1 /* xtensa-dis.c. Disassembly functions for Xtensa.
2 Copyright (C) 2003-2021 Free Software Foundation, Inc.
3 Contributed by Bob Wilson at Tensilica, Inc. (bwilson@tensilica.com)
4
5 This file is part of the GNU opcodes library.
6
7 This library is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11
12 It is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
15 License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this file; see the file COPYING. If not, write to the
19 Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston,
20 MA 02110-1301, USA. */
21
22 #include "sysdep.h"
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <sys/types.h>
26 #include <string.h>
27 #include "xtensa-isa.h"
28 #include "ansidecl.h"
29 #include "libiberty.h"
30 #include "bfd.h"
31 #include "elf/xtensa.h"
32 #include "disassemble.h"
33
34 #include <setjmp.h>
35
36 extern xtensa_isa xtensa_default_isa;
37
38 #ifndef MAX
39 #define MAX(a,b) (a > b ? a : b)
40 #endif
41
42 int show_raw_fields;
43
44 struct dis_private
45 {
46 bfd_byte *byte_buf;
47 OPCODES_SIGJMP_BUF bailout;
48 /* Persistent fields, valid for last_section only. */
49 asection *last_section;
50 property_table_entry *insn_table_entries;
51 int insn_table_entry_count;
52 /* Cached property table search position. */
53 bfd_vma insn_table_cur_addr;
54 int insn_table_cur_idx;
55 };
56
57 static void
xtensa_coalesce_insn_tables(struct dis_private * priv)58 xtensa_coalesce_insn_tables (struct dis_private *priv)
59 {
60 const int mask = ~(XTENSA_PROP_DATA | XTENSA_PROP_NO_TRANSFORM);
61 int count = priv->insn_table_entry_count;
62 int i, j;
63
64 /* Loop over all entries, combining adjacent ones that differ only in
65 the flag bits XTENSA_PROP_DATA and XTENSA_PROP_NO_TRANSFORM. */
66
67 for (i = j = 0; j < count; ++i)
68 {
69 property_table_entry *entry = priv->insn_table_entries + i;
70
71 *entry = priv->insn_table_entries[j];
72
73 for (++j; j < count; ++j)
74 {
75 property_table_entry *next = priv->insn_table_entries + j;
76 int fill = xtensa_compute_fill_extra_space (entry);
77 int size = entry->size + fill;
78
79 if (entry->address + size == next->address)
80 {
81 int entry_flags = entry->flags & mask;
82 int next_flags = next->flags & mask;
83
84 if (next_flags == entry_flags)
85 entry->size = next->address - entry->address + next->size;
86 else
87 break;
88 }
89 else
90 {
91 break;
92 }
93 }
94 }
95 priv->insn_table_entry_count = i;
96 }
97
98 static property_table_entry *
xtensa_find_table_entry(bfd_vma memaddr,struct disassemble_info * info)99 xtensa_find_table_entry (bfd_vma memaddr, struct disassemble_info *info)
100 {
101 struct dis_private *priv = (struct dis_private *) info->private_data;
102 int i;
103
104 if (priv->insn_table_entries == NULL
105 || priv->insn_table_entry_count < 0)
106 return NULL;
107
108 if (memaddr < priv->insn_table_cur_addr)
109 priv->insn_table_cur_idx = 0;
110
111 for (i = priv->insn_table_cur_idx; i < priv->insn_table_entry_count; ++i)
112 {
113 property_table_entry *block = priv->insn_table_entries + i;
114
115 if (block->size != 0)
116 {
117 if ((memaddr >= block->address
118 && memaddr < block->address + block->size)
119 || memaddr < block->address)
120 {
121 priv->insn_table_cur_addr = memaddr;
122 priv->insn_table_cur_idx = i;
123 return block;
124 }
125 }
126 }
127 return NULL;
128 }
129
130 /* Check whether an instruction crosses an instruction block boundary
131 (according to property tables).
