msdos.h

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#ifndef MTOOLS_MSDOS_H
#define MTOOLS_MSDOS_H

/*
 * msdos common header file
 */

#define MAX_SECTOR      8192            /* largest sector size */
#define MDIR_SIZE       32              /* MSDOS directory entry size in bytes*/
#define MAX_CLUSTER     8192            /* largest cluster size */
#define MAX_PATH        128             /* largest MSDOS path length */
#define MAX_DIR_SECS    64              /* largest directory (in sectors) */
#define MSECTOR_SIZE    msector_size

#define NEW             1
#define OLD             0

#define _WORD(x) ((unsigned char)(x)[0] + (((unsigned char)(x)[1]) << 8))
#define _DWORD(x) (_WORD(x) + (_WORD((x)+2) << 16))

#define DELMARK ((char) 0xe5)

struct directory {
        char name[8];                   /*  0 file name */
        char ext[3];                    /*  8 file extension */
        unsigned char attr;             /* 11 attribute byte */
        unsigned char Case;             /* 12 case of short filename */
        unsigned char ctime_ms;         /* 13 creation time, milliseconds (?) */
        unsigned char ctime[2];         /* 14 creation time */
        unsigned char cdate[2];         /* 16 creation date */
        unsigned char adate[2];         /* 18 last access date */
        unsigned char startHi[2];       /* 20 start cluster, Hi */
        unsigned char time[2];          /* 22 time stamp */
        unsigned char date[2];          /* 24 date stamp */
        unsigned char start[2];         /* 26 starting cluster number */
        unsigned char size[4];          /* 28 size of the file */
};

#define EXTCASE 0x10
#define BASECASE 0x8

#define MAX32 0xffffffff
#define MAX_SIZE 0x7fffffff

#define FILE_SIZE(dir)  (_DWORD((dir)->size))
#define START(dir) (_WORD((dir)->start))
#define STARTHI(dir) (_WORD((dir)->startHi))

/* ASSUMPTION: long is at least 32 bits */
UNUSED(static inline void set_dword(unsigned char *data, unsigned long value))
{
        data[3] = (value >> 24) & 0xff;
        data[2] = (value >> 16) & 0xff;
        data[1] = (value >>  8) & 0xff;
        data[0] = (value >>  0) & 0xff;
}


/* ASSUMPTION: short is at least 16 bits */
UNUSED(static inline void set_word(unsigned char *data, unsigned short value))
{
        data[1] = (value >>  8) & 0xff;
        data[0] = (value >>  0) & 0xff;
}


/*
 *          hi byte     |    low byte
 *      |7|6|5|4|3|2|1|0|7|6|5|4|3|2|1|0|
 *  | | | | | | | | | | | | | | | | |
 *  \   7 bits    /\4 bits/\ 5 bits /
 *     year +80     month     day
 */
#define DOS_YEAR(dir) (((dir)->date[1] >> 1) + 1980)
#define DOS_MONTH(dir) (((((dir)->date[1]&0x1) << 3) + ((dir)->date[0] >> 5)))
#define DOS_DAY(dir) ((dir)->date[0] & 0x1f)

/*
 *          hi byte     |    low byte
 *      |7|6|5|4|3|2|1|0|7|6|5|4|3|2|1|0|
 *      | | | | | | | | | | | | | | | | |
 *      \  5 bits /\  6 bits  /\ 5 bits /
 *         hour      minutes     sec*2
 */
#define DOS_HOUR(dir) ((dir)->time[1] >> 3)
#define DOS_MINUTE(dir) (((((dir)->time[1]&0x7) << 3) + ((dir)->time[0] >> 5)))
#define DOS_SEC(dir) (((dir)->time[0] & 0x1f) * 2)


typedef struct InfoSector_t {
        unsigned char signature1[4];
        unsigned char filler1[0x1e0];
        unsigned char signature2[4];
        unsigned char count[4];
        unsigned char pos[4];
        unsigned char filler2[14];
        unsigned char signature3[2];
} InfoSector_t;

#define INFOSECT_SIGNATURE1 0x41615252
#define INFOSECT_SIGNATURE2 0x61417272


typedef struct label_blk_t {
        unsigned char physdrive;        /* 36 physical drive ? */
        unsigned char reserved;         /* 37 reserved */
        unsigned char dos4;             /* 38 dos > 4.0 diskette */
        unsigned char serial[4];        /* 39 serial number */
        char label[11];                 /* 43 disk label */
        char fat_type[8];               /* 54 FAT type */
} label_blk_t;

