1 /* Print VAX instructions.
2 Copyright 1995, 1998, 2000, 2001, 2002 Free Software Foundation, Inc.
3 Contributed by Pauline Middelink <middelin@polyware.iaf.nl>
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18
19 #include "sysdep.h"
20 #include "opcode/vax.h"
21 #include "dis-asm.h"
22
23 /* Local function prototypes */
24 static int fetch_data PARAMS ((struct disassemble_info *, bfd_byte *));
25 static int print_insn_arg
26 PARAMS ((const char *, unsigned char *, bfd_vma, disassemble_info *));
27 static int print_insn_mode
28 PARAMS ((const char *, int, unsigned char *, bfd_vma, disassemble_info *));
29
30
31 static char *reg_names[] =
32 {
33 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
34 "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc"
35 };
36
37 /* Sign-extend an (unsigned char). */
38 #if __STDC__ == 1
39 #define COERCE_SIGNED_CHAR(ch) ((signed char)(ch))
40 #else
41 #define COERCE_SIGNED_CHAR(ch) ((int)(((ch) ^ 0x80) & 0xFF) - 128)
42 #endif
43
44 /* Get a 1 byte signed integer. */
45 #define NEXTBYTE(p) \
46 (p += 1, FETCH_DATA (info, p), \
47 COERCE_SIGNED_CHAR(p[-1]))
48
49 /* Get a 2 byte signed integer. */
50 #define COERCE16(x) ((int) (((x) ^ 0x8000) - 0x8000))
51 #define NEXTWORD(p) \
52 (p += 2, FETCH_DATA (info, p), \
53 COERCE16 ((p[-1] << 8) + p[-2]))
54
55 /* Get a 4 byte signed integer. */
56 #define COERCE32(x) ((int) (((x) ^ 0x80000000) - 0x80000000))
57 #define NEXTLONG(p) \
58 (p += 4, FETCH_DATA (info, p), \
59 (COERCE32 ((((((p[-1] << 8) + p[-2]) << 8) + p[-3]) << 8) + p[-4])))
60
61 /* Maximum length of an instruction. */
62 #define MAXLEN 25
63
64 #include <setjmp.h>
65
66 struct private
67 {
68 /* Points to first byte not fetched. */
69 bfd_byte *max_fetched;
70 bfd_byte the_buffer[MAXLEN];
71 bfd_vma insn_start;
72 jmp_buf bailout;
73 };
74
75 /* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive)
76 to ADDR (exclusive) are valid. Returns 1 for success, longjmps
77 on error. */
78 #define FETCH_DATA(info, addr) \
79 ((addr) <= ((struct private *)(info->private_data))->max_fetched \
80 ? 1 : fetch_data ((info), (addr)))
81
82 static int
fetch_data(info,addr)83 fetch_data (info, addr)
84 struct disassemble_info *info;
85 bfd_byte *addr;
86 {
87 int status;
88 struct private *priv = (struct private *) info->private_data;
89 bfd_vma start = priv->insn_start + (priv->max_fetched - priv->the_buffer);
90
91 status = (*info->read_memory_func) (start,
92 priv->max_fetched,
93 addr - priv->max_fetched,
94 info);
95 if (status != 0)
96 {
97 (*info->memory_error_func) (status, start, info);
98 longjmp (priv->bailout, 1);
99 }
100 else
101 priv->max_fetched = addr;
102
103 return 1;
104 }
105
106 /* Print the vax instruction at address MEMADDR in debugged memory,
107 on INFO->STREAM. Returns length of the instruction, in bytes. */
108
109 int
print_insn_vax(memaddr,info)110 print_insn_vax (memaddr, info)
111 bfd_vma memaddr;
112 disassemble_info *info;
113 {
114 const struct vot *votp;
115 const char *argp;
116 unsigned char *arg;
117 struct private priv;
118 bfd_byte *buffer = priv.the_buffer;
119
