* The following block of changes add support for debugging assembly

	source files.
	* breakpoint.c (resolve_sal_pc):  Prevent crash when pc isn't
	associated with a function.
	* buildsym.c (record_line start_symtab end_symtab):  Don't delete
	symtabs which only have line numbers (but no other debug symbols).
	* dbxread.c (read_dbx_symtab end_psymtab):  Ditto.

	* remote-sim.c:  New functions gdbsim_insert/remove_breakpoint.  Use
	intrinsic simulator breakpoints if available, otherwise do it the
 	hard way.
	* configure.tgt:  Add d30v.
	* d30v-tdep.c:  New file.
	* config/d30v/d30v.mt, config/d30v/tm-d30v.h:  New files.

1 files changed, 1021 insertions, 0 deletions

diff --git a/gdb/d30v-tdep.c b/gdb/d30v-tdep.c
new file mode 100644
index 00000000000..eb889900c58
--- /dev/null
+++ b/gdb/d30v-tdep.c
@@ -0,0 +1,1021 @@
+/* Target-dependent code for Mitsubishi D30V, for GDB.
+   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/*  Contributed by Martin Hunt, hunt@cygnus.com */
+
+#include "defs.h"
+#include "frame.h"
+#include "obstack.h"
+#include "symtab.h"
+#include "gdbtypes.h"
+#include "gdbcmd.h"
+#include "gdbcore.h"
+#include "gdb_string.h"
+#include "value.h"
+#include "inferior.h"
+#include "dis-asm.h"  
+#include "symfile.h"
+#include "objfiles.h"
+
+void d30v_frame_find_saved_regs PARAMS ((struct frame_info *fi,
+					 struct frame_saved_regs *fsr));
+static void d30v_pop_dummy_frame PARAMS ((struct frame_info *fi));
+
+/* Discard from the stack the innermost frame, restoring all saved
+   registers.  */
+
+void
+d30v_pop_frame ()
+{
+  struct frame_info *frame = get_current_frame ();
+  CORE_ADDR fp;
+  int regnum;
+  struct frame_saved_regs fsr;
+  char raw_buffer[8];
+
+  fp = FRAME_FP (frame);
+  if (frame->dummy)
+    {
+      d30v_pop_dummy_frame(frame);
+      return;
+    }
+
+  /* fill out fsr with the address of where each */
+  /* register was stored in the frame */
+  get_frame_saved_regs (frame, &fsr);
+  
+  /* now update the current registers with the old values */
+  for (regnum = A0_REGNUM; regnum < A0_REGNUM+2 ; regnum++)
+    {
+      if (fsr.regs[regnum])
+	{
+	  read_memory (fsr.regs[regnum], raw_buffer, 8);
+	  write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 8);
+	}
+    }
+  for (regnum = 0; regnum < SP_REGNUM; regnum++)
+    {
+      if (fsr.regs[regnum])
+	{
+	  write_register (regnum, read_memory_unsigned_integer (fsr.regs[regnum], 2));
+	}
+    }
+  if (fsr.regs[PSW_REGNUM])
+    {
+      write_register (PSW_REGNUM, read_memory_unsigned_integer (fsr.regs[PSW_REGNUM], 2));
+    }
+
+  write_register (PC_REGNUM, read_register(13));
+  write_register (SP_REGNUM, fp + frame->size);
+  target_store_registers (-1);
+  flush_cached_frames ();
+}
+
+static int 
+check_prologue (op)
+     unsigned short op;
+{
+  /* st  rn, @-sp */
+  if ((op & 0x7E1F) == 0x6C1F)
+    return 1;
+
+  /* st2w  rn, @-sp */
+  if ((op & 0x7E3F) == 0x6E1F)
+    return 1;
+
+  /* subi  sp, n */
+  if ((op & 0x7FE1) == 0x01E1)
+    return 1;
+
+  /* mv  r11, sp */
+  if (op == 0x417E)
+    return 1;
+
+  /* nop */
+  if (op == 0x5E00)
+    return 1;
+
+  /* st  rn, @sp */
+  if ((op & 0x7E1F) == 0x681E)
+    return 1;
+
+  /* st2w  rn, @sp */
+ if ((op & 0x7E3F) == 0x3A1E)
+   return 1;
+
+  return 0;
+}
+
+CORE_ADDR
+d30v_skip_prologue (pc)
+     CORE_ADDR pc;
+{
+  unsigned long op;
+  unsigned short op1, op2;
+  CORE_ADDR func_addr, func_end;
+  struct symtab_and_line sal;
+
+  /* If we have line debugging information, then the end of the */
