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[/] [or1k/] [trunk/] [rtems-20020807/] [cpukit/] [libfs/] [src/] [dosfs/] [fat.h] - Blame information for rev 1765

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/*
 *  fat.h
 *
 *  Constants/data structures/prototypes for low-level operations on a volume
 *  with FAT filesystem
 *
 *  Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
 *  Author: Eugeny S. Mints <Eugeny.Mints@oktet.ru>
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.OARcorp.com/rtems/license.html.
 *
 *  @(#) fat.h,v 1.2 2002/04/04 18:22:23 joel Exp
 */
 
#ifndef __DOSFS_FAT_H__
#define __DOSFS_FAT_H__
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include <string.h>
 
#include <rtems/seterr.h>
 
/* XXX: temporary hack :(( */
#ifndef set_errno_and_return_minus_one
#define set_errno_and_return_minus_one rtems_set_errno_and_return_minus_one
#endif /* set_errno_and_return_minus_one */
 
#include <rtems/score/cpu.h>
#include <errno.h>
#include <rtems/bdbuf.h>
 
#ifndef RC_OK
#define RC_OK 0x00000000
#endif
 
/*
 * Remember that all FAT file system on disk data structure is
 * "little endian"!
 * (derived from linux)
 */
/*
 * Conversion from and to little-endian byte order. (no-op on i386/i486)
 *
 * Naming: Ca_b_c, where a: F = from, T = to, b: LE = little-endian,
 * BE = big-endian, c: W = word (16 bits), L = longword (32 bits)
 */
 
#if (CPU_BIG_ENDIAN == TRUE)
#    define CF_LE_W(v) CPU_swap_u16(v)
#    define CF_LE_L(v) CPU_swap_u32(v)
#    define CT_LE_W(v) CPU_swap_u16(v)
#    define CT_LE_L(v) CPU_swap_u32(v)
#else  
#    define CF_LE_W(v) (v)
#    define CF_LE_L(v) (v)
#    define CT_LE_W(v) (v)
#    define CT_LE_L(v) (v)
#endif  
 
#define MIN(a, b)  (((a) < (b)) ? (a) : (b))
 
#define FAT_HASH_SIZE   2
#define FAT_HASH_MODULE FAT_HASH_SIZE
 
 
#define FAT_SECTOR512_SIZE     512 /* sector size (bytes) */
#define FAT_SECTOR512_BITS       9 /* log2(SECTOR_SIZE) */
 
/* maximum + 1 number of clusters for FAT12 */
#define FAT_FAT12_MAX_CLN      4085 
 
/* maximum + 1 number of clusters for FAT16 */
#define FAT_FAT16_MAX_CLN      65525 
 
#define FAT_FAT12              0x01
#define FAT_FAT16              0x02
#define FAT_FAT32              0x04
 
#define FAT_UNDEFINED_VALUE     0xFFFFFFFF 
 
#define FAT_FAT12_EOC          0x0FFF
#define FAT_FAT16_EOC          0xFFFF
#define FAT_FAT32_EOC          0x0FFFFFFF
 
#define FAT_FAT12_FREE         0x0000
#define FAT_FAT16_FREE         0x0000
#define FAT_FAT32_FREE         0x00000000
 
#define FAT_GENFAT_EOC         0xFFFFFFFF
#define FAT_GENFAT_FREE        0x00000000
 
#define FAT_FAT12_SHIFT        0x04
 
#define FAT_FAT12_MASK         0x00000FFF
#define FAT_FAT16_MASK         0x0000FFFF
#define FAT_FAT32_MASK         0x0FFFFFFF
 
#define FAT_MAX_BPB_SIZE       90
 
/* size of useful information in FSInfo sector */
#define FAT_USEFUL_INFO_SIZE   12
 
#define FAT_VAL8(x, ofs)       (unsigned8)(*((unsigned8 *)(x) + (ofs)))
 
#define FAT_VAL16(x, ofs)                                   \
    (unsigned16)( (*((unsigned8 *)(x) + (ofs))) |           \
                  ((*((unsigned8 *)(x) + (ofs) + 1)) << 8) )
 
#define FAT_VAL32(x, ofs)                                          \
    (unsigned32)( (*((unsigned8 *)(x) + (ofs))) |                  \
                  ((*((unsigned8 *)(x) + (ofs) + 1)) << 8) |       \
                  ((*((unsigned8 *)(x) + (ofs) + 2)) << 16) |      \
                  ((*((unsigned8 *)(x) + (ofs) + 3)) << 24) )
 
