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36591ba1 | 1 | /* Altera Nios II disassemble routines |
4b95cf5c | 2 | Copyright (C) 2012-2014 Free Software Foundation, Inc. |
36591ba1 SL |
3 | Contributed by Nigel Gray (ngray@altera.com). |
4 | Contributed by Mentor Graphics, Inc. | |
5 | ||
6 | This file is part of the GNU opcodes library. | |
7 | ||
8 | This library is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3, or (at your option) | |
11 | any later version. | |
12 | ||
13 | It is distributed in the hope that it will be useful, but WITHOUT | |
14 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
15 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
16 | License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this file; see the file COPYING. If not, write to the | |
20 | Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, | |
21 | MA 02110-1301, USA. */ | |
22 | ||
23 | #include "sysdep.h" | |
24 | #include "dis-asm.h" | |
25 | #include "opcode/nios2.h" | |
26 | #include "libiberty.h" | |
27 | #include <string.h> | |
28 | #include <assert.h> | |
29 | ||
30 | /* No symbol table is available when this code runs out in an embedded | |
31 | system as when it is used for disassembler support in a monitor. */ | |
32 | #if !defined(EMBEDDED_ENV) | |
33 | #define SYMTAB_AVAILABLE 1 | |
34 | #include "elf-bfd.h" | |
35 | #include "elf/nios2.h" | |
36 | #endif | |
37 | ||
38 | /* Length of Nios II instruction in bytes. */ | |
39 | #define INSNLEN 4 | |
40 | ||
41 | /* Data structures used by the opcode hash table. */ | |
42 | typedef struct _nios2_opcode_hash | |
43 | { | |
44 | const struct nios2_opcode *opcode; | |
45 | struct _nios2_opcode_hash *next; | |
46 | } nios2_opcode_hash; | |
47 | ||
48 | static bfd_boolean nios2_hash_init = 0; | |
49 | static nios2_opcode_hash *nios2_hash[(OP_MASK_OP) + 1]; | |
50 | ||
51 | /* Separate hash table for pseudo-ops. */ | |
52 | static nios2_opcode_hash *nios2_ps_hash[(OP_MASK_OP) + 1]; | |
53 | ||
54 | /* Function to initialize the opcode hash table. */ | |
55 | static void | |
56 | nios2_init_opcode_hash (void) | |
57 | { | |
58 | unsigned int i; | |
59 | register const struct nios2_opcode *op; | |
60 | ||
61 | for (i = 0; i <= OP_MASK_OP; ++i) | |
62 | nios2_hash[0] = NULL; | |
63 | for (i = 0; i <= OP_MASK_OP; i++) | |
64 | for (op = nios2_opcodes; op < &nios2_opcodes[NUMOPCODES]; op++) | |
65 | { | |
66 | nios2_opcode_hash *new_hash; | |
67 | nios2_opcode_hash **bucket = NULL; | |
68 | ||
69 | if ((op->pinfo & NIOS2_INSN_MACRO) == NIOS2_INSN_MACRO) | |
70 | { | |
71 | if (i == ((op->match >> OP_SH_OP) & OP_MASK_OP) | |
72 | && (op->pinfo & (NIOS2_INSN_MACRO_MOV | NIOS2_INSN_MACRO_MOVI) | |
73 | & 0x7fffffff)) | |
74 | bucket = &(nios2_ps_hash[i]); | |
75 | } | |
76 | else if (i == ((op->match >> OP_SH_OP) & OP_MASK_OP)) | |
77 | bucket = &(nios2_hash[i]); | |
78 | ||
79 | if (bucket) | |
80 | { | |
81 | new_hash = | |
82 | (nios2_opcode_hash *) malloc (sizeof (nios2_opcode_hash)); | |
83 | if (new_hash == NULL) | |
84 | { | |
85 | fprintf (stderr, | |
86 | "error allocating memory...broken disassembler\n"); | |
87 | abort (); | |
88 | } | |
89 | new_hash->opcode = op; | |
90 | new_hash->next = NULL; | |
91 | while (*bucket) | |
92 | bucket = &((*bucket)->next); | |
93 | *bucket = new_hash; | |
94 | } | |
95 | } | |
96 | nios2_hash_init = 1; | |
97 | #ifdef DEBUG_HASHTABLE | |
98 | for (i = 0; i <= OP_MASK_OP; ++i) | |
99 | { | |
100 | nios2_opcode_hash *tmp_hash = nios2_hash[i]; | |
101 | printf ("index: 0x%02X ops: ", i); | |
102 | while (tmp_hash != NULL) | |
103 | { | |
