Thu Jun 4 08:25:38 1998 Michael Snyder <msnyder@cleaver.cygnus.com>

        * remote.c (remote_compare_command): New function, new command.
        Compare object file binary image with corresponding memory on
        remote target.  Report differences.

2 files changed, 4388 insertions, 1 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index bc922ef..01e2496 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+Thu Jun  4 08:25:38 1998  Michael Snyder  <msnyder@cleaver.cygnus.com>
+
+	* remote.c (remote_compare_command): New function, new command.
+	Compare object file binary image with corresponding memory on
+	remote target.  Report differences.
+
 Tue Jun  2 19:05:04 1998  Mark Alexander  <marka@cygnus.com>
 
 	* sparc-tdep.c (sparc_target_architecture_hook): Set target
diff --git a/gdb/remote.c b/gdb/remote.c
index 02b31cc..00f7dbc 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -725,8 +725,4173 @@ device is attached to the remote system (e.g. /dev/ttya).");
      (we'd be in an inconsistent state otherwise).  */
   if (!catch_errors (remote_start_remote, (char *)0, 
 		     "Couldn't establish connection to remote target\n", RETURN_MASK_ALL))
-    pop_target();
+    {
+      pop_target();
+      return;
+    }
+
+  if (extended_p)
+    {
+      /* tell the remote that we're using the extended protocol.  */
+      char buf[PBUFSIZ];
+      putpkt ("!");
+      getpkt (buf, 0);
+    }
+}
+
+/* This takes a program previously attached to and detaches it.  After
+   this is done, GDB can be used to debug some other program.  We
+   better not have left any breakpoints in the target program or it'll
+   die when it hits one.  */
+
+static void
+remote_detach (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  char buf[PBUFSIZ];
+
+  if (args)
+    error ("Argument given to \"detach\" when remotely debugging.");
+
+  /* Tell the remote target to detach.  */
+  strcpy (buf, "D");
+  remote_send (buf);
+
+  pop_target ();
+  if (from_tty)
+    puts_filtered ("Ending remote debugging.\n");
+}
+
+/* Convert hex digit A to a number.  */
+
+int
+fromhex (a)
+     int a;
+{
+  if (a >= '0' && a <= '9')
+    return a - '0';
+  else if (a >= 'a' && a <= 'f')
+    return a - 'a' + 10;
+  else if (a >= 'A' && a <= 'F')
+    return a - 'A' + 10;
+  else 
+    error ("Reply contains invalid hex digit %d", a);
+}
+
+/* Convert number NIB to a hex digit.  */
+
+static int
+tohex (nib)
+     int nib;
+{
+  if (nib < 10)
+    return '0'+nib;
+  else
+    return 'a'+nib-10;
+}
+
+/* Tell the remote machine to resume.  */
+
+static enum target_signal last_sent_signal = TARGET_SIGNAL_0;
+int last_sent_step;
+
+static void
+remote_resume (pid, step, siggnal)
+     int pid, step;
+     enum target_signal siggnal;
+{
+  char buf[PBUFSIZ];
+
+  if (pid == -1)
+    set_thread (inferior_pid, 0);
+  else
+    set_thread (pid, 0);
+
+  dcache_flush (remote_dcache);
+
+  last_sent_signal = siggnal;
+  last_sent_step = step;
+
+  /* A hook for when we need to do something at the last moment before
+     resumption.  */
+  if (target_resume_hook)
+    (*target_resume_hook) ();
+
+  if (siggnal != TARGET_SIGNAL_0)
+    {
+      buf[0] = step ? 'S' : 'C';
+      buf[1] = tohex (((int)siggnal >> 4) & 0xf);
+      buf[2] = tohex ((int)siggnal & 0xf);
+      buf[3] = '\0';
+    }
+  else
+    strcpy (buf, step ? "s": "c");
+
+  putpkt (buf);
+}
+
+/* Send ^C to target to halt it.  Target will respond, and send us a
+   packet.  */
+
+static void
+remote_interrupt (signo)
+     int signo;
+{
+  /* If this doesn't work, try more severe steps.  */
+  signal (signo, remote_interrupt_twice);
+  
+  if (remote_debug)
+    printf_unfiltered ("remote_interrupt called\n");
+
+  /* Send a break or a ^C, depending on user preference.  */
+  if (remote_break)
+    SERIAL_SEND_BREAK (remote_desc);
+  else
+    SERIAL_WRITE (remote_desc, "\003", 1);
+}
+
+static void (*ofunc)();
+
+/* The user typed ^C twice.  */
+static void
+remote_interrupt_twice (signo)
+     int signo;
+{
+  signal (signo, ofunc);
+  
+  interrupt_query ();
+
+  signal (signo, remote_interrupt);
+}
+
+/* Ask the user what to do when an interrupt is received.  */
+
+static void
+interrupt_query ()
+{
+  target_terminal_ours ();
+
+  if (query ("Interrupted while waiting for the program.\n\
+Give up (and stop debugging it)? "))
+    {
+      target_mourn_inferior ();
+      return_to_top_level (RETURN_QUIT);
+    }
+
+  target_terminal_inferior ();
+}
+
+/* If nonzero, ignore the next kill.  */
+int kill_kludge;
+
+void
+remote_console_output (msg)
+     char *msg;
+{
+  char *p;
+
+  for (p = msg; *p; p +=2) 
+    {
+      char tb[2];
+      char c = fromhex (p[0]) * 16 + fromhex (p[1]);
+      tb[0] = c;
+      tb[1] = 0;
+      if (target_output_hook)
+	target_output_hook (tb);
+      else 
+	fputs_filtered (tb, gdb_stdout);
+    }
+}
+
+/* Wait until the remote machine stops, then return,
+   storing status in STATUS just as `wait' would.
+   Returns "pid" (though it's not clear what, if anything, that
+   means in the case of this target).  */
+
+static int
+remote_wait (pid, status)
+     int pid;
+     struct target_waitstatus *status;
+{
+  unsigned char buf[PBUFSIZ];
+  int thread_num = -1;
+
+  status->kind = TARGET_WAITKIND_EXITED;
+  status->value.integer = 0;
+
+  while (1)
+    {
+      unsigned char *p;
+
+      ofunc = (void (*)()) signal (SIGINT, remote_interrupt);
+      getpkt ((char *) buf, 1);
+      signal (SIGINT, ofunc);
+
+      /* This is a hook for when we need to do something (perhaps the
+	 collection of trace data) every time the target stops.  */
+      if (target_wait_loop_hook)
+	(*target_wait_loop_hook) ();
+
+      switch (buf[0])
+	{
+	case 'E':		/* Error of some sort */
+	  warning ("Remote failure reply: %s", buf);
+	  continue;
+	case 'T':		/* Status with PC, SP, FP, ... */
+	  {
+	    int i;
+	    long regno;
+	    char regs[MAX_REGISTER_RAW_SIZE];
+
+	    /* Expedited reply, containing Signal, {regno, reg} repeat */
+	    /*  format is:  'Tssn...:r...;n...:r...;n...:r...;#cc', where
+		ss = signal number
+		n... = register number
+		r... = register contents
+		*/
+	    p = &buf[3];	/* after Txx */
+
+	    while (*p)
+	      {
+		unsigned char *p1;
+		char *p_temp;
+
+		regno = strtol ((const char *) p, &p_temp, 16); /* Read the register number */
+		p1 = (unsigned char *)p_temp;
+
+		if (p1 == p)
+		  {
+		    p1 = (unsigned char *) strchr ((const char *) p, ':');
+		    if (p1 == NULL)
+		      warning ("Malformed packet (missing colon): %s\n\
+Packet: '%s'\n",
+			       p, buf);
+		    if (strncmp ((const char *) p, "thread", p1 - p) == 0)
+		      {
+			thread_num = strtol ((const char *) ++p1, &p_temp, 16);
+			p = (unsigned char *)p_temp;
+		      }
+		  }
+		else
+		  {
+		    p = p1;
+
+		    if (*p++ != ':')
+		      warning ("Malformed packet (missing colon): %s\n\
+Packet: '%s'\n",
+			       p, buf);
+
+		    if (regno >= NUM_REGS)
+		      warning ("Remote sent bad register number %ld: %s\n\
+Packet: '%s'\n",
+			       regno, p, buf);
+
+		    for (i = 0; i < REGISTER_RAW_SIZE (regno); i++)
+		      {
+			if (p[0] == 0 || p[1] == 0)
+			  warning ("Remote reply is too short: %s", buf);
+			regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+			p += 2;
+		      }
+		    supply_register (regno, regs);
+		  }
+
+		if (*p++ != ';')
+		  warning ("Remote register badly formatted: %s", buf);
+	      }
+	  }
+	  /* fall through */
+	case 'S':		/* Old style status, just signal only */
+	  status->kind = TARGET_WAITKIND_STOPPED;
+	  status->value.sig = (enum target_signal)
+	    (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
+
+	  goto got_status;
+	case 'W':		/* Target exited */
+	  {
+	    /* The remote process exited.  */
+	    status->kind = TARGET_WAITKIND_EXITED;
+	    status->value.integer = (fromhex (buf[1]) << 4) + fromhex (buf[2]);
+	    goto got_status;
+	  }
+	case 'X':
+	  status->kind = TARGET_WAITKIND_SIGNALLED;
+	  status->value.sig = (enum target_signal)
+	    (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
+	  kill_kludge = 1;
+
+	  goto got_status;
+	case 'O':		/* Console output */
+	  remote_console_output (buf + 1);
+	  continue;
+	case '\0':
+	  if (last_sent_signal != TARGET_SIGNAL_0)
+	    {
+	      /* Zero length reply means that we tried 'S' or 'C' and
+		 the remote system doesn't support it.  */
+	      target_terminal_ours_for_output ();
+	      printf_filtered
+		("Can't send signals to this remote system.  %s not sent.\n",
+		 target_signal_to_name (last_sent_signal));
+	      last_sent_signal = TARGET_SIGNAL_0;
+	      target_terminal_inferior ();
+
+	      strcpy ((char *) buf, last_sent_step ? "s" : "c");
+	      putpkt ((char *) buf);
+	      continue;
+	    }
+	  /* else fallthrough */
+	default:
+	  warning ("Invalid remote reply: %s", buf);
+	  continue;
+	}
+    }
+ got_status:
+  if (thread_num != -1)
+    {
+      /* Initial thread value can only be acquired via wait, so deal with
+	 this marker which is used before the first thread value is
+	 acquired.  */
+      if (inferior_pid == 42000)
+	{
+	  inferior_pid = thread_num;
+	  add_thread (inferior_pid);
+	}
+      return thread_num;
+    }
+  return inferior_pid;
+}
+
+/* Number of bytes of registers this stub implements.  */
+static int register_bytes_found;
+
+/* Read the remote registers into the block REGS.  */
+/* Currently we just read all the registers, so we don't use regno.  */
+/* ARGSUSED */
+static void
+remote_fetch_registers (regno)
+     int regno;
+{
+  char buf[PBUFSIZ];
+  int i;
+  char *p;
+  char regs[REGISTER_BYTES];
+
+  set_thread (inferior_pid, 1);
+
+  sprintf (buf, "g");
+  remote_send (buf);
+
+  if (remote_register_buf_size == 0)
+    remote_register_buf_size = strlen (buf);
+
+  /* Unimplemented registers read as all bits zero.  */
+  memset (regs, 0, REGISTER_BYTES);
+
+  /* We can get out of synch in various cases.  If the first character
+     in the buffer is not a hex character, assume that has happened
+     and try to fetch another packet to read.  */
+  while ((buf[0] < '0' || buf[0] > '9')
+	 && (buf[0] < 'a' || buf[0] > 'f'))
+    {
+      if (remote_debug)
+	printf_unfiltered ("Bad register packet; fetching a new packet\n");
+      getpkt (buf, 0);
+    }
+
+  /* Reply describes registers byte by byte, each byte encoded as two
+     hex characters.  Suck them all up, then supply them to the
+     register cacheing/storage mechanism.  */
+
+  p = buf;
+  for (i = 0; i < REGISTER_BYTES; i++)
+    {
+      if (p[0] == 0)
+	break;
+      if (p[1] == 0)
+	{
+	  warning ("Remote reply is of odd length: %s", buf);
+	  /* Don't change register_bytes_found in this case, and don't
+	     print a second warning.  */
+	  goto supply_them;
+	}
+      regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+      p += 2;
+    }
+
+  if (i != register_bytes_found)
+    {
+      register_bytes_found = i;
+#ifdef REGISTER_BYTES_OK
+      if (!REGISTER_BYTES_OK (i))
+	warning ("Remote reply is too short: %s", buf);
+#endif
+    }
+
+ supply_them:
+  for (i = 0; i < NUM_REGS; i++)
+    supply_register (i, &regs[REGISTER_BYTE(i)]);
+}
+
+/* Prepare to store registers.  Since we may send them all (using a
+   'G' request), we have to read out the ones we don't want to change
+   first.  */
+
+static void 
+remote_prepare_to_store ()
+{
+  /* Make sure the entire registers array is valid.  */
+  read_register_bytes (0, (char *)NULL, REGISTER_BYTES);
+}
+
+/* Store register REGNO, or all registers if REGNO == -1, from the contents
+   of REGISTERS.  FIXME: ignores errors.  */
+
+static void
+remote_store_registers (regno)
+     int regno;
+{
+  char buf[PBUFSIZ];
+  int i;
+  char *p;
+
+  set_thread (inferior_pid, 1);
+
+  if (regno >= 0 && stub_supports_P)
+    {
+      /* Try storing a single register.  */
+      char *regp;
+
+      sprintf (buf, "P%x=", regno);
+      p = buf + strlen (buf);
+      regp = &registers[REGISTER_BYTE (regno)];
+      for (i = 0; i < REGISTER_RAW_SIZE (regno); ++i)
+	{
+	  *p++ = tohex ((regp[i] >> 4) & 0xf);
+	  *p++ = tohex (regp[i] & 0xf);
+	}
+      *p = '\0';
+      remote_send (buf);
+      if (buf[0] != '\0')
+	{
+	  /* The stub understands the 'P' request.  We are done.  */
+	  return;
+	}
+
+      /* The stub does not support the 'P' request.  Use 'G' instead,
+	 and don't try using 'P' in the future (it will just waste our
+	 time).  */
+      stub_supports_P = 0;
+    }
+
+  buf[0] = 'G';
+
+  /* Command describes registers byte by byte,
+     each byte encoded as two hex characters.  */
+
+  p = buf + 1;
+  /* remote_prepare_to_store insures that register_bytes_found gets set.  */
+  for (i = 0; i < register_bytes_found; i++)
+    {
+      *p++ = tohex ((registers[i] >> 4) & 0xf);
+      *p++ = tohex (registers[i] & 0xf);
+    }
+  *p = '\0';
+
+  remote_send (buf);
+}
+
+/* 
+   Use of the data cache *used* to be disabled because it loses for looking at
+   and changing hardware I/O ports and the like.  Accepting `volatile'
+   would perhaps be one way to fix it.  Another idea would be to use the
+   executable file for the text segment (for all SEC_CODE sections?
+   For all SEC_READONLY sections?).  This has problems if you want to
+   actually see what the memory contains (e.g. self-modifying code,
+   clobbered memory, user downloaded the wrong thing).  
+
+   Because it speeds so much up, it's now enabled, if you're playing
+   with registers you turn it of (set remotecache 0)
+*/
+
+/* Read a word from remote address ADDR and return it.
+   This goes through the data cache.  */
+
+#if 0	/* unused? */
+static int
+remote_fetch_word (addr)
+     CORE_ADDR addr;
+{
+  return dcache_fetch (remote_dcache, addr);
+}
+
+/* Write a word WORD into remote address ADDR.
+   This goes through the data cache.  */
+
+static void
+remote_store_word (addr, word)
+     CORE_ADDR addr;
+     int word;
+{
+  dcache_poke (remote_dcache, addr, word);
+}
+#endif	/* 0 (unused?) */
+
+
+
+/* Return the number of hex digits in num.  */
+
+static int
+hexnumlen (num)
+     ULONGEST num;
+{
+  int i;
+
+  for (i = 0; num != 0; i++)
+    num >>= 4;
+
+  return max (i, 1);
+}
+
+/* Write memory data directly to the remote machine.
+   This does not inform the data cache; the data cache uses this.
+   MEMADDR is the address in the remote memory space.
+   MYADDR is the address of the buffer in our space.
+   LEN is the number of bytes.
