1 /* OpenRISC-specific support for 32-bit ELF.
2 Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007
3 Free Software Foundation, Inc.
4 Contributed by Johan Rydberg, jrydberg@opencores.org
5
6 This file is part of BFD, the Binary File Descriptor library.
7
8 This program 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 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 MA 02110-1301, USA. */
22
23 #include "sysdep.h"
24 #include "bfd.h"
25 #include "libbfd.h"
26 #include "elf-bfd.h"
27 #include "elf/openrisc.h"
28 #include "libiberty.h"
29
30 static reloc_howto_type openrisc_elf_howto_table[] =
31 {
32 /* This reloc does nothing. */
33 HOWTO (R_OPENRISC_NONE, /* type */
34 0, /* rightshift */
35 2, /* size (0 = byte, 1 = short, 2 = long) */
36 32, /* bitsize */
37 FALSE, /* pc_relative */
38 0, /* bitpos */
39 complain_overflow_bitfield, /* complain_on_overflow */
40 bfd_elf_generic_reloc, /* special_function */
41 "R_OPENRISC_NONE", /* name */
42 FALSE, /* partial_inplace */
43 0, /* src_mask */
44 0, /* dst_mask */
45 FALSE), /* pcrel_offset */
46
47 /* A PC relative 26 bit relocation, right shifted by 2. */
48 HOWTO (R_OPENRISC_INSN_REL_26, /* type */
49 2, /* rightshift */
50 2, /* size (0 = byte, 1 = short, 2 = long) */
51 26, /* bitsize */
52 TRUE, /* pc_relative */
53 0, /* bitpos */
54 complain_overflow_signed, /* complain_on_overflow */
55 bfd_elf_generic_reloc, /* special_function */
56 "R_OPENRISC_INSN_REL_26", /* name */
57 FALSE, /* partial_inplace */
58 0x00000000, /* src_mask */
59 0x03ffffff, /* dst_mask */
60 FALSE), /* pcrel_offset */
61
62 /* A absolute 26 bit relocation, right shifted by 2. */
63 HOWTO (R_OPENRISC_INSN_ABS_26, /* type */
64 2, /* rightshift */
65 2, /* size (0 = byte, 1 = short, 2 = long) */
66 26, /* bitsize */
67 FALSE, /* pc_relative */
68 0, /* bitpos */
69 complain_overflow_signed, /* complain_on_overflow */
70 bfd_elf_generic_reloc, /* special_function */
71 "R_OPENRISC_INSN_ABS_26", /* name */
72 FALSE, /* partial_inplace */
73 0x00000000, /* src_mask */
74 0x03ffffff, /* dst_mask */
75 FALSE), /* pcrel_offset */
76
77 HOWTO (R_OPENRISC_LO_16_IN_INSN, /* type */
78 0, /* rightshift */
79 1, /* size (0 = byte, 1 = short, 2 = long) */
80 16, /* bitsize */
81 FALSE, /* pc_relative */
82 0, /* bitpos */
83 complain_overflow_dont, /* complain_on_overflow */
84 bfd_elf_generic_reloc, /* special_function */
85 "R_OPENRISC_LO_16_IN_INSN", /* name */
86 FALSE, /* partial_inplace */
87 0, /* src_mask */
88 0x0000ffff, /* dst_mask */
89 FALSE), /* pcrel_offset */
90
91 HOWTO (R_OPENRISC_HI_16_IN_INSN, /* type */
92 16, /* rightshift */
93 1, /* size (0 = byte, 1 = short, 2 = long) */
94 16, /* bitsize */
95 FALSE, /* pc_relative */
96 0, /* bitpos */
97 complain_overflow_dont, /* complain_on_overflow */
98 bfd_elf_generic_reloc, /* special_function */
99 "R_OPENRISC_HI_16_IN_INSN", /* name */
100 FALSE, /* partial_inplace */
101 0, /* src_mask */
