gdb/gdbserver/server.c - binutils-gdb - Git at Google

 /* Main code for remote server for GDB.
    Copyright 1989, 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2002, 2003, 2004,
    2005
    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.  */

 #include "server.h"

 #include <unistd.h>
 #include <signal.h>
 #include <sys/wait.h>

 unsigned long cont_thread;
 unsigned long general_thread;
 unsigned long step_thread;
 unsigned long thread_from_wait;
 unsigned long old_thread_from_wait;
 int extended_protocol;
 int server_waiting;

 jmp_buf toplevel;

 /* The PID of the originally created or attached inferior.  Used to
    send signals to the process when GDB sends us an asynchronous interrupt
    (user hitting Control-C in the client), and to wait for the child to exit
    when no longer debugging it.  */

 unsigned long signal_pid;

 static unsigned char
 start_inferior (char *argv[], char *statusptr)
 {
   signal (SIGTTOU, SIG_DFL);
   signal (SIGTTIN, SIG_DFL);

   signal_pid = create_inferior (argv[0], argv);

   fprintf (stderr, "Process %s created; pid = %ld\n", argv[0],
 	   signal_pid);

   signal (SIGTTOU, SIG_IGN);
   signal (SIGTTIN, SIG_IGN);
   tcsetpgrp (fileno (stderr), signal_pid);

   /* Wait till we are at 1st instruction in program, return signal number.  */
   return mywait (statusptr, 0);
 }

 static int
 attach_inferior (int pid, char *statusptr, unsigned char *sigptr)
 {
   /* myattach should return -1 if attaching is unsupported,
      0 if it succeeded, and call error() otherwise.  */

   if (myattach (pid) != 0)
     return -1;

   fprintf (stderr, "Attached; pid = %d\n", pid);

   /* FIXME - It may be that we should get the SIGNAL_PID from the
      attach function, so that it can be the main thread instead of
      whichever we were told to attach to.  */
   signal_pid = pid;

   *sigptr = mywait (statusptr, 0);

   return 0;
 }

 extern int remote_debug;

 /* Handle all of the extended 'q' packets.  */
 void
 handle_query (char *own_buf)
 {
   static struct inferior_list_entry *thread_ptr;

   if (strcmp ("qSymbol::", own_buf) == 0)
     {
       if (the_target->look_up_symbols != NULL)
 	(*the_target->look_up_symbols) ();

       strcpy (own_buf, "OK");
       return;
     }

   if (strcmp ("qfThreadInfo", own_buf) == 0)
     {
       thread_ptr = all_threads.head;
       sprintf (own_buf, "m%lx", thread_ptr->id);
       thread_ptr = thread_ptr->next;
       return;
     }

   if (strcmp ("qsThreadInfo", own_buf) == 0)
     {
       if (thread_ptr != NULL)
 	{
 	  sprintf (own_buf, "m%lx", thread_ptr->id);
 	  thread_ptr = thread_ptr->next;
 	  return;
 	}
       else
 	{
 	  sprintf (own_buf, "l");
 	  return;
 	}
     }

   if (the_target->read_auxv != NULL
       && strncmp ("qPart:auxv:read::", own_buf, 17) == 0)
     {
       char data[(PBUFSIZ - 1) / 2];
       CORE_ADDR ofs;
       unsigned int len;
       int n;
       decode_m_packet (&own_buf[17], &ofs, &len); /* "OFS,LEN" */
       if (len > sizeof data)
 	len = sizeof data;
       n = (*the_target->read_auxv) (ofs, data, len);
       if (n == 0)
 	write_ok (own_buf);
       else if (n < 0)
 	write_enn (own_buf);
       else
 	convert_int_to_ascii (data, own_buf, n);
       return;
     }

   /* Otherwise we didn't know what packet it was.  Say we didn't
      understand it.  */
   own_buf[0] = 0;
 }

 /* Parse vCont packets.  */
 void
 handle_v_cont (char *own_buf, char *status, unsigned char *signal)
 {
   char *p, *q;
   int n = 0, i = 0;
   struct thread_resume *resume_info, default_action;

