/* Machine independent support for QNX Neutrino /proc (process file system)
   for GDB.  Written by Colin Burgess at QNX Software Systems Limited. 

   Copyright (C) 2003, 2006 Free Software Foundation, Inc.

   Contributed by QNX Software Systems Ltd.

   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., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#include "defs.h"

#include <fcntl.h>
#include <spawn.h>
#include <sys/debug.h>
#include <sys/procfs.h>
#include <sys/neutrino.h>
#include <sys/syspage.h>
#include "gdb_dirent.h"
#include <sys/netmgr.h>

#include "exceptions.h"
#include "gdb_string.h"
#include "gdbcore.h"
#include "inferior.h"
#include "target.h"
#include "objfiles.h"
#include "gdbthread.h"
#include "nto-tdep.h"
#include "command.h"
#include "regcache.h"

#define NULL_PID		0
#define _DEBUG_FLAG_TRACE	(_DEBUG_FLAG_TRACE_EXEC|_DEBUG_FLAG_TRACE_RD|\
		_DEBUG_FLAG_TRACE_WR|_DEBUG_FLAG_TRACE_MODIFY)

static struct target_ops procfs_ops;

int ctl_fd;

static void (*ofunc) ();

static procfs_run run;

static void procfs_open (char *, int);

static int procfs_can_run (void);

static ptid_t procfs_wait (ptid_t, struct target_waitstatus *);

static int procfs_xfer_memory (CORE_ADDR, char *, int, int,
			       struct mem_attrib *attrib,
			       struct target_ops *);

static void procfs_fetch_registers (int);

static void notice_signals (void);

static void init_procfs_ops (void);

static ptid_t do_attach (ptid_t ptid);

static int procfs_can_use_hw_breakpoint (int, int, int);

static int procfs_insert_hw_watchpoint (CORE_ADDR addr, int len, int type);

static int procfs_remove_hw_watchpoint (CORE_ADDR addr, int len, int type);

static int procfs_stopped_by_watchpoint (void);

/* These two globals are only ever set in procfs_open(), but are
   referenced elsewhere.  'nto_procfs_node' is a flag used to say
   whether we are local, or we should get the current node descriptor
   for the remote QNX node.  */
static char nto_procfs_path[PATH_MAX] = { "/proc" };
static unsigned nto_procfs_node = ND_LOCAL_NODE;

/* Return the current QNX Node, or error out.  This is a simple
   wrapper for the netmgr_strtond() function.  The reason this
   is required is because QNX node descriptors are transient so
   we have to re-acquire them every time.  */
static unsigned
nto_node (void)
{
  unsigned node;

  if (ND_NODE_CMP (nto_procfs_node, ND_LOCAL_NODE) == 0)
    return ND_LOCAL_NODE;

  node = netmgr_strtond (nto_procfs_path, 0);
  if (node == -1)
    error (_("Lost the QNX node.  Debug session probably over."));

  return (node);
}

static enum gdb_osabi
procfs_is_nto_target (bfd *abfd)
{
  return GDB_OSABI_QNXNTO;
}

/* This is called when we call 'target procfs <arg>' from the (gdb) prompt.
   For QNX6 (nto), the only valid arg will be a QNX node string, 
   eg: "/net/some_node".  If arg is not a valid QNX node, we will
   default to local.  */
static void
procfs_open (char *arg, int from_tty)
{
  char *nodestr;
  char *endstr;
  char buffer[50];
  int fd, total_size;
  procfs_sysinfo *sysinfo;

  nto_is_nto_target = procfs_is_nto_target;

  /* Set the default node used for spawning to this one,
     and only override it if there is a valid arg.  */

  nto_procfs_node = ND_LOCAL_NODE;
  nodestr = arg ? xstrdup (arg) : arg;

  init_thread_list ();

  if (nodestr)
    {
      nto_procfs_node = netmgr_strtond (nodestr, &endstr);
      if (nto_procfs_node == -1)
	{
	  if (errno == ENOTSUP)
	    printf_filtered ("QNX Net Manager not found.\n");
	  printf_filtered ("Invalid QNX node %s: error %d (%s).\n", nodestr,
			   errno, safe_strerror (errno));
	  xfree (nodestr);
	  nodestr = NULL;
	  nto_procfs_node = ND_LOCAL_NODE;
	}
      else if (*endstr)
	{
	  if (*(endstr - 1) == '/')
	    *(endstr - 1) = 0;
	  else
	    *endstr = 0;
	}
    }
  snprintf (nto_procfs_path, PATH_MAX - 1, "%s%s", nodestr ? nodestr : "",
	    "/proc");
  if (nodestr)
    xfree (nodestr);

  fd = open (nto_procfs_path, O_RDONLY);
  if (fd == -1)
    {
      printf_filtered ("Error opening %s : %d (%s)\n", nto_procfs_path, errno,
		       safe_strerror (errno));
      error (_("Invalid procfs arg"));
    }

  sysinfo = (void *) buffer;
  if (devctl (fd, DCMD_PROC_SYSINFO, sysinfo, sizeof buffer, 0) != EOK)
    {
      printf_filtered ("Error getting size: %d (%s)\n", errno,
		       safe_strerror (errno));
      close (fd);
      error (_("Devctl failed."));
    }
  else
    {
      total_size = sysinfo->total_size;
      sysinfo = alloca (total_size);
      if (!sysinfo)
	{
	  printf_filtered ("Memory error: %d (%s)\n", errno,
			   safe_strerror (errno));
	  close (fd);
	  error (_("alloca failed."));
	}
      else
	{
	  if (devctl (fd, DCMD_PROC_SYSINFO, sysinfo, total_size, 0) != EOK)
	    {
	      printf_filtered ("Error getting sysinfo: %d (%s)\n", errno,
			       safe_strerror (errno));
	      close (fd);
	      error (_("Devctl failed."));
	    }
	  else
	    {
	      if (sysinfo->type !=
		  nto_map_arch_to_cputype (TARGET_ARCHITECTURE->arch_name))
		{
		  close (fd);
		  error (_("Invalid target CPU."));
		}
	    }
	}
    }
  close (fd);
  printf_filtered ("Debugging using %s\n", nto_procfs_path);
}