102 0x0000ffff, /* dst_mask */
103 FALSE), /* pcrel_offset */
104
105 /* An 8 bit absolute relocation. */
106 HOWTO (R_OPENRISC_8, /* type */
107 0, /* rightshift */
108 0, /* size (0 = byte, 1 = short, 2 = long) */
109 8, /* bitsize */
110 FALSE, /* pc_relative */
111 0, /* bitpos */
112 complain_overflow_bitfield, /* complain_on_overflow */
113 bfd_elf_generic_reloc, /* special_function */
114 "R_OPENRISC_8", /* name */
115 TRUE, /* partial_inplace */
116 0x0000, /* src_mask */
117 0x00ff, /* dst_mask */
118 FALSE), /* pcrel_offset */
119
120 /* A 16 bit absolute relocation. */
121 HOWTO (R_OPENRISC_16, /* type */
122 0, /* rightshift */
123 1, /* size (0 = byte, 1 = short, 2 = long) */
124 16, /* bitsize */
125 FALSE, /* pc_relative */
126 0, /* bitpos */
127 complain_overflow_bitfield, /* complain_on_overflow */
128 bfd_elf_generic_reloc, /* special_function */
129 "R_OPENRISC_16", /* name */
130 TRUE, /* partial_inplace */
131 0x00000000, /* src_mask */
132 0x0000ffff, /* dst_mask */
133 FALSE), /* pcrel_offset */
134
135 /* A 32 bit absolute relocation. */
136 HOWTO (R_OPENRISC_32, /* type */
137 0, /* rightshift */
138 2, /* size (0 = byte, 1 = short, 2 = long) */
139 32, /* bitsize */
140 FALSE, /* pc_relative */
141 0, /* bitpos */
142 complain_overflow_bitfield, /* complain_on_overflow */
143 bfd_elf_generic_reloc, /* special_function */
144 "R_OPENRISC_32", /* name */
145 TRUE, /* partial_inplace */
146 0x00000000, /* src_mask */
147 0xffffffff, /* dst_mask */
148 FALSE), /* pcrel_offset */
149
150 /* GNU extension to record C++ vtable hierarchy. */
151 HOWTO (R_OPENRISC_GNU_VTINHERIT, /* type */
152 0, /* rightshift */
153 2, /* size (0 = byte, 1 = short, 2 = long) */
154 0, /* bitsize */
155 FALSE, /* pc_relative */
156 0, /* bitpos */
157 complain_overflow_dont, /* complain_on_overflow */
158 NULL, /* special_function */
159 "R_OPENRISC_GNU_VTINHERIT", /* name */
160 FALSE, /* partial_inplace */
161 0, /* src_mask */
162 0, /* dst_mask */
163 FALSE), /* pcrel_offset */
164
165 /* GNU extension to record C++ vtable member usage. */
166 HOWTO (R_OPENRISC_GNU_VTENTRY, /* type */
167 0, /* rightshift */
168 2, /* size (0 = byte, 1 = short, 2 = long) */
169 0, /* bitsize */
170 FALSE, /* pc_relative */
171 0, /* bitpos */
172 complain_overflow_dont, /* complain_on_overflow */
173 _bfd_elf_rel_vtable_reloc_fn, /* special_function */
174 "R_OPENRISC_GNU_VTENTRY", /* name */
175 FALSE, /* partial_inplace */
176 0, /* src_mask */
177 0, /* dst_mask */
178 FALSE), /* pcrel_offset */
179 };
180
181 /* Map BFD reloc types to OpenRISC ELF reloc types. */
182
183 struct openrisc_reloc_map
184 {
185 bfd_reloc_code_real_type bfd_reloc_val;
186 unsigned int openrisc_reloc_val;
187 };
188
189 static const struct openrisc_reloc_map openrisc_reloc_map[] =
190 {
191 { BFD_RELOC_NONE, R_OPENRISC_NONE },
192 { BFD_RELOC_32, R_OPENRISC_32 },
193 { BFD_RELOC_16, R_OPENRISC_16 },
194 { BFD_RELOC_8, R_OPENRISC_8 },