+  /* prologue should the first assembly instruction of  the first source line */
+  if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
+    {
+      sal = find_pc_line (func_addr, 0);
+      if ( sal.end && sal.end < func_end)
+	return sal.end;
+    }
+  
+  if (target_read_memory (pc, (char *)&op, 4))
+    return pc;			/* Can't access it -- assume no prologue. */
+
+  while (1)
+    {
+      op = (unsigned long)read_memory_integer (pc, 4);
+      if ((op & 0xC0000000) == 0xC0000000)
+	{
+	  /* long instruction */
+	  if ( ((op & 0x3FFF0000) != 0x01FF0000) &&   /* add3 sp,sp,n */
+	       ((op & 0x3F0F0000) != 0x340F0000) &&   /* st  rn, @(offset,sp) */
+ 	       ((op & 0x3F1F0000) != 0x350F0000))     /* st2w  rn, @(offset,sp) */
+	    break;
+	}
+      else
+	{
+	  /* short instructions */
+	  if ((op & 0xC0000000) == 0x80000000)
+	    {
+	      op2 = (op & 0x3FFF8000) >> 15;
+	      op1 = op & 0x7FFF;
+	    } 
+	  else 
+	    {
+	      op1 = (op & 0x3FFF8000) >> 15;
+	      op2 = op & 0x7FFF;
+	    }
+	  if (check_prologue(op1))
+	    {
+	      if (!check_prologue(op2))
+		{
+		  /* if the previous opcode was really part of the prologue */
+		  /* and not just a NOP, then we want to break after both instructions */
+		  if (op1 != 0x5E00)
+		    pc += 4;
+		  break;
+		}
+	    }
+	  else
+	    break;
+	}
+      pc += 4;
+    }
+  return pc;
+}
+
+/* Given a GDB frame, determine the address of the calling function's frame.
+   This will be used to create a new GDB frame struct, and then
+   INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
+*/
+
+CORE_ADDR
+d30v_frame_chain (frame)
+     struct frame_info *frame;
+{
+  struct frame_saved_regs fsr;
+
+  d30v_frame_find_saved_regs (frame, &fsr);
+
+  if (frame->return_pc == IMEM_START)
+    return (CORE_ADDR)0;
+
+  if (!fsr.regs[FP_REGNUM])
+    {
+      if (!fsr.regs[SP_REGNUM] || fsr.regs[SP_REGNUM] == STACK_START)
+	return (CORE_ADDR)0;
+      
+      return fsr.regs[SP_REGNUM];
+    }
+
+  if (!read_memory_unsigned_integer(fsr.regs[FP_REGNUM],2))
+    return (CORE_ADDR)0;
+
+  return read_memory_unsigned_integer(fsr.regs[FP_REGNUM],2)| DMEM_START;
+}  
+
+static int next_addr, uses_frame;
+
+static int 
+prologue_find_regs (op, fsr, addr)
+     unsigned short op;
+     struct frame_saved_regs *fsr;
+     CORE_ADDR addr;
+{
+  int n;
+
+  /* st  rn, @-sp */
+  if ((op & 0x7E1F) == 0x6C1F)
+    {
+      n = (op & 0x1E0) >> 5;
+      next_addr -= 2;
+      fsr->regs[n] = next_addr;
+      return 1;
+    }
+
+  /* st2w  rn, @-sp */
+  else if ((op & 0x7E3F) == 0x6E1F)
+    {
+      n = (op & 0x1E0) >> 5;
+      next_addr -= 4;
+      fsr->regs[n] = next_addr;
+      fsr->regs[n+1] = next_addr+2;
+      return 1;
+    }
+
+  /* subi  sp, n */
+  if ((op & 0x7FE1) == 0x01E1)
+    {
+      n = (op & 0x1E) >> 1;
+      if (n == 0)
+	n = 16;
+      next_addr -= n;
+      return 1;
+    }
+
+  /* mv  r11, sp */
+  if (op == 0x417E)
+    {
+      uses_frame = 1;
+      return 1;
+    }
+
+  /* nop */
+  if (op == 0x5E00)
+    return 1;
+
+  /* st  rn, @sp */
+  if ((op & 0x7E1F) == 0x681E)
+    {
+      n = (op & 0x1E0) >> 5;
+      fsr->regs[n] = next_addr;
+      return 1;
+    }
+
+  /* st2w  rn, @sp */
+  if ((op & 0x7E3F) == 0x3A1E)
+    {
+      n = (op & 0x1E0) >> 5;
+      fsr->regs[n] = next_addr;
+      fsr->regs[n+1] = next_addr+2;
+      return 1;
+    }
+
+  return 0;
+}
+
+/* Put here the code to store, into a struct frame_saved_regs, the
+   addresses of the saved registers of frame described by FRAME_INFO.