/* macros to access boot sector fields */
#define FAT_BR_BYTES_PER_SECTOR(x)       FAT_VAL16(x, 11)
#define FAT_BR_SECTORS_PER_CLUSTER(x)    FAT_VAL8(x, 13) 
#define FAT_BR_RESERVED_SECTORS_NUM(x)   FAT_VAL16(x, 14)
#define FAT_BR_FAT_NUM(x)                FAT_VAL8(x, 16)
#define FAT_BR_FILES_PER_ROOT_DIR(x)     FAT_VAL16(x, 17)
#define FAT_BR_TOTAL_SECTORS_NUM16(x)    FAT_VAL16(x, 19)
#define FAT_BR_MEDIA(x)                  FAT_VAL8(x, 21) 
#define FAT_BR_SECTORS_PER_FAT(x)        FAT_VAL16(x, 22)
#define FAT_BR_TOTAL_SECTORS_NUM32(x)    FAT_VAL32(x, 32)
#define FAT_BR_SECTORS_PER_FAT32(x)      FAT_VAL32(x, 36)
#define FAT_BR_EXT_FLAGS(x)              FAT_VAL16(x, 40)
#define FAT_BR_FAT32_ROOT_CLUSTER(x)     FAT_VAL32(x, 44)
#define FAT_BR_FAT32_FS_INFO_SECTOR(x)   FAT_VAL16(x, 48)
#define FAT_FSINFO_LEAD_SIGNATURE(x)     FAT_VAL32(x, 0)
/*
 * I read FSInfo sector from offset 484 to access the information, so offsets
 * of these fields a relative
 */
#define FAT_FSINFO_FREE_CLUSTER_COUNT(x) FAT_VAL32(x, 4)
#define FAT_FSINFO_NEXT_FREE_CLUSTER(x)  FAT_VAL32(x, 8)
 
#define FAT_FSINFO_FREE_CLUSTER_COUNT_OFFSET 488
 
#define FAT_FSINFO_NEXT_FREE_CLUSTER_OFFSET  492
 
#define FAT_RSRVD_CLN                        0x02  
 
#define FAT_FSINFO_LEAD_SIGNATURE_VALUE      0x41615252
 
#define FAT_FSI_LEADSIG_SIZE                 0x04
 
#define FAT_FSI_INFO                         484
 
#define MS_BYTES_PER_CLUSTER_LIMIT           0x8000     /* 32K */
 
#define FAT_BR_EXT_FLAGS_MIRROR              0x0080
 
#define FAT_BR_EXT_FLAGS_FAT_NUM             0x000F
 
 
#define FAT_DIRENTRY_SIZE          32 
 
#define FAT_DIRENTRIES_PER_SEC512  16
 
/*
 * Volume descriptor
 * Description of the volume the FAT filesystem is located on - generally
 * the fields of the structure corresponde to Boot Sector and BPB Srtucture
 * (see M$ White Paper) fields
 */
typedef struct fat_vol_s
{
    unsigned16   bps;            /* bytes per sector */
    unsigned8    sec_log2;       /* log2 of bps */
    unsigned8    sec_mul;        /* log2 of 512bts sectors number per sector */
    unsigned8    spc;            /* sectors per cluster */
    unsigned8    spc_log2;       /* log2 of spc */
    unsigned16   bpc;            /* bytes per cluster */
    unsigned8    bpc_log2;       /* log2 of bytes per cluster */
    unsigned8    fats;           /* number of FATs */
    unsigned8    type;           /* FAT type */
    unsigned32   mask;
    unsigned32   eoc_val;
    unsigned16   fat_loc;        /* FAT start */
    unsigned32   fat_length;     /* sectors per FAT */
    unsigned32   rdir_loc;       /* root directory start */
    unsigned16   rdir_entrs;     /* files per root directory */
    unsigned32   rdir_secs;      /* sectors per root directory */
    unsigned32   rdir_size;      /* root directory size in bytes */
    unsigned32   tot_secs;       /* total count of sectors */
    unsigned32   data_fsec;      /* first data sector */
    unsigned32   data_cls;       /* count of data clusters */
    unsigned32   rdir_cl;        /* first cluster of the root directory */
    unsigned16   info_sec;       /* FSInfo Sector Structure location */
    unsigned32   free_cls;       /* last known free clusters count */
    unsigned32   next_cl;        /* next free cluster number */
    unsigned8    mirror;         /* mirroring enabla/disable */
    unsigned32   afat_loc;       /* active FAT location */
    unsigned8    afat;           /* the number of active FAT */
    dev_t        dev;            /* device ID */
    disk_device *dd;             /* disk device (see libblock) */
    void        *private_data;   /* reserved */
} fat_vol_t;
 
 
typedef struct fat_cache_s
{
    unsigned32     blk_num;
    rtems_boolean  modified;
    unsigned8      state;
    bdbuf_buffer   *buf;
} fat_cache_t;
 
/*
 * This structure identifies the instance of the filesystem on the FAT
 * ("fat-file") level.
 */
typedef struct fat_fs_info_s
{
    fat_vol_t      vol;           /* volume descriptor */
    Chain_Control *vhash;         /* "vhash" of fat-file descriptors */
    Chain_Control *rhash;         /* "rhash" of fat-file descriptors */
    char          *uino;          /* array of unique ino numbers */
    unsigned32     index;
    unsigned32     uino_pool_size; /* size */
    unsigned32     uino_base;
    fat_cache_t    c;             /* cache */
    unsigned8     *sec_buf; /* just placeholder for anything */
} fat_fs_info_t;
 
/*
 * if the name we looking for is file we store not only first data cluster
 * number, but and cluster number and offset for directory entry for this
 * name
 */
typedef struct fat_auxiliary_s
{
    unsigned32 cln;
    unsigned32 ofs;
} fat_auxiliary_t;
 
