

     idereg.count = IDE_COUNT_IO;

     idereg.data_length = length;

     idereg.data_offset = 0;

     if( dma ) {

         idereg.state = IDE_STATE_DMA_READ;

         idereg.status = 0xD0;

     } else {

         idereg.state = IDE_STATE_PIO_READ;

         idereg.status = 0x58;

         idereg.lba1 = length & 0xFF;

         idereg.lba2 = length >> 8; 

         ide_raise_interrupt( );

     }

 }

 static void ide_start_write( int length, gboolean dma )

 {

     idereg.count = 0;

     idereg.data_length = length;

     idereg.data_offset = 0;

     if( dma ) {

         idereg.state = IDE_STATE_DMA_WRITE;

         idereg.status = 0xD0;

     }  else {

         idereg.state = IDE_STATE_PIO_WRITE;

         idereg.status = 0x58;

         idereg.lba1 = length & 0xFF;

         idereg.lba2 = length >> 8;

         ide_raise_interrupt( );

     }

 }

 static void ide_start_packet_read( int length, int sector_count )

 {

     idereg.sectors_left = sector_count;

     ide_set_packet_result( PKT_ERR_OK );

     ide_start_read( length, (idereg.feature & IDE_FEAT_DMA) ? TRUE : FALSE );

 }

 static void ide_start_packet_write( int length, int sector_count )

 {

     idereg.sectors_left = sector_count;

     ide_set_packet_result( PKT_ERR_OK );

     ide_start_write( length, (idereg.feature & IDE_FEAT_DMA) ? TRUE : FALSE );

 }

 static void ide_raise_interrupt( void )

 {

     if( idereg.intrq_pending == 0 ) {

         idereg.intrq_pending = 1;

         if( IS_IDE_IRQ_ENABLED() )

             asic_event( EVENT_IDE );

     }

 }

 static void ide_clear_interrupt( void ) 

 {

     if( idereg.intrq_pending != 0 ) {

         idereg.intrq_pending = 0;

         if( IS_IDE_IRQ_ENABLED() )

             asic_clear_event( EVENT_IDE );

     }

 }

 static void ide_set_error( int error_code )

 {

     idereg.status = 0x51;

     idereg.error = error_code;

 }

 uint8_t ide_read_status( void ) 

 {

     if( (idereg.status & IDE_STATUS_BSY) == 0 )

         ide_clear_interrupt();

     return idereg.status;

 }

 uint16_t ide_read_data_pio( void ) {

     if( idereg.state == IDE_STATE_PIO_READ ) {

         uint16_t rv = READ_BUFFER();

         idereg.data_offset += 2;

         if( idereg.data_offset >= idereg.data_length ) {

             idereg.state = IDE_STATE_IDLE;

             idereg.status &= ~IDE_STATUS_DRQ;

             idereg.data_offset = -1;

             idereg.count = 3; /* complete */

             ide_raise_interrupt();

             if( idereg.sectors_left > 0 ) {

                 ide_read_next_sector();

             }

         }

         return rv;

     } else {

         return 0xFFFF;

     }

 }

 /**

  * DMA read request

  *

  * This method is called from the ASIC side when a DMA read request is

  * initiated. If there is a pending DMA transfer already, we copy the

  * data immediately, otherwise we record the DMA buffer for use when we

  * get to actually doing the transfer.

  * @return number of bytes transfered

  */

 uint32_t ide_read_data_dma( uint32_t addr, uint32_t length )

 {

     uint32_t xfercount = 0;

     while( xfercount < length && idereg.state == IDE_STATE_DMA_READ ) {

         int xferlen = length - xfercount;

         int remaining = idereg.data_length - idereg.data_offset;

         if( xferlen > remaining ) {

             xferlen = remaining;

         }

         mem_copy_to_sh4( addr, (data_buffer + idereg.data_offset), xferlen );

         xfercount += xferlen;

         addr += xferlen;

         idereg.data_offset += xferlen;

         if( idereg.data_offset >= idereg.data_length ) {

             if( idereg.sectors_left > 0 ) {

                 ide_read_next_sector();