+
+   Returns number of bytes transferred, or 0 for error.  */
+
+static int
+remote_write_bytes (memaddr, myaddr, len)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+{
+  int max_buf_size;		/* Max size of packet output buffer */
+  int origlen;
+
+  /* Chop the transfer down if necessary */
+
+  max_buf_size = min (remote_write_size, PBUFSIZ);
+  if (remote_register_buf_size != 0)
+    max_buf_size = min (max_buf_size, remote_register_buf_size);
+
+  /* Subtract header overhead from max payload size -  $M<memaddr>,<len>:#nn */
+  max_buf_size -= 2 + hexnumlen (memaddr + len - 1) + 1 + hexnumlen (len) + 4;
+
+  origlen = len;
+  while (len > 0)
+    {
+      char buf[PBUFSIZ];
+      char *p;
+      int todo;
+      int i;
+
+      todo = min (len, max_buf_size / 2); /* num bytes that will fit */
+
+      /* FIXME-32x64: Need a version of print_address_numeric which puts the
+	 result in a buffer like sprintf.  */
+      sprintf (buf, "M%lx,%x:", (unsigned long) memaddr, todo);
+
+      /* We send target system values byte by byte, in increasing byte addresses,
+	 each byte encoded as two hex characters.  */
+
+      p = buf + strlen (buf);
+      for (i = 0; i < todo; i++)
+	{
+	  *p++ = tohex ((myaddr[i] >> 4) & 0xf);
+	  *p++ = tohex (myaddr[i] & 0xf);
+	}
+      *p = '\0';
+
+      putpkt (buf);
+      getpkt (buf, 0);
+
+      if (buf[0] == 'E')
+	{
+	  /* There is no correspondance between what the remote protocol uses
+	     for errors and errno codes.  We would like a cleaner way of
+	     representing errors (big enough to include errno codes, bfd_error
+	     codes, and others).  But for now just return EIO.  */
+	  errno = EIO;
+	  return 0;
+	}
+      myaddr += todo;
+      memaddr += todo;
+      len -= todo;
+    }
+  return origlen;
+}
+
+/* Read memory data directly from the remote machine.
+   This does not use the data cache; the data cache uses this.
+   MEMADDR is the address in the remote memory space.
+   MYADDR is the address of the buffer in our space.
+   LEN is the number of bytes.
+
+   Returns number of bytes transferred, or 0 for error.  */
+
+static int
+remote_read_bytes (memaddr, myaddr, len)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+{
+  int max_buf_size;		/* Max size of packet output buffer */
+  int origlen;
+
+  /* Chop the transfer down if necessary */
+
+  max_buf_size = min (remote_write_size, PBUFSIZ);
+  if (remote_register_buf_size != 0)
+    max_buf_size = min (max_buf_size, remote_register_buf_size);
+
+  origlen = len;
+  while (len > 0)
+    {
+      char buf[PBUFSIZ];
+      char *p;
+      int todo;
+      int i;
+
+      todo = min (len, max_buf_size / 2); /* num bytes that will fit */
+
+      /* FIXME-32x64: Need a version of print_address_numeric which puts the
+	 result in a buffer like sprintf.  */
+      sprintf (buf, "m%lx,%x", (unsigned long) memaddr, todo);
+      putpkt (buf);
+      getpkt (buf, 0);
+
+      if (buf[0] == 'E')
+	{
+	  /* There is no correspondance between what the remote protocol uses
+	     for errors and errno codes.  We would like a cleaner way of
+	     representing errors (big enough to include errno codes, bfd_error
+	     codes, and others).  But for now just return EIO.  */
+	  errno = EIO;
+	  return 0;
+	}
+
+  /* Reply describes memory byte by byte,
+     each byte encoded as two hex characters.  */
+
+      p = buf;
+      for (i = 0; i < todo; i++)
+	{
+	  if (p[0] == 0 || p[1] == 0)
+	    /* Reply is short.  This means that we were able to read only part
+	       of what we wanted to.  */
+	    return i + (origlen - len);
+	  myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+	  p += 2;
+	}
+      myaddr += todo;
+      memaddr += todo;
+      len -= todo;
+    }
+  return origlen;
+}
+
+/* Read or write LEN bytes from inferior memory at MEMADDR, transferring
+   to or from debugger address MYADDR.  Write to inferior if SHOULD_WRITE is
+   nonzero.  Returns length of data written or read; 0 for error.  */
+
+/* ARGSUSED */
+static int
+remote_xfer_memory(memaddr, myaddr, len, should_write, target)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+     int should_write;
+     struct target_ops *target;			/* ignored */
+{
+#ifdef REMOTE_TRANSLATE_XFER_ADDRESS
+  CORE_ADDR targaddr;
+  int targlen;
+  REMOTE_TRANSLATE_XFER_ADDRESS (memaddr, len, targaddr, targlen);
+  if (targlen == 0)
+    return 0;
+  memaddr = targaddr;
+  len = targlen;
+#endif
+
+  return dcache_xfer_memory (remote_dcache, memaddr, myaddr, len, should_write);
+}
+
+   
+#if 0
+/* Enable after 4.12.  */
+
+void
+remote_search (len, data, mask, startaddr, increment, lorange, hirange
+	       addr_found, data_found)
+     int len;
+     char *data;
+     char *mask;
+     CORE_ADDR startaddr;
+     int increment;
+     CORE_ADDR lorange;
+     CORE_ADDR hirange;
+     CORE_ADDR *addr_found;
+     char *data_found;
+{
+  if (increment == -4 && len == 4)
+    {
+      long mask_long, data_long;
+      long data_found_long;
+      CORE_ADDR addr_we_found;
+      char buf[PBUFSIZ];
+      long returned_long[2];
+      char *p;
+
+      mask_long = extract_unsigned_integer (mask, len);
+      data_long = extract_unsigned_integer (data, len);
+      sprintf (buf, "t%x:%x,%x", startaddr, data_long, mask_long);
+      putpkt (buf);
+      getpkt (buf, 0);
+      if (buf[0] == '\0')
+	{
+	  /* The stub doesn't support the 't' request.  We might want to
+	     remember this fact, but on the other hand the stub could be
+	     switched on us.  Maybe we should remember it only until
+	     the next "target remote".  */
+	  generic_search (len, data, mask, startaddr, increment, lorange,
+			  hirange, addr_found, data_found);
+	  return;
+	}
+
+      if (buf[0] == 'E')
+	/* There is no correspondance between what the remote protocol uses
+	   for errors and errno codes.  We would like a cleaner way of
+	   representing errors (big enough to include errno codes, bfd_error
+	   codes, and others).  But for now just use EIO.  */
+	memory_error (EIO, startaddr);
+      p = buf;
+      addr_we_found = 0;
+      while (*p != '\0' && *p != ',')
+	addr_we_found = (addr_we_found << 4) + fromhex (*p++);
+      if (*p == '\0')
+	error ("Protocol error: short return for search");
+
+      data_found_long = 0;
+      while (*p != '\0' && *p != ',')
+	data_found_long = (data_found_long << 4) + fromhex (*p++);
+      /* Ignore anything after this comma, for future extensions.  */
+
+      if (addr_we_found < lorange || addr_we_found >= hirange)
+	{
+	  *addr_found = 0;
+	  return;
+	}
+
+      *addr_found = addr_we_found;
+      *data_found = store_unsigned_integer (data_we_found, len);
+      return;
+    }
+  generic_search (len, data, mask, startaddr, increment, lorange,
+		  hirange, addr_found, data_found);
+}
+#endif /* 0 */
+
+static void
+remote_files_info (ignore)
+     struct target_ops *ignore;
+{
+  puts_filtered ("Debugging a target over a serial line.\n");
+}
+
+/* Stuff for dealing with the packets which are part of this protocol.
+   See comment at top of file for details.  */
+
+/* Read a single character from the remote end, masking it down to 7 bits. */
+
+static int
+readchar (timeout)
+     int timeout;
+{
+  int ch;
+
+  ch = SERIAL_READCHAR (remote_desc, timeout);
+
+  switch (ch)
+    {
+    case SERIAL_EOF:
+      error ("Remote connection closed");
+    case SERIAL_ERROR:
+      perror_with_name ("Remote communication error");
+    case SERIAL_TIMEOUT:
+      return ch;
+    default:
+      return ch & 0x7f;
+    }
+}
+
+/* Send the command in BUF to the remote machine,
+   and read the reply into BUF.
+   Report an error if we get an error reply.  */
+
+static void
+remote_send (buf)
+     char *buf;
+{
+  putpkt (buf);
+  getpkt (buf, 0);
+
+  if (buf[0] == 'E')
+    error ("Remote failure reply: %s", buf);
+}
+
+/* Send a packet to the remote machine, with error checking.
+   The data of the packet is in BUF.  */
+
+int
+putpkt (buf)
+     char *buf;
+{
+  int i;
+  unsigned char csum = 0;
+  char buf2[PBUFSIZ];
+  int cnt = strlen (buf);
+  int ch;
+  int tcount = 0;
+  char *p;
+
+  /* Copy the packet into buffer BUF2, encapsulating it
+     and giving it a checksum.  */
+
+  if (cnt > (int) sizeof (buf2) - 5)		/* Prosanity check */
+    abort();
+
+  p = buf2;
+  *p++ = '$';
+
+  for (i = 0; i < cnt; i++)
+    {
+      csum += buf[i];
+      *p++ = buf[i];
+    }
+  *p++ = '#';
+  *p++ = tohex ((csum >> 4) & 0xf);
+  *p++ = tohex (csum & 0xf);
+
+  /* Send it over and over until we get a positive ack.  */
+
+  while (1)
+    {
+      int started_error_output = 0;
+
+      if (remote_debug)
+	{
+	  *p = '\0';
+	  printf_unfiltered ("Sending packet: %s...", buf2);
+	  gdb_flush(gdb_stdout);
+	}
+      if (SERIAL_WRITE (remote_desc, buf2, p - buf2))
+	perror_with_name ("putpkt: write failed");
+
+      /* read until either a timeout occurs (-2) or '+' is read */
+      while (1)
+	{
+	  ch = readchar (remote_timeout);
+
+ 	  if (remote_debug)
+	    {
+	      switch (ch)
+		{
+		case '+':
+		case SERIAL_TIMEOUT:
+		case '$':
+		  if (started_error_output)
+		    {
+		      putchar_unfiltered ('\n');
+		      started_error_output = 0;
+		    }
+		}
+	    }
+
+	  switch (ch)
+	    {
+	    case '+':
+	      if (remote_debug)
+		printf_unfiltered("Ack\n");
+	      return 1;
+	    case SERIAL_TIMEOUT:
+	      tcount ++;
+	      if (tcount > 3)
+		return 0;
+	      break;		/* Retransmit buffer */
+	    case '$':
+	      {
+		char junkbuf[PBUFSIZ];
+
+	      /* It's probably an old response, and we're out of sync.  Just
+		 gobble up the packet and ignore it.  */
+		getpkt (junkbuf, 0);
+		continue;		/* Now, go look for + */
+	      }
+	    default:
+	      if (remote_debug)
+		{
+		  if (!started_error_output)
+		    {
+		      started_error_output = 1;
+		      printf_unfiltered ("putpkt: Junk: ");
+		    }
+		  putchar_unfiltered (ch & 0177);
+		}
+	      continue;
+	    }
+	  break;		/* Here to retransmit */
+	}
+
+#if 0
+      /* This is wrong.  If doing a long backtrace, the user should be
+	 able to get out next time we call QUIT, without anything as violent
+	 as interrupt_query.  If we want to provide a way out of here
+	 without getting to the next QUIT, it should be based on hitting
+	 ^C twice as in remote_wait.  */
+      if (quit_flag)
+	{
+	  quit_flag = 0;
+	  interrupt_query ();
+	}
+#endif
+    }
+}
+
+/* Come here after finding the start of the frame.  Collect the rest into BUF,
+   verifying the checksum, length, and handling run-length compression.
+   Returns 0 on any error, 1 on success.  */
+
+static int
+read_frame (buf)
+     char *buf;
+{
+  unsigned char csum;
+  char *bp;
+  int c;
+
+  csum = 0;
+  bp = buf;
+
+  while (1)
+    {
+      c = readchar (remote_timeout);
+
+      switch (c)
+	{
+	case SERIAL_TIMEOUT:
+	  if (remote_debug)
+	    puts_filtered ("Timeout in mid-packet, retrying\n");
+	  return 0;
+	case '$':
+	  if (remote_debug)
+	    puts_filtered ("Saw new packet start in middle of old one\n");
+	  return 0;		/* Start a new packet, count retries */
+	case '#':
+	  {
+	    unsigned char pktcsum;
+
+	    *bp = '\000';
+
+	    pktcsum = fromhex (readchar (remote_timeout)) << 4;
+	    pktcsum |= fromhex (readchar (remote_timeout));
+
+	    if (csum == pktcsum)
+	      return 1;
+
+	    if (remote_debug) 
+	      {
+		printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=",
+				 pktcsum, csum);
+		puts_filtered (buf);
+		puts_filtered ("\n");
+	      }
+	    return 0;
+	  }
+	case '*':		/* Run length encoding */
+	  csum += c;
+	  c = readchar (remote_timeout);
+	  csum += c;
+	  c = c - ' ' + 3;	/* Compute repeat count */
+
+
+	  if (c > 0 && c < 255 && bp + c - 1 < buf + PBUFSIZ - 1)
+	    {
+	      memset (bp, *(bp - 1), c);
+	      bp += c;
+	      continue;
+	    }
+
+	  *bp = '\0';
+	  printf_filtered ("Repeat count %d too large for buffer: ", c);
+	  puts_filtered (buf);
+	  puts_filtered ("\n");
+	  return 0;
+
+	default:
+	  if (bp < buf + PBUFSIZ - 1)
+	    {
+	      *bp++ = c;
+	      csum += c;
+	      continue;
+	    }
+
+	  *bp = '\0';
+	  puts_filtered ("Remote packet too long: ");
+	  puts_filtered (buf);
+	  puts_filtered ("\n");
+
+	  return 0;
+	}
+    }
+}
+
+/* Read a packet from the remote machine, with error checking,
+   and store it in BUF.  BUF is expected to be of size PBUFSIZ.
+   If FOREVER, wait forever rather than timing out; this is used
+   while the target is executing user code.  */
+
+void
+getpkt (buf, forever)
+     char *buf;
+     int forever;
+{
+  int c;
+  int tries;
+  int timeout;
+  int val;
+
+  strcpy (buf,"timeout");
+
+  if (forever)
+    {
+#ifdef MAINTENANCE_CMDS
+      timeout = watchdog > 0 ? watchdog : -1;
+#else
+      timeout = -1;
+#endif
+    }
+
+  else
+    timeout = remote_timeout;
+
+#define MAX_TRIES 3
+
+  for (tries = 1; tries <= MAX_TRIES; tries++)
+    {
+      /* This can loop forever if the remote side sends us characters
+	 continuously, but if it pauses, we'll get a zero from readchar
+	 because of timeout.  Then we'll count that as a retry.  */
+
+      /* Note that we will only wait forever prior to the start of a packet.
+	 After that, we expect characters to arrive at a brisk pace.  They
+	 should show up within remote_timeout intervals.  */
+
+      do
+	{
+	  c = readchar (timeout);
+
+	  if (c == SERIAL_TIMEOUT)
+	    {
+#ifdef MAINTENANCE_CMDS
+	      if (forever)	/* Watchdog went off.  Kill the target. */
+		{
+		  target_mourn_inferior ();
+		  error ("Watchdog has expired.  Target detached.\n");
+		}
+#endif
+	      if (remote_debug)
+		puts_filtered ("Timed out.\n");
+	      goto retry;
+	    }
+	}
+      while (c != '$');
+
+      /* We've found the start of a packet, now collect the data.  */
+
+      val = read_frame (buf);
+
+      if (val == 1)
+	{
+	  if (remote_debug)
+	    fprintf_unfiltered (gdb_stdout, "Packet received: %s\n", buf);
+	  SERIAL_WRITE (remote_desc, "+", 1);
+	  return;
+	}
+
+      /* Try the whole thing again.  */
+    retry:
+      SERIAL_WRITE (remote_desc, "-", 1);
+    }
+
+  /* We have tried hard enough, and just can't receive the packet.  Give up. */
+
+  printf_unfiltered ("Ignoring packet error, continuing...\n");
+  SERIAL_WRITE (remote_desc, "+", 1);
+}
+
+static void
+remote_kill ()
+{
+  /* For some mysterious reason, wait_for_inferior calls kill instead of
+     mourn after it gets TARGET_WAITKIND_SIGNALLED.  Work around it.  */
+  if (kill_kludge)
+    {
+      kill_kludge = 0;
+      target_mourn_inferior ();
+      return;
+    }
+
+  /* Use catch_errors so the user can quit from gdb even when we aren't on
+     speaking terms with the remote system.  */
+  catch_errors (putpkt, "k", "", RETURN_MASK_ERROR);
+
+  /* Don't wait for it to die.  I'm not really sure it matters whether
+     we do or not.  For the existing stubs, kill is a noop.  */
+  target_mourn_inferior ();
+}
+
+static void
+remote_mourn ()
+{
+  remote_mourn_1 (&remote_ops);
+}
+
+static void
+extended_remote_mourn ()
+{
+  /* We do _not_ want to mourn the target like this; this will
+     remove the extended remote target  from the target stack,
+     and the next time the user says "run" it'll fail. 
+
+     FIXME: What is the right thing to do here?  */
+#if 0
+  remote_mourn_1 (&extended_remote_ops);
+#endif
+}
+
+/* Worker function for remote_mourn.  */
+static void
+remote_mourn_1 (target)
+     struct target_ops *target;
+{
+  unpush_target (target);
+  generic_mourn_inferior ();
+}
+
+/* In the extended protocol we want to be able to do things like
+   "run" and have them basically work as expected.  So we need
+   a special create_inferior function. 