#define FAT_FAT_OFFSET(fat_type, cln)                  \
    ((fat_type) & FAT_FAT12 ? ((cln) + ((cln) >> 1)) : \
     (fat_type) & FAT_FAT16 ? ((cln) << 1)           : \
     ((cln) << 2))
 
#define FAT_CLUSTER_IS_ODD(n)  ((n) & 0x0001)
 
#define FAT12_SHIFT      0x4    /* half of a byte */
 
/* initial size of array of unique ino */
#define FAT_UINO_POOL_INIT_SIZE  0x100
 
/* cache support */
#define FAT_CACHE_EMPTY   0x0
#define FAT_CACHE_ACTUAL  0x1
 
#define FAT_OP_TYPE_READ  0x1
#define FAT_OP_TYPE_GET   0x2
 
static inline unsigned32
fat_cluster_num_to_sector_num(
    rtems_filesystem_mount_table_entry_t *mt_entry,
    unsigned32                            cln
    )
{
    register fat_fs_info_t *fs_info = mt_entry->fs_info;
 
    if ( (cln == 0) && (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16)) )
        return fs_info->vol.rdir_loc;
 
    return (((cln - FAT_RSRVD_CLN) << fs_info->vol.spc_log2) +
            fs_info->vol.data_fsec);
}
 
static inline unsigned32
fat_cluster_num_to_sector512_num(
    rtems_filesystem_mount_table_entry_t *mt_entry,
    unsigned32                            cln
    )
{
    fat_fs_info_t *fs_info = mt_entry->fs_info;
 
    if (cln == 1)
        return 1;
 
    return (fat_cluster_num_to_sector_num(mt_entry, cln) <<
            fs_info->vol.sec_mul);
}
 
static inline int
fat_buf_access(fat_fs_info_t *fs_info, unsigned32 blk, int op_type,
               bdbuf_buffer **buf)
{
    rtems_status_code sc = RTEMS_SUCCESSFUL;
    unsigned8         i;
    rtems_boolean     sec_of_fat;
 
 
    if (fs_info->c.state == FAT_CACHE_EMPTY)
    {
        if (op_type == FAT_OP_TYPE_READ)
            sc = rtems_bdbuf_read(fs_info->vol.dev, blk, &fs_info->c.buf);
        else
            sc = rtems_bdbuf_get(fs_info->vol.dev, blk, &fs_info->c.buf);
        if (sc != RTEMS_SUCCESSFUL)
            set_errno_and_return_minus_one(EIO);
        fs_info->c.blk_num = blk;
        fs_info->c.state = FAT_CACHE_ACTUAL;
    }
 
    sec_of_fat = ((fs_info->c.blk_num >= fs_info->vol.fat_loc) &&
                  (fs_info->c.blk_num < fs_info->vol.rdir_loc));
 
    if (fs_info->c.blk_num != blk)
    {
        if (fs_info->c.modified)
        {
            if (sec_of_fat && !fs_info->vol.mirror)
                memcpy(fs_info->sec_buf, fs_info->c.buf->buffer,
                       fs_info->vol.bps);
 
            sc = rtems_bdbuf_release_modified(fs_info->c.buf);
            if (sc != RTEMS_SUCCESSFUL)
                set_errno_and_return_minus_one(EIO);
            fs_info->c.modified = 0;
 
            if (sec_of_fat && !fs_info->vol.mirror)
            {
                bdbuf_buffer *b;
 
                for (i = 1; i < fs_info->vol.fats; i++)
                {
                    sc = rtems_bdbuf_get(fs_info->vol.dev,
                                         fs_info->c.blk_num +
                                         fs_info->vol.fat_length * i,
                                         &b);
                    if ( sc != RTEMS_SUCCESSFUL)
                        set_errno_and_return_minus_one(ENOMEM);
                    memcpy(b->buffer, fs_info->sec_buf, fs_info->vol.bps);
                    sc = rtems_bdbuf_release_modified(b);
                    if ( sc != RTEMS_SUCCESSFUL)
                        set_errno_and_return_minus_one(ENOMEM);
                }
            }
        }
        else
        {
            sc = rtems_bdbuf_release(fs_info->c.buf);
            if (sc != RTEMS_SUCCESSFUL)
                set_errno_and_return_minus_one(EIO);
 
        }
        if (op_type == FAT_OP_TYPE_READ)
            sc = rtems_bdbuf_read(fs_info->vol.dev, blk, &fs_info->c.buf);
        else
            sc = rtems_bdbuf_get(fs_info->vol.dev, blk, &fs_info->c.buf);
        if (sc != RTEMS_SUCCESSFUL)
            set_errno_and_return_minus_one(EIO);
        fs_info->c.blk_num = blk;
    }
    *buf = fs_info->c.buf;
    return RC_OK;
}
 
 
static inline int
fat_buf_release(fat_fs_info_t *fs_info)
{
    rtems_status_code sc = RTEMS_SUCCESSFUL;
    unsigned8         i;
    rtems_boolean     sec_of_fat;
 
    if (fs_info->c.state == FAT_CACHE_EMPTY)
        return RC_OK;
 
    sec_of_fat = ((fs_info->c.blk_num >= fs_info->vol.fat_loc) &&
                  (fs_info->c.blk_num < fs_info->vol.rdir_loc));
 
