gdb/

2012-03-08  Tristan Gingold  <gingold@adacore.com>

	* sparc-stub.c: Move to stubs/
	* sh-stub.c: Likewise.
	* m68k-stub.c: Likewise.
	* m32r-stub.c: Likewise.
	* i386-stub.c: Likewise.

gdb/stubs/
2012-03-08  Tristan Gingold  <gingold@adacore.com>

	* sparc-stub.c: Move from ..
	* sh-stub.c: Likewise.
	* m68k-stub.c: Likewise.
	* m32r-stub.c: Likewise.
	* i386-stub.c: Likewise.

6 files changed, 6198 insertions, 0 deletions

diff --git a/gdb/stubs/ChangeLog b/gdb/stubs/ChangeLog
index 1a8b2b702b3..a0f175e30df 100644
--- a/gdb/stubs/ChangeLog
+++ b/gdb/stubs/ChangeLog
@@ -1,3 +1,11 @@
+2012-03-08  Tristan Gingold  <gingold@adacore.com>
+
+	* sparc-stub.c: Move from ..
+	* sh-stub.c: Likewise.
+	* m68k-stub.c: Likewise.
+	* m32r-stub.c: Likewise.
+	* i386-stub.c: Likewise.
+
 2012-03-05  Tristan Gingold  <gingold@adacore.com>
 
 	* buildvms.com: New file.
diff --git a/gdb/stubs/i386-stub.c b/gdb/stubs/i386-stub.c
new file mode 100644
index 00000000000..04996b75cf6
--- /dev/null
+++ b/gdb/stubs/i386-stub.c
@@ -0,0 +1,952 @@
+/****************************************************************************
+
+		THIS SOFTWARE IS NOT COPYRIGHTED
+
+   HP offers the following for use in the public domain.  HP makes no
+   warranty with regard to the software or it's performance and the
+   user accepts the software "AS IS" with all faults.
+
+   HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
+   TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+
+****************************************************************************/
+
+/****************************************************************************
+ *  Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
+ *
+ *  Module name: remcom.c $
+ *  Revision: 1.34 $
+ *  Date: 91/03/09 12:29:49 $
+ *  Contributor:     Lake Stevens Instrument Division$
+ *
+ *  Description:     low level support for gdb debugger. $
+ *
+ *  Considerations:  only works on target hardware $
+ *
+ *  Written by:      Glenn Engel $
+ *  ModuleState:     Experimental $
+ *
+ *  NOTES:           See Below $
+ *
+ *  Modified for 386 by Jim Kingdon, Cygnus Support.
+ *
+ *  To enable debugger support, two things need to happen.  One, a
+ *  call to set_debug_traps() is necessary in order to allow any breakpoints
+ *  or error conditions to be properly intercepted and reported to gdb.
+ *  Two, a breakpoint needs to be generated to begin communication.  This
+ *  is most easily accomplished by a call to breakpoint().  Breakpoint()
+ *  simulates a breakpoint by executing a trap #1.
+ *
+ *  The external function exceptionHandler() is
+ *  used to attach a specific handler to a specific 386 vector number.
+ *  It should use the same privilege level it runs at.  It should
+ *  install it as an interrupt gate so that interrupts are masked
+ *  while the handler runs.
+ *
+ *  Because gdb will sometimes write to the stack area to execute function
+ *  calls, this program cannot rely on using the supervisor stack so it
+ *  uses it's own stack area reserved in the int array remcomStack.
+ *
+ *************
+ *
+ *    The following gdb commands are supported:
+ *
+ * command          function                               Return value
+ *
+ *    g             return the value of the CPU registers  hex data or ENN
+ *    G             set the value of the CPU registers     OK or ENN
+ *
+ *    mAA..AA,LLLL  Read LLLL bytes at address AA..AA      hex data or ENN
+ *    MAA..AA,LLLL: Write LLLL bytes at address AA.AA      OK or ENN
+ *
+ *    c             Resume at current address              SNN   ( signal NN)
+ *    cAA..AA       Continue at address AA..AA             SNN
+ *
+ *    s             Step one instruction                   SNN
+ *    sAA..AA       Step one instruction from AA..AA       SNN
+ *
+ *    k             kill
+ *
+ *    ?             What was the last sigval ?             SNN   (signal NN)
+ *
+ * All commands and responses are sent with a packet which includes a
+ * checksum.  A packet consists of
+ *
+ * $<packet info>#<checksum>.
+ *
+ * where
+ * <packet info> :: <characters representing the command or response>
+ * <checksum>    :: < two hex digits computed as modulo 256 sum of <packetinfo>>
+ *
+ * When a packet is received, it is first acknowledged with either '+' or '-'.
+ * '+' indicates a successful transfer.  '-' indicates a failed transfer.
+ *
+ * Example:
+ *
+ * Host:                  Reply:
+ * $m0,10#2a               +$00010203040506070809101112131415#42
+ *
+ ****************************************************************************/
+
+#include <stdio.h>
+#include <string.h>
+
+/************************************************************************
+ *
+ * external low-level support routines
+ */
+
+extern void putDebugChar();	/* write a single character      */
+extern int getDebugChar();	/* read and return a single char */
+extern void exceptionHandler();	/* assign an exception handler   */
+
+/************************************************************************/
+/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
+/* at least NUMREGBYTES*2 are needed for register packets */
+#define BUFMAX 400
+
+static char initialized;  /* boolean flag. != 0 means we've been initialized */
+
+int     remote_debug;
+/*  debug >  0 prints ill-formed commands in valid packets & checksum errors */
+
+static const char hexchars[]="0123456789abcdef";
+
+/* Number of registers.  */
+#define NUMREGS	16
+
+/* Number of bytes of registers.  */
+#define NUMREGBYTES (NUMREGS * 4)
+
+enum regnames {EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI,
+	       PC /* also known as eip */,
+	       PS /* also known as eflags */,
+	       CS, SS, DS, ES, FS, GS};
+
+/*
+ * these should not be static cuz they can be used outside this module
+ */
+int registers[NUMREGS];
+
+#define STACKSIZE 10000
+int remcomStack[STACKSIZE/sizeof(int)];
+static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1];
+
+/***************************  ASSEMBLY CODE MACROS *************************/
+/* 									   */
+
+extern void
+return_to_prog ();
+
+/* Restore the program's registers (including the stack pointer, which
+   means we get the right stack and don't have to worry about popping our
+   return address and any stack frames and so on) and return.  */
+asm(".text");
+asm(".globl _return_to_prog");
+asm("_return_to_prog:");
+asm("        movw _registers+44, %ss");
+asm("        movl _registers+16, %esp");
+asm("        movl _registers+4, %ecx");
+asm("        movl _registers+8, %edx");
+asm("        movl _registers+12, %ebx");
+asm("        movl _registers+20, %ebp");
+asm("        movl _registers+24, %esi");
+asm("        movl _registers+28, %edi");
+asm("        movw _registers+48, %ds");
+asm("        movw _registers+52, %es");
+asm("        movw _registers+56, %fs");
+asm("        movw _registers+60, %gs");
+asm("        movl _registers+36, %eax");
+asm("        pushl %eax");  /* saved eflags */
+asm("        movl _registers+40, %eax");
+asm("        pushl %eax");  /* saved cs */
+asm("        movl _registers+32, %eax");
+asm("        pushl %eax");  /* saved eip */
+asm("        movl _registers, %eax");
+/* use iret to restore pc and flags together so
+   that trace flag works right.  */
+asm("        iret");
+
+#define BREAKPOINT() asm("   int $3");
+
+/* Put the error code here just in case the user cares.  */
+int gdb_i386errcode;
+/* Likewise, the vector number here (since GDB only gets the signal
+   number through the usual means, and that's not very specific).  */
+int gdb_i386vector = -1;
+
+/* GDB stores segment registers in 32-bit words (that's just the way
+   m-i386v.h is written).  So zero the appropriate areas in registers.  */
+#define SAVE_REGISTERS1() \
+  asm ("movl %eax, _registers");                                   	  \
+  asm ("movl %ecx, _registers+4");			  		     \
+  asm ("movl %edx, _registers+8");			  		     \
+  asm ("movl %ebx, _registers+12");			  		     \
+  asm ("movl %ebp, _registers+20");			  		     \
+  asm ("movl %esi, _registers+24");			  		     \
+  asm ("movl %edi, _registers+28");			  		     \
+  asm ("movw $0, %ax");							     \
+  asm ("movw %ds, _registers+48");			  		     \
+  asm ("movw %ax, _registers+50");					     \
+  asm ("movw %es, _registers+52");			  		     \
+  asm ("movw %ax, _registers+54");					     \
+  asm ("movw %fs, _registers+56");			  		     \
+  asm ("movw %ax, _registers+58");					     \
+  asm ("movw %gs, _registers+60");			  		     \
+  asm ("movw %ax, _registers+62");
+#define SAVE_ERRCODE() \
+  asm ("popl %ebx");                                  \
+  asm ("movl %ebx, _gdb_i386errcode");
+#define SAVE_REGISTERS2() \
+  asm ("popl %ebx"); /* old eip */			  		     \
+  asm ("movl %ebx, _registers+32");			  		     \
+  asm ("popl %ebx");	 /* old cs */			  		     \
+  asm ("movl %ebx, _registers+40");			  		     \
+  asm ("movw %ax, _registers+42");                                           \
+  asm ("popl %ebx");	 /* old eflags */		  		     \
+  asm ("movl %ebx, _registers+36");			 		     \
+  /* Now that we've done the pops, we can save the stack pointer.");  */   \
+  asm ("movw %ss, _registers+44");					     \
+  asm ("movw %ax, _registers+46");     	       	       	       	       	     \
+  asm ("movl %esp, _registers+16");
+
+/* See if mem_fault_routine is set, if so just IRET to that address.  */
+#define CHECK_FAULT() \
+  asm ("cmpl $0, _mem_fault_routine");					   \
+  asm ("jne mem_fault");
+
+asm (".text");
+asm ("mem_fault:");
+/* OK to clobber temp registers; we're just going to end up in set_mem_err.  */
+/* Pop error code from the stack and save it.  */
+asm ("     popl %eax");
+asm ("     movl %eax, _gdb_i386errcode");
+
+asm ("     popl %eax"); /* eip */
+/* We don't want to return there, we want to return to the function
+   pointed to by mem_fault_routine instead.  */
+asm ("     movl _mem_fault_routine, %eax");
+asm ("     popl %ecx"); /* cs (low 16 bits; junk in hi 16 bits).  */
+asm ("     popl %edx"); /* eflags */
+
+/* Remove this stack frame; when we do the iret, we will be going to
+   the start of a function, so we want the stack to look just like it
+   would after a "call" instruction.  */
+asm ("     leave");
+
+/* Push the stuff that iret wants.  */
+asm ("     pushl %edx"); /* eflags */
+asm ("     pushl %ecx"); /* cs */
+asm ("     pushl %eax"); /* eip */
+
+/* Zero mem_fault_routine.  */
+asm ("     movl $0, %eax");
+asm ("     movl %eax, _mem_fault_routine");
+
+asm ("iret");
+
+#define CALL_HOOK() asm("call _remcomHandler");
+
+/* This function is called when a i386 exception occurs.  It saves
+ * all the cpu regs in the _registers array, munges the stack a bit,
+ * and invokes an exception handler (remcom_handler).
+ *
+ * stack on entry:                       stack on exit:
+ *   old eflags                          vector number
+ *   old cs (zero-filled to 32 bits)
+ *   old eip
+ *
+ */
+extern void _catchException3();
+asm(".text");
+asm(".globl __catchException3");
+asm("__catchException3:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $3");
+CALL_HOOK();
+
+/* Same thing for exception 1.  */
+extern void _catchException1();
+asm(".text");
+asm(".globl __catchException1");
+asm("__catchException1:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $1");
+CALL_HOOK();
+
+/* Same thing for exception 0.  */
+extern void _catchException0();
+asm(".text");
+asm(".globl __catchException0");
+asm("__catchException0:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $0");
+CALL_HOOK();
+
+/* Same thing for exception 4.  */
+extern void _catchException4();
+asm(".text");
+asm(".globl __catchException4");
+asm("__catchException4:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $4");
+CALL_HOOK();
+
+/* Same thing for exception 5.  */
+extern void _catchException5();
+asm(".text");
+asm(".globl __catchException5");
+asm("__catchException5:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $5");
+CALL_HOOK();
+
+/* Same thing for exception 6.  */
+extern void _catchException6();
+asm(".text");
+asm(".globl __catchException6");
+asm("__catchException6:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $6");
+CALL_HOOK();
+
+/* Same thing for exception 7.  */
+extern void _catchException7();
+asm(".text");
+asm(".globl __catchException7");
+asm("__catchException7:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $7");
+CALL_HOOK();
+
+/* Same thing for exception 8.  */
+extern void _catchException8();
+asm(".text");
+asm(".globl __catchException8");
+asm("__catchException8:");
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $8");
+CALL_HOOK();
+
+/* Same thing for exception 9.  */
+extern void _catchException9();
+asm(".text");
+asm(".globl __catchException9");
+asm("__catchException9:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $9");
+CALL_HOOK();
+
+/* Same thing for exception 10.  */
+extern void _catchException10();
+asm(".text");
+asm(".globl __catchException10");
+asm("__catchException10:");
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $10");
+CALL_HOOK();
+
+/* Same thing for exception 12.  */
+extern void _catchException12();
+asm(".text");
+asm(".globl __catchException12");
+asm("__catchException12:");
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $12");
+CALL_HOOK();
+
+/* Same thing for exception 16.  */
+extern void _catchException16();
+asm(".text");
+asm(".globl __catchException16");
+asm("__catchException16:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $16");
+CALL_HOOK();
+
+/* For 13, 11, and 14 we have to deal with the CHECK_FAULT stuff.  */
+
+/* Same thing for exception 13.  */
+extern void _catchException13 ();
+asm (".text");
+asm (".globl __catchException13");
+asm ("__catchException13:");
+CHECK_FAULT();
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $13");
+CALL_HOOK();
+
+/* Same thing for exception 11.  */
+extern void _catchException11 ();
+asm (".text");
+asm (".globl __catchException11");
+asm ("__catchException11:");
+CHECK_FAULT();
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $11");
+CALL_HOOK();
+
+/* Same thing for exception 14.  */
+extern void _catchException14 ();
+asm (".text");
+asm (".globl __catchException14");
+asm ("__catchException14:");
+CHECK_FAULT();
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $14");
+CALL_HOOK();
+
+/*
+ * remcomHandler is a front end for handle_exception.  It moves the
+ * stack pointer into an area reserved for debugger use.
+ */
+asm("_remcomHandler:");
+asm("           popl %eax");        /* pop off return address     */
+asm("           popl %eax");      /* get the exception number   */
+asm("		movl _stackPtr, %esp"); /* move to remcom stack area  */
+asm("		pushl %eax");	/* push exception onto stack  */
+asm("		call  _handle_exception");    /* this never returns */
+
+void
+_returnFromException ()
+{
+  return_to_prog ();
+}
+
+int
+hex (ch)
+     char ch;
+{
+  if ((ch >= 'a') && (ch <= 'f'))
+    return (ch - 'a' + 10);
+  if ((ch >= '0') && (ch <= '9'))
+    return (ch - '0');
+  if ((ch >= 'A') && (ch <= 'F'))
+    return (ch - 'A' + 10);
+  return (-1);
+}
+
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
+
+/* scan for the sequence $<data>#<checksum>     */
+
+unsigned char *
+getpacket (void)
+{
+  unsigned char *buffer = &remcomInBuffer[0];
+  unsigned char checksum;
+  unsigned char xmitcsum;
+  int count;
+  char ch;
+
+  while (1)
+    {
+      /* wait around for the start character, ignore all other characters */
+      while ((ch = getDebugChar ()) != '$')
+	;
+
+    retry:
+      checksum = 0;
+      xmitcsum = -1;
+      count = 0;
+
+      /* now, read until a # or end of buffer is found */
+      while (count < BUFMAX - 1)
+	{
+	  ch = getDebugChar ();
+	  if (ch == '$')
+	    goto retry;
+	  if (ch == '#')
+	    break;
+	  checksum = checksum + ch;
+	  buffer[count] = ch;
+	  count = count + 1;
+	}
+      buffer[count] = 0;
+
+      if (ch == '#')
+	{
+	  ch = getDebugChar ();
+	  xmitcsum = hex (ch) << 4;
+	  ch = getDebugChar ();
+	  xmitcsum += hex (ch);
+
+	  if (checksum != xmitcsum)
+	    {
+	      if (remote_debug)
+		{
+		  fprintf (stderr,
+			   "bad checksum.  My count = 0x%x, sent=0x%x. buf=%s\n",
+			   checksum, xmitcsum, buffer);
+		}
+	      putDebugChar ('-');	/* failed checksum */
+	    }
+	  else
+	    {
+	      putDebugChar ('+');	/* successful transfer */
+
+	      /* if a sequence char is present, reply the sequence ID */
+	      if (buffer[2] == ':')
+		{
+		  putDebugChar (buffer[0]);
+		  putDebugChar (buffer[1]);
+
+		  return &buffer[3];
+		}
+
+	      return &buffer[0];
+	    }
+	}
+    }
+}
+
+/* send the packet in buffer.  */
+
+void
+putpacket (unsigned char *buffer)
+{
+  unsigned char checksum;
+  int count;
+  char ch;
+
+  /*  $<packet info>#<checksum>.  */
+  do
+    {
+      putDebugChar ('$');
+      checksum = 0;
+      count = 0;
+
+      while (ch = buffer[count])
+	{
+	  putDebugChar (ch);
+	  checksum += ch;
+	  count += 1;
+	}
+
+      putDebugChar ('#');
+      putDebugChar (hexchars[checksum >> 4]);
+      putDebugChar (hexchars[checksum % 16]);
+
+    }
+  while (getDebugChar () != '+');
+}
+
+void
+debug_error (format, parm)
+     char *format;
+     char *parm;
+{
+  if (remote_debug)
+    fprintf (stderr, format, parm);
+}
+
+/* Address of a routine to RTE to if we get a memory fault.  */
+static void (*volatile mem_fault_routine) () = NULL;
+
+/* Indicate to caller of mem2hex or hex2mem that there has been an
+   error.  */
+static volatile int mem_err = 0;
+
+void
+set_mem_err (void)
+{
+  mem_err = 1;
+}
+
+/* These are separate functions so that they are so short and sweet
+   that the compiler won't save any registers (if there is a fault
+   to mem_fault, they won't get restored, so there better not be any
+   saved).  */
+int
+get_char (char *addr)
+{
+  return *addr;
+}
+
+void
+set_char (char *addr, int val)
+{
+  *addr = val;
+}
+
+/* convert the memory pointed to by mem into hex, placing result in buf */
+/* return a pointer to the last char put in buf (null) */
+/* If MAY_FAULT is non-zero, then we should set mem_err in response to
+   a fault; if zero treat a fault like any other fault in the stub.  */
+char *
+mem2hex (mem, buf, count, may_fault)
+     char *mem;
+     char *buf;
+     int count;
+     int may_fault;
+{
+  int i;
+  unsigned char ch;
+
+  if (may_fault)
+    mem_fault_routine = set_mem_err;
+  for (i = 0; i < count; i++)
+    {
+      ch = get_char (mem++);
+      if (may_fault && mem_err)
+	return (buf);
+      *buf++ = hexchars[ch >> 4];
+      *buf++ = hexchars[ch % 16];
+    }
+  *buf = 0;
+  if (may_fault)
+    mem_fault_routine = NULL;
+  return (buf);
+}
+
+/* convert the hex array pointed to by buf into binary to be placed in mem */
+/* return a pointer to the character AFTER the last byte written */
+char *
+hex2mem (buf, mem, count, may_fault)
+     char *buf;
+     char *mem;
+     int count;
+     int may_fault;
+{
+  int i;
+  unsigned char ch;
+
+  if (may_fault)
+    mem_fault_routine = set_mem_err;
+  for (i = 0; i < count; i++)
+    {
+      ch = hex (*buf++) << 4;
+      ch = ch + hex (*buf++);
+      set_char (mem++, ch);
+      if (may_fault && mem_err)
+	return (mem);
+    }
+  if (may_fault)
+    mem_fault_routine = NULL;
+  return (mem);
+}
+
+/* this function takes the 386 exception vector and attempts to
+   translate this number into a unix compatible signal value */
+int
+computeSignal (int exceptionVector)
+{
+  int sigval;
+  switch (exceptionVector)
+    {
+    case 0:
+      sigval = 8;
+      break;			/* divide by zero */
+    case 1:
+      sigval = 5;
+      break;			/* debug exception */
+    case 3:
+      sigval = 5;
+      break;			/* breakpoint */
+    case 4:
+      sigval = 16;
+      break;			/* into instruction (overflow) */
+    case 5:
+      sigval = 16;
+      break;			/* bound instruction */
+    case 6:
+      sigval = 4;
+      break;			/* Invalid opcode */
+    case 7:
+      sigval = 8;
+      break;			/* coprocessor not available */
+    case 8:
+      sigval = 7;
+      break;			/* double fault */
+    case 9:
+      sigval = 11;
+      break;			/* coprocessor segment overrun */
+    case 10:
+      sigval = 11;
+      break;			/* Invalid TSS */
+    case 11:
+      sigval = 11;
+      break;			/* Segment not present */
+    case 12:
+      sigval = 11;
+      break;			/* stack exception */
+    case 13:
+      sigval = 11;
+      break;			/* general protection */
+    case 14:
+      sigval = 11;
+      break;			/* page fault */
+    case 16:
+      sigval = 7;
+      break;			/* coprocessor error */
+    default:
+      sigval = 7;		/* "software generated" */
+    }
+  return (sigval);
+}
+
+/**********************************************/
+/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */
+/* RETURN NUMBER OF CHARS PROCESSED           */
+/**********************************************/
+int
+hexToInt (char **ptr, int *intValue)
+{
+  int numChars = 0;
+  int hexValue;
+
+  *intValue = 0;
+
+  while (**ptr)
+    {
+      hexValue = hex (**ptr);
+      if (hexValue >= 0)
+	{
+	  *intValue = (*intValue << 4) | hexValue;
+	  numChars++;
+	}
+      else
+	break;
+
+      (*ptr)++;
+    }
+
+  return (numChars);
+}
+
+/*
+ * This function does all command procesing for interfacing to gdb.