/* FAT32 specific info in the bootsector */
typedef struct fat32_t {
        unsigned char bigFat[4];        /* 36 nb of sectors per FAT */
        unsigned char extFlags[2];      /* 40 extension flags */
        unsigned char fsVersion[2];     /* 42 ? */
        unsigned char rootCluster[4];   /* 44 start cluster of root dir */
        unsigned char infoSector[2];    /* 48 changeable global info */
        unsigned char backupBoot[2];    /* 50 back up boot sector */
        unsigned char reserved[6];      /* 52 ? */
        unsigned char reserved2[6];     /* 52 ? */
        struct label_blk_t labelBlock;
} fat32; /* ends at 58 */

typedef struct oldboot_t {
        struct label_blk_t labelBlock;
        unsigned char res_2m;           /* 62 reserved by 2M */
        unsigned char CheckSum;         /* 63 2M checksum (not used) */
        unsigned char fmt_2mf;          /* 64 2MF format version */
        unsigned char wt;               /* 65 1 if write track after format */
        unsigned char rate_0;           /* 66 data transfer rate on track 0 */
        unsigned char rate_any;         /* 67 data transfer rate on track<>0 */
        unsigned char BootP[2];         /* 68 offset to boot program */
        unsigned char Infp0[2];         /* 70 T1: information for track 0 */
        unsigned char InfpX[2];         /* 72 T2: information for track<>0 */
        unsigned char InfTm[2];         /* 74 T3: track sectors size table */
        unsigned char DateF[2];         /* 76 Format date */
        unsigned char TimeF[2];         /* 78 Format time */
        unsigned char junk[1024 - 80];  /* 80 remaining data */
} oldboot_t;

struct bootsector {
        unsigned char jump[3];          /* 0  Jump to boot code */
        char banner[8] PACKED;          /* 3  OEM name & version */
        unsigned char secsiz[2] PACKED; /* 11 Bytes per sector hopefully 512 */
        unsigned char clsiz;            /* 13 Cluster size in sectors */
        unsigned char nrsvsect[2];      /* 14 Number of reserved (boot) sectors */
        unsigned char nfat;             /* 16 Number of FAT tables hopefully 2 */
        unsigned char dirents[2] PACKED;/* 17 Number of directory slots */
        unsigned char psect[2] PACKED;  /* 19 Total sectors on disk */
        unsigned char descr;            /* 21 Media descriptor=first byte of FAT */
        unsigned char fatlen[2];        /* 22 Sectors in FAT */
        unsigned char nsect[2];         /* 24 Sectors/track */
        unsigned char nheads[2];        /* 26 Heads */
        unsigned char nhs[4];           /* 28 number of hidden sectors */
        unsigned char bigsect[4];       /* 32 big total sectors */

        union {
                struct fat32_t fat32;
                struct oldboot_t old;
        } ext;
};

#define CHAR(x) (boot->x[0])
#define WORD(x) (_WORD(boot->x))
#define DWORD(x) (_DWORD(boot->x))
#define OFFSET(x) (((char *) (boot->x)) - ((char *)(boot->jump)))


extern struct OldDos_t {
        int tracks;
        int sectors;
        int heads;
        
        int dir_len;
        int cluster_size;
        int fat_len;

        int media;
} old_dos[];

#define FAT12 4085 /* max. number of clusters described by a 12 bit FAT */
#define FAT16 65525

#define ATTR_ARCHIVE 0x20
#define ATTR_DIR 0x10
#define ATTR_LABEL 0x8
#define ATTR_SYSTEM 0x4
#define ATTR_HIDDEN 0x2
#define ATTR_READONLY 0x1

#define HAS_BIT(entry,x) ((entry)->dir.attr & (x))

#define IS_ARCHIVE(entry) (HAS_BIT((entry),ATTR_ARCHIVE))
#define IS_DIR(entry) (HAS_BIT((entry),ATTR_DIR))
#define IS_LABEL(entry) (HAS_BIT((entry),ATTR_LABEL))
#define IS_SYSTEM(entry) (HAS_BIT((entry),ATTR_SYSTEM))
#define IS_HIDDEN(entry) (HAS_BIT((entry),ATTR_HIDDEN))
#define IS_READONLY(entry) (HAS_BIT((entry),ATTR_READONLY))


#define MAX_SECT_PER_CLUSTER 64
/* Experimentally, it turns out that DOS only accepts cluster sizes
 * which are powers of two, and less than 128 sectors (else it gets a
 * divide overflow) */


#define FAT_SIZE(bits, sec_siz, clusters) \
        ((((clusters)+2) * ((bits)/4) - 1) / 2 / (sec_siz) + 1)

#define NEEDED_FAT_SIZE(x) FAT_SIZE((x)->fat_bits, (x)->sector_size, \
                                    (x)->num_clus)

/* disk size taken by FAT and clusters */
#define DISK_SIZE(bits, sec_siz, clusters, n, cluster_size) \
        ((n) * FAT_SIZE(bits, sec_siz, clusters) + \
         (clusters) * (cluster_size))

#define TOTAL_DISK_SIZE(bits, sec_siz, clusters, n, cluster_size) \
        (DISK_SIZE(bits, sec_siz, clusters, n, cluster_size) + 2)
/* approx. total disk size: assume 1 boot sector and one directory sector */

extern const char *mversion;
extern const char *mdate;

extern char *Version;
extern char *Date;


int init(char drive, int mode);

#define MT_READ 1
#define MT_WRITE 2

#endif

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