static void
procfs_set_thread (ptid_t ptid)
{
  pid_t tid;

  tid = ptid_get_tid (ptid);
  devctl (ctl_fd, DCMD_PROC_CURTHREAD, &tid, sizeof (tid), 0);
}

/*  Return nonzero if the thread TH is still alive.  */
static int
procfs_thread_alive (ptid_t ptid)
{
  pid_t tid;

  tid = ptid_get_tid (ptid);
  if (devctl (ctl_fd, DCMD_PROC_CURTHREAD, &tid, sizeof (tid), 0) == EOK)
    return 1;
  return 0;
}

void
procfs_find_new_threads (void)
{
  procfs_status status;
  pid_t pid;
  ptid_t ptid;

  if (ctl_fd == -1)
    return;

  pid = ptid_get_pid (inferior_ptid);

  for (status.tid = 1;; ++status.tid)
    {
      if (devctl (ctl_fd, DCMD_PROC_TIDSTATUS, &status, sizeof (status), 0)
	  != EOK && status.tid != 0)
	break;
      ptid = ptid_build (pid, 0, status.tid);
      if (!in_thread_list (ptid))
	add_thread (ptid);
    }
  return;
}

void
procfs_pidlist (char *args, int from_tty)
{
  DIR *dp = NULL;
  struct dirent *dirp = NULL;
  int fd = -1;
  char buf[512];
  procfs_info *pidinfo = NULL;
  procfs_debuginfo *info = NULL;
  procfs_status *status = NULL;
  pid_t num_threads = 0;
  pid_t pid;
  char name[512];

  dp = opendir (nto_procfs_path);
  if (dp == NULL)
    {
      fprintf_unfiltered (gdb_stderr, "failed to opendir \"%s\" - %d (%s)",
			  nto_procfs_path, errno, safe_strerror (errno));
      return;
    }

  /* Start scan at first pid.  */
  rewinddir (dp);

  do
    {
      /* Get the right pid and procfs path for the pid.  */
      do
	{
	  dirp = readdir (dp);
	  if (dirp == NULL)
	    {
	      closedir (dp);
	      return;
	    }
	  snprintf (buf, 511, "%s/%s/as", nto_procfs_path, dirp->d_name);
	  pid = atoi (dirp->d_name);
	}
      while (pid == 0);

      /* Open the procfs path. */
      fd = open (buf, O_RDONLY);
      if (fd == -1)
	{
	  fprintf_unfiltered (gdb_stderr, "failed to open %s - %d (%s)\n",
			      buf, errno, safe_strerror (errno));
	  closedir (dp);
	  return;
	}

      pidinfo = (procfs_info *) buf;
      if (devctl (fd, DCMD_PROC_INFO, pidinfo, sizeof (buf), 0) != EOK)
	{
	  fprintf_unfiltered (gdb_stderr,
			      "devctl DCMD_PROC_INFO failed - %d (%s)\n",
			      errno, safe_strerror (errno));
	  break;
	}
      num_threads = pidinfo->num_threads;

      info = (procfs_debuginfo *) buf;
      if (devctl (fd, DCMD_PROC_MAPDEBUG_BASE, info, sizeof (buf), 0) != EOK)
	strcpy (name, "unavailable");
      else
	strcpy (name, info->path);

      /* Collect state info on all the threads.  */
      status = (procfs_status *) buf;
      for (status->tid = 1; status->tid <= num_threads; status->tid++)
	{
	  if (devctl (fd, DCMD_PROC_TIDSTATUS, status, sizeof (buf), 0) != EOK
	      && status->tid != 0)
	    break;
	  if (status->tid != 0)
	    printf_filtered ("%s - %d/%d\n", name, pid, status->tid);
	}
      close (fd);
    }
  while (dirp != NULL);

  close (fd);
  closedir (dp);
  return;
}

void
procfs_meminfo (char *args, int from_tty)
{
  procfs_mapinfo *mapinfos = NULL;
  static int num_mapinfos = 0;
  procfs_mapinfo *mapinfo_p, *mapinfo_p2;
  int flags = ~0, err, num, i, j;

  struct
  {
    procfs_debuginfo info;
    char buff[_POSIX_PATH_MAX];
  } map;

  struct info
  {
    unsigned addr;
    unsigned size;
    unsigned flags;
    unsigned debug_vaddr;
    unsigned long long offset;
  };

  struct printinfo
  {
    unsigned long long ino;
    unsigned dev;
    struct info text;
    struct info data;
    char name[256];
  } printme;

  /* Get the number of map entrys.  */
  err = devctl (ctl_fd, DCMD_PROC_MAPINFO, NULL, 0, &num);
  if (err != EOK)
    {
      printf ("failed devctl num mapinfos - %d (%s)\n", err,
	      safe_strerror (err));
      return;
    }

  mapinfos = xmalloc (num * sizeof (procfs_mapinfo));

  num_mapinfos = num;
  mapinfo_p = mapinfos;

