* Makefile.in (SFILES OBS): Add serial.[co] & ser-hardwire.[co].

These implement a new serial line interface for talking to remote
	targets.
	* configure.in:  Link ser-hardwire.c to ser-unix.c for all hosts,
	EXCEPT go32, which gets ser-go32.c.
	* remote.c:  Use new serial interface.  More remote-xxx's to be
	converted later.
	* ser-bsd.c, ser-termios.c:  Removed.
	* serial.c:  New.  Implements common operations for all serial
	types.
	* ser-unix.c:  New.  Unix specific serial operations for various
	flavors of Unix (Posix, SysV, BSD).
	* serial.h:  Generic serial interface defs.
	* config/i386/go32.mh, config/i386/i386bsd.h,
	config/m68k/apollo68b.mh, config/sparc/sun4os4.mh:  Remove
	ser-bsd.o from XDEPFILES.  All the magic is now handled in
	configure.in.

gdb/serial.c

@@ -0,0 +1,181 @@
+/* Generic serial interface routines
+   Copyright 1992, 1993 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "defs.h"
+#include "serial.h"
+
+/* Open up a device or a network socket, depending upon the syntax of NAME. */
+
+static struct serial_ops *serial_ops_list = NULL;
+
+static struct serial_ops *
+serial_interface_lookup (name)
+     char *name;
+{
+  struct serial_ops *ops;
+
+  for (ops = serial_ops_list; ops; ops = ops->next)
+    if (strcmp (name, ops->name) == 0)
+      return ops;
+
+  return NULL;
+}
+
+void
+serial_add_interface(optable)
+     struct serial_ops *optable;
+{
+  optable->next = serial_ops_list;
+  serial_ops_list = optable;
+}
+
+serial_t
+serial_open(name)
+     const char *name;
+{
+  serial_t scb;
+  struct serial_ops *ops;
+
+  ops = serial_interface_lookup ("hardwire");
+
+  if (!ops)
+    return NULL;
+
+  scb = (serial_t)xmalloc (sizeof (struct _serial_t));
+
+  scb->ops = ops;
+
+  scb->bufcnt = 0;
+  scb->bufp = scb->buf;
+
+  if (SERIAL_OPEN (scb, name))
+    {
+      free (scb);
+      return NULL;
+    }
+
+  return scb;
+}
+
+#if 0
+/* Connect the user directly to the remote system.  This command acts just like
+   the 'cu' or 'tip' command.  Use <CR>~. or <CR>~^D to break out.  */
+
+static void
+cleanup_tty(ttystate)
+     struct ttystate ttystate;
+{
+  printf("\r\n[Exiting connect mode]\r\n");
+  serial_restore(0, &ttystate);
+}
+
+static void
+connect_command (args, fromtty)
+     char	*args;
+     int	fromtty;
+{
+  fd_set readfds;
+  int numfds;
+  int c;
+  char cur_esc = 0;
+  static struct ttystate ttystate;
+
+  dont_repeat();
+
+  if (desc < 0)
+    error("target not open.");
+  
+  if (args)
+    fprintf("This command takes no args.  They have been ignored.\n");
+	
+  printf("[Entering connect mode.  Use ~. or ~^D to escape]\n");
+
+  serial_raw(0, &ttystate);
+
+  make_cleanup(cleanup_tty, &ttystate);
+
+  FD_ZERO(&readfds);
+
+  while (1)
+    {
+      do
+	{
+	  FD_SET(0, &readfds);
+	  FD_SET(desc, &readfds);
+	  numfds = select(sizeof(readfds)*8, &readfds, 0, 0, 0);
+	}
+      while (numfds == 0);
+
+      if (numfds < 0)
+	perror_with_name("select");
+
+      if (FD_ISSET(0, &readfds))
+	{			/* tty input, send to stdebug */
+	  char cx;
+
+	  c = serial_readchar(-1);
+	  if (c < 0)
+	    perror_with_name("connect");
+
+	  cx = c;
+	  serial_write(&cx, 1);
+	  switch (cur_esc)
+	    {
+	    case 0:
+	      if (c == '\r')
+		cur_esc = c;
+	      break;
+	    case '\r':
+	      if (c == '~')
+		cur_esc = c;
+	      else
+		cur_esc = 0;
+	      break;
+	    case '~':
+	      if (c == '.' || c == '\004')
+		return;
+	      else
+		cur_esc = 0;
+	    }
+	}
+
+      if (FD_ISSET(desc, &readfds))
+	{
+	  while (1)
+	    {
+	      c = serial_readchar(-1);
+	      if (c < 0)
+		break;
+	      putchar(c);
+	    }
+	  fflush(stdout);
+	}
+    }
+}
+#endif
+
+#if 0
+void
+_initialize_serial ()
+{
+  add_com ("connect", class_obscure, connect_command,
+	   "Connect the terminal directly up to the command monitor.\n\
+Use <CR>~. or <CR>~^D to break out.");
+}
+#endif