Archipelago » qemu

/*

 * QEMU IDE disk and CD-ROM Emulator

 * 

 * Copyright (c) 2003 Fabrice Bellard

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "vl.h"

/* debug IDE devices */

//#define DEBUG_IDE

//#define DEBUG_IDE_ATAPI

/* Bits of HD_STATUS */

#define ERR_STAT                0x01

#define INDEX_STAT                0x02

#define ECC_STAT                0x04        /* Corrected error */

#define DRQ_STAT                0x08

#define SEEK_STAT                0x10

#define SRV_STAT                0x10

#define WRERR_STAT                0x20

#define READY_STAT                0x40

#define BUSY_STAT                0x80

/* Bits for HD_ERROR */

#define MARK_ERR                0x01        /* Bad address mark */

#define TRK0_ERR                0x02        /* couldn't find track 0 */

#define ABRT_ERR                0x04        /* Command aborted */

#define MCR_ERR                        0x08        /* media change request */

#define ID_ERR                        0x10        /* ID field not found */

#define MC_ERR                        0x20        /* media changed */

#define ECC_ERR                        0x40        /* Uncorrectable ECC error */

#define BBD_ERR                        0x80        /* pre-EIDE meaning:  block marked bad */

#define ICRC_ERR                0x80        /* new meaning:  CRC error during transfer */

/* Bits of HD_NSECTOR */

#define CD                        0x01

#define IO                        0x02

#define REL                        0x04

#define TAG_MASK                0xf8

#define IDE_CMD_RESET           0x04

#define IDE_CMD_DISABLE_IRQ     0x02

/* ATA/ATAPI Commands pre T13 Spec */

#define WIN_NOP                                0x00

/*

 *        0x01->0x02 Reserved

 */

#define CFA_REQ_EXT_ERROR_CODE                0x03 /* CFA Request Extended Error Code */

/*

 *        0x04->0x07 Reserved

 */

#define WIN_SRST                        0x08 /* ATAPI soft reset command */

#define WIN_DEVICE_RESET                0x08

/*

 *        0x09->0x0F Reserved

 */

#define WIN_RECAL                        0x10

#define WIN_RESTORE                        WIN_RECAL

/*

 *        0x10->0x1F Reserved

 */

#define WIN_READ                        0x20 /* 28-Bit */

#define WIN_READ_ONCE                        0x21 /* 28-Bit without retries */

#define WIN_READ_LONG                        0x22 /* 28-Bit */

#define WIN_READ_LONG_ONCE                0x23 /* 28-Bit without retries */

#define WIN_READ_EXT                        0x24 /* 48-Bit */

#define WIN_READDMA_EXT                        0x25 /* 48-Bit */

#define WIN_READDMA_QUEUED_EXT                0x26 /* 48-Bit */

#define WIN_READ_NATIVE_MAX_EXT                0x27 /* 48-Bit */

/*

 *        0x28

 */

#define WIN_MULTREAD_EXT                0x29 /* 48-Bit */

/*

 *        0x2A->0x2F Reserved

 */

#define WIN_WRITE                        0x30 /* 28-Bit */

#define WIN_WRITE_ONCE                        0x31 /* 28-Bit without retries */

#define WIN_WRITE_LONG                        0x32 /* 28-Bit */

#define WIN_WRITE_LONG_ONCE                0x33 /* 28-Bit without retries */

#define WIN_WRITE_EXT                        0x34 /* 48-Bit */

#define WIN_WRITEDMA_EXT                0x35 /* 48-Bit */

#define WIN_WRITEDMA_QUEUED_EXT                0x36 /* 48-Bit */

#define WIN_SET_MAX_EXT                        0x37 /* 48-Bit */

#define CFA_WRITE_SECT_WO_ERASE                0x38 /* CFA Write Sectors without erase */

#define WIN_MULTWRITE_EXT                0x39 /* 48-Bit */

/*

 *        0x3A->0x3B Reserved

 */

#define WIN_WRITE_VERIFY                0x3C /* 28-Bit */

/*

 *        0x3D->0x3F Reserved

 */

#define WIN_VERIFY                        0x40 /* 28-Bit - Read Verify Sectors */

#define WIN_VERIFY_ONCE                        0x41 /* 28-Bit - without retries */