  /* Fill the map entrys.  */
  err = devctl (ctl_fd, DCMD_PROC_MAPINFO, mapinfo_p, num
		* sizeof (procfs_mapinfo), &num);
  if (err != EOK)
    {
      printf ("failed devctl mapinfos - %d (%s)\n", err, safe_strerror (err));
      xfree (mapinfos);
      return;
    }

  num = min (num, num_mapinfos);

  /* Run through the list of mapinfos, and store the data and text info
     so we can print it at the bottom of the loop.  */
  for (mapinfo_p = mapinfos, i = 0; i < num; i++, mapinfo_p++)
    {
      if (!(mapinfo_p->flags & flags))
	mapinfo_p->ino = 0;

      if (mapinfo_p->ino == 0)	/* Already visited.  */
	continue;

      map.info.vaddr = mapinfo_p->vaddr;

      err = devctl (ctl_fd, DCMD_PROC_MAPDEBUG, &map, sizeof (map), 0);
      if (err != EOK)
	continue;

      memset (&printme, 0, sizeof printme);
      printme.dev = mapinfo_p->dev;
      printme.ino = mapinfo_p->ino;
      printme.text.addr = mapinfo_p->vaddr;
      printme.text.size = mapinfo_p->size;
      printme.text.flags = mapinfo_p->flags;
      printme.text.offset = mapinfo_p->offset;
      printme.text.debug_vaddr = map.info.vaddr;
      strcpy (printme.name, map.info.path);

      /* Check for matching data.  */
      for (mapinfo_p2 = mapinfos, j = 0; j < num; j++, mapinfo_p2++)
	{
	  if (mapinfo_p2->vaddr != mapinfo_p->vaddr
	      && mapinfo_p2->ino == mapinfo_p->ino
	      && mapinfo_p2->dev == mapinfo_p->dev)
	    {
	      map.info.vaddr = mapinfo_p2->vaddr;
	      err =
		devctl (ctl_fd, DCMD_PROC_MAPDEBUG, &map, sizeof (map), 0);
	      if (err != EOK)
		continue;

	      if (strcmp (map.info.path, printme.name))
		continue;

	      /* Lower debug_vaddr is always text, if nessessary, swap.  */
	      if ((int) map.info.vaddr < (int) printme.text.debug_vaddr)
		{
		  memcpy (&(printme.data), &(printme.text),
			  sizeof (printme.data));
		  printme.text.addr = mapinfo_p2->vaddr;
		  printme.text.size = mapinfo_p2->size;
		  printme.text.flags = mapinfo_p2->flags;
		  printme.text.offset = mapinfo_p2->offset;
		  printme.text.debug_vaddr = map.info.vaddr;
		}
	      else
		{
		  printme.data.addr = mapinfo_p2->vaddr;
		  printme.data.size = mapinfo_p2->size;
		  printme.data.flags = mapinfo_p2->flags;
		  printme.data.offset = mapinfo_p2->offset;
		  printme.data.debug_vaddr = map.info.vaddr;
		}
	      mapinfo_p2->ino = 0;
	    }
	}
      mapinfo_p->ino = 0;

      printf_filtered ("%s\n", printme.name);
      printf_filtered ("\ttext=%08x bytes @ 0x%08x\n", printme.text.size,
		       printme.text.addr);
      printf_filtered ("\t\tflags=%08x\n", printme.text.flags);
      printf_filtered ("\t\tdebug=%08x\n", printme.text.debug_vaddr);
      printf_filtered ("\t\toffset=%016llx\n", printme.text.offset);
      if (printme.data.size)
	{
	  printf_filtered ("\tdata=%08x bytes @ 0x%08x\n", printme.data.size,
			   printme.data.addr);
	  printf_filtered ("\t\tflags=%08x\n", printme.data.flags);
	  printf_filtered ("\t\tdebug=%08x\n", printme.data.debug_vaddr);
	  printf_filtered ("\t\toffset=%016llx\n", printme.data.offset);
	}
      printf_filtered ("\tdev=0x%x\n", printme.dev);
      printf_filtered ("\tino=0x%x\n", (unsigned int) printme.ino);
    }
  xfree (mapinfos);
  return;
}

/* Print status information about what we're accessing.  */
static void
procfs_files_info (struct target_ops *ignore)
{
  printf_unfiltered ("\tUsing the running image of %s %s via %s.\n",
		     attach_flag ? "attached" : "child",
		     target_pid_to_str (inferior_ptid), nto_procfs_path);
}

/* Mark our target-struct as eligible for stray "run" and "attach" commands.  */
static int
procfs_can_run (void)
{
  return 1;
}

/* Attach to process PID, then initialize for debugging it.  */
static void
procfs_attach (char *args, int from_tty)
{
  char *exec_file;
  int pid;

  if (!args)
    error_no_arg (_("process-id to attach"));

  pid = atoi (args);

  if (pid == getpid ())
    error (_("Attaching GDB to itself is not a good idea..."));

  if (from_tty)
    {
      exec_file = (char *) get_exec_file (0);

      if (exec_file)
	printf_unfiltered ("Attaching to program `%s', %s\n", exec_file,
			   target_pid_to_str (pid_to_ptid (pid)));
      else
	printf_unfiltered ("Attaching to %s\n",
			   target_pid_to_str (pid_to_ptid (pid)));

      gdb_flush (gdb_stdout);
    }
  inferior_ptid = do_attach (pid_to_ptid (pid));
  push_target (&procfs_ops);
}

static void
procfs_post_attach (pid_t pid)
{
  if (exec_bfd)
    solib_create_inferior_hook ();
}

static ptid_t
do_attach (ptid_t ptid)
{
  procfs_status status;
  struct sigevent event;
  char path[PATH_MAX];

  snprintf (path, PATH_MAX - 1, "%s/%d/as", nto_procfs_path, PIDGET (ptid));
  ctl_fd = open (path, O_RDWR);
  if (ctl_fd == -1)
    error (_("Couldn't open proc file %s, error %d (%s)"), path, errno,
	   safe_strerror (errno));
  if (devctl (ctl_fd, DCMD_PROC_STOP, &status, sizeof (status), 0) != EOK)
    error (_("Couldn't stop process"));