104 | printf ("%s ", tmp_hash->opcode->name); | |
105 | tmp_hash = tmp_hash->next; | |
106 | } | |
107 | printf ("\n"); | |
108 | } | |
109 | ||
110 | for (i = 0; i <= OP_MASK_OP; ++i) | |
111 | { | |
112 | nios2_opcode_hash *tmp_hash = nios2_ps_hash[i]; | |
113 | printf ("index: 0x%02X ops: ", i); | |
114 | while (tmp_hash != NULL) | |
115 | { | |
116 | printf ("%s ", tmp_hash->opcode->name); | |
117 | tmp_hash = tmp_hash->next; | |
118 | } | |
119 | printf ("\n"); | |
120 | } | |
121 | #endif /* DEBUG_HASHTABLE */ | |
122 | } | |
123 | ||
124 | /* Return a pointer to an nios2_opcode struct for a given instruction | |
125 | opcode, or NULL if there is an error. */ | |
126 | const struct nios2_opcode * | |
127 | nios2_find_opcode_hash (unsigned long opcode) | |
128 | { | |
129 | nios2_opcode_hash *entry; | |
130 | ||
131 | /* Build a hash table to shorten the search time. */ | |
132 | if (!nios2_hash_init) | |
133 | nios2_init_opcode_hash (); | |
134 | ||
135 | /* First look in the pseudo-op hashtable. */ | |
136 | for (entry = nios2_ps_hash[(opcode >> OP_SH_OP) & OP_MASK_OP]; | |
137 | entry; entry = entry->next) | |
138 | if (entry->opcode->match == (opcode & entry->opcode->mask)) | |
139 | return entry->opcode; | |
140 | ||
141 | /* Otherwise look in the main hashtable. */ | |
142 | for (entry = nios2_hash[(opcode >> OP_SH_OP) & OP_MASK_OP]; | |
143 | entry; entry = entry->next) | |
144 | if (entry->opcode->match == (opcode & entry->opcode->mask)) | |
145 | return entry->opcode; | |
146 | ||
147 | return NULL; | |
148 | } | |
149 | ||
150 | /* There are 32 regular registers, 32 coprocessor registers, | |
151 | and 32 control registers. */ | |
152 | #define NUMREGNAMES 32 | |
153 | ||
154 | /* Return a pointer to the base of the coprocessor register name array. */ | |
155 | static struct nios2_reg * | |
156 | nios2_coprocessor_regs (void) | |
157 | { | |
158 | static struct nios2_reg *cached = NULL; | |
159 | ||
160 | if (!cached) | |
161 | { | |
162 | int i; | |
163 | for (i = NUMREGNAMES; i < nios2_num_regs; i++) | |
164 | if (!strcmp (nios2_regs[i].name, "c0")) | |
165 | { | |
166 | cached = nios2_regs + i; | |
167 | break; | |
168 | } | |
169 | assert (cached); | |
170 | } | |
171 | return cached; | |
172 | } | |
173 | ||
174 | /* Return a pointer to the base of the control register name array. */ | |
175 | static struct nios2_reg * | |
176 | nios2_control_regs (void) | |
177 | { | |
178 | static struct nios2_reg *cached = NULL; | |
179 | ||
180 | if (!cached) | |
181 | { | |
182 | int i; | |
183 | for (i = NUMREGNAMES; i < nios2_num_regs; i++) | |
184 | if (!strcmp (nios2_regs[i].name, "status")) | |
185 | { | |
186 | cached = nios2_regs + i; | |
187 | break; | |
188 | } | |
189 | assert (cached); | |
190 | } | |
191 | return cached; | |
192 | } | |
193 | ||
194 | /* The function nios2_print_insn_arg uses the character pointed | |
195 | to by ARGPTR to determine how it print the next token or separator | |
196 | character in the arguments to an instruction. */ | |
197 | static int | |
198 | nios2_print_insn_arg (const char *argptr, | |
199 | unsigned long opcode, bfd_vma address, | |
200 | disassemble_info *info) | |
201 | { | |
202 | unsigned long i = 0; | |
203 | struct nios2_reg *reg_base; | |
204 | ||
205 | switch (*argptr) | |
206 | { | |
207 | case ',': | |
208 | case '(': | |
209 | case ')': | |
210 | (*info->fprintf_func) (info->stream, "%c", *argptr); | |
211 | break; | |
212 | case 'd': | |
213 | i = GET_INSN_FIELD (RRD, opcode); | |
214 | ||
215 | if (GET_INSN_FIELD (OP, opcode) == OP_MATCH_CUSTOM | |
216 | && GET_INSN_FIELD (CUSTOM_C, opcode) == 0) | |
