[deliverable/binutils-gdb.git] / gdb / ocd.c

/* Remote target communications for the Macraigor Systems BDM Wiggler
   Copyright 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.  */

#include "defs.h"
#include "gdbcore.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 "gdbcmd.h"
#include "objfiles.h"
#include "gdb-stabs.h"
#include "dcache.h"
#include <sys/types.h>
#include <signal.h>
#include "serial.h"
#include "ocd.h"

/* Prototypes for local functions */

static int wiggler_write_bytes PARAMS ((CORE_ADDR memaddr,
				       char *myaddr, int len));

static int wiggler_read_bytes PARAMS ((CORE_ADDR memaddr,
				      char *myaddr, int len));

static int wiggler_start_remote PARAMS ((char *dummy));

static int readchar PARAMS ((int timeout));

static void reset_packet PARAMS ((void));

static void output_packet PARAMS ((void));

static int get_quoted_char PARAMS ((int timeout));

static void put_quoted_char PARAMS ((int c));

static void wiggler_interrupt PARAMS ((int signo));

static void wiggler_interrupt_twice PARAMS ((int signo));

static void interrupt_query PARAMS ((void));

static unsigned char * do_command PARAMS ((int cmd, int *statusp, int *lenp));

static void wiggler_put_packet PARAMS ((unsigned char *packet, int pktlen));

static unsigned char * wiggler_get_packet PARAMS ((int cmd, int *pktlen, int timeout));

static struct target_ops *current_ops = NULL;

static int last_run_status;

/* 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;

/* Descriptor for I/O to remote machine.  Initialize it to NULL so that
   wiggler_open knows that we don't have a file open when the program
   starts.  */
static serial_t wiggler_desc = NULL;
\f
void
wiggler_error (s, error_code)
     char *s;
     int error_code;
{
  char buf[100];

  fputs_filtered (s, gdb_stderr);
  fputs_filtered (" ", gdb_stderr);

  switch (error_code)
    {
    case 0x1: s = "Unknown fault"; break;
    case 0x2: s = "Power failed"; break;
    case 0x3: s = "Cable disconnected"; break;
    case 0x4: s = "Couldn't enter BDM"; break;
    case 0x5: s = "Target stuck in reset"; break;
    case 0x6: s = "Port not configured"; break;
    case 0x7: s = "Write verify failed"; break;
    case 0x11: s = "Bus error"; break;
    case 0x12: s = "Checksum error"; break;
    case 0x13: s = "Illegal command"; break;
    case 0x14: s = "Parameter error"; break;
    case 0x15: s = "Internal error"; break;
    case 0x16: s = "Register buffer error"; break;
    case 0x80: s = "Flash erase error"; break;
    default:
      sprintf (buf, "Unknown error code %d", error_code);
      s = buf;
    }

  error (s);
}

/*  Return nonzero if the thread TH is still alive on the remote system.  */

int
wiggler_thread_alive (th)
     int th;
{
  return 1;
}
\f
/* Clean up connection to a remote debugger.  */

/* ARGSUSED */
void
wiggler_close (quitting)
     int quitting;
{
  if (wiggler_desc)
    SERIAL_CLOSE (wiggler_desc);
  wiggler_desc = NULL;
}

/* Stub for catch_errors.  */

static int
wiggler_start_remote (dummy)
     char *dummy;
{
  unsigned char buf[10], *p;
  int pktlen;
  int status;
  int error_code;
  int speed;
  enum wiggler_target_type target_type;

  target_type = (enum wiggler_target_type)dummy;

  immediate_quit = 1;		/* Allow user to interrupt it */

  SERIAL_SEND_BREAK (wiggler_desc); /* Wake up the wiggler */

  do_command (WIGGLER_AYT, &status, &pktlen);

  p = do_command (WIGGLER_GET_VERSION, &status, &pktlen);

  printf_unfiltered ("[Wiggler version %x.%x, capability 0x%x]\n",
		     p[0], p[1], (p[2] << 16) | p[3]);