    if (fs_info->c.modified)
    {
        if (sec_of_fat && !fs_info->vol.mirror)
            memcpy(fs_info->sec_buf, fs_info->c.buf->buffer, fs_info->vol.bps);
 
        sc = rtems_bdbuf_release_modified(fs_info->c.buf);
        if (sc != RTEMS_SUCCESSFUL)
            set_errno_and_return_minus_one(EIO);
        fs_info->c.modified = 0;
 
        if (sec_of_fat && !fs_info->vol.mirror)
        {
            bdbuf_buffer *b;
 
            for (i = 1; i < fs_info->vol.fats; i++)
            {
                sc = rtems_bdbuf_get(fs_info->vol.dev,
                                     fs_info->c.blk_num +
                                     fs_info->vol.fat_length * i,
                                     &b);
                if ( sc != RTEMS_SUCCESSFUL)
                    set_errno_and_return_minus_one(ENOMEM);
                memcpy(b->buffer, fs_info->sec_buf, fs_info->vol.bps);
                sc = rtems_bdbuf_release_modified(b);
                if ( sc != RTEMS_SUCCESSFUL)
                    set_errno_and_return_minus_one(ENOMEM);
            }
        }
    }
    else
    {
        sc = rtems_bdbuf_release(fs_info->c.buf);
        if (sc != RTEMS_SUCCESSFUL)
            set_errno_and_return_minus_one(EIO);
    }
    fs_info->c.state = FAT_CACHE_EMPTY;
    return RC_OK;
}
 
static inline void
fat_buf_mark_modified(fat_fs_info_t *fs_info)
{
    fs_info->c.modified = TRUE;
}
 
 
 
ssize_t
_fat_block_read(rtems_filesystem_mount_table_entry_t *mt_entry,
                unsigned32                            start,
                unsigned32                            offset,
                unsigned32                            count,
                void                                 *buff);
 
ssize_t
_fat_block_write(rtems_filesystem_mount_table_entry_t *mt_entry,
                 unsigned32                            start,
                 unsigned32                            offset,
                 unsigned32                            count,
                 const void                           *buff);
 
ssize_t
fat_cluster_read(rtems_filesystem_mount_table_entry_t *mt_entry,
                  unsigned32                           cln,
                  void                                *buff);
 
ssize_t
fat_cluster_write(rtems_filesystem_mount_table_entry_t *mt_entry,
                   unsigned32                           cln,
                   const void                          *buff);
 
int
fat_init_volume_info(rtems_filesystem_mount_table_entry_t *mt_entry);
 
int
fat_init_clusters_chain(rtems_filesystem_mount_table_entry_t *mt_entry,
                        unsigned32                            start_cln);
 
unsigned32
fat_cluster_num_to_sector_num(rtems_filesystem_mount_table_entry_t *mt_entry,
                              unsigned32                            cln);
 
int
fat_shutdown_drive(rtems_filesystem_mount_table_entry_t *mt_entry);
 
 
unsigned32
fat_get_unique_ino(rtems_filesystem_mount_table_entry_t *mt_entry);
 
rtems_boolean
fat_ino_is_unique(rtems_filesystem_mount_table_entry_t *mt_entry,
                  unsigned32                            ino);
 
void
fat_free_unique_ino(rtems_filesystem_mount_table_entry_t *mt_entry,
                    unsigned32                            ino);
 
int
fat_fat32_update_fsinfo_sector(
  rtems_filesystem_mount_table_entry_t *mt_entry,
  unsigned32                            free_count,
  unsigned32                            next_free
  );
 