   /* Count the number of semicolons in the packet.  There should be one
      for every action.  */
   p = &own_buf[5];
   while (p)
     {
       n++;
       p++;
       p = strchr (p, ';');
     }
   /* Allocate room for one extra action, for the default remain-stopped
      behavior; if no default action is in the list, we'll need the extra
      slot.  */
   resume_info = malloc ((n + 1) * sizeof (resume_info[0]));

   default_action.thread = -1;
   default_action.leave_stopped = 1;
   default_action.step = 0;
   default_action.sig = 0;

   p = &own_buf[5];
   i = 0;
   while (*p)
     {
       p++;

       resume_info[i].leave_stopped = 0;

       if (p[0] == 's' || p[0] == 'S')
 	resume_info[i].step = 1;
       else if (p[0] == 'c' || p[0] == 'C')
 	resume_info[i].step = 0;
       else
 	goto err;

       if (p[0] == 'S' || p[0] == 'C')
 	{
 	  int sig;
 	  sig = strtol (p + 1, &q, 16);
 	  if (p == q)
 	    goto err;
 	  p = q;

 	  if (!target_signal_to_host_p (sig))
 	    goto err;
 	  resume_info[i].sig = target_signal_to_host (sig);
 	}
       else
 	{
 	  resume_info[i].sig = 0;
 	  p = p + 1;
 	}

       if (p[0] == 0)
 	{
 	  resume_info[i].thread = -1;
 	  default_action = resume_info[i];

 	  /* Note: we don't increment i here, we'll overwrite this entry
 	     the next time through.  */
 	}
       else if (p[0] == ':')
 	{
 	  resume_info[i].thread = strtoul (p + 1, &q, 16);
 	  if (p == q)
 	    goto err;
 	  p = q;
 	  if (p[0] != ';' && p[0] != 0)
 	    goto err;

 	  i++;
 	}
     }

   resume_info[i] = default_action;

   /* Still used in occasional places in the backend.  */
   if (n == 1 && resume_info[0].thread != -1)
     cont_thread = resume_info[0].thread;
   else
     cont_thread = -1;
   set_desired_inferior (0);

   (*the_target->resume) (resume_info);

   free (resume_info);

   *signal = mywait (status, 1);
   prepare_resume_reply (own_buf, *status, *signal);
   return;

 err:
   /* No other way to report an error... */
   strcpy (own_buf, "");
   free (resume_info);
   return;
 }

 /* Handle all of the extended 'v' packets.  */
 void
 handle_v_requests (char *own_buf, char *status, unsigned char *signal)
 {
   if (strncmp (own_buf, "vCont;", 6) == 0)
     {
       handle_v_cont (own_buf, status, signal);
       return;
     }

   if (strncmp (own_buf, "vCont?", 6) == 0)
     {
       strcpy (own_buf, "vCont;c;C;s;S");
       return;
     }

   /* Otherwise we didn't know what packet it was.  Say we didn't
      understand it.  */
   own_buf[0] = 0;
   return;
 }

 void
 myresume (int step, int sig)
 {
   struct thread_resume resume_info[2];
   int n = 0;

   if (step || sig || cont_thread > 0)
     {
       resume_info[0].thread
 	= ((struct inferior_list_entry *) current_inferior)->id;
       resume_info[0].step = step;
       resume_info[0].sig = sig;
       resume_info[0].leave_stopped = 0;
       n++;
     }
   resume_info[n].thread = -1;
   resume_info[n].step = 0;
   resume_info[n].sig = 0;
   resume_info[n].leave_stopped = (cont_thread > 0);