             } else {

                 idereg.data_offset = -1;

                 idereg.state = IDE_STATE_IDLE;

                 idereg.status = 0x50;

                 idereg.count = 0x03;

                 ide_raise_interrupt();

                 break;

             }

         }

     }

     return xfercount;

 }

 void ide_write_data_pio( uint16_t val ) {

     if( idereg.state == IDE_STATE_CMD_WRITE ) {

         WRITE_BUFFER(val);

         idereg.data_offset+=2;

         if( idereg.data_offset >= idereg.data_length ) {

             idereg.state = IDE_STATE_BUSY;

             idereg.status = (idereg.status & ~IDE_STATUS_DRQ) | IDE_STATUS_BSY;

             idereg.data_offset = -1;

             ide_packet_command(data_buffer);

         }

     } else if( idereg.state == IDE_STATE_PIO_WRITE ) {

         WRITE_BUFFER(val);

         idereg.data_offset +=2;

         if( idereg.data_offset >= idereg.data_length ) {

             idereg.state = IDE_STATE_IDLE;

             idereg.status &= ~IDE_STATUS_DRQ;

             idereg.data_offset = -1;

             idereg.count = 3; /* complete */

             ide_raise_interrupt();

             ide_write_buffer( data_buffer, idereg.data_length );

         }

     }

 }

 void ide_write_control( uint8_t val ) {

     if( IS_IDE_IRQ_ENABLED() ) {

         if( (val & 0x02) != 0 && idereg.intrq_pending != 0 )

             asic_clear_event( EVENT_IDE );

     } else {

         if( (val & 0x02) == 0 && idereg.intrq_pending != 0 )

             asic_event( EVENT_IDE );

     }

     idereg.control = val;

 }

 void ide_write_command( uint8_t val ) {

     ide_clear_interrupt();

     idereg.command = val;

     switch( val ) {

     case IDE_CMD_NOP: /* Effectively an "abort" */

         idereg.state = IDE_STATE_IDLE;

         idereg.status = 0x51;

         idereg.error = 0x04;

         idereg.data_offset = -1;

         ide_raise_interrupt();

         return;

     case IDE_CMD_RESET_DEVICE:

         ide_reset();

         break;

     case IDE_CMD_PACKET:

         ide_start_command_packet_write();

         break;

     case IDE_CMD_SET_FEATURE:

         switch( idereg.feature ) {

         case IDE_FEAT_SET_TRANSFER_MODE:

             switch( idereg.count & 0xF8 ) {

             case IDE_XFER_PIO:

                 INFO( "Set PIO default mode: %d", idereg.count&0x07 );

                 break;

             case IDE_XFER_PIO_FLOW:

                 INFO( "Set PIO Flow-control mode: %d", idereg.count&0x07 );

                 break;

             case IDE_XFER_MULTI_DMA:

                 INFO( "Set Multiword DMA mode: %d", idereg.count&0x07 );

                 break;

             case IDE_XFER_ULTRA_DMA:

                 INFO( "Set Ultra DMA mode: %d", idereg.count&0x07 );

                 break;

             default:

                 INFO( "Setting unknown transfer mode: %02X", idereg.count );

                 break;

             }

             break;

             default:

                 WARN( "IDE: unimplemented feature: %02X", idereg.feature );

         }

         idereg.status = 0x50;

         idereg.error = 0x00;

         idereg.lba1 = 0x00;

         idereg.lba2 = 0x00;

         ide_raise_interrupt();

         break;

         default:

             WARN( "IDE: Unimplemented command: %02X", val );

     }

 }

 uint8_t ide_get_drive_status( void )

 {

     if( gdrom_disc == NULL ) {

         return IDE_DISC_NONE;

     } else {

         return gdrom_disc->drive_status(gdrom_disc);

     }

 }

 #define REQUIRE_DISC() if( gdrom_disc == NULL ) { ide_set_packet_result( PKT_ERR_NODISC ); return; }