  /* Define a sigevent for process stopped notification.  */
  event.sigev_notify = SIGEV_SIGNAL_THREAD;
  event.sigev_signo = SIGUSR1;
  event.sigev_code = 0;
  event.sigev_value.sival_ptr = NULL;
  event.sigev_priority = -1;
  devctl (ctl_fd, DCMD_PROC_EVENT, &event, sizeof (event), 0);

  if (devctl (ctl_fd, DCMD_PROC_STATUS, &status, sizeof (status), 0) == EOK
      && status.flags & _DEBUG_FLAG_STOPPED)
    SignalKill (nto_node (), PIDGET (ptid), 0, SIGCONT, 0, 0);
  attach_flag = 1;
  nto_init_solib_absolute_prefix ();
  return ptid;
}

/* Ask the user what to do when an interrupt is received.  */
static void
interrupt_query (void)
{
  target_terminal_ours ();

  if (query ("Interrupted while waiting for the program.\n\
Give up (and stop debugging it)? "))
    {
      target_mourn_inferior ();
      deprecated_throw_reason (RETURN_QUIT);
    }

  target_terminal_inferior ();
}

/* The user typed ^C twice.  */
static void
nto_interrupt_twice (int signo)
{
  signal (signo, ofunc);
  interrupt_query ();
  signal (signo, nto_interrupt_twice);
}

static void
nto_interrupt (int signo)
{
  /* If this doesn't work, try more severe steps.  */
  signal (signo, nto_interrupt_twice);

  target_stop ();
}

static ptid_t
procfs_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
{
  sigset_t set;
  siginfo_t info;
  procfs_status status;
  static int exit_signo = 0;	/* To track signals that cause termination.  */

  ourstatus->kind = TARGET_WAITKIND_SPURIOUS;

  if (ptid_equal (inferior_ptid, null_ptid))
    {
      ourstatus->kind = TARGET_WAITKIND_STOPPED;
      ourstatus->value.sig = TARGET_SIGNAL_0;
      exit_signo = 0;
      return null_ptid;
    }

  sigemptyset (&set);
  sigaddset (&set, SIGUSR1);

  devctl (ctl_fd, DCMD_PROC_STATUS, &status, sizeof (status), 0);
  while (!(status.flags & _DEBUG_FLAG_ISTOP))
    {
      ofunc = (void (*)()) signal (SIGINT, nto_interrupt);
      sigwaitinfo (&set, &info);
      signal (SIGINT, ofunc);
      devctl (ctl_fd, DCMD_PROC_STATUS, &status, sizeof (status), 0);
    }

  if (status.flags & _DEBUG_FLAG_SSTEP)
    {
      ourstatus->kind = TARGET_WAITKIND_STOPPED;
      ourstatus->value.sig = TARGET_SIGNAL_TRAP;
    }
  /* Was it a breakpoint?  */
  else if (status.flags & _DEBUG_FLAG_TRACE)
    {
      ourstatus->kind = TARGET_WAITKIND_STOPPED;
      ourstatus->value.sig = TARGET_SIGNAL_TRAP;
    }
  else if (status.flags & _DEBUG_FLAG_ISTOP)
    {
      switch (status.why)
	{
	case _DEBUG_WHY_SIGNALLED:
	  ourstatus->kind = TARGET_WAITKIND_STOPPED;
	  ourstatus->value.sig =
	    target_signal_from_host (status.info.si_signo);
	  exit_signo = 0;
	  break;
	case _DEBUG_WHY_FAULTED:
	  ourstatus->kind = TARGET_WAITKIND_STOPPED;
	  if (status.info.si_signo == SIGTRAP)
	    {
	      ourstatus->value.sig = 0;
	      exit_signo = 0;
	    }
	  else
	    {
	      ourstatus->value.sig =
		target_signal_from_host (status.info.si_signo);
	      exit_signo = ourstatus->value.sig;
	    }
	  break;

	case _DEBUG_WHY_TERMINATED:
	  {
	    int waitval = 0;

	    waitpid (PIDGET (inferior_ptid), &waitval, WNOHANG);
	    if (exit_signo)
	      {
		/* Abnormal death.  */
		ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
		ourstatus->value.sig = exit_signo;
	      }
	    else
	      {
		/* Normal death.  */
		ourstatus->kind = TARGET_WAITKIND_EXITED;
		ourstatus->value.integer = WEXITSTATUS (waitval);
	      }
	    exit_signo = 0;
	    break;
	  }

	case _DEBUG_WHY_REQUESTED:
	  /* We are assuming a requested stop is due to a SIGINT.  */
	  ourstatus->kind = TARGET_WAITKIND_STOPPED;
	  ourstatus->value.sig = TARGET_SIGNAL_INT;
	  exit_signo = 0;
	  break;
	}
    }

  return inferior_ptid;
}

/* Read the current values of the inferior's registers, both the
   general register set and floating point registers (if supported)
   and update gdb's idea of their current values.  */
static void
procfs_fetch_registers (int regno)
{
  union
  {
    procfs_greg greg;
    procfs_fpreg fpreg;
    procfs_altreg altreg;
  }
  reg;
  int regsize;

  procfs_set_thread (inferior_ptid);
  if (devctl (ctl_fd, DCMD_PROC_GETGREG, &reg, sizeof (reg), &regsize) == EOK)
    nto_supply_gregset ((char *) &reg.greg);
  if (devctl (ctl_fd, DCMD_PROC_GETFPREG, &reg, sizeof (reg), &regsize)
      == EOK)
    nto_supply_fpregset ((char *) &reg.fpreg);
  if (devctl (ctl_fd, DCMD_PROC_GETALTREG, &reg, sizeof (reg), &regsize)
      == EOK)
    nto_supply_altregset ((char *) &reg.altreg);
}