#if 1
  speed = 80;			/* Divide clock by 4000 */

  buf[0] = WIGGLER_INIT;
  buf[1] = speed >> 8;
  buf[2] = speed & 0xff;
  buf[3] = target_type;
  wiggler_put_packet (buf, 4);	/* Init Wiggler params */
  p = wiggler_get_packet (buf[0], &pktlen, remote_timeout);

  if (pktlen < 2)
    error ("Truncated response packet from Wiggler");

  status = p[1];
  error_code = p[2];

  if (error_code != 0)
    wiggler_error ("WIGGLER_INIT:", error_code);
#endif

#if 0
  /* Reset the target */

  do_command (WIGGLER_RESET_RUN, &status, &pktlen);
/*  do_command (WIGGLER_RESET, &status, &pktlen);*/
#endif

  /* If processor is still running, stop it.  */

  if (!(status & WIGGLER_FLAG_BDM))
    wiggler_stop ();

#if 1
  buf[0] = WIGGLER_SET_CTL_FLAGS;
  buf[1] = 0;
  buf[2] = 1;		/* Asynchronously return status when target stops */
  wiggler_put_packet (buf, 3);

  p = wiggler_get_packet (buf[0], &pktlen, remote_timeout);

  if (pktlen < 2)
    error ("Truncated response packet from Wiggler");

  status = p[1];
  error_code = p[2];

  if (error_code != 0)
    wiggler_error ("WIGGLER_SET_CTL_FLAGS:", error_code);
#endif

  immediate_quit = 0;

/* This is really the job of start_remote however, that makes an assumption
   that the target is about to print out a status message of some sort.  That
   doesn't happen here (in fact, it may not be possible to get the monitor to
   send the appropriate packet).  */

  flush_cached_frames ();
  registers_changed ();
  stop_pc = read_pc ();
  set_current_frame (create_new_frame (read_fp (), stop_pc));
  select_frame (get_current_frame (), 0);
  print_stack_frame (selected_frame, -1, 1);

  return 1;
}

/* Open a connection to a remote debugger.
   NAME is the filename used for communication.  */

static DCACHE *wiggler_dcache;

void
wiggler_open (name, from_tty, target_type, ops)
     char *name;
     int from_tty;
     enum wiggler_target_type target_type;
     struct target_ops *ops;
{
  if (name == 0)
    error ("To open a Wiggler connection, you need to specify what serial\n\
device the Wiggler is attached to (e.g. /dev/ttya).");

  target_preopen (from_tty);

  current_ops = ops;

  unpush_target (current_ops);

  wiggler_dcache = dcache_init (wiggler_read_bytes, wiggler_write_bytes);

  wiggler_desc = SERIAL_OPEN (name);
  if (!wiggler_desc)
    perror_with_name (name);

  if (baud_rate != -1)
    {
      if (SERIAL_SETBAUDRATE (wiggler_desc, baud_rate))
	{
	  SERIAL_CLOSE (wiggler_desc);
	  perror_with_name (name);
	}
    }

  SERIAL_RAW (wiggler_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 (wiggler_desc);

  if (from_tty)
    {
      puts_filtered ("Remote target wiggler connected to ");
      puts_filtered (name);
      puts_filtered ("\n");
    }
  push_target (current_ops);	/* Switch to using remote target now */

  /* 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 (wiggler_start_remote, (char *)target_type,
		     "Couldn't establish connection to remote target\n", RETURN_MASK_ALL))
    pop_target();
}

/* 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.  */

void
wiggler_detach (args, from_tty)
     char *args;
     int from_tty;
{
  if (args)
    error ("Argument given to \"detach\" when remotely debugging.");

  pop_target ();
  if (from_tty)
    puts_filtered ("Ending remote debugging.\n");
}
\f
/* Tell the remote machine to resume.  */

void
wiggler_resume (pid, step, siggnal)
     int pid, step;
     enum target_signal siggnal;
{
  int pktlen;

  dcache_flush (wiggler_dcache);

  if (step)
    do_command (WIGGLER_STEP, &last_run_status, &pktlen);
  else
    do_command (WIGGLER_RUN, &last_run_status, &pktlen);
}
\f
void
wiggler_stop ()
{
  int status;
  int pktlen;

  do_command (WIGGLER_STOP, &status, &pktlen);

  if (!(status & WIGGLER_FLAG_BDM))
    error ("Can't stop target via BDM");
}

static volatile int wiggler_interrupt_flag;