195 { BFD_RELOC_OPENRISC_REL_26, R_OPENRISC_INSN_REL_26 },
196 { BFD_RELOC_OPENRISC_ABS_26, R_OPENRISC_INSN_ABS_26 },
197 { BFD_RELOC_HI16, R_OPENRISC_HI_16_IN_INSN },
198 { BFD_RELOC_LO16, R_OPENRISC_LO_16_IN_INSN },
199 { BFD_RELOC_VTABLE_INHERIT, R_OPENRISC_GNU_VTINHERIT },
200 { BFD_RELOC_VTABLE_ENTRY, R_OPENRISC_GNU_VTENTRY }
201 };
202
203 static reloc_howto_type *
openrisc_reloc_type_lookup(bfd * abfd ATTRIBUTE_UNUSED,bfd_reloc_code_real_type code)204 openrisc_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,
205 bfd_reloc_code_real_type code)
206 {
207 unsigned int i;
208
209 for (i = ARRAY_SIZE (openrisc_reloc_map); --i;)
210 if (openrisc_reloc_map[i].bfd_reloc_val == code)
211 return & openrisc_elf_howto_table[openrisc_reloc_map[i].
212 openrisc_reloc_val];
213
214 return NULL;
215 }
216
217 static reloc_howto_type *
openrisc_reloc_name_lookup(bfd * abfd ATTRIBUTE_UNUSED,const char * r_name)218 openrisc_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
219 const char *r_name)
220 {
221 unsigned int i;
222
223 for (i = 0;
224 i < (sizeof (openrisc_elf_howto_table)
225 / sizeof (openrisc_elf_howto_table[0]));
226 i++)
227 if (openrisc_elf_howto_table[i].name != NULL
228 && strcasecmp (openrisc_elf_howto_table[i].name, r_name) == 0)
229 return &openrisc_elf_howto_table[i];
230
231 return NULL;
232 }
233
234 /* Set the howto pointer for an OpenRISC ELF reloc. */
235
236 static void
openrisc_info_to_howto_rela(bfd * abfd ATTRIBUTE_UNUSED,arelent * cache_ptr,Elf_Internal_Rela * dst)237 openrisc_info_to_howto_rela (bfd * abfd ATTRIBUTE_UNUSED,
238 arelent * cache_ptr,
239 Elf_Internal_Rela * dst)
240 {
241 unsigned int r_type;
242
243 r_type = ELF32_R_TYPE (dst->r_info);
244 BFD_ASSERT (r_type < (unsigned int) R_OPENRISC_max);
245 cache_ptr->howto = & openrisc_elf_howto_table[r_type];
246 }
247
248 /* Perform a single relocation. By default we use the standard BFD
249 routines, but a few relocs, we have to do them ourselves. */
250
251 static bfd_reloc_status_type
openrisc_final_link_relocate(reloc_howto_type * howto,bfd * input_bfd,asection * input_section,bfd_byte * contents,Elf_Internal_Rela * rel,bfd_vma relocation)252 openrisc_final_link_relocate (reloc_howto_type *howto,
253 bfd *input_bfd,
254 asection *input_section,
255 bfd_byte *contents,
256 Elf_Internal_Rela *rel,
257 bfd_vma relocation)
258 {
259 bfd_reloc_status_type r = bfd_reloc_ok;
260
261 switch (howto->type)
262 {
263 case R_OPENRISC_LO_16_IN_INSN:
264 relocation &= 0xffff;
265 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
266 contents, rel->r_offset,
267 relocation, rel->r_addend);
268 break;
269
270 default:
271 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
272 contents, rel->r_offset,
273 relocation, rel->r_addend);
274 }
275
276 return r;
277 }
278
279 /* Relocate an OpenRISC ELF section.
280
281 The RELOCATE_SECTION function is called by the new ELF backend linker
282 to handle the relocations for a section.