/* Copy LEN bytes to/from inferior's memory starting at MEMADDR
   from/to debugger memory starting at MYADDR.  Copy from inferior
   if DOWRITE is zero or to inferior if DOWRITE is nonzero.

   Returns the length copied, which is either the LEN argument or
   zero.  This xfer function does not do partial moves, since procfs_ops
   doesn't allow memory operations to cross below us in the target stack
   anyway.  */
static int
procfs_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int dowrite,
		    struct mem_attrib *attrib, struct target_ops *target)
{
  int nbytes = 0;

  if (lseek (ctl_fd, (off_t) memaddr, SEEK_SET) == (off_t) memaddr)
    {
      if (dowrite)
	nbytes = write (ctl_fd, myaddr, len);
      else
	nbytes = read (ctl_fd, myaddr, len);
      if (nbytes < 0)
	nbytes = 0;
    }
  return (nbytes);
}

/* Take a program previously attached to and detaches it.
   The program resumes execution and will no longer stop
   on signals, etc.  We'd better not have left any breakpoints
   in the program or it'll die when it hits one.  */
static void
procfs_detach (char *args, int from_tty)
{
  int siggnal = 0;

  if (from_tty)
    {
      char *exec_file = get_exec_file (0);
      if (exec_file == 0)
	exec_file = "";
      printf_unfiltered ("Detaching from program: %s %s\n",
			 exec_file, target_pid_to_str (inferior_ptid));
      gdb_flush (gdb_stdout);
    }
  if (args)
    siggnal = atoi (args);

  if (siggnal)
    SignalKill (nto_node (), PIDGET (inferior_ptid), 0, siggnal, 0, 0);

  close (ctl_fd);
  ctl_fd = -1;
  init_thread_list ();
  inferior_ptid = null_ptid;
  attach_flag = 0;
  unpush_target (&procfs_ops);	/* Pop out of handling an inferior.  */
}

static int
procfs_breakpoint (CORE_ADDR addr, int type, int size)
{
  procfs_break brk;

  brk.type = type;
  brk.addr = addr;
  brk.size = size;
  errno = devctl (ctl_fd, DCMD_PROC_BREAK, &brk, sizeof (brk), 0);
  if (errno != EOK)
    return 1;
  return 0;
}

static int
procfs_insert_breakpoint (struct bp_target_info *bp_tgt)
{
  return procfs_breakpoint (bp_tgt->placed_address, _DEBUG_BREAK_EXEC, 0);
}

static int
procfs_remove_breakpoint (struct bp_target_info *bp_tgt)
{
  return procfs_breakpoint (bp_tgt->placed_address, _DEBUG_BREAK_EXEC, -1);
}

static int
procfs_insert_hw_breakpoint (struct bp_target_info *bp_tgt)
{
  return procfs_breakpoint (bp_tgt->placed_address,
			    _DEBUG_BREAK_EXEC | _DEBUG_BREAK_HW, 0);
}

static int
procfs_remove_hw_breakpoint (struct bp_target_info *bp_tgt)
{
  return procfs_breakpoint (bp_tgt->placed_address,
			    _DEBUG_BREAK_EXEC | _DEBUG_BREAK_HW, -1);
}

static void
procfs_resume (ptid_t ptid, int step, enum target_signal signo)
{
  int signal_to_pass;
  procfs_status status;

  if (ptid_equal (inferior_ptid, null_ptid))
    return;

  procfs_set_thread (ptid_equal (ptid, minus_one_ptid) ? inferior_ptid :
		     ptid);

  run.flags = _DEBUG_RUN_FAULT | _DEBUG_RUN_TRACE;
  if (step)
    run.flags |= _DEBUG_RUN_STEP;

  sigemptyset ((sigset_t *) &run.fault);
  sigaddset ((sigset_t *) &run.fault, FLTBPT);
  sigaddset ((sigset_t *) &run.fault, FLTTRACE);
  sigaddset ((sigset_t *) &run.fault, FLTILL);
  sigaddset ((sigset_t *) &run.fault, FLTPRIV);
  sigaddset ((sigset_t *) &run.fault, FLTBOUNDS);
  sigaddset ((sigset_t *) &run.fault, FLTIOVF);
  sigaddset ((sigset_t *) &run.fault, FLTIZDIV);
  sigaddset ((sigset_t *) &run.fault, FLTFPE);
  /* Peter V will be changing this at some point.  */
  sigaddset ((sigset_t *) &run.fault, FLTPAGE);

  run.flags |= _DEBUG_RUN_ARM;

  sigemptyset (&run.trace);
  notice_signals ();
  signal_to_pass = target_signal_to_host (signo);