   (*the_target->resume) (resume_info);
 }

 static int attached;

 static void
 gdbserver_usage (void)
 {
   error ("Usage:\tgdbserver COMM PROG [ARGS ...]\n"
 	 "\tgdbserver COMM --attach PID\n"
 	 "\n"
 	 "COMM may either be a tty device (for serial debugging), or \n"
 	 "HOST:PORT to listen for a TCP connection.\n");
 }

 int
 main (int argc, char *argv[])
 {
   char ch, status, *own_buf, mem_buf[2000];
   int i = 0;
   unsigned char signal;
   unsigned int len;
   CORE_ADDR mem_addr;
   int bad_attach;
   int pid;
   char *arg_end;

   if (setjmp (toplevel))
     {
       fprintf (stderr, "Exiting\n");
       exit (1);
     }

   bad_attach = 0;
   pid = 0;
   attached = 0;
   if (argc >= 3 && strcmp (argv[2], "--attach") == 0)
     {
       if (argc == 4
 	  && argv[3] != '\0'
 	  && (pid = strtoul (argv[3], &arg_end, 10)) != 0
 	  && *arg_end == '\0')
 	{
 	  ;
 	}
       else
 	bad_attach = 1;
     }

   if (argc < 3 || bad_attach)
     gdbserver_usage();

   initialize_low ();

   own_buf = malloc (PBUFSIZ);

   if (pid == 0)
     {
       /* Wait till we are at first instruction in program.  */
       signal = start_inferior (&argv[2], &status);

       /* We are now stopped at the first instruction of the target process */
     }
   else
     {
       switch (attach_inferior (pid, &status, &signal))
 	{
 	case -1:
 	  error ("Attaching not supported on this target");
 	  break;
 	default:
 	  attached = 1;
 	  break;
 	}
     }

   while (1)
     {
       remote_open (argv[1]);

     restart:
       setjmp (toplevel);
       while (getpkt (own_buf) > 0)
 	{
 	  unsigned char sig;
 	  i = 0;
 	  ch = own_buf[i++];
 	  switch (ch)
 	    {
 	    case 'q':
 	      handle_query (own_buf);
 	      break;
 	    case 'd':
 	      remote_debug = !remote_debug;
 	      break;
 	    case 'D':
 	      fprintf (stderr, "Detaching from inferior\n");
 	      detach_inferior ();
 	      write_ok (own_buf);
 	      putpkt (own_buf);
 	      remote_close ();

 	      /* If we are attached, then we can exit.  Otherwise, we need to
 		 hang around doing nothing, until the child is gone.  */
 	      if (!attached)
 		{
 		  int status, ret;

 		  do {
 		    ret = waitpid (signal_pid, &status, 0);
 		    if (WIFEXITED (status) || WIFSIGNALED (status))
 		      break;
 		  } while (ret != -1 || errno != ECHILD);
 		}

 	      exit (0);