+
+   FIXME: One day add support for changing the exec file
+   we're debugging, arguments and an environment.  */
+
+static void
+extended_remote_create_inferior (exec_file, args, env)
+     char *exec_file;
+     char *args;
+     char **env;
+{
+  /* Rip out the breakpoints; we'll reinsert them after restarting
+     the remote server.  */
+  remove_breakpoints ();
+
+  /* Now restart the remote server.  */
+  extended_remote_restart ();
+
+  /* Now put the breakpoints back in.  This way we're safe if the
+     restart function works via a unix fork on the remote side.  */
+  insert_breakpoints ();
+
+  /* Clean up from the last time we were running.  */
+  clear_proceed_status ();
+
+  /* Let the remote process run.  */
+  proceed (-1, TARGET_SIGNAL_0, 0);
+}
+
+
+/* On some machines, e.g. 68k, we may use a different breakpoint instruction
+   than other targets; in those use REMOTE_BREAKPOINT instead of just
+   BREAKPOINT.  Also, bi-endian targets may define LITTLE_REMOTE_BREAKPOINT
+   and BIG_REMOTE_BREAKPOINT.  If none of these are defined, we just call
+   the standard routines that are in mem-break.c.  */
+
+/* FIXME, these ought to be done in a more dynamic fashion.  For instance,
+   the choice of breakpoint instruction affects target program design and
+   vice versa, and by making it user-tweakable, the special code here
+   goes away and we need fewer special GDB configurations.  */
+
+#if defined (LITTLE_REMOTE_BREAKPOINT) && defined (BIG_REMOTE_BREAKPOINT) && !defined(REMOTE_BREAKPOINT)
+#define REMOTE_BREAKPOINT
+#endif
+
+#ifdef REMOTE_BREAKPOINT
+
+/* If the target isn't bi-endian, just pretend it is.  */
+#if !defined (LITTLE_REMOTE_BREAKPOINT) && !defined (BIG_REMOTE_BREAKPOINT)
+#define LITTLE_REMOTE_BREAKPOINT REMOTE_BREAKPOINT
+#define BIG_REMOTE_BREAKPOINT REMOTE_BREAKPOINT
+#endif
+
+static unsigned char big_break_insn[] = BIG_REMOTE_BREAKPOINT;
+static unsigned char little_break_insn[] = LITTLE_REMOTE_BREAKPOINT;
+
+#endif /* REMOTE_BREAKPOINT */
+
+/* Insert a breakpoint on targets that don't have any better breakpoint
+   support.  We read the contents of the target location and stash it,
+   then overwrite it with a breakpoint instruction.  ADDR is the target
+   location in the target machine.  CONTENTS_CACHE is a pointer to 
+   memory allocated for saving the target contents.  It is guaranteed
+   by the caller to be long enough to save sizeof BREAKPOINT bytes (this
+   is accomplished via BREAKPOINT_MAX).  */
+
+static int
+remote_insert_breakpoint (addr, contents_cache)
+     CORE_ADDR addr;
+     char *contents_cache;
+{
+#ifdef REMOTE_BREAKPOINT
+  int val;
+
+  val = target_read_memory (addr, contents_cache, sizeof big_break_insn);
+
+  if (val == 0)
+    {
+      if (TARGET_BYTE_ORDER == BIG_ENDIAN)
+	val = target_write_memory (addr, (char *) big_break_insn,
+				   sizeof big_break_insn);
+      else
+	val = target_write_memory (addr, (char *) little_break_insn,
+				   sizeof little_break_insn);
+    }
+
+  return val;
+#else
+  return memory_insert_breakpoint (addr, contents_cache);
+#endif /* REMOTE_BREAKPOINT */
+}
+
+static int
+remote_remove_breakpoint (addr, contents_cache)
+     CORE_ADDR addr;
+     char *contents_cache;
+{
+#ifdef REMOTE_BREAKPOINT
+  return target_write_memory (addr, contents_cache, sizeof big_break_insn);
+#else
+  return memory_remove_breakpoint (addr, contents_cache);
+#endif /* REMOTE_BREAKPOINT */
+}
+
+/* Some targets are only capable of doing downloads, and afterwards they switch
+   to the remote serial protocol.  This function provides a clean way to get
+   from the download target to the remote target.  It's basically just a
+   wrapper so that we don't have to expose any of the internal workings of
+   remote.c.
+
+   Prior to calling this routine, you should shutdown the current target code,
+   else you will get the "A program is being debugged already..." message.
+   Usually a call to pop_target() suffices.
+*/
+
+void
+push_remote_target (name, from_tty)
+     char *name;
+     int from_tty;
+{
+  printf_filtered ("Switching to remote protocol\n");
+  remote_open (name, from_tty);
+}
+
+/* Other targets want to use the entire remote serial module but with
+   certain remote_ops overridden. */
+
+void
+open_remote_target (name, from_tty, target, extended_p)
+     char *name;
+     int from_tty;
+     struct target_ops *target;
+     int extended_p;
+{
+  printf_filtered ("Selecting the %sremote protocol\n",
+		   (extended_p ? "extended-" : ""));
+  remote_open_1 (name, from_tty, target, extended_p);
+}
+
+/* Remote target communications for serial-line targets in custom GDB protocol
+   Copyright 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Remote communication protocol.
+
+   A debug packet whose contents are <data>
+   is encapsulated for transmission in the form:
+
+	$ <data> # CSUM1 CSUM2
+
+	<data> must be ASCII alphanumeric and cannot include characters
+	'$' or '#'.  If <data> starts with two characters followed by
+	':', then the existing stubs interpret this as a sequence number.
+
+	CSUM1 and CSUM2 are ascii hex representation of an 8-bit 
+	checksum of <data>, the most significant nibble is sent first.
+	the hex digits 0-9,a-f are used.
+
+   Receiver responds with:
+
+	+	- if CSUM is correct and ready for next packet
+	-	- if CSUM is incorrect
+
+   <data> is as follows:
+   Most values are encoded in ascii hex digits.  Signal numbers are according
+   to the numbering in target.h.
+
+	Request		Packet
+
+	set thread	Hct...		Set thread for subsequent operations.
+					c = 'c' for thread used in step and 
+					continue; t... can be -1 for all
+					threads.
+					c = 'g' for thread used in other
+					operations.  If zero, pick a thread,
+					any thread.
+	reply		OK		for success
+			ENN		for an error.
+
+	read registers  g
+	reply		XX....X		Each byte of register data
+					is described by two hex digits.
+					Registers are in the internal order
+					for GDB, and the bytes in a register
+					are in the same order the machine uses.
+			or ENN		for an error.
+
+	write regs	GXX..XX		Each byte of register data
+					is described by two hex digits.
+	reply		OK		for success
+			ENN		for an error
+
+        write reg	Pn...=r...	Write register n... with value r...,
+					which contains two hex digits for each
+					byte in the register (target byte
+					order).
+	reply		OK		for success
+			ENN		for an error
+	(not supported by all stubs).
+
+	read mem	mAA..AA,LLLL	AA..AA is address, LLLL is length.
+	reply		XX..XX		XX..XX is mem contents
+					Can be fewer bytes than requested
+					if able to read only part of the data.
+			or ENN		NN is errno
+
+	write mem	MAA..AA,LLLL:XX..XX
+					AA..AA is address,
+					LLLL is number of bytes,
+					XX..XX is data
+	reply		OK		for success
+			ENN		for an error (this includes the case
+					where only part of the data was
+					written).
+
+	continue	cAA..AA		AA..AA is address to resume
+					If AA..AA is omitted,
+					resume at same address.
+
+	step		sAA..AA		AA..AA is address to resume
+					If AA..AA is omitted,
+					resume at same address.
+
+	continue with	Csig;AA..AA	Continue with signal sig (hex signal
+	signal				number).  If ;AA..AA is omitted, resume
+					at same address.
+
+	step with	Ssig;AA..AA	Like 'C' but step not continue.
+	signal
+
+	last signal     ?               Reply the current reason for stopping.
+                                        This is the same reply as is generated
+					for step or cont : SAA where AA is the
+					signal number.
+
+	detach          D               Reply OK.
+
+	There is no immediate reply to step or cont.
+	The reply comes when the machine stops.
+	It is		SAA		AA is the signal number.
+
+	or...		TAAn...:r...;n...:r...;n...:r...;
+					AA = signal number
+					n... = register number (hex)
+					  r... = register contents
+					n... = `thread'
+					  r... = thread process ID.  This is
+						 a hex integer.
+					n... = other string not starting 
+					    with valid hex digit.
+					  gdb should ignore this n,r pair
+					  and go on to the next.  This way
+					  we can extend the protocol.
+	or...		WAA		The process exited, and AA is
+					the exit status.  This is only
+					applicable for certains sorts of
+					targets.
+	or...		XAA		The process terminated with signal
+					AA.
+        or...           OXX..XX	XX..XX  is hex encoding of ASCII data. This
+					can happen at any time while the program is
+					running and the debugger should
+					continue to wait for 'W', 'T', etc.
+
+	thread alive	TXX		Find out if the thread XX is alive.
+	reply		OK		thread is still alive
+			ENN		thread is dead
+	
+	remote restart	RXX		Restart the remote server
+
+	extended ops 	!		Use the extended remote protocol.
+					Sticky -- only needs to be set once.
+
+	kill request	k
+
+	toggle debug	d		toggle debug flag (see 386 & 68k stubs)
+	reset		r		reset -- see sparc stub.
+	reserved	<other>		On other requests, the stub should
+					ignore the request and send an empty
+					response ($#<checksum>).  This way
+					we can extend the protocol and GDB
+					can tell whether the stub it is
+					talking to uses the old or the new.
+	search		tAA:PP,MM	Search backwards starting at address
+					AA for a match with pattern PP and
+					mask MM.  PP and MM are 4 bytes.
+					Not supported by all stubs.
+
+	general query	qXXXX		Request info about XXXX.
+	general set	QXXXX=yyyy	Set value of XXXX to yyyy.
+	query sect offs	qOffsets	Get section offsets.  Reply is
+					Text=xxx;Data=yyy;Bss=zzz
+
+	Responses can be run-length encoded to save space.  A '*' means that
+	the next character is an ASCII encoding giving a repeat count which
+	stands for that many repititions of the character preceding the '*'.
+	The encoding is n+29, yielding a printable character where n >=3 
+	(which is where rle starts to win).  Don't use an n > 126.
+
+	So 
+	"0* " means the same as "0000".  */
+
+#include "defs.h"
+#include "gdb_string.h"
+#include <fcntl.h>
+#include "frame.h"
+#include "inferior.h"
+#include "bfd.h"
+#include "symfile.h"
+#include "target.h"
+#include "wait.h"
+/*#include "terminal.h"*/
+#include "gdbcmd.h"
+#include "objfiles.h"
+#include "gdb-stabs.h"
+#include "gdbthread.h"
+
+#include "dcache.h"
+
+#ifdef USG
+#include <sys/types.h>
+#endif
+
+#include <signal.h>
+#include "serial.h"
+
+/* Prototypes for local functions */
+
+static int remote_write_bytes PARAMS ((CORE_ADDR memaddr,
+				       char *myaddr, int len));
+
+static int remote_read_bytes PARAMS ((CORE_ADDR memaddr,
+				      char *myaddr, int len));
+
+static void remote_files_info PARAMS ((struct target_ops *ignore));
+
+static int remote_xfer_memory PARAMS ((CORE_ADDR memaddr, char *myaddr,
+				       int len, int should_write,
+				       struct target_ops *target));
+
+static void remote_prepare_to_store PARAMS ((void));
+
+static void remote_fetch_registers PARAMS ((int regno));
+
+static void remote_resume PARAMS ((int pid, int step,
+				   enum target_signal siggnal));
+
+static int remote_start_remote PARAMS ((char *dummy));
+
+static void remote_open PARAMS ((char *name, int from_tty));
+
+static void extended_remote_open PARAMS ((char *name, int from_tty));
+
+static void remote_open_1 PARAMS ((char *, int, struct target_ops *, int extended_p));
+
+static void remote_close PARAMS ((int quitting));
+
+static void remote_store_registers PARAMS ((int regno));
+
+static void remote_mourn PARAMS ((void));
+
+static void extended_remote_restart PARAMS ((void));
+
+static void extended_remote_mourn PARAMS ((void));
+
+static void extended_remote_create_inferior PARAMS ((char *, char *, char **));
+
+static void remote_mourn_1 PARAMS ((struct target_ops *));
+
+static void remote_send PARAMS ((char *buf));
+
+static int readchar PARAMS ((int timeout));
+
+static int remote_wait PARAMS ((int pid, struct target_waitstatus *status));
+
+static void remote_kill PARAMS ((void));
+
+static int tohex PARAMS ((int nib));
+
+static void remote_detach PARAMS ((char *args, int from_tty));
+
+static void remote_interrupt PARAMS ((int signo));
+
+static void remote_interrupt_twice PARAMS ((int signo));
+
+static void interrupt_query PARAMS ((void));
+
+static void set_thread PARAMS ((int, int));
+
+static int remote_thread_alive PARAMS ((int));
+
+static void get_offsets PARAMS ((void));
+
+static int read_frame PARAMS ((char *));
+
+static int remote_insert_breakpoint PARAMS ((CORE_ADDR, char *));
+
+static int remote_remove_breakpoint PARAMS ((CORE_ADDR, char *));
+
+static int hexnumlen PARAMS ((ULONGEST num));
+
+/* exported functions */
+
+extern int fromhex PARAMS ((int a));
+extern void getpkt PARAMS ((char *buf, int forever));
+extern int putpkt PARAMS ((char *buf));
+
+/* Define the target subroutine names */
+
+static struct target_ops remote_ops ;
+
+static void init_remote_ops(void)
+{
+  remote_ops.to_shortname =   "remote";		
+  remote_ops.to_longname =   "Remote serial target in gdb-specific protocol";
+  remote_ops.to_doc =   "Use a remote computer via a serial line; using a gdb-specific protocol.\n\
+Specify the serial device it is connected to (e.g. /dev/ttya)." ;  
+  remote_ops.to_open =   remote_open;		
+  remote_ops.to_close =   remote_close;		
+  remote_ops.to_attach =   NULL;		
+  remote_ops.to_detach =   remote_detach;	
+  remote_ops.to_resume =   remote_resume;	
+  remote_ops.to_wait  =   remote_wait;		
+  remote_ops.to_fetch_registers  =   remote_fetch_registers;
+  remote_ops.to_store_registers  =   remote_store_registers;
+  remote_ops.to_prepare_to_store =   remote_prepare_to_store;
+  remote_ops.to_xfer_memory  =   remote_xfer_memory;	
+  remote_ops.to_files_info  =   remote_files_info;	
+  remote_ops.to_insert_breakpoint =   remote_insert_breakpoint;
+  remote_ops.to_remove_breakpoint =   remote_remove_breakpoint;
+  remote_ops.to_terminal_init  =   NULL;		
+  remote_ops.to_terminal_inferior =   NULL;		
+  remote_ops.to_terminal_ours_for_output =   NULL;
+  remote_ops.to_terminal_ours  =   NULL;	
+  remote_ops.to_terminal_info  =   NULL;	
+  remote_ops.to_kill  =   remote_kill;		
+  remote_ops.to_load  =   generic_load;		
+  remote_ops.to_lookup_symbol =   NULL;		
+  remote_ops.to_create_inferior =   NULL;	
+  remote_ops.to_mourn_inferior =   remote_mourn;
+  remote_ops.to_can_run  =   0;			
+  remote_ops.to_notice_signals =   0;		
+  remote_ops.to_thread_alive  =   remote_thread_alive;
+  remote_ops.to_stop  =   0;		
+  remote_ops.to_stratum =   process_stratum;
+  remote_ops.DONT_USE =   NULL;		
+  remote_ops.to_has_all_memory =   1;	
+  remote_ops.to_has_memory =   1;	
+  remote_ops.to_has_stack =   1;	
+  remote_ops.to_has_registers =   1;	
+  remote_ops.to_has_execution =   1;	
+  remote_ops.to_sections =   NULL;	
+  remote_ops.to_sections_end =   NULL;	
+  remote_ops.to_magic =   OPS_MAGIC ;	
+} /* init_remote_ops */
+
+static struct target_ops extended_remote_ops ;
+
+static void init_extended_remote_ops(void) 
+{
+  extended_remote_ops.to_shortname =   "extended-remote";	
+  extended_remote_ops.to_longname =   "Extended remote serial target in gdb-specific protocol";
+  extended_remote_ops.to_doc =   "Use a remote computer via a serial line; using a gdb-specific protocol.\n\
+Specify the serial device it is connected to (e.g. /dev/ttya).",
+    extended_remote_ops.to_open =   extended_remote_open;	
+  extended_remote_ops.to_close =   remote_close;	
+  extended_remote_ops.to_attach =   NULL;		
+  extended_remote_ops.to_detach =   remote_detach;	
+  extended_remote_ops.to_resume =   remote_resume;	
+  extended_remote_ops.to_wait  =   remote_wait;		
+  extended_remote_ops.to_fetch_registers  =   remote_fetch_registers;
+  extended_remote_ops.to_store_registers  =   remote_store_registers;	
+  extended_remote_ops.to_prepare_to_store =   remote_prepare_to_store;
+  extended_remote_ops.to_xfer_memory  =   remote_xfer_memory;	
+  extended_remote_ops.to_files_info  =   remote_files_info;	
+  extended_remote_ops.to_insert_breakpoint =   remote_insert_breakpoint;
+  extended_remote_ops.to_remove_breakpoint =   remote_remove_breakpoint;
+  extended_remote_ops.to_terminal_init  =   NULL;		
+  extended_remote_ops.to_terminal_inferior =   NULL;		
+  extended_remote_ops.to_terminal_ours_for_output =   NULL;
+  extended_remote_ops.to_terminal_ours  =   NULL;	
+  extended_remote_ops.to_terminal_info  =   NULL;	
+  extended_remote_ops.to_kill  =   remote_kill;		
+  extended_remote_ops.to_load  =   generic_load;	
+  extended_remote_ops.to_lookup_symbol =   NULL;	
+  extended_remote_ops.to_create_inferior =   extended_remote_create_inferior;
+  extended_remote_ops.to_mourn_inferior =   extended_remote_mourn;
+  extended_remote_ops.to_can_run  =   0;			
+  extended_remote_ops.to_notice_signals =   0;			
+  extended_remote_ops.to_thread_alive  =   remote_thread_alive;
+  extended_remote_ops.to_stop  =   0;			
+  extended_remote_ops.to_stratum =   process_stratum;
+  extended_remote_ops.DONT_USE =   NULL;	
+  extended_remote_ops.to_has_all_memory =   1;	
+  extended_remote_ops.to_has_memory =   1;	
+  extended_remote_ops.to_has_stack =   1;	
+  extended_remote_ops.to_has_registers =   1;	
+  extended_remote_ops.to_has_execution =   1;	
+  extended_remote_ops.to_sections =   NULL;	
+  extended_remote_ops.to_sections_end =   NULL;
+  extended_remote_ops.to_magic =   OPS_MAGIC ;
+} 
+
+
+/* This was 5 seconds, which is a long time to sit and wait.