+   This includes special registers such as pc and fp saved in special
+   ways in the stack frame.  sp is even more special: the address we
+   return for it IS the sp for the next frame. */
+void
+d30v_frame_find_saved_regs (fi, fsr)
+     struct frame_info *fi;
+     struct frame_saved_regs *fsr;
+{
+  CORE_ADDR fp, pc;
+  unsigned long op;
+  unsigned short op1, op2;
+  int i;
+
+  fp = fi->frame;
+  memset (fsr, 0, sizeof (*fsr));
+  next_addr = 0;
+
+  pc = get_pc_function_start (fi->pc);
+
+  uses_frame = 0;
+  while (1)
+    {
+      op = (unsigned long)read_memory_integer (pc, 4);
+      if ((op & 0xC0000000) == 0xC0000000)
+	{
+	  /* long instruction */
+	  if ((op & 0x3FFF0000) == 0x01FF0000)
+	    {
+	      /* add3 sp,sp,n */
+	      short n = op & 0xFFFF;
+	      next_addr += n;
+	    }
+	  else if ((op & 0x3F0F0000) == 0x340F0000)
+	    {
+	      /* st  rn, @(offset,sp) */
+	      short offset = op & 0xFFFF;
+	      short n = (op >> 20) & 0xF;
+	      fsr->regs[n] = next_addr + offset;
+	    }
+	  else if ((op & 0x3F1F0000) == 0x350F0000)
+	    {
+	      /* st2w  rn, @(offset,sp) */
+	      short offset = op & 0xFFFF;
+	      short n = (op >> 20) & 0xF;
+	      fsr->regs[n] = next_addr + offset;
+	      fsr->regs[n+1] = next_addr + offset + 2;
+	    }
+	  else
+	    break;
+	}
+      else
+	{
+	  /* short instructions */
+	  if ((op & 0xC0000000) == 0x80000000)
+	    {
+	      op2 = (op & 0x3FFF8000) >> 15;
+	      op1 = op & 0x7FFF;
+	    } 
+	  else 
+	    {
+	      op1 = (op & 0x3FFF8000) >> 15;
+	      op2 = op & 0x7FFF;
+	    }
+	  if (!prologue_find_regs(op1,fsr,pc) || !prologue_find_regs(op2,fsr,pc))
+	    break;
+	}
+      pc += 4;
+    }
+  
+  fi->size = -next_addr;
+
+  if (!(fp & 0xffff))
+    fp = read_register(SP_REGNUM) | DMEM_START;
+
+  for (i=0; i<NUM_REGS-1; i++)
+    if (fsr->regs[i])
+      {
+	fsr->regs[i] = fp - (next_addr - fsr->regs[i]); 
+      }
+
+  if (fsr->regs[LR_REGNUM])
+    fi->return_pc = ((read_memory_unsigned_integer(fsr->regs[LR_REGNUM],2) - 1) << 2) | IMEM_START;
+  else
+    fi->return_pc = ((read_register(LR_REGNUM) - 1) << 2) | IMEM_START;
+  
+  /* th SP is not normally (ever?) saved, but check anyway */
+  if (!fsr->regs[SP_REGNUM])
+    {
+      /* if the FP was saved, that means the current FP is valid, */
+      /* otherwise, it isn't being used, so we use the SP instead */
+      if (uses_frame)
+	fsr->regs[SP_REGNUM] = read_register(FP_REGNUM) + fi->size;
+      else
+	{
+	  fsr->regs[SP_REGNUM] = fp + fi->size;
+	  fi->frameless = 1;
+	  fsr->regs[FP_REGNUM] = 0;
+	}
+    }
+}
+
+void
+d30v_init_extra_frame_info (fromleaf, fi)
+     int fromleaf;
+     struct frame_info *fi;
+{
+  struct frame_saved_regs dummy;
+
+  if (fi->next && ((fi->pc & 0xffff) == 0)) 
+    fi->pc = fi->next->return_pc; 
+
+  d30v_frame_find_saved_regs (fi, &dummy);
+}
+
+static void d30v_print_register PARAMS ((int regnum, int tabular));
+
+static void
+d30v_print_register (regnum, tabular)
+     int regnum;
+     int tabular;
+{
+  if (regnum < A0_REGNUM)
+    {
+      if (tabular)
+	printf_filtered ("%08x", read_register (regnum));
+      else
+	printf_filtered ("0x%x	%d", read_register (regnum),
