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#include "monitor.h"
#ifdef MINI_BUF
#define BUFFER_FAT
#endif
#define DOS_SECT(P) get_uint(P,0x0B)
#define DOS_CLUST(P) get_byte(P,0x0D)
#define DOS_RESV(P) get_uint(P,0x0E)
#define DOS_NFAT(P) get_byte(P,0x10)
#define DOS_NROOT(P) get_uint(P,0x11)
#define DOS_MAXSECT(P) get_uint(P,0x13)
#define DOS_MEDIA(P) get_byte(P,0x15)
#define DOS_FATLEN(P) get_uint(P,0x16)
#define DOS_SPT(P) get_uint(P,0x18)
#define DOS_HEADS(P) get_uint(P,0x1A)
#define DOS_HIDDEN(P) get_long(P,0x1C)
#define DOS4_MAXSECT(P) get_long(P,0x20)
#define DOS4_PHY_DRIVE(P) get_byte(P,0x24)
#define DOS4_SERIAL(P) get_long(P,0x27)
#define DOS4_FATTYPE(P) get_uint(P,0x39)
/* These assume alignment is not a problem */
#define get_byte(P,Off) *((unsigned char*)((char*)(P)+(Off)))
#define get_uint(P,Off) *((unsigned short*)((char*)(P)+(Off)))
#define get_long(P,Off) *((long*)((char*)(P)+(Off)))
typedef long Tsect;
static int read_bootblock();
static int dir_nentry, dir_sect;
static Tsect dos_clust0, dos_spc;
static int dos_fatpos, dos_fatlen, dos_fattype;
static int last_serial = 0;
#ifdef BUFFER_FAT
static char * fat_buf = 0;
int use_fatbuf = 0;
#endif
static
struct filestatus {
char fname[12];
unsigned short first_cluster;
unsigned short cur_cluster;
unsigned short sector_no; /* Max filesize = 32M */
long file_length;
}
cur_file = { "", 0, 0, 0 };
dos_open_file(fname)
char * fname;
{
char conv_name[12];
char *s, *d;
int i;
int dodir = 0;
/* Get the superblock */
if( read_bootblock() < 0 ) return -1;
if(strcmp(fname, ".") == 0)
dodir = 1;
else
{
/* Convert the name to MSDOS directory format */
strcpy(conv_name, " ");
for(s=fname, d=conv_name; *s && *d && *s != '.' && *s != ' '; s++)
{
if( islower(*s) ) *d++ = toupper(*s);
else *d++ = *s;
}
while( *s && *s != '.' ) s++;
strcpy(d=(conv_name+8), " ");
if( *s == '.' )
{
for(s++; *s && *d; s++)
{
if( islower(*s) ) *d++ = toupper(*s);
else *d++ = *s;
}
}
/* Already opened ? Then just rewind it */
if( cur_file.first_cluster && strcmp(cur_file.fname, conv_name) == 0 )
return dos_rewind_file();
}
memset(&cur_file, '\0', sizeof(cur_file));
#ifdef BUFFER_FAT
if( !dodir && dos_fattype == 12 )
{
/* Read in and buffer the FAT */
if( fat_buf ) free(fat_buf);
fat_buf = malloc(dos_fatlen * 512);
if( fat_buf == 0 )
use_fatbuf = 0;
else
{
use_fatbuf = 1;
for(i=0; i<dos_fatlen; i++)
{
s = read_sector(dos_fatpos+i);
if(s == 0)
{
use_fatbuf = 0;
free(fat_buf);
fat_buf = 0;
}
memcpy(fat_buf+i*512, s, 512);
}
}
}
else
use_fatbuf = 0;
#endif
/* Scan the root directory for the file */
for(i=0; i<dir_nentry; i++)
{
s = read_sector(dir_sect+i/16);
if( s == 0 ) return -1;
d = s + (i%16)*32;
if( dodir )
{
#ifdef NOCOMMAND
break;
#else
int dtime = 0;
char lbuf[90];
*lbuf = 0;
if( *d > ' ' && *d <= '~' ) switch(d[11]&0x18)
{
case 0:
printf("%-8.8s %-3.3s %10ld", d, d+8, get_long(d,28));
dtime=1;
break;
case 0x10:
printf("%-8.8s %-3.3s <DIR> ", d, d+8);
dtime=1;
break;
case 8:
if( (d[11] & 7) == 0 )
{
printf("%-11.11s <LBL> ", d);
dtime=1;
}
break;
}
if( dtime )
printf(dtime, " %02d/%02d/%04d %02d:%02d\n",
(get_uint(d,24)&0x1F),
((get_uint(d,24)>>5)&0xF),
((get_uint(d,24)>>9)&0x7F)+1980,
((get_uint(d,22)>>11)&0x1F),
((get_uint(d,22)>>5)&0x3F)
);
if( more_strn(lbuf, sizeof(lbuf)) < 0 ) break;
#endif
}
else if( memcmp(d, conv_name, 11) == 0 && (d[11]&0x18) == 0 )
{ /* Name matches and is normal file */
strcpy(cur_file.fname, conv_name);
cur_file.first_cluster = get_uint(d,26);