+   Unless this is going though some terminal server or multiplexer or
+   other form of hairy serial connection, I would think 2 seconds would
+   be plenty.  */
+
+/* Changed to allow option to set timeout value.
+   was static int remote_timeout = 2; */
+extern int remote_timeout;
+
+/* This variable chooses whether to send a ^C or a break when the user
+   requests program interruption.  Although ^C is usually what remote
+   systems expect, and that is the default here, sometimes a break is
+   preferable instead.  */
+
+static int remote_break;
+
+/* Descriptor for I/O to remote machine.  Initialize it to NULL so that
+   remote_open knows that we don't have a file open when the program
+   starts.  */
+static serial_t remote_desc = NULL;
+
+/* Having this larger than 400 causes us to be incompatible with m68k-stub.c
+   and i386-stub.c.  Normally, no one would notice because it only matters
+   for writing large chunks of memory (e.g. in downloads).  Also, this needs
+   to be more than 400 if required to hold the registers (see below, where
+   we round it up based on REGISTER_BYTES).  */
+#define	PBUFSIZ	400
+
+/* Maximum number of bytes to read/write at once.  The value here
+   is chosen to fill up a packet (the headers account for the 32).  */
+#define MAXBUFBYTES ((PBUFSIZ-32)/2)
+
+/* Round up PBUFSIZ to hold all the registers, at least.  */
+/* The blank line after the #if seems to be required to work around a
+   bug in HP's PA compiler.  */
+#if REGISTER_BYTES > MAXBUFBYTES
+
+#undef PBUFSIZ
+#define	PBUFSIZ	(REGISTER_BYTES * 2 + 32)
+#endif
+
+/* This variable sets the number of bytes to be written to the target
+   in a single packet.  Normally PBUFSIZ is satisfactory, but some
+   targets need smaller values (perhaps because the receiving end
+   is slow).  */
+
+static int remote_write_size = PBUFSIZ;
+
+/* This is the size (in chars) of the first response to the `g' command.  This
+   is used to limit the size of the memory read and write commands to prevent
+   stub buffers from overflowing.  The size does not include headers and
+   trailers, it is only the payload size. */
+
+static int remote_register_buf_size = 0;
+
+/* Should we try the 'P' request?  If this is set to one when the stub
+   doesn't support 'P', the only consequence is some unnecessary traffic.  */
+static int stub_supports_P = 1;
+
+/* These are pointers to hook functions that may be set in order to
+   modify resume/wait behavior for a particular architecture.  */
+
+void (*target_resume_hook) PARAMS ((void));
+void (*target_wait_loop_hook) PARAMS ((void));
+
+
+/* These are the threads which we last sent to the remote system.  -1 for all
+   or -2 for not sent yet.  */
+int general_thread;
+int cont_thread;
+
+static void
+set_thread (th, gen)
+     int th;
+     int gen;
+{
+  char buf[PBUFSIZ];
+  int state = gen ? general_thread : cont_thread;
+  if (state == th)
+    return;
+  buf[0] = 'H';
+  buf[1] = gen ? 'g' : 'c';
+  if (th == 42000)
+    {
+      buf[2] = '0';
+      buf[3] = '\0';
+    }
+  else if (th < 0)
+    sprintf (&buf[2], "-%x", -th);
+  else
+    sprintf (&buf[2], "%x", th);
+  putpkt (buf);
+  getpkt (buf, 0);
+  if (gen)
+    general_thread = th;
+  else
+    cont_thread = th;
+}
+
+/*  Return nonzero if the thread TH is still alive on the remote system.  */
+
+static int
+remote_thread_alive (th)
+     int th;
+{
+  char buf[PBUFSIZ];
+
+  buf[0] = 'T';
+  if (th < 0)
+    sprintf (&buf[1], "-%x", -th);
+  else
+    sprintf (&buf[1], "%x", th);
+  putpkt (buf);
+  getpkt (buf, 0);
+  return (buf[0] == 'O' && buf[1] == 'K');
+}
+
+/*  Restart the remote side; this is an extended protocol operation.  */
+
+static void
+extended_remote_restart ()
+{
+  char buf[PBUFSIZ];
+
+  /* Send the restart command; for reasons I don't understand the
+     remote side really expects a number after the "R".  */
+  buf[0] = 'R';
+  sprintf (&buf[1], "%x", 0);
+  putpkt (buf);
+
+  /* Now query for status so this looks just like we restarted
+     gdbserver from scratch.  */
+  putpkt ("?");
+  getpkt (buf, 0);
+}
+
+/* Clean up connection to a remote debugger.  */
+
+/* ARGSUSED */
+static void
+remote_close (quitting)
+     int quitting;
+{
+  if (remote_desc)
+    SERIAL_CLOSE (remote_desc);
+  remote_desc = NULL;
+}
+
+/* Query the remote side for the text, data and bss offsets. */
+
+static void
+get_offsets ()
+{
+  char buf[PBUFSIZ], *ptr;
+  int lose;
+  CORE_ADDR text_addr, data_addr, bss_addr;
+  struct section_offsets *offs;
+
+  putpkt ("qOffsets");
+
+  getpkt (buf, 0);
+
+  if (buf[0] == '\000')
+    return;			/* Return silently.  Stub doesn't support this
+				   command. */
+  if (buf[0] == 'E')
+    {
+      warning ("Remote failure reply: %s", buf);
+      return;
+    }
+
+  /* Pick up each field in turn.  This used to be done with scanf, but
+     scanf will make trouble if CORE_ADDR size doesn't match
+     conversion directives correctly.  The following code will work
+     with any size of CORE_ADDR.  */
+  text_addr = data_addr = bss_addr = 0;
+  ptr = buf;
+  lose = 0;
+
+  if (strncmp (ptr, "Text=", 5) == 0)
+    {
+      ptr += 5;
+      /* Don't use strtol, could lose on big values.  */
+      while (*ptr && *ptr != ';')
+	text_addr = (text_addr << 4) + fromhex (*ptr++);
+    }
+  else
+    lose = 1;
+
+  if (!lose && strncmp (ptr, ";Data=", 6) == 0)
+    {
+      ptr += 6;
+      while (*ptr && *ptr != ';')
+	data_addr = (data_addr << 4) + fromhex (*ptr++);
+    }
+  else
+    lose = 1;
+
+  if (!lose && strncmp (ptr, ";Bss=", 5) == 0)
+    {
+      ptr += 5;
+      while (*ptr && *ptr != ';')
+	bss_addr = (bss_addr << 4) + fromhex (*ptr++);
+    }
+  else
+    lose = 1;
+
+  if (lose)
+    error ("Malformed response to offset query, %s", buf);
+
+  if (symfile_objfile == NULL)
+    return;
+
+  offs = (struct section_offsets *) alloca (sizeof (struct section_offsets)
+					    + symfile_objfile->num_sections
+					    * sizeof (offs->offsets));
+  memcpy (offs, symfile_objfile->section_offsets,
+	  sizeof (struct section_offsets)
+	  + symfile_objfile->num_sections
+	  * sizeof (offs->offsets));
+
+  ANOFFSET (offs, SECT_OFF_TEXT) = text_addr;
+
+  /* This is a temporary kludge to force data and bss to use the same offsets
+     because that's what nlmconv does now.  The real solution requires changes
+     to the stub and remote.c that I don't have time to do right now.  */
+
+  ANOFFSET (offs, SECT_OFF_DATA) = data_addr;
+  ANOFFSET (offs, SECT_OFF_BSS) = data_addr;
+
+  objfile_relocate (symfile_objfile, offs);
+}
+
+/* Stub for catch_errors.  */
+
+static int
+remote_start_remote (dummy)
+     char *dummy;
+{
+  immediate_quit = 1;		/* Allow user to interrupt it */
+
+  /* Ack any packet which the remote side has already sent.  */
+  SERIAL_WRITE (remote_desc, "+", 1);
+
+  /* Let the stub know that we want it to return the thread.  */
+  set_thread (-1, 0);
+
+  get_offsets ();		/* Get text, data & bss offsets */
+
+  putpkt ("?");			/* initiate a query from remote machine */
+  immediate_quit = 0;
+
+  start_remote ();		/* Initialize gdb process mechanisms */
+  return 1;
+}
+
+/* Open a connection to a remote debugger.
+   NAME is the filename used for communication.  */
+
+static void
+remote_open (name, from_tty)
+     char *name;
+     int from_tty;
+{
+  remote_open_1 (name, from_tty, &remote_ops, 0);
+}
+
+/* Open a connection to a remote debugger using the extended
+   remote gdb protocol.  NAME is the filename used for communication.  */
+
+static void
+extended_remote_open (name, from_tty)
+     char *name;
+     int from_tty;
+{
+  remote_open_1 (name, from_tty, &extended_remote_ops, 1/*extended_p*/);
+}
+
+/* Generic code for opening a connection to a remote target.  */
+static DCACHE *remote_dcache;
+
+static void
+remote_open_1 (name, from_tty, target, extended_p)
+     char *name;
+     int from_tty;
+     struct target_ops *target;
+     int extended_p;
+{
+  if (name == 0)
+    error ("To open a remote debug connection, you need to specify what serial\n\
+device is attached to the remote system (e.g. /dev/ttya).");
+
+  target_preopen (from_tty);
+
+  unpush_target (target);
+
+  remote_dcache = dcache_init (remote_read_bytes, remote_write_bytes);
+
+  remote_desc = SERIAL_OPEN (name);
+  if (!remote_desc)
+    perror_with_name (name);
+
+  if (baud_rate != -1)
+    {
+      if (SERIAL_SETBAUDRATE (remote_desc, baud_rate))
+	{
+	  SERIAL_CLOSE (remote_desc);
+	  perror_with_name (name);
+	}
+    }
+
+
+  SERIAL_RAW (remote_desc);
+
+  /* If there is something sitting in the buffer we might take it as a
+     response to a command, which would be bad.  */
+  SERIAL_FLUSH_INPUT (remote_desc);
+
+  if (from_tty)
+    {
+      puts_filtered ("Remote debugging using ");
+      puts_filtered (name);
+      puts_filtered ("\n");
+    }
+  push_target (target);	/* Switch to using remote target now */
+
+  /* Start out by trying the 'P' request to set registers.  We set this each
+     time that we open a new target so that if the user switches from one
+     stub to another, we can (if the target is closed and reopened) cope.  */
+  stub_supports_P = 1;
+
+  general_thread = -2;
+  cont_thread = -2;
+
+  /* Without this, some commands which require an active target (such as kill)
+     won't work.  This variable serves (at least) double duty as both the pid
+     of the target process (if it has such), and as a flag indicating that a
+     target is active.  These functions should be split out into seperate
+     variables, especially since GDB will someday have a notion of debugging
+     several processes.  */
+
+  inferior_pid = 42000;
+  /* Start the remote connection; if error (0), discard this target.
+     In particular, if the user quits, be sure to discard it
+     (we'd be in an inconsistent state otherwise).  */
+  if (!catch_errors (remote_start_remote, (char *)0, 
+		     "Couldn't establish connection to remote target\n", RETURN_MASK_ALL))
+    {
+      pop_target();
+      return;
+    }
+
+  if (extended_p)
+    {
+      /* tell the remote that we're using the extended protocol.  */
+      char buf[PBUFSIZ];
+      putpkt ("!");
+      getpkt (buf, 0);
+    }
+}
+
+/* This takes a program previously attached to and detaches it.  After
+   this is done, GDB can be used to debug some other program.  We
+   better not have left any breakpoints in the target program or it'll
+   die when it hits one.  */
+
+static void
+remote_detach (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  char buf[PBUFSIZ];
+
+  if (args)
+    error ("Argument given to \"detach\" when remotely debugging.");
+
+  /* Tell the remote target to detach.  */
+  strcpy (buf, "D");
+  remote_send (buf);
+
+  pop_target ();
+  if (from_tty)
+    puts_filtered ("Ending remote debugging.\n");
+}
+
+/* Convert hex digit A to a number.  */
+
+int
+fromhex (a)
+     int a;
+{
+  if (a >= '0' && a <= '9')
+    return a - '0';
+  else if (a >= 'a' && a <= 'f')
+    return a - 'a' + 10;
+  else if (a >= 'A' && a <= 'F')
+    return a - 'A' + 10;
+  else 
+    error ("Reply contains invalid hex digit %d", a);
+}
+
+/* Convert number NIB to a hex digit.  */
+
+static int
+tohex (nib)
+     int nib;
+{
+  if (nib < 10)
+    return '0'+nib;
+  else
+    return 'a'+nib-10;
+}
+
+/* Tell the remote machine to resume.  */
+
+static enum target_signal last_sent_signal = TARGET_SIGNAL_0;
+int last_sent_step;
+
+static void
+remote_resume (pid, step, siggnal)
+     int pid, step;
+     enum target_signal siggnal;
+{
+  char buf[PBUFSIZ];
+
+  if (pid == -1)
+    set_thread (inferior_pid, 0);
+  else
+    set_thread (pid, 0);
+
+  dcache_flush (remote_dcache);
+
+  last_sent_signal = siggnal;
+  last_sent_step = step;
+
+  /* A hook for when we need to do something at the last moment before
+     resumption.  */
+  if (target_resume_hook)
+    (*target_resume_hook) ();
+
+  if (siggnal != TARGET_SIGNAL_0)
+    {
+      buf[0] = step ? 'S' : 'C';
+      buf[1] = tohex (((int)siggnal >> 4) & 0xf);
+      buf[2] = tohex ((int)siggnal & 0xf);
+      buf[3] = '\0';
+    }
+  else
+    strcpy (buf, step ? "s": "c");
+
+  putpkt (buf);
+}
+
+/* Send ^C to target to halt it.  Target will respond, and send us a
+   packet.  */
+
+static void
+remote_interrupt (signo)
+     int signo;
+{
+  /* If this doesn't work, try more severe steps.  */
+  signal (signo, remote_interrupt_twice);
+  
+  if (remote_debug)
+    printf_unfiltered ("remote_interrupt called\n");
+
+  /* Send a break or a ^C, depending on user preference.  */
+  if (remote_break)
+    SERIAL_SEND_BREAK (remote_desc);
+  else
+    SERIAL_WRITE (remote_desc, "\003", 1);
+}
+
+static void (*ofunc)();
+
+/* The user typed ^C twice.  */
+static void
+remote_interrupt_twice (signo)
+     int signo;
+{
+  signal (signo, ofunc);
+  
+  interrupt_query ();
+
+  signal (signo, remote_interrupt);
+}
+
+/* Ask the user what to do when an interrupt is received.  */
+
+static void
+interrupt_query ()
+{
+  target_terminal_ours ();
+
+  if (query ("Interrupted while waiting for the program.\n\
+Give up (and stop debugging it)? "))
+    {
+      target_mourn_inferior ();
+      return_to_top_level (RETURN_QUIT);
+    }
+
+  target_terminal_inferior ();
+}
+
+/* If nonzero, ignore the next kill.  */
+int kill_kludge;
+
+void
+remote_console_output (msg)
+     char *msg;
+{
+  char *p;
+
+  for (p = msg; *p; p +=2) 
+    {
+      char tb[2];
+      char c = fromhex (p[0]) * 16 + fromhex (p[1]);
+      tb[0] = c;
+      tb[1] = 0;
+      if (target_output_hook)
+	target_output_hook (tb);
+      else 
+	fputs_filtered (tb, gdb_stdout);
+    }
+}
+
+/* Wait until the remote machine stops, then return,
+   storing status in STATUS just as `wait' would.