#ifdef __cplusplus
}
#endif
 
#endif /* __DOSFS_FAT_H__ */

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[/] [or1k/] [trunk/] [rtems-20020807/] [cpukit/] [libfs/] [src/] [dosfs/] [fat.h] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1026	ivang	`/*`
2			`* fat.h`
3			`*`
4			`* Constants/data structures/prototypes for low-level operations on a volume`
5			`* with FAT filesystem`
6			`*`
7			`* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia`
8			`* Author: Eugeny S. Mints <Eugeny.Mints@oktet.ru>`
9			`*`
10			`* The license and distribution terms for this file may be`
11			`* found in the file LICENSE in this distribution or at`
12			`* http://www.OARcorp.com/rtems/license.html.`
13			`*`
14			`* @(#) fat.h,v 1.2 2002/04/04 18:22:23 joel Exp`
15			`*/`
16
17			`#ifndef __DOSFS_FAT_H__`
18			`#define __DOSFS_FAT_H__`
19
20			`#ifdef __cplusplus`
21			`extern "C" {`
22			`#endif`
23
24			`#include <string.h>`
25
26			`#include <rtems/seterr.h>`
27
28			`/* XXX: temporary hack :(( */`
29			`#ifndef set_errno_and_return_minus_one`
30			`#define set_errno_and_return_minus_one rtems_set_errno_and_return_minus_one`
31			`#endif /* set_errno_and_return_minus_one */`
32
33			`#include <rtems/score/cpu.h>`
34			`#include <errno.h>`
35			`#include <rtems/bdbuf.h>`
36
37			`#ifndef RC_OK`
38			`#define RC_OK 0x00000000`
39			`#endif`
40
41			`/*`
42			`* Remember that all FAT file system on disk data structure is`
43			`* "little endian"!`
44			`* (derived from linux)`
45			`*/`
46			`/*`
47			`* Conversion from and to little-endian byte order. (no-op on i386/i486)`
48			`*`
49			`* Naming: Ca_b_c, where a: F = from, T = to, b: LE = little-endian,`
50			`* BE = big-endian, c: W = word (16 bits), L = longword (32 bits)`
51			`*/`
52
53			`#if (CPU_BIG_ENDIAN == TRUE)`
54			`# define CF_LE_W(v) CPU_swap_u16(v)`
55			`# define CF_LE_L(v) CPU_swap_u32(v)`
56			`# define CT_LE_W(v) CPU_swap_u16(v)`
57			`# define CT_LE_L(v) CPU_swap_u32(v)`
58			`#else`
59			`# define CF_LE_W(v) (v)`
60			`# define CF_LE_L(v) (v)`
61			`# define CT_LE_W(v) (v)`
62			`# define CT_LE_L(v) (v)`
63			`#endif`
64
65			`#define MIN(a, b) (((a) < (b)) ? (a) : (b))`
66
67			`#define FAT_HASH_SIZE 2`
68			`#define FAT_HASH_MODULE FAT_HASH_SIZE`
69
70
71			`#define FAT_SECTOR512_SIZE 512 /* sector size (bytes) */`
72			`#define FAT_SECTOR512_BITS 9 /* log2(SECTOR_SIZE) */`
73
74			`/* maximum + 1 number of clusters for FAT12 */`
75			`#define FAT_FAT12_MAX_CLN 4085`
76
77			`/* maximum + 1 number of clusters for FAT16 */`
78			`#define FAT_FAT16_MAX_CLN 65525`
79
80			`#define FAT_FAT12 0x01`
81			`#define FAT_FAT16 0x02`
82			`#define FAT_FAT32 0x04`
83
84			`#define FAT_UNDEFINED_VALUE 0xFFFFFFFF`
85
86			`#define FAT_FAT12_EOC 0x0FFF`
87			`#define FAT_FAT16_EOC 0xFFFF`
88			`#define FAT_FAT32_EOC 0x0FFFFFFF`
89
90			`#define FAT_FAT12_FREE 0x0000`
91			`#define FAT_FAT16_FREE 0x0000`
92			`#define FAT_FAT32_FREE 0x00000000`
93
94			`#define FAT_GENFAT_EOC 0xFFFFFFFF`
95			`#define FAT_GENFAT_FREE 0x00000000`
96
97			`#define FAT_FAT12_SHIFT 0x04`
98
99			`#define FAT_FAT12_MASK 0x00000FFF`
100			`#define FAT_FAT16_MASK 0x0000FFFF`
101			`#define FAT_FAT32_MASK 0x0FFFFFFF`
102
103			`#define FAT_MAX_BPB_SIZE 90`
104
105			`/* size of useful information in FSInfo sector */`
106			`#define FAT_USEFUL_INFO_SIZE 12`
107
108			`#define FAT_VAL8(x, ofs) (unsigned8)(((unsigned8 )(x) + (ofs)))`
109
110			`#define FAT_VAL16(x, ofs) \`
111			`(unsigned16)( (((unsigned8 )(x) + (ofs))) \| \`
112			`((((unsigned8 )(x) + (ofs) + 1)) << 8) )`
113
114			`#define FAT_VAL32(x, ofs) \`
115			`(unsigned32)( (((unsigned8 )(x) + (ofs))) \| \`
116			`((((unsigned8 )(x) + (ofs) + 1)) << 8) \| \`
117			`((((unsigned8 )(x) + (ofs) + 2)) << 16) \| \`
118			`((((unsigned8 )(x) + (ofs) + 3)) << 24) )`
119
120			`/* macros to access boot sector fields */`
121			`#define FAT_BR_BYTES_PER_SECTOR(x) FAT_VAL16(x, 11)`