#define WIN_VERIFY_EXT                        0x42 /* 48-Bit */

/*

 *        0x43->0x4F Reserved

 */

#define WIN_FORMAT                        0x50

/*

 *        0x51->0x5F Reserved

 */

#define WIN_INIT                        0x60

/*

 *        0x61->0x5F Reserved

 */

#define WIN_SEEK                        0x70 /* 0x70-0x7F Reserved */

#define CFA_TRANSLATE_SECTOR                0x87 /* CFA Translate Sector */

#define WIN_DIAGNOSE                        0x90

#define WIN_SPECIFY                        0x91 /* set drive geometry translation */

#define WIN_DOWNLOAD_MICROCODE                0x92

#define WIN_STANDBYNOW2                        0x94

#define WIN_STANDBY2                        0x96

#define WIN_SETIDLE2                        0x97

#define WIN_CHECKPOWERMODE2                0x98

#define WIN_SLEEPNOW2                        0x99

/*

 *        0x9A VENDOR

 */

#define WIN_PACKETCMD                        0xA0 /* Send a packet command. */

#define WIN_PIDENTIFY                        0xA1 /* identify ATAPI device        */

#define WIN_QUEUED_SERVICE                0xA2

#define WIN_SMART                        0xB0 /* self-monitoring and reporting */

#define CFA_ERASE_SECTORS               0xC0

#define WIN_MULTREAD                        0xC4 /* read sectors using multiple mode*/

#define WIN_MULTWRITE                        0xC5 /* write sectors using multiple mode */

#define WIN_SETMULT                        0xC6 /* enable/disable multiple mode */

#define WIN_READDMA_QUEUED                0xC7 /* read sectors using Queued DMA transfers */

#define WIN_READDMA                        0xC8 /* read sectors using DMA transfers */

#define WIN_READDMA_ONCE                0xC9 /* 28-Bit - without retries */

#define WIN_WRITEDMA                        0xCA /* write sectors using DMA transfers */

#define WIN_WRITEDMA_ONCE                0xCB /* 28-Bit - without retries */

#define WIN_WRITEDMA_QUEUED                0xCC /* write sectors using Queued DMA transfers */

#define CFA_WRITE_MULTI_WO_ERASE        0xCD /* CFA Write multiple without erase */

#define WIN_GETMEDIASTATUS                0xDA        

#define WIN_ACKMEDIACHANGE                0xDB /* ATA-1, ATA-2 vendor */

#define WIN_POSTBOOT                        0xDC

#define WIN_PREBOOT                        0xDD

#define WIN_DOORLOCK                        0xDE /* lock door on removable drives */

#define WIN_DOORUNLOCK                        0xDF /* unlock door on removable drives */

#define WIN_STANDBYNOW1                        0xE0

#define WIN_IDLEIMMEDIATE                0xE1 /* force drive to become "ready" */

#define WIN_STANDBY                     0xE2 /* Set device in Standby Mode */

#define WIN_SETIDLE1                        0xE3

#define WIN_READ_BUFFER                        0xE4 /* force read only 1 sector */

#define WIN_CHECKPOWERMODE1                0xE5

#define WIN_SLEEPNOW1                        0xE6

#define WIN_FLUSH_CACHE                        0xE7

#define WIN_WRITE_BUFFER                0xE8 /* force write only 1 sector */

#define WIN_WRITE_SAME                        0xE9 /* read ata-2 to use */

        /* SET_FEATURES 0x22 or 0xDD */

#define WIN_FLUSH_CACHE_EXT                0xEA /* 48-Bit */

#define WIN_IDENTIFY                        0xEC /* ask drive to identify itself        */

#define WIN_MEDIAEJECT                        0xED

#define WIN_IDENTIFY_DMA                0xEE /* same as WIN_IDENTIFY, but DMA */

#define WIN_SETFEATURES                        0xEF /* set special drive features */

#define EXABYTE_ENABLE_NEST                0xF0

#define WIN_SECURITY_SET_PASS                0xF1

#define WIN_SECURITY_UNLOCK                0xF2

#define WIN_SECURITY_ERASE_PREPARE        0xF3

#define WIN_SECURITY_ERASE_UNIT                0xF4

#define WIN_SECURITY_FREEZE_LOCK        0xF5

#define WIN_SECURITY_DISABLE                0xF6

#define WIN_READ_NATIVE_MAX                0xF8 /* return the native maximum address */