+   Returns "pid" (though it's not clear what, if anything, that
+   means in the case of this target).  */
+
+static int
+remote_wait (pid, status)
+     int pid;
+     struct target_waitstatus *status;
+{
+  unsigned char buf[PBUFSIZ];
+  int thread_num = -1;
+
+  status->kind = TARGET_WAITKIND_EXITED;
+  status->value.integer = 0;
+
+  while (1)
+    {
+      unsigned char *p;
+
+      ofunc = (void (*)()) signal (SIGINT, remote_interrupt);
+      getpkt ((char *) buf, 1);
+      signal (SIGINT, ofunc);
+
+      /* This is a hook for when we need to do something (perhaps the
+	 collection of trace data) every time the target stops.  */
+      if (target_wait_loop_hook)
+	(*target_wait_loop_hook) ();
+
+      switch (buf[0])
+	{
+	case 'E':		/* Error of some sort */
+	  warning ("Remote failure reply: %s", buf);
+	  continue;
+	case 'T':		/* Status with PC, SP, FP, ... */
+	  {
+	    int i;
+	    long regno;
+	    char regs[MAX_REGISTER_RAW_SIZE];
+
+	    /* Expedited reply, containing Signal, {regno, reg} repeat */
+	    /*  format is:  'Tssn...:r...;n...:r...;n...:r...;#cc', where
+		ss = signal number
+		n... = register number
+		r... = register contents
+		*/
+	    p = &buf[3];	/* after Txx */
+
+	    while (*p)
+	      {
+		unsigned char *p1;
+		char *p_temp;
+
+		regno = strtol ((const char *) p, &p_temp, 16); /* Read the register number */
+		p1 = (unsigned char *)p_temp;
+
+		if (p1 == p)
+		  {
+		    p1 = (unsigned char *) strchr ((const char *) p, ':');
+		    if (p1 == NULL)
+		      warning ("Malformed packet (missing colon): %s\n\
+Packet: '%s'\n",
+			       p, buf);
+		    if (strncmp ((const char *) p, "thread", p1 - p) == 0)
+		      {
+			thread_num = strtol ((const char *) ++p1, &p_temp, 16);
+			p = (unsigned char *)p_temp;
+		      }
+		  }
+		else
+		  {
+		    p = p1;
+
+		    if (*p++ != ':')
+		      warning ("Malformed packet (missing colon): %s\n\
+Packet: '%s'\n",
+			       p, buf);
+
+		    if (regno >= NUM_REGS)
+		      warning ("Remote sent bad register number %ld: %s\n\
+Packet: '%s'\n",
+			       regno, p, buf);
+
+		    for (i = 0; i < REGISTER_RAW_SIZE (regno); i++)
+		      {
+			if (p[0] == 0 || p[1] == 0)
+			  warning ("Remote reply is too short: %s", buf);
+			regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+			p += 2;
+		      }
+		    supply_register (regno, regs);
+		  }
+
+		if (*p++ != ';')
+		  warning ("Remote register badly formatted: %s", buf);
+	      }
+	  }
+	  /* fall through */
+	case 'S':		/* Old style status, just signal only */
+	  status->kind = TARGET_WAITKIND_STOPPED;
+	  status->value.sig = (enum target_signal)
+	    (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
+
+	  goto got_status;
+	case 'W':		/* Target exited */
+	  {
+	    /* The remote process exited.  */
+	    status->kind = TARGET_WAITKIND_EXITED;
+	    status->value.integer = (fromhex (buf[1]) << 4) + fromhex (buf[2]);
+	    goto got_status;
+	  }
+	case 'X':
+	  status->kind = TARGET_WAITKIND_SIGNALLED;
+	  status->value.sig = (enum target_signal)
+	    (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
+	  kill_kludge = 1;
+
+	  goto got_status;
+	case 'O':		/* Console output */
+	  remote_console_output (buf + 1);
+	  continue;
+	case '\0':
+	  if (last_sent_signal != TARGET_SIGNAL_0)
+	    {
+	      /* Zero length reply means that we tried 'S' or 'C' and
+		 the remote system doesn't support it.  */
+	      target_terminal_ours_for_output ();
+	      printf_filtered
+		("Can't send signals to this remote system.  %s not sent.\n",
+		 target_signal_to_name (last_sent_signal));
+	      last_sent_signal = TARGET_SIGNAL_0;
+	      target_terminal_inferior ();
+
+	      strcpy ((char *) buf, last_sent_step ? "s" : "c");
+	      putpkt ((char *) buf);
+	      continue;
+	    }
+	  /* else fallthrough */
+	default:
+	  warning ("Invalid remote reply: %s", buf);
+	  continue;
+	}
+    }
+ got_status:
+  if (thread_num != -1)
+    {
+      /* Initial thread value can only be acquired via wait, so deal with
+	 this marker which is used before the first thread value is
+	 acquired.  */
+      if (inferior_pid == 42000)
+	{
+	  inferior_pid = thread_num;
+	  add_thread (inferior_pid);
+	}
+      return thread_num;
+    }
+  return inferior_pid;
+}
+
+/* Number of bytes of registers this stub implements.  */
+static int register_bytes_found;
+
+/* Read the remote registers into the block REGS.  */
+/* Currently we just read all the registers, so we don't use regno.  */
+/* ARGSUSED */
+static void
+remote_fetch_registers (regno)
+     int regno;
+{
+  char buf[PBUFSIZ];
+  int i;
+  char *p;
+  char regs[REGISTER_BYTES];
+
+  set_thread (inferior_pid, 1);
+
+  sprintf (buf, "g");
+  remote_send (buf);
+
+  if (remote_register_buf_size == 0)
+    remote_register_buf_size = strlen (buf);
+
+  /* Unimplemented registers read as all bits zero.  */
+  memset (regs, 0, REGISTER_BYTES);
+
+  /* We can get out of synch in various cases.  If the first character
+     in the buffer is not a hex character, assume that has happened
+     and try to fetch another packet to read.  */
+  while ((buf[0] < '0' || buf[0] > '9')
+	 && (buf[0] < 'a' || buf[0] > 'f'))
+    {
+      if (remote_debug)
+	printf_unfiltered ("Bad register packet; fetching a new packet\n");
+      getpkt (buf, 0);
+    }
+
+  /* Reply describes registers byte by byte, each byte encoded as two
+     hex characters.  Suck them all up, then supply them to the
+     register cacheing/storage mechanism.  */
+
+  p = buf;
+  for (i = 0; i < REGISTER_BYTES; i++)
+    {
+      if (p[0] == 0)
+	break;
+      if (p[1] == 0)
+	{
+	  warning ("Remote reply is of odd length: %s", buf);
+	  /* Don't change register_bytes_found in this case, and don't
+	     print a second warning.  */
+	  goto supply_them;
+	}
+      regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+      p += 2;
+    }
+
+  if (i != register_bytes_found)
+    {
+      register_bytes_found = i;
+#ifdef REGISTER_BYTES_OK
+      if (!REGISTER_BYTES_OK (i))
+	warning ("Remote reply is too short: %s", buf);
+#endif
+    }
+
+ supply_them:
+  for (i = 0; i < NUM_REGS; i++)
+    supply_register (i, &regs[REGISTER_BYTE(i)]);
+}
+
+/* Prepare to store registers.  Since we may send them all (using a
+   'G' request), we have to read out the ones we don't want to change
+   first.  */
+
+static void 
+remote_prepare_to_store ()
+{
+  /* Make sure the entire registers array is valid.  */
+  read_register_bytes (0, (char *)NULL, REGISTER_BYTES);
+}
+
+/* Store register REGNO, or all registers if REGNO == -1, from the contents
+   of REGISTERS.  FIXME: ignores errors.  */
+
+static void
+remote_store_registers (regno)
+     int regno;
+{
+  char buf[PBUFSIZ];
+  int i;
+  char *p;
+
+  set_thread (inferior_pid, 1);
+
+  if (regno >= 0 && stub_supports_P)
+    {
+      /* Try storing a single register.  */
+      char *regp;
+
+      sprintf (buf, "P%x=", regno);
+      p = buf + strlen (buf);
+      regp = &registers[REGISTER_BYTE (regno)];
+      for (i = 0; i < REGISTER_RAW_SIZE (regno); ++i)
+	{
+	  *p++ = tohex ((regp[i] >> 4) & 0xf);
+	  *p++ = tohex (regp[i] & 0xf);
+	}
+      *p = '\0';
+      remote_send (buf);
+      if (buf[0] != '\0')
+	{
+	  /* The stub understands the 'P' request.  We are done.  */
+	  return;
+	}
+
+      /* The stub does not support the 'P' request.  Use 'G' instead,
+	 and don't try using 'P' in the future (it will just waste our
+	 time).  */
+      stub_supports_P = 0;
+    }
+
+  buf[0] = 'G';
+
+  /* Command describes registers byte by byte,
+     each byte encoded as two hex characters.  */
+
+  p = buf + 1;
+  /* remote_prepare_to_store insures that register_bytes_found gets set.  */
+  for (i = 0; i < register_bytes_found; i++)
+    {
+      *p++ = tohex ((registers[i] >> 4) & 0xf);
+      *p++ = tohex (registers[i] & 0xf);
+    }
+  *p = '\0';
+
+  remote_send (buf);
+}
+
+/* 
+   Use of the data cache *used* to be disabled because it loses for looking at
+   and changing hardware I/O ports and the like.  Accepting `volatile'
+   would perhaps be one way to fix it.  Another idea would be to use the
+   executable file for the text segment (for all SEC_CODE sections?
+   For all SEC_READONLY sections?).  This has problems if you want to
+   actually see what the memory contains (e.g. self-modifying code,
+   clobbered memory, user downloaded the wrong thing).  
+
+   Because it speeds so much up, it's now enabled, if you're playing
+   with registers you turn it of (set remotecache 0)
+*/
+
+/* Read a word from remote address ADDR and return it.
+   This goes through the data cache.  */
+
+#if 0	/* unused? */
+static int
+remote_fetch_word (addr)
+     CORE_ADDR addr;
+{
+  return dcache_fetch (remote_dcache, addr);
+}
+
+/* Write a word WORD into remote address ADDR.
+   This goes through the data cache.  */
+
+static void
+remote_store_word (addr, word)
+     CORE_ADDR addr;
+     int word;
+{
+  dcache_poke (remote_dcache, addr, word);
+}
+#endif	/* 0 (unused?) */
+
+
+
+/* Return the number of hex digits in num.  */
+
+static int
+hexnumlen (num)
+     ULONGEST num;
+{
+  int i;
+
+  for (i = 0; num != 0; i++)
+    num >>= 4;
+
+  return max (i, 1);
+}
+
+/* Write memory data directly to the remote machine.
+   This does not inform the data cache; the data cache uses this.
+   MEMADDR is the address in the remote memory space.
+   MYADDR is the address of the buffer in our space.
+   LEN is the number of bytes.
+
+   Returns number of bytes transferred, or 0 for error.  */
+
+static int
+remote_write_bytes (memaddr, myaddr, len)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+{
+  int max_buf_size;		/* Max size of packet output buffer */
+  int origlen;
+
+  /* Chop the transfer down if necessary */
+
+  max_buf_size = min (remote_write_size, PBUFSIZ);
+  if (remote_register_buf_size != 0)
+    max_buf_size = min (max_buf_size, remote_register_buf_size);
+
+  /* Subtract header overhead from max payload size -  $M<memaddr>,<len>:#nn */
+  max_buf_size -= 2 + hexnumlen (memaddr + len - 1) + 1 + hexnumlen (len) + 4;
+
+  origlen = len;
+  while (len > 0)
+    {
+      char buf[PBUFSIZ];
+      char *p;
+      int todo;
+      int i;
+
+      todo = min (len, max_buf_size / 2); /* num bytes that will fit */
+
+      /* FIXME-32x64: Need a version of print_address_numeric which puts the
+	 result in a buffer like sprintf.  */
+      sprintf (buf, "M%lx,%x:", (unsigned long) memaddr, todo);
+
+      /* We send target system values byte by byte, in increasing byte addresses,
+	 each byte encoded as two hex characters.  */
+
+      p = buf + strlen (buf);
+      for (i = 0; i < todo; i++)
+	{
+	  *p++ = tohex ((myaddr[i] >> 4) & 0xf);
+	  *p++ = tohex (myaddr[i] & 0xf);
+	}
+      *p = '\0';
+
+      putpkt (buf);
+      getpkt (buf, 0);
+
+      if (buf[0] == 'E')
+	{
+	  /* There is no correspondance between what the remote protocol uses
+	     for errors and errno codes.  We would like a cleaner way of
+	     representing errors (big enough to include errno codes, bfd_error
+	     codes, and others).  But for now just return EIO.  */
+	  errno = EIO;
+	  return 0;
+	}
+      myaddr += todo;
+      memaddr += todo;
+      len -= todo;
+    }
+  return origlen;
+}
+
+/* Read memory data directly from the remote machine.
+   This does not use the data cache; the data cache uses this.
+   MEMADDR is the address in the remote memory space.
+   MYADDR is the address of the buffer in our space.
+   LEN is the number of bytes.
+
+   Returns number of bytes transferred, or 0 for error.  */
+
+static int
+remote_read_bytes (memaddr, myaddr, len)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+{
+  int max_buf_size;		/* Max size of packet output buffer */
+  int origlen;
+
+  /* Chop the transfer down if necessary */
+
+  max_buf_size = min (remote_write_size, PBUFSIZ);
+  if (remote_register_buf_size != 0)
+    max_buf_size = min (max_buf_size, remote_register_buf_size);
+
+  origlen = len;
+  while (len > 0)
+    {
+      char buf[PBUFSIZ];
+      char *p;
+      int todo;
+      int i;
+
+      todo = min (len, max_buf_size / 2); /* num bytes that will fit */
+
+      /* FIXME-32x64: Need a version of print_address_numeric which puts the
+	 result in a buffer like sprintf.  */
+      sprintf (buf, "m%lx,%x", (unsigned long) memaddr, todo);
+      putpkt (buf);
+      getpkt (buf, 0);
+
+      if (buf[0] == 'E')
+	{
+	  /* There is no correspondance between what the remote protocol uses
+	     for errors and errno codes.  We would like a cleaner way of
+	     representing errors (big enough to include errno codes, bfd_error
+	     codes, and others).  But for now just return EIO.  */
+	  errno = EIO;
+	  return 0;
+	}
+
+  /* Reply describes memory byte by byte,
+     each byte encoded as two hex characters.  */
+
+      p = buf;
+      for (i = 0; i < todo; i++)
+	{
+	  if (p[0] == 0 || p[1] == 0)
+	    /* Reply is short.  This means that we were able to read only part
+	       of what we wanted to.  */
+	    return i + (origlen - len);
+	  myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+	  p += 2;
+	}
+      myaddr += todo;
+      memaddr += todo;
+      len -= todo;
+    }
+  return origlen;
+}
+
+/* Read or write LEN bytes from inferior memory at MEMADDR, transferring
+   to or from debugger address MYADDR.  Write to inferior if SHOULD_WRITE is
+   nonzero.  Returns length of data written or read; 0 for error.  */
+
+/* ARGSUSED */
+static int
+remote_xfer_memory(memaddr, myaddr, len, should_write, target)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+     int should_write;
+     struct target_ops *target;			/* ignored */
+{
+#ifdef REMOTE_TRANSLATE_XFER_ADDRESS
+  CORE_ADDR targaddr;
+  int targlen;
+  REMOTE_TRANSLATE_XFER_ADDRESS (memaddr, len, targaddr, targlen);
+  if (targlen == 0)
+    return 0;
+  memaddr = targaddr;
+  len = targlen;
+#endif
+
+  return dcache_xfer_memory (remote_dcache, memaddr, myaddr, len, should_write);
+}
+
+   
+#if 0
+/* Enable after 4.12.  */
+
+void
+remote_search (len, data, mask, startaddr, increment, lorange, hirange
+	       addr_found, data_found)
+     int len;
+     char *data;
+     char *mask;
+     CORE_ADDR startaddr;
+     int increment;
+     CORE_ADDR lorange;
+     CORE_ADDR hirange;
+     CORE_ADDR *addr_found;
+     char *data_found;
+{
+  if (increment == -4 && len == 4)
+    {
+      long mask_long, data_long;
+      long data_found_long;
+      CORE_ADDR addr_we_found;
+      char buf[PBUFSIZ];
+      long returned_long[2];
+      char *p;
+
+      mask_long = extract_unsigned_integer (mask, len);
+      data_long = extract_unsigned_integer (data, len);
+      sprintf (buf, "t%x:%x,%x", startaddr, data_long, mask_long);
+      putpkt (buf);
+      getpkt (buf, 0);
+      if (buf[0] == '\0')
+	{
+	  /* The stub doesn't support the 't' request.  We might want to
+	     remember this fact, but on the other hand the stub could be
+	     switched on us.  Maybe we should remember it only until
+	     the next "target remote".  */
+	  generic_search (len, data, mask, startaddr, increment, lorange,
+			  hirange, addr_found, data_found);
+	  return;
+	}
+
+      if (buf[0] == 'E')
+	/* There is no correspondance between what the remote protocol uses
+	   for errors and errno codes.  We would like a cleaner way of
+	   representing errors (big enough to include errno codes, bfd_error
+	   codes, and others).  But for now just use EIO.  */
+	memory_error (EIO, startaddr);
+      p = buf;
+      addr_we_found = 0;
+      while (*p != '\0' && *p != ',')
+	addr_we_found = (addr_we_found << 4) + fromhex (*p++);
+      if (*p == '\0')
+	error ("Protocol error: short return for search");
+
+      data_found_long = 0;
+      while (*p != '\0' && *p != ',')
+	data_found_long = (data_found_long << 4) + fromhex (*p++);
+      /* Ignore anything after this comma, for future extensions.  */
+
+      if (addr_we_found < lorange || addr_we_found >= hirange)
+	{
+	  *addr_found = 0;
+	  return;
+	}
+
+      *addr_found = addr_we_found;
+      *data_found = store_unsigned_integer (data_we_found, len);
+      return;
+    }
+  generic_search (len, data, mask, startaddr, increment, lorange,
+		  hirange, addr_found, data_found);
+}
+#endif /* 0 */
+
+static void
+remote_files_info (ignore)
+     struct target_ops *ignore;
+{
+  puts_filtered ("Debugging a target over a serial line.\n");
+}
+
+/* Stuff for dealing with the packets which are part of this protocol.