 	    case '!':
 	      if (attached == 0)
 		{
 		  extended_protocol = 1;
 		  prepare_resume_reply (own_buf, status, signal);
 		}
 	      else
 		{
 		  /* We can not use the extended protocol if we are
 		     attached, because we can not restart the running
 		     program.  So return unrecognized.  */
 		  own_buf[0] = '\0';
 		}
 	      break;
 	    case '?':
 	      prepare_resume_reply (own_buf, status, signal);
 	      break;
 	    case 'H':
 	      switch (own_buf[1])
 		{
 		case 'g':
 		  general_thread = strtoul (&own_buf[2], NULL, 16);
 		  write_ok (own_buf);
 		  set_desired_inferior (1);
 		  break;
 		case 'c':
 		  cont_thread = strtoul (&own_buf[2], NULL, 16);
 		  write_ok (own_buf);
 		  break;
 		case 's':
 		  step_thread = strtoul (&own_buf[2], NULL, 16);
 		  write_ok (own_buf);
 		  break;
 		default:
 		  /* Silently ignore it so that gdb can extend the protocol
 		     without compatibility headaches.  */
 		  own_buf[0] = '\0';
 		  break;
 		}
 	      break;
 	    case 'g':
 	      set_desired_inferior (1);
 	      registers_to_string (own_buf);
 	      break;
 	    case 'G':
 	      set_desired_inferior (1);
 	      registers_from_string (&own_buf[1]);
 	      write_ok (own_buf);
 	      break;
 	    case 'm':
 	      decode_m_packet (&own_buf[1], &mem_addr, &len);
 	      if (read_inferior_memory (mem_addr, mem_buf, len) == 0)
 		convert_int_to_ascii (mem_buf, own_buf, len);
 	      else
 		write_enn (own_buf);
 	      break;
 	    case 'M':
 	      decode_M_packet (&own_buf[1], &mem_addr, &len, mem_buf);
 	      if (write_inferior_memory (mem_addr, mem_buf, len) == 0)
 		write_ok (own_buf);
 	      else
 		write_enn (own_buf);
 	      break;
 	    case 'C':
 	      convert_ascii_to_int (own_buf + 1, &sig, 1);
 	      if (target_signal_to_host_p (sig))
 		signal = target_signal_to_host (sig);
 	      else
 		signal = 0;
 	      set_desired_inferior (0);
 	      myresume (0, signal);
 	      signal = mywait (&status, 1);
 	      prepare_resume_reply (own_buf, status, signal);
 	      break;
 	    case 'S':
 	      convert_ascii_to_int (own_buf + 1, &sig, 1);
 	      if (target_signal_to_host_p (sig))
 		signal = target_signal_to_host (sig);
 	      else
 		signal = 0;
 	      set_desired_inferior (0);
 	      myresume (1, signal);
 	      signal = mywait (&status, 1);
 	      prepare_resume_reply (own_buf, status, signal);
 	      break;
 	    case 'c':
 	      set_desired_inferior (0);
 	      myresume (0, 0);
 	      signal = mywait (&status, 1);
 	      prepare_resume_reply (own_buf, status, signal);
 	      break;
 	    case 's':
 	      set_desired_inferior (0);
 	      myresume (1, 0);
 	      signal = mywait (&status, 1);
 	      prepare_resume_reply (own_buf, status, signal);
 	      break;
 	    case 'k':
 	      fprintf (stderr, "Killing inferior\n");
 	      kill_inferior ();
 	      /* When using the extended protocol, we start up a new
 	         debugging session.   The traditional protocol will
 	         exit instead.  */
 	      if (extended_protocol)
 		{
 		  write_ok (own_buf);
 		  fprintf (stderr, "GDBserver restarting\n");

 		  /* Wait till we are at 1st instruction in prog.  */
 		  signal = start_inferior (&argv[2], &status);
 		  goto restart;
 		  break;
 		}
 	      else
 		{
 		  exit (0);
 		  break;
 		}
 	    case 'T':
 	      if (mythread_alive (strtoul (&own_buf[1], NULL, 16)))
 		write_ok (own_buf);
 	      else
 		write_enn (own_buf);
 	      break;
 	    case 'R':
 	      /* Restarting the inferior is only supported in the
 	         extended protocol.  */
 	      if (extended_protocol)
 		{
 		  kill_inferior ();
 		  write_ok (own_buf);
 		  fprintf (stderr, "GDBserver restarting\n");

 		  /* Wait till we are at 1st instruction in prog.  */
 		  signal = start_inferior (&argv[2], &status);
 		  goto restart;
 		  break;
 		}
 	      else
 		{
 		  /* It is a request we don't understand.  Respond with an
 		     empty packet so that gdb knows that we don't support this
 		     request.  */
 		  own_buf[0] = '\0';
 		  break;
 		}
 	    case 'v':
 	      /* Extended (long) request.  */
 	      handle_v_requests (own_buf, &status, &signal);
 	      break;
 	    default:
 	      /* It is a request we don't understand.  Respond with an
 	         empty packet so that gdb knows that we don't support this
 	         request.  */
 	      own_buf[0] = '\0';
 	      break;
 	    }

 	  putpkt (own_buf);

 	  if (status == 'W')
 	    fprintf (stderr,
 		     "\nChild exited with status %d\n", signal);
 	  if (status == 'X')
 	    fprintf (stderr, "\nChild terminated with signal = 0x%x\n",
 		     signal);
 	  if (status == 'W' || status == 'X')
 	    {
 	      if (extended_protocol)
 		{
 		  fprintf (stderr, "Killing inferior\n");
 		  kill_inferior ();
 		  write_ok (own_buf);
 		  fprintf (stderr, "GDBserver restarting\n");

 		  /* Wait till we are at 1st instruction in prog.  */
 		  signal = start_inferior (&argv[2], &status);
 		  goto restart;
 		  break;
 		}
 	      else
 		{
 		  fprintf (stderr, "GDBserver exiting\n");
 		  exit (0);
 		}
 	    }
 	}

       /* We come here when getpkt fails.