cur_file.file_length = get_long(d,28);
cur_file.cur_cluster = cur_file.first_cluster;
cur_file.sector_no = 0;
#ifdef DEBUG
fprintf(stderr, "Opened first cluster %d, len %ld\n",
cur_file.first_cluster,
cur_file.file_length
);
#endif
return 0;
}
}
return -1;
}
dos_rewind_file()
{
/* Is there an opened file ? */
if( cur_file.fname[0] == 0 ) return -1;
cur_file.sector_no = 0;
cur_file.cur_cluster = cur_file.first_cluster;
return 0;
}
dos_close_file()
{
#ifdef BUFFER_FAT
if( fat_buf ) free(fat_buf);
fat_buf = 0;
#endif
memset(&cur_file, '\0', sizeof(cur_file));
reset_disk();
return 0;
}
long
dos_file_length()
{
/* Is there an opened file ? */
if( cur_file.fname[0] == 0 ) return -1;
return cur_file.file_length;
}
dos_read_block(buffer)
char * buffer;
{
int s;
char * ptr;
/* Is there an opened file ? */
if( cur_file.fname[0] == 0 )
{
#ifdef DEBUG
fprintf(stderr, "File is not currently open!\n");
#endif
return -1;
}
/* Are we before the EOF ? */
if( ( dos_fattype == 12 && cur_file.cur_cluster >= 0xFF0 ) ||
( dos_fattype == 16 && (cur_file.cur_cluster&0xFFF0) == 0xFFF0 ) ||
cur_file.cur_cluster < 2 )
{
#ifdef DEBUG
fprintf(stderr, "Hit end of file; cluster 0x%03x\n",
cur_file.cur_cluster);
#endif
return -1;
}
for(s=0; s<2; s++)
{
Tsect sectno;
if( ( dos_fattype == 12 && cur_file.cur_cluster >= 0xFF0 ) ||
( dos_fattype == 16 && (cur_file.cur_cluster&0xFFF0) == 0xFFF0 ) ||
cur_file.cur_cluster < 2 )
{
memset(buffer, '\0', 512);
buffer += 512;
continue;
}
sectno = dos_clust0
+ cur_file.cur_cluster * dos_spc
+ cur_file.sector_no % dos_spc;
ptr = read_sector(sectno);
if( ptr == 0 ) return -1;
memcpy(buffer, ptr, 512);
cur_file.sector_no++;
if( cur_file.sector_no % dos_spc == 0 )
{
if( dos_fattype == 12 )
{
int odd = (cur_file.cur_cluster&1);
unsigned int val, val2;
val = cur_file.cur_cluster + (cur_file.cur_cluster>>1);
#ifdef BUFFER_FAT
if( use_fatbuf )
val2 = get_uint(fat_buf, val);
else
#endif
{
ptr = read_sector(dos_fatpos+(val/512));
if( ptr == 0 ) return -1;
if( val%512 == 511 )
{
val2 = (ptr[511]&0xFF);
ptr = read_sector(dos_fatpos+(val/512)+1);
if( ptr == 0 ) return -1;
val2 |= (ptr[0]<<8);
}
else
val2 = get_uint(ptr, (val%512));
}
if( odd ) val2>>=4;
val2 &= 0xFFF;
cur_file.cur_cluster = val2;
}
else
{
ptr = read_sector(dos_fatpos+(cur_file.cur_cluster/256));
if( ptr == 0 ) return -1;
cur_file.cur_cluster = get_uint(ptr, (cur_file.cur_cluster%256*2));
}
}
buffer += 512;
}
return 0;
}
static int read_bootblock()
{
char * sptr;
int rv, media_byte = 0;
sptr = read_sector(1);
if( sptr == 0 ) return -1;
media_byte = *(unsigned char*)sptr;
/* Valid media byte ? */
if( (media_byte & 0xF0) != 0xF0 ) return -1;
sptr = read_sector(0);
if( sptr == 0 ) return -1;
if( DOS_MEDIA(sptr) != media_byte ) return -1;
if( DOS_SPT(sptr) > 63 ) return -1;
if( DOS_SECT(sptr) != 512 ) return -1;
if( last_serial != DOS4_SERIAL(sptr) ) dos_close_file();
last_serial = DOS4_SERIAL(sptr);
/* Collect important data */
dir_sect = DOS_RESV(sptr) + DOS_NFAT(sptr)*DOS_FATLEN(sptr);
dir_nentry = DOS_NROOT(sptr);
dos_fatpos = DOS_RESV(sptr);
dos_fatlen = DOS_FATLEN(sptr);
dos_spc = DOS_CLUST(sptr);
dos_fattype = DOS4_FATTYPE(sptr);
switch(dos_fattype)
{
case '1'+'6'*256: dos_fattype = 16; break;
case '1'+'2'*256:
default: dos_fattype = 12; break;
}
if( dos_spc < 1 ) dos_spc = 1;
dos_clust0 = dir_sect + (dir_nentry+15)/16 - 2*dos_spc;
if( disk_cyls == 0 )
{
disk_spt = DOS_SPT(sptr);
disk_heads = DOS_HEADS(sptr);
}
return 0;
}
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