+ */
+void
+handle_exception (int exceptionVector)
+{
+  int sigval, stepping;
+  int addr, length;
+  char *ptr;
+  int newPC;
+
+  gdb_i386vector = exceptionVector;
+
+  if (remote_debug)
+    {
+      printf ("vector=%d, sr=0x%x, pc=0x%x\n",
+	      exceptionVector, registers[PS], registers[PC]);
+    }
+
+  /* reply to host that an exception has occurred */
+  sigval = computeSignal (exceptionVector);
+
+  ptr = remcomOutBuffer;
+
+  *ptr++ = 'T';			/* notify gdb with signo, PC, FP and SP */
+  *ptr++ = hexchars[sigval >> 4];
+  *ptr++ = hexchars[sigval & 0xf];
+
+  *ptr++ = hexchars[ESP]; 
+  *ptr++ = ':';
+  ptr = mem2hex((char *)&registers[ESP], ptr, 4, 0);	/* SP */
+  *ptr++ = ';';
+
+  *ptr++ = hexchars[EBP]; 
+  *ptr++ = ':';
+  ptr = mem2hex((char *)&registers[EBP], ptr, 4, 0); 	/* FP */
+  *ptr++ = ';';
+
+  *ptr++ = hexchars[PC]; 
+  *ptr++ = ':';
+  ptr = mem2hex((char *)&registers[PC], ptr, 4, 0); 	/* PC */
+  *ptr++ = ';';
+
+  *ptr = '\0'
+
+  putpacket (remcomOutBuffer);
+
+  stepping = 0;
+
+  while (1 == 1)
+    {
+      remcomOutBuffer[0] = 0;
+      ptr = getpacket ();
+
+      switch (*ptr++)
+	{
+	case '?':
+	  remcomOutBuffer[0] = 'S';
+	  remcomOutBuffer[1] = hexchars[sigval >> 4];
+	  remcomOutBuffer[2] = hexchars[sigval % 16];
+	  remcomOutBuffer[3] = 0;
+	  break;
+	case 'd':
+	  remote_debug = !(remote_debug);	/* toggle debug flag */
+	  break;
+	case 'g':		/* return the value of the CPU registers */
+	  mem2hex ((char *) registers, remcomOutBuffer, NUMREGBYTES, 0);
+	  break;
+	case 'G':		/* set the value of the CPU registers - return OK */
+	  hex2mem (ptr, (char *) registers, NUMREGBYTES, 0);
+	  strcpy (remcomOutBuffer, "OK");
+	  break;
+	case 'P':		/* set the value of a single CPU register - return OK */
+	  {
+	    int regno;
+
+	    if (hexToInt (&ptr, &regno) && *ptr++ == '=')
+	      if (regno >= 0 && regno < NUMREGS)
+		{
+		  hex2mem (ptr, (char *) &registers[regno], 4, 0);
+		  strcpy (remcomOutBuffer, "OK");
+		  break;
+		}
+
+	    strcpy (remcomOutBuffer, "E01");
+	    break;
+	  }
+
+	  /* mAA..AA,LLLL  Read LLLL bytes at address AA..AA */
+	case 'm':
+	  /* TRY TO READ %x,%x.  IF SUCCEED, SET PTR = 0 */
+	  if (hexToInt (&ptr, &addr))
+	    if (*(ptr++) == ',')
+	      if (hexToInt (&ptr, &length))
+		{
+		  ptr = 0;
+		  mem_err = 0;
+		  mem2hex ((char *) addr, remcomOutBuffer, length, 1);
+		  if (mem_err)
+		    {
+		      strcpy (remcomOutBuffer, "E03");
+		      debug_error ("memory fault");
+		    }
+		}
+
+	  if (ptr)
+	    {
+	      strcpy (remcomOutBuffer, "E01");
+	    }
+	  break;
+
+	  /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
+	case 'M':
+	  /* TRY TO READ '%x,%x:'.  IF SUCCEED, SET PTR = 0 */
+	  if (hexToInt (&ptr, &addr))
+	    if (*(ptr++) == ',')
+	      if (hexToInt (&ptr, &length))
+		if (*(ptr++) == ':')
+		  {
+		    mem_err = 0;
+		    hex2mem (ptr, (char *) addr, length, 1);
+
+		    if (mem_err)
+		      {
+			strcpy (remcomOutBuffer, "E03");
+			debug_error ("memory fault");
+		      }
+		    else
+		      {
+			strcpy (remcomOutBuffer, "OK");
+		      }
+
+		    ptr = 0;
+		  }
+	  if (ptr)
+	    {
+	      strcpy (remcomOutBuffer, "E02");
+	    }
+	  break;
+
+	  /* cAA..AA    Continue at address AA..AA(optional) */
+	  /* sAA..AA   Step one instruction from AA..AA(optional) */
+	case 's':
+	  stepping = 1;
+	case 'c':
+	  /* try to read optional parameter, pc unchanged if no parm */
+	  if (hexToInt (&ptr, &addr))
+	    registers[PC] = addr;
+
+	  newPC = registers[PC];
+
+	  /* clear the trace bit */
+	  registers[PS] &= 0xfffffeff;
+
+	  /* set the trace bit if we're stepping */
+	  if (stepping)
+	    registers[PS] |= 0x100;
+
+	  _returnFromException ();	/* this is a jump */
+	  break;
+
+	  /* kill the program */
+	case 'k':		/* do nothing */
+#if 0
+	  /* Huh? This doesn't look like "nothing".
+	     m68k-stub.c and sparc-stub.c don't have it.  */
+	  BREAKPOINT ();
+#endif
+	  break;
+	}			/* switch */
+
+      /* reply to the request */
+      putpacket (remcomOutBuffer);
+    }
+}
+
+/* this function is used to set up exception handlers for tracing and
+   breakpoints */
+void
+set_debug_traps (void)
+{
+  stackPtr = &remcomStack[STACKSIZE / sizeof (int) - 1];
+
+  exceptionHandler (0, _catchException0);
+  exceptionHandler (1, _catchException1);
+  exceptionHandler (3, _catchException3);
+  exceptionHandler (4, _catchException4);
+  exceptionHandler (5, _catchException5);
+  exceptionHandler (6, _catchException6);
+  exceptionHandler (7, _catchException7);
+  exceptionHandler (8, _catchException8);
+  exceptionHandler (9, _catchException9);
+  exceptionHandler (10, _catchException10);
+  exceptionHandler (11, _catchException11);
+  exceptionHandler (12, _catchException12);
+  exceptionHandler (13, _catchException13);
+  exceptionHandler (14, _catchException14);
+  exceptionHandler (16, _catchException16);
+
+  initialized = 1;
+}
+
+/* This function will generate a breakpoint exception.  It is used at the
+   beginning of a program to sync up with a debugger and can be used
+   otherwise as a quick means to stop program execution and "break" into
+   the debugger.  */
+
+void
+breakpoint (void)
+{
+  if (initialized)
+    BREAKPOINT ();
+}
diff --git a/gdb/stubs/m32r-stub.c b/gdb/stubs/m32r-stub.c
new file mode 100644
index 00000000000..4d54f72d60b
--- /dev/null
+++ b/gdb/stubs/m32r-stub.c
@@ -0,0 +1,1779 @@
+/****************************************************************************
+
+		THIS SOFTWARE IS NOT COPYRIGHTED
+
+   HP offers the following for use in the public domain.  HP makes no
+   warranty with regard to the software or it's performance and the
+   user accepts the software "AS IS" with all faults.
+
+   HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
+   TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+
+****************************************************************************/
+
+/****************************************************************************
+ *  Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
+ *
+ *  Module name: remcom.c $
+ *  Revision: 1.34 $
+ *  Date: 91/03/09 12:29:49 $
+ *  Contributor:     Lake Stevens Instrument Division$
+ *
+ *  Description:     low level support for gdb debugger. $
+ *
+ *  Considerations:  only works on target hardware $
+ *
+ *  Written by:      Glenn Engel $
+ *  ModuleState:     Experimental $
+ *
+ *  NOTES:           See Below $
+ *
+ *  Modified for M32R by Michael Snyder, Cygnus Support.
+ *
+ *  To enable debugger support, two things need to happen.  One, a
+ *  call to set_debug_traps() is necessary in order to allow any breakpoints
+ *  or error conditions to be properly intercepted and reported to gdb.
+ *  Two, a breakpoint needs to be generated to begin communication.  This
+ *  is most easily accomplished by a call to breakpoint().  Breakpoint()
+ *  simulates a breakpoint by executing a trap #1.
+ *
+ *  The external function exceptionHandler() is
+ *  used to attach a specific handler to a specific M32R vector number.
+ *  It should use the same privilege level it runs at.  It should
+ *  install it as an interrupt gate so that interrupts are masked
+ *  while the handler runs.
+ *
+ *  Because gdb will sometimes write to the stack area to execute function
+ *  calls, this program cannot rely on using the supervisor stack so it
+ *  uses it's own stack area reserved in the int array remcomStack.
+ *
+ *************
+ *
+ *    The following gdb commands are supported:
+ *
+ * command          function                               Return value
+ *
+ *    g             return the value of the CPU registers  hex data or ENN
+ *    G             set the value of the CPU registers     OK or ENN
+ *
+ *    mAA..AA,LLLL  Read LLLL bytes at address AA..AA      hex data or ENN
+ *    MAA..AA,LLLL: Write LLLL bytes at address AA.AA      OK or ENN
+ *    XAA..AA,LLLL: Write LLLL binary bytes at address     OK or ENN
+ *                  AA..AA
+ *
+ *    c             Resume at current address              SNN   ( signal NN)
+ *    cAA..AA       Continue at address AA..AA             SNN
+ *
+ *    s             Step one instruction                   SNN
+ *    sAA..AA       Step one instruction from AA..AA       SNN
+ *
+ *    k             kill
+ *
+ *    ?             What was the last sigval ?             SNN   (signal NN)
+ *
+ * All commands and responses are sent with a packet which includes a
+ * checksum.  A packet consists of
+ *
+ * $<packet info>#<checksum>.
+ *
+ * where
+ * <packet info> :: <characters representing the command or response>
+ * <checksum>    :: <two hex digits computed as modulo 256 sum of <packetinfo>>
+ *
+ * When a packet is received, it is first acknowledged with either '+' or '-'.
+ * '+' indicates a successful transfer.  '-' indicates a failed transfer.
+ *
+ * Example:
+ *
+ * Host:                  Reply:
+ * $m0,10#2a               +$00010203040506070809101112131415#42
+ *
+ ****************************************************************************/
+
+
+/************************************************************************
+ *
+ * external low-level support routines
+ */
+extern void putDebugChar ();	/* write a single character      */
+extern int getDebugChar ();	/* read and return a single char */
+extern void exceptionHandler ();	/* assign an exception handler   */
+
+/*****************************************************************************
+ * BUFMAX defines the maximum number of characters in inbound/outbound buffers
+ * at least NUMREGBYTES*2 are needed for register packets 
+ */
+#define BUFMAX 400
+
+static char initialized;	/* boolean flag. != 0 means we've been initialized */
+
+int remote_debug;
+/*  debug >  0 prints ill-formed commands in valid packets & checksum errors */
+
+static const unsigned char hexchars[] = "0123456789abcdef";
+
+#define NUMREGS 24
+
+/* Number of bytes of registers.  */
+#define NUMREGBYTES (NUMREGS * 4)
+enum regnames
+{ R0, R1, R2, R3, R4, R5, R6, R7,
+  R8, R9, R10, R11, R12, R13, R14, R15,
+  PSW, CBR, SPI, SPU, BPC, PC, ACCL, ACCH
+};
+
+enum SYS_calls
+{
+  SYS_null,
+  SYS_exit,
+  SYS_open,
+  SYS_close,
+  SYS_read,
+  SYS_write,
+  SYS_lseek,
+  SYS_unlink,
+  SYS_getpid,
+  SYS_kill,
+  SYS_fstat,
+  SYS_sbrk,
+  SYS_fork,
+  SYS_execve,
+  SYS_wait4,
+  SYS_link,
+  SYS_chdir,
+  SYS_stat,
+  SYS_utime,
+  SYS_chown,
+  SYS_chmod,
+  SYS_time,
+  SYS_pipe
+};
+
+static int registers[NUMREGS];
+
+#define STACKSIZE 8096
+static unsigned char remcomInBuffer[BUFMAX];
+static unsigned char remcomOutBuffer[BUFMAX];
+static int remcomStack[STACKSIZE / sizeof (int)];
+static int *stackPtr = &remcomStack[STACKSIZE / sizeof (int) - 1];
+
+static unsigned int save_vectors[18];	/* previous exception vectors */
+
+/* Indicate to caller of mem2hex or hex2mem that there has been an error. */
+static volatile int mem_err = 0;
+
+/* Store the vector number here (since GDB only gets the signal
+   number through the usual means, and that's not very specific).  */
+int gdb_m32r_vector = -1;
+
+#if 0
+#include "syscall.h"		/* for SYS_exit, SYS_write etc. */
+#endif
+
+/* Global entry points:
+ */
+
+extern void handle_exception (int);
+extern void set_debug_traps (void);
+extern void breakpoint (void);
+
+/* Local functions:
+ */
+
+static int computeSignal (int);
+static void putpacket (unsigned char *);
+static unsigned char *getpacket (void);
+
+static unsigned char *mem2hex (unsigned char *, unsigned char *, int, int);
+static unsigned char *hex2mem (unsigned char *, unsigned char *, int, int);
+static int hexToInt (unsigned char **, int *);
+static unsigned char *bin2mem (unsigned char *, unsigned char *, int, int);
+static void stash_registers (void);
+static void restore_registers (void);
+static int prepare_to_step (int);
+static int finish_from_step (void);
+static unsigned long crc32 (unsigned char *, int, unsigned long);
+
+static void gdb_error (char *, char *);
+static int gdb_putchar (int), gdb_puts (char *), gdb_write (char *, int);
+
+static unsigned char *strcpy (unsigned char *, const unsigned char *);
+static int strlen (const unsigned char *);
+
+/*
+ * This function does all command procesing for interfacing to gdb.
+ */
+
+void
+handle_exception (int exceptionVector)
+{
+  int sigval, stepping;
+  int addr, length, i;
+  unsigned char *ptr;
+  unsigned char buf[16];
+  int binary;
+
+  if (!finish_from_step ())
+    return;			/* "false step": let the target continue */
+
+  gdb_m32r_vector = exceptionVector;
+
+  if (remote_debug)
+    {
+      mem2hex ((unsigned char *) &exceptionVector, buf, 4, 0);
+      gdb_error ("Handle exception %s, ", buf);
+      mem2hex ((unsigned char *) &registers[PC], buf, 4, 0);
+      gdb_error ("PC == 0x%s\n", buf);
+    }
+
+  /* reply to host that an exception has occurred */
+  sigval = computeSignal (exceptionVector);
+
+  ptr = remcomOutBuffer;
+
+  *ptr++ = 'T';			/* notify gdb with signo, PC, FP and SP */
+  *ptr++ = hexchars[sigval >> 4];
+  *ptr++ = hexchars[sigval & 0xf];
+
+  *ptr++ = hexchars[PC >> 4];
+  *ptr++ = hexchars[PC & 0xf];
+  *ptr++ = ':';
+  ptr = mem2hex ((unsigned char *) &registers[PC], ptr, 4, 0);	/* PC */
+  *ptr++ = ';';
+
+  *ptr++ = hexchars[R13 >> 4];
+  *ptr++ = hexchars[R13 & 0xf];
+  *ptr++ = ':';
+  ptr = mem2hex ((unsigned char *) &registers[R13], ptr, 4, 0);	/* FP */
+  *ptr++ = ';';
+
+  *ptr++ = hexchars[R15 >> 4];
+  *ptr++ = hexchars[R15 & 0xf];
+  *ptr++ = ':';
+  ptr = mem2hex ((unsigned char *) &registers[R15], ptr, 4, 0);	/* SP */
+  *ptr++ = ';';
+  *ptr++ = 0;
+
+  if (exceptionVector == 0)	/* simulated SYS call stuff */
+    {
+      mem2hex ((unsigned char *) &registers[PC], buf, 4, 0);
+      switch (registers[R0])
+	{
+	case SYS_exit:
+	  gdb_error ("Target program has exited at %s\n", buf);
+	  ptr = remcomOutBuffer;
+	  *ptr++ = 'W';
+	  sigval = registers[R1] & 0xff;
+	  *ptr++ = hexchars[sigval >> 4];
+	  *ptr++ = hexchars[sigval & 0xf];
+	  *ptr++ = 0;
+	  break;
+	case SYS_open:
+	  gdb_error ("Target attempts SYS_open call at %s\n", buf);
+	  break;
+	case SYS_close:
+	  gdb_error ("Target attempts SYS_close call at %s\n", buf);
+	  break;
+	case SYS_read:
+	  gdb_error ("Target attempts SYS_read call at %s\n", buf);
+	  break;
+	case SYS_write:
+	  if (registers[R1] == 1 ||	/* write to stdout  */
+	      registers[R1] == 2)	/* write to stderr  */
+	    {			/* (we can do that) */
+	      registers[R0] =
+		gdb_write ((void *) registers[R2], registers[R3]);
+	      return;
+	    }
+	  else
+	    gdb_error ("Target attempts SYS_write call at %s\n", buf);
+	  break;
+	case SYS_lseek:
+	  gdb_error ("Target attempts SYS_lseek call at %s\n", buf);
+	  break;
+	case SYS_unlink:
+	  gdb_error ("Target attempts SYS_unlink call at %s\n", buf);
+	  break;
+	case SYS_getpid:
+	  gdb_error ("Target attempts SYS_getpid call at %s\n", buf);
+	  break;
+	case SYS_kill:
+	  gdb_error ("Target attempts SYS_kill call at %s\n", buf);
+	  break;
+	case SYS_fstat:
+	  gdb_error ("Target attempts SYS_fstat call at %s\n", buf);
+	  break;
+	default:
+	  gdb_error ("Target attempts unknown SYS call at %s\n", buf);
+	  break;
+	}
+    }
+
+  putpacket (remcomOutBuffer);
+
+  stepping = 0;
+
+  while (1 == 1)
+    {
+      remcomOutBuffer[0] = 0;
+      ptr = getpacket ();
+      binary = 0;
+      switch (*ptr++)
+	{
+	default:		/* Unknown code.  Return an empty reply message. */
+	  break;
+	case 'R':
+	  if (hexToInt (&ptr, &addr))
+	    registers[PC] = addr;
+	  strcpy (remcomOutBuffer, "OK");
+	  break;
+	case '!':
+	  strcpy (remcomOutBuffer, "OK");
+	  break;
+	case 'X':		/* XAA..AA,LLLL:<binary data>#cs */
+	  binary = 1;
+	case 'M':		/* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
+	  /* TRY TO READ '%x,%x:'.  IF SUCCEED, SET PTR = 0 */
+	  {
+	    if (hexToInt (&ptr, &addr))
+	      if (*(ptr++) == ',')
+		if (hexToInt (&ptr, &length))
+		  if (*(ptr++) == ':')
+		    {
+		      mem_err = 0;
+		      if (binary)
+			bin2mem (ptr, (unsigned char *) addr, length, 1);
+		      else
+			hex2mem (ptr, (unsigned char *) addr, length, 1);
+		      if (mem_err)
+			{
+			  strcpy (remcomOutBuffer, "E03");
+			  gdb_error ("memory fault", "");
+			}
+		      else
+			{
+			  strcpy (remcomOutBuffer, "OK");
+			}
+		      ptr = 0;
+		    }
+	    if (ptr)
+	      {
+		strcpy (remcomOutBuffer, "E02");
+	      }
+	  }
+	  break;
+	case 'm':		/* mAA..AA,LLLL  Read LLLL bytes at address AA..AA */
+	  /* TRY TO READ %x,%x.  IF SUCCEED, SET PTR = 0 */
+	  if (hexToInt (&ptr, &addr))
+	    if (*(ptr++) == ',')
+	      if (hexToInt (&ptr, &length))
+		{
+		  ptr = 0;
+		  mem_err = 0;
+		  mem2hex ((unsigned char *) addr, remcomOutBuffer, length,
+			   1);
+		  if (mem_err)
+		    {
+		      strcpy (remcomOutBuffer, "E03");
+		      gdb_error ("memory fault", "");
+		    }
+		}
+	  if (ptr)
+	    {
+	      strcpy (remcomOutBuffer, "E01");
+	    }
+	  break;
+	case '?':
+	  remcomOutBuffer[0] = 'S';
+	  remcomOutBuffer[1] = hexchars[sigval >> 4];
+	  remcomOutBuffer[2] = hexchars[sigval % 16];
+	  remcomOutBuffer[3] = 0;
+	  break;
+	case 'd':
+	  remote_debug = !(remote_debug);	/* toggle debug flag */
+	  break;
+	case 'g':		/* return the value of the CPU registers */
+	  mem2hex ((unsigned char *) registers, remcomOutBuffer, NUMREGBYTES,
+		   0);
+	  break;
+	case 'P':		/* set the value of a single CPU register - return OK */
+	  {
+	    int regno;
+
+	    if (hexToInt (&ptr, &regno) && *ptr++ == '=')
+	      if (regno >= 0 && regno < NUMREGS)
+		{
+		  int stackmode;
+
+		  hex2mem (ptr, (unsigned char *) &registers[regno], 4, 0);
+		  /*
+		   * Since we just changed a single CPU register, let's
+		   * make sure to keep the several stack pointers consistant.
+		   */
+		  stackmode = registers[PSW] & 0x80;
+		  if (regno == R15)	/* stack pointer changed */
+		    {		/* need to change SPI or SPU */
+		      if (stackmode == 0)
+			registers[SPI] = registers[R15];
+		      else
+			registers[SPU] = registers[R15];
+		    }
+		  else if (regno == SPU)	/* "user" stack pointer changed */
+		    {
+		      if (stackmode != 0)	/* stack in user mode: copy SP */
+			registers[R15] = registers[SPU];
+		    }
+		  else if (regno == SPI)	/* "interrupt" stack pointer changed */
+		    {
+		      if (stackmode == 0)	/* stack in interrupt mode: copy SP */
+			registers[R15] = registers[SPI];
+		    }
+		  else if (regno == PSW)	/* stack mode may have changed! */
+		    {		/* force SP to either SPU or SPI */
+		      if (stackmode == 0)	/* stack in user mode */
+			registers[R15] = registers[SPI];
+		      else	/* stack in interrupt mode */
+			registers[R15] = registers[SPU];
+		    }
+		  strcpy (remcomOutBuffer, "OK");
+		  break;
+		}
+	    strcpy (remcomOutBuffer, "E01");
+	    break;
+	  }
+	case 'G':		/* set the value of the CPU registers - return OK */
+	  hex2mem (ptr, (unsigned char *) registers, NUMREGBYTES, 0);
+	  strcpy (remcomOutBuffer, "OK");
+	  break;
+	case 's':		/* sAA..AA      Step one instruction from AA..AA(optional) */
+	  stepping = 1;
+	case 'c':		/* cAA..AA      Continue from address AA..AA(optional) */
+	  /* try to read optional parameter, pc unchanged if no parm */
+	  if (hexToInt (&ptr, &addr))
+	    registers[PC] = addr;
+
+	  if (stepping)		/* single-stepping */
+	    {
+	      if (!prepare_to_step (0))	/* set up for single-step */
+		{
+		  /* prepare_to_step has already emulated the target insn:
+		     Send SIGTRAP to gdb, don't resume the target at all.  */
+		  ptr = remcomOutBuffer;
+		  *ptr++ = 'T';	/* Simulate stopping with SIGTRAP */
+		  *ptr++ = '0';
+		  *ptr++ = '5';
+
+		  *ptr++ = hexchars[PC >> 4];	/* send PC */
+		  *ptr++ = hexchars[PC & 0xf];
+		  *ptr++ = ':';
+		  ptr = mem2hex ((unsigned char *) &registers[PC], ptr, 4, 0);
+		  *ptr++ = ';';
+
+		  *ptr++ = hexchars[R13 >> 4];	/* send FP */
+		  *ptr++ = hexchars[R13 & 0xf];
+		  *ptr++ = ':';
+		  ptr =
+		    mem2hex ((unsigned char *) &registers[R13], ptr, 4, 0);
+		  *ptr++ = ';';
+
+		  *ptr++ = hexchars[R15 >> 4];	/* send SP */
+		  *ptr++ = hexchars[R15 & 0xf];
+		  *ptr++ = ':';
+		  ptr =
+		    mem2hex ((unsigned char *) &registers[R15], ptr, 4, 0);
+		  *ptr++ = ';';
+		  *ptr++ = 0;
+
+		  break;
+		}
+	    }
+	  else			/* continuing, not single-stepping */
+	    {
+	      /* OK, about to do a "continue".  First check to see if the 
+	         target pc is on an odd boundary (second instruction in the 
+	         word).  If so, we must do a single-step first, because 
+	         ya can't jump or return back to an odd boundary!  */
+	      if ((registers[PC] & 2) != 0)
+		prepare_to_step (1);
+	    }
+
+	  return;
+
+	case 'D':		/* Detach */
+#if 0
+	  /* I am interpreting this to mean, release the board from control 
+	     by the remote stub.  To do this, I am restoring the original
+	     (or at least previous) exception vectors.
