/*******************************************************************************
* bool floppy_block_write(unsigned int block, void *blockbuff,
* unsigned int nosectors)
*
* This writes the contents of 'blockbuff' onto a floppy disk, starting at 'block'
* and going for 'nosectors'
*
* Parameters:
* 1) int block
* The starting sector to write to
* 2) unsigned char *blockbuff
* The buffer to read from when writing
*
* Date: December 31, 2004
* *****************************************************************************/
bool floppy_block_write(unsigned int block, void *blockbuff, unsigned int nosectors)
{
return floppy_rw(block, blockbuff, false, nosectors);
}
/*******************************************************************************
* bool floppy_block_read(unsigned int block, void *blockbuff,
* unsigned int nosectors)
*
* This reads data from a floppy disk starting at 'block' and reads 'nosectors'
* number of blocks.
*
* Parameters:
* 1) int block
* The starting sector to read
* 2) unsigned char *blockbuff
* The buffer to be read into
* 3) unsigned long nosectors
* How many sectors do we want to read in?
*
* Date: December 31, 2004
* *****************************************************************************/
bool floppy_block_read(unsigned int block, void *blockbuff, unsigned int nosectors)
{
return floppy_rw(block, blockbuff, true, nosectors);
}
/* Write ONE sector */
int floppy_write(int sector, void * buf)
{
return floppy_rw(sector, buf, FD_WRITE);
}
/*******************************************************************************
* bool floppy_rw(int block, unsigned char *blockbuff,
* unsigned char read, unsigned long nosectors)
*
* Since the read and write to a floppy disk is not that much different, most of
* the code is the same. The only difference is dependent on what the 'read'
* variable is set as.
*
* Parameters:
* 1) int block
* This is the block that we want to read.
* 2) unsigned char *blockbuff
* This is the buffer that we want it read into or written out to. The size
* of this buffer should be 512 * nosectors, as each sector read in is 512
* bytes
* 3) unsigned char read
* Are we going to read or write to this block.
* 4) unsigned long nosectors
* The number of sectors that we want to be read in.
*
* Return value:
* This returns where or not the read/write was successfull.
*
* Date: December 31, 2004
* *****************************************************************************/
bool floppy_rw(int block, unsigned char *blockbuff, unsigned char read, unsigned long nosectors)
{
int head;
int track;
int sector;
int tries;
int copycount=0;
unsigned char *p_track_buffer = (unsigned char*)floppy_dma_address;
unsigned char *p_block_buffer = blockbuff;
///convert logical address into physical address
floppy_block2hts(block , &head, &track, §or);
///start the floppy motor
floppy_motor_start();
if (!read && blockbuff)
///copy data from the data buffer into the track buffer
for (copycount=0; copycount<(nosectors*512); copycount++)
*(p_track_buffer++) = *(p_block_buffer++);
for (tries = 0; tries < 3; tries++)
{
///check for disk change
if (inportb(FDC_DIR) & 0x80)
{
floppy_dchange = true;
floppy_seek(1);
floppy_recalibrate();
floppy_motor_stop();
ERROR_MSG(("FDC: Disk change detected. Trying again."));
return floppy_rw(block, blockbuff, read, nosectors);
}
///move head to the right track
if (!floppy_seek(track))
{
floppy_motor_stop();
ERROR_MSG(("FDC: Seek error"));
return false;
}
///program data rate (500Kb/s)
outportb(FDC_CCR, 0);
///send command
if (read)
{
dma_xfer(2, (unsigned long)floppy_dma_address, nosectors*512, false);
floppy_sendbyte(CMD_READ);
} else {
dma_xfer(2, (unsigned long)floppy_dma_address, nosectors*512, true);
floppy_sendbyte(CMD_WRITE);
}
floppy_sendbyte(head << 2);
floppy_sendbyte(track);
floppy_sendbyte(head);
floppy_sendbyte(sector);
floppy_sendbyte(2);
floppy_sendbyte(floppy_geometry.spt);
if (floppy_geometry.spt == DG144_SPT)
floppy_sendbyte(DG144_GAP3RW);
else
floppy_sendbyte(DG168_GAP3RW);
floppy_sendbyte(0xff);
///wait for commmand completion
if (!floppy_wait(true)) {
ERROR_MSG(("Timed out, trying operation again after reset"));
floppy_reset();
return floppy_rw(block, blockbuff, read, nosectors);
}
///let's see if the transfer worked
if ((floppy_status[0] & 0xC0) == 0) break;
///it didn't work. try again
floppy_recalibrate();
}
floppy_motor_stop();
if (read && blockbuff)
{
///copy data from track buffer into data buffer
p_block_buffer = blockbuff;
p_track_buffer = (unsigned char *)floppy_dma_address;
for (copycount = 0; copycount <(nosectors*512); copycount++)
{
*p_block_buffer = *p_track_buffer;
p_block_buffer++;
p_track_buffer++;
}
}
return (tries != 3);
}
/* Read ONE sector */
int floppy_read(int sector, void * buf)
{
return floppy_rw(sector, buf, FD_READ);
}