217 | reg_base = nios2_coprocessor_regs (); | |
218 | else | |
219 | reg_base = nios2_regs; | |
220 | ||
221 | if (i < NUMREGNAMES) | |
222 | (*info->fprintf_func) (info->stream, "%s", reg_base[i].name); | |
223 | else | |
224 | (*info->fprintf_func) (info->stream, "unknown"); | |
225 | break; | |
226 | case 's': | |
227 | i = GET_INSN_FIELD (RRS, opcode); | |
228 | ||
229 | if (GET_INSN_FIELD (OP, opcode) == OP_MATCH_CUSTOM | |
230 | && GET_INSN_FIELD (CUSTOM_A, opcode) == 0) | |
231 | reg_base = nios2_coprocessor_regs (); | |
232 | else | |
233 | reg_base = nios2_regs; | |
234 | ||
235 | if (i < NUMREGNAMES) | |
236 | (*info->fprintf_func) (info->stream, "%s", reg_base[i].name); | |
237 | else | |
238 | (*info->fprintf_func) (info->stream, "unknown"); | |
239 | break; | |
240 | case 't': | |
241 | i = GET_INSN_FIELD (RRT, opcode); | |
242 | ||
243 | if (GET_INSN_FIELD (OP, opcode) == OP_MATCH_CUSTOM | |
244 | && GET_INSN_FIELD (CUSTOM_B, opcode) == 0) | |
245 | reg_base = nios2_coprocessor_regs (); | |
246 | else | |
247 | reg_base = nios2_regs; | |
248 | ||
249 | if (i < NUMREGNAMES) | |
250 | (*info->fprintf_func) (info->stream, "%s", reg_base[i].name); | |
251 | else | |
252 | (*info->fprintf_func) (info->stream, "unknown"); | |
253 | break; | |
254 | case 'i': | |
255 | /* 16-bit signed immediate. */ | |
256 | i = (signed) (GET_INSN_FIELD (IMM16, opcode) << 16) >> 16; | |
257 | (*info->fprintf_func) (info->stream, "%ld", i); | |
258 | break; | |
259 | case 'u': | |
260 | /* 16-bit unsigned immediate. */ | |
261 | i = GET_INSN_FIELD (IMM16, opcode); | |
262 | (*info->fprintf_func) (info->stream, "%ld", i); | |
263 | break; | |
264 | case 'o': | |
265 | /* 16-bit signed immediate address offset. */ | |
266 | i = (signed) (GET_INSN_FIELD (IMM16, opcode) << 16) >> 16; | |
267 | address = address + 4 + i; | |
268 | (*info->print_address_func) (address, info); | |
269 | break; | |
270 | case 'p': | |
271 | /* 5-bit unsigned immediate. */ | |
272 | i = GET_INSN_FIELD (CACHE_OPX, opcode); | |
273 | (*info->fprintf_func) (info->stream, "%ld", i); | |
274 | break; | |
275 | case 'j': | |
276 | /* 5-bit unsigned immediate. */ | |
277 | i = GET_INSN_FIELD (IMM5, opcode); | |
278 | (*info->fprintf_func) (info->stream, "%ld", i); | |
279 | break; | |
280 | case 'l': | |
281 | /* 8-bit unsigned immediate. */ | |
282 | /* FIXME - not yet implemented */ | |
283 | i = GET_INSN_FIELD (CUSTOM_N, opcode); | |
284 | (*info->fprintf_func) (info->stream, "%lu", i); | |
285 | break; | |
286 | case 'm': | |
287 | /* 26-bit unsigned immediate. */ | |
288 | i = GET_INSN_FIELD (IMM26, opcode); | |
289 | /* This translates to an address because it's only used in call | |
290 | instructions. */ | |
291 | address = (address & 0xf0000000) | (i << 2); | |
292 | (*info->print_address_func) (address, info); | |
293 | break; | |
294 | case 'c': | |
295 | /* Control register index. */ | |
296 | i = GET_INSN_FIELD (IMM5, opcode); | |
297 | reg_base = nios2_control_regs (); | |
298 | (*info->fprintf_func) (info->stream, "%s", reg_base[i].name); | |
299 | break; | |
300 | case 'b': | |
301 | i = GET_INSN_FIELD (IMM5, opcode); | |
302 | (*info->fprintf_func) (info->stream, "%ld", i); | |
303 | break; | |
304 | default: | |
305 | (*info->fprintf_func) (info->stream, "unknown"); | |
306 | break; | |
307 | } | |
308 | return 0; | |
309 | } | |
310 | ||
311 | /* nios2_disassemble does all the work of disassembling a Nios II | |
312 | instruction opcode. */ | |
313 | static int | |
314 | nios2_disassemble (bfd_vma address, unsigned long opcode, | |
315 | disassemble_info *info) | |
316 | { | |