          For the extended remote protocol we exit (and this is the only
          way we gracefully exit!).

          For the traditional remote protocol close the connection,
          and re-open it at the top of the loop.  */
       if (extended_protocol)
 	{
 	  remote_close ();
 	  exit (0);
 	}
       else
 	{
 	  fprintf (stderr, "Remote side has terminated connection.  "
 			   "GDBserver will reopen the connection.\n");
 	  remote_close ();
 	}
     }
 }
	/* Main code for remote server for GDB.
	Copyright 1989, 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2002, 2003, 2004,
	2005
	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. */

	#include "server.h"

	#include <unistd.h>
	#include <signal.h>
	#include <sys/wait.h>

	unsigned long cont_thread;
	unsigned long general_thread;
	unsigned long step_thread;
	unsigned long thread_from_wait;
	unsigned long old_thread_from_wait;
	int extended_protocol;
	int server_waiting;

	jmp_buf toplevel;

	/* The PID of the originally created or attached inferior. Used to
	send signals to the process when GDB sends us an asynchronous interrupt
	(user hitting Control-C in the client), and to wait for the child to exit
	when no longer debugging it. */

	unsigned long signal_pid;

	static unsigned char
	start_inferior (char argv[], char statusptr)
	{
	signal (SIGTTOU, SIG_DFL);
	signal (SIGTTIN, SIG_DFL);

	signal_pid = create_inferior (argv[0], argv);

	fprintf (stderr, "Process %s created; pid = %ld\n", argv[0],
	signal_pid);

	signal (SIGTTOU, SIG_IGN);
	signal (SIGTTIN, SIG_IGN);
	tcsetpgrp (fileno (stderr), signal_pid);

	/* Wait till we are at 1st instruction in program, return signal number. */
	return mywait (statusptr, 0);
	}

	static int
	attach_inferior (int pid, char statusptr, unsigned char sigptr)
	{
	/* myattach should return -1 if attaching is unsupported,
	0 if it succeeded, and call error() otherwise. */

	if (myattach (pid) != 0)
	return -1;

	fprintf (stderr, "Attached; pid = %d\n", pid);

	/* FIXME - It may be that we should get the SIGNAL_PID from the
	attach function, so that it can be the main thread instead of
	whichever we were told to attach to. */
	signal_pid = pid;

	*sigptr = mywait (statusptr, 0);

	return 0;
	}

	extern int remote_debug;

	/* Handle all of the extended 'q' packets. */
	void
	handle_query (char *own_buf)
	{
	static struct inferior_list_entry *thread_ptr;

	if (strcmp ("qSymbol::", own_buf) == 0)
	{
	if (the_target->look_up_symbols != NULL)
	(*the_target->look_up_symbols) ();

	strcpy (own_buf, "OK");
	return;
	}

	if (strcmp ("qfThreadInfo", own_buf) == 0)
	{
	thread_ptr = all_threads.head;
	sprintf (own_buf, "m%lx", thread_ptr->id);
	thread_ptr = thread_ptr->next;
	return;
	}

	if (strcmp ("qsThreadInfo", own_buf) == 0)
	{
	if (thread_ptr != NULL)
	{
	sprintf (own_buf, "m%lx", thread_ptr->id);
	thread_ptr = thread_ptr->next;
	return;
	}
	else
	{
	sprintf (own_buf, "l");
	return;
	}
	}

	if (the_target->read_auxv != NULL
	&& strncmp ("qPart:auxv:read::", own_buf, 17) == 0)
	{
	char data[(PBUFSIZ - 1) / 2];
	CORE_ADDR ofs;
	unsigned int len;
	int n;
	decode_m_packet (&own_buf[17], &ofs, &len); /* "OFS,LEN" */
	if (len > sizeof data)
	len = sizeof data;
	n = (*the_target->read_auxv) (ofs, data, len);
	if (n == 0)
	write_ok (own_buf);
	else if (n < 0)
	write_enn (own_buf);
	else
	convert_int_to_ascii (data, own_buf, n);
	return;
	}

