aboutsummaryrefslogtreecommitdiff
path: root/gdb/mips-pinsn.c
blob: 39c82ffec0c76ab46d4a05ec70f5bb653226fed9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/* Print mips instructions for GDB, the GNU debugger.
   Copyright 1989, 1991 Free Software Foundation, Inc.
   Contributed by Nobuyuki Hikichi(hikichi@sra.co.jp)

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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "symtab.h"
#include "opcode/mips.h"

/* Mips instructions are never longer than this many bytes.  */
#define MAXLEN 4

/* Number of elements in the opcode table.  */
#define NOPCODES (sizeof mips_opcodes / sizeof mips_opcodes[0])

#define MKLONG(p)  *(unsigned long*)p

extern char *reg_names[];


/* subroutine */
static unsigned char *
print_insn_arg (d, l, stream, pc)
     char *d;
     register unsigned long int *l;
     FILE *stream;
     CORE_ADDR pc;
{
  switch (*d)
    {
    case ',':
    case '(':
    case ')':
      fputc (*d, stream);
      break;

    case 's':
      fprintf (stream, "$%s", reg_names[((struct op_i_fmt *) l)->rs]);
      break;

    case 't':
      fprintf (stream, "$%s", reg_names[((struct op_i_fmt *) l)->rt]);
      break;

    case 'i':
      fprintf (stream, "%d", ((struct op_i_fmt *) l)->immediate);
      break;

    case 'j': /* same as i, but sign-extended */
      fprintf (stream, "%d", ((struct op_b_fmt *) l)->delta);
      break;

    case 'a':
      print_address ((pc & 0xF0000000) | (((struct op_j_fmt *)l)->target << 2),
		     stream);
      break;

    case 'b':
      print_address ((((struct op_b_fmt *) l)->delta << 2) + pc + 4, stream);
      break;

    case 'd':
      fprintf (stream, "$%s", reg_names[((struct op_r_fmt *) l)->rd]);
      break;

    case 'h':
      fprintf (stream, "0x%x", ((struct op_r_fmt *) l)->shamt);
      break;

    case 'S':
      fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->fs);
      break;

    case 'T':
      fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->ft);
      break;

    case 'D':
      fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->fd);
      break;

    default:
      fprintf (stream, "# internal error, undefined modifier(%c)", *d);
      break;
    }
}

/* Print the mips instruction at address MEMADDR in debugged memory,
   on STREAM.  Returns length of the instruction, in bytes, which
   is always 4.  */

int
print_insn (memaddr, stream)
     CORE_ADDR memaddr;
     FILE *stream;
{
  unsigned char buffer[MAXLEN];
  register int i;
  register char *d;
  unsigned long int l;

  read_memory (memaddr, buffer, MAXLEN);

  for (i = 0; i < NOPCODES; i++)
    {
      register unsigned int opcode = mips_opcodes[i].opcode;
      register unsigned int match = mips_opcodes[i].match;
      if ((*(unsigned int*)buffer & match) == opcode)
	break;
    }

  l = MKLONG (buffer);
  /* Handle undefined instructions.  */
  if (i == NOPCODES)
    {
      fprintf (stream, "0x%x",l);
      return 4;
    }

  fprintf (stream, "%s", mips_opcodes[i].name);

  if (!(d = mips_opcodes[i].args))
    return 4;

  fputc (' ', stream);

  while (*d)
    print_insn_arg (d++, &l, stream, memaddr);

  return 4;
}