+			 read_register (regnum));
+    }
+  else
+    {
+      char regbuf[MAX_REGISTER_RAW_SIZE];
+
+      read_relative_register_raw_bytes (regnum, regbuf);
+
+      val_print (REGISTER_VIRTUAL_TYPE (regnum), regbuf, 0,
+		 gdb_stdout, 'x', 1, 0, Val_pretty_default);
+
+      if (!tabular)
+	{
+	  printf_filtered ("	");
+	  val_print (REGISTER_VIRTUAL_TYPE (regnum), regbuf, 0,
+		 gdb_stdout, 'd', 1, 0, Val_pretty_default);
+	}
+    }
+}
+
+void
+d30v_do_registers_info (regnum, fpregs)
+     int regnum;
+     int fpregs;
+{
+  long long num1, num2;
+
+  if (regnum != -1)
+    {
+      if (reg_names[0] == NULL || reg_names[0][0] == '\000')
+	return;
+
+      printf_filtered ("%s ", reg_names[regnum]);
+      d30v_print_register (regnum, 0);
+
+      printf_filtered ("\n");
+      return;
+    }
+
+  /* Have to print all the registers.  Format them nicely.  */
+
+  printf_filtered ("PC=");
+  print_address (read_pc (), gdb_stdout);
+
+  printf_filtered (" PSW=");
+  d30v_print_register (PSW_REGNUM, 1);
+
+  printf_filtered (" BPC=");
+  print_address (read_register (BPC_REGNUM), gdb_stdout);
+
+  printf_filtered (" BPSW=");
+  d30v_print_register (BPSW_REGNUM, 1);
+  printf_filtered ("\n");
+
+  printf_filtered ("DPC=");
+  print_address (read_register (DPC_REGNUM), gdb_stdout);
+
+  printf_filtered (" DPSW=");
+  d30v_print_register (DPSW_REGNUM, 1);
+
+  printf_filtered (" IBA=");
+  print_address (read_register (IBA_REGNUM), gdb_stdout);
+  printf_filtered ("\n");
+
+  printf_filtered ("RPT_C=");
+  d30v_print_register (RPT_C_REGNUM, 1);
+
+  printf_filtered (" RPT_S=");
+  print_address (read_register (RPT_S_REGNUM), gdb_stdout);
+
+  printf_filtered (" RPT_E=");
+  print_address (read_register (RPT_E_REGNUM), gdb_stdout);
+  printf_filtered ("\n");
+
+  printf_filtered ("MOD_S=");
+  print_address (read_register (MOD_S_REGNUM), gdb_stdout);
+
+  printf_filtered (" MOD_E=");
+  print_address (read_register (MOD_E_REGNUM), gdb_stdout);
+  printf_filtered ("\n");
+
+  printf_filtered ("EIT_VB=");
+  print_address (read_register (EIT_VB_REGNUM), gdb_stdout);
+
+  printf_filtered (" INT_S=");
+  d30v_print_register (INT_S_REGNUM, 1);
+
+  printf_filtered (" INT_M=");
+  d30v_print_register (INT_M_REGNUM, 1);
+  printf_filtered ("\n");
+
+  for (regnum = 0; regnum <= 63;)
+    {
+      int i;
+
+      printf_filtered ("R%d-R%d ", regnum, regnum + 7);
+      if (regnum < 10)
+	printf_filtered (" ");
+      if (regnum + 7 < 10)
+	printf_filtered (" ");
+
+      for (i = 0; i < 8; i++)
+	{
+	  printf_filtered (" ");
+	  d30v_print_register (regnum++, 1);
+	}
+
+      printf_filtered ("\n");
+    }
+
+  printf_filtered ("A0-A1    ");
+
+  d30v_print_register (A0_REGNUM, 1);
+  printf_filtered ("    ");
+  d30v_print_register (A1_REGNUM, 1);
+  printf_filtered ("\n");
+}
+
+CORE_ADDR
+d30v_fix_call_dummy (dummyname, start_sp, fun, nargs, args, type, gcc_p)
+     char *dummyname;
+     CORE_ADDR start_sp;
+     CORE_ADDR fun;
+     int nargs;
+     value_ptr *args;
+     struct type *type;
+     int gcc_p;
+{
+  int regnum;
+  CORE_ADDR sp;
+  char buffer[MAX_REGISTER_RAW_SIZE];