#define WIN_SET_MAX                        0xF9

#define DISABLE_SEAGATE                        0xFB

/* set to 1 set disable mult support */

#define MAX_MULT_SECTORS 16

/* ATAPI defines */

#define ATAPI_PACKET_SIZE 12

/* The generic packet command opcodes for CD/DVD Logical Units,

 * From Table 57 of the SFF8090 Ver. 3 (Mt. Fuji) draft standard. */

#define GPCMD_BLANK                            0xa1

#define GPCMD_CLOSE_TRACK                    0x5b

#define GPCMD_FLUSH_CACHE                    0x35

#define GPCMD_FORMAT_UNIT                    0x04

#define GPCMD_GET_CONFIGURATION                    0x46

#define GPCMD_GET_EVENT_STATUS_NOTIFICATION 0x4a

#define GPCMD_GET_PERFORMANCE                    0xac

#define GPCMD_INQUIRY                            0x12

#define GPCMD_LOAD_UNLOAD                    0xa6

#define GPCMD_MECHANISM_STATUS                    0xbd

#define GPCMD_MODE_SELECT_10                    0x55

#define GPCMD_MODE_SENSE_10                    0x5a

#define GPCMD_PAUSE_RESUME                    0x4b

#define GPCMD_PLAY_AUDIO_10                    0x45

#define GPCMD_PLAY_AUDIO_MSF                    0x47

#define GPCMD_PLAY_AUDIO_TI                    0x48

#define GPCMD_PLAY_CD                            0xbc

#define GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL  0x1e

#define GPCMD_READ_10                            0x28

#define GPCMD_READ_12                            0xa8

#define GPCMD_READ_CDVD_CAPACITY            0x25

#define GPCMD_READ_CD                            0xbe

#define GPCMD_READ_CD_MSF                    0xb9

#define GPCMD_READ_DISC_INFO                    0x51

#define GPCMD_READ_DVD_STRUCTURE            0xad

#define GPCMD_READ_FORMAT_CAPACITIES            0x23

#define GPCMD_READ_HEADER                    0x44

#define GPCMD_READ_TRACK_RZONE_INFO            0x52

#define GPCMD_READ_SUBCHANNEL                    0x42

#define GPCMD_READ_TOC_PMA_ATIP                    0x43

#define GPCMD_REPAIR_RZONE_TRACK            0x58

#define GPCMD_REPORT_KEY                    0xa4

#define GPCMD_REQUEST_SENSE                    0x03

#define GPCMD_RESERVE_RZONE_TRACK            0x53

#define GPCMD_SCAN                            0xba

#define GPCMD_SEEK                            0x2b

#define GPCMD_SEND_DVD_STRUCTURE            0xad

#define GPCMD_SEND_EVENT                    0xa2

#define GPCMD_SEND_KEY                            0xa3

#define GPCMD_SEND_OPC                            0x54

#define GPCMD_SET_READ_AHEAD                    0xa7

#define GPCMD_SET_STREAMING                    0xb6

#define GPCMD_START_STOP_UNIT                    0x1b

#define GPCMD_STOP_PLAY_SCAN                    0x4e

#define GPCMD_TEST_UNIT_READY                    0x00

#define GPCMD_VERIFY_10                            0x2f

#define GPCMD_WRITE_10                            0x2a

#define GPCMD_WRITE_AND_VERIFY_10            0x2e

/* This is listed as optional in ATAPI 2.6, but is (curiously) 

 * missing from Mt. Fuji, Table 57.  It _is_ mentioned in Mt. Fuji

 * Table 377 as an MMC command for SCSi devices though...  Most ATAPI

 * drives support it. */

#define GPCMD_SET_SPEED                            0xbb

/* This seems to be a SCSI specific CD-ROM opcode 

 * to play data at track/index */

#define GPCMD_PLAYAUDIO_TI                    0x48

/*

 * From MS Media Status Notification Support Specification. For

 * older drives only.