  if (signal_to_pass)
    {
      devctl (ctl_fd, DCMD_PROC_STATUS, &status, sizeof (status), 0);
      signal_to_pass = target_signal_to_host (signo);
      if (status.why & (_DEBUG_WHY_SIGNALLED | _DEBUG_WHY_FAULTED))
	{
	  if (signal_to_pass != status.info.si_signo)
	    {
	      SignalKill (nto_node (), PIDGET (inferior_ptid), 0,
			  signal_to_pass, 0, 0);
	      run.flags |= _DEBUG_RUN_CLRFLT | _DEBUG_RUN_CLRSIG;
	    }
	  else			/* Let it kill the program without telling us.  */
	    sigdelset (&run.trace, signal_to_pass);
	}
    }
  else
    run.flags |= _DEBUG_RUN_CLRSIG | _DEBUG_RUN_CLRFLT;

  errno = devctl (ctl_fd, DCMD_PROC_RUN, &run, sizeof (run), 0);
  if (errno != EOK)
    {
      perror ("run error!\n");
      return;
    }
}

static void
procfs_mourn_inferior (void)
{
  if (!ptid_equal (inferior_ptid, null_ptid))
    {
      SignalKill (nto_node (), PIDGET (inferior_ptid), 0, SIGKILL, 0, 0);
      close (ctl_fd);
    }
  inferior_ptid = null_ptid;
  init_thread_list ();
  unpush_target (&procfs_ops);
  generic_mourn_inferior ();
  attach_flag = 0;
}

/* This function breaks up an argument string into an argument
   vector suitable for passing to execvp().
   E.g., on "run a b c d" this routine would get as input
   the string "a b c d", and as output it would fill in argv with
   the four arguments "a", "b", "c", "d".  The only additional
   functionality is simple quoting.  The gdb command:
  	run a "b c d" f
   will fill in argv with the three args "a", "b c d", "e".  */
static void
breakup_args (char *scratch, char **argv)
{
  char *pp, *cp = scratch;
  char quoting = 0;

  for (;;)
    {
      /* Scan past leading separators.  */
      quoting = 0;
      while (*cp == ' ' || *cp == '\t' || *cp == '\n')
	cp++;

      /* Break if at end of string.  */
      if (*cp == '\0')
	break;

      /* Take an arg.  */
      if (*cp == '"')
	{
	  cp++;
	  quoting = strchr (cp, '"') ? 1 : 0;
	}

      *argv++ = cp;

      /* Scan for next arg separator.  */
      pp = cp;
      if (quoting)
	cp = strchr (pp, '"');
      if ((cp == NULL) || (!quoting))
	cp = strchr (pp, ' ');
      if (cp == NULL)
	cp = strchr (pp, '\t');
      if (cp == NULL)
	cp = strchr (pp, '\n');

      /* No separators => end of string => break.  */
      if (cp == NULL)
	{
	  pp = cp;
	  break;
	}

      /* Replace the separator with a terminator.  */
      *cp++ = '\0';
    }

  /* Execv requires a null-terminated arg vector.  */
  *argv = NULL;
}

static void
procfs_create_inferior (char *exec_file, char *allargs, char **env,
			int from_tty)
{
  struct inheritance inherit;
  pid_t pid;
  int flags, errn;
  char **argv, *args;
  const char *in = "", *out = "", *err = "";
  int fd, fds[3];
  sigset_t set;
  const char *inferior_io_terminal = get_inferior_io_terminal ();

  argv = xmalloc (((strlen (allargs) + 1) / (unsigned) 2 + 2) *
		  sizeof (*argv));
  argv[0] = get_exec_file (1);
  if (!argv[0])
    {
      if (exec_file)
	argv[0] = exec_file;
      else
	return;
    }

  args = xstrdup (allargs);
  breakup_args (args, exec_file ? &argv[1] : &argv[0]);

  argv = nto_parse_redirection (argv, &in, &out, &err);

  fds[0] = STDIN_FILENO;
  fds[1] = STDOUT_FILENO;
  fds[2] = STDERR_FILENO;

  /* If the user specified I/O via gdb's --tty= arg, use it, but only
     if the i/o is not also being specified via redirection.  */
  if (inferior_io_terminal)
    {
      if (!in[0])
	in = inferior_io_terminal;
      if (!out[0])
	out = inferior_io_terminal;
      if (!err[0])
	err = inferior_io_terminal;
    }

  if (in[0])
    {
      fd = open (in, O_RDONLY);
      if (fd == -1)
	perror (in);
      else
	fds[0] = fd;
    }
  if (out[0])
    {
      fd = open (out, O_WRONLY);
      if (fd == -1)
	perror (out);
      else
	fds[1] = fd;
    }
  if (err[0])
    {
      fd = open (err, O_WRONLY);
      if (fd == -1)
	perror (err);
      else
	fds[2] = fd;
    }

  /* Clear any pending SIGUSR1's but keep the behavior the same.  */
  signal (SIGUSR1, signal (SIGUSR1, SIG_IGN));

  sigemptyset (&set);
  sigaddset (&set, SIGUSR1);
  sigprocmask (SIG_UNBLOCK, &set, NULL);

  memset (&inherit, 0, sizeof (inherit));

  if (ND_NODE_CMP (nto_procfs_node, ND_LOCAL_NODE) != 0)
    {
      inherit.nd = nto_node ();
      inherit.flags |= SPAWN_SETND;
      inherit.flags &= ~SPAWN_EXEC;
    }
  inherit.flags |= SPAWN_SETGROUP | SPAWN_HOLD;
  inherit.pgroup = SPAWN_NEWPGROUP;
  pid = spawnp (argv[0], 3, fds, &inherit, argv,
		ND_NODE_CMP (nto_procfs_node, ND_LOCAL_NODE) == 0 ? env : 0);
  xfree (args);