/* Send ^C to target to halt it.  Target will respond, and send us a
   packet.  */

static void
wiggler_interrupt (signo)
     int signo;
{
  /* If this doesn't work, try more severe steps.  */
  signal (signo, wiggler_interrupt_twice);
  
  if (remote_debug)
    printf_unfiltered ("wiggler_interrupt called\n");

  {
    char buf[1];

    wiggler_stop ();
    buf[0] = WIGGLER_AYT;
    wiggler_put_packet (buf, 1);
    wiggler_interrupt_flag = 1;
  }
}

static void (*ofunc)();

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

  signal (signo, wiggler_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.  */
static int kill_kludge;

/* 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).  */

int
wiggler_wait ()
{
  unsigned char *p;
  int error_code, status;
  int pktlen;

  wiggler_interrupt_flag = 0;

  /* Target may already be stopped by the time we get here. */

  if (!(last_run_status & WIGGLER_FLAG_BDM))
    {
      ofunc = (void (*)()) signal (SIGINT, wiggler_interrupt);

      p = wiggler_get_packet (WIGGLER_AYT, &pktlen, -1);

      signal (SIGINT, ofunc);

      if (pktlen < 2)
	error ("Truncated response packet from Wiggler");

      status = p[1];
      error_code = p[2];

      if (error_code != 0)
	wiggler_error ("target_wait:", error_code);

      if (status & WIGGLER_FLAG_PWF)
	error ("Wiggler lost VCC at BDM interface.");
      else if (status & WIGGLER_FLAG_CABLE_DISC)
	error ("BDM cable appears to have been disconnected.");

      if (!(status & WIGGLER_FLAG_BDM))
	error ("Wiggler woke up, but wasn't stopped: 0x%x", status);
    }

  if (wiggler_interrupt_flag)
    return 1;
  else
    return 0;
}

/* Read registers from the Wiggler.  Specify the starting and ending register
   number.  Return the number of regs actually read in *NUMREGS.  Returns a
   pointer to a static array containing the register contents.  */

unsigned char *
wiggler_read_bdm_registers (first_bdm_regno, last_bdm_regno, reglen)
     int first_bdm_regno;
     int last_bdm_regno;
     int *reglen;
{
  unsigned char buf[10];
  int i;
  unsigned char *p;
  unsigned char *regs;
  int error_code, status;
  int pktlen;

  buf[0] = WIGGLER_READ_REGS;
  buf[1] = first_bdm_regno >> 8;
  buf[2] = first_bdm_regno & 0xff;
  buf[3] = last_bdm_regno >> 8;
  buf[4] = last_bdm_regno & 0xff;

  wiggler_put_packet (buf, 5);
  p = wiggler_get_packet (WIGGLER_READ_REGS, &pktlen, remote_timeout);

  status = p[1];
  error_code = p[2];

  if (error_code != 0)
    wiggler_error ("read_bdm_registers:", error_code);

  i = p[3];
  if (i == 0)
    i = 256;

  if (i > pktlen - 4
      || ((i & 3) != 0))
    error ("Register block size bad:  %d", i);

  *reglen = i;

  regs = p + 4;

  return regs;
}

/* Read register BDM_REGNO and returns its value ala read_register() */

CORE_ADDR
wiggler_read_bdm_register (bdm_regno)
     int bdm_regno;
{
  int reglen;
  unsigned char *p;
  CORE_ADDR regval;

  p = wiggler_read_bdm_registers (bdm_regno, bdm_regno, &reglen);
  regval = extract_unsigned_integer (p, reglen);

  return regval;
}

void
wiggler_write_bdm_registers (first_bdm_regno, regptr, reglen)
     int first_bdm_regno;
     unsigned char *regptr;
     int reglen;
{
  unsigned char *buf;
  unsigned char *p;
  int error_code, status;
  int pktlen;

  buf = alloca (4 + reglen);

  buf[0] = WIGGLER_WRITE_REGS;
  buf[1] = first_bdm_regno >> 8;
  buf[2] = first_bdm_regno & 0xff;
  buf[3] = reglen;
  memcpy (buf + 4, regptr, reglen);