+  struct frame_info *frame = get_current_frame ();
+  frame->dummy = start_sp;
+  start_sp |= DMEM_START;
+
+  sp = start_sp;
+  for (regnum = 0; regnum < NUM_REGS; regnum++)
+    {
+      sp -= REGISTER_RAW_SIZE(regnum);
+      store_address (buffer, REGISTER_RAW_SIZE(regnum), read_register(regnum));
+      write_memory (sp, buffer, REGISTER_RAW_SIZE(regnum));
+    }
+  write_register (SP_REGNUM, (LONGEST)(sp & 0xffff)); 
+  /* now we need to load LR with the return address */
+  write_register (LR_REGNUM, (LONGEST)(d30v_call_dummy_address() & 0xffff) >> 2);  
+  return sp;
+}
+
+static void
+d30v_pop_dummy_frame (fi)
+     struct frame_info *fi;
+{
+  CORE_ADDR sp = fi->dummy;
+  int regnum;
+
+  for (regnum = 0; regnum < NUM_REGS; regnum++)
+    {
+      sp -= REGISTER_RAW_SIZE(regnum);
+      write_register(regnum, read_memory_unsigned_integer (sp, REGISTER_RAW_SIZE(regnum)));
+    }
+  flush_cached_frames (); /* needed? */
+}
+
+
+CORE_ADDR
+d30v_push_arguments (nargs, args, sp, struct_return, struct_addr)
+     int nargs;
+     value_ptr *args;
+     CORE_ADDR sp;
+     int struct_return;
+     CORE_ADDR struct_addr;
+{
+  int i, len, index=0, regnum=2;
+  char buffer[4], *contents;
+  LONGEST val;
+  CORE_ADDR ptrs[10];
+
+  /* Pass 1. Put all large args on stack */
+  for (i = 0; i < nargs; i++)
+    {
+      value_ptr arg = args[i];
+      struct type *arg_type = check_typedef (VALUE_TYPE (arg));
+      len = TYPE_LENGTH (arg_type);
+      contents = VALUE_CONTENTS(arg);
+      val = extract_signed_integer (contents, len);
+      if (len > 4)
+	{
+	  /* put on stack and pass pointers */
+	  sp -= len;
+	  write_memory (sp, contents, len);
+	  ptrs[index++] = sp;
+	}
+    }
+
+  index = 0;
+
+  for (i = 0; i < nargs; i++)
+    {
+      value_ptr arg = args[i];
+      struct type *arg_type = check_typedef (VALUE_TYPE (arg));
+      len = TYPE_LENGTH (arg_type);
+      contents = VALUE_CONTENTS(arg);
+      val = extract_signed_integer (contents, len);
+      if (len > 4)
+	{
+	  /* use a pointer to previously saved data */
+	  if (regnum < 6)
+	    write_register (regnum++, ptrs[index++]);
+	  else
+	    {
+	      /* no more registers available.  put it on the stack */
+	      sp -= 2;
+	      store_address (buffer, 2, ptrs[index++]);
+	      write_memory (sp, buffer, 2);
+	    }
+	}
+      else
+	{
+	  if (regnum < 6 )
+	    {
+	      if (len == 4)
+		write_register (regnum++, val>>16);
+	      write_register (regnum++, val & 0xffff);
+	    }
+	  else
+	    {
+	      sp -= len;
+	      store_address (buffer, len, val);
+	      write_memory (sp, buffer, len);
+	    }
+	}
+    }
+  return sp;
+}
+
+
+/* pick an out-of-the-way place to set the return value */
+/* for an inferior function call.  The link register is set to this  */
+/* value and a momentary breakpoint is set there.  When the breakpoint */
+/* is hit, the dummy frame is popped and the previous environment is */
+/* restored. */
+
+CORE_ADDR
+d30v_call_dummy_address ()
+{
+  CORE_ADDR entry;
+  struct minimal_symbol *sym;
+
+  entry = entry_point_address ();
+
+  if (entry != 0)
+    return entry;
+
+  sym = lookup_minimal_symbol ("_start", NULL, symfile_objfile);