122			`#define FAT_BR_SECTORS_PER_CLUSTER(x) FAT_VAL8(x, 13)`
123			`#define FAT_BR_RESERVED_SECTORS_NUM(x) FAT_VAL16(x, 14)`
124			`#define FAT_BR_FAT_NUM(x) FAT_VAL8(x, 16)`
125			`#define FAT_BR_FILES_PER_ROOT_DIR(x) FAT_VAL16(x, 17)`
126			`#define FAT_BR_TOTAL_SECTORS_NUM16(x) FAT_VAL16(x, 19)`
127			`#define FAT_BR_MEDIA(x) FAT_VAL8(x, 21)`
128			`#define FAT_BR_SECTORS_PER_FAT(x) FAT_VAL16(x, 22)`
129			`#define FAT_BR_TOTAL_SECTORS_NUM32(x) FAT_VAL32(x, 32)`
130			`#define FAT_BR_SECTORS_PER_FAT32(x) FAT_VAL32(x, 36)`
131			`#define FAT_BR_EXT_FLAGS(x) FAT_VAL16(x, 40)`
132			`#define FAT_BR_FAT32_ROOT_CLUSTER(x) FAT_VAL32(x, 44)`
133			`#define FAT_BR_FAT32_FS_INFO_SECTOR(x) FAT_VAL16(x, 48)`
134			`#define FAT_FSINFO_LEAD_SIGNATURE(x) FAT_VAL32(x, 0)`
135			`/*`
136			`* I read FSInfo sector from offset 484 to access the information, so offsets`
137			`* of these fields a relative`
138			`*/`
139			`#define FAT_FSINFO_FREE_CLUSTER_COUNT(x) FAT_VAL32(x, 4)`
140			`#define FAT_FSINFO_NEXT_FREE_CLUSTER(x) FAT_VAL32(x, 8)`
141
142			`#define FAT_FSINFO_FREE_CLUSTER_COUNT_OFFSET 488`
143
144			`#define FAT_FSINFO_NEXT_FREE_CLUSTER_OFFSET 492`
145
146			`#define FAT_RSRVD_CLN 0x02`
147
148			`#define FAT_FSINFO_LEAD_SIGNATURE_VALUE 0x41615252`
149
150			`#define FAT_FSI_LEADSIG_SIZE 0x04`
151
152			`#define FAT_FSI_INFO 484`
153
154			`#define MS_BYTES_PER_CLUSTER_LIMIT 0x8000 /* 32K */`
155
156			`#define FAT_BR_EXT_FLAGS_MIRROR 0x0080`
157
158			`#define FAT_BR_EXT_FLAGS_FAT_NUM 0x000F`
159
160
161			`#define FAT_DIRENTRY_SIZE 32`
162
163			`#define FAT_DIRENTRIES_PER_SEC512 16`
164
165			`/*`
166			`* Volume descriptor`
167			`* Description of the volume the FAT filesystem is located on - generally`
168			`* the fields of the structure corresponde to Boot Sector and BPB Srtucture`
169			`* (see M$ White Paper) fields`
170			`*/`
171			`typedef struct fat_vol_s`
172			`{`
173			`unsigned16 bps; /* bytes per sector */`
174			`unsigned8 sec_log2; /* log2 of bps */`
175			`unsigned8 sec_mul; /* log2 of 512bts sectors number per sector */`
176			`unsigned8 spc; /* sectors per cluster */`
177			`unsigned8 spc_log2; /* log2 of spc */`
178			`unsigned16 bpc; /* bytes per cluster */`
179			`unsigned8 bpc_log2; /* log2 of bytes per cluster */`
180			`unsigned8 fats; /* number of FATs */`
181			`unsigned8 type; /* FAT type */`
182			`unsigned32 mask;`
183			`unsigned32 eoc_val;`
184			`unsigned16 fat_loc; /* FAT start */`
185			`unsigned32 fat_length; /* sectors per FAT */`
186			`unsigned32 rdir_loc; /* root directory start */`
187			`unsigned16 rdir_entrs; /* files per root directory */`
188			`unsigned32 rdir_secs; /* sectors per root directory */`
189			`unsigned32 rdir_size; /* root directory size in bytes */`
190			`unsigned32 tot_secs; /* total count of sectors */`
191			`unsigned32 data_fsec; /* first data sector */`
192			`unsigned32 data_cls; /* count of data clusters */`
193			`unsigned32 rdir_cl; /* first cluster of the root directory */`
194			`unsigned16 info_sec; /* FSInfo Sector Structure location */`
195			`unsigned32 free_cls; /* last known free clusters count */`
196			`unsigned32 next_cl; /* next free cluster number */`
197			`unsigned8 mirror; /* mirroring enabla/disable */`
198			`unsigned32 afat_loc; /* active FAT location */`
199			`unsigned8 afat; /* the number of active FAT */`
200			`dev_t dev; /* device ID */`
201			`disk_device dd; / disk device (see libblock) */`
202			`void private_data; / reserved */`
203			`} fat_vol_t;`
204
205
206			`typedef struct fat_cache_s`
207			`{`
208			`unsigned32 blk_num;`
209			`rtems_boolean modified;`
210			`unsigned8 state;`
211			`bdbuf_buffer *buf;`
212			`} fat_cache_t;`
213
214			`/*`
215			`* This structure identifies the instance of the filesystem on the FAT`
216			`* ("fat-file") level.`
217			`*/`
218			`typedef struct fat_fs_info_s`
219			`{`
220			`fat_vol_t vol; /* volume descriptor */`
221			`Chain_Control vhash; / "vhash" of fat-file descriptors */`