+	   */
+	  for (i = 0; i < 18; i++)
+	    exceptionHandler (i, save_vectors[i]);
+	  putpacket ("OK");
+	  return;		/* continue the inferior */
+#else
+	  strcpy (remcomOutBuffer, "OK");
+	  break;
+#endif
+	case 'q':
+	  if (*ptr++ == 'C' &&
+	      *ptr++ == 'R' && *ptr++ == 'C' && *ptr++ == ':')
+	    {
+	      unsigned long start, len, our_crc;
+
+	      if (hexToInt (&ptr, (int *) &start) &&
+		  *ptr++ == ',' && hexToInt (&ptr, (int *) &len))
+		{
+		  remcomOutBuffer[0] = 'C';
+		  our_crc = crc32 ((unsigned char *) start, len, 0xffffffff);
+		  mem2hex ((char *) &our_crc,
+			   &remcomOutBuffer[1], sizeof (long), 0);
+		}		/* else do nothing */
+	    }			/* else do nothing */
+	  break;
+
+	case 'k':		/* kill the program */
+	  continue;
+	}			/* switch */
+
+      /* reply to the request */
+      putpacket (remcomOutBuffer);
+    }
+}
+
+/* qCRC support */
+
+/* Table used by the crc32 function to calcuate the checksum. */
+static unsigned long crc32_table[256] = { 0, 0 };
+
+static unsigned long
+crc32 (unsigned char *buf, int len, unsigned long crc)
+{
+  if (!crc32_table[1])
+    {
+      /* Initialize the CRC table and the decoding table. */
+      int i, j;
+      unsigned long c;
+
+      for (i = 0; i < 256; i++)
+	{
+	  for (c = i << 24, j = 8; j > 0; --j)
+	    c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1);
+	  crc32_table[i] = c;
+	}
+    }
+
+  while (len--)
+    {
+      crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *buf) & 255];
+      buf++;
+    }
+  return crc;
+}
+
+static int
+hex (unsigned char ch)
+{
+  if ((ch >= 'a') && (ch <= 'f'))
+    return (ch - 'a' + 10);
+  if ((ch >= '0') && (ch <= '9'))
+    return (ch - '0');
+  if ((ch >= 'A') && (ch <= 'F'))
+    return (ch - 'A' + 10);
+  return (-1);
+}
+
+/* scan for the sequence $<data>#<checksum>     */
+
+unsigned char *
+getpacket (void)
+{
+  unsigned char *buffer = &remcomInBuffer[0];
+  unsigned char checksum;
+  unsigned char xmitcsum;
+  int count;
+  char ch;
+
+  while (1)
+    {
+      /* wait around for the start character, ignore all other characters */
+      while ((ch = getDebugChar ()) != '$')
+	;
+
+    retry:
+      checksum = 0;
+      xmitcsum = -1;
+      count = 0;
+
+      /* now, read until a # or end of buffer is found */
+      while (count < BUFMAX - 1)
+	{
+	  ch = getDebugChar ();
+	  if (ch == '$')
+	    goto retry;
+	  if (ch == '#')
+	    break;
+	  checksum = checksum + ch;
+	  buffer[count] = ch;
+	  count = count + 1;
+	}
+      buffer[count] = 0;
+
+      if (ch == '#')
+	{
+	  ch = getDebugChar ();
+	  xmitcsum = hex (ch) << 4;
+	  ch = getDebugChar ();
+	  xmitcsum += hex (ch);
+
+	  if (checksum != xmitcsum)
+	    {
+	      if (remote_debug)
+		{
+		  unsigned char buf[16];
+
+		  mem2hex ((unsigned char *) &checksum, buf, 4, 0);
+		  gdb_error ("Bad checksum: my count = %s, ", buf);
+		  mem2hex ((unsigned char *) &xmitcsum, buf, 4, 0);
+		  gdb_error ("sent count = %s\n", buf);
+		  gdb_error (" -- Bad buffer: \"%s\"\n", buffer);
+		}
+	      putDebugChar ('-');	/* failed checksum */
+	    }
+	  else
+	    {
+	      putDebugChar ('+');	/* successful transfer */
+
+	      /* if a sequence char is present, reply the sequence ID */
+	      if (buffer[2] == ':')
+		{
+		  putDebugChar (buffer[0]);
+		  putDebugChar (buffer[1]);
+
+		  return &buffer[3];
+		}
+
+	      return &buffer[0];
+	    }
+	}
+    }
+}
+
+/* send the packet in buffer.  */
+
+static void
+putpacket (unsigned char *buffer)
+{
+  unsigned char checksum;
+  int count;
+  char ch;
+
+  /*  $<packet info>#<checksum>. */
+  do
+    {
+      putDebugChar ('$');
+      checksum = 0;
+      count = 0;
+
+      while (ch = buffer[count])
+	{
+	  putDebugChar (ch);
+	  checksum += ch;
+	  count += 1;
+	}
+      putDebugChar ('#');
+      putDebugChar (hexchars[checksum >> 4]);
+      putDebugChar (hexchars[checksum % 16]);
+    }
+  while (getDebugChar () != '+');
+}
+
+/* Address of a routine to RTE to if we get a memory fault.  */
+
+static void (*volatile mem_fault_routine) () = 0;
+
+static void
+set_mem_err (void)
+{
+  mem_err = 1;
+}
+
+/* Check the address for safe access ranges.  As currently defined,
+   this routine will reject the "expansion bus" address range(s).
+   To make those ranges useable, someone must implement code to detect
+   whether there's anything connected to the expansion bus. */
+
+static int
+mem_safe (unsigned char *addr)
+{
+#define BAD_RANGE_ONE_START	((unsigned char *) 0x600000)
+#define BAD_RANGE_ONE_END	((unsigned char *) 0xa00000)
+#define BAD_RANGE_TWO_START	((unsigned char *) 0xff680000)
+#define BAD_RANGE_TWO_END	((unsigned char *) 0xff800000)
+
+  if (addr < BAD_RANGE_ONE_START)
+    return 1;			/* safe */
+  if (addr < BAD_RANGE_ONE_END)
+    return 0;			/* unsafe */
+  if (addr < BAD_RANGE_TWO_START)
+    return 1;			/* safe */
+  if (addr < BAD_RANGE_TWO_END)
+    return 0;			/* unsafe */
+}
+
+/* These are separate functions so that they are so short and sweet
+   that the compiler won't save any registers (if there is a fault
+   to mem_fault, they won't get restored, so there better not be any
+   saved).  */
+static int
+get_char (unsigned char *addr)
+{
+#if 1
+  if (mem_fault_routine && !mem_safe (addr))
+    {
+      mem_fault_routine ();
+      return 0;
+    }
+#endif
+  return *addr;
+}
+
+static void
+set_char (unsigned char *addr, unsigned char val)
+{
+#if 1
+  if (mem_fault_routine && !mem_safe (addr))
+    {
+      mem_fault_routine ();
+      return;
+    }
+#endif
+  *addr = val;
+}
+
+/* Convert the memory pointed to by mem into hex, placing result in buf.
+   Return a pointer to the last char put in buf (null).
+   If MAY_FAULT is non-zero, then we should set mem_err in response to
+   a fault; if zero treat a fault like any other fault in the stub.  */
+
+static unsigned char *
+mem2hex (unsigned char *mem, unsigned char *buf, int count, int may_fault)
+{
+  int i;
+  unsigned char ch;
+
+  if (may_fault)
+    mem_fault_routine = set_mem_err;
+  for (i = 0; i < count; i++)
+    {
+      ch = get_char (mem++);
+      if (may_fault && mem_err)
+	return (buf);
+      *buf++ = hexchars[ch >> 4];
+      *buf++ = hexchars[ch % 16];
+    }
+  *buf = 0;
+  if (may_fault)
+    mem_fault_routine = 0;
+  return (buf);
+}
+
+/* Convert the hex array pointed to by buf into binary to be placed in mem.
+   Return a pointer to the character AFTER the last byte written. */
+
+static unsigned char *
+hex2mem (unsigned char *buf, unsigned char *mem, int count, int may_fault)
+{
+  int i;
+  unsigned char ch;
+
+  if (may_fault)
+    mem_fault_routine = set_mem_err;
+  for (i = 0; i < count; i++)
+    {
+      ch = hex (*buf++) << 4;
+      ch = ch + hex (*buf++);
+      set_char (mem++, ch);
+      if (may_fault && mem_err)
+	return (mem);
+    }
+  if (may_fault)
+    mem_fault_routine = 0;
+  return (mem);
+}
+
+/* Convert the binary stream in BUF to memory.
+
+   Gdb will escape $, #, and the escape char (0x7d).
+   COUNT is the total number of bytes to write into
+   memory. */
+static unsigned char *
+bin2mem (unsigned char *buf, unsigned char *mem, int count, int may_fault)
+{
+  int i;
+  unsigned char ch;
+
+  if (may_fault)
+    mem_fault_routine = set_mem_err;
+  for (i = 0; i < count; i++)
+    {
+      /* Check for any escaped characters. Be paranoid and
+         only unescape chars that should be escaped. */
+      if (*buf == 0x7d)
+	{
+	  switch (*(buf + 1))
+	    {
+	    case 0x3:		/* # */
+	    case 0x4:		/* $ */
+	    case 0x5d:		/* escape char */
+	      buf++;
+	      *buf |= 0x20;
+	      break;
+	    default:
+	      /* nothing */
+	      break;
+	    }
+	}
+
+      set_char (mem++, *buf++);
+
+      if (may_fault && mem_err)
+	return mem;
+    }
+
+  if (may_fault)
+    mem_fault_routine = 0;
+  return mem;
+}
+
+/* this function takes the m32r exception vector and attempts to
+   translate this number into a unix compatible signal value */
+
+static int
+computeSignal (int exceptionVector)
+{
+  int sigval;
+  switch (exceptionVector)
+    {
+    case 0:
+      sigval = 23;
+      break;			/* I/O trap                    */
+    case 1:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 2:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 3:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 4:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 5:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 6:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 7:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 8:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 9:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 10:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 11:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 12:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 13:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 14:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 15:
+      sigval = 5;
+      break;			/* breakpoint                  */
+    case 16:
+      sigval = 10;
+      break;			/* BUS ERROR (alignment)       */
+    case 17:
+      sigval = 2;
+      break;			/* INTerrupt                   */
+    default:
+      sigval = 7;
+      break;			/* "software generated"        */
+    }
+  return (sigval);
+}
+
+/**********************************************/
+/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */
+/* RETURN NUMBER OF CHARS PROCESSED           */
+/**********************************************/
+static int
+hexToInt (unsigned char **ptr, int *intValue)
+{
+  int numChars = 0;
+  int hexValue;
+
+  *intValue = 0;
+  while (**ptr)
+    {
+      hexValue = hex (**ptr);
+      if (hexValue >= 0)
+	{
+	  *intValue = (*intValue << 4) | hexValue;
+	  numChars++;
+	}
+      else
+	break;
+      (*ptr)++;
+    }
+  return (numChars);
+}
+
+/*
+  Table of branch instructions:
+  
+  10B6		RTE	return from trap or exception
+  1FCr		JMP	jump
+  1ECr		JL	jump and link
+  7Fxx		BRA	branch
+  FFxxxxxx	BRA	branch (long)
+  B09rxxxx	BNEZ	branch not-equal-zero
+  Br1rxxxx	BNE	branch not-equal
+  7Dxx		BNC	branch not-condition
+  FDxxxxxx	BNC	branch not-condition (long)
+  B0Arxxxx	BLTZ	branch less-than-zero
+  B0Crxxxx	BLEZ	branch less-equal-zero
+  7Exx		BL	branch and link
+  FExxxxxx	BL	branch and link (long)
+  B0Drxxxx	BGTZ	branch greater-than-zero
+  B0Brxxxx	BGEZ	branch greater-equal-zero
+  B08rxxxx	BEQZ	branch equal-zero
+  Br0rxxxx	BEQ	branch equal
+  7Cxx		BC	branch condition
+  FCxxxxxx	BC	branch condition (long)
+  */
+
+static int
+isShortBranch (unsigned char *instr)
+{
+  unsigned char instr0 = instr[0] & 0x7F;	/* mask off high bit */
+
+  if (instr0 == 0x10 && instr[1] == 0xB6)	/* RTE */
+    return 1;			/* return from trap or exception */
+
+  if (instr0 == 0x1E || instr0 == 0x1F)	/* JL or JMP */
+    if ((instr[1] & 0xF0) == 0xC0)
+      return 2;			/* jump thru a register */
+
+  if (instr0 == 0x7C || instr0 == 0x7D ||	/* BC, BNC, BL, BRA */
+      instr0 == 0x7E || instr0 == 0x7F)
+    return 3;			/* eight bit PC offset */
+
+  return 0;
+}
+
+static int
+isLongBranch (unsigned char *instr)
+{
+  if (instr[0] == 0xFC || instr[0] == 0xFD ||	/* BRA, BNC, BL, BC */
+      instr[0] == 0xFE || instr[0] == 0xFF)	/* 24 bit relative */
+    return 4;
+  if ((instr[0] & 0xF0) == 0xB0)	/* 16 bit relative */
+    {
+      if ((instr[1] & 0xF0) == 0x00 ||	/* BNE, BEQ */
+	  (instr[1] & 0xF0) == 0x10)
+	return 5;
+      if (instr[0] == 0xB0)	/* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ, BEQZ */
+	if ((instr[1] & 0xF0) == 0x80 || (instr[1] & 0xF0) == 0x90 ||
+	    (instr[1] & 0xF0) == 0xA0 || (instr[1] & 0xF0) == 0xB0 ||
+	    (instr[1] & 0xF0) == 0xC0 || (instr[1] & 0xF0) == 0xD0)
+	  return 6;
+    }
+  return 0;
+}
+
+/* if address is NOT on a 4-byte boundary, or high-bit of instr is zero, 
+   then it's a 2-byte instruction, else it's a 4-byte instruction.  */
+
+#define INSTRUCTION_SIZE(addr) \
+    ((((int) addr & 2) || (((unsigned char *) addr)[0] & 0x80) == 0) ? 2 : 4)
+
+static int
+isBranch (unsigned char *instr)
+{
+  if (INSTRUCTION_SIZE (instr) == 2)
+    return isShortBranch (instr);
+  else
+    return isLongBranch (instr);
+}
+
+static int
+willBranch (unsigned char *instr, int branchCode)
+{
+  switch (branchCode)
+    {
+    case 0:
+      return 0;			/* not a branch */
+    case 1:
+      return 1;			/* RTE */
+    case 2:
+      return 1;			/* JL or JMP    */
+    case 3:			/* BC, BNC, BL, BRA (short) */
+    case 4:			/* BC, BNC, BL, BRA (long) */
+      switch (instr[0] & 0x0F)
+	{
+	case 0xC:		/* Branch if Condition Register */
+	  return (registers[CBR] != 0);
+	case 0xD:		/* Branch if NOT Condition Register */
+	  return (registers[CBR] == 0);
+	case 0xE:		/* Branch and Link */
+	case 0xF:		/* Branch (unconditional) */
+	  return 1;
+	default:		/* oops? */
+	  return 0;
+	}
+    case 5:			/* BNE, BEQ */
+      switch (instr[1] & 0xF0)
+	{
+	case 0x00:		/* Branch if r1 equal to r2 */
+	  return (registers[instr[0] & 0x0F] == registers[instr[1] & 0x0F]);
+	case 0x10:		/* Branch if r1 NOT equal to r2 */
+	  return (registers[instr[0] & 0x0F] != registers[instr[1] & 0x0F]);
+	default:		/* oops? */
+	  return 0;
+	}
+    case 6:			/* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ ,BEQZ */
+      switch (instr[1] & 0xF0)
+	{
+	case 0x80:		/* Branch if reg equal to zero */
+	  return (registers[instr[1] & 0x0F] == 0);
+	case 0x90:		/* Branch if reg NOT equal to zero */
+	  return (registers[instr[1] & 0x0F] != 0);
+	case 0xA0:		/* Branch if reg less than zero */
+	  return (registers[instr[1] & 0x0F] < 0);
+	case 0xB0:		/* Branch if reg greater or equal to zero */
+	  return (registers[instr[1] & 0x0F] >= 0);
+	case 0xC0:		/* Branch if reg less than or equal to zero */
+	  return (registers[instr[1] & 0x0F] <= 0);
+	case 0xD0:		/* Branch if reg greater than zero */
+	  return (registers[instr[1] & 0x0F] > 0);
+	default:		/* oops? */
+	  return 0;
+	}
+    default:			/* oops? */
+      return 0;
+    }
+}
+
+static int
+branchDestination (unsigned char *instr, int branchCode)
+{
+  switch (branchCode)
+    {
+    default:
+    case 0:			/* not a branch */
+      return 0;
+    case 1:			/* RTE */
+      return registers[BPC] & ~3;	/* pop BPC into PC */
+    case 2:			/* JL or JMP */
+      return registers[instr[1] & 0x0F] & ~3;	/* jump thru a register */
+    case 3:			/* BC, BNC, BL, BRA (short, 8-bit relative offset) */
+      return (((int) instr) & ~3) + ((char) instr[1] << 2);
+    case 4:			/* BC, BNC, BL, BRA (long, 24-bit relative offset) */
+      return ((int) instr +
+	      ((((char) instr[1] << 16) | (instr[2] << 8) | (instr[3])) <<
+	       2));
+    case 5:			/* BNE, BEQ (16-bit relative offset) */
+    case 6:			/* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ ,BEQZ (ditto) */
+      return ((int) instr + ((((char) instr[2] << 8) | (instr[3])) << 2));
+    }
+
+  /* An explanatory note: in the last three return expressions, I have
+     cast the most-significant byte of the return offset to char.
+     What this accomplishes is sign extension.  If the other
+     less-significant bytes were signed as well, they would get sign
+     extended too and, if negative, their leading bits would clobber
+     the bits of the more-significant bytes ahead of them.  There are
+     other ways I could have done this, but sign extension from
+     odd-sized integers is always a pain. */
+}
+
+static void
+branchSideEffects (unsigned char *instr, int branchCode)
+{
+  switch (branchCode)
+    {
+    case 1:			/* RTE */
+      return;			/* I <THINK> this is already handled... */
+    case 2:			/* JL (or JMP) */
+    case 3:			/* BL (or BC, BNC, BRA) */
+    case 4:
+      if ((instr[0] & 0x0F) == 0x0E)	/* branch/jump and link */
+	registers[R14] = (registers[PC] & ~3) + 4;
+      return;
+    default:			/* any other branch has no side effects */
+      return;
+    }
+}
+
+static struct STEPPING_CONTEXT
+{
+  int stepping;			/* true when we've started a single-step */
+  unsigned long target_addr;	/* the instr we're trying to execute */
+  unsigned long target_size;	/* the size of the target instr */
+  unsigned long noop_addr;	/* where we've inserted a no-op, if any */
+  unsigned long trap1_addr;	/* the trap following the target instr */
+  unsigned long trap2_addr;	/* the trap at a branch destination, if any */
+  unsigned short noop_save;	/* instruction overwritten by our no-op */
+  unsigned short trap1_save;	/* instruction overwritten by trap1 */
+  unsigned short trap2_save;	/* instruction overwritten by trap2 */
+  unsigned short continue_p;	/* true if NOT returning to gdb after step */
+} stepping;
+
+/* Function: prepare_to_step
+   Called from handle_exception to prepare the user program to single-step.
+   Places a trap instruction after the target instruction, with special 
+   extra handling for branch instructions and for instructions in the 
+   second half-word of a word.  
+
+   Returns: True  if we should actually execute the instruction; 
+	    False if we are going to emulate executing the instruction,
+	    in which case we simply report to GDB that the instruction 
+	    has already been executed.  */
+
+#define TRAP1  0x10f1;		/* trap #1 instruction */
+#define NOOP   0x7000;		/* noop    instruction */
+
+static unsigned short trap1 = TRAP1;
+static unsigned short noop = NOOP;
+
+static int
+prepare_to_step (continue_p)
+     int continue_p;		/* if this isn't REALLY a single-step (see below) */
+{
+  unsigned long pc = registers[PC];
+  int branchCode = isBranch ((unsigned char *) pc);
+  unsigned char *p;
+
+  /* zero out the stepping context 
+     (paranoia -- it should already be zeroed) */
+  for (p = (unsigned char *) &stepping;
+       p < ((unsigned char *) &stepping) + sizeof (stepping); p++)
+    *p = 0;
+
+  if (branchCode != 0)		/* next instruction is a branch */
+    {
+      branchSideEffects ((unsigned char *) pc, branchCode);
+      if (willBranch ((unsigned char *) pc, branchCode))
+	registers[PC] = branchDestination ((unsigned char *) pc, branchCode);
+      else
+	registers[PC] = pc + INSTRUCTION_SIZE (pc);
+      return 0;			/* branch "executed" -- just notify GDB */
+    }
+  else if (((int) pc & 2) != 0)	/* "second-slot" instruction */
+    {
+      /* insert no-op before pc */
+      stepping.noop_addr = pc - 2;
+      stepping.noop_save = *(unsigned short *) stepping.noop_addr;
+      *(unsigned short *) stepping.noop_addr = noop;
+      /* insert trap  after  pc */
+      stepping.trap1_addr = pc + 2;
+      stepping.trap1_save = *(unsigned short *) stepping.trap1_addr;
+      *(unsigned short *) stepping.trap1_addr = trap1;
+    }
+  else				/* "first-slot" instruction */
+    {
+      /* insert trap  after  pc */
+      stepping.trap1_addr = pc + INSTRUCTION_SIZE (pc);
+      stepping.trap1_save = *(unsigned short *) stepping.trap1_addr;
+      *(unsigned short *) stepping.trap1_addr = trap1;
+    }
+  /* "continue_p" means that we are actually doing a continue, and not 
+     being requested to single-step by GDB.  Sometimes we have to do
+     one single-step before continuing, because the PC is on a half-word
+     boundary.  There's no way to simply resume at such an address.  */
+  stepping.continue_p = continue_p;
+  stepping.stepping = 1;	/* starting a single-step */
+  return 1;
+}
+
+/* Function: finish_from_step
+   Called from handle_exception to finish up when the user program 
+   returns from a single-step.  Replaces the instructions that had
+   been overwritten by traps or no-ops, 
+
+   Returns: True  if we should notify GDB that the target stopped.
+	    False if we only single-stepped because we had to before we
+	    could continue (ie. we were trying to continue at a 
+	    half-word boundary).  In that case don't notify GDB:
+	    just "continue continuing".  */
+
+static int
+finish_from_step (void)
+{
+  if (stepping.stepping)	/* anything to do? */
+    {
+      int continue_p = stepping.continue_p;
+      unsigned char *p;
+
+      if (stepping.noop_addr)	/* replace instr "under" our no-op */
+	*(unsigned short *) stepping.noop_addr = stepping.noop_save;
+      if (stepping.trap1_addr)	/* replace instr "under" our trap  */
+	*(unsigned short *) stepping.trap1_addr = stepping.trap1_save;
+      if (stepping.trap2_addr)	/* ditto our other trap, if any    */
+	*(unsigned short *) stepping.trap2_addr = stepping.trap2_save;
+
+      for (p = (unsigned char *) &stepping;	/* zero out the stepping context */
+	   p < ((unsigned char *) &stepping) + sizeof (stepping); p++)
+	*p = 0;
+
+      return !(continue_p);
+    }
+  else				/* we didn't single-step, therefore this must be a legitimate stop */
+    return 1;
+}
+
+struct PSWreg
+{				/* separate out the bit flags in the PSW register */
+  int pad1:16;
+  int bsm:1;
+  int bie:1;
+  int pad2:5;
+  int bc:1;
+  int sm:1;
+  int ie:1;
+  int pad3:5;
+  int c:1;
+} *psw;
+
+/* Upon entry the value for LR to save has been pushed.
+   We unpush that so that the value for the stack pointer saved is correct.