+
+  if (!sym || MSYMBOL_TYPE (sym) != mst_text)
+    return 0;
+  else
+    return SYMBOL_VALUE_ADDRESS (sym);
+}
+
+/* Given a return value in `regbuf' with a type `valtype', 
+   extract and copy its value into `valbuf'.  */
+
+void
+d30v_extract_return_value (valtype, regbuf, valbuf)
+     struct type *valtype;
+     char regbuf[REGISTER_BYTES];
+     char *valbuf;
+{
+  memcpy (valbuf, regbuf + REGISTER_BYTE (2), TYPE_LENGTH (valtype));
+}
+
+/* The following code implements access to, and display of, the D30V's
+   instruction trace buffer.  The buffer consists of 64K or more
+   4-byte words of data, of which each words includes an 8-bit count,
+   an 8-bit segment number, and a 16-bit instruction address.
+
+   In theory, the trace buffer is continuously capturing instruction
+   data that the CPU presents on its "debug bus", but in practice, the
+   ROMified GDB stub only enables tracing when it continues or steps
+   the program, and stops tracing when the program stops; so it
+   actually works for GDB to read the buffer counter out of memory and
+   then read each trace word.  The counter records where the tracing
+   stops, but there is no record of where it started, so we remember
+   the PC when we resumed and then search backwards in the trace
+   buffer for a word that includes that address.  This is not perfect,
+   because you will miss trace data if the resumption PC is the target
+   of a branch.  (The value of the buffer counter is semi-random, any
+   trace data from a previous program stop is gone.)  */
+
+/* The address of the last word recorded in the trace buffer.  */
+
+#define DBBC_ADDR (0xd80000)
+
+/* The base of the trace buffer, at least for the "Board_0".  */
+
+#define TRACE_BUFFER_BASE (0xf40000)
+
+static void trace_command PARAMS ((char *, int));
+
+static void untrace_command PARAMS ((char *, int));
+
+static void trace_info PARAMS ((char *, int));
+
+static void tdisassemble_command PARAMS ((char *, int));
+
+static void display_trace PARAMS ((int, int));
+
+/* True when instruction traces are being collected.  */
+
+static int tracing;
+
+/* Remembered PC.  */
+
+static CORE_ADDR last_pc;
+
+/* True when trace output should be displayed whenever program stops.  */
+
+static int trace_display;
+
+/* True when trace listing should include source lines.  */
+
+static int default_trace_show_source = 1;
+
+struct trace_buffer {
+  int size;
+  short *counts;
+  CORE_ADDR *addrs;
+} trace_data;
+
+static void
+trace_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  /* Clear the host-side trace buffer, allocating space if needed.  */
+  trace_data.size = 0;
+  if (trace_data.counts == NULL)
+    trace_data.counts = (short *) xmalloc (65536 * sizeof(short));
+  if (trace_data.addrs == NULL)
+    trace_data.addrs = (CORE_ADDR *) xmalloc (65536 * sizeof(CORE_ADDR));
+
+  tracing = 1;
+
+  printf_filtered ("Tracing is now on.\n");
+}
+
+static void
+untrace_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  tracing = 0;
+
+  printf_filtered ("Tracing is now off.\n");
+}
+
+static void
+trace_info (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  int i;
+
+  if (trace_data.size)