  wiggler_put_packet (buf, 4 + reglen);
  p = wiggler_get_packet (WIGGLER_WRITE_REGS, &pktlen, remote_timeout);

  if (pktlen < 3)
    error ("Truncated response packet from Wiggler");

  status = p[1];
  error_code = p[2];

  if (error_code != 0)
    wiggler_error ("wiggler_write_bdm_registers:", error_code);
}

void
wiggler_write_bdm_register (bdm_regno, reg)
     int bdm_regno;
     CORE_ADDR reg;
{
  unsigned char buf[4];

  store_unsigned_integer (buf, 4, reg);

  wiggler_write_bdm_registers (bdm_regno, buf, 4);
}
\f
void 
wiggler_prepare_to_store ()
{
}
\f
/* 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 write_mem_command = WIGGLER_WRITE_MEM;

static int
wiggler_write_bytes (memaddr, myaddr, len)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
{
  char buf[256 + 10];
  unsigned char *p;
  int origlen;

  origlen = len;

  buf[0] = write_mem_command;
  buf[5] = 1;			/* Write as bytes */
  buf[6] = 0;			/* Don't verify */

  while (len > 0)
    {
      int numbytes;
      int pktlen;
      int status, error_code;

      numbytes = min (len, 256 - 8);

      buf[1] = memaddr >> 24;
      buf[2] = memaddr >> 16;
      buf[3] = memaddr >> 8;
      buf[4] = memaddr;

      buf[7] = numbytes;

      memcpy (&buf[8], myaddr, numbytes);
      wiggler_put_packet (buf, 8 + numbytes);
      p = wiggler_get_packet (WIGGLER_WRITE_MEM, &pktlen, remote_timeout);
      if (pktlen < 3)
	error ("Truncated response packet from Wiggler");

      status = p[1];
      error_code = p[2];

      if (error_code == 0x11)	/* Got a bus error? */
	{
	  CORE_ADDR error_address;

	  error_address = p[3] << 24;
	  error_address |= p[4] << 16;
	  error_address |= p[5] << 8;
	  error_address |= p[6];
	  numbytes = error_address - memaddr;

	  len -= numbytes;

	  errno = EIO;

	  break;
	}
      else if (error_code != 0)
	wiggler_error ("wiggler_write_bytes:", error_code);

      len -= numbytes;
      memaddr += numbytes;
      myaddr += numbytes;
    }

  return origlen - len;
}

/* 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
wiggler_read_bytes (memaddr, myaddr, len)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
{
  char buf[256 + 10];
  unsigned char *p;
  int origlen;

  origlen = len;

  buf[0] = WIGGLER_READ_MEM;
  buf[5] = 1;			/* Read as bytes */

  while (len > 0)
    {
      int numbytes;
      int pktlen;
      int status, error_code;

      numbytes = min (len, 256 - 7);

      buf[1] = memaddr >> 24;
      buf[2] = memaddr >> 16;
      buf[3] = memaddr >> 8;
      buf[4] = memaddr;

      buf[6] = numbytes;

      wiggler_put_packet (buf, 7);
      p = wiggler_get_packet (WIGGLER_READ_MEM, &pktlen, remote_timeout);
      if (pktlen < 4)
	error ("Truncated response packet from Wiggler");

      status = p[1];
      error_code = p[2];

      if (error_code == 0x11)	/* Got a bus error? */
	{
	  CORE_ADDR error_address;

	  error_address = p[3] << 24;
	  error_address |= p[4] << 16;
	  error_address |= p[5] << 8;
	  error_address |= p[6];
	  numbytes = error_address - memaddr;

	  len -= numbytes;

	  errno = EIO;

	  break;
	}
      else if (error_code != 0)
	wiggler_error ("wiggler_read_bytes:", error_code);

      memcpy (myaddr, &p[4], numbytes);

      len -= numbytes;
      memaddr += numbytes;
      myaddr += numbytes;
    }

  return origlen - len;
}
\f
/* 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 */
int
wiggler_xfer_memory (memaddr, myaddr, len, should_write, target)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
     int should_write;
     struct target_ops *target;			/* ignored */
{
  return dcache_xfer_memory (wiggler_dcache, memaddr, myaddr, len, should_write);
}
\f
void
wiggler_files_info (ignore)
     struct target_ops *ignore;
{
  puts_filtered ("Debugging a target over a serial line.\n");
}
\f
/* 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 side, handling wierd errors. */

