static int xd_ioctl (struct inode *inode,struct file *file,unsigned int cmd,unsigned long arg);
static int xd_readwrite (u_char operation,XD_INFO *disk,char *buffer,u_int block,u_int count);
static void xd_recalibrate (u_char drive);
static int xd_ioctl (struct inode *inode,struct file *file,unsigned int cmd,unsigned long arg);
static int xd_readwrite (u_char operation,XD_INFO *disk,char *buffer,u_int block,u_int count);
static void xd_recalibrate (u_char drive);