222			`Chain_Control rhash; / "rhash" of fat-file descriptors */`
223			`char uino; / array of unique ino numbers */`
224			`unsigned32 index;`
225			`unsigned32 uino_pool_size; /* size */`
226			`unsigned32 uino_base;`
227			`fat_cache_t c; /* cache */`
228			`unsigned8 sec_buf; / just placeholder for anything */`
229			`} fat_fs_info_t;`
230
231			`/*`
232			`* if the name we looking for is file we store not only first data cluster`
233			`* number, but and cluster number and offset for directory entry for this`
234			`* name`
235			`*/`
236			`typedef struct fat_auxiliary_s`
237			`{`
238			`unsigned32 cln;`
239			`unsigned32 ofs;`
240			`} fat_auxiliary_t;`
241
242			`#define FAT_FAT_OFFSET(fat_type, cln) \`
243			`((fat_type) & FAT_FAT12 ? ((cln) + ((cln) >> 1)) : \`
244			`(fat_type) & FAT_FAT16 ? ((cln) << 1) : \`
245			`((cln) << 2))`
246
247			`#define FAT_CLUSTER_IS_ODD(n) ((n) & 0x0001)`
248
249			`#define FAT12_SHIFT 0x4 /* half of a byte */`
250
251			`/* initial size of array of unique ino */`
252			`#define FAT_UINO_POOL_INIT_SIZE 0x100`
253
254			`/* cache support */`
255			`#define FAT_CACHE_EMPTY 0x0`
256			`#define FAT_CACHE_ACTUAL 0x1`
257
258			`#define FAT_OP_TYPE_READ 0x1`
259			`#define FAT_OP_TYPE_GET 0x2`
260
261			`static inline unsigned32`
262			`fat_cluster_num_to_sector_num(`
263			`rtems_filesystem_mount_table_entry_t *mt_entry,`
264			`unsigned32 cln`
265			`)`
266			`{`
267			`register fat_fs_info_t *fs_info = mt_entry->fs_info;`
268
269			`if ( (cln == 0) && (fs_info->vol.type & (FAT_FAT12 \| FAT_FAT16)) )`
270			`return fs_info->vol.rdir_loc;`
271
272			`return (((cln - FAT_RSRVD_CLN) << fs_info->vol.spc_log2) +`
273			`fs_info->vol.data_fsec);`
274			`}`
275
276			`static inline unsigned32`
277			`fat_cluster_num_to_sector512_num(`
278			`rtems_filesystem_mount_table_entry_t *mt_entry,`
279			`unsigned32 cln`
280			`)`
281			`{`
282			`fat_fs_info_t *fs_info = mt_entry->fs_info;`
283
284			`if (cln == 1)`
285			`return 1;`
286
287			`return (fat_cluster_num_to_sector_num(mt_entry, cln) <<`
288			`fs_info->vol.sec_mul);`
289			`}`
290
291			`static inline int`
292			`fat_buf_access(fat_fs_info_t *fs_info, unsigned32 blk, int op_type,`
293			`bdbuf_buffer **buf)`
294			`{`
295			`rtems_status_code sc = RTEMS_SUCCESSFUL;`
296			`unsigned8 i;`
297			`rtems_boolean sec_of_fat;`
298
299
300			`if (fs_info->c.state == FAT_CACHE_EMPTY)`
301			`{`
302			`if (op_type == FAT_OP_TYPE_READ)`
303			`sc = rtems_bdbuf_read(fs_info->vol.dev, blk, &fs_info->c.buf);`
304			`else`
305			`sc = rtems_bdbuf_get(fs_info->vol.dev, blk, &fs_info->c.buf);`
306			`if (sc != RTEMS_SUCCESSFUL)`
307			`set_errno_and_return_minus_one(EIO);`
308			`fs_info->c.blk_num = blk;`
309			`fs_info->c.state = FAT_CACHE_ACTUAL;`
310			`}`
311
312			`sec_of_fat = ((fs_info->c.blk_num >= fs_info->vol.fat_loc) &&`
313			`(fs_info->c.blk_num < fs_info->vol.rdir_loc));`
314
315			`if (fs_info->c.blk_num != blk)`
316			`{`
317			`if (fs_info->c.modified)`
318			`{`
319			`if (sec_of_fat && !fs_info->vol.mirror)`
320			`memcpy(fs_info->sec_buf, fs_info->c.buf->buffer,`
321			`fs_info->vol.bps);`
322
323			`sc = rtems_bdbuf_release_modified(fs_info->c.buf);`
324			`if (sc != RTEMS_SUCCESSFUL)`
325			`set_errno_and_return_minus_one(EIO);`
326			`fs_info->c.modified = 0;`
327
328			`if (sec_of_fat && !fs_info->vol.mirror)`
329			`{`
330			`bdbuf_buffer *b;`
331
332			`for (i = 1; i < fs_info->vol.fats; i++)`
333			`{`
334			`sc = rtems_bdbuf_get(fs_info->vol.dev,`
335			`fs_info->c.blk_num +`
336			`fs_info->vol.fat_length * i,`
337			`&b);`
338			`if ( sc != RTEMS_SUCCESSFUL)`
339			`set_errno_and_return_minus_one(ENOMEM);`
340			`memcpy(b->buffer, fs_info->sec_buf, fs_info->vol.bps);`
341			`sc = rtems_bdbuf_release_modified(b);`
342			`if ( sc != RTEMS_SUCCESSFUL)`
343			`set_errno_and_return_minus_one(ENOMEM);`
344			`}`
345			`}`
346			`}`
347			`else`
348			`{`
349			`sc = rtems_bdbuf_release(fs_info->c.buf);`