+   Upon entry, all other registers are assumed to have not been modified
+   since the interrupt/trap occured.  */
+
+asm ("\n\
+stash_registers:\n\
+	push r0\n\
+	push r1\n\
+	seth r1, #shigh(registers)\n\
+	add3 r1, r1, #low(registers)\n\
+	pop r0		; r1\n\
+	st r0, @(4,r1)\n\
+	pop r0		; r0\n\
+	st r0, @r1\n\
+	addi r1, #4	; only add 4 as subsequent saves are `pre inc'\n\
+	st r2, @+r1\n\
+	st r3, @+r1\n\
+	st r4, @+r1\n\
+	st r5, @+r1\n\
+	st r6, @+r1\n\
+	st r7, @+r1\n\
+	st r8, @+r1\n\
+	st r9, @+r1\n\
+	st r10, @+r1\n\
+	st r11, @+r1\n\
+	st r12, @+r1\n\
+	st r13, @+r1    ; fp\n\
+	pop r0		; lr (r14)\n\
+	st r0, @+r1\n\
+	st sp, @+r1	; sp contains right value at this point\n\
+	mvfc r0, cr0\n\
+	st r0, @+r1	; cr0 == PSW\n\
+	mvfc r0, cr1\n\
+	st r0, @+r1	; cr1 == CBR\n\
+	mvfc r0, cr2\n\
+	st r0, @+r1	; cr2 == SPI\n\
+	mvfc r0, cr3\n\
+	st r0, @+r1	; cr3 == SPU\n\
+	mvfc r0, cr6\n\
+	st r0, @+r1	; cr6 == BPC\n\
+	st r0, @+r1	; PC  == BPC\n\
+	mvfaclo r0\n\
+	st r0, @+r1	; ACCL\n\
+	mvfachi r0\n\
+	st r0, @+r1	; ACCH\n\
+	jmp lr");
+
+/* C routine to clean up what stash_registers did.
+   It is called after calling stash_registers.
+   This is separate from stash_registers as we want to do this in C
+   but doing stash_registers in C isn't straightforward.  */
+
+static void
+cleanup_stash (void)
+{
+  psw = (struct PSWreg *) &registers[PSW];	/* fields of PSW register */
+  psw->sm = psw->bsm;		/* fix up pre-trap values of psw fields */
+  psw->ie = psw->bie;
+  psw->c = psw->bc;
+  registers[CBR] = psw->bc;	/* fix up pre-trap "C" register */
+
+#if 0				/* FIXME: Was in previous version.  Necessary?
+				   (Remember that we use the "rte" insn to return from the
+				   trap/interrupt so the values of bsm, bie, bc are important.  */
+  psw->bsm = psw->bie = psw->bc = 0;	/* zero post-trap values */
+#endif
+
+  /* FIXME: Copied from previous version.  This can probably be deleted
+     since methinks stash_registers has already done this.  */
+  registers[PC] = registers[BPC];	/* pre-trap PC */
+
+  /* FIXME: Copied from previous version.  Necessary?  */
+  if (psw->sm)			/* copy R15 into (psw->sm ? SPU : SPI) */
+    registers[SPU] = registers[R15];
+  else
+    registers[SPI] = registers[R15];
+}
+
+asm ("\n\
+restore_and_return:\n\
+	seth r0, #shigh(registers+8)\n\
+	add3 r0, r0, #low(registers+8)\n\
+	ld r2, @r0+	; restore r2\n\
+	ld r3, @r0+	; restore r3\n\
+	ld r4, @r0+	; restore r4\n\
+	ld r5, @r0+	; restore r5\n\
+	ld r6, @r0+	; restore r6\n\
+	ld r7, @r0+	; restore r7\n\
+	ld r8, @r0+	; restore r8\n\
+	ld r9, @r0+	; restore r9\n\
+	ld r10, @r0+	; restore r10\n\
+	ld r11, @r0+	; restore r11\n\
+	ld r12, @r0+	; restore r12\n\
+	ld r13, @r0+	; restore r13\n\
+	ld r14, @r0+	; restore r14\n\
+	ld r15, @r0+	; restore r15\n\
+	ld r1, @r0+	; restore cr0 == PSW\n\
+	mvtc r1, cr0\n\
+	ld r1, @r0+	; restore cr1 == CBR (no-op, because it's read only)\n\
+	mvtc r1, cr1\n\
+	ld r1, @r0+	; restore cr2 == SPI\n\
+	mvtc r1, cr2\n\
+	ld r1, @r0+	; restore cr3 == SPU\n\
+	mvtc r1, cr3\n\
+	addi r0, #4	; skip BPC\n\
+	ld r1, @r0+	; restore cr6 (BPC) == PC\n\
+	mvtc r1, cr6\n\
+	ld r1, @r0+	; restore ACCL\n\
+	mvtaclo r1\n\
+	ld r1, @r0+	; restore ACCH\n\
+	mvtachi r1\n\
+	seth r0, #shigh(registers)\n\
+	add3 r0, r0, #low(registers)\n\
+	ld r1, @(4,r0)	; restore r1\n\
+	ld r0, @r0	; restore r0\n\
+	rte");
+
+/* General trap handler, called after the registers have been stashed.
+   NUM is the trap/exception number.  */
+
+static void
+process_exception (int num)
+{
+  cleanup_stash ();
+  asm volatile ("\n\
+	seth r1, #shigh(stackPtr)\n\
+	add3 r1, r1, #low(stackPtr)\n\
+	ld r15, @r1		; setup local stack (protect user stack)\n\
+	mv r0, %0\n\
+	bl handle_exception\n\
+	bl restore_and_return"::"r" (num):"r0", "r1");
+}
+
+void _catchException0 ();
+
+asm ("\n\
+_catchException0:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #0\n\
+	bl process_exception");
+
+void _catchException1 ();
+
+asm ("\n\
+_catchException1:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	bl cleanup_stash\n\
+	seth r1, #shigh(stackPtr)\n\
+	add3 r1, r1, #low(stackPtr)\n\
+	ld r15, @r1		; setup local stack (protect user stack)\n\
+	seth r1, #shigh(registers + 21*4) ; PC\n\
+	add3 r1, r1, #low(registers + 21*4)\n\
+	ld r0, @r1\n\
+	addi r0, #-4		; back up PC for breakpoint trap.\n\
+	st r0, @r1		; FIXME: what about bp in right slot?\n\
+	ldi r0, #1\n\
+	bl handle_exception\n\
+	bl restore_and_return");
+
+void _catchException2 ();
+
+asm ("\n\
+_catchException2:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #2\n\
+	bl process_exception");
+
+void _catchException3 ();
+
+asm ("\n\
+_catchException3:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #3\n\
+	bl process_exception");
+
+void _catchException4 ();
+
+asm ("\n\
+_catchException4:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #4\n\
+	bl process_exception");
+
+void _catchException5 ();
+
+asm ("\n\
+_catchException5:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #5\n\
+	bl process_exception");
+
+void _catchException6 ();
+
+asm ("\n\
+_catchException6:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #6\n\
+	bl process_exception");
+
+void _catchException7 ();
+
+asm ("\n\
+_catchException7:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #7\n\
+	bl process_exception");
+
+void _catchException8 ();
+
+asm ("\n\
+_catchException8:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #8\n\
+	bl process_exception");
+
+void _catchException9 ();
+
+asm ("\n\
+_catchException9:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #9\n\
+	bl process_exception");
+
+void _catchException10 ();
+
+asm ("\n\
+_catchException10:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #10\n\
+	bl process_exception");
+
+void _catchException11 ();
+
+asm ("\n\
+_catchException11:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #11\n\
+	bl process_exception");
+
+void _catchException12 ();
+
+asm ("\n\
+_catchException12:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #12\n\
+	bl process_exception");
+
+void _catchException13 ();
+
+asm ("\n\
+_catchException13:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #13\n\
+	bl process_exception");
+
+void _catchException14 ();
+
+asm ("\n\
+_catchException14:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #14\n\
+	bl process_exception");
+
+void _catchException15 ();
+
+asm ("\n\
+_catchException15:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #15\n\
+	bl process_exception");
+
+void _catchException16 ();
+
+asm ("\n\
+_catchException16:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #16\n\
+	bl process_exception");
+
+void _catchException17 ();
+
+asm ("\n\
+_catchException17:\n\
+	push lr\n\
+	bl stash_registers\n\
+	; Note that at this point the pushed value of `lr' has been popped\n\
+	ldi r0, #17\n\
+	bl process_exception");
+
+
+/* this function is used to set up exception handlers for tracing and
+   breakpoints */
+void
+set_debug_traps (void)
+{
+  /*  extern void remcomHandler(); */
+  int i;
+
+  for (i = 0; i < 18; i++)	/* keep a copy of old vectors */
+    if (save_vectors[i] == 0)	/* only copy them the first time */
+      save_vectors[i] = getExceptionHandler (i);
+
+  stackPtr = &remcomStack[STACKSIZE / sizeof (int) - 1];
+
+  exceptionHandler (0, _catchException0);
+  exceptionHandler (1, _catchException1);
+  exceptionHandler (2, _catchException2);
+  exceptionHandler (3, _catchException3);
+  exceptionHandler (4, _catchException4);
+  exceptionHandler (5, _catchException5);
+  exceptionHandler (6, _catchException6);
+  exceptionHandler (7, _catchException7);
+  exceptionHandler (8, _catchException8);
+  exceptionHandler (9, _catchException9);
+  exceptionHandler (10, _catchException10);
+  exceptionHandler (11, _catchException11);
+  exceptionHandler (12, _catchException12);
+  exceptionHandler (13, _catchException13);
+  exceptionHandler (14, _catchException14);
+  exceptionHandler (15, _catchException15);
+  exceptionHandler (16, _catchException16);
+  /*  exceptionHandler (17, _catchException17); */
+
+  initialized = 1;
+}
+
+/* This function will generate a breakpoint exception.  It is used at the
+   beginning of a program to sync up with a debugger and can be used
+   otherwise as a quick means to stop program execution and "break" into
+   the debugger. */
+
+#define BREAKPOINT() asm volatile ("	trap #2");
+
+void
+breakpoint (void)
+{
+  if (initialized)
+    BREAKPOINT ();
+}
+
+/* STDOUT section:
+   Stuff pertaining to simulating stdout by sending chars to gdb to be echoed.
+   Functions: gdb_putchar(char ch)
+              gdb_puts(char *str)
+              gdb_write(char *str, int len)
+              gdb_error(char *format, char *parm)
+	      */
+
+/* Function: gdb_putchar(int)
+   Make gdb write a char to stdout.
+   Returns: the char */
+
+static int
+gdb_putchar (int ch)
+{
+  char buf[4];
+
+  buf[0] = 'O';
+  buf[1] = hexchars[ch >> 4];
+  buf[2] = hexchars[ch & 0x0F];
+  buf[3] = 0;
+  putpacket (buf);
+  return ch;
+}
+
+/* Function: gdb_write(char *, int)
+   Make gdb write n bytes to stdout (not assumed to be null-terminated).
+   Returns: number of bytes written */
+
+static int
+gdb_write (char *data, int len)
+{
+  char *buf, *cpy;
+  int i;
+
+  buf = remcomOutBuffer;
+  buf[0] = 'O';
+  i = 0;
+  while (i < len)
+    {
+      for (cpy = buf + 1;
+	   i < len && cpy < buf + sizeof (remcomOutBuffer) - 3; i++)
+	{
+	  *cpy++ = hexchars[data[i] >> 4];
+	  *cpy++ = hexchars[data[i] & 0x0F];
+	}
+      *cpy = 0;
+      putpacket (buf);
+    }
+  return len;
+}
+
+/* Function: gdb_puts(char *)
+   Make gdb write a null-terminated string to stdout.
+   Returns: the length of the string */
+
+static int
+gdb_puts (char *str)
+{
+  return gdb_write (str, strlen (str));
+}
+
+/* Function: gdb_error(char *, char *)
+   Send an error message to gdb's stdout.
+   First string may have 1 (one) optional "%s" in it, which
+   will cause the optional second string to be inserted.  */
+
+static void
+gdb_error (char *format, char *parm)
+{
+  char buf[400], *cpy;
+  int len;
+
+  if (remote_debug)
+    {
+      if (format && *format)
+	len = strlen (format);
+      else
+	return;			/* empty input */
+
+      if (parm && *parm)
+	len += strlen (parm);
+
+      for (cpy = buf; *format;)
+	{
+	  if (format[0] == '%' && format[1] == 's')	/* include second string */
+	    {
+	      format += 2;	/* advance two chars instead of just one */
+	      while (parm && *parm)
+		*cpy++ = *parm++;
+	    }
+	  else
+	    *cpy++ = *format++;
+	}
+      *cpy = '\0';
+      gdb_puts (buf);
+    }
+}
+
+static unsigned char *
+strcpy (unsigned char *dest, const unsigned char *src)
+{
+  unsigned char *ret = dest;
+
+  if (dest && src)
+    {
+      while (*src)
+	*dest++ = *src++;
+      *dest = 0;
+    }
+  return ret;
+}
+
+static int
+strlen (const unsigned char *src)
+{
+  int ret;
+
+  for (ret = 0; *src; src++)
+    ret++;
+
+  return ret;
+}
+
+#if 0
+void
+exit (code)
+     int code;
+{
+  _exit (code);
+}
+
+int
+atexit (void *p)
+{
+  return 0;
+}
+
+void
+abort (void)
+{
+  _exit (1);
+}
+#endif
diff --git a/gdb/stubs/m68k-stub.c b/gdb/stubs/m68k-stub.c
new file mode 100644
index 00000000000..4ef4069bc3d
--- /dev/null
+++ b/gdb/stubs/m68k-stub.c
@@ -0,0 +1,1098 @@
+/****************************************************************************
+
+		THIS SOFTWARE IS NOT COPYRIGHTED  
+   
+   HP offers the following for use in the public domain.  HP makes no
+   warranty with regard to the software or it's performance and the 
+   user accepts the software "AS IS" with all faults.
+
+   HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
+   TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+
+****************************************************************************/
+
+/****************************************************************************
+ *  Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $                   
+ *
+ *  Module name: remcom.c $  
+ *  Revision: 1.34 $
+ *  Date: 91/03/09 12:29:49 $
+ *  Contributor:     Lake Stevens Instrument Division$
+ *  
+ *  Description:     low level support for gdb debugger. $
+ *
+ *  Considerations:  only works on target hardware $
+ *
+ *  Written by:      Glenn Engel $
+ *  ModuleState:     Experimental $ 
+ *
+ *  NOTES:           See Below $
+ * 
+ *  To enable debugger support, two things need to happen.  One, a
+ *  call to set_debug_traps() is necessary in order to allow any breakpoints
+ *  or error conditions to be properly intercepted and reported to gdb.
+ *  Two, a breakpoint needs to be generated to begin communication.  This
+ *  is most easily accomplished by a call to breakpoint().  Breakpoint()
+ *  simulates a breakpoint by executing a trap #1.  The breakpoint instruction
+ *  is hardwired to trap #1 because not to do so is a compatibility problem--
+ *  there either should be a standard breakpoint instruction, or the protocol
+ *  should be extended to provide some means to communicate which breakpoint
+ *  instruction is in use (or have the stub insert the breakpoint).
+ *  
+ *  Some explanation is probably necessary to explain how exceptions are
+ *  handled.  When an exception is encountered the 68000 pushes the current
+ *  program counter and status register onto the supervisor stack and then
+ *  transfers execution to a location specified in it's vector table.
+ *  The handlers for the exception vectors are hardwired to jmp to an address
+ *  given by the relation:  (exception - 256) * 6.  These are decending 
+ *  addresses starting from -6, -12, -18, ...  By allowing 6 bytes for
+ *  each entry, a jsr, jmp, bsr, ... can be used to enter the exception 
+ *  handler.  Using a jsr to handle an exception has an added benefit of
+ *  allowing a single handler to service several exceptions and use the
+ *  return address as the key differentiation.  The vector number can be
+ *  computed from the return address by [ exception = (addr + 1530) / 6 ].
+ *  The sole purpose of the routine _catchException is to compute the
+ *  exception number and push it on the stack in place of the return address.
+ *  The external function exceptionHandler() is
+ *  used to attach a specific handler to a specific m68k exception.
+ *  For 68020 machines, the ability to have a return address around just
+ *  so the vector can be determined is not necessary because the '020 pushes an
+ *  extra word onto the stack containing the vector offset
+ * 
+ *  Because gdb will sometimes write to the stack area to execute function
+ *  calls, this program cannot rely on using the supervisor stack so it
+ *  uses it's own stack area reserved in the int array remcomStack.  
+ * 
+ *************
+ *
+ *    The following gdb commands are supported:
+ * 
+ * command          function                               Return value
+ * 
+ *    g             return the value of the CPU registers  hex data or ENN
+ *    G             set the value of the CPU registers     OK or ENN
+ * 
+ *    mAA..AA,LLLL  Read LLLL bytes at address AA..AA      hex data or ENN
+ *    MAA..AA,LLLL: Write LLLL bytes at address AA.AA      OK or ENN
+ * 
+ *    c             Resume at current address              SNN   ( signal NN)
+ *    cAA..AA       Continue at address AA..AA             SNN
+ * 
+ *    s             Step one instruction                   SNN
+ *    sAA..AA       Step one instruction from AA..AA       SNN
+ * 
+ *    k             kill
+ *
+ *    ?             What was the last sigval ?             SNN   (signal NN)
+ * 
+ * All commands and responses are sent with a packet which includes a 
+ * checksum.  A packet consists of 
+ * 
+ * $<packet info>#<checksum>.
+ * 
+ * where
+ * <packet info> :: <characters representing the command or response>
+ * <checksum>    :: < two hex digits computed as modulo 256 sum of <packetinfo>>
+ * 
+ * When a packet is received, it is first acknowledged with either '+' or '-'.
+ * '+' indicates a successful transfer.  '-' indicates a failed transfer.
+ * 
+ * Example:
+ * 
+ * Host:                  Reply:
+ * $m0,10#2a               +$00010203040506070809101112131415#42
+ * 
+ ****************************************************************************/
+
+#include <stdio.h>
+#include <string.h>
+#include <setjmp.h>
+
+/************************************************************************
+ *
+ * external low-level support routines 
+ */
+typedef void (*ExceptionHook)(int);   /* pointer to function with int parm */
+typedef void (*Function)();           /* pointer to a function */
+
+extern void putDebugChar();	/* write a single character      */
+extern int getDebugChar();	/* read and return a single char */
+
+extern Function exceptionHandler();  /* assign an exception handler */
+extern ExceptionHook exceptionHook;  /* hook variable for errors/exceptions */
+
+/************************/
+/* FORWARD DECLARATIONS */
+/************************/
+static void
+initializeRemcomErrorFrame ();
+
+/************************************************************************/
+/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
+/* at least NUMREGBYTES*2 are needed for register packets */
+#define BUFMAX 400
+
+static char initialized;  /* boolean flag. != 0 means we've been initialized */
+
+int     remote_debug;
+/*  debug >  0 prints ill-formed commands in valid packets & checksum errors */ 
+
+static const char hexchars[]="0123456789abcdef";
+
+/* there are 180 bytes of registers on a 68020 w/68881      */
+/* many of the fpa registers are 12 byte (96 bit) registers */
+#define NUMREGBYTES 180
+enum regnames {D0,D1,D2,D3,D4,D5,D6,D7, 
+               A0,A1,A2,A3,A4,A5,A6,A7, 
+               PS,PC,
+               FP0,FP1,FP2,FP3,FP4,FP5,FP6,FP7,
+               FPCONTROL,FPSTATUS,FPIADDR
+              };
+
+
+/* We keep a whole frame cache here.  "Why?", I hear you cry, "doesn't
+   GDB handle that sort of thing?"  Well, yes, I believe the only
+   reason for this cache is to save and restore floating point state
+   (fsave/frestore).  A cleaner way to do this would be to make the
+ fsave data part of the registers which GDB deals with like any
+   other registers.  This should not be a performance problem if the
+   ability to read individual registers is added to the protocol.  */
+
+typedef struct FrameStruct
+{
+    struct FrameStruct  *previous;
+    int       exceptionPC;      /* pc value when this frame created */
+    int       exceptionVector;  /* cpu vector causing exception     */
+    short     frameSize;        /* size of cpu frame in words       */
+    short     sr;               /* for 68000, this not always sr    */
+    int       pc;
+    short     format;
+    int       fsaveHeader;
+    int       morejunk[0];        /* exception frame, fp save... */
+} Frame;
+
+#define FRAMESIZE 500
+int   gdbFrameStack[FRAMESIZE];
+static Frame *lastFrame;
+
+/*
+ * these should not be static cuz they can be used outside this module
+ */
+int registers[NUMREGBYTES/4];
+int superStack;
+
+#define STACKSIZE 10000
+int remcomStack[STACKSIZE/sizeof(int)];
+static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1];
+
+/*
+ * In many cases, the system will want to continue exception processing
+ * when a continue command is given.  
+ * oldExceptionHook is a function to invoke in this case.
+ */
+
+static ExceptionHook oldExceptionHook;
+
+#ifdef mc68020
+/* the size of the exception stack on the 68020 varies with the type of
+ * exception.  The following table is the number of WORDS used
+ * for each exception format.
+ */
+const short exceptionSize[] = { 4,4,6,4,4,4,4,4,29,10,16,46,12,4,4,4 };
+#endif
+
+#ifdef mc68332
+static const short exceptionSize[] = { 4,4,6,4,4,4,4,4,4,4,4,4,16,4,4,4 };
+#endif
+
+/************* jump buffer used for setjmp/longjmp **************************/
+jmp_buf remcomEnv;
+
+/***************************  ASSEMBLY CODE MACROS *************************/
+/* 									   */
+
+#ifdef __HAVE_68881__
+/* do an fsave, then remember the address to begin a restore from */
+#define SAVE_FP_REGS()    asm(" fsave   a0@-");		\
+			  asm(" fmovemx fp0-fp7,_registers+72");        \
+			  asm(" fmoveml fpcr/fpsr/fpi,_registers+168"); 
+#define RESTORE_FP_REGS()                              \
+asm("                                                \n\
+    fmoveml  _registers+168,fpcr/fpsr/fpi            \n\
+    fmovemx  _registers+72,fp0-fp7                   \n\
+    cmpl     #-1,a0@     |  skip frestore flag set ? \n\
+    beq      skip_frestore                           \n\
+    frestore a0@+                                    \n\
+skip_frestore:                                       \n\
+");
+
+#else
+#define SAVE_FP_REGS()
+#define RESTORE_FP_REGS()
+#endif /* __HAVE_68881__ */
+
+void return_to_super();
+void return_to_user();
+
+asm("
+.text
+.globl _return_to_super
+_return_to_super:
+        movel   _registers+60,sp /* get new stack pointer */        
+        movel   _lastFrame,a0   /* get last frame info  */              
+        bra     return_to_any
+
+.globl _return_to_user
+_return_to_user:
+        movel   _registers+60,a0 /* get usp */                          
+        movel   a0,usp           /* set usp */				
+        movel   _superStack,sp  /* get original stack pointer */        
+
+return_to_any:
+        movel   _lastFrame,a0   /* get last frame info  */              
+        movel   a0@+,_lastFrame /* link in previous frame     */        
+        addql   #8,a0           /* skip over pc, vector#*/              
+        movew   a0@+,d0         /* get # of words in cpu frame */       
+        addw    d0,a0           /* point to end of data        */       
+        addw    d0,a0           /* point to end of data        */       
+        movel   a0,a1                                                   
+#                                                                       
+# copy the stack frame                                                  
+        subql   #1,d0                                                   
+copyUserLoop:                                                               
+        movew   a1@-,sp@-                                               
+        dbf     d0,copyUserLoop                                             
+");                                                                     
+        RESTORE_FP_REGS()                                              
+   asm("   moveml  _registers,d0-d7/a0-a6");			        
+   asm("   rte");  /* pop and go! */                                    
+
+#define DISABLE_INTERRUPTS()   asm("         oriw   #0x0700,sr");
+#define BREAKPOINT() asm("   trap #1");
+
+/* this function is called immediately when a level 7 interrupt occurs */
+/* if the previous interrupt level was 7 then we're already servicing  */
+/* this interrupt and an rte is in order to return to the debugger.    */
+/* For the 68000, the offset for sr is 6 due to the jsr return address */
+asm("
+.text
+.globl __debug_level7
+__debug_level7:
+	movew   d0,sp@-");
+#if defined (mc68020) || defined (mc68332)
+asm("	movew   sp@(2),d0");
+#else
+asm("	movew   sp@(6),d0");
+#endif
+asm("	andiw   #0x700,d0
+	cmpiw   #0x700,d0
+	beq     _already7
+        movew   sp@+,d0	
+        bra     __catchException
+_already7:
+	movew   sp@+,d0");
+#if !defined (mc68020) && !defined (mc68332)
+asm("	lea     sp@(4),sp");     /* pull off 68000 return address */
+#endif
+asm("	rte");
+
+extern void _catchException ();
+
+#if defined (mc68020) || defined (mc68332)
+/* This function is called when a 68020 exception occurs.  It saves
+ * all the cpu and fpcp regs in the _registers array, creates a frame on a
+ * linked list of frames which has the cpu and fpcp stack frames needed
+ * to properly restore the context of these processors, and invokes
+ * an exception handler (remcom_handler).