  sigprocmask (SIG_BLOCK, &set, NULL);

  if (pid == -1)
    error (_("Error spawning %s: %d (%s)"), argv[0], errno,
	   safe_strerror (errno));

  if (fds[0] != STDIN_FILENO)
    close (fds[0]);
  if (fds[1] != STDOUT_FILENO)
    close (fds[1]);
  if (fds[2] != STDERR_FILENO)
    close (fds[2]);

  inferior_ptid = do_attach (pid_to_ptid (pid));

  attach_flag = 0;
  flags = _DEBUG_FLAG_KLC;	/* Kill-on-Last-Close flag.  */
  errn = devctl (ctl_fd, DCMD_PROC_SET_FLAG, &flags, sizeof (flags), 0);
  if (errn != EOK)
    {
      /* FIXME: expected warning?  */
      /* warning( "Failed to set Kill-on-Last-Close flag: errno = %d(%s)\n",
         errn, strerror(errn) ); */
    }
  push_target (&procfs_ops);
  target_terminal_init ();

  if (exec_bfd != NULL
      || (symfile_objfile != NULL && symfile_objfile->obfd != NULL))
    solib_create_inferior_hook ();
  stop_soon = 0;
}

static void
procfs_stop (void)
{
  devctl (ctl_fd, DCMD_PROC_STOP, NULL, 0, 0);
}

static void
procfs_kill_inferior (void)
{
  target_mourn_inferior ();
}

/* Store register REGNO, or all registers if REGNO == -1, from the contents
   of REGISTERS.  */
static void
procfs_prepare_to_store (void)
{
}

/* Fill buf with regset and return devctl cmd to do the setting.  Return
   -1 if we fail to get the regset.  Store size of regset in regsize.  */
static int
get_regset (int regset, char *buf, int bufsize, int *regsize)
{
  int dev_get, dev_set;
  switch (regset)
    {
    case NTO_REG_GENERAL:
      dev_get = DCMD_PROC_GETGREG;
      dev_set = DCMD_PROC_SETGREG;
      break;

    case NTO_REG_FLOAT:
      dev_get = DCMD_PROC_GETFPREG;
      dev_set = DCMD_PROC_SETFPREG;
      break;

    case NTO_REG_ALT:
      dev_get = DCMD_PROC_GETALTREG;
      dev_set = DCMD_PROC_SETALTREG;
      break;

    case NTO_REG_SYSTEM:
    default:
      return -1;
    }
  if (devctl (ctl_fd, dev_get, &buf, bufsize, regsize) != EOK)
    return -1;

  return dev_set;
}

void
procfs_store_registers (int regno)
{
  union
  {
    procfs_greg greg;
    procfs_fpreg fpreg;
    procfs_altreg altreg;
  }
  reg;
  unsigned off;
  int len, regset, regsize, dev_set, err;
  char *data;

  if (ptid_equal (inferior_ptid, null_ptid))
    return;
  procfs_set_thread (inferior_ptid);

  if (regno == -1)
    {
      for (regset = NTO_REG_GENERAL; regset < NTO_REG_END; regset++)
	{
	  dev_set = get_regset (regset, (char *) &reg,
				sizeof (reg), &regsize);
	  if (dev_set == -1)
	    continue;

	  if (nto_regset_fill (regset, (char *) &reg) == -1)
	    continue;

	  err = devctl (ctl_fd, dev_set, &reg, regsize, 0);
	  if (err != EOK)
	    fprintf_unfiltered (gdb_stderr,
				"Warning unable to write regset %d: %s\n",
				regno, safe_strerror (err));
	}
    }
  else
    {
      regset = nto_regset_id (regno);
      if (regset == -1)
	return;

      dev_set = get_regset (regset, (char *) &reg, sizeof (reg), &regsize);
      if (dev_set == -1)
	return;

      len = nto_register_area (regno, regset, &off);

      if (len < 1)
	return;

      regcache_raw_collect (current_regcache, regno, (char *) &reg + off);

      err = devctl (ctl_fd, dev_set, &reg, regsize, 0);
      if (err != EOK)
	fprintf_unfiltered (gdb_stderr,
			    "Warning unable to write regset %d: %s\n", regno,
			    safe_strerror (err));
    }
}

static void
notice_signals (void)
{
  int signo;

  for (signo = 1; signo < NSIG; signo++)
    {
      if (signal_stop_state (target_signal_from_host (signo)) == 0
	  && signal_print_state (target_signal_from_host (signo)) == 0
	  && signal_pass_state (target_signal_from_host (signo)) == 1)
	sigdelset (&run.trace, signo);
      else
	sigaddset (&run.trace, signo);
    }
}

/* When the user changes the state of gdb's signal handling via the
   "handle" command, this function gets called to see if any change
   in the /proc interface is required.  It is also called internally
   by other /proc interface functions to initialize the state of
   the traced signal set.  */
static void
procfs_notice_signals (ptid_t ptid)
{
  sigemptyset (&run.trace);
  notice_signals ();
}

static struct tidinfo *
procfs_thread_info (pid_t pid, short tid)
{
/* NYI */
  return NULL;
}

char *
procfs_pid_to_str (ptid_t ptid)
{
  static char buf[1024];
  int pid, tid, n;
  struct tidinfo *tip;

  pid = ptid_get_pid (ptid);
  tid = ptid_get_tid (ptid);

  n = snprintf (buf, 1023, "process %d", pid);