	/* Otherwise we didn't know what packet it was. Say we didn't
	understand it. */
	own_buf[0] = 0;
	}

	/* Parse vCont packets. */
	void
	handle_v_cont (char own_buf, char status, unsigned char *signal)
	{
	char p, q;
	int n = 0, i = 0;
	struct thread_resume *resume_info, default_action;

	/* Count the number of semicolons in the packet. There should be one
	for every action. */
	p = &own_buf[5];
	while (p)
	{
	n++;
	p++;
	p = strchr (p, ';');
	}
	/* Allocate room for one extra action, for the default remain-stopped
	behavior; if no default action is in the list, we'll need the extra
	slot. */
	resume_info = malloc ((n + 1) * sizeof (resume_info[0]));

	default_action.thread = -1;
	default_action.leave_stopped = 1;
	default_action.step = 0;
	default_action.sig = 0;

	p = &own_buf[5];
	i = 0;
	while (*p)
	{
	p++;

	resume_info[i].leave_stopped = 0;

	if (p[0] == 's' \|\| p[0] == 'S')
	resume_info[i].step = 1;
	else if (p[0] == 'c' \|\| p[0] == 'C')
	resume_info[i].step = 0;
	else
	goto err;

	if (p[0] == 'S' \|\| p[0] == 'C')
	{
	int sig;
	sig = strtol (p + 1, &q, 16);
	if (p == q)
	goto err;
	p = q;

	if (!target_signal_to_host_p (sig))
	goto err;
	resume_info[i].sig = target_signal_to_host (sig);
	}
	else
	{
	resume_info[i].sig = 0;
	p = p + 1;
	}

	if (p[0] == 0)
	{
	resume_info[i].thread = -1;
	default_action = resume_info[i];

	/* Note: we don't increment i here, we'll overwrite this entry
	the next time through. */
	}
	else if (p[0] == ':')
	{
	resume_info[i].thread = strtoul (p + 1, &q, 16);
	if (p == q)
	goto err;
	p = q;
	if (p[0] != ';' && p[0] != 0)
	goto err;

	i++;
	}
	}

	resume_info[i] = default_action;

	/* Still used in occasional places in the backend. */
	if (n == 1 && resume_info[0].thread != -1)
	cont_thread = resume_info[0].thread;
	else
	cont_thread = -1;
	set_desired_inferior (0);

	(*the_target->resume) (resume_info);

	free (resume_info);

	*signal = mywait (status, 1);
	prepare_resume_reply (own_buf, status, signal);
	return;

	err:
	/* No other way to report an error... */
	strcpy (own_buf, "");
	free (resume_info);
	return;
	}

	/* Handle all of the extended 'v' packets. */
	void
	handle_v_requests (char own_buf, char status, unsigned char *signal)
	{
	if (strncmp (own_buf, "vCont;", 6) == 0)
	{
	handle_v_cont (own_buf, status, signal);
	return;
	}

	if (strncmp (own_buf, "vCont?", 6) == 0)
	{
	strcpy (own_buf, "vCont;c;C;s;S");
	return;
	}

	/* Otherwise we didn't know what packet it was. Say we didn't
	understand it. */
	own_buf[0] = 0;
	return;
	}

	void
	myresume (int step, int sig)
	{
	struct thread_resume resume_info[2];
	int n = 0;

	if (step \|\| sig \|\| cont_thread > 0)
	{
	resume_info[0].thread
	= ((struct inferior_list_entry *) current_inferior)->id;
	resume_info[0].step = step;
	resume_info[0].sig = sig;
	resume_info[0].leave_stopped = 0;
	n++;
	}
	resume_info[n].thread = -1;
	resume_info[n].step = 0;
	resume_info[n].sig = 0;
	resume_info[n].leave_stopped = (cont_thread > 0);