120 info->private_data = (PTR) &priv;
121 priv.max_fetched = priv.the_buffer;
122 priv.insn_start = memaddr;
123
124 if (setjmp (priv.bailout) != 0)
125 {
126 /* Error return. */
127 return -1;
128 }
129
130 argp = NULL;
131 /* Check if the info buffer has more than one byte left since
132 the last opcode might be a single byte with no argument data. */
133 if (info->buffer_length - (memaddr - info->buffer_vma) > 1)
134 {
135 FETCH_DATA (info, buffer + 2);
136 }
137 else
138 {
139 FETCH_DATA (info, buffer + 1);
140 buffer[1] = 0;
141 }
142
143 for (votp = &votstrs[0]; votp->name[0]; votp++)
144 {
145 register vax_opcodeT opcode = votp->detail.code;
146
147 /* 2 byte codes match 2 buffer pos. */
148 if ((bfd_byte) opcode == buffer[0]
149 && (opcode >> 8 == 0 || opcode >> 8 == buffer[1]))
150 {
151 argp = votp->detail.args;
152 break;
153 }
154 }
155 if (argp == NULL)
156 {
157 /* Handle undefined instructions. */
158 (*info->fprintf_func) (info->stream, ".word 0x%x",
159 (buffer[0] << 8) + buffer[1]);
160 return 2;
161 }
162
163 /* Point at first byte of argument data, and at descriptor for first
164 argument. */
165 arg = buffer + ((votp->detail.code >> 8) ? 2 : 1);
166
167 /* Make sure we have it in mem */
168 FETCH_DATA (info, arg);
169
170 (*info->fprintf_func) (info->stream, "%s", votp->name);
171 if (*argp)
172 (*info->fprintf_func) (info->stream, " ");
173
174 while (*argp)
175 {
176 arg += print_insn_arg (argp, arg, memaddr + arg - buffer, info);
177 argp += 2;
178 if (*argp)
179 (*info->fprintf_func) (info->stream, ",");
180 }
181
182 return arg - buffer;
183 }
184
185 /* Returns number of bytes "eaten" by the operand, or return -1 if an
186 invalid operand was found, or -2 if an opcode tabel error was
187 found. */
188
189 static int
print_insn_arg(d,p0,addr,info)190 print_insn_arg (d, p0, addr, info)
191 const char *d;
192 unsigned char *p0;
193 bfd_vma addr; /* PC for this arg to be relative to */
194 disassemble_info *info;
195 {
196 int arg_len;
197
198 /* check validity of addressing length */
199 switch (d[1])
200 {
201 case 'b' : arg_len = 1; break;
202 case 'd' : arg_len = 8; break;
203 case 'f' : arg_len = 4; break;
204 case 'g' : arg_len = 8; break;
205 case 'h' : arg_len = 16; break;
206 case 'l' : arg_len = 4; break;
207 case 'o' : arg_len = 16; break;
208 case 'w' : arg_len = 2; break;
209 case 'q' : arg_len = 8; break;
210 default : abort();
211 }
212
213 /* branches have no mode byte */
214 if (d[0] == 'b')
215 {
216 unsigned char *p = p0;
217
218 if (arg_len == 1)
219 (*info->print_address_func) (addr + 1 + NEXTBYTE (p), info);
220 else
221 (*info->print_address_func) (addr + 2 + NEXTWORD (p), info);
222
223 return p - p0;
224 }
225
226 return print_insn_mode (d, arg_len, p0, addr, info);
227 }
228
229 static int
print_insn_mode(d,size,p0,addr,info)230 print_insn_mode (d, size, p0, addr, info)
231 const char *d;
232 int size;
233 unsigned char *p0;
234 bfd_vma addr; /* PC for this arg to be relative to */
235 disassemble_info *info;
236 {
237 unsigned char *p = p0;
238 unsigned char mode, reg;
239
240 /* fetch and interpret mode byte */
