GDB 7.6.50

opcodes/nios2-dis.c

Index: opcodes/nios2-dis.c
diff --git a/opcodes/nios2-dis.c b/opcodes/nios2-dis.c
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index 0000000000000000000000000000000000000000..ef7a5f96109b89b825a9a0356dfadd9de05e820c
--- /dev/null
+++ b/opcodes/nios2-dis.c
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+/* Altera Nios II disassemble routines
+   Copyright (C) 2012, 2013 Free Software Foundation, Inc.
+   Contributed by Nigel Gray (ngray@altera.com).
+   Contributed by Mentor Graphics, Inc.
+
+   This file is part of the GNU opcodes library.
+
+   This library 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 3, or (at your option)
+   any later version.
+
+   It 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 file; see the file COPYING.  If not, write to the
+   Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston,
+   MA 02110-1301, USA.  */
+
+#include "sysdep.h"
+#include "dis-asm.h"
+#include "opcode/nios2.h"
+#include "libiberty.h"
+#include <string.h>
+#include <assert.h>
+
+/* No symbol table is available when this code runs out in an embedded
+   system as when it is used for disassembler support in a monitor.  */
+#if !defined(EMBEDDED_ENV)
+#define SYMTAB_AVAILABLE 1
+#include "elf-bfd.h"
+#include "elf/nios2.h"
+#endif
+
+/* Length of Nios II instruction in bytes.  */
+#define INSNLEN 4
+
+/* Data structures used by the opcode hash table.  */
+typedef struct _nios2_opcode_hash
+{
+  const struct nios2_opcode *opcode;
+  struct _nios2_opcode_hash *next;
+} nios2_opcode_hash;
+
+static bfd_boolean nios2_hash_init = 0;
+static nios2_opcode_hash *nios2_hash[(OP_MASK_OP) + 1];
+
+/* Separate hash table for pseudo-ops.  */
+static nios2_opcode_hash *nios2_ps_hash[(OP_MASK_OP) + 1];
+
+/* Function to initialize the opcode hash table.  */
+static void
+nios2_init_opcode_hash (void)
+{
+  unsigned int i;
+  register const struct nios2_opcode *op;
+
+  for (i = 0; i <= OP_MASK_OP; ++i)
+    nios2_hash[0] = NULL;
+  for (i = 0; i <= OP_MASK_OP; i++)
+    for (op = nios2_opcodes; op < &nios2_opcodes[NUMOPCODES]; op++)
+      {
+	nios2_opcode_hash *new_hash;
+	nios2_opcode_hash **bucket = NULL;
+
+	if ((op->pinfo & NIOS2_INSN_MACRO) == NIOS2_INSN_MACRO)
+	  {
+	    if (i == ((op->match >> OP_SH_OP) & OP_MASK_OP)
+		&& (op->pinfo & (NIOS2_INSN_MACRO_MOV | NIOS2_INSN_MACRO_MOVI)
+		    & 0x7fffffff))
+	      bucket = &(nios2_ps_hash[i]);
+	  }
+	else if (i == ((op->match >> OP_SH_OP) & OP_MASK_OP))
+	  bucket = &(nios2_hash[i]);
+
+	if (bucket)
+	  {
+	    new_hash =
+	      (nios2_opcode_hash *) malloc (sizeof (nios2_opcode_hash));
+	    if (new_hash == NULL)
+	      {
+		fprintf (stderr,
+			 "error allocating memory...broken disassembler\n");
+		abort ();
+	      }
+	    new_hash->opcode = op;
+	    new_hash->next = NULL;
+	    while (*bucket)
+	      bucket = &((*bucket)->next);
+	    *bucket = new_hash;
+	  }
+      }
+  nios2_hash_init = 1;
+#ifdef DEBUG_HASHTABLE
+  for (i = 0; i <= OP_MASK_OP; ++i)
+    {
+      nios2_opcode_hash *tmp_hash = nios2_hash[i];
+      printf ("index: 0x%02X	ops: ", i);
+      while (tmp_hash != NULL)
+	{
+	  printf ("%s ", tmp_hash->opcode->name);
+	  tmp_hash = tmp_hash->next;
+	}
+      printf ("\n");
+    }
+
+  for (i = 0; i <= OP_MASK_OP; ++i)
+    {
+      nios2_opcode_hash *tmp_hash = nios2_ps_hash[i];
+      printf ("index: 0x%02X	ops: ", i);
+      while (tmp_hash != NULL)
+	{
+	  printf ("%s ", tmp_hash->opcode->name);
+	  tmp_hash = tmp_hash->next;
+	}
+      printf ("\n");
+    }
+#endif /* DEBUG_HASHTABLE */
+}
+
+/* Return a pointer to an nios2_opcode struct for a given instruction
+   opcode, or NULL if there is an error.  */
+const struct nios2_opcode *
+nios2_find_opcode_hash (unsigned long opcode)
+{
+  nios2_opcode_hash *entry;
+
+  /* Build a hash table to shorten the search time.  */
+  if (!nios2_hash_init)
+    nios2_init_opcode_hash ();
+
+  /* First look in the pseudo-op hashtable.  */
+  for (entry = nios2_ps_hash[(opcode >> OP_SH_OP) & OP_MASK_OP];
+       entry; entry = entry->next)