350			`if (sc != RTEMS_SUCCESSFUL)`
351			`set_errno_and_return_minus_one(EIO);`
352
353			`}`
354			`if (op_type == FAT_OP_TYPE_READ)`
355			`sc = rtems_bdbuf_read(fs_info->vol.dev, blk, &fs_info->c.buf);`
356			`else`
357			`sc = rtems_bdbuf_get(fs_info->vol.dev, blk, &fs_info->c.buf);`
358			`if (sc != RTEMS_SUCCESSFUL)`
359			`set_errno_and_return_minus_one(EIO);`
360			`fs_info->c.blk_num = blk;`
361			`}`
362			`*buf = fs_info->c.buf;`
363			`return RC_OK;`
364			`}`
365
366
367			`static inline int`
368			`fat_buf_release(fat_fs_info_t *fs_info)`
369			`{`
370			`rtems_status_code sc = RTEMS_SUCCESSFUL;`
371			`unsigned8 i;`
372			`rtems_boolean sec_of_fat;`
373
374			`if (fs_info->c.state == FAT_CACHE_EMPTY)`
375			`return RC_OK;`
376
377			`sec_of_fat = ((fs_info->c.blk_num >= fs_info->vol.fat_loc) &&`
378			`(fs_info->c.blk_num < fs_info->vol.rdir_loc));`
379
380			`if (fs_info->c.modified)`
381			`{`
382			`if (sec_of_fat && !fs_info->vol.mirror)`
383			`memcpy(fs_info->sec_buf, fs_info->c.buf->buffer, fs_info->vol.bps);`
384
385			`sc = rtems_bdbuf_release_modified(fs_info->c.buf);`
386			`if (sc != RTEMS_SUCCESSFUL)`
387			`set_errno_and_return_minus_one(EIO);`
388			`fs_info->c.modified = 0;`
389
390			`if (sec_of_fat && !fs_info->vol.mirror)`
391			`{`
392			`bdbuf_buffer *b;`
393
394			`for (i = 1; i < fs_info->vol.fats; i++)`
395			`{`
396			`sc = rtems_bdbuf_get(fs_info->vol.dev,`
397			`fs_info->c.blk_num +`
398			`fs_info->vol.fat_length * i,`
399			`&b);`
400			`if ( sc != RTEMS_SUCCESSFUL)`
401			`set_errno_and_return_minus_one(ENOMEM);`
402			`memcpy(b->buffer, fs_info->sec_buf, fs_info->vol.bps);`
403			`sc = rtems_bdbuf_release_modified(b);`
404			`if ( sc != RTEMS_SUCCESSFUL)`
405			`set_errno_and_return_minus_one(ENOMEM);`
406			`}`
407			`}`
408			`}`
409			`else`
410			`{`
411			`sc = rtems_bdbuf_release(fs_info->c.buf);`
412			`if (sc != RTEMS_SUCCESSFUL)`
413			`set_errno_and_return_minus_one(EIO);`
414			`}`
415			`fs_info->c.state = FAT_CACHE_EMPTY;`
416			`return RC_OK;`
417			`}`
418
419			`static inline void`
420			`fat_buf_mark_modified(fat_fs_info_t *fs_info)`
421			`{`
422			`fs_info->c.modified = TRUE;`
423			`}`
424
425
426
427			`ssize_t`
428			`_fat_block_read(rtems_filesystem_mount_table_entry_t *mt_entry,`
429			`unsigned32 start,`
430			`unsigned32 offset,`
431			`unsigned32 count,`
432			`void *buff);`
433
434			`ssize_t`
435			`_fat_block_write(rtems_filesystem_mount_table_entry_t *mt_entry,`
436			`unsigned32 start,`
437			`unsigned32 offset,`
438			`unsigned32 count,`
439			`const void *buff);`
440
441			`ssize_t`
442			`fat_cluster_read(rtems_filesystem_mount_table_entry_t *mt_entry,`
443			`unsigned32 cln,`
444			`void *buff);`
445
446			`ssize_t`
447			`fat_cluster_write(rtems_filesystem_mount_table_entry_t *mt_entry,`
448			`unsigned32 cln,`
449			`const void *buff);`
450
451			`int`
452			`fat_init_volume_info(rtems_filesystem_mount_table_entry_t *mt_entry);`
453
454			`int`
455			`fat_init_clusters_chain(rtems_filesystem_mount_table_entry_t *mt_entry,`
456			`unsigned32 start_cln);`
457
458			`unsigned32`
459			`fat_cluster_num_to_sector_num(rtems_filesystem_mount_table_entry_t *mt_entry,`
460			`unsigned32 cln);`
461
462			`int`
463			`fat_shutdown_drive(rtems_filesystem_mount_table_entry_t *mt_entry);`
464
465
466			`unsigned32`
467			`fat_get_unique_ino(rtems_filesystem_mount_table_entry_t *mt_entry);`
468
469			`rtems_boolean`
470			`fat_ino_is_unique(rtems_filesystem_mount_table_entry_t *mt_entry,`
471			`unsigned32 ino);`
472
473			`void`
474			`fat_free_unique_ino(rtems_filesystem_mount_table_entry_t *mt_entry,`
475			`unsigned32 ino);`
476
477			`int`
478			`fat_fat32_update_fsinfo_sector(`
479			`rtems_filesystem_mount_table_entry_t *mt_entry,`
480			`unsigned32 free_count,`
481			`unsigned32 next_free`
482			`);`
483
484			`#ifdef __cplusplus`
485			`}`
486			`#endif`
487
488			`#endif /* __DOSFS_FAT_H__ */`