Subversion Repositories freemyipod

/***************************************************************************

 *             __________               __   ___.

 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___

 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /

 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <

 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \

 *                     \/            \/     \/    \/            \/

 * $Id: disk.c 26629 2010-06-06 13:28:13Z gevaerts $

 *

 * Copyright (C) 2002 by Björn Stenberg

 *

 * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 ****************************************************************************/

#include "global.h"

#include "thread.h"

#include "storage.h"

#include "debug.h"

#include "fat.h"

#ifdef HAVE_HOTSWAP

#include "dir.h" /* for release_dirs() */

#include "file.h" /* for release_files() */

#endif

#include "disk.h"

#include "util.h"

#include "libc/include/string.h"

/* Partition table entry layout:

   -----------------------

   0: 0x80 - active

   1: starting head

   2: starting sector

   3: starting cylinder

   4: partition type

   5: end head

   6: end sector

   7: end cylinder

   8-11: starting sector (LBA)

   12-15: nr of sectors in partition

*/

#define BYTES2INT32(array,pos)                  \

    ((long)array[pos] | ((long)array[pos+1] << 8 ) |        \

     ((long)array[pos+2] << 16 ) | ((long)array[pos+3] << 24 ))

static const unsigned char fat_partition_types[] = {

    0x0b, 0x1b, /* FAT32 + hidden variant */

    0x0c, 0x1c, /* FAT32 (LBA) + hidden variant */

#ifdef HAVE_FAT16SUPPORT

    0x04, 0x14, /* FAT16 <= 32MB + hidden variant */

    0x06, 0x16, /* FAT16  > 32MB + hidden variant */

    0x0e, 0x1e, /* FAT16 (LBA) + hidden variant */

#endif

};

static struct partinfo part[NUM_DRIVES*4]; /* space for 4 partitions on 2 drives */

static int vol_drive[NUM_VOLUMES]; /* mounted to which drive (-1 if none) */

static struct mutex disk_mutex;

struct partinfo* disk_init(IF_MD_NONVOID(int drive))

{

    int i;

#ifdef HAVE_MULTIDRIVE

    /* For each drive, start at a different position, in order not to destroy

       the first entry of drive 0.

       That one is needed to calculate config sector position. */

    struct partinfo* pinfo = &part[drive*4];

    if ((size_t)drive >= sizeof(part)/sizeof(*part)/4)

        return NULL; /* out of space in table */

#else

    struct partinfo* pinfo = part;

    const int drive = 0;

    (void)drive;

#endif

    unsigned char* sector = fat_get_sector_buffer();

    storage_read_sectors(IF_MD2(drive,) 0,1, sector);

    /* check that the boot sector is initialized */

    if ( (sector[510] != 0x55) ||

         (sector[511] != 0xaa)) {

        fat_release_sector_buffer();

        DEBUGF("Bad boot sector signature");

        return NULL;

    }

    /* parse partitions */

    for ( i=0; i<4; i++ ) {

        unsigned char* ptr = sector + 0x1be + 16*i;

        pinfo[i].type  = ptr[4];

        pinfo[i].start = BYTES2INT32(ptr, 8);

        pinfo[i].size  = BYTES2INT32(ptr, 12);

        DEBUGF("Part%d: Type %02x, start: %08lx size: %08lx",

               i,pinfo[i].type,pinfo[i].start,pinfo[i].size);

        /* extended? */

        if ( pinfo[i].type == 5 ) {

            /* not handled yet */

        }

    }

    fat_release_sector_buffer();

    return pinfo;

}

struct partinfo* disk_partinfo(int partition)

{

    return &part[partition];

}

void disk_init_subsystem(void)

{

   mutex_init(&disk_mutex);

}

int disk_mount_all(void)

{

    int mounted=0;

    int i;

#ifdef HAVE_HOTSWAP

    mutex_lock(&disk_mutex);

#endif

    fat_init(); /* reset all mounted partitions */

    for (i=0; i<NUM_VOLUMES; i++)

        vol_drive[i] = -1; /* mark all as unassigned */

#ifndef HAVE_MULTIDRIVE

    mounted = disk_mount(0);

#else

    for(i=0;i<NUM_DRIVES;i++)

    {

#ifdef HAVE_HOTSWAP

        if (storage_present(i))

#endif

            mounted += disk_mount(i); 

    }

#endif

#ifdef HAVE_HOTSWAP

    mutex_unlock(&disk_mutex);

#endif

    return mounted;

}

static int get_free_volume(void)

{

    int i;

    for (i=0; i<NUM_VOLUMES; i++)

    {

        if (vol_drive[i] == -1) /* unassigned? */

            return i;

    }

    return -1; /* none found */

}

int disk_mount(int drive)

{

    int i;

    int mounted = 0; /* reset partition-on-drive flag */

    int volume;

    struct partinfo* pinfo;

#ifdef HAVE_HOTSWAP

    mutex_lock(&disk_mutex);

#endif

    volume = get_free_volume();

    pinfo = disk_init(IF_MD(drive));

    if (pinfo == NULL)

    {

#ifdef HAVE_HOTSWAP

        mutex_unlock(&disk_mutex);

#endif

        return 0;

    }

    for (i = 0; volume != -1 && i<4 && mounted<NUM_VOLUMES_PER_DRIVE; i++)

    {

        if (memchr(fat_partition_types, pinfo[i].type,

                   sizeof(fat_partition_types)) == NULL)

            continue;  /* not an accepted partition type */

        if (!fat_mount(IF_MV2(volume,) IF_MD2(drive,) pinfo[i].start))

        {

            mounted++;

            vol_drive[volume] = drive; /* remember the drive for this volume */

            volume = get_free_volume(); /* prepare next entry */

        }

    }

    if (mounted == 0 && volume != -1) /* none of the 4 entries worked? */

    {   /* try "superfloppy" mode */

        DEBUGF("No partition found, trying to mount sector 0.");

        if (!fat_mount(IF_MV2(volume,) IF_MD2(drive,) 0))

        {

            mounted = 1;

            vol_drive[volume] = drive; /* remember the drive for this volume */

        }

    }

#ifdef HAVE_HOTSWAP

    mutex_unlock(&disk_mutex);

#endif

    return mounted;

}

#ifdef HAVE_HOTSWAP

int disk_unmount(int drive)

{

    int unmounted = 0;

    int i;

    mutex_lock(&disk_mutex);

    for (i=0; i<NUM_VOLUMES; i++)

    {

        if (vol_drive[i] == drive)

        {   /* force releasing resources */

            vol_drive[i] = -1; /* mark unused */

            unmounted++;

            release_files(i);

            release_dirs(i);

            fat_unmount(i, false);

        }

    }

    mutex_unlock(&disk_mutex);

    return unmounted;

}

#endif /* #ifdef HAVE_HOTSWAP */