+    if (entry->opcode->match == (opcode & entry->opcode->mask))
+      return entry->opcode;
+
+  /* Otherwise look in the main hashtable.  */
+  for (entry = nios2_hash[(opcode >> OP_SH_OP) & OP_MASK_OP];
+       entry; entry = entry->next)
+    if (entry->opcode->match == (opcode & entry->opcode->mask))
+      return entry->opcode;
+
+  return NULL;
+}
+
+/* There are 32 regular registers, 32 coprocessor registers,
+   and 32 control registers.  */
+#define NUMREGNAMES 32
+
+/* Return a pointer to the base of the coprocessor register name array.  */
+static struct nios2_reg *
+nios2_coprocessor_regs (void)
+{
+  static struct nios2_reg *cached = NULL;
+  
+  if (!cached)
+    {
+      int i;
+      for (i = NUMREGNAMES; i < nios2_num_regs; i++)
+	if (!strcmp (nios2_regs[i].name, "c0"))
+	  {
+	    cached = nios2_regs + i;
+	    break;
+	  }
+      assert (cached);
+    }
+  return cached;
+}
+
+/* Return a pointer to the base of the control register name array.  */
+static struct nios2_reg *
+nios2_control_regs (void)
+{
+  static struct nios2_reg *cached = NULL;
+  
+  if (!cached)
+    {
+      int i;
+      for (i = NUMREGNAMES; i < nios2_num_regs; i++)
+	if (!strcmp (nios2_regs[i].name, "status"))
+	  {
+	    cached = nios2_regs + i;
+	    break;
+	  }
+      assert (cached);
+    }
+  return cached;
+}
+
+/* The function nios2_print_insn_arg uses the character pointed
+   to by ARGPTR to determine how it print the next token or separator
+   character in the arguments to an instruction.  */
+static int
+nios2_print_insn_arg (const char *argptr,
+		      unsigned long opcode, bfd_vma address,
+		      disassemble_info *info)
+{
+  unsigned long i = 0;
+  struct nios2_reg *reg_base;
+
+  switch (*argptr)
+    {
+    case ',':
+    case '(':
+    case ')':
+      (*info->fprintf_func) (info->stream, "%c", *argptr);
+      break;
+    case 'd':
+      i = GET_INSN_FIELD (RRD, opcode);
+
+      if (GET_INSN_FIELD (OP, opcode) == OP_MATCH_CUSTOM
+	  && GET_INSN_FIELD (CUSTOM_C, opcode) == 0)
+	reg_base = nios2_coprocessor_regs ();
+      else
+	reg_base = nios2_regs;
+
+      if (i < NUMREGNAMES)
+	(*info->fprintf_func) (info->stream, "%s", reg_base[i].name);
+      else
+	(*info->fprintf_func) (info->stream, "unknown");
+      break;
+    case 's':
+      i = GET_INSN_FIELD (RRS, opcode);
+
+      if (GET_INSN_FIELD (OP, opcode) == OP_MATCH_CUSTOM
+	  && GET_INSN_FIELD (CUSTOM_A, opcode) == 0)
+	reg_base = nios2_coprocessor_regs ();
+      else
+	reg_base = nios2_regs;
+
+      if (i < NUMREGNAMES)
+	(*info->fprintf_func) (info->stream, "%s", reg_base[i].name);
+      else
+	(*info->fprintf_func) (info->stream, "unknown");
+      break;
+    case 't':
+      i = GET_INSN_FIELD (RRT, opcode);
+
+      if (GET_INSN_FIELD (OP, opcode) == OP_MATCH_CUSTOM
+	  && GET_INSN_FIELD (CUSTOM_B, opcode) == 0)
+	reg_base = nios2_coprocessor_regs ();
+      else
+	reg_base = nios2_regs;
+
+      if (i < NUMREGNAMES)
+	(*info->fprintf_func) (info->stream, "%s", reg_base[i].name);
+      else
+	(*info->fprintf_func) (info->stream, "unknown");
+      break;
+    case 'i':
+      /* 16-bit signed immediate.  */
+      i = (signed) (GET_INSN_FIELD (IMM16, opcode) << 16) >> 16;
+      (*info->fprintf_func) (info->stream, "%ld", i);
+      break;
+    case 'u':
+      /* 16-bit unsigned immediate.  */
+      i = GET_INSN_FIELD (IMM16, opcode);
+      (*info->fprintf_func) (info->stream, "%ld", i);
+      break;
+    case 'o':
+      /* 16-bit signed immediate address offset.  */
+      i = (signed) (GET_INSN_FIELD (IMM16, opcode) << 16) >> 16;
+      address = address + 4 + i;
+      (*info->print_address_func) (address, info);
+      break;
+    case 'p':
+      /* 5-bit unsigned immediate.  */
+      i = GET_INSN_FIELD (CACHE_OPX, opcode);
+      (*info->fprintf_func) (info->stream, "%ld", i);
+      break;
+    case 'j':
+      /* 5-bit unsigned immediate.  */
+      i = GET_INSN_FIELD (IMM5, opcode);
+      (*info->fprintf_func) (info->stream, "%ld", i);
+      break;
+    case 'l':
+      /* 8-bit unsigned immediate.  */