+ *
+ * stack on entry:                       stack on exit:
+ *   N bytes of junk                     exception # MSWord
+ *   Exception Format Word               exception # MSWord
+ *   Program counter LSWord              
+ *   Program counter MSWord             
+ *   Status Register                    
+ *                                       
+ *                                       
+ */
+asm(" 
+.text
+.globl __catchException
+__catchException:");
+DISABLE_INTERRUPTS();
+asm("
+        moveml  d0-d7/a0-a6,_registers /* save registers        */
+	movel	_lastFrame,a0	/* last frame pointer */
+");
+SAVE_FP_REGS();        
+asm("
+	lea     _registers,a5   /* get address of registers     */
+        movew   sp@,d1          /* get status register          */
+        movew   d1,a5@(66)      /* save sr		 	*/	
+	movel   sp@(2),a4       /* save pc in a4 for later use  */
+        movel   a4,a5@(68)      /* save pc in _regisers[]      	*/
+
+#
+# figure out how many bytes in the stack frame
+	movew   sp@(6),d0	/* get '020 exception format	*/
+        movew   d0,d2           /* make a copy of format word   */
+        andiw   #0xf000,d0      /* mask off format type         */
+        rolw    #5,d0           /* rotate into the low byte *2  */
+        lea     _exceptionSize,a1   
+        addw    d0,a1           /* index into the table         */
+	movew   a1@,d0          /* get number of words in frame */
+        movew   d0,d3           /* save it                      */
+        subw    d0,a0		/* adjust save pointer          */
+        subw    d0,a0		/* adjust save pointer(bytes)   */
+	movel   a0,a1           /* copy save pointer            */
+	subql   #1,d0           /* predecrement loop counter    */
+#
+# copy the frame
+saveFrameLoop:
+	movew  	sp@+,a1@+
+	dbf     d0,saveFrameLoop
+#
+# now that the stack has been clenaed,
+# save the a7 in use at time of exception
+        movel   sp,_superStack  /* save supervisor sp           */
+        andiw   #0x2000,d1      /* were we in supervisor mode ? */
+        beq     userMode       
+        movel   a7,a5@(60)      /* save a7                  */
+        bra     a7saveDone
+userMode:  
+	movel   usp,a1    	
+        movel   a1,a5@(60)      /* save user stack pointer	*/
+a7saveDone:
+
+#
+# save size of frame
+        movew   d3,a0@-
+
+#
+# compute exception number
+	andl    #0xfff,d2   	/* mask off vector offset	*/
+	lsrw    #2,d2   	/* divide by 4 to get vect num	*/
+        movel   d2,a0@-         /* save it                      */
+#
+# save pc causing exception
+        movel   a4,a0@-
+#
+# save old frame link and set the new value
+	movel	_lastFrame,a1	/* last frame pointer */
+	movel   a1,a0@-		/* save pointer to prev frame	*/
+        movel   a0,_lastFrame
+
+        movel   d2,sp@-		/* push exception num           */
+	movel   _exceptionHook,a0  /* get address of handler */
+        jbsr    a0@             /* and call it */
+        clrl    sp@             /* replace exception num parm with frame ptr */
+        jbsr     __returnFromException   /* jbsr, but never returns */
+");
+#else /* mc68000 */
+/* This function is called when an exception occurs.  It translates the
+ * return address found on the stack into an exception vector # which
+ * is then handled by either handle_exception or a system handler.
+ * _catchException provides a front end for both.  
+ *
+ * stack on entry:                       stack on exit:
+ *   Program counter MSWord              exception # MSWord 
+ *   Program counter LSWord              exception # MSWord
+ *   Status Register                     
+ *   Return Address  MSWord              
+ *   Return Address  LSWord             
+ */
+asm("
+.text
+.globl __catchException
+__catchException:");
+DISABLE_INTERRUPTS();
+asm("
+        moveml d0-d7/a0-a6,_registers  /* save registers               */
+	movel	_lastFrame,a0	/* last frame pointer */
+");
+SAVE_FP_REGS();        
+asm("
+        lea     _registers,a5   /* get address of registers     */
+        movel   sp@+,d2         /* pop return address           */
+	addl 	#1530,d2        /* convert return addr to 	*/
+	divs 	#6,d2   	/*  exception number		*/
+	extl    d2   
+
+        moveql  #3,d3           /* assume a three word frame     */
+
+        cmpiw   #3,d2           /* bus error or address error ? */
+        bgt     normal          /* if >3 then normal error      */
+        movel   sp@+,a0@-       /* copy error info to frame buff*/
+        movel   sp@+,a0@-       /* these are never used         */
+        moveql  #7,d3           /* this is a 7 word frame       */
+     
+normal:   
+	movew   sp@+,d1         /* pop status register          */
+        movel   sp@+,a4         /* pop program counter          */
+        movew   d1,a5@(66)      /* save sr		 	*/	
+        movel   a4,a5@(68)      /* save pc in _regisers[]      	*/
+        movel   a4,a0@-         /* copy pc to frame buffer      */
+	movew   d1,a0@-         /* copy sr to frame buffer      */
+
+        movel   sp,_superStack  /* save supervisor sp          */
+
+        andiw   #0x2000,d1      /* were we in supervisor mode ? */
+        beq     userMode       
+        movel   a7,a5@(60)      /* save a7                  */
+        bra     saveDone             
+userMode:
+        movel   usp,a1    	/* save user stack pointer 	*/
+        movel   a1,a5@(60)      /* save user stack pointer	*/
+saveDone:
+
+        movew   d3,a0@-         /* push frame size in words     */
+        movel   d2,a0@-         /* push vector number           */
+        movel   a4,a0@-         /* push exception pc            */
+
+#
+# save old frame link and set the new value
+	movel	_lastFrame,a1	/* last frame pointer */
+	movel   a1,a0@-		/* save pointer to prev frame	*/
+        movel   a0,_lastFrame
+
+        movel   d2,sp@-		/* push exception num           */
+	movel   _exceptionHook,a0  /* get address of handler */
+        jbsr    a0@             /* and call it */
+        clrl    sp@             /* replace exception num parm with frame ptr */
+        jbsr     __returnFromException   /* jbsr, but never returns */
+");
+#endif
+
+
+/*
+ * remcomHandler is a front end for handle_exception.  It moves the
+ * stack pointer into an area reserved for debugger use in case the
+ * breakpoint happened in supervisor mode.
+ */
+asm("_remcomHandler:");
+asm("           addl    #4,sp");        /* pop off return address     */
+asm("           movel   sp@+,d0");      /* get the exception number   */
+asm("		movel   _stackPtr,sp"); /* move to remcom stack area  */
+asm("		movel   d0,sp@-");	/* push exception onto stack  */
+asm("		jbsr    _handle_exception");    /* this never returns */
+asm("           rts");                  /* return */
+
+void
+_returnFromException (Frame * frame)
+{
+  /* if no passed in frame, use the last one */
+  if (!frame)
+    {
+      frame = lastFrame;
+      frame->frameSize = 4;
+      frame->format = 0;
+      frame->fsaveHeader = -1;	/* restore regs, but we dont have fsave info */
+    }
+
+#if !defined (mc68020) && !defined (mc68332)
+  /* a 68000 cannot use the internal info pushed onto a bus error
+   * or address error frame when doing an RTE so don't put this info
+   * onto the stack or the stack will creep every time this happens.
+   */
+  frame->frameSize = 3;
+#endif
+
+  /* throw away any frames in the list after this frame */
+  lastFrame = frame;
+
+  frame->sr = registers[(int) PS];
+  frame->pc = registers[(int) PC];
+
+  if (registers[(int) PS] & 0x2000)
+    {
+      /* return to supervisor mode... */
+      return_to_super ();
+    }
+  else
+    {				/* return to user mode */
+      return_to_user ();
+    }
+}
+
+int
+hex (ch)
+     char ch;
+{
+  if ((ch >= 'a') && (ch <= 'f'))
+    return (ch - 'a' + 10);
+  if ((ch >= '0') && (ch <= '9'))
+    return (ch - '0');
+  if ((ch >= 'A') && (ch <= 'F'))
+    return (ch - 'A' + 10);
+  return (-1);
+}
+
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
+
+/* scan for the sequence $<data>#<checksum>     */
+
+unsigned char *
+getpacket (void)
+{
+  unsigned char *buffer = &remcomInBuffer[0];
+  unsigned char checksum;
+  unsigned char xmitcsum;
+  int count;
+  char ch;
+
+  while (1)
+    {
+      /* wait around for the start character, ignore all other characters */
+      while ((ch = getDebugChar ()) != '$')
+	;
+
+    retry:
+      checksum = 0;
+      xmitcsum = -1;
+      count = 0;
+
+      /* now, read until a # or end of buffer is found */
+      while (count < BUFMAX - 1)
+	{
+	  ch = getDebugChar ();
+	  if (ch == '$')
+	    goto retry;
+	  if (ch == '#')
+	    break;
+	  checksum = checksum + ch;
+	  buffer[count] = ch;
+	  count = count + 1;
+	}
+      buffer[count] = 0;
+
+      if (ch == '#')
+	{
+	  ch = getDebugChar ();
+	  xmitcsum = hex (ch) << 4;
+	  ch = getDebugChar ();
+	  xmitcsum += hex (ch);
+
+	  if (checksum != xmitcsum)
+	    {
+	      if (remote_debug)
+		{
+		  fprintf (stderr,
+			   "bad checksum.  My count = 0x%x, sent=0x%x. buf=%s\n",
+			   checksum, xmitcsum, buffer);
+		}
+	      putDebugChar ('-');	/* failed checksum */
+	    }
+	  else
+	    {
+	      putDebugChar ('+');	/* successful transfer */
+
+	      /* if a sequence char is present, reply the sequence ID */
+	      if (buffer[2] == ':')
+		{
+		  putDebugChar (buffer[0]);
+		  putDebugChar (buffer[1]);
+
+		  return &buffer[3];
+		}
+
+	      return &buffer[0];
+	    }
+	}
+    }
+}
+
+/* send the packet in buffer. */
+
+void
+putpacket (buffer)
+     char *buffer;
+{
+  unsigned char checksum;
+  int count;
+  char ch;
+
+  /*  $<packet info>#<checksum>. */
+  do
+    {
+      putDebugChar ('$');
+      checksum = 0;
+      count = 0;
+
+      while (ch = buffer[count])
+	{
+	  putDebugChar (ch);
+	  checksum += ch;
+	  count += 1;
+	}
+
+      putDebugChar ('#');
+      putDebugChar (hexchars[checksum >> 4]);
+      putDebugChar (hexchars[checksum % 16]);
+
+    }
+  while (getDebugChar () != '+');
+
+}
+
+void
+debug_error (format, parm)
+     char *format;
+     char *parm;
+{
+  if (remote_debug)
+    fprintf (stderr, format, parm);
+}
+
+/* convert the memory pointed to by mem into hex, placing result in buf */
+/* return a pointer to the last char put in buf (null) */
+char *
+mem2hex (mem, buf, count)
+     char *mem;
+     char *buf;
+     int count;
+{
+  int i;
+  unsigned char ch;
+  for (i = 0; i < count; i++)
+    {
+      ch = *mem++;
+      *buf++ = hexchars[ch >> 4];
+      *buf++ = hexchars[ch % 16];
+    }
+  *buf = 0;
+  return (buf);
+}
+
+/* convert the hex array pointed to by buf into binary to be placed in mem */
+/* return a pointer to the character AFTER the last byte written */
+char *
+hex2mem (buf, mem, count)
+     char *buf;
+     char *mem;
+     int count;
+{
+  int i;
+  unsigned char ch;
+  for (i = 0; i < count; i++)
+    {
+      ch = hex (*buf++) << 4;
+      ch = ch + hex (*buf++);
+      *mem++ = ch;
+    }
+  return (mem);
+}
+
+/* a bus error has occurred, perform a longjmp
+   to return execution and allow handling of the error */
+
+void
+handle_buserror ()
+{
+  longjmp (remcomEnv, 1);
+}
+
+/* this function takes the 68000 exception number and attempts to 
+   translate this number into a unix compatible signal value */
+int
+computeSignal (exceptionVector)
+     int exceptionVector;
+{
+  int sigval;
+  switch (exceptionVector)
+    {
+    case 2:
+      sigval = 10;
+      break;			/* bus error           */
+    case 3:
+      sigval = 10;
+      break;			/* address error       */
+    case 4:
+      sigval = 4;
+      break;			/* illegal instruction */
+    case 5:
+      sigval = 8;
+      break;			/* zero divide         */
+    case 6:
+      sigval = 8;
+      break;			/* chk instruction     */
+    case 7:
+      sigval = 8;
+      break;			/* trapv instruction   */
+    case 8:
+      sigval = 11;
+      break;			/* privilege violation */
+    case 9:
+      sigval = 5;
+      break;			/* trace trap          */
+    case 10:
+      sigval = 4;
+      break;			/* line 1010 emulator  */
+    case 11:
+      sigval = 4;
+      break;			/* line 1111 emulator  */
+
+      /* Coprocessor protocol violation.  Using a standard MMU or FPU
+         this cannot be triggered by software.  Call it a SIGBUS.  */
+    case 13:
+      sigval = 10;
+      break;
+
+    case 31:
+      sigval = 2;
+      break;			/* interrupt           */
+    case 33:
+      sigval = 5;
+      break;			/* breakpoint          */
+
+      /* This is a trap #8 instruction.  Apparently it is someone's software
+         convention for some sort of SIGFPE condition.  Whose?  How many
+         people are being screwed by having this code the way it is?
+         Is there a clean solution?  */
+    case 40:
+      sigval = 8;
+      break;			/* floating point err  */
+
+    case 48:
+      sigval = 8;
+      break;			/* floating point err  */
+    case 49:
+      sigval = 8;
+      break;			/* floating point err  */
+    case 50:
+      sigval = 8;
+      break;			/* zero divide         */
+    case 51:
+      sigval = 8;
+      break;			/* underflow           */
+    case 52:
+      sigval = 8;
+      break;			/* operand error       */
+    case 53:
+      sigval = 8;
+      break;			/* overflow            */
+    case 54:
+      sigval = 8;
+      break;			/* NAN                 */
+    default:
+      sigval = 7;		/* "software generated" */
+    }
+  return (sigval);
+}
+
+/**********************************************/
+/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */
+/* RETURN NUMBER OF CHARS PROCESSED           */
+/**********************************************/
+int
+hexToInt (char **ptr, int *intValue)
+{
+  int numChars = 0;
+  int hexValue;
+
+  *intValue = 0;
+
+  while (**ptr)
+    {
+      hexValue = hex (**ptr);
+      if (hexValue >= 0)
+	{
+	  *intValue = (*intValue << 4) | hexValue;
+	  numChars++;
+	}
+      else
+	break;
+
+      (*ptr)++;
+    }
+
+  return (numChars);
+}
+
+/*
+ * This function does all command procesing for interfacing to gdb.
+ */
+void
+handle_exception (int exceptionVector)
+{
+  int sigval, stepping;
+  int addr, length;
+  char *ptr;
+  int newPC;
+  Frame *frame;
+
+  if (remote_debug)
+    printf ("vector=%d, sr=0x%x, pc=0x%x\n",
+	    exceptionVector, registers[PS], registers[PC]);
+
+  /* reply to host that an exception has occurred */
+  sigval = computeSignal (exceptionVector);
+  remcomOutBuffer[0] = 'S';
+  remcomOutBuffer[1] = hexchars[sigval >> 4];
+  remcomOutBuffer[2] = hexchars[sigval % 16];
+  remcomOutBuffer[3] = 0;
+
+  putpacket (remcomOutBuffer);
+
+  stepping = 0;
+
+  while (1 == 1)
+    {
+      remcomOutBuffer[0] = 0;
+      ptr = getpacket ();
+      switch (*ptr++)
+	{
+	case '?':
+	  remcomOutBuffer[0] = 'S';
+	  remcomOutBuffer[1] = hexchars[sigval >> 4];
+	  remcomOutBuffer[2] = hexchars[sigval % 16];
+	  remcomOutBuffer[3] = 0;
+	  break;
+	case 'd':
+	  remote_debug = !(remote_debug);	/* toggle debug flag */
+	  break;
+	case 'g':		/* return the value of the CPU registers */
+	  mem2hex ((char *) registers, remcomOutBuffer, NUMREGBYTES);
+	  break;
+	case 'G':		/* set the value of the CPU registers - return OK */
+	  hex2mem (ptr, (char *) registers, NUMREGBYTES);
+	  strcpy (remcomOutBuffer, "OK");
+	  break;
+
+	  /* mAA..AA,LLLL  Read LLLL bytes at address AA..AA */
+	case 'm':
+	  if (setjmp (remcomEnv) == 0)
+	    {
+	      exceptionHandler (2, handle_buserror);
+
+	      /* TRY TO READ %x,%x.  IF SUCCEED, SET PTR = 0 */
+	      if (hexToInt (&ptr, &addr))
+		if (*(ptr++) == ',')
+		  if (hexToInt (&ptr, &length))
+		    {
+		      ptr = 0;
+		      mem2hex ((char *) addr, remcomOutBuffer, length);
+		    }
+
+	      if (ptr)
+		{
+		  strcpy (remcomOutBuffer, "E01");
+		}
+	    }
+	  else
+	    {
+	      exceptionHandler (2, _catchException);
+	      strcpy (remcomOutBuffer, "E03");
+	      debug_error ("bus error");
+	    }
+
+	  /* restore handler for bus error */
+	  exceptionHandler (2, _catchException);
+	  break;
+
+	  /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
+	case 'M':
+	  if (setjmp (remcomEnv) == 0)
+	    {
+	      exceptionHandler (2, handle_buserror);
+
+	      /* TRY TO READ '%x,%x:'.  IF SUCCEED, SET PTR = 0 */
+	      if (hexToInt (&ptr, &addr))
+		if (*(ptr++) == ',')
+		  if (hexToInt (&ptr, &length))
+		    if (*(ptr++) == ':')
+		      {
+			hex2mem (ptr, (char *) addr, length);
+			ptr = 0;
+			strcpy (remcomOutBuffer, "OK");
+		      }
+	      if (ptr)
+		{
+		  strcpy (remcomOutBuffer, "E02");
+		}
+	    }
+	  else
+	    {
+	      exceptionHandler (2, _catchException);
+	      strcpy (remcomOutBuffer, "E03");
+	      debug_error ("bus error");
+	    }
+
+	  /* restore handler for bus error */
+	  exceptionHandler (2, _catchException);
+	  break;
+
+	  /* cAA..AA    Continue at address AA..AA(optional) */
+	  /* sAA..AA   Step one instruction from AA..AA(optional) */
+	case 's':
+	  stepping = 1;
+	case 'c':
+	  /* try to read optional parameter, pc unchanged if no parm */
+	  if (hexToInt (&ptr, &addr))
+	    registers[PC] = addr;
+
+	  newPC = registers[PC];
+
+	  /* clear the trace bit */
+	  registers[PS] &= 0x7fff;
+
+	  /* set the trace bit if we're stepping */
+	  if (stepping)
+	    registers[PS] |= 0x8000;
+
+	  /*
+	   * look for newPC in the linked list of exception frames.
+	   * if it is found, use the old frame it.  otherwise,
+	   * fake up a dummy frame in returnFromException().
+	   */
+	  if (remote_debug)
+	    printf ("new pc = 0x%x\n", newPC);
+	  frame = lastFrame;
+	  while (frame)
+	    {
+	      if (remote_debug)
+		printf ("frame at 0x%x has pc=0x%x, except#=%d\n",
+			frame, frame->exceptionPC, frame->exceptionVector);
+	      if (frame->exceptionPC == newPC)
+		break;		/* bingo! a match */
+	      /*
+	       * for a breakpoint instruction, the saved pc may
+	       * be off by two due to re-executing the instruction
+	       * replaced by the trap instruction.  Check for this.
+	       */
+	      if ((frame->exceptionVector == 33) &&
+		  (frame->exceptionPC == (newPC + 2)))
+		break;
+	      if (frame == frame->previous)
+		{
+		  frame = 0;	/* no match found */
+		  break;
+		}
+	      frame = frame->previous;
+	    }
+
+	  /*
+	   * If we found a match for the PC AND we are not returning
+	   * as a result of a breakpoint (33),
+	   * trace exception (9), nmi (31), jmp to
+	   * the old exception handler as if this code never ran.
+	   */
+	  if (frame)
+	    {
+	      if ((frame->exceptionVector != 9) &&
+		  (frame->exceptionVector != 31) &&
+		  (frame->exceptionVector != 33))
+		{
+		  /*
+		   * invoke the previous handler.
+		   */
+		  if (oldExceptionHook)
+		    (*oldExceptionHook) (frame->exceptionVector);
+		  newPC = registers[PC];	/* pc may have changed  */
+		  if (newPC != frame->exceptionPC)
+		    {
+		      if (remote_debug)
+			printf ("frame at 0x%x has pc=0x%x, except#=%d\n",
+				frame, frame->exceptionPC,
+				frame->exceptionVector);
+		      /* re-use the last frame, we're skipping it (longjump?) */
+		      frame = (Frame *) 0;
+		      _returnFromException (frame);	/* this is a jump */
+		    }
+		}
+	    }
+
+	  /* if we couldn't find a frame, create one */
+	  if (frame == 0)
+	    {
+	      frame = lastFrame - 1;
+
+	      /* by using a bunch of print commands with breakpoints,
+	         it's possible for the frame stack to creep down.  If it creeps
+	         too far, give up and reset it to the top.  Normal use should
+	         not see this happen.
+	       */
+	      if ((unsigned int) (frame - 2) < (unsigned int) &gdbFrameStack)
+		{
+		  initializeRemcomErrorFrame ();
+		  frame = lastFrame;
+		}
+	      frame->previous = lastFrame;
+	      lastFrame = frame;
+	      frame = 0;	/* null so _return... will properly initialize it */
+	    }
+
+	  _returnFromException (frame);	/* this is a jump */
+
+	  break;
+
+	  /* kill the program */
+	case 'k':		/* do nothing */
+	  break;
+	}			/* switch */
+
+      /* reply to the request */
+      putpacket (remcomOutBuffer);
+    }
+}
+
+
+void
+initializeRemcomErrorFrame (void)
+{
+  lastFrame = ((Frame *) & gdbFrameStack[FRAMESIZE - 1]) - 1;
+  lastFrame->previous = lastFrame;
+}
+
+/* this function is used to set up exception handlers for tracing and 
+   breakpoints */
+void
+set_debug_traps ()
+{
+  extern void _debug_level7 ();
+  extern void remcomHandler ();
+  int exception;
+
+  initializeRemcomErrorFrame ();
+  stackPtr = &remcomStack[STACKSIZE / sizeof (int) - 1];
+
+  for (exception = 2; exception <= 23; exception++)
+    exceptionHandler (exception, _catchException);
+
+  /* level 7 interrupt              */
+  exceptionHandler (31, _debug_level7);
+
+  /* breakpoint exception (trap #1) */
+  exceptionHandler (33, _catchException);
+
+  /* This is a trap #8 instruction.  Apparently it is someone's software
+     convention for some sort of SIGFPE condition.  Whose?  How many
+     people are being screwed by having this code the way it is?