static int
readchar (timeout)
     int timeout;
{
  int ch;

  ch = SERIAL_READCHAR (wiggler_desc, timeout);

  switch (ch)
    {
    case SERIAL_EOF:
      error ("Remote connection closed");
    case SERIAL_ERROR:
      perror_with_name ("Remote communication error");
    case SERIAL_TIMEOUT:
    default:
      return ch;
    }
}

#if 0
/* Read a character from the data stream, dequoting as necessary.  SYN is
   treated special.  Any SYNs appearing in the data stream are returned as the
   distinct value RAW_SYN (which has a value > 8 bits and therefore cannot be
   mistaken for real data).  */

static int
get_quoted_char (timeout)
     int timeout;
{
  int ch;

  ch = readchar (timeout);

  switch (ch)
    {
    case SERIAL_TIMEOUT:
      error ("Timeout in mid-packet, aborting");
    case SYN:
      return RAW_SYN;
    case DLE:
      ch = readchar (timeout);
      if (ch == SYN)
	return RAW_SYN;
      return ch & ~0100;
    default:
      return ch;
    }
}

static unsigned char pkt[256 * 2 + 10], *pktp; /* Worst case */

static void
reset_packet ()
{
  pktp = pkt;
}

static void
output_packet ()
{
  if (SERIAL_WRITE (wiggler_desc, pkt, pktp - pkt))
    perror_with_name ("output_packet: write failed");

  reset_packet ();
}

/* Output a quoted character.  SYNs and DLEs are quoted.  Everything else goes
   through untouched.  */

static void
put_quoted_char (c)
     int c;
{
  switch (c)
    {
    case SYN:
    case DLE:
      *pktp++ = DLE;
      c |= 0100;
    }

  *pktp++ = c;
}

/* Send a packet to the Wiggler.  The packet framed by a SYN character, a byte
   count and a checksum.  The byte count only counts the number of bytes
   between the count and the checksum.  A count of zero actually means 256.
   Any SYNs within the packet (including the checksum and count) must be
   quoted.  The quote character must be quoted as well.  Quoting is done by
   replacing the character with the two-character sequence DLE, {char} | 0100.
   Note that the quoting mechanism has no effect on the byte count.
 */

static void
stu_put_packet (buf, len)
     unsigned char *buf;
     int len;
{
  unsigned char checksum;
  unsigned char c;

  if (len == 0 || len > 256)
    abort ();			/* Can't represent 0 length packet */

  reset_packet ();

  checksum = 0;

  put_quoted_char (RAW_SYN);

  c = len;

  do
    {
      checksum += c;

      put_quoted_char (c);

      c = *buf++;
    }
  while (len-- > 0);

  put_quoted_char (-checksum & 0xff);

  output_packet ();
}

#else

/* Send a packet to the Wiggler.  The packet framed by a SYN character, a byte
   count and a checksum.  The byte count only counts the number of bytes
   between the count and the checksum.  A count of zero actually means 256.
   Any SYNs within the packet (including the checksum and count) must be
   quoted.  The quote character must be quoted as well.  Quoting is done by
   replacing the character with the two-character sequence DLE, {char} | 0100.
   Note that the quoting mechanism has no effect on the byte count.
 */

static void
wiggler_put_packet (buf, len)
     unsigned char *buf;
     int len;
{
  unsigned char checksum;
  unsigned char c;
  unsigned char *packet, *packet_ptr;

  packet = alloca (len + 1 + 1); /* packet + SYN + checksum */
  packet_ptr = packet;

  checksum = 0;

  *packet_ptr++ = 0x55;

  while (len-- > 0)
    {
      c = *buf++;

      checksum += c;
      *packet_ptr++ = c;
    }

  *packet_ptr++ = -checksum;
  if (SERIAL_WRITE (wiggler_desc, packet, packet_ptr - packet))
    perror_with_name ("output_packet: write failed");
}
#endif

