1 /* Morpho Technologies MT specific support for 32-bit ELF
2 Copyright (C) 2001-2023 Free Software Foundation, Inc.
3
4 This file is part of BFD, the Binary File Descriptor library.
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 3 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., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
20
21 #include "sysdep.h"
22 #include "bfd.h"
23 #include "libbfd.h"
24 #include "elf-bfd.h"
25 #include "elf/mt.h"
26
27 /* Prototypes. */
28 static reloc_howto_type * mt_reloc_type_lookup
29 (bfd *, bfd_reloc_code_real_type);
30
31 static bool mt_info_to_howto_rela
32 (bfd *, arelent *, Elf_Internal_Rela *);
33
34 static bfd_reloc_status_type mt_elf_relocate_hi16
35 (bfd *, Elf_Internal_Rela *, bfd_byte *, bfd_vma);
36
37 static bfd_reloc_status_type mt_final_link_relocate
38 (reloc_howto_type *, bfd *, asection *, bfd_byte *,
39 Elf_Internal_Rela *, bfd_vma);
40
41 static int mt_elf_relocate_section
42 (bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
43 Elf_Internal_Rela *, Elf_Internal_Sym *, asection **);
44
45 /* Relocation tables. */
46 static reloc_howto_type mt_elf_howto_table [] =
47 {
48 /* This reloc does nothing. */
49 HOWTO (R_MT_NONE, /* type */
50 0, /* rightshift */
51 0, /* size */
52 0, /* bitsize */
53 false, /* pc_relative */
54 0, /* bitpos */
55 complain_overflow_dont, /* complain_on_overflow */
56 bfd_elf_generic_reloc, /* special_function */
57 "R_MT_NONE", /* name */
58 false, /* partial_inplace */
59 0 , /* src_mask */
60 0, /* dst_mask */
61 false), /* pcrel_offset */
62
63 /* A 16 bit absolute relocation. */
64 HOWTO (R_MT_16, /* type */
65 0, /* rightshift */
66 4, /* size */
67 16, /* bitsize */
68 false, /* pc_relative */
69 0, /* bitpos */
70 complain_overflow_dont, /* complain_on_overflow */
71 bfd_elf_generic_reloc, /* special_function */
72 "R_MT_16", /* name */
73 false, /* partial_inplace */
74 0 , /* src_mask */
75 0xffff, /* dst_mask */
76 false), /* pcrel_offset */
77
78 /* A 32 bit absolute relocation. */
79 HOWTO (R_MT_32, /* type */
80 0, /* rightshift */
81 4, /* size */
82 32, /* bitsize */
83 false, /* pc_relative */
84 0, /* bitpos */
85 complain_overflow_dont, /* complain_on_overflow */
86 bfd_elf_generic_reloc, /* special_function */
87 "R_MT_32", /* name */
88 false, /* partial_inplace */
89 0 , /* src_mask */
90 0xffffffff, /* dst_mask */
91 false), /* pcrel_offset */
92
93 /* A 32 bit pc-relative relocation. */
94 HOWTO (R_MT_32_PCREL, /* type */
95 0, /* rightshift */
96 4, /* size */
97 32, /* bitsize */
98 true, /* pc_relative */
99 0, /* bitpos */
100 complain_overflow_dont, /* complain_on_overflow */
101 bfd_elf_generic_reloc, /* special_function */
102 "R_MT_32_PCREL", /* name */
103 false, /* partial_inplace */
104 0 , /* src_mask */
105 0xffffffff, /* dst_mask */
106 true), /* pcrel_offset */
107
108 /* A 16 bit pc-relative relocation. */
109 HOWTO (R_MT_PC16, /* type */
110 0, /* rightshift */
111 4, /* size */
112 16, /* bitsize */
113 true, /* pc_relative */
114 0, /* bitpos */
115 complain_overflow_signed, /* complain_on_overflow */
116 bfd_elf_generic_reloc, /* special_function */
117 "R_MT_PC16", /* name */
118 false, /* partial_inplace */
119 0, /* src_mask */
120 0xffff, /* dst_mask */
121 true), /* pcrel_offset */
122
123 /* high 16 bits of symbol value. */
124 HOWTO (R_MT_HI16, /* type */
125 0, /* rightshift */
126 4, /* size */
127 16, /* bitsize */
128 false, /* pc_relative */
129 0, /* bitpos */
130 complain_overflow_dont, /* complain_on_overflow */
131 bfd_elf_generic_reloc, /* special_function */
132 "R_MT_HI16", /* name */
133 false, /* partial_inplace */