+   See comment at top of file for details.  */
+
+/* Read a single character from the remote end, masking it down to 7 bits. */
+
+static int
+readchar (timeout)
+     int timeout;
+{
+  int ch;
+
+  ch = SERIAL_READCHAR (remote_desc, timeout);
+
+  switch (ch)
+    {
+    case SERIAL_EOF:
+      error ("Remote connection closed");
+    case SERIAL_ERROR:
+      perror_with_name ("Remote communication error");
+    case SERIAL_TIMEOUT:
+      return ch;
+    default:
+      return ch & 0x7f;
+    }
+}
+
+/* Send the command in BUF to the remote machine,
+   and read the reply into BUF.
+   Report an error if we get an error reply.  */
+
+static void
+remote_send (buf)
+     char *buf;
+{
+  putpkt (buf);
+  getpkt (buf, 0);
+
+  if (buf[0] == 'E')
+    error ("Remote failure reply: %s", buf);
+}
+
+/* Send a packet to the remote machine, with error checking.
+   The data of the packet is in BUF.  */
+
+int
+putpkt (buf)
+     char *buf;
+{
+  int i;
+  unsigned char csum = 0;
+  char buf2[PBUFSIZ];
+  int cnt = strlen (buf);
+  int ch;
+  int tcount = 0;
+  char *p;
+
+  /* Copy the packet into buffer BUF2, encapsulating it
+     and giving it a checksum.  */
+
+  if (cnt > (int) sizeof (buf2) - 5)		/* Prosanity check */
+    abort();
+
+  p = buf2;
+  *p++ = '$';
+
+  for (i = 0; i < cnt; i++)
+    {
+      csum += buf[i];
+      *p++ = buf[i];
+    }
+  *p++ = '#';
+  *p++ = tohex ((csum >> 4) & 0xf);
+  *p++ = tohex (csum & 0xf);
+
+  /* Send it over and over until we get a positive ack.  */
+
+  while (1)
+    {
+      int started_error_output = 0;
+
+      if (remote_debug)
+	{
+	  *p = '\0';
+	  printf_unfiltered ("Sending packet: %s...", buf2);
+	  gdb_flush(gdb_stdout);
+	}
+      if (SERIAL_WRITE (remote_desc, buf2, p - buf2))
+	perror_with_name ("putpkt: write failed");
+
+      /* read until either a timeout occurs (-2) or '+' is read */
+      while (1)
+	{
+	  ch = readchar (remote_timeout);
+
+ 	  if (remote_debug)
+	    {
+	      switch (ch)
+		{
+		case '+':
+		case SERIAL_TIMEOUT:
+		case '$':
+		  if (started_error_output)
+		    {
+		      putchar_unfiltered ('\n');
+		      started_error_output = 0;
+		    }
+		}
+	    }
+
+	  switch (ch)
+	    {
+	    case '+':
+	      if (remote_debug)
+		printf_unfiltered("Ack\n");
+	      return 1;
+	    case SERIAL_TIMEOUT:
+	      tcount ++;
+	      if (tcount > 3)
+		return 0;
+	      break;		/* Retransmit buffer */
+	    case '$':
+	      {
+		char junkbuf[PBUFSIZ];
 
+	      /* It's probably an old response, and we're out of sync.  Just
+		 gobble up the packet and ignore it.  */
+		getpkt (junkbuf, 0);
+		continue;		/* Now, go look for + */
+	      }
+	    default:
+	      if (remote_debug)
+		{
+		  if (!started_error_output)
+		    {
+		      started_error_output = 1;
+		      printf_unfiltered ("putpkt: Junk: ");
+		    }
+		  putchar_unfiltered (ch & 0177);
+		}
+	      continue;
+	    }
+	  break;		/* Here to retransmit */
+	}
+
+#if 0
+      /* This is wrong.  If doing a long backtrace, the user should be
+	 able to get out next time we call QUIT, without anything as violent
+	 as interrupt_query.  If we want to provide a way out of here
+	 without getting to the next QUIT, it should be based on hitting
+	 ^C twice as in remote_wait.  */
+      if (quit_flag)
+	{
+	  quit_flag = 0;
+	  interrupt_query ();
+	}
+#endif
+    }
+}
+
+/* Come here after finding the start of the frame.  Collect the rest into BUF,
+   verifying the checksum, length, and handling run-length compression.
+   Returns 0 on any error, 1 on success.  */
+
+static int
+read_frame (buf)
+     char *buf;
+{
+  unsigned char csum;
+  char *bp;
+  int c;
+
+  csum = 0;
+  bp = buf;
+
+  while (1)
+    {
+      c = readchar (remote_timeout);
+
+      switch (c)
+	{
+	case SERIAL_TIMEOUT:
+	  if (remote_debug)
+	    puts_filtered ("Timeout in mid-packet, retrying\n");
+	  return 0;
+	case '$':
+	  if (remote_debug)
+	    puts_filtered ("Saw new packet start in middle of old one\n");
+	  return 0;		/* Start a new packet, count retries */
+	case '#':
+	  {
+	    unsigned char pktcsum;
+
+	    *bp = '\000';
+
+	    pktcsum = fromhex (readchar (remote_timeout)) << 4;
+	    pktcsum |= fromhex (readchar (remote_timeout));
+
+	    if (csum == pktcsum)
+	      return 1;
+
+	    if (remote_debug) 
+	      {
+		printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=",
+				 pktcsum, csum);
+		puts_filtered (buf);
+		puts_filtered ("\n");
+	      }
+	    return 0;
+	  }
+	case '*':		/* Run length encoding */
+	  csum += c;
+	  c = readchar (remote_timeout);
+	  csum += c;
+	  c = c - ' ' + 3;	/* Compute repeat count */
+
+
+	  if (c > 0 && c < 255 && bp + c - 1 < buf + PBUFSIZ - 1)
+	    {
+	      memset (bp, *(bp - 1), c);
+	      bp += c;
+	      continue;
+	    }
+
+	  *bp = '\0';
+	  printf_filtered ("Repeat count %d too large for buffer: ", c);
+	  puts_filtered (buf);
+	  puts_filtered ("\n");
+	  return 0;
+
+	default:
+	  if (bp < buf + PBUFSIZ - 1)
+	    {
+	      *bp++ = c;
+	      csum += c;
+	      continue;
+	    }
+
+	  *bp = '\0';
+	  puts_filtered ("Remote packet too long: ");
+	  puts_filtered (buf);
+	  puts_filtered ("\n");
+
+	  return 0;
+	}
+    }
+}
+
+/* Read a packet from the remote machine, with error checking,
+   and store it in BUF.  BUF is expected to be of size PBUFSIZ.
+   If FOREVER, wait forever rather than timing out; this is used
+   while the target is executing user code.  */
+
+void
+getpkt (buf, forever)
+     char *buf;
+     int forever;
+{
+  int c;
+  int tries;
+  int timeout;
+  int val;
+
+  strcpy (buf,"timeout");
+
+  if (forever)
+    {
+#ifdef MAINTENANCE_CMDS
+      timeout = watchdog > 0 ? watchdog : -1;
+#else
+      timeout = -1;
+#endif
+    }
+
+  else
+    timeout = remote_timeout;
+
+#define MAX_TRIES 3
+
+  for (tries = 1; tries <= MAX_TRIES; tries++)
+    {
+      /* This can loop forever if the remote side sends us characters
+	 continuously, but if it pauses, we'll get a zero from readchar
+	 because of timeout.  Then we'll count that as a retry.  */
+
+      /* Note that we will only wait forever prior to the start of a packet.
+	 After that, we expect characters to arrive at a brisk pace.  They
+	 should show up within remote_timeout intervals.  */
+
+      do
+	{
+	  c = readchar (timeout);
+
+	  if (c == SERIAL_TIMEOUT)
+	    {
+#ifdef MAINTENANCE_CMDS
+	      if (forever)	/* Watchdog went off.  Kill the target. */
+		{
+		  target_mourn_inferior ();
+		  error ("Watchdog has expired.  Target detached.\n");
+		}
+#endif
+	      if (remote_debug)
+		puts_filtered ("Timed out.\n");
+	      goto retry;
+	    }
+	}
+      while (c != '$');
+
+      /* We've found the start of a packet, now collect the data.  */
+
+      val = read_frame (buf);
+
+      if (val == 1)
+	{
+	  if (remote_debug)
+	    fprintf_unfiltered (gdb_stdout, "Packet received: %s\n", buf);
+	  SERIAL_WRITE (remote_desc, "+", 1);
+	  return;
+	}
+
+      /* Try the whole thing again.  */
+    retry:
+      SERIAL_WRITE (remote_desc, "-", 1);
+    }
+
+  /* We have tried hard enough, and just can't receive the packet.  Give up. */
+
+  printf_unfiltered ("Ignoring packet error, continuing...\n");
+  SERIAL_WRITE (remote_desc, "+", 1);
+}
+
+static void
+remote_kill ()
+{
+  /* For some mysterious reason, wait_for_inferior calls kill instead of
+     mourn after it gets TARGET_WAITKIND_SIGNALLED.  Work around it.  */
+  if (kill_kludge)
+    {
+      kill_kludge = 0;
+      target_mourn_inferior ();
+      return;
+    }
+
+  /* Use catch_errors so the user can quit from gdb even when we aren't on
+     speaking terms with the remote system.  */
+  catch_errors (putpkt, "k", "", RETURN_MASK_ERROR);
+
+  /* Don't wait for it to die.  I'm not really sure it matters whether
+     we do or not.  For the existing stubs, kill is a noop.  */
+  target_mourn_inferior ();
+}
+
+static void
+remote_mourn ()
+{
+  remote_mourn_1 (&remote_ops);
+}
+
+static void
+extended_remote_mourn ()
+{
+  /* We do _not_ want to mourn the target like this; this will
+     remove the extended remote target  from the target stack,
+     and the next time the user says "run" it'll fail. 
+
+     FIXME: What is the right thing to do here?  */
+#if 0
+  remote_mourn_1 (&extended_remote_ops);
+#endif
+}
+
+/* Worker function for remote_mourn.  */
+static void
+remote_mourn_1 (target)
+     struct target_ops *target;
+{
+  unpush_target (target);
+  generic_mourn_inferior ();
+}
+
+/* In the extended protocol we want to be able to do things like
+   "run" and have them basically work as expected.  So we need
+   a special create_inferior function. 
+
+   FIXME: One day add support for changing the exec file
+   we're debugging, arguments and an environment.  */
+
+static void
+extended_remote_create_inferior (exec_file, args, env)
+     char *exec_file;
+     char *args;
+     char **env;
+{
+  /* Rip out the breakpoints; we'll reinsert them after restarting
+     the remote server.  */
+  remove_breakpoints ();
+
+  /* Now restart the remote server.  */
+  extended_remote_restart ();
+
+  /* Now put the breakpoints back in.  This way we're safe if the
+     restart function works via a unix fork on the remote side.  */
+  insert_breakpoints ();
+
+  /* Clean up from the last time we were running.  */
+  clear_proceed_status ();
+
+  /* Let the remote process run.  */
+  proceed (-1, TARGET_SIGNAL_0, 0);
+}
+
+
+/* On some machines, e.g. 68k, we may use a different breakpoint instruction
+   than other targets; in those use REMOTE_BREAKPOINT instead of just
+   BREAKPOINT.  Also, bi-endian targets may define LITTLE_REMOTE_BREAKPOINT
+   and BIG_REMOTE_BREAKPOINT.  If none of these are defined, we just call
+   the standard routines that are in mem-break.c.  */
+
+/* FIXME, these ought to be done in a more dynamic fashion.  For instance,
+   the choice of breakpoint instruction affects target program design and
+   vice versa, and by making it user-tweakable, the special code here
+   goes away and we need fewer special GDB configurations.  */
+
+#if defined (LITTLE_REMOTE_BREAKPOINT) && defined (BIG_REMOTE_BREAKPOINT) && !defined(REMOTE_BREAKPOINT)
+#define REMOTE_BREAKPOINT
+#endif
+
+#ifdef REMOTE_BREAKPOINT
+
+/* If the target isn't bi-endian, just pretend it is.  */
+#if !defined (LITTLE_REMOTE_BREAKPOINT) && !defined (BIG_REMOTE_BREAKPOINT)
+#define LITTLE_REMOTE_BREAKPOINT REMOTE_BREAKPOINT
+#define BIG_REMOTE_BREAKPOINT REMOTE_BREAKPOINT
+#endif
+
+static unsigned char big_break_insn[] = BIG_REMOTE_BREAKPOINT;
+static unsigned char little_break_insn[] = LITTLE_REMOTE_BREAKPOINT;
+
+#endif /* REMOTE_BREAKPOINT */
+
+/* Insert a breakpoint on targets that don't have any better breakpoint
+   support.  We read the contents of the target location and stash it,
+   then overwrite it with a breakpoint instruction.  ADDR is the target
+   location in the target machine.  CONTENTS_CACHE is a pointer to 
+   memory allocated for saving the target contents.  It is guaranteed
+   by the caller to be long enough to save sizeof BREAKPOINT bytes (this
+   is accomplished via BREAKPOINT_MAX).  */
+
+static int
+remote_insert_breakpoint (addr, contents_cache)
+     CORE_ADDR addr;
+     char *contents_cache;
+{
+#ifdef REMOTE_BREAKPOINT
+  int val;
+
+  val = target_read_memory (addr, contents_cache, sizeof big_break_insn);
+
+  if (val == 0)
+    {
+      if (TARGET_BYTE_ORDER == BIG_ENDIAN)
+	val = target_write_memory (addr, (char *) big_break_insn,
+				   sizeof big_break_insn);
+      else
+	val = target_write_memory (addr, (char *) little_break_insn,
+				   sizeof little_break_insn);
+    }
+
+  return val;
+#else
+  return memory_insert_breakpoint (addr, contents_cache);
+#endif /* REMOTE_BREAKPOINT */
+}
+
+static int
+remote_remove_breakpoint (addr, contents_cache)
+     CORE_ADDR addr;
+     char *contents_cache;
+{
+#ifdef REMOTE_BREAKPOINT
+  return target_write_memory (addr, contents_cache, sizeof big_break_insn);
+#else
+  return memory_remove_breakpoint (addr, contents_cache);
+#endif /* REMOTE_BREAKPOINT */
+}
+
+/* Some targets are only capable of doing downloads, and afterwards they switch
+   to the remote serial protocol.  This function provides a clean way to get
+   from the download target to the remote target.  It's basically just a
+   wrapper so that we don't have to expose any of the internal workings of
+   remote.c.
+
+   Prior to calling this routine, you should shutdown the current target code,
+   else you will get the "A program is being debugged already..." message.
+   Usually a call to pop_target() suffices.
+*/
+
+void
+push_remote_target (name, from_tty)
+     char *name;
+     int from_tty;
+{
+  printf_filtered ("Switching to remote protocol\n");
+  remote_open (name, from_tty);
+}
+
+/* Other targets want to use the entire remote serial module but with
+   certain remote_ops overridden. */
+
+void
+open_remote_target (name, from_tty, target, extended_p)
+     char *name;
+     int from_tty;
+     struct target_ops *target;
+     int extended_p;
+{
+  printf_filtered ("Selecting the %sremote protocol\n",
+		   (extended_p ? "extended-" : ""));
+  remote_open_1 (name, from_tty, target, extended_p);
+}
+
+/* Table used by the crc32 function to calcuate the checksum. */
+static unsigned long crc32_table[256] = {0, 0};
+
+static unsigned long
+crc32 (buf, len, crc)
+     unsigned char *buf;
+     int len;
+     unsigned int crc;
+{
+  if (! crc32_table[1])
+    {
+      /* Initialize the CRC table and the decoding table. */
+      int i, j;
+      unsigned int c;
+
+      for (i = 0; i < 256; i++)
+        {
+          for (c = i << 24, j = 8; j > 0; --j)
+            c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1);
+          crc32_table[i] = c;
+        }
+    }
+
+  while (len--)
+    {
+      crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *buf) & 255];
+      buf++;
+    }
+  return crc;
+}
+
+/* compare-sections command
+
+   With no arguments, compares each loadable section in the exec bfd
+   with the same memory range on the target, and reports mismatches.
+   Useful for verifying the image on the target against the exec file.
