hw_disk.c

这个是LINUX下的GDB调度工具的源码

  }
  return 0;
}





static unsigned
hw_disk_io_read_buffer(device *me,
		       void *dest,
		       int space,
		       unsigned_word addr,
		       unsigned nr_bytes,
		       cpu *processor,
		       unsigned_word cia)
{
  hw_disk_device *disk = device_data(me);
  unsigned nr_bytes_read;
  if (space != 0)
    device_error(me, "read - extended disk addressing unimplemented");
  if (nr_bytes == 0)
    nr_bytes_read = 0;
  else if (fseek(disk->image, addr, SEEK_SET) < 0)
    nr_bytes_read = 0;
  else if (fread(dest, nr_bytes, 1, disk->image) != 1)
    nr_bytes_read = 0;
  else
    nr_bytes_read = nr_bytes;
  DTRACE(disk, ("io-read - address 0x%lx, nr-bytes-read %d, requested %d\n",
                (unsigned long) addr, (int)nr_bytes_read, (int)nr_bytes));
  return nr_bytes_read;
}


static unsigned
hw_disk_io_write_buffer(device *me,
			const void *source,
			int space,
			unsigned_word addr,
			unsigned nr_bytes,
			cpu *processor,
			unsigned_word cia)
{
  hw_disk_device *disk = device_data(me);
  unsigned nr_bytes_written;
  if (space != 0)
    device_error(me, "write - extended disk addressing unimplemented");
  if (disk->read_only)
    nr_bytes_written = 0;
  else if (nr_bytes == 0)
    nr_bytes_written = 0;
  else if (fseek(disk->image, addr, SEEK_SET) < 0)
    nr_bytes_written = 0;
  else if (fwrite(source, nr_bytes, 1, disk->image) != 1)
    nr_bytes_written = 0;
  else
    nr_bytes_written = nr_bytes;
  DTRACE(disk, ("io-write - address 0x%lx, nr-bytes-written %d, requested %d\n",
                (unsigned long) addr, (int)nr_bytes_written, (int)nr_bytes));
  return nr_bytes_written;
}


/* instances of the hw_disk device */

static void
hw_disk_instance_delete(device_instance *instance)
{
  hw_disk_instance *data = device_instance_data(instance);
  DITRACE(disk, ("delete - instance=%ld\n",
		 (unsigned long)device_instance_to_external(instance)));
  zfree(data);
}

static int
hw_disk_instance_read(device_instance *instance,
		      void *buf,
		      unsigned_word len)
{
  hw_disk_instance *data = device_instance_data(instance);
  DITRACE(disk, ("read - instance=%ld len=%ld\n",
		 (unsigned long)device_instance_to_external(instance),
		 (long)len));
  if ((data->pos + len) < data->pos)
    return -1; /* overflow */
  if (fseek(data->disk->image, data->pos, SEEK_SET) < 0)
    return -1;
  if (fread(buf, len, 1, data->disk->image) != 1)
    return -1;
  data->pos = ftell(data->disk->image);
  return len;
}

static int
hw_disk_instance_write(device_instance *instance,
		       const void *buf,
		       unsigned_word len)
{
  hw_disk_instance *data = device_instance_data(instance);
  DITRACE(disk, ("write - instance=%ld len=%ld\n",
		 (unsigned long)device_instance_to_external(instance),
		 (long)len));
  if ((data->pos + len) < data->pos)
    return -1; /* overflow */
  if (data->disk->read_only)
    return -1;
  if (fseek(data->disk->image, data->pos, SEEK_SET) < 0)
    return -1;
  if (fwrite(buf, len, 1, data->disk->image) != 1)
    return -1;
  data->pos = ftell(data->disk->image);
  return len;
}

static int
hw_disk_instance_seek(device_instance *instance,
		      unsigned_word pos_hi,
		      unsigned_word pos_lo)
{
  hw_disk_instance *data = device_instance_data(instance);
  if (pos_hi != 0)
    device_error(device_instance_device(instance),
		 "seek - extended addressing unimplemented");
  DITRACE(disk, ("seek - instance=%ld pos_hi=%ld pos_lo=%ld\n",
		 (unsigned long)device_instance_to_external(instance),
		 (long)pos_hi, (long)pos_lo));
  data->pos = pos_lo;
  return 0;
}