134 0xffff0000, /* src_mask */
135 0xffff0000, /* dst_mask */
136 false), /* pcrel_offset */
137
138 /* Low 16 bits of symbol value. */
139 HOWTO (R_MT_LO16, /* type */
140 0, /* rightshift */
141 4, /* size */
142 16, /* bitsize */
143 false, /* pc_relative */
144 0, /* bitpos */
145 complain_overflow_dont, /* complain_on_overflow */
146 bfd_elf_generic_reloc, /* special_function */
147 "R_MT_LO16", /* name */
148 false, /* partial_inplace */
149 0xffff, /* src_mask */
150 0xffff, /* dst_mask */
151 false), /* pcrel_offset */
152 };
153
154 /* Map BFD reloc types to MT ELF reloc types. */
155
156 static reloc_howto_type *
157 mt_reloc_type_lookup
158 (bfd * abfd ATTRIBUTE_UNUSED,
159 bfd_reloc_code_real_type code)
160 {
161 /* Note that the mt_elf_howto_table is indxed by the R_
162 constants. Thus, the order that the howto records appear in the
163 table *must* match the order of the relocation types defined in
164 include/elf/mt.h. */
165
166 switch (code)
167 {
168 case BFD_RELOC_NONE:
169 return &mt_elf_howto_table[ (int) R_MT_NONE];
170 case BFD_RELOC_16:
171 return &mt_elf_howto_table[ (int) R_MT_16];
172 case BFD_RELOC_32:
173 return &mt_elf_howto_table[ (int) R_MT_32];
174 case BFD_RELOC_32_PCREL:
175 return &mt_elf_howto_table[ (int) R_MT_32_PCREL];
176 case BFD_RELOC_16_PCREL:
177 return &mt_elf_howto_table[ (int) R_MT_PC16];
178 case BFD_RELOC_HI16:
179 return &mt_elf_howto_table[ (int) R_MT_HI16];
180 case BFD_RELOC_LO16:
181 return &mt_elf_howto_table[ (int) R_MT_LO16];
182
183 default:
184 /* Pacify gcc -Wall. */
185 return NULL;
186 }
187 return NULL;
188 }
189
190 static reloc_howto_type *
191 mt_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
192 const char *r_name)
193 {
194 unsigned int i;
195
196 for (i = 0;
197 i < sizeof (mt_elf_howto_table) / sizeof (mt_elf_howto_table[0]);
198 i++)
199 if (mt_elf_howto_table[i].name != NULL
200 && strcasecmp (mt_elf_howto_table[i].name, r_name) == 0)
201 return &mt_elf_howto_table[i];
202
203 return NULL;
204 }
205
206 bfd_reloc_status_type
207 mt_elf_relocate_hi16
208 (bfd * input_bfd,
209 Elf_Internal_Rela * relhi,
210 bfd_byte * contents,
211 bfd_vma value)
212 {
213 bfd_vma insn;
214
215 insn = bfd_get_32 (input_bfd, contents + relhi->r_offset);
216
217 value += relhi->r_addend;
218 value >>= 16;
219 insn = ((insn & ~0xFFFF) | value);
220
221 bfd_put_32 (input_bfd, insn, contents + relhi->r_offset);
222 return bfd_reloc_ok;
223 }
224
225 /* XXX: The following code is the result of a cut&paste. This unfortunate
226 practice is very widespread in the various target back-end files. */
227
228 /* Set the howto pointer for a MT ELF reloc. */
229
230 static bool
231 mt_info_to_howto_rela (bfd *abfd,
232 arelent *cache_ptr,
233 Elf_Internal_Rela *dst)
234 {
235 unsigned int r_type;
236
237 r_type = ELF32_R_TYPE (dst->r_info);
238 if (r_type >= (unsigned int) R_MT_max)
239 {
240 /* xgettext:c-format */
241 _bfd_error_handler (_("%pB: unsupported relocation type %#x"),
242 abfd, r_type);
243 bfd_set_error (bfd_error_bad_value);
244 return false;
245 }
246 cache_ptr->howto = & mt_elf_howto_table [r_type];
247 return true;
248 }
249
250 /* Perform a single relocation. By default we use the standard BFD
251 routines. */
252
253 static bfd_reloc_status_type
254 mt_final_link_relocate
255 (reloc_howto_type * howto,
256 bfd * input_bfd,
257 asection * input_section,
258 bfd_byte * contents,
259 Elf_Internal_Rela * rel,
260 bfd_vma relocation)
261 {
262 return _bfd_final_link_relocate (howto, input_bfd, input_section,
263 contents, rel->r_offset,
264 relocation, rel->r_addend);
265 }
266
267 /* Relocate a MT ELF section.