	(*the_target->resume) (resume_info);
	}

	static int attached;

	static void
	gdbserver_usage (void)
	{
	error ("Usage:\tgdbserver COMM PROG [ARGS ...]\n"
	"\tgdbserver COMM --attach PID\n"
	"\n"
	"COMM may either be a tty device (for serial debugging), or \n"
	"HOST:PORT to listen for a TCP connection.\n");
	}

	int
	main (int argc, char *argv[])
	{
	char ch, status, *own_buf, mem_buf[2000];
	int i = 0;
	unsigned char signal;
	unsigned int len;
	CORE_ADDR mem_addr;
	int bad_attach;
	int pid;
	char *arg_end;

	if (setjmp (toplevel))
	{
	fprintf (stderr, "Exiting\n");
	exit (1);
	}

	bad_attach = 0;
	pid = 0;
	attached = 0;
	if (argc >= 3 && strcmp (argv[2], "--attach") == 0)
	{
	if (argc == 4
	&& argv[3] != '\0'
	&& (pid = strtoul (argv[3], &arg_end, 10)) != 0
	&& *arg_end == '\0')
	{
	;
	}
	else
	bad_attach = 1;
	}

	if (argc < 3 \|\| bad_attach)
	gdbserver_usage();

	initialize_low ();

	own_buf = malloc (PBUFSIZ);

	if (pid == 0)
	{
	/* Wait till we are at first instruction in program. */
	signal = start_inferior (&argv[2], &status);

	/* We are now stopped at the first instruction of the target process */
	}
	else
	{
	switch (attach_inferior (pid, &status, &signal))
	{
	case -1:
	error ("Attaching not supported on this target");
	break;
	default:
	attached = 1;
	break;
	}
	}

	while (1)
	{
	remote_open (argv[1]);

	restart:
	setjmp (toplevel);
	while (getpkt (own_buf) > 0)
	{
	unsigned char sig;
	i = 0;
	ch = own_buf[i++];
	switch (ch)
	{
	case 'q':
	handle_query (own_buf);
	break;
	case 'd':
	remote_debug = !remote_debug;
	break;
	case 'D':
	fprintf (stderr, "Detaching from inferior\n");
	detach_inferior ();
	write_ok (own_buf);
	putpkt (own_buf);
	remote_close ();

	/* If we are attached, then we can exit. Otherwise, we need to
	hang around doing nothing, until the child is gone. */
	if (!attached)
	{
	int status, ret;

	do {
	ret = waitpid (signal_pid, &status, 0);
	if (WIFEXITED (status) \|\| WIFSIGNALED (status))
	break;
	} while (ret != -1 \|\| errno != ECHILD);
	}

	exit (0);