 */

#define GPCMD_GET_MEDIA_STATUS                    0xda

/* Mode page codes for mode sense/set */

#define GPMODE_R_W_ERROR_PAGE                0x01

#define GPMODE_WRITE_PARMS_PAGE                0x05

#define GPMODE_AUDIO_CTL_PAGE                0x0e

#define GPMODE_POWER_PAGE                0x1a

#define GPMODE_FAULT_FAIL_PAGE                0x1c

#define GPMODE_TO_PROTECT_PAGE                0x1d

#define GPMODE_CAPABILITIES_PAGE        0x2a

#define GPMODE_ALL_PAGES                0x3f

/* Not in Mt. Fuji, but in ATAPI 2.6 -- depricated now in favor

 * of MODE_SENSE_POWER_PAGE */

#define GPMODE_CDROM_PAGE                0x0d

#define ATAPI_INT_REASON_CD             0x01 /* 0 = data transfer */

#define ATAPI_INT_REASON_IO             0x02 /* 1 = transfer to the host */

#define ATAPI_INT_REASON_REL            0x04

#define ATAPI_INT_REASON_TAG            0xf8

/* same constants as bochs */

#define ASC_ILLEGAL_OPCODE                   0x20

#define ASC_LOGICAL_BLOCK_OOR                0x21

#define ASC_INV_FIELD_IN_CMD_PACKET          0x24

#define ASC_MEDIUM_NOT_PRESENT               0x3a

#define ASC_SAVING_PARAMETERS_NOT_SUPPORTED  0x39

#define SENSE_NONE            0

#define SENSE_NOT_READY       2

#define SENSE_ILLEGAL_REQUEST 5

#define SENSE_UNIT_ATTENTION  6

struct IDEState;

typedef void EndTransferFunc(struct IDEState *);

/* NOTE: IDEState represents in fact one drive */

typedef struct IDEState {

    /* ide config */

    int is_cdrom;

    int cylinders, heads, sectors;

    int64_t nb_sectors;

    int mult_sectors;

    int irq;

    PCIDevice *pci_dev;

    int drive_serial;

    /* ide regs */

    uint8_t feature;

    uint8_t error;

    uint16_t nsector; /* 0 is 256 to ease computations */

    uint8_t sector;

    uint8_t lcyl;

    uint8_t hcyl;

    uint8_t select;

    uint8_t status;

    /* 0x3f6 command, only meaningful for drive 0 */

    uint8_t cmd;

    /* depends on bit 4 in select, only meaningful for drive 0 */

    struct IDEState *cur_drive; 

    BlockDriverState *bs;

    /* ATAPI specific */

    uint8_t sense_key;

    uint8_t asc;

    int packet_transfer_size;

    int elementary_transfer_size;

    int io_buffer_index;

    int lba;

    /* transfer handling */

    int req_nb_sectors; /* number of sectors per interrupt */

    EndTransferFunc *end_transfer_func;

    uint8_t *data_ptr;

    uint8_t *data_end;

    uint8_t io_buffer[MAX_MULT_SECTORS*512 + 4];

} IDEState;

static void padstr(char *str, const char *src, int len)

{

    int i, v;

    for(i = 0; i < len; i++) {

        if (*src)

            v = *src++;

        else

            v = ' ';

        *(char *)((long)str ^ 1) = v;

        str++;

    }

}

static void padstr8(uint8_t *buf, int buf_size, const char *src)

{

    int i;

    for(i = 0; i < buf_size; i++) {

        if (*src)

            buf[i] = *src++;

        else

            buf[i] = ' ';

    }

}

static void put_le16(uint16_t *p, unsigned int v)

{

    *p = cpu_to_le16(v);

}

static void ide_identify(IDEState *s)

{

    uint16_t *p;

    unsigned int oldsize;

    char buf[20];

    memset(s->io_buffer, 0, 512);

    p = (uint16_t *)s->io_buffer;

    put_le16(p + 0, 0x0040);

    put_le16(p + 1, s->cylinders); 

    put_le16(p + 3, s->heads);

    put_le16(p + 4, 512 * s->sectors); /* XXX: retired, remove ? */

    put_le16(p + 5, 512); /* XXX: retired, remove ? */

    put_le16(p + 6, s->sectors); 

    snprintf(buf, sizeof(buf), "QM%05d", s->drive_serial);

    padstr((uint8_t *)(p + 10), buf, 20); /* serial number */

    put_le16(p + 20, 3); /* XXX: retired, remove ? */

    put_le16(p + 21, 512); /* cache size in sectors */

    put_le16(p + 22, 4); /* ecc bytes */

    padstr((uint8_t *)(p + 23), QEMU_VERSION, 8); /* firmware version */

    padstr((uint8_t *)(p + 27), "QEMU HARDDISK", 40); /* model */

#if MAX_MULT_SECTORS > 1    

    put_le16(p + 47, 0x8000 | MAX_MULT_SECTORS);

