+extern int serial_setstopbits (struct serial *scb, int num);
+
+/* Asynchronous serial interface: */
+
+/* Can the serial device support asynchronous mode? */
+
+extern int serial_can_async_p (struct serial *scb);
+
+/* Has the serial device been put in asynchronous mode? */
+
+extern int serial_is_async_p (struct serial *scb);
+
+/* For ASYNC enabled devices, register a callback and enable
+ asynchronous mode. To disable asynchronous mode, register a NULL
+ callback. */
+
+typedef void (serial_event_ftype) (struct serial *scb, void *context);
+extern void serial_async (struct serial *scb, serial_event_ftype *handler, void *context);
+
+/* Provide direct access to the underlying FD (if any) used to
+ implement the serial device. This interface is clearly
+ deprecated. Will call internal_error() if the operation isn't
+ applicable to the current serial device. */
+
+extern int deprecated_serial_fd (struct serial *scb);
+
+/* Trace/debug mechanism.
+
+ serial_debug() enables/disables internal debugging.
+ serial_debug_p() indicates the current debug state. */
+
+extern void serial_debug (struct serial *scb, int debug_p);
+
+extern int serial_debug_p (struct serial *scb);
+
+
+/* Details of an instance of a serial object */
+
+struct serial
+ {
+ int fd; /* File descriptor */
+ /* File descriptor for a separate error stream that should be
+ immediately forwarded to gdb_stderr. This may be -1.
+ If != -1, this descriptor should be non-blocking or
+ ops->avail should be non-NULL. */
+ int error_fd;
+ struct serial_ops *ops; /* Function vector */
+ void *state; /* Local context info for open FD */
+ serial_ttystate ttystate; /* Not used (yet) */
+ int bufcnt; /* Amount of data remaining in receive
+ buffer. -ve for sticky errors. */
+ unsigned char *bufp; /* Current byte */
+ unsigned char buf[BUFSIZ]; /* Da buffer itself */
+ int current_timeout; /* (ser-unix.c termio{,s} only), last
+ value of VTIME */
+ int timeout_remaining; /* (ser-unix.c termio{,s} only), we
+ still need to wait for this many
+ more seconds. */
+ char *name; /* The name of the device or host */
+ struct serial *next; /* Pointer to the next `struct serial *' */
+ int refcnt; /* Number of pointers to this block */
+ int debug_p; /* Trace this serial devices operation. */
+ int async_state; /* Async internal state. */
+ void *async_context; /* Async event thread's context */
+ serial_event_ftype *async_handler;/* Async event handler */
+ };
+
+struct serial_ops
+ {
+ char *name;
+ struct serial_ops *next;
+ int (*open) (struct serial *, const char *name);
+ void (*close) (struct serial *);
+ int (*readchar) (struct serial *, int timeout);
+ int (*write) (struct serial *, const char *str, int len);
+ /* Discard pending output */
+ int (*flush_output) (struct serial *);
+ /* Discard pending input */
+ int (*flush_input) (struct serial *);
+ int (*send_break) (struct serial *);
+ void (*go_raw) (struct serial *);
+ serial_ttystate (*get_tty_state) (struct serial *);
+ int (*set_tty_state) (struct serial *, serial_ttystate);
+ void (*print_tty_state) (struct serial *, serial_ttystate,
+ struct ui_file *);
+ int (*noflush_set_tty_state) (struct serial *, serial_ttystate,
+ serial_ttystate);
+ int (*setbaudrate) (struct serial *, int rate);
+ int (*setstopbits) (struct serial *, int num);
+ /* Wait for output to drain */
+ int (*drain_output) (struct serial *);
+ /* Change the serial device into/out of asynchronous mode, call
+ the specified function when ever there is something
+ interesting. */
+ void (*async) (struct serial *scb, int async_p);
+ /* Perform a low-level read operation, reading (at most) COUNT
+ bytes into SCB->BUF. Return zero at end of file. */
+ int (*read_prim)(struct serial *scb, size_t count);
+ /* Perform a low-level write operation, writing (at most) COUNT
+ bytes from BUF. */
+ int (*write_prim)(struct serial *scb, const void *buf, size_t count);
+ /* Return that number of bytes that can be read from FD
+ without blocking. Return value of -1 means that the
+ the read will not block even if less that requested bytes
+ are available. */
+ int (*avail)(struct serial *scb, int fd);
+
+#ifdef USE_WIN32API
+ /* Return a handle to wait on, indicating available data from SCB
+ when signaled, in *READ. Return a handle indicating errors
+ in *EXCEPT. */
+ void (*wait_handle) (struct serial *scb, HANDLE *read, HANDLE *except);
+ void (*done_wait_handle) (struct serial *scb);
+#endif /* USE_WIN32API */
+ };