241 mode = (unsigned char) NEXTBYTE (p);
242 reg = mode & 0xF;
243 switch (mode & 0xF0)
244 {
245 case 0x00:
246 case 0x10:
247 case 0x20:
248 case 0x30: /* literal mode $number */
249 if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h')
250 (*info->fprintf_func) (info->stream, "$0x%x [%c-float]", mode, d[1]);
251 else
252 (*info->fprintf_func) (info->stream, "$0x%x", mode);
253 break;
254 case 0x40: /* index: base-addr[Rn] */
255 p += print_insn_mode (d, size, p0 + 1, addr + 1, info);
256 (*info->fprintf_func) (info->stream, "[%s]", reg_names[reg]);
257 break;
258 case 0x50: /* register: Rn */
259 (*info->fprintf_func) (info->stream, "%s", reg_names[reg]);
260 break;
261 case 0x60: /* register deferred: (Rn) */
262 (*info->fprintf_func) (info->stream, "(%s)", reg_names[reg]);
263 break;
264 case 0x70: /* autodecrement: -(Rn) */
265 (*info->fprintf_func) (info->stream, "-(%s)", reg_names[reg]);
266 break;
267 case 0x80: /* autoincrement: (Rn)+ */
268 if (reg == 0xF)
269 { /* immediate? */
270 int i;
271
272 FETCH_DATA (info, p + size);
273 (*info->fprintf_func) (info->stream, "$0x");
274 if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h')
275 {
276 int float_word;
277
278 float_word = p[0] | (p[1] << 8);
279 if ((d[1] == 'd' || d[1] == 'f')
280 && (float_word & 0xff80) == 0x8000)
281 {
282 (*info->fprintf_func) (info->stream, "[invalid %c-float]",
283 d[1]);
284 }
285 else
286 {
287 for (i = 0; i < size; i++)
288 (*info->fprintf_func) (info->stream, "%02x",
289 p[size - i - 1]);
290 (*info->fprintf_func) (info->stream, " [%c-float]", d[1]);
291 }
292 }
293 else
294 {
295 for (i = 0; i < size; i++)
296 (*info->fprintf_func) (info->stream, "%02x", p[size - i - 1]);
297 }
298 p += size;
299 }
300 else
301 (*info->fprintf_func) (info->stream, "(%s)+", reg_names[reg]);
302 break;
303 case 0x90: /* autoincrement deferred: @(Rn)+ */
304 if (reg == 0xF)
305 (*info->fprintf_func) (info->stream, "*0x%x", NEXTLONG (p));
306 else
307 (*info->fprintf_func) (info->stream, "@(%s)+", reg_names[reg]);
308 break;
309 case 0xB0: /* displacement byte deferred: *displ(Rn) */
310 (*info->fprintf_func) (info->stream, "*");
311 case 0xA0: /* displacement byte: displ(Rn) */
312 if (reg == 0xF)
313 (*info->print_address_func) (addr + 2 + NEXTBYTE (p), info);
314 else
315 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTBYTE (p),
316 reg_names[reg]);
317 break;
318 case 0xD0: /* displacement word deferred: *displ(Rn) */
319 (*info->fprintf_func) (info->stream, "*");
320 case 0xC0: /* displacement word: displ(Rn) */
321 if (reg == 0xF)
322 (*info->print_address_func) (addr + 3 + NEXTWORD (p), info);
323 else
324 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTWORD (p),
325 reg_names[reg]);
326 break;
327 case 0xF0: /* displacement long deferred: *displ(Rn) */
328 (*info->fprintf_func) (info->stream, "*");
329 case 0xE0: /* displacement long: displ(Rn) */
330 if (reg == 0xF)
331 (*info->print_address_func) (addr + 5 + NEXTLONG (p), info);
332 else
333 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTLONG (p),
334 reg_names[reg]);
335 break;
336 }
337
338 return p - p0;
339 }
340