+     Is there a clean solution?  */
+  exceptionHandler (40, _catchException);
+
+  /* 48 to 54 are floating point coprocessor errors */
+  for (exception = 48; exception <= 54; exception++)
+    exceptionHandler (exception, _catchException);
+
+  if (oldExceptionHook != remcomHandler)
+    {
+      oldExceptionHook = exceptionHook;
+      exceptionHook = remcomHandler;
+    }
+
+  initialized = 1;
+
+}
+
+/* This function will generate a breakpoint exception.  It is used at the
+   beginning of a program to sync up with a debugger and can be used
+   otherwise as a quick means to stop program execution and "break" into
+   the debugger. */
+
+void
+breakpoint ()
+{
+  if (initialized)
+    BREAKPOINT ();
+}
diff --git a/gdb/stubs/sh-stub.c b/gdb/stubs/sh-stub.c
new file mode 100644
index 00000000000..76c98a5e8ad
--- /dev/null
+++ b/gdb/stubs/sh-stub.c
@@ -0,0 +1,1583 @@
+/* sh-stub.c -- debugging stub for the Renesas-SH.
+
+ NOTE!! This code has to be compiled with optimization, otherwise the 
+ function inlining which generates the exception handlers won't work.
+
+*/
+
+/*   This is originally based on an m68k software stub written by Glenn
+     Engel at HP, but has changed quite a bit. 
+
+     Modifications for the SH by Ben Lee and Steve Chamberlain
+
+*/
+
+/****************************************************************************
+
+		THIS SOFTWARE IS NOT COPYRIGHTED
+
+   HP offers the following for use in the public domain.  HP makes no
+   warranty with regard to the software or it's performance and the
+   user accepts the software "AS IS" with all faults.
+
+   HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
+   TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+
+****************************************************************************/
+
+
+/* Remote communication protocol.
+
+   A debug packet whose contents are <data>
+   is encapsulated for transmission in the form:
+
+	$ <data> # CSUM1 CSUM2
+
+	<data> must be ASCII alphanumeric and cannot include characters
+	'$' or '#'.  If <data> starts with two characters followed by
+	':', then the existing stubs interpret this as a sequence number.
+
+	CSUM1 and CSUM2 are ascii hex representation of an 8-bit 
+	checksum of <data>, the most significant nibble is sent first.
+	the hex digits 0-9,a-f are used.
+
+   Receiver responds with:
+
+	+	- if CSUM is correct and ready for next packet
+	-	- if CSUM is incorrect
+
+   <data> is as follows:
+   All values are encoded in ascii hex digits.
+
+	Request		Packet
+
+	read registers  g
+	reply		XX....X		Each byte of register data
+					is described by two hex digits.
+					Registers are in the internal order
+					for GDB, and the bytes in a register
+					are in the same order the machine uses.
+			or ENN		for an error.
+
+	write regs	GXX..XX		Each byte of register data
+					is described by two hex digits.
+	reply		OK		for success
+			ENN		for an error
+
+        write reg	Pn...=r...	Write register n... with value r...,
+					which contains two hex digits for each
+					byte in the register (target byte
+					order).
+	reply		OK		for success
+			ENN		for an error
+	(not supported by all stubs).
+
+	read mem	mAA..AA,LLLL	AA..AA is address, LLLL is length.
+	reply		XX..XX		XX..XX is mem contents
+					Can be fewer bytes than requested
+					if able to read only part of the data.
+			or ENN		NN is errno
+
+	write mem	MAA..AA,LLLL:XX..XX
+					AA..AA is address,
+					LLLL is number of bytes,
+					XX..XX is data
+	reply		OK		for success
+			ENN		for an error (this includes the case
+					where only part of the data was
+					written).
+
+	cont		cAA..AA		AA..AA is address to resume
+					If AA..AA is omitted,
+					resume at same address.
+
+	step		sAA..AA		AA..AA is address to resume
+					If AA..AA is omitted,
+					resume at same address.
+
+	last signal     ?               Reply the current reason for stopping.
+                                        This is the same reply as is generated
+					for step or cont : SAA where AA is the
+					signal number.
+
+	There is no immediate reply to step or cont.
+	The reply comes when the machine stops.
+	It is		SAA		AA is the "signal number"
+
+	or...		TAAn...:r...;n:r...;n...:r...;
+					AA = signal number
+					n... = register number
+					r... = register contents
+	or...		WAA		The process exited, and AA is
+					the exit status.  This is only
+					applicable for certains sorts of
+					targets.
+	kill request	k
+
+	toggle debug	d		toggle debug flag (see 386 & 68k stubs)
+	reset		r		reset -- see sparc stub.
+	reserved	<other>		On other requests, the stub should
+					ignore the request and send an empty
+					response ($#<checksum>).  This way
+					we can extend the protocol and GDB
+					can tell whether the stub it is
+					talking to uses the old or the new.
+	search		tAA:PP,MM	Search backwards starting at address
+					AA for a match with pattern PP and
+					mask MM.  PP and MM are 4 bytes.
+					Not supported by all stubs.
+
+	general query	qXXXX		Request info about XXXX.
+	general set	QXXXX=yyyy	Set value of XXXX to yyyy.
+	query sect offs	qOffsets	Get section offsets.  Reply is
+					Text=xxx;Data=yyy;Bss=zzz
+	console output	Otext		Send text to stdout.  Only comes from
+					remote target.
+
+	Responses can be run-length encoded to save space.  A '*' means that
+	the next character is an ASCII encoding giving a repeat count which
+	stands for that many repititions of the character preceding the '*'.
+	The encoding is n+29, yielding a printable character where n >=3 
+	(which is where rle starts to win).  Don't use an n > 126. 
+
+	So 
+	"0* " means the same as "0000".  */
+
+#include <string.h>
+#include <setjmp.h>
+
+/* Renesas SH architecture instruction encoding masks */
+
+#define COND_BR_MASK   0xff00
+#define UCOND_DBR_MASK 0xe000
+#define UCOND_RBR_MASK 0xf0df
+#define TRAPA_MASK     0xff00
+
+#define COND_DISP      0x00ff
+#define UCOND_DISP     0x0fff
+#define UCOND_REG      0x0f00
+
+/* Renesas SH instruction opcodes */
+
+#define BF_INSTR       0x8b00
+#define BT_INSTR       0x8900
+#define BRA_INSTR      0xa000
+#define BSR_INSTR      0xb000
+#define JMP_INSTR      0x402b
+#define JSR_INSTR      0x400b
+#define RTS_INSTR      0x000b
+#define RTE_INSTR      0x002b
+#define TRAPA_INSTR    0xc300
+#define SSTEP_INSTR    0xc3ff
+
+/* Renesas SH processor register masks */
+
+#define T_BIT_MASK     0x0001
+
+/*
+ * BUFMAX defines the maximum number of characters in inbound/outbound
+ * buffers. At least NUMREGBYTES*2 are needed for register packets.
+ */
+#define BUFMAX 1024
+
+/*
+ * Number of bytes for registers
+ */
+#define NUMREGBYTES 112		/* 92 */
+
+/*
+ * typedef
+ */
+typedef void (*Function) ();
+
+/*
+ * Forward declarations
+ */
+
+static int hex (char);
+static char *mem2hex (char *, char *, int);
+static char *hex2mem (char *, char *, int);
+static int hexToInt (char **, int *);
+static unsigned char *getpacket (void);
+static void putpacket (char *);
+static void handle_buserror (void);
+static int computeSignal (int exceptionVector);
+static void handle_exception (int exceptionVector);
+void init_serial();
+
+void putDebugChar (char);
+char getDebugChar (void);
+
+/* These are in the file but in asm statements so the compiler can't see them */
+void catch_exception_4 (void);
+void catch_exception_6 (void);
+void catch_exception_9 (void);
+void catch_exception_10 (void);
+void catch_exception_11 (void);
+void catch_exception_32 (void);
+void catch_exception_33 (void);
+void catch_exception_255 (void);
+
+
+
+#define catch_exception_random catch_exception_255 /* Treat all odd ones like 255 */
+
+void breakpoint (void);
+
+
+#define init_stack_size 8*1024  /* if you change this you should also modify BINIT */
+#define stub_stack_size 8*1024
+
+int init_stack[init_stack_size] __attribute__ ((section ("stack"))) = {0};
+int stub_stack[stub_stack_size] __attribute__ ((section ("stack"))) = {0};
+
+
+void INIT ();
+void BINIT ();
+
+#define CPU_BUS_ERROR_VEC  9
+#define DMA_BUS_ERROR_VEC 10
+#define NMI_VEC           11
+#define INVALID_INSN_VEC   4
+#define INVALID_SLOT_VEC   6
+#define TRAP_VEC          32
+#define IO_VEC            33
+#define USER_VEC         255
+
+
+
+char in_nmi;   /* Set when handling an NMI, so we don't reenter */
+int dofault;  /* Non zero, bus errors will raise exception */
+
+int *stub_sp;
+
+/* debug > 0 prints ill-formed commands in valid packets & checksum errors */
+int remote_debug;
+
+/* jump buffer used for setjmp/longjmp */
+jmp_buf remcomEnv;
+
+enum regnames
+  {
+    R0, R1, R2, R3, R4, R5, R6, R7,
+    R8, R9, R10, R11, R12, R13, R14,
+    R15, PC, PR, GBR, VBR, MACH, MACL, SR,
+    TICKS, STALLS, CYCLES, INSTS, PLR
+  };
+
+typedef struct
+  {
+    short *memAddr;
+    short oldInstr;
+  }
+stepData;
+
+int registers[NUMREGBYTES / 4];
+stepData instrBuffer;
+char stepped;
+static const char hexchars[] = "0123456789abcdef";
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
+
+char highhex(int  x)
+{
+  return hexchars[(x >> 4) & 0xf];
+}
+
+char lowhex(int  x)
+{
+  return hexchars[x & 0xf];
+}
+
+/*
+ * Assembly macros
+ */
+
+#define BREAKPOINT()   asm("trapa	#0x20"::);
+
+
+/*
+ * Routines to handle hex data
+ */
+
+static int
+hex (char ch)
+{
+  if ((ch >= 'a') && (ch <= 'f'))
+    return (ch - 'a' + 10);
+  if ((ch >= '0') && (ch <= '9'))
+    return (ch - '0');
+  if ((ch >= 'A') && (ch <= 'F'))
+    return (ch - 'A' + 10);
+  return (-1);
+}
+
+/* convert the memory, pointed to by mem into hex, placing result in buf */
+/* return a pointer to the last char put in buf (null) */
+static char *
+mem2hex (char *mem, char *buf, int count)
+{
+  int i;
+  int ch;
+  for (i = 0; i < count; i++)
+    {
+      ch = *mem++;
+      *buf++ = highhex (ch);
+      *buf++ = lowhex (ch);
+    }
+  *buf = 0;
+  return (buf);
+}
+
+/* convert the hex array pointed to by buf into binary, to be placed in mem */
+/* return a pointer to the character after the last byte written */
+
+static char *
+hex2mem (char *buf, char *mem, int count)
+{
+  int i;
+  unsigned char ch;
+  for (i = 0; i < count; i++)
+    {
+      ch = hex (*buf++) << 4;
+      ch = ch + hex (*buf++);
+      *mem++ = ch;
+    }
+  return (mem);
+}
+
+/**********************************************/
+/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */
+/* RETURN NUMBER OF CHARS PROCESSED           */
+/**********************************************/
+static int
+hexToInt (char **ptr, int *intValue)
+{
+  int numChars = 0;
+  int hexValue;
+
+  *intValue = 0;
+
+  while (**ptr)
+    {
+      hexValue = hex (**ptr);
+      if (hexValue >= 0)
+	{
+	  *intValue = (*intValue << 4) | hexValue;
+	  numChars++;
+	}
+      else
+	break;
+
+      (*ptr)++;
+    }
+
+  return (numChars);
+}
+
+/*
+ * Routines to get and put packets
+ */
+
+/* scan for the sequence $<data>#<checksum>     */
+
+char *
+getpacket (void)
+{
+  unsigned char *buffer = &remcomInBuffer[0];
+  unsigned char checksum;
+  unsigned char xmitcsum;
+  int count;
+  char ch;
+
+  while (1)
+    {
+      /* wait around for the start character, ignore all other characters */
+      while ((ch = getDebugChar ()) != '$')
+	;
+
+retry:
+      checksum = 0;
+      xmitcsum = -1;
+      count = 0;
+
+      /* now, read until a # or end of buffer is found */
+      while (count < BUFMAX - 1)
+	{
+	  ch = getDebugChar ();
+          if (ch == '$')
+            goto retry;
+	  if (ch == '#')
+	    break;
+	  checksum = checksum + ch;
+	  buffer[count] = ch;
+	  count = count + 1;
+	}
+      buffer[count] = 0;
+
+      if (ch == '#')
+	{
+ 	  ch = getDebugChar ();
+ 	  xmitcsum = hex (ch) << 4;
+ 	  ch = getDebugChar ();
+ 	  xmitcsum += hex (ch);
+
+	  if (checksum != xmitcsum)
+	    {
+	      putDebugChar ('-');	/* failed checksum */
+	    }
+	  else
+	    {
+	      putDebugChar ('+');	/* successful transfer */
+
+	      /* if a sequence char is present, reply the sequence ID */
+	      if (buffer[2] == ':')
+		{
+		  putDebugChar (buffer[0]);
+		  putDebugChar (buffer[1]);
+
+ 		  return &buffer[3];
+		}
+
+	      return &buffer[0];
+	    }
+	}
+    }
+}
+
+
+/* send the packet in buffer. */
+
+static void
+putpacket (char *buffer)
+{
+  int checksum;
+  int count;
+
+  /*  $<packet info>#<checksum>. */
+  do
+    {
+      char *src = buffer;
+      putDebugChar ('$');
+      checksum = 0;
+
+      while (*src)
+	{
+	  int runlen;
+
+	  /* Do run length encoding */
+	  for (runlen = 0; runlen < 100; runlen ++) 
+	    {
+	      if (src[0] != src[runlen]) 
+		{
+		  if (runlen > 3) 
+		    {
+		      int encode;
+		      /* Got a useful amount */
+		      putDebugChar (*src);
+		      checksum += *src;
+		      putDebugChar ('*');
+		      checksum += '*';
+		      checksum += (encode = runlen + ' ' - 4);
+		      putDebugChar (encode);
+		      src += runlen;
+		    }
+		  else
+		    {
+		      putDebugChar (*src);
+		      checksum += *src;
+		      src++;
+		    }
+		  break;
+		}
+	    }
+	}
+
+
+      putDebugChar ('#');
+      putDebugChar (highhex(checksum));
+      putDebugChar (lowhex(checksum));
+    }
+  while  (getDebugChar() != '+');
+}
+
+
+/* a bus error has occurred, perform a longjmp
+   to return execution and allow handling of the error */
+
+void
+handle_buserror (void)
+{
+  longjmp (remcomEnv, 1);
+}
+
+/*
+ * this function takes the SH-1 exception number and attempts to
+ * translate this number into a unix compatible signal value
+ */
+static int
+computeSignal (int exceptionVector)
+{
+  int sigval;
+  switch (exceptionVector)
+    {
+    case INVALID_INSN_VEC:
+      sigval = 4;
+      break;			
+    case INVALID_SLOT_VEC:
+      sigval = 4;
+      break;			
+    case CPU_BUS_ERROR_VEC:
+      sigval = 10;
+      break;			
+    case DMA_BUS_ERROR_VEC:
+      sigval = 10;
+      break;	
+    case NMI_VEC:
+      sigval = 2;
+      break;	
+
+    case TRAP_VEC:
+    case USER_VEC:
+      sigval = 5;
+      break;
+
+    default:
+      sigval = 7;		/* "software generated"*/
+      break;
+    }
+  return (sigval);
+}
+
+void
+doSStep (void)
+{
+  short *instrMem;
+  int displacement;
+  int reg;
+  unsigned short opcode;
+
+  instrMem = (short *) registers[PC];
+
+  opcode = *instrMem;
+  stepped = 1;
+
+  if ((opcode & COND_BR_MASK) == BT_INSTR)
+    {
+      if (registers[SR] & T_BIT_MASK)
+	{
+	  displacement = (opcode & COND_DISP) << 1;
+	  if (displacement & 0x80)
+	    displacement |= 0xffffff00;
+	  /*
+		   * Remember PC points to second instr.
+		   * after PC of branch ... so add 4
+		   */
+	  instrMem = (short *) (registers[PC] + displacement + 4);
+	}
+      else
+	instrMem += 1;
+    }
+  else if ((opcode & COND_BR_MASK) == BF_INSTR)
+    {
+      if (registers[SR] & T_BIT_MASK)
+	instrMem += 1;
+      else
+	{
+	  displacement = (opcode & COND_DISP) << 1;
+	  if (displacement & 0x80)
+	    displacement |= 0xffffff00;
+	  /*
+		   * Remember PC points to second instr.
+		   * after PC of branch ... so add 4
+		   */
+	  instrMem = (short *) (registers[PC] + displacement + 4);
+	}
+    }
+  else if ((opcode & UCOND_DBR_MASK) == BRA_INSTR)
+    {
+      displacement = (opcode & UCOND_DISP) << 1;
+      if (displacement & 0x0800)
+	displacement |= 0xfffff000;
+
+      /*
+	   * Remember PC points to second instr.
+	   * after PC of branch ... so add 4
+	   */
+      instrMem = (short *) (registers[PC] + displacement + 4);
+    }
+  else if ((opcode & UCOND_RBR_MASK) == JSR_INSTR)
+    {
+      reg = (char) ((opcode & UCOND_REG) >> 8);
+
+      instrMem = (short *) registers[reg];
+    }
+  else if (opcode == RTS_INSTR)
+    instrMem = (short *) registers[PR];
+  else if (opcode == RTE_INSTR)
+    instrMem = (short *) registers[15];
+  else if ((opcode & TRAPA_MASK) == TRAPA_INSTR)
+    instrMem = (short *) ((opcode & ~TRAPA_MASK) << 2);
+  else
+    instrMem += 1;
+
+  instrBuffer.memAddr = instrMem;
+  instrBuffer.oldInstr = *instrMem;
+  *instrMem = SSTEP_INSTR;
+}
+
+
+/* Undo the effect of a previous doSStep.  If we single stepped,
+   restore the old instruction. */
+
+void
+undoSStep (void)
+{
+  if (stepped)
+    {  short *instrMem;
+      instrMem = instrBuffer.memAddr;
+      *instrMem = instrBuffer.oldInstr;
+    }
+  stepped = 0;
+}
+
+/*
+This function does all exception handling.  It only does two things -
+it figures out why it was called and tells gdb, and then it reacts
+to gdb's requests.
+
+When in the monitor mode we talk a human on the serial line rather than gdb.
+
+*/
+
+
+void
+gdb_handle_exception (int exceptionVector)
+{
+  int sigval, stepping;
+  int addr, length;
+  char *ptr;
+
+  /* reply to host that an exception has occurred */
+  sigval = computeSignal (exceptionVector);
+  remcomOutBuffer[0] = 'S';
+  remcomOutBuffer[1] = highhex(sigval);
+  remcomOutBuffer[2] = lowhex (sigval);
+  remcomOutBuffer[3] = 0;
+
+  putpacket (remcomOutBuffer);
+
+  /*
+   * exception 255 indicates a software trap
+   * inserted in place of code ... so back up
+   * PC by one instruction, since this instruction
+   * will later be replaced by its original one!
+   */
+  if (exceptionVector == 0xff
+      || exceptionVector == 0x20)
+    registers[PC] -= 2;
+
+  /*
+   * Do the thangs needed to undo
+   * any stepping we may have done!
+   */
+  undoSStep ();
+
+  stepping = 0;
+
+  while (1)
+    {
+      remcomOutBuffer[0] = 0;
+      ptr = getpacket ();
+
+      switch (*ptr++)
+	{
+	case '?':
+	  remcomOutBuffer[0] = 'S';
+	  remcomOutBuffer[1] = highhex (sigval);
+	  remcomOutBuffer[2] = lowhex (sigval);
+	  remcomOutBuffer[3] = 0;
+	  break;
+	case 'd':
+	  remote_debug = !(remote_debug);	/* toggle debug flag */
+	  break;
+	case 'g':		/* return the value of the CPU registers */
+	  mem2hex ((char *) registers, remcomOutBuffer, NUMREGBYTES);
+	  break;
+	case 'G':		/* set the value of the CPU registers - return OK */
+	  hex2mem (ptr, (char *) registers, NUMREGBYTES);
+	  strcpy (remcomOutBuffer, "OK");
+	  break;
+
+	  /* mAA..AA,LLLL  Read LLLL bytes at address AA..AA */
+	case 'm':
+	  if (setjmp (remcomEnv) == 0)
+	    {
+	      dofault = 0;
+	      /* TRY, TO READ %x,%x.  IF SUCCEED, SET PTR = 0 */
+	      if (hexToInt (&ptr, &addr))
+		if (*(ptr++) == ',')
+		  if (hexToInt (&ptr, &length))
+		    {
+		      ptr = 0;
+		      mem2hex ((char *) addr, remcomOutBuffer, length);
+		    }
+	      if (ptr)
+		strcpy (remcomOutBuffer, "E01");
+	    }
+	  else
+	    strcpy (remcomOutBuffer, "E03");
+
+	  /* restore handler for bus error */
+	  dofault = 1;
+	  break;
+
+	  /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
+	case 'M':
+	  if (setjmp (remcomEnv) == 0)
+	    {
+	      dofault = 0;
+
+	      /* TRY, TO READ '%x,%x:'.  IF SUCCEED, SET PTR = 0 */
+	      if (hexToInt (&ptr, &addr))
+		if (*(ptr++) == ',')
+		  if (hexToInt (&ptr, &length))
+		    if (*(ptr++) == ':')
+		      {
+			hex2mem (ptr, (char *) addr, length);
+			ptr = 0;
+			strcpy (remcomOutBuffer, "OK");
+		      }
+	      if (ptr)
+		strcpy (remcomOutBuffer, "E02");
+	    }
+	  else
+	    strcpy (remcomOutBuffer, "E03");
+
+	  /* restore handler for bus error */
+	  dofault = 1;
+	  break;
+
+	  /* cAA..AA    Continue at address AA..AA(optional) */
+	  /* sAA..AA   Step one instruction from AA..AA(optional) */
+	case 's':
+	  stepping = 1;
+	case 'c':
+	  {
+	    /* tRY, to read optional parameter, pc unchanged if no parm */
+	    if (hexToInt (&ptr, &addr))
+	      registers[PC] = addr;
+
+	    if (stepping)
+	      doSStep ();
+	  }
+	  return;
+	  break;
+
+	  /* kill the program */
+	case 'k':		/* do nothing */
+	  break;
+	}			/* switch */
+
+      /* reply to the request */
+      putpacket (remcomOutBuffer);
+    }
+}
+
+
+#define GDBCOOKIE 0x5ac 
+static int ingdbmode;
+/* We've had an exception - choose to go into the monitor or
+   the gdb stub */
+void handle_exception(int exceptionVector)
+{
+#ifdef MONITOR
+    if (ingdbmode != GDBCOOKIE)
+      monitor_handle_exception (exceptionVector);
+    else 
+#endif
+      gdb_handle_exception (exceptionVector);
+
+}
+
+void
+gdb_mode (void)
+{
+  ingdbmode = GDBCOOKIE;
+  breakpoint();
+}
+/* This function will generate a breakpoint exception.  It is used at the
+   beginning of a program to sync up with a debugger and can be used
+   otherwise as a quick means to stop program execution and "break" into
+   the debugger. */
+
+void
+breakpoint (void)
+{
+      BREAKPOINT ();
+}
+
+/**** Processor-specific routines start here ****/
+/**** Processor-specific routines start here ****/
+/**** Processor-specific routines start here ****/
+
+/* Note:
+
+   The Renesas SH family uses two exception architectures:
+
+   SH1 & SH2:
+
+       These processors utilize an exception vector table.