	case '!':
	if (attached == 0)
	{
	extended_protocol = 1;
	prepare_resume_reply (own_buf, status, signal);
	}
	else
	{
	/* We can not use the extended protocol if we are
	attached, because we can not restart the running
	program. So return unrecognized. */
	own_buf[0] = '\0';
	}
	break;
	case '?':
	prepare_resume_reply (own_buf, status, signal);
	break;
	case 'H':
	switch (own_buf[1])
	{
	case 'g':
	general_thread = strtoul (&own_buf[2], NULL, 16);
	write_ok (own_buf);
	set_desired_inferior (1);
	break;
	case 'c':
	cont_thread = strtoul (&own_buf[2], NULL, 16);
	write_ok (own_buf);
	break;
	case 's':
	step_thread = strtoul (&own_buf[2], NULL, 16);
	write_ok (own_buf);
	break;
	default:
	/* Silently ignore it so that gdb can extend the protocol
	without compatibility headaches. */
	own_buf[0] = '\0';
	break;
	}
	break;
	case 'g':
	set_desired_inferior (1);
	registers_to_string (own_buf);
	break;
	case 'G':
	set_desired_inferior (1);
	registers_from_string (&own_buf[1]);
	write_ok (own_buf);
	break;
	case 'm':
	decode_m_packet (&own_buf[1], &mem_addr, &len);
	if (read_inferior_memory (mem_addr, mem_buf, len) == 0)
	convert_int_to_ascii (mem_buf, own_buf, len);
	else
	write_enn (own_buf);
	break;
	case 'M':
	decode_M_packet (&own_buf[1], &mem_addr, &len, mem_buf);
	if (write_inferior_memory (mem_addr, mem_buf, len) == 0)
	write_ok (own_buf);
	else
	write_enn (own_buf);
	break;
	case 'C':
	convert_ascii_to_int (own_buf + 1, &sig, 1);
	if (target_signal_to_host_p (sig))
	signal = target_signal_to_host (sig);
	else
	signal = 0;
	set_desired_inferior (0);
	myresume (0, signal);
	signal = mywait (&status, 1);
	prepare_resume_reply (own_buf, status, signal);
	break;
	case 'S':
	convert_ascii_to_int (own_buf + 1, &sig, 1);
	if (target_signal_to_host_p (sig))
	signal = target_signal_to_host (sig);
	else
	signal = 0;
	set_desired_inferior (0);
	myresume (1, signal);
	signal = mywait (&status, 1);
	prepare_resume_reply (own_buf, status, signal);
	break;
	case 'c':
	set_desired_inferior (0);
	myresume (0, 0);
	signal = mywait (&status, 1);
	prepare_resume_reply (own_buf, status, signal);
	break;
	case 's':
	set_desired_inferior (0);
	myresume (1, 0);
	signal = mywait (&status, 1);
	prepare_resume_reply (own_buf, status, signal);
	break;
	case 'k':
	fprintf (stderr, "Killing inferior\n");
	kill_inferior ();
	/* When using the extended protocol, we start up a new
	debugging session. The traditional protocol will
	exit instead. */
	if (extended_protocol)
	{
	write_ok (own_buf);
	fprintf (stderr, "GDBserver restarting\n");

	/* Wait till we are at 1st instruction in prog. */
	signal = start_inferior (&argv[2], &status);
	goto restart;
	break;
	}
	else
	{
	exit (0);
	break;
	}
	case 'T':
	if (mythread_alive (strtoul (&own_buf[1], NULL, 16)))
	write_ok (own_buf);
	else
	write_enn (own_buf);
	break;
	case 'R':
	/* Restarting the inferior is only supported in the
	extended protocol. */
	if (extended_protocol)
	{
	kill_inferior ();
	write_ok (own_buf);
	fprintf (stderr, "GDBserver restarting\n");

	/* Wait till we are at 1st instruction in prog. */
	signal = start_inferior (&argv[2], &status);
	goto restart;
	break;
	}
	else
	{
	/* It is a request we don't understand. Respond with an
	empty packet so that gdb knows that we don't support this
	request. */
	own_buf[0] = '\0';
	break;
	}
	case 'v':
	/* Extended (long) request. */
	handle_v_requests (own_buf, &status, &signal);
	break;
	default:
	/* It is a request we don't understand. Respond with an
	empty packet so that gdb knows that we don't support this
	request. */
	own_buf[0] = '\0';
	break;
	}

	putpkt (own_buf);

	if (status == 'W')
	fprintf (stderr,
	"\nChild exited with status %d\n", signal);
	if (status == 'X')
	fprintf (stderr, "\nChild terminated with signal = 0x%x\n",
	signal);
	if (status == 'W' \|\| status == 'X')
	{
	if (extended_protocol)
	{
	fprintf (stderr, "Killing inferior\n");
	kill_inferior ();
	write_ok (own_buf);
	fprintf (stderr, "GDBserver restarting\n");

	/* Wait till we are at 1st instruction in prog. */
	signal = start_inferior (&argv[2], &status);
	goto restart;
	break;
	}
	else
	{
	fprintf (stderr, "GDBserver exiting\n");
	exit (0);
	}
	}
	}

	/* We come here when getpkt fails.

	For the extended remote protocol we exit (and this is the only
	way we gracefully exit!).

	For the traditional remote protocol close the connection,
	and re-open it at the top of the loop. */
	if (extended_protocol)
	{
	remote_close ();
	exit (0);
	}
	else
	{
	fprintf (stderr, "Remote side has terminated connection. "
	"GDBserver will reopen the connection.\n");
	remote_close ();
	}
	}
	}