+   Depends on the target understanding the new "qCRC:" request.  */
+
+static void
+remote_compare_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  asection *s;
+  unsigned long host_crc, target_crc;
+  extern bfd *exec_bfd;
+  struct cleanup *old_chain;
+  char *tmp, *sectdata, *sectname, buf[PBUFSIZ];
+  bfd_size_type size;
+  bfd_vma lma;
+  int matched = 0;
+
+  if (!exec_bfd)
+    error ("command cannot be used without an exec file");
+  if (!current_target.to_shortname ||
+      strcmp (current_target.to_shortname, "remote") != 0)
+    error ("command can only be used with remote target");
+
+  for (s = exec_bfd->sections; s; s = s->next) 
+    {
+      if (!(s->flags & SEC_LOAD))
+	continue;	/* skip non-loadable section */
+
+      size = bfd_get_section_size_before_reloc (s);
+      if (size == 0)
+	continue;	/* skip zero-length section */
+
+      sectname = (char *) bfd_get_section_name (exec_bfd, s);
+      if (args && strcmp (args, sectname) != 0)
+	continue;	/* not the section selected by user */
+
+      matched = 1;	/* do this section */
+      lma = s->lma;
+      /* FIXME: assumes lma can fit into long */
+      sprintf (buf, "qCRC:%lx,%lx", (long) lma, (long) size);
+      putpkt (buf);
+
+      /* be clever; compute the host_crc before waiting for target reply */
+      sectdata = xmalloc (size);
+      old_chain = make_cleanup (free, sectdata);
+      bfd_get_section_contents (exec_bfd, s, sectdata, 0, size);
+      host_crc = crc32 ((unsigned char *) sectdata, size, 0xffffffff);
+
+      getpkt (buf, 0);
+      if (buf[0] == 'E')
+	error ("target memory fault, section %s, range 0x%08x -- 0x%08x",
+	       sectname, lma, lma + size);
+      if (buf[0] != 'C')
+	error ("remote target does not support this operation");
+
+      for (target_crc = 0, tmp = &buf[1]; *tmp; tmp++)
+	target_crc = target_crc * 16 + fromhex (*tmp);
+
+      printf_filtered ("Section %s, range 0x%08x -- 0x%08x: ",
+		       sectname, lma, lma + size);
+      if (host_crc == target_crc)
+	printf_filtered ("matched.\n");
+      else
+	printf_filtered ("MIS-MATCHED!\n");
+
+      do_cleanups (old_chain);
+    }
+  if (args && !matched)
+    printf_filtered ("No loaded section named '%s'.\n", args);
+}
+
+
+void
+_initialize_remote ()
+{
+  init_remote_ops() ;
+  init_extended_remote_ops() ;
+  add_target (&remote_ops);
+  add_target (&extended_remote_ops);
+
+/* Remote target communications for serial-line targets in custom GDB protocol
+   Copyright 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Remote communication protocol.
+
+   A debug packet whose contents are <data>
+   is encapsulated for transmission in the form:
+
+	$ <data> # CSUM1 CSUM2
+
+	<data> must be ASCII alphanumeric and cannot include characters
+	'$' or '#'.  If <data> starts with two characters followed by
+	':', then the existing stubs interpret this as a sequence number.
+
+	CSUM1 and CSUM2 are ascii hex representation of an 8-bit 
+	checksum of <data>, the most significant nibble is sent first.
+	the hex digits 0-9,a-f are used.
+
+   Receiver responds with:
+
+	+	- if CSUM is correct and ready for next packet
+	-	- if CSUM is incorrect
+
+   <data> is as follows:
+   Most values are encoded in ascii hex digits.  Signal numbers are according
+   to the numbering in target.h.
+
+	Request		Packet
+
+	set thread	Hct...		Set thread for subsequent operations.
+					c = 'c' for thread used in step and 
+					continue; t... can be -1 for all
+					threads.
+					c = 'g' for thread used in other
+					operations.  If zero, pick a thread,
+					any thread.
+	reply		OK		for success
+			ENN		for an error.
+
+	read registers  g
+	reply		XX....X		Each byte of register data
+					is described by two hex digits.
+					Registers are in the internal order
+					for GDB, and the bytes in a register
+					are in the same order the machine uses.
+			or ENN		for an error.
+
+	write regs	GXX..XX		Each byte of register data
+					is described by two hex digits.
+	reply		OK		for success
+			ENN		for an error
+
+        write reg	Pn...=r...	Write register n... with value r...,
+					which contains two hex digits for each
+					byte in the register (target byte
+					order).
+	reply		OK		for success
+			ENN		for an error
+	(not supported by all stubs).
+
+	read mem	mAA..AA,LLLL	AA..AA is address, LLLL is length.
+	reply		XX..XX		XX..XX is mem contents
+					Can be fewer bytes than requested
+					if able to read only part of the data.
+			or ENN		NN is errno
+
+	write mem	MAA..AA,LLLL:XX..XX
+					AA..AA is address,
+					LLLL is number of bytes,
+					XX..XX is data
+	reply		OK		for success
+			ENN		for an error (this includes the case
+					where only part of the data was
+					written).
+
+	continue	cAA..AA		AA..AA is address to resume
+					If AA..AA is omitted,
+					resume at same address.
+
+	step		sAA..AA		AA..AA is address to resume
+					If AA..AA is omitted,
+					resume at same address.
+
+	continue with	Csig;AA..AA	Continue with signal sig (hex signal
+	signal				number).  If ;AA..AA is omitted, resume
+					at same address.
+
+	step with	Ssig;AA..AA	Like 'C' but step not continue.
+	signal
+
+	last signal     ?               Reply the current reason for stopping.
+                                        This is the same reply as is generated
+					for step or cont : SAA where AA is the
+					signal number.
+
+	detach          D               Reply OK.
+
+	There is no immediate reply to step or cont.
+	The reply comes when the machine stops.
+	It is		SAA		AA is the signal number.
+
+	or...		TAAn...:r...;n...:r...;n...:r...;
+					AA = signal number
+					n... = register number (hex)
+					  r... = register contents
+					n... = `thread'
+					  r... = thread process ID.  This is
+						 a hex integer.
+					n... = other string not starting 
+					    with valid hex digit.
+					  gdb should ignore this n,r pair
+					  and go on to the next.  This way
+					  we can extend the protocol.
+	or...		WAA		The process exited, and AA is
+					the exit status.  This is only
+					applicable for certains sorts of
+					targets.
+	or...		XAA		The process terminated with signal
+					AA.
+        or...           OXX..XX	XX..XX  is hex encoding of ASCII data. This
+					can happen at any time while the program is
+					running and the debugger should
+					continue to wait for 'W', 'T', etc.
+
+	thread alive	TXX		Find out if the thread XX is alive.
+	reply		OK		thread is still alive
+			ENN		thread is dead
+	
+	remote restart	RXX		Restart the remote server
+
+	extended ops 	!		Use the extended remote protocol.
+					Sticky -- only needs to be set once.
+
+	kill request	k
+
+	toggle debug	d		toggle debug flag (see 386 & 68k stubs)
+	reset		r		reset -- see sparc stub.
+	reserved	<other>		On other requests, the stub should
+					ignore the request and send an empty
+					response ($#<checksum>).  This way
+					we can extend the protocol and GDB
+					can tell whether the stub it is
+					talking to uses the old or the new.
+	search		tAA:PP,MM	Search backwards starting at address
+					AA for a match with pattern PP and
+					mask MM.  PP and MM are 4 bytes.
+					Not supported by all stubs.
+
+	general query	qXXXX		Request info about XXXX.
+	general set	QXXXX=yyyy	Set value of XXXX to yyyy.
+	query sect offs	qOffsets	Get section offsets.  Reply is
+					Text=xxx;Data=yyy;Bss=zzz
+
+	Responses can be run-length encoded to save space.  A '*' means that
+	the next character is an ASCII encoding giving a repeat count which
+	stands for that many repititions of the character preceding the '*'.
+	The encoding is n+29, yielding a printable character where n >=3 
+	(which is where rle starts to win).  Don't use an n > 126.
+
+	So 
+	"0* " means the same as "0000".  */
+
+#include "defs.h"
+#include "gdb_string.h"
+#include <fcntl.h>
+#include "frame.h"
+#include "inferior.h"
+#include "bfd.h"
+#include "symfile.h"
+#include "target.h"
+#include "wait.h"
+/*#include "terminal.h"*/
+#include "gdbcmd.h"
+#include "objfiles.h"
+#include "gdb-stabs.h"
+#include "gdbthread.h"
+
+#include "dcache.h"
+
+#ifdef USG
+#include <sys/types.h>
+#endif
+
+#include <signal.h>
+#include "serial.h"
+
+/* Prototypes for local functions */
+
+static int remote_write_bytes PARAMS ((CORE_ADDR memaddr,
+				       char *myaddr, int len));
+
+static int remote_read_bytes PARAMS ((CORE_ADDR memaddr,
+				      char *myaddr, int len));
+
+static void remote_files_info PARAMS ((struct target_ops *ignore));
+
+static int remote_xfer_memory PARAMS ((CORE_ADDR memaddr, char *myaddr,
+				       int len, int should_write,
+				       struct target_ops *target));
+
+static void remote_prepare_to_store PARAMS ((void));
+
+static void remote_fetch_registers PARAMS ((int regno));
+
+static void remote_resume PARAMS ((int pid, int step,
+				   enum target_signal siggnal));
+
+static int remote_start_remote PARAMS ((char *dummy));
+
+static void remote_open PARAMS ((char *name, int from_tty));
+
+static void extended_remote_open PARAMS ((char *name, int from_tty));
+
+static void remote_open_1 PARAMS ((char *, int, struct target_ops *, int extended_p));
+
+static void remote_close PARAMS ((int quitting));
+
+static void remote_store_registers PARAMS ((int regno));
+
+static void remote_mourn PARAMS ((void));
+
+static void extended_remote_restart PARAMS ((void));
+
+static void extended_remote_mourn PARAMS ((void));
+
+static void extended_remote_create_inferior PARAMS ((char *, char *, char **));
+
+static void remote_mourn_1 PARAMS ((struct target_ops *));
+
+static void remote_send PARAMS ((char *buf));
+
+static int readchar PARAMS ((int timeout));
+
+static int remote_wait PARAMS ((int pid, struct target_waitstatus *status));
+
+static void remote_kill PARAMS ((void));
+
+static int tohex PARAMS ((int nib));
+
+static void remote_detach PARAMS ((char *args, int from_tty));
+
+static void remote_interrupt PARAMS ((int signo));
+
+static void remote_interrupt_twice PARAMS ((int signo));
+
+static void interrupt_query PARAMS ((void));
+
+static void set_thread PARAMS ((int, int));
+
+static int remote_thread_alive PARAMS ((int));
+
+static void get_offsets PARAMS ((void));
+
+static int read_frame PARAMS ((char *));
+
+static int remote_insert_breakpoint PARAMS ((CORE_ADDR, char *));
+
+static int remote_remove_breakpoint PARAMS ((CORE_ADDR, char *));
+
+static int hexnumlen PARAMS ((ULONGEST num));
+
+/* exported functions */
+
+extern int fromhex PARAMS ((int a));
+extern void getpkt PARAMS ((char *buf, int forever));
+extern int putpkt PARAMS ((char *buf));
+
+/* Define the target subroutine names */
+
+static struct target_ops remote_ops ;
+
+static void init_remote_ops(void)
+{
+  remote_ops.to_shortname =   "remote";		
+  remote_ops.to_longname =   "Remote serial target in gdb-specific protocol";
+  remote_ops.to_doc =   "Use a remote computer via a serial line; using a gdb-specific protocol.\n\
+Specify the serial device it is connected to (e.g. /dev/ttya)." ;  
+  remote_ops.to_open =   remote_open;		
+  remote_ops.to_close =   remote_close;		
+  remote_ops.to_attach =   NULL;		
+  remote_ops.to_detach =   remote_detach;	
+  remote_ops.to_resume =   remote_resume;	
+  remote_ops.to_wait  =   remote_wait;		
+  remote_ops.to_fetch_registers  =   remote_fetch_registers;
+  remote_ops.to_store_registers  =   remote_store_registers;
+  remote_ops.to_prepare_to_store =   remote_prepare_to_store;
+  remote_ops.to_xfer_memory  =   remote_xfer_memory;	
+  remote_ops.to_files_info  =   remote_files_info;	
+  remote_ops.to_insert_breakpoint =   remote_insert_breakpoint;
+  remote_ops.to_remove_breakpoint =   remote_remove_breakpoint;
+  remote_ops.to_terminal_init  =   NULL;		
+  remote_ops.to_terminal_inferior =   NULL;		
+  remote_ops.to_terminal_ours_for_output =   NULL;
+  remote_ops.to_terminal_ours  =   NULL;	
+  remote_ops.to_terminal_info  =   NULL;	
+  remote_ops.to_kill  =   remote_kill;		
+  remote_ops.to_load  =   generic_load;		
+  remote_ops.to_lookup_symbol =   NULL;		
+  remote_ops.to_create_inferior =   NULL;	
+  remote_ops.to_mourn_inferior =   remote_mourn;
+  remote_ops.to_can_run  =   0;			
+  remote_ops.to_notice_signals =   0;		
+  remote_ops.to_thread_alive  =   remote_thread_alive;
+  remote_ops.to_stop  =   0;		
+  remote_ops.to_stratum =   process_stratum;
+  remote_ops.DONT_USE =   NULL;		
+  remote_ops.to_has_all_memory =   1;	
+  remote_ops.to_has_memory =   1;	
+  remote_ops.to_has_stack =   1;	
+  remote_ops.to_has_registers =   1;	
+  remote_ops.to_has_execution =   1;	
+  remote_ops.to_sections =   NULL;	
+  remote_ops.to_sections_end =   NULL;	
+  remote_ops.to_magic =   OPS_MAGIC ;	
+} /* init_remote_ops */
+
+static struct target_ops extended_remote_ops ;
+
+static void init_extended_remote_ops(void) 
+{
+  extended_remote_ops.to_shortname =   "extended-remote";	
+  extended_remote_ops.to_longname =   "Extended remote serial target in gdb-specific protocol";
+  extended_remote_ops.to_doc =   "Use a remote computer via a serial line; using a gdb-specific protocol.\n\
+Specify the serial device it is connected to (e.g. /dev/ttya).",
+    extended_remote_ops.to_open =   extended_remote_open;	
+  extended_remote_ops.to_close =   remote_close;	
+  extended_remote_ops.to_attach =   NULL;		
+  extended_remote_ops.to_detach =   remote_detach;	
+  extended_remote_ops.to_resume =   remote_resume;	
+  extended_remote_ops.to_wait  =   remote_wait;		
+  extended_remote_ops.to_fetch_registers  =   remote_fetch_registers;
+  extended_remote_ops.to_store_registers  =   remote_store_registers;	
+  extended_remote_ops.to_prepare_to_store =   remote_prepare_to_store;
+  extended_remote_ops.to_xfer_memory  =   remote_xfer_memory;	
+  extended_remote_ops.to_files_info  =   remote_files_info;	
+  extended_remote_ops.to_insert_breakpoint =   remote_insert_breakpoint;
+  extended_remote_ops.to_remove_breakpoint =   remote_remove_breakpoint;
+  extended_remote_ops.to_terminal_init  =   NULL;		
+  extended_remote_ops.to_terminal_inferior =   NULL;		
+  extended_remote_ops.to_terminal_ours_for_output =   NULL;
+  extended_remote_ops.to_terminal_ours  =   NULL;	
+  extended_remote_ops.to_terminal_info  =   NULL;	
+  extended_remote_ops.to_kill  =   remote_kill;		
+  extended_remote_ops.to_load  =   generic_load;	
+  extended_remote_ops.to_lookup_symbol =   NULL;	
+  extended_remote_ops.to_create_inferior =   extended_remote_create_inferior;
+  extended_remote_ops.to_mourn_inferior =   extended_remote_mourn;
+  extended_remote_ops.to_can_run  =   0;			
+  extended_remote_ops.to_notice_signals =   0;			
+  extended_remote_ops.to_thread_alive  =   remote_thread_alive;
+  extended_remote_ops.to_stop  =   0;			
+  extended_remote_ops.to_stratum =   process_stratum;
+  extended_remote_ops.DONT_USE =   NULL;	
+  extended_remote_ops.to_has_all_memory =   1;	
+  extended_remote_ops.to_has_memory =   1;	
+  extended_remote_ops.to_has_stack =   1;	
+  extended_remote_ops.to_has_registers =   1;	
+  extended_remote_ops.to_has_execution =   1;	
+  extended_remote_ops.to_sections =   NULL;	
+  extended_remote_ops.to_sections_end =   NULL;
+  extended_remote_ops.to_magic =   OPS_MAGIC ;
+} 
+
+
+/* This was 5 seconds, which is a long time to sit and wait.
+   Unless this is going though some terminal server or multiplexer or
+   other form of hairy serial connection, I would think 2 seconds would
+   be plenty.  */
+
+/* Changed to allow option to set timeout value.