#if 0				/* NYI */
  tip = procfs_thread_info (pid, tid);
  if (tip != NULL)
    snprintf (&buf[n], 1023, " (state = 0x%02x)", tip->state);
#endif

  return buf;
}

static void
init_procfs_ops (void)
{
  procfs_ops.to_shortname = "procfs";
  procfs_ops.to_longname = "QNX Neutrino procfs child process";
  procfs_ops.to_doc =
    "QNX Neutrino procfs child process (started by the \"run\" command).\n\
	target procfs <node>";
  procfs_ops.to_open = procfs_open;
  procfs_ops.to_attach = procfs_attach;
  procfs_ops.to_post_attach = procfs_post_attach;
  procfs_ops.to_detach = procfs_detach;
  procfs_ops.to_resume = procfs_resume;
  procfs_ops.to_wait = procfs_wait;
  procfs_ops.to_fetch_registers = procfs_fetch_registers;
  procfs_ops.to_store_registers = procfs_store_registers;
  procfs_ops.to_prepare_to_store = procfs_prepare_to_store;
  procfs_ops.deprecated_xfer_memory = procfs_xfer_memory;
  procfs_ops.to_files_info = procfs_files_info;
  procfs_ops.to_insert_breakpoint = procfs_insert_breakpoint;
  procfs_ops.to_remove_breakpoint = procfs_remove_breakpoint;
  procfs_ops.to_can_use_hw_breakpoint = procfs_can_use_hw_breakpoint;
  procfs_ops.to_insert_hw_breakpoint = procfs_insert_hw_breakpoint;
  procfs_ops.to_remove_hw_breakpoint = procfs_remove_breakpoint;
  procfs_ops.to_insert_watchpoint = procfs_insert_hw_watchpoint;
  procfs_ops.to_remove_watchpoint = procfs_remove_hw_watchpoint;
  procfs_ops.to_stopped_by_watchpoint = procfs_stopped_by_watchpoint;
  procfs_ops.to_terminal_init = terminal_init_inferior;
  procfs_ops.to_terminal_inferior = terminal_inferior;
  procfs_ops.to_terminal_ours_for_output = terminal_ours_for_output;
  procfs_ops.to_terminal_ours = terminal_ours;
  procfs_ops.to_terminal_info = child_terminal_info;
  procfs_ops.to_kill = procfs_kill_inferior;
  procfs_ops.to_create_inferior = procfs_create_inferior;
  procfs_ops.to_mourn_inferior = procfs_mourn_inferior;
  procfs_ops.to_can_run = procfs_can_run;
  procfs_ops.to_notice_signals = procfs_notice_signals;
  procfs_ops.to_thread_alive = procfs_thread_alive;
  procfs_ops.to_find_new_threads = procfs_find_new_threads;
  procfs_ops.to_pid_to_str = procfs_pid_to_str;
  procfs_ops.to_stop = procfs_stop;
  procfs_ops.to_stratum = process_stratum;
  procfs_ops.to_has_all_memory = 1;
  procfs_ops.to_has_memory = 1;
  procfs_ops.to_has_stack = 1;
  procfs_ops.to_has_registers = 1;
  procfs_ops.to_has_execution = 1;
  procfs_ops.to_magic = OPS_MAGIC;
  procfs_ops.to_have_continuable_watchpoint = 1;
}

#define OSTYPE_NTO 1

void
_initialize_procfs (void)
{
  sigset_t set;

  init_procfs_ops ();
  add_target (&procfs_ops);

  /* We use SIGUSR1 to gain control after we block waiting for a process.
     We use sigwaitevent to wait.  */
  sigemptyset (&set);
  sigaddset (&set, SIGUSR1);
  sigprocmask (SIG_BLOCK, &set, NULL);

  /* Set up trace and fault sets, as gdb expects them.  */
  sigemptyset (&run.trace);

  /* Stuff some information.  */
  nto_cpuinfo_flags = SYSPAGE_ENTRY (cpuinfo)->flags;
  nto_cpuinfo_valid = 1;

  add_info ("pidlist", procfs_pidlist, _("pidlist"));
  add_info ("meminfo", procfs_meminfo, _("memory information"));

  nto_is_nto_target = procfs_is_nto_target;
}


static int
procfs_hw_watchpoint (int addr, int len, int type)
{
  procfs_break brk;

  switch (type)
    {
    case 1:			/* Read.  */
      brk.type = _DEBUG_BREAK_RD;
      break;
    case 2:			/* Read/Write.  */
      brk.type = _DEBUG_BREAK_RW;
      break;
    default:			/* Modify.  */
/* FIXME: brk.type = _DEBUG_BREAK_RWM gives EINVAL for some reason.  */
      brk.type = _DEBUG_BREAK_RW;
    }
  brk.type |= _DEBUG_BREAK_HW;	/* Always ask for HW.  */
  brk.addr = addr;
  brk.size = len;

  errno = devctl (ctl_fd, DCMD_PROC_BREAK, &brk, sizeof (brk), 0);
  if (errno != EOK)
    {
      perror ("Failed to set hardware watchpoint");
      return -1;
    }
  return 0;
}

static int
procfs_can_use_hw_breakpoint (int type, int cnt, int othertype)
{
  return 1;
}

static int
procfs_remove_hw_watchpoint (CORE_ADDR addr, int len, int type)
{
  return procfs_hw_watchpoint (addr, -1, type);
}

static int
procfs_insert_hw_watchpoint (CORE_ADDR addr, int len, int type)
{
  return procfs_hw_watchpoint (addr, len, type);
}

static int
procfs_stopped_by_watchpoint (void)
{
  return 0;
}