132 If it does, return 0 (doesn't fit), else return 1. */
133
134 static int
xtensa_instruction_fits(bfd_vma memaddr,int size,property_table_entry * insn_block)135 xtensa_instruction_fits (bfd_vma memaddr, int size,
136 property_table_entry *insn_block)
137 {
138 unsigned max_size;
139
140 /* If no property table info, assume it fits. */
141 if (insn_block == NULL || size <= 0)
142 return 1;
143
144 /* If too high, limit nextstop by the next insn address. */
145 if (insn_block->address > memaddr)
146 {
147 /* memaddr is not in an instruction block, but is followed by one. */
148 max_size = insn_block->address - memaddr;
149 }
150 else
151 {
152 /* memaddr is in an instruction block, go no further than the end. */
153 max_size = insn_block->address + insn_block->size - memaddr;
154 }
155
156 /* Crossing a boundary, doesn't "fit". */
157 if ((unsigned)size > max_size)
158 return 0;
159 return 1;
160 }
161
162 static int
fetch_data(struct disassemble_info * info,bfd_vma memaddr)163 fetch_data (struct disassemble_info *info, bfd_vma memaddr)
164 {
165 int length, status = 0;
166 struct dis_private *priv = (struct dis_private *) info->private_data;
167 int insn_size = xtensa_isa_maxlength (xtensa_default_isa);
168
169 insn_size = MAX (insn_size, 4);
170
171 /* Read the maximum instruction size, padding with zeros if we go past
172 the end of the text section. This code will automatically adjust
173 length when we hit the end of the buffer. */
174
175 memset (priv->byte_buf, 0, insn_size);
176 for (length = insn_size; length > 0; length--)
177 {
178 status = (*info->read_memory_func) (memaddr, priv->byte_buf, length,
179 info);
180 if (status == 0)
181 return length;
182 }
183 (*info->memory_error_func) (status, memaddr, info);
184 OPCODES_SIGLONGJMP (priv->bailout, 1);
185 /*NOTREACHED*/
186 }
187
188
189 static void
print_xtensa_operand(bfd_vma memaddr,struct disassemble_info * info,xtensa_opcode opc,int opnd,unsigned operand_val)190 print_xtensa_operand (bfd_vma memaddr,
191 struct disassemble_info *info,
192 xtensa_opcode opc,
193 int opnd,
194 unsigned operand_val)
195 {
196 xtensa_isa isa = xtensa_default_isa;
197 int signed_operand_val, status;
198 bfd_byte litbuf[4];
199
200 if (show_raw_fields)
201 {
202 if (operand_val < 0xa)
203 (*info->fprintf_func) (info->stream, "%u", operand_val);
204 else
205 (*info->fprintf_func) (info->stream, "0x%x", operand_val);
206 return;
207 }
208
209 (void) xtensa_operand_decode (isa, opc, opnd, &operand_val);
210 signed_operand_val = (int) operand_val;
211
212 if (xtensa_operand_is_register (isa, opc, opnd) == 0)
213 {
214 if (xtensa_operand_is_PCrelative (isa, opc, opnd) == 1)
215 {
216 (void) xtensa_operand_undo_reloc (isa, opc, opnd,
217 &operand_val, memaddr);
218 info->target = operand_val;
219 (*info->print_address_func) (info->target, info);
220 /* Also display value loaded by L32R (but not if reloc exists,
221 those tend to be wrong): */
222 if ((info->flags & INSN_HAS_RELOC) == 0
223 && !strcmp ("l32r", xtensa_opcode_name (isa, opc)))
224 status = (*info->read_memory_func) (operand_val, litbuf, 4, info);
225 else
226 status = -1;
227
228 if (status == 0)
229 {
230 unsigned literal = bfd_get_bits (litbuf, 32,
231 info->endian == BFD_ENDIAN_BIG);
232
233 (*info->fprintf_func) (info->stream, " (");
234 (*info->print_address_func) (literal, info);
235 (*info->fprintf_func) (info->stream, ")");
236 }
237 }
238 else
239 {
240 if ((signed_operand_val > -256) && (signed_operand_val < 256))
241 (*info->fprintf_func) (info->stream, "%d", signed_operand_val);
242 else
243 (*info->fprintf_func) (info->stream, "0x%x", signed_operand_val);
244 }
245 }
246 else
247 {
248 int i = 1;
249 xtensa_regfile opnd_rf = xtensa_operand_regfile (isa, opc, opnd);
250 (*info->fprintf_func) (info->stream, "%s%u",
251 xtensa_regfile_shortname (isa, opnd_rf),
252 operand_val);
253 while (i < xtensa_operand_num_regs (isa, opc, opnd))
254 {
255 operand_val++;
256 (*info->fprintf_func) (info->stream, ":%s%u",
257 xtensa_regfile_shortname (isa, opnd_rf),
258 operand_val);
259 i++;
260 }
261 }
262 }
263
264
265 /* Print the Xtensa instruction at address MEMADDR on info->stream.