+       Exceptions are vectored to the address stored at VBR + (exception_num * 4)
+
+  SH3, SH3E, & SH4:
+
+       These processors have fixed entry points relative to the VBR for
+       various exception classes.
+*/
+
+#if defined(__sh1__) || defined(__sh2__)
+
+/* SH1/SH2 exception vector table format */
+
+typedef struct
+  {
+    void (*func_cold) ();
+    int *stack_cold;
+    void (*func_warm) ();
+    int *stack_warm;
+    void (*(handler[256 - 4])) ();
+  }
+vec_type;
+
+/* vectable is the SH1/SH2 vector table. It must be at address 0
+   or wherever your vbr points. */
+
+const vec_type vectable =
+{ 
+  &BINIT,			/* 0: Power-on reset PC */
+  init_stack + init_stack_size, /* 1: Power-on reset SP */
+  &BINIT,			/* 2: Manual reset PC */
+  init_stack + init_stack_size, /* 3: Manual reset SP */
+{
+  &catch_exception_4,		/* 4: General invalid instruction */
+  &catch_exception_random,	/* 5: Reserved for system */
+  &catch_exception_6,		/* 6: Invalid slot instruction */
+  &catch_exception_random,	/* 7: Reserved for system */
+  &catch_exception_random,	/* 8: Reserved for system */
+  &catch_exception_9,		/* 9: CPU bus error */
+  &catch_exception_10,		/* 10: DMA bus error */
+  &catch_exception_11,		/* 11: NMI */
+  &catch_exception_random,	/* 12: User break */
+  &catch_exception_random,	/* 13: Reserved for system */
+  &catch_exception_random,	/* 14: Reserved for system */
+  &catch_exception_random,	/* 15: Reserved for system */
+  &catch_exception_random,	/* 16: Reserved for system */
+  &catch_exception_random,	/* 17: Reserved for system */
+  &catch_exception_random,	/* 18: Reserved for system */
+  &catch_exception_random,	/* 19: Reserved for system */
+  &catch_exception_random,	/* 20: Reserved for system */
+  &catch_exception_random,	/* 21: Reserved for system */
+  &catch_exception_random,	/* 22: Reserved for system */
+  &catch_exception_random,	/* 23: Reserved for system */
+  &catch_exception_random,	/* 24: Reserved for system */
+  &catch_exception_random,	/* 25: Reserved for system */
+  &catch_exception_random,	/* 26: Reserved for system */
+  &catch_exception_random,	/* 27: Reserved for system */
+  &catch_exception_random,	/* 28: Reserved for system */
+  &catch_exception_random,	/* 29: Reserved for system */
+  &catch_exception_random,	/* 30: Reserved for system */
+  &catch_exception_random,	/* 31: Reserved for system */
+  &catch_exception_32,		/* 32: Trap instr (user vectors) */
+  &catch_exception_33,		/* 33: Trap instr (user vectors) */
+  &catch_exception_random,	/* 34: Trap instr (user vectors) */
+  &catch_exception_random,	/* 35: Trap instr (user vectors) */
+  &catch_exception_random,	/* 36: Trap instr (user vectors) */
+  &catch_exception_random,	/* 37: Trap instr (user vectors) */
+  &catch_exception_random,	/* 38: Trap instr (user vectors) */
+  &catch_exception_random,	/* 39: Trap instr (user vectors) */
+  &catch_exception_random,	/* 40: Trap instr (user vectors) */
+  &catch_exception_random,	/* 41: Trap instr (user vectors) */
+  &catch_exception_random,	/* 42: Trap instr (user vectors) */
+  &catch_exception_random,	/* 43: Trap instr (user vectors) */
+  &catch_exception_random,	/* 44: Trap instr (user vectors) */
+  &catch_exception_random,	/* 45: Trap instr (user vectors) */
+  &catch_exception_random,	/* 46: Trap instr (user vectors) */
+  &catch_exception_random,	/* 47: Trap instr (user vectors) */
+  &catch_exception_random,	/* 48: Trap instr (user vectors) */
+  &catch_exception_random,	/* 49: Trap instr (user vectors) */
+  &catch_exception_random,	/* 50: Trap instr (user vectors) */
+  &catch_exception_random,	/* 51: Trap instr (user vectors) */
+  &catch_exception_random,	/* 52: Trap instr (user vectors) */
+  &catch_exception_random,	/* 53: Trap instr (user vectors) */
+  &catch_exception_random,	/* 54: Trap instr (user vectors) */
+  &catch_exception_random,	/* 55: Trap instr (user vectors) */
+  &catch_exception_random,	/* 56: Trap instr (user vectors) */
+  &catch_exception_random,	/* 57: Trap instr (user vectors) */
+  &catch_exception_random,	/* 58: Trap instr (user vectors) */
+  &catch_exception_random,	/* 59: Trap instr (user vectors) */
+  &catch_exception_random,	/* 60: Trap instr (user vectors) */
+  &catch_exception_random,	/* 61: Trap instr (user vectors) */
+  &catch_exception_random,	/* 62: Trap instr (user vectors) */
+  &catch_exception_random,	/* 63: Trap instr (user vectors) */
+  &catch_exception_random,	/* 64: IRQ0 */
+  &catch_exception_random,	/* 65: IRQ1 */
+  &catch_exception_random,	/* 66: IRQ2 */
+  &catch_exception_random,	/* 67: IRQ3 */
+  &catch_exception_random,	/* 68: IRQ4 */
+  &catch_exception_random,	/* 69: IRQ5 */
+  &catch_exception_random,	/* 70: IRQ6 */
+  &catch_exception_random,	/* 71: IRQ7 */
+  &catch_exception_random,
+  &catch_exception_random,
+  &catch_exception_random,
+  &catch_exception_random,
+  &catch_exception_random,
+  &catch_exception_random,
+  &catch_exception_random,
+  &catch_exception_random,
+  &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_random,
+     &catch_exception_255}};
+
+#define BCR  (*(volatile short *)(0x05FFFFA0)) /* Bus control register */
+#define BAS  (0x800)				/* Byte access select */
+#define WCR1 (*(volatile short *)(0x05ffffA2)) /* Wait state control register */
+
+asm ("_BINIT: mov.l  L1,r15");
+asm ("bra _INIT");
+asm ("nop");
+asm ("L1: .long _init_stack + 8*1024*4");
+void
+INIT (void)
+{
+  /* First turn on the ram */
+  WCR1  = 0;    /* Never sample wait */
+  BCR = BAS;    /* use lowbyte/high byte */
+
+  init_serial();
+
+#ifdef MONITOR
+  reset_hook ();
+#endif
+
+
+  in_nmi = 0;
+  dofault = 1;
+  stepped = 0;
+
+  stub_sp = stub_stack + stub_stack_size;
+  breakpoint ();
+
+  while (1)
+    ;
+}
+
+
+static void sr()
+{
+
+
+  /* Calling Reset does the same as pressing the button */
+  asm (".global _Reset
+        .global _WarmReset
+_Reset:
+_WarmReset:
+         mov.l L_sp,r15
+         bra   _INIT
+         nop
+         .align 2
+L_sp:    .long _init_stack + 8000");
+
+  asm("saveRegisters:
+	mov.l	@(L_reg, pc), r0
+	mov.l	@r15+, r1				! pop R0
+	mov.l	r2, @(0x08, r0)				! save R2
+	mov.l	r1, @r0					! save R0
+	mov.l	@r15+, r1				! pop R1
+	mov.l	r3, @(0x0c, r0)				! save R3
+	mov.l	r1, @(0x04, r0)				! save R1
+	mov.l	r4, @(0x10, r0)				! save R4
+	mov.l	r5, @(0x14, r0)				! save R5
+	mov.l	r6, @(0x18, r0)				! save R6
+	mov.l	r7, @(0x1c, r0)				! save R7
+	mov.l	r8, @(0x20, r0)				! save R8
+	mov.l	r9, @(0x24, r0)				! save R9
+	mov.l	r10, @(0x28, r0)			! save R10
+	mov.l	r11, @(0x2c, r0)			! save R11
+	mov.l	r12, @(0x30, r0)			! save R12
+	mov.l	r13, @(0x34, r0)			! save R13
+	mov.l	r14, @(0x38, r0)			! save R14
+	mov.l	@r15+, r4				! save arg to handleException
+	add	#8, r15					! hide PC/SR values on stack
+	mov.l	r15, @(0x3c, r0)			! save R15
+	add	#-8, r15				! save still needs old SP value
+	add	#92, r0					! readjust register pointer
+	mov	r15, r2
+	add	#4, r2
+	mov.l	@r2, r2					! R2 has SR
+	mov.l	@r15, r1				! R1 has PC
+	mov.l	r2, @-r0				! save SR
+	sts.l	macl, @-r0				! save MACL
+	sts.l	mach, @-r0				! save MACH
+	stc.l	vbr, @-r0				! save VBR
+	stc.l	gbr, @-r0				! save GBR
+	sts.l	pr, @-r0				! save PR
+	mov.l	@(L_stubstack, pc), r2
+	mov.l	@(L_hdl_except, pc), r3
+	mov.l	@r2, r15
+	jsr	@r3
+	mov.l	r1, @-r0				! save PC
+	mov.l	@(L_stubstack, pc), r0
+	mov.l	@(L_reg, pc), r1
+	bra	restoreRegisters
+	mov.l	r15, @r0				! save __stub_stack
+	
+	.align 2
+L_reg:
+	.long	_registers
+L_stubstack:
+	.long	_stub_sp
+L_hdl_except:
+	.long	_handle_exception");
+
+}
+
+static void rr()
+{
+asm("
+	.align 2	
+        .global _resume
+_resume:
+	mov	r4,r1
+restoreRegisters:
+	add	#8, r1						! skip to R2
+	mov.l	@r1+, r2					! restore R2
+	mov.l	@r1+, r3					! restore R3
+	mov.l	@r1+, r4					! restore R4
+	mov.l	@r1+, r5					! restore R5
+	mov.l	@r1+, r6					! restore R6
+	mov.l	@r1+, r7					! restore R7
+	mov.l	@r1+, r8					! restore R8
+	mov.l	@r1+, r9					! restore R9
+	mov.l	@r1+, r10					! restore R10
+	mov.l	@r1+, r11					! restore R11
+	mov.l	@r1+, r12					! restore R12
+	mov.l	@r1+, r13					! restore R13
+	mov.l	@r1+, r14					! restore R14
+	mov.l	@r1+, r15					! restore programs stack
+	mov.l	@r1+, r0
+	add	#-8, r15					! uncover PC/SR on stack 
+	mov.l	r0, @r15					! restore PC onto stack
+	lds.l	@r1+, pr					! restore PR
+	ldc.l	@r1+, gbr					! restore GBR		
+	ldc.l	@r1+, vbr					! restore VBR
+	lds.l	@r1+, mach					! restore MACH
+	lds.l	@r1+, macl					! restore MACL
+	mov.l	@r1, r0	
+	add	#-88, r1					! readjust reg pointer to R1
+	mov.l	r0, @(4, r15)					! restore SR onto stack+4
+	mov.l	r2, @-r15
+	mov.l	L_in_nmi, r0
+	mov		#0, r2
+	mov.b	r2, @r0
+	mov.l	@r15+, r2
+	mov.l	@r1+, r0					! restore R0
+	rte
+	mov.l	@r1, r1						! restore R1
+
+");
+}
+
+
+static __inline__ void code_for_catch_exception(int n) 
+{
+  asm("		.globl	_catch_exception_%O0" : : "i" (n) 				); 
+  asm("	_catch_exception_%O0:" :: "i" (n)      						);
+
+  asm("		add	#-4, r15 				! reserve spot on stack ");
+  asm("		mov.l	r1, @-r15				! push R1		");
+
+  if (n == NMI_VEC) 
+    {
+      /* Special case for NMI - make sure that they don't nest */
+      asm("	mov.l	r0, @-r15					! push R0");
+      asm("	mov.l	L_in_nmi, r0");
+      asm("	tas.b	@r0						! Fend off against addtnl NMIs");
+      asm("	bt		noNMI");
+      asm("	mov.l	@r15+, r0");
+      asm("	mov.l	@r15+, r1");
+      asm("	add		#4, r15");
+      asm("	rte");
+      asm("	nop");
+      asm(".align 2");
+      asm("L_in_nmi: .long	_in_nmi");
+      asm("noNMI:");
+    }
+  else
+    {
+
+      if (n == CPU_BUS_ERROR_VEC)
+	{
+	  /* Exception 9 (bus errors) are disasbleable - so that you
+	     can probe memory and get zero instead of a fault.
+	     Because the vector table may be in ROM we don't revector
+	     the interrupt like all the other stubs, we check in here
+	     */
+	  asm("mov.l	L_dofault,r1");
+	  asm("mov.l	@r1,r1");
+	  asm("tst	r1,r1");
+	  asm("bf	faultaway");
+	  asm("bsr	_handle_buserror");
+	  asm(".align	2");
+	  asm("L_dofault: .long _dofault");
+	  asm("faultaway:");
+	}
+      asm("		mov	#15<<4, r1							");
+      asm("		ldc	r1, sr					! disable interrupts	");
+      asm("		mov.l	r0, @-r15				! push R0		");
+    }
+
+  /* Prepare for saving context, we've already pushed r0 and r1, stick exception number
+     into the frame */
+  asm("		mov	r15, r0								");
+  asm("		add	#8, r0								");
+  asm("		mov	%0,r1" :: "i" (n)        					);
+  asm("		extu.b  r1,r1								");
+  asm("		bra	saveRegisters				! save register values	");
+  asm("		mov.l	r1, @r0					! save exception # 	");
+}
+
+
+static  void
+exceptions (void)
+{
+  code_for_catch_exception (CPU_BUS_ERROR_VEC);
+  code_for_catch_exception (DMA_BUS_ERROR_VEC);
+  code_for_catch_exception (INVALID_INSN_VEC);
+  code_for_catch_exception (INVALID_SLOT_VEC);
+  code_for_catch_exception (NMI_VEC);
+  code_for_catch_exception (TRAP_VEC);
+  code_for_catch_exception (USER_VEC);
+  code_for_catch_exception (IO_VEC);
+}
+
+
+
+
+
+
+/* Support for Serial I/O using on chip uart */
+
+#define SMR0 (*(volatile char *)(0x05FFFEC0)) /* Channel 0  serial mode register */
+#define BRR0 (*(volatile char *)(0x05FFFEC1)) /* Channel 0  bit rate register */
+#define SCR0 (*(volatile char *)(0x05FFFEC2)) /* Channel 0  serial control register */
+#define TDR0 (*(volatile char *)(0x05FFFEC3)) /* Channel 0  transmit data register */
+#define SSR0 (*(volatile char *)(0x05FFFEC4)) /* Channel 0  serial status register */
+#define RDR0 (*(volatile char *)(0x05FFFEC5)) /* Channel 0  receive data register */
+
+#define SMR1 (*(volatile char *)(0x05FFFEC8)) /* Channel 1  serial mode register */
+#define BRR1 (*(volatile char *)(0x05FFFEC9)) /* Channel 1  bit rate register */
+#define SCR1 (*(volatile char *)(0x05FFFECA)) /* Channel 1  serial control register */
+#define TDR1 (*(volatile char *)(0x05FFFECB)) /* Channel 1  transmit data register */
+#define SSR1 (*(volatile char *)(0x05FFFECC)) /* Channel 1  serial status register */
+#define RDR1 (*(volatile char *)(0x05FFFECD)) /* Channel 1  receive data register */
+
+/*
+ * Serial mode register bits
+ */
+
+#define SYNC_MODE 		0x80
+#define SEVEN_BIT_DATA 		0x40
+#define PARITY_ON		0x20
+#define ODD_PARITY		0x10
+#define STOP_BITS_2		0x08
+#define ENABLE_MULTIP		0x04
+#define PHI_64			0x03
+#define PHI_16			0x02
+#define PHI_4			0x01
+
+/*
+ * Serial control register bits
+ */
+#define SCI_TIE				0x80	/* Transmit interrupt enable */
+#define SCI_RIE				0x40	/* Receive interrupt enable */
+#define SCI_TE				0x20	/* Transmit enable */
+#define SCI_RE				0x10	/* Receive enable */
+#define SCI_MPIE			0x08	/* Multiprocessor interrupt enable */
+#define SCI_TEIE			0x04	/* Transmit end interrupt enable */
+#define SCI_CKE1			0x02	/* Clock enable 1 */
+#define SCI_CKE0			0x01	/* Clock enable 0 */
+
+/*
+ * Serial status register bits
+ */
+#define SCI_TDRE			0x80	/* Transmit data register empty */
+#define SCI_RDRF			0x40	/* Receive data register full */
+#define SCI_ORER			0x20	/* Overrun error */
+#define SCI_FER				0x10	/* Framing error */
+#define SCI_PER				0x08	/* Parity error */
+#define SCI_TEND			0x04	/* Transmit end */
+#define SCI_MPB				0x02	/* Multiprocessor bit */
+#define SCI_MPBT			0x01	/* Multiprocessor bit transfer */
+
+
+/*
+ * Port B IO Register (PBIOR)
+ */
+#define	PBIOR 		(*(volatile char *)(0x05FFFFC6))
+#define	PB15IOR 	0x8000
+#define	PB14IOR 	0x4000
+#define	PB13IOR 	0x2000
+#define	PB12IOR 	0x1000
+#define	PB11IOR 	0x0800
+#define	PB10IOR 	0x0400
+#define	PB9IOR 		0x0200
+#define	PB8IOR 		0x0100
+#define	PB7IOR 		0x0080
+#define	PB6IOR 		0x0040
+#define	PB5IOR 		0x0020
+#define	PB4IOR 		0x0010
+#define	PB3IOR 		0x0008
+#define	PB2IOR 		0x0004
+#define	PB1IOR 		0x0002
+#define	PB0IOR 		0x0001
+
+/*
+ * Port B Control Register (PBCR1)
+ */
+#define	PBCR1 		(*(volatile short *)(0x05FFFFCC))
+#define	PB15MD1 	0x8000
+#define	PB15MD0 	0x4000
+#define	PB14MD1 	0x2000
+#define	PB14MD0 	0x1000
+#define	PB13MD1 	0x0800
+#define	PB13MD0 	0x0400
+#define	PB12MD1 	0x0200
+#define	PB12MD0 	0x0100
+#define	PB11MD1 	0x0080
+#define	PB11MD0 	0x0040
+#define	PB10MD1 	0x0020
+#define	PB10MD0 	0x0010
+#define	PB9MD1 		0x0008
+#define	PB9MD0 		0x0004
+#define	PB8MD1 		0x0002
+#define	PB8MD0 		0x0001
+
+#define	PB15MD 		PB15MD1|PB14MD0
+#define	PB14MD 		PB14MD1|PB14MD0
+#define	PB13MD 		PB13MD1|PB13MD0
+#define	PB12MD 		PB12MD1|PB12MD0
+#define	PB11MD 		PB11MD1|PB11MD0
+#define	PB10MD 		PB10MD1|PB10MD0
+#define	PB9MD 		PB9MD1|PB9MD0
+#define	PB8MD 		PB8MD1|PB8MD0
+
+#define PB_TXD1 	PB11MD1
+#define PB_RXD1 	PB10MD1
+#define PB_TXD0 	PB9MD1
+#define PB_RXD0 	PB8MD1
+
+/*
+ * Port B Control Register (PBCR2)
+ */
+#define	PBCR2 	0x05FFFFCE
+#define	PB7MD1 	0x8000
+#define	PB7MD0 	0x4000
+#define	PB6MD1 	0x2000
+#define	PB6MD0 	0x1000
+#define	PB5MD1 	0x0800
+#define	PB5MD0 	0x0400
+#define	PB4MD1 	0x0200
+#define	PB4MD0 	0x0100
+#define	PB3MD1 	0x0080
+#define	PB3MD0 	0x0040
+#define	PB2MD1 	0x0020
+#define	PB2MD0 	0x0010
+#define	PB1MD1 	0x0008
+#define	PB1MD0 	0x0004
+#define	PB0MD1 	0x0002
+#define	PB0MD0 	0x0001
+	
+#define	PB7MD 	PB7MD1|PB7MD0
+#define	PB6MD 	PB6MD1|PB6MD0
+#define	PB5MD 	PB5MD1|PB5MD0
+#define	PB4MD 	PB4MD1|PB4MD0
+#define	PB3MD 	PB3MD1|PB3MD0
+#define	PB2MD 	PB2MD1|PB2MD0
+#define	PB1MD 	PB1MD1|PB1MD0
+#define	PB0MD 	PB0MD1|PB0MD0
+
+
+#ifdef MHZ
+#define BPS			32 * 9600 * MHZ / ( BAUD * 10)
+#else
+#define BPS			32	/* 9600 for 10 Mhz */
+#endif
+
+void handleError (char theSSR);
+
+void
+nop (void)
+{
+
+}
+void 
+init_serial (void)
+{
+  int i;
+
+  /* Clear TE and RE in Channel 1's SCR   */
+  SCR1 &= ~(SCI_TE | SCI_RE);
+
+  /* Set communication to be async, 8-bit data, no parity, 1 stop bit and use internal clock */
+
+  SMR1 = 0;
+  BRR1 = BPS;
+
+  SCR1 &= ~(SCI_CKE1 | SCI_CKE0);
+
+  /* let the hardware settle */
+
+  for (i = 0; i < 1000; i++)
+    nop ();
+
+  /* Turn on in and out */
+  SCR1 |= SCI_RE | SCI_TE;
+
+  /* Set the PFC to make RXD1 (pin PB8) an input pin and TXD1 (pin PB9) an output pin */
+  PBCR1 &= ~(PB_TXD1 | PB_RXD1);
+  PBCR1 |= PB_TXD1 | PB_RXD1;
+}
+
+
+int
+getDebugCharReady (void)
+{
+  char mySSR;
+  mySSR = SSR1 & ( SCI_PER | SCI_FER | SCI_ORER );
+  if ( mySSR )
+    handleError ( mySSR );
+  return SSR1 & SCI_RDRF ;
+}
+
+char 
+getDebugChar (void)
+{
+  char ch;
+  char mySSR;
+
+  while ( ! getDebugCharReady())
+    ;
+
+  ch = RDR1;
+  SSR1 &= ~SCI_RDRF;
+
+  mySSR = SSR1 & (SCI_PER | SCI_FER | SCI_ORER);
+
+  if (mySSR)
+    handleError (mySSR);
+
+  return ch;
+}
+
+int 
+putDebugCharReady (void)
+{
+  return (SSR1 & SCI_TDRE);
+}
+
+void
+putDebugChar (char ch)
+{
+  while (!putDebugCharReady())
+    ;
+
+  /*
+   * Write data into TDR and clear TDRE
+   */
+  TDR1 = ch;
+  SSR1 &= ~SCI_TDRE;
+}
+
+void 
+handleError (char theSSR)
+{
+  SSR1 &= ~(SCI_ORER | SCI_PER | SCI_FER);
+}
+
+#endif
diff --git a/gdb/stubs/sparc-stub.c b/gdb/stubs/sparc-stub.c
new file mode 100644
index 00000000000..c12d4360a4b
--- /dev/null
+++ b/gdb/stubs/sparc-stub.c
@@ -0,0 +1,778 @@
+/****************************************************************************
+
+		THIS SOFTWARE IS NOT COPYRIGHTED
+
+   HP offers the following for use in the public domain.  HP makes no
+   warranty with regard to the software or it's performance and the
+   user accepts the software "AS IS" with all faults.