+    {
+      printf_filtered ("%d entries in trace buffer:\n", trace_data.size);
+
+      for (i = 0; i < trace_data.size; ++i)
+	{
+	  printf_filtered ("%d: %d instruction%s at 0x%x\n",
+			   i, trace_data.counts[i],
+			   (trace_data.counts[i] == 1 ? "" : "s"),
+			   trace_data.addrs[i]);
+	}
+    }
+  else
+    printf_filtered ("No entries in trace buffer.\n");
+
+  printf_filtered ("Tracing is currently %s.\n", (tracing ? "on" : "off"));
+}
+
+/* Print the instruction at address MEMADDR in debugged memory,
+   on STREAM.  Returns length of the instruction, in bytes.  */
+
+static int
+print_insn (memaddr, stream)
+     CORE_ADDR memaddr;
+     GDB_FILE *stream;
+{
+  /* If there's no disassembler, something is very wrong.  */
+  if (tm_print_insn == NULL)
+    abort ();
+
+  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
+    tm_print_insn_info.endian = BFD_ENDIAN_BIG;
+  else
+    tm_print_insn_info.endian = BFD_ENDIAN_LITTLE;
+  return (*tm_print_insn) (memaddr, &tm_print_insn_info);
+}
+
+void
+d30v_eva_prepare_to_trace ()
+{
+  if (!tracing)
+    return;
+
+  last_pc = read_register (PC_REGNUM);
+}
+
+/* Collect trace data from the target board and format it into a form
+   more useful for display.  */
+
+void
+d30v_eva_get_trace_data ()
+{
+  int count, i, j, oldsize;
+  int trace_addr, trace_seg, trace_cnt, next_cnt;
+  unsigned int last_trace, trace_word, next_word;
+  unsigned int *tmpspace;
+
+  if (!tracing)
+    return;
+
+  tmpspace = xmalloc (65536 * sizeof(unsigned int));
+
+  last_trace = read_memory_unsigned_integer (DBBC_ADDR, 2) << 2;
+
+  /* Collect buffer contents from the target, stopping when we reach
+     the word recorded when execution resumed.  */
+
+  count = 0;
+  while (last_trace > 0)
+    {
+      QUIT;
+      trace_word =
+	read_memory_unsigned_integer (TRACE_BUFFER_BASE + last_trace, 4);
+      trace_addr = trace_word & 0xffff;
+      last_trace -= 4;
+      /* Ignore an apparently nonsensical entry.  */
+      if (trace_addr == 0xffd5)
+	continue;
+      tmpspace[count++] = trace_word;
+      if (trace_addr == last_pc)
+	break;
+      if (count > 65535)
+	break;
+    }
+
+  /* Move the data to the host-side trace buffer, adjusting counts to
+     include the last instruction executed and transforming the address
+     into something that GDB likes.  */
+
+  for (i = 0; i < count; ++i)
+    {
+      trace_word = tmpspace[i];
+      next_word = ((i == 0) ? 0 : tmpspace[i - 1]);
+      trace_addr = trace_word & 0xffff;
+      next_cnt = (next_word >> 24) & 0xff;
+      j = trace_data.size + count - i - 1;
+      trace_data.addrs[j] = (trace_addr << 2) + 0x1000000;
+      trace_data.counts[j] = next_cnt + 1;
+    }
+
+  oldsize = trace_data.size;
+  trace_data.size += count;
+
+  free (tmpspace);
+
+  if (trace_display)
+    display_trace (oldsize, trace_data.size);
+}
+
+static void
+tdisassemble_command (arg, from_tty)
+     char *arg;
+     int from_tty;
+{
+  int i, count;
+  CORE_ADDR low, high;
+  char *space_index;
+
+  if (!arg)
+    {
+      low = 0;
+      high = trace_data.size;
+    }
+  else if (!(space_index = (char *) strchr (arg, ' ')))
+    {