#endif

    put_le16(p + 48, 1); /* dword I/O */

    put_le16(p + 49, 1 << 9); /* LBA supported, no DMA */

    put_le16(p + 51, 0x200); /* PIO transfer cycle */

    put_le16(p + 52, 0x200); /* DMA transfer cycle */

    put_le16(p + 53, 1); /* words 54-58 are valid */

    put_le16(p + 54, s->cylinders);

    put_le16(p + 55, s->heads);

    put_le16(p + 56, s->sectors);

    oldsize = s->cylinders * s->heads * s->sectors;

    put_le16(p + 57, oldsize);

    put_le16(p + 58, oldsize >> 16);

    if (s->mult_sectors)

        put_le16(p + 59, 0x100 | s->mult_sectors);

    put_le16(p + 60, s->nb_sectors);

    put_le16(p + 61, s->nb_sectors >> 16);

    put_le16(p + 80, (1 << 1) | (1 << 2));

    put_le16(p + 82, (1 << 14));

    put_le16(p + 83, (1 << 14));

    put_le16(p + 84, (1 << 14));

    put_le16(p + 85, (1 << 14));

    put_le16(p + 86, 0);

    put_le16(p + 87, (1 << 14));

}

static void ide_atapi_identify(IDEState *s)

{

    uint16_t *p;

    char buf[20];

    memset(s->io_buffer, 0, 512);

    p = (uint16_t *)s->io_buffer;

    /* Removable CDROM, 50us response, 12 byte packets */

    put_le16(p + 0, (2 << 14) | (5 << 8) | (1 << 7) | (2 << 5) | (0 << 0));

    snprintf(buf, sizeof(buf), "QM%05d", s->drive_serial);

    padstr((uint8_t *)(p + 10), buf, 20); /* serial number */

    put_le16(p + 20, 3); /* buffer type */

    put_le16(p + 21, 512); /* cache size in sectors */

    put_le16(p + 22, 4); /* ecc bytes */

    padstr((uint8_t *)(p + 23), QEMU_VERSION, 8); /* firmware version */

    padstr((uint8_t *)(p + 27), "QEMU CD-ROM", 40); /* model */

    put_le16(p + 48, 1); /* dword I/O (XXX: should not be set on CDROM) */

    put_le16(p + 49, 1 << 9); /* LBA supported, no DMA */

    put_le16(p + 53, 3); /* words 64-70, 54-58 valid */

    put_le16(p + 63, 0x103); /* DMA modes XXX: may be incorrect */

    put_le16(p + 64, 1); /* PIO modes */

    put_le16(p + 65, 0xb4); /* minimum DMA multiword tx cycle time */

    put_le16(p + 66, 0xb4); /* recommended DMA multiword tx cycle time */

    put_le16(p + 67, 0x12c); /* minimum PIO cycle time without flow control */

    put_le16(p + 68, 0xb4); /* minimum PIO cycle time with IORDY flow control */

    put_le16(p + 71, 30); /* in ns */

    put_le16(p + 72, 30); /* in ns */

    put_le16(p + 80, 0x1e); /* support up to ATA/ATAPI-4 */

}

static void ide_set_signature(IDEState *s)

{

    s->select &= 0xf0; /* clear head */

    /* put signature */

    s->nsector = 1;

    s->sector = 1;

    if (s->is_cdrom) {

        s->lcyl = 0x14;

        s->hcyl = 0xeb;

    } else if (s->bs) {

        s->lcyl = 0;

        s->hcyl = 0;

    } else {

        s->lcyl = 0xff;

        s->hcyl = 0xff;

    }

}

static inline void ide_abort_command(IDEState *s)

{

    s->status = READY_STAT | ERR_STAT;

    s->error = ABRT_ERR;

