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#include "monitor.h"
#ifndef MAXTRK
#define MAXTRK 18
#endif
int disk_drive = 0;
int disk_spt = 7;
int disk_heads = 0;
int disk_cyls = 0;
long disk_partition_offset = 0;
static long bad_start = -1;
static long buf_start = -1;
static int buf_sec = 0;
static int buf_len = 0;
static char buffer[MAXTRK*512]; /* WARNING: This must be DMAable */
void reset_disk()
{
disk_spt = 7; /* Defaults for reading floppy boot area. */
disk_heads = 0;
disk_cyls = 0;
bad_start = -1;
disk_partition_offset = 0;
#ifdef __STANDALONE__
if( disk_drive == __argr.h.dl && __argr.x.si >= 9 && __argr.x.si <= 63 )
{
disk_spt = __argr.x.si;
disk_heads = 2;
disk_cyls = 80;
}
if( disk_drive & 0x80 )
{
/* Hard disk, get parameters from bios */
long dpt;
int v;
if( disk_drive == __argr.h.dl )
disk_partition_offset = __argr.x.cx + ((long)__argr.h.dh<<16);
dpt = _bios_get_dpt(disk_drive);
v = ((dpt>>16) & 0xFF);
if( v != 0xFF && v > (disk_drive&0x7F) )
{
disk_spt = (dpt & 0x3F); /* Max sector number 1-63 */
if( disk_spt == 0 ) disk_spt = 64; /* 1-64 ? */
disk_heads = ((dpt>>24) & 0xFF) + 1; /* Head count 1-256 */
disk_cyls = ((dpt>>8) & 0xFF) + ((dpt<<2) & 0x300) + 1;
/* Cyls count, unchecked, only needs != 0, if AMI 386 bios can be
* upto 4096 cylinder, otherwise BIOS limit is 1024 cyl.
*/
}
}
#endif
}
char * read_lsector(sectno)
long sectno;
{
int tries;
int rv = 0;
int phy_s = 1;
int phy_h = 0;
int phy_c = 0;
long bstart;
if( sectno == 0 || disk_heads == 0 ) reset_disk();
if( disk_partition_offset > 0 ) sectno += disk_partition_offset;
if( disk_spt < 1 || disk_heads < 1 )
phy_s = sectno;
else
{
phy_s = sectno%disk_spt;
phy_h = sectno/disk_spt%disk_heads;
phy_c = sectno/disk_spt/disk_heads;
bstart = (long)phy_c*disk_heads+phy_h;
if (disk_spt > MAXTRK) {
bstart = bstart * (disk_spt+MAXTRK-1)/MAXTRK;
buf_sec = phy_s/MAXTRK;
bstart = bstart + buf_sec;
buf_sec *= MAXTRK;
if (disk_spt > buf_sec+MAXTRK) buf_len = MAXTRK;
else buf_len = disk_spt-buf_sec;
} else {
buf_sec = 0;
buf_len = disk_spt;
}
if( bstart != buf_start && bstart != bad_start && buf_len > 1 )
{
rv = _bios_disk_read(disk_drive,phy_c,phy_h,buf_sec+1,buf_len,buffer);
if( rv == 0 )
buf_start = bstart;
else {
bad_start = bstart;
buf_start = -1;
}
#ifdef DEBUG
printf("Track read %d,%d,%d,%d,%d,%d -> %d\n",
disk_drive,phy_c,phy_h,buf_sec+1,buf_len,buffer, rv);
#endif
}
if( bstart == buf_start )
return buffer + (phy_s-buf_sec) * 512;
}
tries = 6;
do
{
if( rv && tries<0) {
int v;
printf("Disk error 0x%02x %d:%d:%d:%d[%2d] -> 0x%04x[]\n",
rv, disk_drive, phy_c, phy_h, phy_s+1, 1, buffer);
printf("Retry ?"); v = (getch()&0x7F); printf("\n");
if (v == 3 || v == 27 || v == 'n' || v == 'N')
return 0;
tries = 6;
}
if (tries == 3) _bios_disk_reset(disk_drive);
rv = _bios_disk_read(disk_drive, phy_c, phy_h, phy_s+1, 1, buffer);
tries--;
}
while(rv);
#ifdef DEBUG
printf("Sector read %d,%d,%d,%d,%d,%d -> %d\n",
disk_drive,phy_c,phy_h,phy_s+1,1,buffer, rv);
#endif
if(rv) return 0; else return buffer;
}
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