+
+   HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
+   TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+
+****************************************************************************/
+
+/****************************************************************************
+ *  Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
+ *
+ *  Module name: remcom.c $
+ *  Revision: 1.34 $
+ *  Date: 91/03/09 12:29:49 $
+ *  Contributor:     Lake Stevens Instrument Division$
+ *
+ *  Description:     low level support for gdb debugger. $
+ *
+ *  Considerations:  only works on target hardware $
+ *
+ *  Written by:      Glenn Engel $
+ *  ModuleState:     Experimental $
+ *
+ *  NOTES:           See Below $
+ *
+ *  Modified for SPARC by Stu Grossman, Cygnus Support.
+ *
+ *  This code has been extensively tested on the Fujitsu SPARClite demo board.
+ *
+ *  To enable debugger support, two things need to happen.  One, a
+ *  call to set_debug_traps() is necessary in order to allow any breakpoints
+ *  or error conditions to be properly intercepted and reported to gdb.
+ *  Two, a breakpoint needs to be generated to begin communication.  This
+ *  is most easily accomplished by a call to breakpoint().  Breakpoint()
+ *  simulates a breakpoint by executing a trap #1.
+ *
+ *************
+ *
+ *    The following gdb commands are supported:
+ *
+ * command          function                               Return value
+ *
+ *    g             return the value of the CPU registers  hex data or ENN
+ *    G             set the value of the CPU registers     OK or ENN
+ *
+ *    mAA..AA,LLLL  Read LLLL bytes at address AA..AA      hex data or ENN
+ *    MAA..AA,LLLL: Write LLLL bytes at address AA.AA      OK or ENN
+ *
+ *    c             Resume at current address              SNN   ( signal NN)
+ *    cAA..AA       Continue at address AA..AA             SNN
+ *
+ *    s             Step one instruction                   SNN
+ *    sAA..AA       Step one instruction from AA..AA       SNN
+ *
+ *    k             kill
+ *
+ *    ?             What was the last sigval ?             SNN   (signal NN)
+ *
+ * All commands and responses are sent with a packet which includes a
+ * checksum.  A packet consists of
+ *
+ * $<packet info>#<checksum>.
+ *
+ * where
+ * <packet info> :: <characters representing the command or response>
+ * <checksum>    :: < two hex digits computed as modulo 256 sum of <packetinfo>>
+ *
+ * When a packet is received, it is first acknowledged with either '+' or '-'.
+ * '+' indicates a successful transfer.  '-' indicates a failed transfer.
+ *
+ * Example:
+ *
+ * Host:                  Reply:
+ * $m0,10#2a               +$00010203040506070809101112131415#42
+ *
+ ****************************************************************************/
+
+#include <string.h>
+#include <signal.h>
+
+/************************************************************************
+ *
+ * external low-level support routines
+ */
+
+extern void putDebugChar();	/* write a single character      */
+extern int getDebugChar();	/* read and return a single char */
+
+/************************************************************************/
+/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
+/* at least NUMREGBYTES*2 are needed for register packets */
+#define BUFMAX 2048
+
+static int initialized = 0;	/* !0 means we've been initialized */
+
+static void set_mem_fault_trap();
+
+static const char hexchars[]="0123456789abcdef";
+
+#define NUMREGS 72
+
+/* Number of bytes of registers.  */
+#define NUMREGBYTES (NUMREGS * 4)
+enum regnames {G0, G1, G2, G3, G4, G5, G6, G7,
+		 O0, O1, O2, O3, O4, O5, SP, O7,
+		 L0, L1, L2, L3, L4, L5, L6, L7,
+		 I0, I1, I2, I3, I4, I5, FP, I7,
+
+		 F0, F1, F2, F3, F4, F5, F6, F7,
+		 F8, F9, F10, F11, F12, F13, F14, F15,
+		 F16, F17, F18, F19, F20, F21, F22, F23,
+		 F24, F25, F26, F27, F28, F29, F30, F31,
+		 Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR };
+
+/***************************  ASSEMBLY CODE MACROS *************************/
+/* 									   */
+
+extern void trap_low();
+
+asm("
+	.reserve trapstack, 1000 * 4, \"bss\", 8
+
+	.data
+	.align	4
+
+in_trap_handler:
+	.word	0
+
+	.text
+	.align 4
+
+! This function is called when any SPARC trap (except window overflow or
+! underflow) occurs.  It makes sure that the invalid register window is still
+! available before jumping into C code.  It will also restore the world if you
+! return from handle_exception.
+
+	.globl _trap_low
+_trap_low:
+	mov	%psr, %l0
+	mov	%wim, %l3
+
+	srl	%l3, %l0, %l4		! wim >> cwp
+	cmp	%l4, 1
+	bne	window_fine		! Branch if not in the invalid window
+	nop
+
+! Handle window overflow
+
+	mov	%g1, %l4		! Save g1, we use it to hold the wim
+	srl	%l3, 1, %g1		! Rotate wim right
+	tst	%g1
+	bg	good_wim		! Branch if new wim is non-zero
+	nop
+
+! At this point, we need to bring a 1 into the high order bit of the wim.
+! Since we don't want to make any assumptions about the number of register
+! windows, we figure it out dynamically so as to setup the wim correctly.
+
+	not	%g1			! Fill g1 with ones
+	mov	%g1, %wim		! Fill the wim with ones
+	nop
+	nop
+	nop
+	mov	%wim, %g1		! Read back the wim
+	inc	%g1			! Now g1 has 1 just to left of wim
+	srl	%g1, 1, %g1		! Now put 1 at top of wim
+	mov	%g0, %wim		! Clear wim so that subsequent save
+	nop				!  won't trap
+	nop
+	nop
+
+good_wim:
+	save	%g0, %g0, %g0		! Slip into next window
+	mov	%g1, %wim		! Install the new wim
+
+	std	%l0, [%sp + 0 * 4]	! save L & I registers
+	std	%l2, [%sp + 2 * 4]
+	std	%l4, [%sp + 4 * 4]
+	std	%l6, [%sp + 6 * 4]
+
+	std	%i0, [%sp + 8 * 4]
+	std	%i2, [%sp + 10 * 4]
+	std	%i4, [%sp + 12 * 4]
+	std	%i6, [%sp + 14 * 4]
+
+	restore				! Go back to trap window.
+	mov	%l4, %g1		! Restore %g1
+
+window_fine:
+	sethi	%hi(in_trap_handler), %l4
+	ld	[%lo(in_trap_handler) + %l4], %l5
+	tst	%l5
+	bg	recursive_trap
+	inc	%l5
+
+	set	trapstack+1000*4, %sp	! Switch to trap stack
+
+recursive_trap:
+	st	%l5, [%lo(in_trap_handler) + %l4]
+	sub	%sp,(16+1+6+1+72)*4,%sp	! Make room for input & locals
+ 					! + hidden arg + arg spill
+					! + doubleword alignment
+					! + registers[72] local var
+
+	std	%g0, [%sp + (24 + 0) * 4] ! registers[Gx]
+	std	%g2, [%sp + (24 + 2) * 4]
+	std	%g4, [%sp + (24 + 4) * 4]
+	std	%g6, [%sp + (24 + 6) * 4]
+
+	std	%i0, [%sp + (24 + 8) * 4] ! registers[Ox]
+	std	%i2, [%sp + (24 + 10) * 4]
+	std	%i4, [%sp + (24 + 12) * 4]
+	std	%i6, [%sp + (24 + 14) * 4]
+					! F0->F31 not implemented
+	mov	%y, %l4
+	mov	%tbr, %l5
+	st	%l4, [%sp + (24 + 64) * 4] ! Y
+	st	%l0, [%sp + (24 + 65) * 4] ! PSR
+	st	%l3, [%sp + (24 + 66) * 4] ! WIM
+	st	%l5, [%sp + (24 + 67) * 4] ! TBR
+	st	%l1, [%sp + (24 + 68) * 4] ! PC
+	st	%l2, [%sp + (24 + 69) * 4] ! NPC
+
+					! CPSR and FPSR not impl
+
+	or	%l0, 0xf20, %l4
+	mov	%l4, %psr		! Turn on traps, disable interrupts
+
+	call	_handle_exception
+	add	%sp, 24 * 4, %o0	! Pass address of registers
+
+! Reload all of the registers that aren't on the stack
+
+	ld	[%sp + (24 + 1) * 4], %g1 ! registers[Gx]
+	ldd	[%sp + (24 + 2) * 4], %g2
+	ldd	[%sp + (24 + 4) * 4], %g4
+	ldd	[%sp + (24 + 6) * 4], %g6
+
+	ldd	[%sp + (24 + 8) * 4], %i0 ! registers[Ox]
+	ldd	[%sp + (24 + 10) * 4], %i2
+	ldd	[%sp + (24 + 12) * 4], %i4
+	ldd	[%sp + (24 + 14) * 4], %i6
+
+	ldd	[%sp + (24 + 64) * 4], %l0 ! Y & PSR
+	ldd	[%sp + (24 + 68) * 4], %l2 ! PC & NPC
+
+	restore				! Ensure that previous window is valid
+	save	%g0, %g0, %g0		!  by causing a window_underflow trap
+
+	mov	%l0, %y
+	mov	%l1, %psr		! Make sure that traps are disabled
+					! for rett
+
+	sethi	%hi(in_trap_handler), %l4
+	ld	[%lo(in_trap_handler) + %l4], %l5
+	dec	%l5
+	st	%l5, [%lo(in_trap_handler) + %l4]
+
+	jmpl	%l2, %g0		! Restore old PC
+	rett	%l3			! Restore old nPC
+");
+
+/* Convert ch from a hex digit to an int */
+
+static int
+hex (unsigned char ch)
+{
+  if (ch >= 'a' && ch <= 'f')
+    return ch-'a'+10;
+  if (ch >= '0' && ch <= '9')
+    return ch-'0';
+  if (ch >= 'A' && ch <= 'F')
+    return ch-'A'+10;
+  return -1;
+}
+
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
+
+/* scan for the sequence $<data>#<checksum>     */
+
+unsigned char *
+getpacket (void)
+{
+  unsigned char *buffer = &remcomInBuffer[0];
+  unsigned char checksum;
+  unsigned char xmitcsum;
+  int count;
+  char ch;
+
+  while (1)
+    {
+      /* wait around for the start character, ignore all other characters */
+      while ((ch = getDebugChar ()) != '$')
+	;
+
+retry:
+      checksum = 0;
+      xmitcsum = -1;
+      count = 0;
+
+      /* now, read until a # or end of buffer is found */
+      while (count < BUFMAX - 1)
+	{
+	  ch = getDebugChar ();
+          if (ch == '$')
+            goto retry;
+	  if (ch == '#')
+	    break;
+	  checksum = checksum + ch;
+	  buffer[count] = ch;
+	  count = count + 1;
+	}
+      buffer[count] = 0;
+
+      if (ch == '#')
+	{
+	  ch = getDebugChar ();
+	  xmitcsum = hex (ch) << 4;
+	  ch = getDebugChar ();
+	  xmitcsum += hex (ch);
+
+	  if (checksum != xmitcsum)
+	    {
+	      putDebugChar ('-');	/* failed checksum */
+	    }
+	  else
+	    {
+	      putDebugChar ('+');	/* successful transfer */
+
+	      /* if a sequence char is present, reply the sequence ID */
+	      if (buffer[2] == ':')
+		{
+		  putDebugChar (buffer[0]);
+		  putDebugChar (buffer[1]);
+
+		  return &buffer[3];
+		}
+
+	      return &buffer[0];
+	    }
+	}
+    }
+}
+
+/* send the packet in buffer.  */
+
+static void
+putpacket (unsigned char *buffer)
+{
+  unsigned char checksum;
+  int count;
+  unsigned char ch;
+
+  /*  $<packet info>#<checksum>. */
+  do
+    {
+      putDebugChar('$');
+      checksum = 0;
+      count = 0;
+
+      while (ch = buffer[count])
+	{
+	  putDebugChar(ch);
+	  checksum += ch;
+	  count += 1;
+	}
+
+      putDebugChar('#');
+      putDebugChar(hexchars[checksum >> 4]);
+      putDebugChar(hexchars[checksum & 0xf]);
+
+    }
+  while (getDebugChar() != '+');
+}
+
+/* Indicate to caller of mem2hex or hex2mem that there has been an
+   error.  */
+static volatile int mem_err = 0;
+
+/* Convert the memory pointed to by mem into hex, placing result in buf.
+ * Return a pointer to the last char put in buf (null), in case of mem fault,
+ * return 0.
+ * If MAY_FAULT is non-zero, then we will handle memory faults by returning
+ * a 0, else treat a fault like any other fault in the stub.
+ */
+
+static unsigned char *
+mem2hex (unsigned char *mem, unsigned char *buf, int count, int may_fault)
+{
+  unsigned char ch;
+
+  set_mem_fault_trap(may_fault);
+
+  while (count-- > 0)
+    {
+      ch = *mem++;
+      if (mem_err)
+	return 0;
+      *buf++ = hexchars[ch >> 4];
+      *buf++ = hexchars[ch & 0xf];
+    }
+
+  *buf = 0;
+
+  set_mem_fault_trap(0);
+
+  return buf;
+}
+
+/* convert the hex array pointed to by buf into binary to be placed in mem
+ * return a pointer to the character AFTER the last byte written */
+
+static char *
+hex2mem (unsigned char *buf, unsigned char *mem, int count, int may_fault)
+{
+  int i;
+  unsigned char ch;
+
+  set_mem_fault_trap(may_fault);
+
+  for (i=0; i<count; i++)
+    {
+      ch = hex(*buf++) << 4;
+      ch |= hex(*buf++);
+      *mem++ = ch;
+      if (mem_err)
+	return 0;
+    }
+
+  set_mem_fault_trap(0);
+
+  return mem;
+}
+
+/* This table contains the mapping between SPARC hardware trap types, and
+   signals, which are primarily what GDB understands.  It also indicates
+   which hardware traps we need to commandeer when initializing the stub. */
+
+static struct hard_trap_info
+{
+  unsigned char tt;		/* Trap type code for SPARClite */
+  unsigned char signo;		/* Signal that we map this trap into */
+} hard_trap_info[] = {
+  {1, SIGSEGV},			/* instruction access error */
+  {2, SIGILL},			/* privileged instruction */
+  {3, SIGILL},			/* illegal instruction */
+  {4, SIGEMT},			/* fp disabled */
+  {36, SIGEMT},			/* cp disabled */
+  {7, SIGBUS},			/* mem address not aligned */
+  {9, SIGSEGV},			/* data access exception */
+  {10, SIGEMT},			/* tag overflow */
+  {128+1, SIGTRAP},		/* ta 1 - normal breakpoint instruction */
+  {0, 0}			/* Must be last */
+};
+
+/* Set up exception handlers for tracing and breakpoints */
+
+void
+set_debug_traps (void)
+{
+  struct hard_trap_info *ht;
+
+  for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
+    exceptionHandler(ht->tt, trap_low);
+
+  initialized = 1;
+}
+
+asm ("
+! Trap handler for memory errors.  This just sets mem_err to be non-zero.  It
+! assumes that %l1 is non-zero.  This should be safe, as it is doubtful that
+! 0 would ever contain code that could mem fault.  This routine will skip
+! past the faulting instruction after setting mem_err.
+
+	.text
+	.align 4
+
+_fltr_set_mem_err:
+	sethi %hi(_mem_err), %l0
+	st %l1, [%l0 + %lo(_mem_err)]
+	jmpl %l2, %g0
+	rett %l2+4
+");
+
+static void
+set_mem_fault_trap (int enable)
+{
+  extern void fltr_set_mem_err();
+  mem_err = 0;
+
+  if (enable)
+    exceptionHandler(9, fltr_set_mem_err);
+  else
+    exceptionHandler(9, trap_low);
+}
+
+/* Convert the SPARC hardware trap type code to a unix signal number. */
+
+static int
+computeSignal (int tt)
+{
+  struct hard_trap_info *ht;
+
+  for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
+    if (ht->tt == tt)
+      return ht->signo;
+
+  return SIGHUP;		/* default for things we don't know about */
+}
+
+/*
+ * While we find nice hex chars, build an int.
+ * Return number of chars processed.
+ */
+
+static int
+hexToInt(char **ptr, int *intValue)
+{
+  int numChars = 0;
+  int hexValue;
+
+  *intValue = 0;
+
+  while (**ptr)
+    {
+      hexValue = hex(**ptr);
+      if (hexValue < 0)
+	break;
+
+      *intValue = (*intValue << 4) | hexValue;
+      numChars ++;
+
+      (*ptr)++;
+    }
+
+  return (numChars);
+}
+
+/*
+ * This function does all command procesing for interfacing to gdb.  It
+ * returns 1 if you should skip the instruction at the trap address, 0
+ * otherwise.
+ */
+
+extern void breakinst();
+
+static void
+handle_exception (unsigned long *registers)
+{
+  int tt;			/* Trap type */
+  int sigval;
+  int addr;
+  int length;
+  char *ptr;
+  unsigned long *sp;
+
+/* First, we must force all of the windows to be spilled out */
+
+  asm("	save %sp, -64, %sp
+	save %sp, -64, %sp
+	save %sp, -64, %sp
+	save %sp, -64, %sp
+	save %sp, -64, %sp
+	save %sp, -64, %sp
+	save %sp, -64, %sp
+	save %sp, -64, %sp
+	restore
+	restore
+	restore
+	restore
+	restore
+	restore
+	restore
+	restore
+");
+
+  if (registers[PC] == (unsigned long)breakinst)
+    {
+      registers[PC] = registers[NPC];
+      registers[NPC] += 4;
+    }
+
+  sp = (unsigned long *)registers[SP];
+
+  tt = (registers[TBR] >> 4) & 0xff;
+
+  /* reply to host that an exception has occurred */
+  sigval = computeSignal(tt);
+  ptr = remcomOutBuffer;
+
+  *ptr++ = 'T';
+  *ptr++ = hexchars[sigval >> 4];
+  *ptr++ = hexchars[sigval & 0xf];
+
+  *ptr++ = hexchars[PC >> 4];
+  *ptr++ = hexchars[PC & 0xf];
+  *ptr++ = ':';
+  ptr = mem2hex((char *)&registers[PC], ptr, 4, 0);
+  *ptr++ = ';';
+
+  *ptr++ = hexchars[FP >> 4];
+  *ptr++ = hexchars[FP & 0xf];
+  *ptr++ = ':';
+  ptr = mem2hex(sp + 8 + 6, ptr, 4, 0); /* FP */
+  *ptr++ = ';';
+
+  *ptr++ = hexchars[SP >> 4];
+  *ptr++ = hexchars[SP & 0xf];
+  *ptr++ = ':';
+  ptr = mem2hex((char *)&sp, ptr, 4, 0);
+  *ptr++ = ';';
+
+  *ptr++ = hexchars[NPC >> 4];
+  *ptr++ = hexchars[NPC & 0xf];
+  *ptr++ = ':';
+  ptr = mem2hex((char *)&registers[NPC], ptr, 4, 0);
+  *ptr++ = ';';
+
+  *ptr++ = hexchars[O7 >> 4];
+  *ptr++ = hexchars[O7 & 0xf];
+  *ptr++ = ':';
+  ptr = mem2hex((char *)&registers[O7], ptr, 4, 0);
+  *ptr++ = ';';
+
+  *ptr++ = 0;
+
+  putpacket(remcomOutBuffer);
+
+  while (1)
+    {
+      remcomOutBuffer[0] = 0;
+
+      ptr = getpacket();
+      switch (*ptr++)
+	{
+	case '?':
+	  remcomOutBuffer[0] = 'S';
+	  remcomOutBuffer[1] = hexchars[sigval >> 4];
+	  remcomOutBuffer[2] = hexchars[sigval & 0xf];
+	  remcomOutBuffer[3] = 0;
+	  break;
+
+	case 'd':		/* toggle debug flag */
+	  break;
+
+	case 'g':		/* return the value of the CPU registers */
+	  {
+	    ptr = remcomOutBuffer;
+	    ptr = mem2hex((char *)registers, ptr, 16 * 4, 0); /* G & O regs */
+	    ptr = mem2hex(sp + 0, ptr, 16 * 4, 0); /* L & I regs */
+	    memset(ptr, '0', 32 * 8); /* Floating point */
+	    mem2hex((char *)&registers[Y],
+		    ptr + 32 * 4 * 2,
+		    8 * 4,
+		    0);		/* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
+	  }
+	  break;
+
+	case 'G':	   /* set the value of the CPU registers - return OK */
+	  {
+	    unsigned long *newsp, psr;
+
+	    psr = registers[PSR];
+
+	    hex2mem(ptr, (char *)registers, 16 * 4, 0); /* G & O regs */
+	    hex2mem(ptr + 16 * 4 * 2, sp + 0, 16 * 4, 0); /* L & I regs */
+	    hex2mem(ptr + 64 * 4 * 2, (char *)&registers[Y],
+		    8 * 4, 0);	/* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
+
+	    /* See if the stack pointer has moved.  If so, then copy the saved
+	       locals and ins to the new location.  This keeps the window
+	       overflow and underflow routines happy.  */
+
+	    newsp = (unsigned long *)registers[SP];
+	    if (sp != newsp)
+	      sp = memcpy(newsp, sp, 16 * 4);
+
+	    /* Don't allow CWP to be modified. */
+
+	    if (psr != registers[PSR])
+	      registers[PSR] = (psr & 0x1f) | (registers[PSR] & ~0x1f);
+
+	    strcpy(remcomOutBuffer,"OK");
+	  }
+	  break;
+
+	case 'm':	  /* mAA..AA,LLLL  Read LLLL bytes at address AA..AA */
+	  /* Try to read %x,%x.  */
+
+	  if (hexToInt(&ptr, &addr)
+	      && *ptr++ == ','
+	      && hexToInt(&ptr, &length))
+	    {
+	      if (mem2hex((char *)addr, remcomOutBuffer, length, 1))
+		break;
+
+	      strcpy (remcomOutBuffer, "E03");
+	    }
+	  else
+	    strcpy(remcomOutBuffer,"E01");
+	  break;
+
+	case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
+	  /* Try to read '%x,%x:'.  */
+
+	  if (hexToInt(&ptr, &addr)
+	      && *ptr++ == ','
+	      && hexToInt(&ptr, &length)
+	      && *ptr++ == ':')
+	    {
+	      if (hex2mem(ptr, (char *)addr, length, 1))
+		strcpy(remcomOutBuffer, "OK");
+	      else
+		strcpy(remcomOutBuffer, "E03");
+	    }
+	  else
+	    strcpy(remcomOutBuffer, "E02");
+	  break;
+
+	case 'c':    /* cAA..AA    Continue at address AA..AA(optional) */
+	  /* try to read optional parameter, pc unchanged if no parm */
+
+	  if (hexToInt(&ptr, &addr))
+	    {
+	      registers[PC] = addr;
+	      registers[NPC] = addr + 4;
+	    }
+
+/* Need to flush the instruction cache here, as we may have deposited a
+   breakpoint, and the icache probably has no way of knowing that a data ref to
+   some location may have changed something that is in the instruction cache.
+ */
+
+	  flush_i_cache();
+	  return;
+
+	  /* kill the program */
+	case 'k' :		/* do nothing */
+	  break;
+#if 0
+	case 't':		/* Test feature */
+	  asm (" std %f30,[%sp]");
+	  break;
+#endif
+	case 'r':		/* Reset */
+	  asm ("call 0
+		nop ");
+	  break;
+	}			/* switch */
+
+      /* reply to the request */
+      putpacket(remcomOutBuffer);
+    }
+}
+
+/* This function will generate a breakpoint exception.  It is used at the
+   beginning of a program to sync up with a debugger and can be used
+   otherwise as a quick means to stop program execution and "break" into
+   the debugger. */
+
+void
+breakpoint (void)
+{
+  if (!initialized)
+    return;
+
+  asm("	.globl _breakinst
+
+	_breakinst: ta 1
+      ");
+}