static int
hw_disk_max_transfer(device_instance *instance,
		     int n_stack_args,
		     unsigned32 stack_args[/*n_stack_args*/],
		     int n_stack_returns,
		     unsigned32 stack_returns[/*n_stack_returns*/])
{
  device *me = device_instance_device(instance);
  if ((n_stack_args != 0)
      || (n_stack_returns != 1)) {
    device_error(me, "Incorrect number of arguments for max-transfer method\n");
    return -1;
  }
  else {
    unsigned_cell max_transfer;
    if (device_find_property(me, "max-transfer"))
      max_transfer = device_find_integer_property(me, "max-transfer");
    else
      max_transfer = 512;
    DITRACE(disk, ("max-transfer - instance=%ld max-transfer=%ld\n",
		   (unsigned long)device_instance_to_external(instance),
		   (long int)max_transfer));
    stack_returns[0] = max_transfer;
    return 0;
  }
}

static int
hw_disk_block_size(device_instance *instance,
		   int n_stack_args,
		   unsigned32 stack_args[/*n_stack_args*/],
		   int n_stack_returns,
		   unsigned32 stack_returns[/*n_stack_returns*/])
{
  device *me = device_instance_device(instance);
  if ((n_stack_args != 0)
      || (n_stack_returns != 1)) {
    device_error(me, "Incorrect number of arguments for block-size method\n");
    return -1;
  }
  else {
    unsigned_cell block_size;
    if (device_find_property(me, "block-size"))
      block_size = device_find_integer_property(me, "block-size");
    else
      block_size = 512;
    DITRACE(disk, ("block-size - instance=%ld block-size=%ld\n",
		   (unsigned long)device_instance_to_external(instance),
		   (long int)block_size));
    stack_returns[0] = block_size;
    return 0;
  }
}

static int
hw_disk_nr_blocks(device_instance *instance,
		  int n_stack_args,
		  unsigned32 stack_args[/*n_stack_args*/],
		  int n_stack_returns,
		  unsigned32 stack_returns[/*n_stack_returns*/])
{
  device *me = device_instance_device(instance);
  if ((n_stack_args != 0)
      || (n_stack_returns != 1)) {
    device_error(me, "Incorrect number of arguments for block-size method\n");
    return -1;
  }
  else {
    unsigned_word nr_blocks;
    if (device_find_property(me, "#blocks"))
      nr_blocks = device_find_integer_property(me, "#blocks");
    else
      nr_blocks = -1;
    DITRACE(disk, ("#blocks - instance=%ld #blocks=%ld\n",
		   (unsigned long)device_instance_to_external(instance),
		   (long int)nr_blocks));
    stack_returns[0] = nr_blocks;
    return 0;
  }
}

static device_instance_methods hw_disk_instance_methods[] = {
  { "max-transfer", hw_disk_max_transfer },
  { "block-size", hw_disk_block_size },
  { "#blocks", hw_disk_nr_blocks },
  { NULL, },
};

static const device_instance_callbacks hw_disk_instance_callbacks = {
  hw_disk_instance_delete,
  hw_disk_instance_read,
  hw_disk_instance_write,
  hw_disk_instance_seek,
  hw_disk_instance_methods,
};

static device_instance *
hw_disk_create_instance(device *me,
			const char *path,
			const char *args)
{
  device_instance *instance;
  hw_disk_device *disk = device_data(me);
  hw_disk_instance *data = ZALLOC(hw_disk_instance);
  data->disk = disk;
  data->pos = 0;
  instance = device_create_instance_from(me, NULL,
					 data,
					 path, args,
					 &hw_disk_instance_callbacks);
  DITRACE(disk, ("create - path=%s(%s) instance=%ld\n",
		 path, args,
		 (unsigned long)device_instance_to_external(instance)));
  return pk_disklabel_create_instance(instance, args);
}

static device_callbacks const hw_disk_callbacks = {
  { hw_disk_init_address, NULL },
  { NULL, }, /* address */
  { hw_disk_io_read_buffer,
      hw_disk_io_write_buffer, },
  { NULL, }, /* DMA */
  { NULL, }, /* interrupt */
  { NULL, }, /* unit */
  hw_disk_create_instance,
  hw_disk_ioctl,
};


static void *
hw_disk_create(const char *name,
	       const device_unit *unit_address,
	       const char *args)
{
  /* create the descriptor */
  hw_disk_device *hw_disk = ZALLOC(hw_disk_device);
  return hw_disk;
}


const device_descriptor hw_disk_device_descriptor[] = {
  { "disk", hw_disk_create, &hw_disk_callbacks },
  { "cdrom", hw_disk_create, &hw_disk_callbacks },
  { "floppy", hw_disk_create, &hw_disk_callbacks },
  { NULL },
};

#endif /* _HW_DISK_C_ */