#if 0
/* Get a packet from the Wiggler.  Timeout is only enforced for the first byte
   of the packet.  Subsequent bytes are expected to arrive in time <= 
   remote_timeout.  Returns a pointer to a static buffer containing the payload
   of the packet.  *LENP contains the length of the packet.
*/

static unsigned char *
stu_get_packet (cmd, lenp, timeout)
     unsigned char cmd;
     int *lenp;
{
  int ch;
  int len;
  static unsigned char buf[256 + 10], *p;
  unsigned char checksum;

 find_packet:

  ch = get_quoted_char (timeout);

  if (ch < 0)
    error ("get_packet (readchar): %d", ch);

  if (ch != RAW_SYN)
    goto find_packet;

 found_syn:			/* Found the start of a packet */

  p = buf;
  checksum = 0;

  len = get_quoted_char (remote_timeout);

  if (len == RAW_SYN)
    goto found_syn;

  checksum += len;

  if (len == 0)
    len = 256;

  len++;			/* Include checksum */

  while (len-- > 0)
    {
      ch = get_quoted_char (remote_timeout);
      if (ch == RAW_SYN)
	goto found_syn;

      *p++ = ch;
      checksum += ch;
    }

  if (checksum != 0)
    goto find_packet;

  if (cmd != buf[0])
    error ("Response phase error.  Got 0x%x, expected 0x%x", buf[0], cmd);

  *lenp = p - buf - 1;
  return buf;
}

#else

/* Get a packet from the Wiggler.  Timeout is only enforced for the first byte
   of the packet.  Subsequent bytes are expected to arrive in time <= 
   remote_timeout.  Returns a pointer to a static buffer containing the payload
   of the packet.  *LENP contains the length of the packet.
*/

static unsigned char *
wiggler_get_packet (cmd, lenp, timeout)
     int cmd;
     int *lenp;
{
  int ch;
  int len;
  int i;
  static unsigned char packet[512];
  unsigned char *packet_ptr;
  unsigned char checksum;

 find_packet:

  ch = readchar (timeout);

  if (ch < 0)
    error ("wiggler_get_packet (readchar): %d", ch);

  if (ch != 0x55)
    goto find_packet;

/* Found the start of a packet */

  packet_ptr = packet;
  checksum = 0;

/* Read command char.  That sort of tells us how long the packet is. */

  ch = readchar (timeout);

  if (ch < 0)
    error ("wiggler_get_packet (readchar): %d", ch);

  *packet_ptr++ = ch;
  checksum += ch;

/* Get status. */

  ch = readchar (timeout);

  if (ch < 0)
    error ("wiggler_get_packet (readchar): %d", ch);
  *packet_ptr++ = ch;
  checksum += ch;

/* Get error code. */

  ch = readchar (timeout);

  if (ch < 0)
    error ("wiggler_get_packet (readchar): %d", ch);
  *packet_ptr++ = ch;
  checksum += ch;