317 | const struct nios2_opcode *op; | |
318 | ||
319 | info->bytes_per_line = INSNLEN; | |
320 | info->bytes_per_chunk = INSNLEN; | |
321 | info->display_endian = info->endian; | |
322 | info->insn_info_valid = 1; | |
323 | info->branch_delay_insns = 0; | |
324 | info->data_size = 0; | |
325 | info->insn_type = dis_nonbranch; | |
326 | info->target = 0; | |
327 | info->target2 = 0; | |
328 | ||
329 | /* Find the major opcode and use this to disassemble | |
330 | the instruction and its arguments. */ | |
331 | op = nios2_find_opcode_hash (opcode); | |
332 | ||
333 | if (op != NULL) | |
334 | { | |
335 | bfd_boolean is_nop = FALSE; | |
336 | if (op->pinfo == NIOS2_INSN_MACRO_MOV) | |
337 | { | |
338 | /* Check for mov r0, r0 and change to nop. */ | |
339 | int dst, src; | |
340 | dst = GET_INSN_FIELD (RRD, opcode); | |
341 | src = GET_INSN_FIELD (RRS, opcode); | |
342 | if (dst == 0 && src == 0) | |
343 | { | |
344 | (*info->fprintf_func) (info->stream, "nop"); | |
345 | is_nop = TRUE; | |
346 | } | |
347 | else | |
348 | (*info->fprintf_func) (info->stream, "%s", op->name); | |
349 | } | |
350 | else | |
351 | (*info->fprintf_func) (info->stream, "%s", op->name); | |
352 | ||
353 | if (!is_nop) | |
354 | { | |
355 | const char *argstr = op->args; | |
356 | if (argstr != NULL && *argstr != '\0') | |
357 | { | |
358 | (*info->fprintf_func) (info->stream, "\t"); | |
359 | while (*argstr != '\0') | |
360 | { | |
361 | nios2_print_insn_arg (argstr, opcode, address, info); | |
362 | ++argstr; | |
363 | } | |
364 | } | |
365 | } | |
366 | } | |
367 | else | |
368 | { | |
369 | /* Handle undefined instructions. */ | |
370 | info->insn_type = dis_noninsn; | |
371 | (*info->fprintf_func) (info->stream, "0x%lx", opcode); | |
372 | } | |
373 | /* Tell the caller how far to advance the program counter. */ | |
374 | return INSNLEN; | |
375 | } | |
376 | ||
377 | ||
378 | /* print_insn_nios2 is the main disassemble function for Nios II. | |
379 | The function diassembler(abfd) (source in disassemble.c) returns a | |
380 | pointer to this either print_insn_big_nios2 or | |
381 | print_insn_little_nios2, which in turn call this function when the | |
382 | bfd machine type is Nios II. print_insn_nios2 reads the | |
383 | instruction word at the address given, and prints the disassembled | |
384 | instruction on the stream info->stream using info->fprintf_func. */ | |
385 | ||
386 | static int | |
387 | print_insn_nios2 (bfd_vma address, disassemble_info *info, | |
388 | enum bfd_endian endianness) | |
389 | { | |
390 | bfd_byte buffer[INSNLEN]; | |
391 | int status; | |
392 | ||
393 | status = (*info->read_memory_func) (address, buffer, INSNLEN, info); | |
394 | if (status == 0) | |
395 | { | |
396 | unsigned long insn; | |
397 | if (endianness == BFD_ENDIAN_BIG) | |
398 | insn = (unsigned long) bfd_getb32 (buffer); | |
399 | else | |
400 | insn = (unsigned long) bfd_getl32 (buffer); | |
401 | status = nios2_disassemble (address, insn, info); | |
402 | } | |
403 | else | |
404 | { | |
405 | (*info->memory_error_func) (status, address, info); | |
406 | status = -1; | |
407 | } | |
408 | return status; | |
409 | } | |
410 | ||
411 | /* These two functions are the main entry points, accessed from | |
412 | disassemble.c. */ | |
413 | int | |
414 | print_insn_big_nios2 (bfd_vma address, disassemble_info *info) | |
415 | { | |
416 | return print_insn_nios2 (address, info, BFD_ENDIAN_BIG); | |
417 | } | |
418 | ||
419 | int | |
420 | print_insn_little_nios2 (bfd_vma address, disassemble_info *info) | |
421 | { | |
422 | return print_insn_nios2 (address, info, BFD_ENDIAN_LITTLE); | |
423 | } |