+      low = parse_and_eval_address (arg);
+      high = low + 5;
+    }
+  else
+    {
+      /* Two arguments.  */
+      *space_index = '\0';
+      low = parse_and_eval_address (arg);
+      high = parse_and_eval_address (space_index + 1);
+      if (high < low)
+	high = low;
+    }
+
+  printf_filtered ("Dump of trace from %d to %d:\n", low, high);
+
+  display_trace (low, high);
+
+  printf_filtered ("End of trace dump.\n");
+  gdb_flush (gdb_stdout);
+}
+
+static void
+display_trace (low, high)
+     int low, high;
+{
+  int i, count, trace_show_source, first, suppress;
+  CORE_ADDR next_address;
+
+  trace_show_source = default_trace_show_source;
+  if (!have_full_symbols () && !have_partial_symbols())
+    {
+      trace_show_source = 0;
+      printf_filtered ("No symbol table is loaded.  Use the \"file\" command.\n");
+      printf_filtered ("Trace will not display any source.\n");
+    }
+
+  first = 1;
+  suppress = 0;
+  for (i = low; i < high; ++i)
+    {
+      next_address = trace_data.addrs[i];
+      count = trace_data.counts[i]; 
+      while (count-- > 0)
+	{
+	  QUIT;
+	  if (trace_show_source)
+	    {
+	      struct symtab_and_line sal, sal_prev;
+
+	      sal_prev = find_pc_line (next_address - 4, 0);
+	      sal = find_pc_line (next_address, 0);
+
+	      if (sal.symtab)
+		{
+		  if (first || sal.line != sal_prev.line)
+		    print_source_lines (sal.symtab, sal.line, sal.line + 1, 0);
+		  suppress = 0;
+		}
+	      else
+		{
+		  if (!suppress)
+		    /* FIXME-32x64--assumes sal.pc fits in long.  */
+		    printf_filtered ("No source file for address %s.\n",
+				     local_hex_string((unsigned long) sal.pc));
+		  suppress = 1;
+		}
+	    }
+	  first = 0;
+	  print_address (next_address, gdb_stdout);
+	  printf_filtered (":");
+	  printf_filtered ("\t");
+	  wrap_here ("    ");
+	  next_address = next_address + print_insn (next_address, gdb_stdout);
+	  printf_filtered ("\n");
+	  gdb_flush (gdb_stdout);
+	}
+    }
+}
+
+extern void (*target_resume_hook) PARAMS ((void));
+extern void (*target_wait_loop_hook) PARAMS ((void));
+
+void
+_initialize_d30v_tdep ()
+{
+  tm_print_insn = print_insn_d30v;
+
+  target_resume_hook = d30v_eva_prepare_to_trace;
+  target_wait_loop_hook = d30v_eva_get_trace_data;
+
+  add_com ("trace", class_support, trace_command,
+	   "Enable tracing of instruction execution.");
+
+  add_com ("untrace", class_support, untrace_command,
+	   "Disable tracing of instruction execution.");
+
+  add_com ("tdisassemble", class_vars, tdisassemble_command,
+	   "Disassemble the trace buffer.\n\
+Two optional arguments specify a range of trace buffer entries\n\
+as reported by info trace (NOT addresses!).");
+
+  add_info ("trace", trace_info,
+	    "Display info about the trace data buffer.");
+
+  add_show_from_set (add_set_cmd ("tracedisplay", no_class,
+				  var_integer, (char *)&trace_display,
+				  "Set automatic display of trace.\n", &setlist),
+		     &showlist);
+  add_show_from_set (add_set_cmd ("tracesource", no_class,
+				  var_integer, (char *)&default_trace_show_source,
+				  "Set display of source code with trace.\n", &setlist),
+		     &showlist);
+
+}