 /**

  * Read the next sector from the active read, if any

  */

 static void ide_read_next_sector( void )

 {

     uint32_t sector_size;

     REQUIRE_DISC();

     gdrom_error_t status = 

         gdrom_disc->read_sector( gdrom_disc, idereg.current_lba, idereg.current_mode, 

                 data_buffer, &sector_size );

     if( status != PKT_ERR_OK ) {

         ide_set_packet_result( status );

         idereg.gdrom_sense[5] = (idereg.current_lba >> 16) & 0xFF;

         idereg.gdrom_sense[6] = (idereg.current_lba >> 8) & 0xFF;

         idereg.gdrom_sense[7] = idereg.current_lba & 0xFF;

         WARN( " => Read CD returned sense key %02X, %02X", status & 0xFF, status >> 8 );

     } else {

         idereg.current_lba++;

         idereg.sectors_left--;

         ide_start_read( sector_size, (idereg.feature & IDE_FEAT_DMA) ? TRUE : FALSE );

     }

 }

 /**

  * Execute a packet command. This particular method is responsible for parsing

  * the command buffers (12 bytes), and generating the appropriate responses, 

  * although the actual implementation is mostly delegated to gdrom.c

  */

 void ide_packet_command( unsigned char *cmd )

 {

     uint32_t length;

     uint32_t lba, status;

     /* Okay we have the packet in the command buffer */

     INFO( "ATAPI packet: %02X %02X %02X %02X  %02X %02X %02X %02X  %02X %02X %02X %02X", 

           cmd[0], cmd[1], cmd[2], cmd[3], cmd[4], cmd[5], cmd[6], cmd[7],

           cmd[8], cmd[9], cmd[10], cmd[11] );

     if( cmd[0] != PKT_CMD_SENSE && idereg.was_reset ) {

         ide_set_packet_result( PKT_ERR_RESET );

         idereg.was_reset = FALSE;

         return;

     }

     switch( cmd[0] ) {

     case PKT_CMD_TEST_READY:

         REQUIRE_DISC();

         ide_set_packet_result( 0 );

         ide_raise_interrupt();

         idereg.status = 0x50;

         break;

     case PKT_CMD_DRIVE_STATUS:

         lba = cmd[2];

         if( lba >= GDROM_DRIVE_STATUS_LENGTH ) {

             ide_set_error(PKT_ERR_BADFIELD);

         } else {

             uint8_t status = ide_get_drive_status();

             /* FIXME: Refactor read_position to avoid this kind of crud */

             unsigned char tmp[16];

             gdrom_disc->read_position( gdrom_disc, idereg.current_lba, tmp );

             length = cmd[4];

             if( lba+length > GDROM_DRIVE_STATUS_LENGTH )

                 length = GDROM_DRIVE_STATUS_LENGTH - lba;

             char data[10];

             data[0] = status & 0x0F;

             data[1] = status & 0xF0;

             data[2] = tmp[4];

             data[3] = tmp[5];

             data[4] = tmp[6];

             data[5] = tmp[11];

             data[6] = tmp[12];

             data[7] = tmp[13];

             data[8] = 0;

             data[9] = 0;

             memcpy( data_buffer, data + lba, length );

             ide_start_packet_read( length, 0 );

         }

         break;

     case PKT_CMD_MODE_SENSE:

         lba = cmd[2];

         if( lba >= GDROM_MODE_LENGTH ) {

             ide_set_error(PKT_ERR_BADFIELD);

         } else {

             length = cmd[4];

             if( lba+length > GDROM_MODE_LENGTH )

                 length = GDROM_MODE_LENGTH - lba;

             memcpy( data_buffer, idereg.gdrom_mode + lba, length );

             ide_start_packet_read( length, 0 );

         }

         break;

     case PKT_CMD_MODE_SELECT:

         lba = cmd[2];

         if( lba >= GDROM_MODE_LENGTH ) {

             ide_set_error(PKT_ERR_BADFIELD);