  switch (ch)			/* Figure out length of packet */
    {
    case 0x7:			/* Write verify error? */
      len = 8;			/* write address, value read back */
      break;
    case 0x11:			/* Bus error? */
				/* write address, read flag */
    case 0x15:			/* Internal error */
      len = 5;			/* error code, vector */
      break;
    default:			/* Error w/no params */
      len = 0;
      break;
    case 0x0:			/* Normal result */
      switch (packet[0])
	{
	case WIGGLER_AYT:	/* Are You There? */
	case WIGGLER_SET_BAUD_RATE: /* Set Baud Rate */
	case WIGGLER_INIT:	/* Initialize wiggler */
	case WIGGLER_SET_SPEED:	/* Set Speed */
	case WIGGLER_SET_FUNC_CODE: /* Set Function Code */
	case WIGGLER_SET_CTL_FLAGS: /* Set Control Flags */
	case WIGGLER_SET_BUF_ADDR: /* Set Register Buffer Address */
	case WIGGLER_RUN:	/* Run Target from PC  */
	case WIGGLER_RUN_ADDR:	/* Run Target from Specified Address  */
	case WIGGLER_STOP:	/* Stop Target */
	case WIGGLER_RESET_RUN:	/* Reset Target and Run */
	case WIGGLER_RESET:	/* Reset Target and Halt */
	case WIGGLER_STEP:	/* Single Step */
	case WIGGLER_WRITE_REGS: /* Write Register */
	case WIGGLER_WRITE_MEM:	/* Write Memory */
	case WIGGLER_FILL_MEM:	/* Fill Memory */
	case WIGGLER_MOVE_MEM:	/* Move Memory */
	case WIGGLER_WRITE_INT_MEM: /* Write Internal Memory */
	case WIGGLER_JUMP:	/* Jump to Subroutine */
	case WIGGLER_ERASE_FLASH: /* Erase flash memory */
	case WIGGLER_PROGRAM_FLASH: /* Write flash memory */
	case WIGGLER_EXIT_MON:	/* Exit the flash programming monitor  */
	case WIGGLER_ENTER_MON:	/* Enter the flash programming monitor  */
	  len = 0;
	  break;
	case WIGGLER_GET_VERSION: /* Get Version */
	  len = 10;
	  break;
	case WIGGLER_GET_STATUS_MASK: /* Get Status Mask */
	  len = 1;
	  break;
	case WIGGLER_GET_CTRS:	/* Get Error Counters */
	case WIGGLER_READ_REGS:	/* Read Register */
	case WIGGLER_READ_MEM:	/* Read Memory */
	case WIGGLER_READ_INT_MEM: /* Read Internal Memory */
	  len = 257;
	  break;
	default:
	  fprintf_filtered (gdb_stderr, "Unknown packet type 0x%x\n", ch);
	  goto find_packet;
	}
    }

  if (len == 257)		/* Byte stream? */
    {				/* Yes, byte streams contain the length */
      ch = readchar (timeout);

      if (ch < 0)
	error ("wiggler_get_packet (readchar): %d", ch);
      *packet_ptr++ = ch;
      checksum += ch;
      len = ch;
      if (len == 0)
	len = 256;
    }

  while (len-- >= 0)		/* Do rest of packet and checksum */
    {
      ch = readchar (timeout);

      if (ch < 0)
	error ("wiggler_get_packet (readchar): %d", ch);
      *packet_ptr++ = ch;
      checksum += ch;
    }

  if (checksum != 0)
    goto find_packet;

  if (cmd != -1 && cmd != packet[0])
    error ("Response phase error.  Got 0x%x, expected 0x%x", packet[0], cmd);

  *lenp = packet_ptr - packet - 1; /* Subtract checksum byte */
  return packet;
}
#endif

/* Execute a simple (one-byte) command.  Returns a pointer to the data
   following the error code.  */

static unsigned char *
do_command (cmd, statusp, lenp)
     int cmd;
     int *statusp;
     int *lenp;
{
  unsigned char buf[100], *p;
  int status, error_code;
  char errbuf[100];

  buf[0] = cmd;
  wiggler_put_packet (buf, 1);		/* Send command */
  p = wiggler_get_packet (*buf, lenp, remote_timeout);

  if (*lenp < 3)
    error ("Truncated response packet from Wiggler");

  status = p[1];
  error_code = p[2];

  if (error_code != 0)
    {
      sprintf (errbuf, "do_command (0x%x):", cmd);
      wiggler_error (errbuf, error_code);
    }

  if (status & WIGGLER_FLAG_PWF)
    error ("Wiggler can't detect VCC at BDM interface.");
  else if (status & WIGGLER_FLAG_CABLE_DISC)
    error ("BDM cable appears to be disconnected.");

  *statusp = status;

  return p + 3;
}
\f
void
wiggler_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;
    }

  /* Don't wait for it to die.  I'm not really sure it matters whether
     we do or not.  */
  target_mourn_inferior ();
}

void
wiggler_mourn ()
{
  unpush_target (current_ops);
  generic_mourn_inferior ();
}

/* All we actually do is set the PC to the start address of exec_bfd, and start
   the program at that point.  */

void
wiggler_create_inferior (exec_file, args, env)
     char *exec_file;
     char *args;
     char **env;
{
  if (args && (*args != '\000'))
    error ("Args are not supported by BDM.");

  clear_proceed_status ();
  proceed (bfd_get_start_address (exec_bfd), TARGET_SIGNAL_0, 0);
}

void
wiggler_load (args, from_tty)
     char *args;
     int from_tty;
{
  generic_load (args, from_tty);

  inferior_pid = 0;

