1 /* Print VAX instructions.
2 Copyright 1995, 1998, 2000, 2001, 2002, 2005
3 Free Software Foundation, Inc.
4 Contributed by Pauline Middelink <middelin@polyware.iaf.nl>
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
19
20 #include "sysdep.h"
21 #include "opcode/vax.h"
22 #include "dis-asm.h"
23
24 /* Local function prototypes */
25 static int fetch_data PARAMS ((struct disassemble_info *, bfd_byte *));
26 static int print_insn_arg
27 PARAMS ((const char *, unsigned char *, bfd_vma, disassemble_info *));
28 static int print_insn_mode
29 PARAMS ((const char *, int, unsigned char *, bfd_vma, disassemble_info *));
30
31
32 static char *reg_names[] =
33 {
34 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
35 "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc"
36 };
37
38 /* Definitions for the function entry mask bits. */
39 static char *entry_mask_bit[] =
40 {
41 /* Registers 0 and 1 shall not be saved, since they're used to pass back
42 a function's result to it's caller... */
43 "~r0~", "~r1~",
44 /* Registers 2 .. 11 are normal registers. */
45 "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11",
46 /* Registers 12 and 13 are argument and frame pointer and must not
47 be saved by using the entry mask. */
48 "~ap~", "~fp~",
49 /* Bits 14 and 15 control integer and decimal overflow. */
50 "IntOvfl", "DecOvfl",
51 };
52
53 /* Sign-extend an (unsigned char). */
54 #if __STDC__ == 1
55 #define COERCE_SIGNED_CHAR(ch) ((signed char)(ch))
56 #else
57 #define COERCE_SIGNED_CHAR(ch) ((int)(((ch) ^ 0x80) & 0xFF) - 128)
58 #endif
59
60 /* Get a 1 byte signed integer. */
61 #define NEXTBYTE(p) \
62 (p += 1, FETCH_DATA (info, p), \
63 COERCE_SIGNED_CHAR(p[-1]))
64
65 /* Get a 2 byte signed integer. */
66 #define COERCE16(x) ((int) (((x) ^ 0x8000) - 0x8000))
67 #define NEXTWORD(p) \
68 (p += 2, FETCH_DATA (info, p), \
69 COERCE16 ((p[-1] << 8) + p[-2]))
70
71 /* Get a 4 byte signed integer. */
72 #define COERCE32(x) ((int) (((x) ^ 0x80000000) - 0x80000000))
73 #define NEXTLONG(p) \
74 (p += 4, FETCH_DATA (info, p), \
75 (COERCE32 ((((((p[-1] << 8) + p[-2]) << 8) + p[-3]) << 8) + p[-4])))
76
77 /* Maximum length of an instruction. */
78 #define MAXLEN 25
79
80 #include <setjmp.h>
81
82 struct private
83 {
84 /* Points to first byte not fetched. */
85 bfd_byte *max_fetched;
86 bfd_byte the_buffer[MAXLEN];
87 bfd_vma insn_start;
88 jmp_buf bailout;
89 };
90
91 /* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive)
92 to ADDR (exclusive) are valid. Returns 1 for success, longjmps
93 on error. */
94 #define FETCH_DATA(info, addr) \
95 ((addr) <= ((struct private *)(info->private_data))->max_fetched \
96 ? 1 : fetch_data ((info), (addr)))
97
98 static int
fetch_data(info,addr)99 fetch_data (info, addr)
100 struct disassemble_info *info;
101 bfd_byte *addr;
102 {
103 int status;
104 struct private *priv = (struct private *) info->private_data;
105 bfd_vma start = priv->insn_start + (priv->max_fetched - priv->the_buffer);
106
107 status = (*info->read_memory_func) (start,
108 priv->max_fetched,
109 addr - priv->max_fetched,
110 info);
111 if (status != 0)
112 {
113 (*info->memory_error_func) (status, start, info);
114 longjmp (priv->bailout, 1);
115 }
116 else
117 priv->max_fetched = addr;
118
119 return 1;
120 }
121
122 /* Print the vax instruction at address MEMADDR in debugged memory,
123 on INFO->STREAM. Returns length of the instruction, in bytes. */
124
125 int
print_insn_vax(memaddr,info)126 print_insn_vax (memaddr, info)