}

static inline void ide_set_irq(IDEState *s)

{

    if (!(s->cmd & IDE_CMD_DISABLE_IRQ)) {

        if (s->irq == 16)

            pci_set_irq(s->pci_dev, 0, 1);

        else

            pic_set_irq(s->irq, 1);

    }

}

/* prepare data transfer and tell what to do after */

static void ide_transfer_start(IDEState *s, uint8_t *buf, int size, 

                               EndTransferFunc *end_transfer_func)

{

    s->end_transfer_func = end_transfer_func;

    s->data_ptr = buf;

    s->data_end = buf + size;

    s->status |= DRQ_STAT;

}

static void ide_transfer_stop(IDEState *s)

{

    s->end_transfer_func = ide_transfer_stop;

    s->data_ptr = s->io_buffer;

    s->data_end = s->io_buffer;

    s->status &= ~DRQ_STAT;

}

static int64_t ide_get_sector(IDEState *s)

{

    int64_t sector_num;

    if (s->select & 0x40) {

        /* lba */

        sector_num = ((s->select & 0x0f) << 24) | (s->hcyl << 16) | 

            (s->lcyl << 8) | s->sector;

    } else {

        sector_num = ((s->hcyl << 8) | s->lcyl) * s->heads * s->sectors +

            (s->select & 0x0f) * s->sectors + 

            (s->sector - 1);

    }

    return sector_num;

}

static void ide_set_sector(IDEState *s, int64_t sector_num)

{

    unsigned int cyl, r;

    if (s->select & 0x40) {

        s->select = (s->select & 0xf0) | (sector_num >> 24);

        s->hcyl = (sector_num >> 16);

        s->lcyl = (sector_num >> 8);

        s->sector = (sector_num);

    } else {

        cyl = sector_num / (s->heads * s->sectors);

        r = sector_num % (s->heads * s->sectors);

        s->hcyl = cyl >> 8;

        s->lcyl = cyl;

        s->select = (s->select & 0xf0) | ((r / s->sectors) & 0x0f);

        s->sector = (r % s->sectors) + 1;

    }

}

static void ide_sector_read(IDEState *s)

{

    int64_t sector_num;

    int ret, n;

    s->status = READY_STAT | SEEK_STAT;

    s->error = 0; /* not needed by IDE spec, but needed by Windows */

    sector_num = ide_get_sector(s);

    n = s->nsector;

    if (n == 0) {

        /* no more sector to read from disk */

        ide_transfer_stop(s);

    } else {

#if defined(DEBUG_IDE)

        printf("read sector=%Ld\n", sector_num);

#endif

        if (n > s->req_nb_sectors)

            n = s->req_nb_sectors;

        ret = bdrv_read(s->bs, sector_num, s->io_buffer, n);

        ide_transfer_start(s, s->io_buffer, 512 * n, ide_sector_read);

        ide_set_irq(s);

        ide_set_sector(s, sector_num + n);

        s->nsector -= n;

    }

}

static void ide_sector_write(IDEState *s)

{

    int64_t sector_num;

    int ret, n, n1;

    s->status = READY_STAT | SEEK_STAT;

    sector_num = ide_get_sector(s);

#if defined(DEBUG_IDE)

    printf("write sector=%Ld\n", sector_num);

#endif

    n = s->nsector;

    if (n > s->req_nb_sectors)

        n = s->req_nb_sectors;

    ret = bdrv_write(s->bs, sector_num, s->io_buffer, n);

    s->nsector -= n;

    if (s->nsector == 0) {

        /* no more sector to write */

        ide_transfer_stop(s);

    } else {

        n1 = s->nsector;

        if (n1 > s->req_nb_sectors)

            n1 = s->req_nb_sectors;

        ide_transfer_start(s, s->io_buffer, 512 * n1, ide_sector_write);

    }

    ide_set_sector(s, sector_num + n);

    ide_set_irq(s);

}

static void ide_atapi_cmd_ok(IDEState *s)

{

    s->error = 0;

    s->status = READY_STAT;

    s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;

    ide_set_irq(s);

}

static void ide_atapi_cmd_error(IDEState *s, int sense_key, int asc)