266 Returns length of the instruction in bytes. */
267
268 int
print_insn_xtensa(bfd_vma memaddr,struct disassemble_info * info)269 print_insn_xtensa (bfd_vma memaddr, struct disassemble_info *info)
270 {
271 unsigned operand_val;
272 int bytes_fetched, size, maxsize, i, n, noperands, nslots;
273 xtensa_isa isa;
274 xtensa_opcode opc;
275 xtensa_format fmt;
276 static struct dis_private priv;
277 static bfd_byte *byte_buf = NULL;
278 static xtensa_insnbuf insn_buffer = NULL;
279 static xtensa_insnbuf slot_buffer = NULL;
280 int first, first_slot, valid_insn;
281 property_table_entry *insn_block;
282
283 if (!xtensa_default_isa)
284 xtensa_default_isa = xtensa_isa_init (0, 0);
285
286 info->target = 0;
287 maxsize = xtensa_isa_maxlength (xtensa_default_isa);
288
289 /* Set bytes_per_line to control the amount of whitespace between the hex
290 values and the opcode. For Xtensa, we always print one "chunk" and we
291 vary bytes_per_chunk to determine how many bytes to print. (objdump
292 would apparently prefer that we set bytes_per_chunk to 1 and vary
293 bytes_per_line but that makes it hard to fit 64-bit instructions on
294 an 80-column screen.) The value of bytes_per_line here is not exactly
295 right, because objdump adds an extra space for each chunk so that the
296 amount of whitespace depends on the chunk size. Oh well, it's good
297 enough.... Note that we set the minimum size to 4 to accomodate
298 literal pools. */
299 info->bytes_per_line = MAX (maxsize, 4);
300
301 /* Allocate buffers the first time through. */
302 if (!insn_buffer)
303 {
304 insn_buffer = xtensa_insnbuf_alloc (xtensa_default_isa);
305 slot_buffer = xtensa_insnbuf_alloc (xtensa_default_isa);
306 byte_buf = (bfd_byte *) xmalloc (MAX (maxsize, 4));
307 }
308
309 priv.byte_buf = byte_buf;
310
311 info->private_data = (void *) &priv;
312
313 /* Prepare instruction tables. */
314
315 if (info->section != NULL)
316 {
317 asection *section = info->section;
318
319 if (priv.last_section != section)
320 {
321 bfd *abfd = section->owner;
322
323 if (priv.last_section != NULL)
324 {
325 /* Reset insn_table_entries. */
326 priv.insn_table_entry_count = 0;
327 free (priv.insn_table_entries);
328 priv.insn_table_entries = NULL;
329 }
330 priv.last_section = section;
331
332 /* Read insn_table_entries. */
333 priv.insn_table_entry_count =
334 xtensa_read_table_entries (abfd, section,
335 &priv.insn_table_entries,
336 XTENSA_PROP_SEC_NAME, false);
337 if (priv.insn_table_entry_count == 0)
338 {
339 free (priv.insn_table_entries);
340 priv.insn_table_entries = NULL;
341 /* Backwards compatibility support. */
342 priv.insn_table_entry_count =
343 xtensa_read_table_entries (abfd, section,
344 &priv.insn_table_entries,
345 XTENSA_INSN_SEC_NAME, false);
346 }
347 priv.insn_table_cur_idx = 0;
348 xtensa_coalesce_insn_tables (&priv);
349 }
350 /* Else nothing to do, same section as last time. */
351 }
352
353 if (OPCODES_SIGSETJMP (priv.bailout) != 0)
354 /* Error return. */
355 return -1;
356