+      /* FIXME - not yet implemented */
+      i = GET_INSN_FIELD (CUSTOM_N, opcode);
+      (*info->fprintf_func) (info->stream, "%lu", i);
+      break;
+    case 'm':
+      /* 26-bit unsigned immediate.  */
+      i = GET_INSN_FIELD (IMM26, opcode);
+      /* This translates to an address because it's only used in call
+	 instructions.  */
+      address = (address & 0xf0000000) | (i << 2);
+      (*info->print_address_func) (address, info);
+      break;
+    case 'c':
+      /* Control register index.  */
+      i = GET_INSN_FIELD (IMM5, opcode);
+      reg_base = nios2_control_regs ();
+      (*info->fprintf_func) (info->stream, "%s", reg_base[i].name);
+      break;
+    case 'b':
+      i = GET_INSN_FIELD (IMM5, opcode);
+      (*info->fprintf_func) (info->stream, "%ld", i);
+      break;
+    default:
+      (*info->fprintf_func) (info->stream, "unknown");
+      break;
+    }
+  return 0;
+}
+
+/* nios2_disassemble does all the work of disassembling a Nios II
+   instruction opcode.  */
+static int
+nios2_disassemble (bfd_vma address, unsigned long opcode,
+		   disassemble_info *info)
+{
+  const struct nios2_opcode *op;
+
+  info->bytes_per_line = INSNLEN;
+  info->bytes_per_chunk = INSNLEN;
+  info->display_endian = info->endian;
+  info->insn_info_valid = 1;
+  info->branch_delay_insns = 0;
+  info->data_size = 0;
+  info->insn_type = dis_nonbranch;
+  info->target = 0;
+  info->target2 = 0;
+
+  /* Find the major opcode and use this to disassemble
+     the instruction and its arguments.  */
+  op = nios2_find_opcode_hash (opcode);
+
+  if (op != NULL)
+    {
+      bfd_boolean is_nop = FALSE;
+      if (op->pinfo == NIOS2_INSN_MACRO_MOV)
+	{
+	  /* Check for mov r0, r0 and change to nop.  */
+	  int dst, src;
+	  dst = GET_INSN_FIELD (RRD, opcode);
+	  src = GET_INSN_FIELD (RRS, opcode);
+	  if (dst == 0 && src == 0)
+	    {
+	      (*info->fprintf_func) (info->stream, "nop");
+	      is_nop = TRUE;
+	    }
+	  else
+	    (*info->fprintf_func) (info->stream, "%s", op->name);
+	}
+      else
+	(*info->fprintf_func) (info->stream, "%s", op->name);
+
+      if (!is_nop)
+	{
+	  const char *argstr = op->args;
+	  if (argstr != NULL && *argstr != '\0')
+	    {
+	      (*info->fprintf_func) (info->stream, "\t");
+	      while (*argstr != '\0')
+		{
+		  nios2_print_insn_arg (argstr, opcode, address, info);
+		  ++argstr;
+		}
+	    }
+	}
+    }
+  else
+    {
+      /* Handle undefined instructions.  */
+      info->insn_type = dis_noninsn;
+      (*info->fprintf_func) (info->stream, "0x%lx", opcode);
+    }
+  /* Tell the caller how far to advance the program counter.  */
+  return INSNLEN;
+}
+
+
+/* print_insn_nios2 is the main disassemble function for Nios II.
+   The function diassembler(abfd) (source in disassemble.c) returns a
+   pointer to this either print_insn_big_nios2 or
+   print_insn_little_nios2, which in turn call this function when the
+   bfd machine type is Nios II. print_insn_nios2 reads the
+   instruction word at the address given, and prints the disassembled
+   instruction on the stream info->stream using info->fprintf_func. */
+
+static int
+print_insn_nios2 (bfd_vma address, disassemble_info *info,
+		  enum bfd_endian endianness)
+{
+  bfd_byte buffer[INSNLEN];
+  int status;
+
+  status = (*info->read_memory_func) (address, buffer, INSNLEN, info);
+  if (status == 0)
+    {
+      unsigned long insn;
+      if (endianness == BFD_ENDIAN_BIG)
+	insn = (unsigned long) bfd_getb32 (buffer);
+      else
+	insn = (unsigned long) bfd_getl32 (buffer);
+      status = nios2_disassemble (address, insn, info);
+    }
+  else
+    {
+      (*info->memory_error_func) (status, address, info);
+      status = -1;
+    }
+  return status;
+}
+
+/* These two functions are the main entry points, accessed from
+   disassemble.c.  */
+int
+print_insn_big_nios2 (bfd_vma address, disassemble_info *info)
+{
+  return print_insn_nios2 (address, info, BFD_ENDIAN_BIG);
+}
+
+int
+print_insn_little_nios2 (bfd_vma address, disassemble_info *info)
+{
+  return print_insn_nios2 (address, info, BFD_ENDIAN_LITTLE);
+}