/* This is necessary because many things were based on the PC at the time that
   we attached to the monitor, which is no longer valid now that we have loaded
   new code (and just changed the PC).  Another way to do this might be to call
   normal_stop, except that the stack may not be valid, and things would get
   horribly confused... */

  clear_symtab_users ();
}

/* BDM (at least on CPU32) uses a different breakpoint */

static int
wiggler_insert_breakpoint (addr, contents_cache)
     CORE_ADDR addr;
     char *contents_cache;
{
  static char break_insn[] = {BDM_BREAKPOINT};
  int val;

  val = target_read_memory (addr, contents_cache, sizeof break_insn);

  if (val == 0)
    val = target_write_memory (addr, break_insn, sizeof break_insn);

  return val;
}

static void
bdm_command (args, from_tty)
     char *args;
     int from_tty;
{
  error ("bdm command must be followed by `reset'");
}

static void
bdm_reset_command (args, from_tty)
     char *args;
     int from_tty;
{
  int status, pktlen;

  if (!wiggler_desc)
    error ("Not connected to wiggler.");

  do_command (WIGGLER_RESET, &status, &pktlen);
  dcache_flush (wiggler_dcache);
  registers_changed ();
}

static void
bdm_restart_command (args, from_tty)
     char *args;
     int from_tty;
{
  int status, pktlen;

  if (!wiggler_desc)
    error ("Not connected to wiggler.");

  do_command (WIGGLER_RESET_RUN, &status, &pktlen);
  last_run_status = status;
  clear_proceed_status ();
  wait_for_inferior ();
  normal_stop ();
}

/* Temporary replacement for target_store_registers().  This prevents
   generic_load from trying to set the PC.  */

static void
noop_store_registers (regno)
     int regno;
{
}

static void
bdm_update_flash_command (args, from_tty)
     char *args;
     int from_tty;
{
  int status, pktlen;
  struct cleanup *old_chain;
  void (*store_registers_tmp) PARAMS ((int));

  if (!wiggler_desc)
    error ("Not connected to wiggler.");

  if (!args)
    error ("Must specify file containing new Wiggler code.");

/*  old_chain = make_cleanup (flash_cleanup, 0);*/

  do_command (WIGGLER_ENTER_MON, &status, &pktlen);

  do_command (WIGGLER_ERASE_FLASH, &status, &pktlen);

  write_mem_command = WIGGLER_PROGRAM_FLASH;
  store_registers_tmp = current_target.to_store_registers;
  current_target.to_store_registers = noop_store_registers;

  generic_load (args, from_tty);

  current_target.to_store_registers = store_registers_tmp;
  write_mem_command = WIGGLER_WRITE_MEM;

  do_command (WIGGLER_EXIT_MON, &status, &pktlen);

/*  discard_cleanups (old_chain);*/
}

static void
bdm_read_register_command (args, from_tty)
     char *args;
     int from_tty;
{
  /* XXX repeat should go on to the next register */

  if (!wiggler_desc)
    error ("Not connected to wiggler.");

  if (!args)
    error ("Must specify BDM register number.");

}
\f
void
_initialize_remote_wiggler ()
{
  extern struct cmd_list_element *cmdlist;
  static struct cmd_list_element *bdm_cmd_list = NULL;

  add_show_from_set (add_set_cmd ("remotetimeout", no_class,
				  var_integer, (char *)&remote_timeout,
				  "Set timeout value for remote read.\n", &setlist),
		     &showlist);

  add_prefix_cmd ("bdm", class_obscure, bdm_command, "", &bdm_cmd_list, "bdm ",
		  0, &cmdlist);

  add_cmd ("reset", class_obscure, bdm_reset_command, "", &bdm_cmd_list);
  add_cmd ("restart", class_obscure, bdm_restart_command, "", &bdm_cmd_list);
  add_cmd ("update-flash", class_obscure, bdm_update_flash_command, "", &bdm_cmd_list);
  /*  add_cmd ("read-register", class_obscure, bdm_read_register_command, "", &bdm_cmd_list);*/
}