{

#ifdef DEBUG_IDE_ATAPI

    printf("atapi_cmd_error: sense=0x%x asc=0x%x\n", sense_key, asc);

#endif

    s->error = sense_key << 4;

    s->status = READY_STAT | ERR_STAT;

    s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;

    s->sense_key = sense_key;

    s->asc = asc;

    ide_set_irq(s);

}

static inline void cpu_to_ube16(uint8_t *buf, int val)

{

    buf[0] = val >> 8;

    buf[1] = val;

}

static inline void cpu_to_ube32(uint8_t *buf, unsigned int val)

{

    buf[0] = val >> 24;

    buf[1] = val >> 16;

    buf[2] = val >> 8;

    buf[3] = val;

}

static inline int ube16_to_cpu(const uint8_t *buf)

{

    return (buf[0] << 8) | buf[1];

}

static inline int ube32_to_cpu(const uint8_t *buf)

{

    return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];

}

/* The whole ATAPI transfer logic is handled in this function */

static void ide_atapi_cmd_reply_end(IDEState *s)

{

    int byte_count_limit, size;

#ifdef DEBUG_IDE_ATAPI

    printf("reply: tx_size=%d elem_tx_size=%d index=%d\n", 

           s->packet_transfer_size,

           s->elementary_transfer_size,

           s->io_buffer_index);

#endif

    if (s->packet_transfer_size <= 0) {

        /* end of transfer */

        ide_transfer_stop(s);

        s->status = READY_STAT;

        s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;

        ide_set_irq(s);

#ifdef DEBUG_IDE_ATAPI

        printf("status=0x%x\n", s->status);

#endif

    } else {

        /* see if a new sector must be read */

        if (s->lba != -1 && s->io_buffer_index >= 2048) {

            bdrv_read(s->bs, (int64_t)s->lba << 2, s->io_buffer, 4);

            s->lba++;

            s->io_buffer_index = 0;

        }

        if (s->elementary_transfer_size > 0) {

            /* there are some data left to transmit in this elementary

               transfer */

            size = 2048 - s->io_buffer_index;

            if (size > s->elementary_transfer_size)

                size = s->elementary_transfer_size;

            ide_transfer_start(s, s->io_buffer + s->io_buffer_index, 

                               size, ide_atapi_cmd_reply_end);

            s->packet_transfer_size -= size;

            s->elementary_transfer_size -= size;

            s->io_buffer_index += size;

        } else {

            /* a new transfer is needed */

            s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO;

            byte_count_limit = s->lcyl | (s->hcyl << 8);

#ifdef DEBUG_IDE_ATAPI

            printf("byte_count_limit=%d\n", byte_count_limit);

#endif

            if (byte_count_limit == 0xffff)

                byte_count_limit--;

            size = s->packet_transfer_size;

            if (size > byte_count_limit) {

                /* byte count limit must be even if this case */

                if (byte_count_limit & 1)

                    byte_count_limit--;

                size = byte_count_limit;

            }

            s->lcyl = size;

            s->hcyl = size >> 8;

            s->elementary_transfer_size = size;

            /* we cannot transmit more than one sector at a time */

            if (s->lba != -1) {

                if (size > (2048 - s->io_buffer_index))

                    size = (2048 - s->io_buffer_index);

            }

            ide_transfer_start(s, s->io_buffer + s->io_buffer_index, 

                               size, ide_atapi_cmd_reply_end);

            s->packet_transfer_size -= size;

            s->elementary_transfer_size -= size;

            s->io_buffer_index += size;

            ide_set_irq(s);

#ifdef DEBUG_IDE_ATAPI

            printf("status=0x%x\n", s->status);

#endif

        }

    }

}

/* send a reply of 'size' bytes in s->io_buffer to an ATAPI command */

static void ide_atapi_cmd_reply(IDEState *s, int size, int max_size)

{

    if (size > max_size)

        size = max_size;

    s->lba = -1; /* no sector read */

    s->packet_transfer_size = size;

    s->elementary_transfer_size = 0;

    s->io_buffer_index = 0;

    s->status = READY_STAT;

    ide_atapi_cmd_reply_end(s);

}

/* start a CD-CDROM read command */

static void ide_atapi_cmd_read(IDEState *s, int lba, int nb_sectors)