268 There is some attempt to make this function usable for many architectures,
269 both USE_REL and USE_RELA ['twould be nice if such a critter existed],
270 if only to serve as a learning tool.
271
272 The RELOCATE_SECTION function is called by the new ELF backend linker
273 to handle the relocations for a section.
274
275 The relocs are always passed as Rela structures; if the section
276 actually uses Rel structures, the r_addend field will always be
277 zero.
278
279 This function is responsible for adjusting the section contents as
280 necessary, and (if using Rela relocs and generating a relocatable
281 output file) adjusting the reloc addend as necessary.
282
283 This function does not have to worry about setting the reloc
284 address or the reloc symbol index.
285
286 LOCAL_SYMS is a pointer to the swapped in local symbols.
287
288 LOCAL_SECTIONS is an array giving the section in the input file
289 corresponding to the st_shndx field of each local symbol.
290
291 The global hash table entry for the global symbols can be found
292 via elf_sym_hashes (input_bfd).
293
294 When generating relocatable output, this function must handle
295 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
296 going to be the section symbol corresponding to the output
297 section, which means that the addend must be adjusted
298 accordingly. */
299
300 static int
301 mt_elf_relocate_section
302 (bfd * output_bfd ATTRIBUTE_UNUSED,
303 struct bfd_link_info * info,
304 bfd * input_bfd,
305 asection * input_section,
306 bfd_byte * contents,
307 Elf_Internal_Rela * relocs,
308 Elf_Internal_Sym * local_syms,
309 asection ** local_sections)
310 {
311 Elf_Internal_Shdr * symtab_hdr;
312 struct elf_link_hash_entry ** sym_hashes;
313 Elf_Internal_Rela * rel;
314 Elf_Internal_Rela * relend;
315
316 symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
317 sym_hashes = elf_sym_hashes (input_bfd);
318 relend = relocs + input_section->reloc_count;
319
320 for (rel = relocs; rel < relend; rel ++)
321 {
322 reloc_howto_type * howto;
323 unsigned long r_symndx;
324 Elf_Internal_Sym * sym;
325 asection * sec;
326 struct elf_link_hash_entry * h;
327 bfd_vma relocation;
328 bfd_reloc_status_type r;
329 const char * name = NULL;
330 int r_type;
331
332 r_type = ELF32_R_TYPE (rel->r_info);
333
334 r_symndx = ELF32_R_SYM (rel->r_info);
335
336 howto = mt_elf_howto_table + ELF32_R_TYPE (rel->r_info);
337 h = NULL;
338 sym = NULL;
339 sec = NULL;
340
341 if (r_symndx < symtab_hdr->sh_info)
342 {
343 sym = local_syms + r_symndx;
344 sec = local_sections [r_symndx];
345 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
346
347 name = bfd_elf_string_from_elf_section
348 (input_bfd, symtab_hdr->sh_link, sym->st_name);
349 name = name == NULL ? bfd_section_name (sec) : name;
350 }
351 else
352 {
353 bool unresolved_reloc;
354 bool warned, ignored;
355
356 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
357 r_symndx, symtab_hdr, sym_hashes,
358 h, sec, relocation,
359 unresolved_reloc, warned, ignored);
360
361 name = h->root.root.string;
362 }
363
364 if (sec != NULL && discarded_section (sec))