127 bfd_vma memaddr;
128 disassemble_info *info;
129 {
130 const struct vot *votp;
131 const char *argp;
132 unsigned char *arg;
133 struct private priv;
134 bfd_byte *buffer = priv.the_buffer;
135
136 info->private_data = (PTR) &priv;
137 priv.max_fetched = priv.the_buffer;
138 priv.insn_start = memaddr;
139
140 if (setjmp (priv.bailout) != 0)
141 {
142 /* Error return. */
143 return -1;
144 }
145
146 argp = NULL;
147 /* Check if the info buffer has more than one byte left since
148 the last opcode might be a single byte with no argument data. */
149 if (info->buffer_length - (memaddr - info->buffer_vma) > 1)
150 {
151 FETCH_DATA (info, buffer + 2);
152 }
153 else
154 {
155 FETCH_DATA (info, buffer + 1);
156 buffer[1] = 0;
157 }
158
159 /* Decode function entry mask. */
160 if (info->symbols
161 && info->symbols[0]
162 && (info->symbols[0]->flags & BSF_FUNCTION)
163 && memaddr == bfd_asymbol_value (info->symbols[0]))
164 {
165 int i = 0;
166 int register_mask = buffer[1] << 8 | buffer[0];
167
168 (*info->fprintf_func) (info->stream, "Entry mask 0x%04x = <",
169 register_mask);
170
171 for (i = 15; i >= 0; i--)
172 if (register_mask & (1 << i))
173 (*info->fprintf_func) (info->stream, " %s", entry_mask_bit[i]);
174
175 (*info->fprintf_func) (info->stream, " >");
176
177 return 2;
178 }
179
180 for (votp = &votstrs[0]; votp->name[0]; votp++)
181 {
182 register vax_opcodeT opcode = votp->detail.code;
183
184 /* 2 byte codes match 2 buffer pos. */
185 if ((bfd_byte) opcode == buffer[0]
186 && (opcode >> 8 == 0 || opcode >> 8 == buffer[1]))
187 {
188 argp = votp->detail.args;
189 break;
190 }
191 }
192 if (argp == NULL)
193 {
194 /* Handle undefined instructions. */
195 (*info->fprintf_func) (info->stream, ".word 0x%x",
196 (buffer[0] << 8) + buffer[1]);
197 return 2;
198 }
199
200 /* Point at first byte of argument data, and at descriptor for first
201 argument. */
202 arg = buffer + ((votp->detail.code >> 8) ? 2 : 1);
203
204 /* Make sure we have it in mem */
205 FETCH_DATA (info, arg);
206
207 (*info->fprintf_func) (info->stream, "%s", votp->name);
208 if (*argp)
209 (*info->fprintf_func) (info->stream, " ");
210
211 while (*argp)
212 {
213 arg += print_insn_arg (argp, arg, memaddr + arg - buffer, info);
214 argp += 2;
215 if (*argp)
216 (*info->fprintf_func) (info->stream, ",");
217 }
218
219 return arg - buffer;
220 }
221
222 /* Returns number of bytes "eaten" by the operand, or return -1 if an
223 invalid operand was found, or -2 if an opcode tabel error was
224 found. */
225
226 static int
print_insn_arg(d,p0,addr,info)227 print_insn_arg (d, p0, addr, info)
228 const char *d;
229 unsigned char *p0;
230 bfd_vma addr; /* PC for this arg to be relative to */
231 disassemble_info *info;
232 {
233 int arg_len;
234
235 /* check validity of addressing length */
236 switch (d[1])
237 {
238 case 'b' : arg_len = 1; break;
239 case 'd' : arg_len = 8; break;
240 case 'f' : arg_len = 4; break;
241 case 'g' : arg_len = 8; break;
242 case 'h' : arg_len = 16; break;
243 case 'l' : arg_len = 4; break;
244 case 'o' : arg_len = 16; break;
245 case 'w' : arg_len = 2; break;
246 case 'q' : arg_len = 8; break;
247 default : abort();
248 }
249
250 /* branches have no mode byte */
251 if (d[0] == 'b')
252 {
253 unsigned char *p = p0;
254
255 if (arg_len == 1)
256 (*info->print_address_func) (addr + 1 + NEXTBYTE (p), info);
257 else
258 (*info->print_address_func) (addr + 2 + NEXTWORD (p), info);
259
260 return p - p0;
261 }
262
263 return print_insn_mode (d, arg_len, p0, addr, info);