357 /* Fetch the maximum size instruction. */
358 bytes_fetched = fetch_data (info, memaddr);
359
360 insn_block = xtensa_find_table_entry (memaddr, info);
361
362 /* Don't set "isa" before the setjmp to keep the compiler from griping. */
363 isa = xtensa_default_isa;
364 size = 0;
365 nslots = 0;
366 valid_insn = 0;
367 fmt = 0;
368 if (!insn_block || (insn_block->flags & XTENSA_PROP_INSN))
369 {
370 /* Copy the bytes into the decode buffer. */
371 memset (insn_buffer, 0, (xtensa_insnbuf_size (isa) *
372 sizeof (xtensa_insnbuf_word)));
373 xtensa_insnbuf_from_chars (isa, insn_buffer, priv.byte_buf,
374 bytes_fetched);
375
376 fmt = xtensa_format_decode (isa, insn_buffer);
377 if (fmt != XTENSA_UNDEFINED
378 && ((size = xtensa_format_length (isa, fmt)) <= bytes_fetched)
379 && xtensa_instruction_fits (memaddr, size, insn_block))
380 {
381 /* Make sure all the opcodes are valid. */
382 valid_insn = 1;
383 nslots = xtensa_format_num_slots (isa, fmt);
384 for (n = 0; n < nslots; n++)
385 {
386 xtensa_format_get_slot (isa, fmt, n, insn_buffer, slot_buffer);
387 if (xtensa_opcode_decode (isa, fmt, n, slot_buffer)
388 == XTENSA_UNDEFINED)
389 {
390 valid_insn = 0;
391 break;
392 }
393 }
394 }
395 }
396
397 if (!valid_insn)
398 {
399 if (insn_block && (insn_block->flags & XTENSA_PROP_LITERAL)
400 && (memaddr & 3) == 0 && bytes_fetched >= 4)
401 {
402 info->bytes_per_chunk = 4;
403 return 4;
404 }
405 else
406 {
407 (*info->fprintf_func) (info->stream, ".byte %#02x", priv.byte_buf[0]);
408 return 1;
409 }
410 }
411
412 if (nslots > 1)
413 (*info->fprintf_func) (info->stream, "{ ");
414
415 info->insn_type = dis_nonbranch;
416 info->insn_info_valid = 1;
417
418 first_slot = 1;
419 for (n = 0; n < nslots; n++)
420 {
421 if (first_slot)
422 first_slot = 0;
423 else
424 (*info->fprintf_func) (info->stream, "; ");
425
426 xtensa_format_get_slot (isa, fmt, n, insn_buffer, slot_buffer);
427 opc = xtensa_opcode_decode (isa, fmt, n, slot_buffer);
428 (*info->fprintf_func) (info->stream, "%s",
429 xtensa_opcode_name (isa, opc));
430
431 if (xtensa_opcode_is_branch (isa, opc))
432 info->insn_type = dis_condbranch;
433 else if (xtensa_opcode_is_jump (isa, opc))
434 info->insn_type = dis_branch;
435 else if (xtensa_opcode_is_call (isa, opc))
436 info->insn_type = dis_jsr;
437
438 /* Print the operands (if any). */
439 noperands = xtensa_opcode_num_operands (isa, opc);
440 first = 1;
441 for (i = 0; i < noperands; i++)
442 {
443 if (xtensa_operand_is_visible (isa, opc, i) == 0)
444 continue;
445 if (first)
446 {
447 (*info->fprintf_func) (info->stream, "\t");
448 first = 0;
449 }
450 else
451 (*info->fprintf_func) (info->stream, ", ");
452 (void) xtensa_operand_get_field (isa, opc, i, fmt, n,
453 slot_buffer, &operand_val);
454
455 print_xtensa_operand (memaddr, info, opc, i, operand_val);
456 }
457 }
458
459 if (nslots > 1)
460 (*info->fprintf_func) (info->stream, " }");
461
462 info->bytes_per_chunk = size;
463 info->display_endian = info->endian;
464
465 return size;
466 }
467
468