+   was static int remote_timeout = 2; */
+extern int remote_timeout;
+
+/* This variable chooses whether to send a ^C or a break when the user
+   requests program interruption.  Although ^C is usually what remote
+   systems expect, and that is the default here, sometimes a break is
+   preferable instead.  */
+
+static int remote_break;
+
+/* Descriptor for I/O to remote machine.  Initialize it to NULL so that
+   remote_open knows that we don't have a file open when the program
+   starts.  */
+static serial_t remote_desc = NULL;
+
+/* Having this larger than 400 causes us to be incompatible with m68k-stub.c
+   and i386-stub.c.  Normally, no one would notice because it only matters
+   for writing large chunks of memory (e.g. in downloads).  Also, this needs
+   to be more than 400 if required to hold the registers (see below, where
+   we round it up based on REGISTER_BYTES).  */
+#define	PBUFSIZ	400
+
+/* Maximum number of bytes to read/write at once.  The value here
+   is chosen to fill up a packet (the headers account for the 32).  */
+#define MAXBUFBYTES ((PBUFSIZ-32)/2)
+
+/* Round up PBUFSIZ to hold all the registers, at least.  */
+/* The blank line after the #if seems to be required to work around a
+   bug in HP's PA compiler.  */
+#if REGISTER_BYTES > MAXBUFBYTES
+
+#undef PBUFSIZ
+#define	PBUFSIZ	(REGISTER_BYTES * 2 + 32)
+#endif
+
+/* This variable sets the number of bytes to be written to the target
+   in a single packet.  Normally PBUFSIZ is satisfactory, but some
+   targets need smaller values (perhaps because the receiving end
+   is slow).  */
+
+static int remote_write_size = PBUFSIZ;
+
+/* This is the size (in chars) of the first response to the `g' command.  This
+   is used to limit the size of the memory read and write commands to prevent
+   stub buffers from overflowing.  The size does not include headers and
+   trailers, it is only the payload size. */
+
+static int remote_register_buf_size = 0;
+
+/* Should we try the 'P' request?  If this is set to one when the stub
+   doesn't support 'P', the only consequence is some unnecessary traffic.  */
+static int stub_supports_P = 1;
+
+/* These are pointers to hook functions that may be set in order to
+   modify resume/wait behavior for a particular architecture.  */
+
+void (*target_resume_hook) PARAMS ((void));
+void (*target_wait_loop_hook) PARAMS ((void));
+
+
+/* These are the threads which we last sent to the remote system.  -1 for all
+   or -2 for not sent yet.  */
+int general_thread;
+int cont_thread;
+
+static void
+set_thread (th, gen)
+     int th;
+     int gen;
+{
+  char buf[PBUFSIZ];
+  int state = gen ? general_thread : cont_thread;
+  if (state == th)
+    return;
+  buf[0] = 'H';
+  buf[1] = gen ? 'g' : 'c';
+  if (th == 42000)
+    {
+      buf[2] = '0';
+      buf[3] = '\0';
+    }
+  else if (th < 0)
+    sprintf (&buf[2], "-%x", -th);
+  else
+    sprintf (&buf[2], "%x", th);
+  putpkt (buf);
+  getpkt (buf, 0);
+  if (gen)
+    general_thread = th;
+  else
+    cont_thread = th;
+}
+
+/*  Return nonzero if the thread TH is still alive on the remote system.  */
+
+static int
+remote_thread_alive (th)
+     int th;
+{
+  char buf[PBUFSIZ];
+
+  buf[0] = 'T';
+  if (th < 0)
+    sprintf (&buf[1], "-%x", -th);
+  else
+    sprintf (&buf[1], "%x", th);
+  putpkt (buf);
+  getpkt (buf, 0);
+  return (buf[0] == 'O' && buf[1] == 'K');
+}
+
+/*  Restart the remote side; this is an extended protocol operation.  */
+
+static void
+extended_remote_restart ()
+{
+  char buf[PBUFSIZ];
+
+  /* Send the restart command; for reasons I don't understand the
+     remote side really expects a number after the "R".  */
+  buf[0] = 'R';
+  sprintf (&buf[1], "%x", 0);
+  putpkt (buf);
+
+  /* Now query for status so this looks just like we restarted
+     gdbserver from scratch.  */
+  putpkt ("?");
+  getpkt (buf, 0);
+}
+
+/* Clean up connection to a remote debugger.  */
+
+/* ARGSUSED */
+static void
+remote_close (quitting)
+     int quitting;
+{
+  if (remote_desc)
+    SERIAL_CLOSE (remote_desc);
+  remote_desc = NULL;
+}
+
+/* Query the remote side for the text, data and bss offsets. */
+
+static void
+get_offsets ()
+{
+  char buf[PBUFSIZ], *ptr;
+  int lose;
+  CORE_ADDR text_addr, data_addr, bss_addr;
+  struct section_offsets *offs;
+
+  putpkt ("qOffsets");
+
+  getpkt (buf, 0);
+
+  if (buf[0] == '\000')
+    return;			/* Return silently.  Stub doesn't support this
+				   command. */
+  if (buf[0] == 'E')
+    {
+      warning ("Remote failure reply: %s", buf);
+      return;
+    }
+
+  /* Pick up each field in turn.  This used to be done with scanf, but
+     scanf will make trouble if CORE_ADDR size doesn't match
+     conversion directives correctly.  The following code will work
+     with any size of CORE_ADDR.  */
+  text_addr = data_addr = bss_addr = 0;
+  ptr = buf;
+  lose = 0;
+
+  if (strncmp (ptr, "Text=", 5) == 0)
+    {
+      ptr += 5;
+      /* Don't use strtol, could lose on big values.  */
+      while (*ptr && *ptr != ';')
+	text_addr = (text_addr << 4) + fromhex (*ptr++);
+    }
+  else
+    lose = 1;
+
+  if (!lose && strncmp (ptr, ";Data=", 6) == 0)
+    {
+      ptr += 6;
+      while (*ptr && *ptr != ';')
+	data_addr = (data_addr << 4) + fromhex (*ptr++);
+    }
+  else
+    lose = 1;
+
+  if (!lose && strncmp (ptr, ";Bss=", 5) == 0)
+    {
+      ptr += 5;
+      while (*ptr && *ptr != ';')
+	bss_addr = (bss_addr << 4) + fromhex (*ptr++);
+    }
+  else
+    lose = 1;
+
+  if (lose)
+    error ("Malformed response to offset query, %s", buf);
+
+  if (symfile_objfile == NULL)
+    return;
+
+  offs = (struct section_offsets *) alloca (sizeof (struct section_offsets)
+					    + symfile_objfile->num_sections
+					    * sizeof (offs->offsets));
+  memcpy (offs, symfile_objfile->section_offsets,
+	  sizeof (struct section_offsets)
+	  + symfile_objfile->num_sections
+	  * sizeof (offs->offsets));
+
+  ANOFFSET (offs, SECT_OFF_TEXT) = text_addr;
+
+  /* This is a temporary kludge to force data and bss to use the same offsets
+     because that's what nlmconv does now.  The real solution requires changes
+     to the stub and remote.c that I don't have time to do right now.  */
+
+  ANOFFSET (offs, SECT_OFF_DATA) = data_addr;
+  ANOFFSET (offs, SECT_OFF_BSS) = data_addr;
+
+  objfile_relocate (symfile_objfile, offs);
+}
+
+/* Stub for catch_errors.  */
+
+static int
+remote_start_remote (dummy)
+     char *dummy;
+{
+  immediate_quit = 1;		/* Allow user to interrupt it */
+
+  /* Ack any packet which the remote side has already sent.  */
+  SERIAL_WRITE (remote_desc, "+", 1);
+
+  /* Let the stub know that we want it to return the thread.  */
+  set_thread (-1, 0);
+
+  get_offsets ();		/* Get text, data & bss offsets */
+
+  putpkt ("?");			/* initiate a query from remote machine */
+  immediate_quit = 0;
+
+  start_remote ();		/* Initialize gdb process mechanisms */
+  return 1;
+}
+
+/* Open a connection to a remote debugger.
+   NAME is the filename used for communication.  */
+
+static void
+remote_open (name, from_tty)
+     char *name;
+     int from_tty;
+{
+  remote_open_1 (name, from_tty, &remote_ops, 0);
+}
+
+/* Open a connection to a remote debugger using the extended
+   remote gdb protocol.  NAME is the filename used for communication.  */
+
+static void
+extended_remote_open (name, from_tty)
+     char *name;
+     int from_tty;
+{
+  remote_open_1 (name, from_tty, &extended_remote_ops, 1/*extended_p*/);
+}
+
+/* Generic code for opening a connection to a remote target.  */
+static DCACHE *remote_dcache;
+
+static void
+remote_open_1 (name, from_tty, target, extended_p)
+     char *name;
+     int from_tty;
+     struct target_ops *target;
+     int extended_p;
+{
+  if (name == 0)
+    error ("To open a remote debug connection, you need to specify what serial\n\
+device is attached to the remote system (e.g. /dev/ttya).");
+
+  target_preopen (from_tty);
+
+  unpush_target (target);
+
+  remote_dcache = dcache_init (remote_read_bytes, remote_write_bytes);
+
+  remote_desc = SERIAL_OPEN (name);
+  if (!remote_desc)
+    perror_with_name (name);
+
+  if (baud_rate != -1)
+    {
+      if (SERIAL_SETBAUDRATE (remote_desc, baud_rate))
+	{
+	  SERIAL_CLOSE (remote_desc);
+	  perror_with_name (name);
+	}
+    }
+
+
+  SERIAL_RAW (remote_desc);
+
+  /* If there is something sitting in the buffer we might take it as a
+     response to a command, which would be bad.  */
+  SERIAL_FLUSH_INPUT (remote_desc);
+
+  if (from_tty)
+    {
+      puts_filtered ("Remote debugging using ");
+      puts_filtered (name);
+      puts_filtered ("\n");
+    }
+  push_target (target);	/* Switch to using remote target now */
+
+  /* Start out by trying the 'P' request to set registers.  We set this each
+     time that we open a new target so that if the user switches from one
+     stub to another, we can (if the target is closed and reopened) cope.  */
+  stub_supports_P = 1;
+
+  general_thread = -2;
+  cont_thread = -2;
+
+  /* Without this, some commands which require an active target (such as kill)
+     won't work.  This variable serves (at least) double duty as both the pid
+     of the target process (if it has such), and as a flag indicating that a
+     target is active.  These functions should be split out into seperate
+     variables, especially since GDB will someday have a notion of debugging
+     several processes.  */
+
+  inferior_pid = 42000;
+  /* Start the remote connection; if error (0), discard this target.
+     In particular, if the user quits, be sure to discard it
+     (we'd be in an inconsistent state otherwise).  */
+  if (!catch_errors (remote_start_remote, (char *)0, 
+		     "Couldn't establish connection to remote target\n", RETURN_MASK_ALL))
+    {
+      pop_target();
+      return;
+    }
 
   if (extended_p)
     {
@@ -2020,6 +6185,217 @@ open_remote_target (name, from_tty, target, extended_p)
   remote_open_1 (name, from_tty, target, extended_p);
 }
 
+/* Table used by the crc32 function to calcuate the checksum. */
+static unsigned long crc32_table[256] = {0, 0};
+
+static unsigned long
+crc32 (buf, len, crc)
+     unsigned char *buf;
+     int len;
+     unsigned int crc;
+{
+  if (! crc32_table[1])
+    {
+      /* Initialize the CRC table and the decoding table. */
+      int i, j;
+      unsigned int c;
+
+      for (i = 0; i < 256; i++)
+        {
+          for (c = i << 24, j = 8; j > 0; --j)
+            c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1);
+          crc32_table[i] = c;
+        }
+    }
+
+  while (len--)
+    {
+      crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *buf) & 255];
+      buf++;
+    }
+  return crc;
+}
+
+/* compare-sections command
+
+   With no arguments, compares each loadable section in the exec bfd
+   with the same memory range on the target, and reports mismatches.
+   Useful for verifying the image on the target against the exec file.
+   Depends on the target understanding the new "qCRC:" request.  */
+
+static void
+remote_compare_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  asection *s;
+  unsigned long host_crc, target_crc;
+  extern bfd *exec_bfd;
+  struct cleanup *old_chain;
+  char *tmp, *sectdata, *sectname, buf[PBUFSIZ];
+  bfd_size_type size;
+  bfd_vma lma;
+  int matched = 0;
+
+  if (!exec_bfd)
+    error ("command cannot be used without an exec file");
+  if (!current_target.to_shortname ||
+      strcmp (current_target.to_shortname, "remote") != 0)
+    error ("command can only be used with remote target");
+
+  for (s = exec_bfd->sections; s; s = s->next) 
+    {
+      if (!(s->flags & SEC_LOAD))
+	continue;	/* skip non-loadable section */
+
+      size = bfd_get_section_size_before_reloc (s);
+      if (size == 0)
+	continue;	/* skip zero-length section */
+
+      sectname = (char *) bfd_get_section_name (exec_bfd, s);
+      if (args && strcmp (args, sectname) != 0)
+	continue;	/* not the section selected by user */
+
+      matched = 1;	/* do this section */
+      lma = s->lma;
+      /* FIXME: assumes lma can fit into long */
+      sprintf (buf, "qCRC:%lx,%lx", (long) lma, (long) size);
+      putpkt (buf);
+
+      /* be clever; compute the host_crc before waiting for target reply */
+      sectdata = xmalloc (size);
+      old_chain = make_cleanup (free, sectdata);
+      bfd_get_section_contents (exec_bfd, s, sectdata, 0, size);
+      host_crc = crc32 ((unsigned char *) sectdata, size, 0xffffffff);
+
+      getpkt (buf, 0);
+      if (buf[0] == 'E')
+	error ("target memory fault, section %s, range 0x%08x -- 0x%08x",
+	       sectname, lma, lma + size);
+      if (buf[0] != 'C')
+	error ("remote target does not support this operation");
+
+      for (target_crc = 0, tmp = &buf[1]; *tmp; tmp++)
+	target_crc = target_crc * 16 + fromhex (*tmp);
+
+      printf_filtered ("Section %s, range 0x%08x -- 0x%08x: ",
+		       sectname, lma, lma + size);
+      if (host_crc == target_crc)
+	printf_filtered ("matched.\n");
+      else
+	printf_filtered ("MIS-MATCHED!\n");
+
+      do_cleanups (old_chain);
+    }
+  if (args && !matched)
+    printf_filtered ("No loaded section named '%s'.\n", args);
+}
+
+/* reload command
+
+   With no arguments, compares each loadable section on the target 
+   with the binary image in the current exec bfd.  Sections that 
+   are not identical are downloaded to the target.  Depends on the
+   target understanding the "qCRC:" request.
+
+   Optionally accepts the name of a section as an argument, and
+   downloads that section; in this case no comparison is done --
+   the section is downloaded unconditionally.  */
+
+static void
+remote_reload_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  asection *s;
+  unsigned long host_crc, target_crc;
+  extern bfd *exec_bfd;
+  struct cleanup *old_chain;
+  char *tmp, *sectdata, *sectname, buf[PBUFSIZ];
+  bfd_size_type size;
+  bfd_vma lma;
+  unsigned long sent, len, l;
+  int matched = 0;
+  int err;
+
+  if (!exec_bfd)
+    error ("command cannot be used without an exec file");
+
+  for (s = exec_bfd->sections; s; s = s->next) 
+    {
+      if (!(s->flags & SEC_LOAD))
+	continue;	/* skip non-loadable section */
+
+      size = bfd_get_section_size_before_reloc (s);
+      if (size == 0)
+	continue;	/* skip zero-length section */
+
+      sectname = (char *) bfd_get_section_name (exec_bfd, s);
+      if (args && strcmp (args, sectname) != 0)
+	continue;	/* not the section selected by user */
+
+      matched = 1;	/* do this section */
+      lma = s->lma;
+      sectdata = xmalloc (size);
+      old_chain = make_cleanup (free, sectdata);
+      bfd_get_section_contents (exec_bfd, s, sectdata, 0, size);
+
+      if (args == 0)
+	{
+	  /*
+	   * Compare all sections, and reload those that don't match.
+	   */
+
+	  if (!current_target.to_shortname ||
+	      strcmp (current_target.to_shortname, "remote") != 0)
+	    error ("command can only be used with remote target");
+
+	  /* FIXME: assumes lma can fit into long */
+	  sprintf (buf, "qCRC:%lx,%lx", (long) lma, (long) size);
+	  putpkt (buf);
+
+	  /* be clever; compute the host_crc before waiting for target reply */
+	  host_crc = crc32 ((unsigned char *) sectdata, size, 0xffffffff);
+
+	  getpkt (buf, 0);
+	  if (buf[0] == 'E')
+	    error ("target memory fault, section %s, range 0x%08x -- 0x%08x",
+		   sectname, lma, lma + size);
+	  if (buf[0] != 'C')
+	    error ("remote target does not support this operation");
+
+	  for (target_crc = 0, tmp = &buf[1]; *tmp; tmp++)
+	    target_crc = target_crc * 16 + fromhex (*tmp);
+	}
+
+      printf_filtered ("Section %s, range 0x%08x -- 0x%08x: ",
+		       sectname, lma, lma + size);
+
+      if (args != 0 ||	/* section specified -- reload unconditionally */
+	  host_crc != target_crc)	/* section changed on target   */
+	{
+	  printf_filtered ("being reloaded now.\n");
+	  l = size / 100;
+	  l = l > 100 ? l : 100;	/* chunk size; at least 100 */
+	  sent = 0;
+	  do 
+	    {
+	      len = (size - sent) < l ? (size - sent) : l;
+	      sent += len;
+	      err = target_write_memory (lma, sectdata, len);
+	      lma += len;
+	      sectdata += len;
+	    }
+	  while (err == 0 && sent < size);
+	}
+      else
+	printf_filtered ("unchanged.\n");
+
+      do_cleanups (old_chain);
+    }
+  if (args && !matched)
+    printf_filtered ("No loaded section named '%s'.\n", args);
+}
 
 void
 _initialize_remote ()
@@ -2029,6 +6405,11 @@ _initialize_remote ()
   add_target (&remote_ops);
   add_target (&extended_remote_ops);
 
+  add_cmd ("compare-sections", class_obscure, remote_compare_command, 
+	   "Compare section data on remote target to the exec file.\n\
+Optional argument is a single section name (default: all loadable sections).", 
+	   &cmdlist);
+
   add_show_from_set (add_set_cmd ("remotetimeout", no_class,
 				  var_integer, (char *)&remote_timeout,
 				  "Set timeout value for remote read.\n", &setlist),