{

#ifdef DEBUG_IDE_ATAPI

    printf("read: LBA=%d nb_sectors=%d\n", lba, nb_sectors);

#endif

    s->lba = lba;

    s->packet_transfer_size = nb_sectors * 2048;

    s->elementary_transfer_size = 0;

    s->io_buffer_index = 2048;

    s->status = READY_STAT;

    ide_atapi_cmd_reply_end(s);

}

/* same toc as bochs. Return -1 if error or the toc length */

static int cdrom_read_toc(IDEState *s, uint8_t *buf, int msf, int start_track)

{

    uint8_t *q;

    int nb_sectors, len;

    if (start_track > 1 && start_track != 0xaa)

        return -1;

    q = buf + 2;

    *q++ = 1;

    *q++ = 1;

    if (start_track <= 1) {

        *q++ = 0; /* reserved */

        *q++ = 0x14; /* ADR, control */

        *q++ = 1;    /* track number */

        *q++ = 0; /* reserved */

        if (msf) {

            *q++ = 0; /* reserved */

            *q++ = 0; /* minute */

            *q++ = 2; /* second */

            *q++ = 0; /* frame */

        } else {

            /* sector 0 */

            cpu_to_ube32(q, 0);

            q += 4;

        }

    }

    /* lead out track */

    *q++ = 0; /* reserved */

    *q++ = 0x16; /* ADR, control */

    *q++ = 0xaa; /* track number */

    *q++ = 0; /* reserved */

    nb_sectors = s->nb_sectors >> 2;

    if (msf) {

        *q++ = 0; /* reserved */

        *q++ = ((nb_sectors + 150) / 75) / 60;

        *q++ = ((nb_sectors + 150) / 75) % 60;

        *q++ = (nb_sectors + 150) % 75;

    } else {

        cpu_to_ube32(q, nb_sectors);

        q += 4;

    }

    len = q - buf;

    cpu_to_ube16(buf, len - 2);

    return len;

}

static void ide_atapi_cmd(IDEState *s)

{

    const uint8_t *packet;

    uint8_t *buf;

    int max_len;

    packet = s->io_buffer;

    buf = s->io_buffer;

#ifdef DEBUG_IDE_ATAPI

    {

        int i;

        printf("ATAPI limit=0x%x packet:", s->lcyl | (s->hcyl << 8));

        for(i = 0; i < ATAPI_PACKET_SIZE; i++) {

            printf(" %02x", packet[i]);

        }

        printf("\n");

    }

#endif

    switch(s->io_buffer[0]) {

    case GPCMD_TEST_UNIT_READY:

        if (bdrv_is_inserted(s->bs)) {

            ide_atapi_cmd_ok(s);

        } else {

            ide_atapi_cmd_error(s, SENSE_NOT_READY, 

                                ASC_MEDIUM_NOT_PRESENT);

        }

        break;

    case GPCMD_MODE_SENSE_10:

        {

            int action, code;

            max_len = ube16_to_cpu(packet + 7);

            action = packet[2] >> 6;

            code = packet[2] & 0x3f;

            switch(action) {

            case 0: /* current values */

                switch(code) {

                case 0x01: /* error recovery */

                    cpu_to_ube16(&buf[0], 16 + 6);

                    buf[2] = 0x70;

                    buf[3] = 0;

                    buf[4] = 0;

                    buf[5] = 0;

                    buf[6] = 0;

                    buf[7] = 0;

                    buf[8] = 0x01;

                    buf[9] = 0x06;

                    buf[10] = 0x00;

                    buf[11] = 0x05;

                    buf[12] = 0x00;

                    buf[13] = 0x00;

                    buf[14] = 0x00;

                    buf[15] = 0x00;

                    ide_atapi_cmd_reply(s, 16, max_len);

                    break;

                case 0x2a:

                    cpu_to_ube16(&buf[0], 28 + 6);

                    buf[2] = 0x70;

                    buf[3] = 0;

                    buf[4] = 0;

                    buf[5] = 0;

                    buf[6] = 0;

                    buf[7] = 0;

                    buf[8] = 0x2a;

                    buf[9] = 0x12;

                    buf[10] = 0x00;

                    buf[11] = 0x00;

                    buf[12] = 0x70;

                    buf[13] = 3 << 5;