         } else {

             length = cmd[4];

             if( lba+length > GDROM_MODE_LENGTH )

                 length = GDROM_MODE_LENGTH - lba;

             idereg.current_lba = lba;

             ide_start_packet_write( length, 0 );

         }

         break;

     case PKT_CMD_SENSE:

         length = cmd[4];

         if( length > 10 )

             length = 10;

         memcpy( data_buffer, idereg.gdrom_sense, length );

         ide_start_packet_read( length, 0 );

         break;

     case PKT_CMD_READ_TOC:

         REQUIRE_DISC();

         length = (cmd[3]<<8) | cmd[4];

         if( length > sizeof(struct gdrom_toc) )

             length = sizeof(struct gdrom_toc);

         status = gdrom_disc->read_toc( gdrom_disc, data_buffer );

         if( status != PKT_ERR_OK ) {

             ide_set_packet_result( status );

         } else {

             ide_start_packet_read( length, 0 );

         }

         break;

     case PKT_CMD_SESSION_INFO:

         REQUIRE_DISC();

         length = cmd[4];

         if( length > 6 )

             length = 6;

         status = gdrom_disc->read_session( gdrom_disc, cmd[2], data_buffer );

         if( status != PKT_ERR_OK ) {

             ide_set_packet_result( status );

         } else {

             ide_start_packet_read( length, 0 );

         }

         break;

     case PKT_CMD_PLAY_AUDIO:

         REQUIRE_DISC();

         ide_set_packet_result( 0 );

         ide_raise_interrupt();

         idereg.status = 0x50;

         break;

     case PKT_CMD_READ_SECTOR:

         REQUIRE_DISC();

         idereg.current_lba = cmd[2] << 16 | cmd[3] << 8 | cmd[4];

         idereg.sectors_left = cmd[8] << 16 | cmd[9] << 8 | cmd[10]; /* blocks */

         idereg.current_mode = cmd[1];

         ide_read_next_sector();

         break;

     case PKT_CMD_SPIN_UP:

         REQUIRE_DISC();

         /* do nothing? */

         ide_set_packet_result( PKT_ERR_OK );

         ide_raise_interrupt();

         break;

     case PKT_CMD_STATUS:

         REQUIRE_DISC();

         length = cmd[4];

         switch( cmd[1] ) {

         case 0:

             if( length > sizeof(gdrom_status) ) {

                 length = sizeof(gdrom_status);

             }

             memcpy( data_buffer, gdrom_status, length );

             ide_start_packet_read( length, 0 );

             break;

         case 1:

             if( length > 14 ) {

                 length = 14;

             }

             gdrom_disc->read_position( gdrom_disc, idereg.current_lba, data_buffer );

             data_buffer[0] = 0x00;

             data_buffer[1] = 0x15; /* audio status ? */

             data_buffer[2] = 0x00;

             data_buffer[3] = 0x0E;

             ide_start_packet_read( length, 0 );

             break;

         }

         break;

         case PKT_CMD_71:

             /* This is a weird one. As far as I can tell it returns random garbage

              * (and not even the same length each time, never mind the same data).

              * For sake of something to do, it returns the results from a test dump

              */

             REQUIRE_DISC();

             memcpy( data_buffer, gdrom_71, sizeof(gdrom_71) );

             ide_start_packet_read( sizeof(gdrom_71), 0 );

             break;

         default:

             ide_set_packet_result( PKT_ERR_BADCMD ); /* Invalid command */

             return;

     }

     idereg.last_packet_command = cmd[0];

 }

 void ide_write_buffer( unsigned char *data, uint32_t length )

 {

     switch( idereg.last_packet_command ) {

     case PKT_CMD_MODE_SELECT:

         if( idereg.current_lba < 10 ) {

             if( idereg.current_lba + length > 10 ) {

                 length = 10 - idereg.current_lba;

             }

             memcpy( idereg.gdrom_mode + idereg.current_lba, data, length );

         }

         break;

     default:

         WARN( "Don't know what to do with received data buffer for command %02X", idereg.last_packet_command );

     }

 }