365 RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
366 rel, 1, relend, howto, 0, contents);
367
368 if (bfd_link_relocatable (info))
369 continue;
370
371 /* Finally, the sole MT-specific part. */
372 switch (r_type)
373 {
374 case R_MT_HI16:
375 r = mt_elf_relocate_hi16 (input_bfd, rel, contents, relocation);
376 break;
377 default:
378 r = mt_final_link_relocate (howto, input_bfd, input_section,
379 contents, rel, relocation);
380 break;
381 }
382
383
384 if (r != bfd_reloc_ok)
385 {
386 const char * msg = (const char *) NULL;
387
388 switch (r)
389 {
390 case bfd_reloc_overflow:
391 (*info->callbacks->reloc_overflow)
392 (info, (h ? &h->root : NULL), name, howto->name, (bfd_vma) 0,
393 input_bfd, input_section, rel->r_offset);
394 break;
395
396 case bfd_reloc_undefined:
397 (*info->callbacks->undefined_symbol)
398 (info, name, input_bfd, input_section, rel->r_offset, true);
399 break;
400
401 case bfd_reloc_outofrange:
402 msg = _("internal error: out of range error");
403 break;
404
405 case bfd_reloc_dangerous:
406 msg = _("internal error: dangerous relocation");
407 break;
408
409 default:
410 msg = _("internal error: unknown error");
411 break;
412 }
413
414 if (msg)
415 (*info->callbacks->warning) (info, msg, name, input_bfd,
416 input_section, rel->r_offset);
417 }
418 }
419
420 return true;
421 }
422
423 /* Look through the relocs for a section during the first phase.
424 Since we don't do .gots or .plts, we just need to consider the
425 virtual table relocs for gc. */
426
427 static bool
428 mt_elf_check_relocs (bfd *abfd,
429 struct bfd_link_info *info,
430 asection *sec,
431 const Elf_Internal_Rela *relocs)
432 {
433 Elf_Internal_Shdr *symtab_hdr;
434 struct elf_link_hash_entry **sym_hashes;
435 const Elf_Internal_Rela *rel;
436 const Elf_Internal_Rela *rel_end;
437
438 if (bfd_link_relocatable (info))
439 return true;
440
441 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
442 sym_hashes = elf_sym_hashes (abfd);
443
444 rel_end = relocs + sec->reloc_count;
445 for (rel = relocs; rel < rel_end; rel++)
446 {
447 struct elf_link_hash_entry *h;
448 unsigned long r_symndx;
449
450 r_symndx = ELF32_R_SYM (rel->r_info);
451 if (r_symndx < symtab_hdr->sh_info)
452 h = NULL;
453 else
454 {
455 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
456 while (h->root.type == bfd_link_hash_indirect
457 || h->root.type == bfd_link_hash_warning)
458 h = (struct elf_link_hash_entry *) h->root.u.i.link;
459 }
460 }
461
462 return true;
463 }
464
465 /* Return the MACH for an e_flags value. */
466
467 static int
468 elf32_mt_machine (bfd *abfd)
469 {
470 switch (elf_elfheader (abfd)->e_flags & EF_MT_CPU_MASK)
471 {
472 case EF_MT_CPU_MRISC: return bfd_mach_ms1;
473 case EF_MT_CPU_MRISC2: return bfd_mach_mrisc2;
474 case EF_MT_CPU_MS2: return bfd_mach_ms2;
475 }
476
477 return bfd_mach_ms1;
478 }
479
480 static bool
481 mt_elf_object_p (bfd *abfd)
482 {
483 bfd_default_set_arch_mach (abfd, bfd_arch_mt, elf32_mt_machine (abfd));
484
485 return true;
486 }
487
488 /* Function to set the ELF flag bits. */
489
490 static bool
491 mt_elf_set_private_flags (bfd *abfd, flagword flags)
492 {