264 }
265
266 static int
print_insn_mode(d,size,p0,addr,info)267 print_insn_mode (d, size, p0, addr, info)
268 const char *d;
269 int size;
270 unsigned char *p0;
271 bfd_vma addr; /* PC for this arg to be relative to */
272 disassemble_info *info;
273 {
274 unsigned char *p = p0;
275 unsigned char mode, reg;
276
277 /* fetch and interpret mode byte */
278 mode = (unsigned char) NEXTBYTE (p);
279 reg = mode & 0xF;
280 switch (mode & 0xF0)
281 {
282 case 0x00:
283 case 0x10:
284 case 0x20:
285 case 0x30: /* literal mode $number */
286 if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h')
287 (*info->fprintf_func) (info->stream, "$0x%x [%c-float]", mode, d[1]);
288 else
289 (*info->fprintf_func) (info->stream, "$0x%x", mode);
290 break;
291 case 0x40: /* index: base-addr[Rn] */
292 p += print_insn_mode (d, size, p0 + 1, addr + 1, info);
293 (*info->fprintf_func) (info->stream, "[%s]", reg_names[reg]);
294 break;
295 case 0x50: /* register: Rn */
296 (*info->fprintf_func) (info->stream, "%s", reg_names[reg]);
297 break;
298 case 0x60: /* register deferred: (Rn) */
299 (*info->fprintf_func) (info->stream, "(%s)", reg_names[reg]);
300 break;
301 case 0x70: /* autodecrement: -(Rn) */
302 (*info->fprintf_func) (info->stream, "-(%s)", reg_names[reg]);
303 break;
304 case 0x80: /* autoincrement: (Rn)+ */
305 if (reg == 0xF)
306 { /* immediate? */
307 int i;
308
309 FETCH_DATA (info, p + size);
310 (*info->fprintf_func) (info->stream, "$0x");
311 if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h')
312 {
313 int float_word;
314
315 float_word = p[0] | (p[1] << 8);
316 if ((d[1] == 'd' || d[1] == 'f')
317 && (float_word & 0xff80) == 0x8000)
318 {
319 (*info->fprintf_func) (info->stream, "[invalid %c-float]",
320 d[1]);
321 }
322 else
323 {
324 for (i = 0; i < size; i++)
325 (*info->fprintf_func) (info->stream, "%02x",
326 p[size - i - 1]);
327 (*info->fprintf_func) (info->stream, " [%c-float]", d[1]);
328 }
329 }
330 else
331 {
332 for (i = 0; i < size; i++)
333 (*info->fprintf_func) (info->stream, "%02x", p[size - i - 1]);
334 }
335 p += size;
336 }
337 else
338 (*info->fprintf_func) (info->stream, "(%s)+", reg_names[reg]);
339 break;
340 case 0x90: /* autoincrement deferred: @(Rn)+ */
341 if (reg == 0xF)
342 (*info->fprintf_func) (info->stream, "*0x%x", NEXTLONG (p));
343 else
344 (*info->fprintf_func) (info->stream, "@(%s)+", reg_names[reg]);
345 break;
346 case 0xB0: /* displacement byte deferred: *displ(Rn) */
347 (*info->fprintf_func) (info->stream, "*");
348 case 0xA0: /* displacement byte: displ(Rn) */
349 if (reg == 0xF)
350 (*info->print_address_func) (addr + 2 + NEXTBYTE (p), info);
351 else
352 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTBYTE (p),
353 reg_names[reg]);
354 break;
355 case 0xD0: /* displacement word deferred: *displ(Rn) */
356 (*info->fprintf_func) (info->stream, "*");
357 case 0xC0: /* displacement word: displ(Rn) */
358 if (reg == 0xF)
359 (*info->print_address_func) (addr + 3 + NEXTWORD (p), info);
360 else
361 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTWORD (p),
362 reg_names[reg]);
363 break;
364 case 0xF0: /* displacement long deferred: *displ(Rn) */
365 (*info->fprintf_func) (info->stream, "*");
366 case 0xE0: /* displacement long: displ(Rn) */
367 if (reg == 0xF)
368 (*info->print_address_func) (addr + 5 + NEXTLONG (p), info);
369 else
370 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTLONG (p),
371 reg_names[reg]);
372 break;
373 }
374
375 return p - p0;
376 }
377