493 elf_elfheader (abfd)->e_flags = flags;
494 elf_flags_init (abfd) = true;
495 return true;
496 }
497
498 /* Merge backend specific data from an object file to the output
499 object file when linking. */
500
501 static bool
502 mt_elf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
503 {
504 bfd *obfd = info->output_bfd;
505 flagword old_flags, new_flags;
506 bool ok = true;
507
508 /* Check if we have the same endianness. */
509 if (!_bfd_generic_verify_endian_match (ibfd, info))
510 return false;
511
512 /* If they're not both mt, then merging is meaningless, so just
513 don't do it. */
514 if (strcmp (ibfd->arch_info->arch_name, "mt") != 0)
515 return true;
516 if (strcmp (obfd->arch_info->arch_name, "mt") != 0)
517 return true;
518
519 new_flags = elf_elfheader (ibfd)->e_flags;
520 old_flags = elf_elfheader (obfd)->e_flags;
521
522 #ifdef DEBUG
523 _bfd_error_handler ("%pB: old_flags = 0x%.8x, new_flags = 0x%.8x, init = %s",
524 ibfd, old_flags, new_flags, elf_flags_init (obfd) ? "yes" : "no");
525 #endif
526
527 if (!elf_flags_init (obfd))
528 {
529 old_flags = new_flags;
530 elf_flags_init (obfd) = true;
531 }
532 else if ((new_flags & EF_MT_CPU_MASK) != (old_flags & EF_MT_CPU_MASK))
533 {
534 /* CPU has changed. This is invalid, because MRISC, MRISC2 and
535 MS2 are not subsets of each other. */
536 ok = false;
537 }
538
539 if (ok)
540 {
541 obfd->arch_info = ibfd->arch_info;
542 elf_elfheader (obfd)->e_flags = old_flags;
543 }
544
545 return ok;
546 }
547
548 static bool
549 mt_elf_print_private_bfd_data (bfd *abfd, void *ptr)
550 {
551 FILE *file = (FILE *) ptr;
552 flagword flags;
553
554 BFD_ASSERT (abfd != NULL && ptr != NULL);
555
556 /* Print normal ELF private data. */
557 _bfd_elf_print_private_bfd_data (abfd, ptr);
558
559 flags = elf_elfheader (abfd)->e_flags;
560 fprintf (file, _("private flags = 0x%lx:"), (unsigned long) flags);
561
562 switch (flags & EF_MT_CPU_MASK)
563 {
564 default:
565 case EF_MT_CPU_MRISC: fprintf (file, " ms1-16-002"); break;
566 case EF_MT_CPU_MRISC2: fprintf (file, " ms1-16-003"); break;
567 case EF_MT_CPU_MS2: fprintf (file, " ms2"); break;
568 }
569
570 fputc ('\n', file);
571
572 return true;
573 }
574
575
576 #define TARGET_BIG_SYM mt_elf32_vec
577 #define TARGET_BIG_NAME "elf32-mt"
578
579 #define ELF_ARCH bfd_arch_mt
580 #define ELF_MACHINE_CODE EM_MT
581 #define ELF_MAXPAGESIZE 1 /* No pages on the MT. */
582
583 #define elf_info_to_howto_rel NULL
584 #define elf_info_to_howto mt_info_to_howto_rela
585
586 #define elf_backend_relocate_section mt_elf_relocate_section
587
588 #define bfd_elf32_bfd_reloc_type_lookup mt_reloc_type_lookup
589 #define bfd_elf32_bfd_reloc_name_lookup mt_reloc_name_lookup
590
591 #define elf_backend_check_relocs mt_elf_check_relocs
592 #define elf_backend_object_p mt_elf_object_p
593 #define elf_backend_rela_normal 1
594
595 #define elf_backend_can_gc_sections 1
596
597 #define bfd_elf32_bfd_set_private_flags mt_elf_set_private_flags
598 #define bfd_elf32_bfd_merge_private_bfd_data mt_elf_merge_private_bfd_data
599 #define bfd_elf32_bfd_print_private_bfd_data mt_elf_print_private_bfd_data
600
601 #include "elf32-target.h"