283
284 The relocs are always passed as Rela structures; if the section
285 actually uses Rel structures, the r_addend field will always be
286 zero.
287
288 This function is responsible for adjusting the section contents as
289 necessary, and (if using Rela relocs and generating a relocatable
290 output file) adjusting the reloc addend as necessary.
291
292 This function does not have to worry about setting the reloc
293 address or the reloc symbol index.
294
295 LOCAL_SYMS is a pointer to the swapped in local symbols.
296
297 LOCAL_SECTIONS is an array giving the section in the input file
298 corresponding to the st_shndx field of each local symbol.
299
300 The global hash table entry for the global symbols can be found
301 via elf_sym_hashes (input_bfd).
302
303 When generating relocatable output, this function must handle
304 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
305 going to be the section symbol corresponding to the output
306 section, which means that the addend must be adjusted
307 accordingly. */
308
309 static bfd_boolean
openrisc_elf_relocate_section(bfd * output_bfd,struct bfd_link_info * info,bfd * input_bfd,asection * input_section,bfd_byte * contents,Elf_Internal_Rela * relocs,Elf_Internal_Sym * local_syms,asection ** local_sections)310 openrisc_elf_relocate_section (bfd *output_bfd,
311 struct bfd_link_info *info,
312 bfd *input_bfd,
313 asection *input_section,
314 bfd_byte *contents,
315 Elf_Internal_Rela *relocs,
316 Elf_Internal_Sym *local_syms,
317 asection **local_sections)
318 {
319 Elf_Internal_Shdr *symtab_hdr;
320 struct elf_link_hash_entry **sym_hashes;
321 Elf_Internal_Rela *rel;
322 Elf_Internal_Rela *relend;
323
324 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
325 sym_hashes = elf_sym_hashes (input_bfd);
326 relend = relocs + input_section->reloc_count;
327
328 for (rel = relocs; rel < relend; rel++)
329 {
330 reloc_howto_type *howto;
331 unsigned long r_symndx;
332 Elf_Internal_Sym *sym;
333 asection *sec;
334 struct elf_link_hash_entry *h;
335 bfd_vma relocation;
336 bfd_reloc_status_type r;
337 const char *name = NULL;
338 int r_type;
339
340 r_type = ELF32_R_TYPE (rel->r_info);
341 r_symndx = ELF32_R_SYM (rel->r_info);
342
343 if (r_type == R_OPENRISC_GNU_VTINHERIT
344 || r_type == R_OPENRISC_GNU_VTENTRY)
345 continue;
346
347 if ((unsigned int) r_type >
348 (sizeof openrisc_elf_howto_table / sizeof (reloc_howto_type)))
349 abort ();
350
351 howto = openrisc_elf_howto_table + ELF32_R_TYPE (rel->r_info);
352 h = NULL;
353 sym = NULL;
354 sec = NULL;
355
356 if (r_symndx < symtab_hdr->sh_info)
357 {
358 sym = local_syms + r_symndx;
359 sec = local_sections[r_symndx];
360 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
361
362 name = bfd_elf_string_from_elf_section
363 (input_bfd, symtab_hdr->sh_link, sym->st_name);
364 name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
365 }
366 else
367 {
368 bfd_boolean unresolved_reloc, warned;
369
370 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
371 r_symndx, symtab_hdr, sym_hashes,
372 h, sec, relocation,
373 unresolved_reloc, warned);
374 }
375
376 if (sec != NULL && elf_discarded_section (sec))
377 RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
378 rel, relend, howto, contents);
379
380 if (info->relocatable)
381 continue;
382
383 r = openrisc_final_link_relocate (howto, input_bfd, input_section,
384 contents, rel, relocation);
385
386 if (r != bfd_reloc_ok)
387 {
388 const char *msg = NULL;
389
390 switch (r)
391 {
392 case bfd_reloc_overflow:
393 r = info->callbacks->reloc_overflow
394 (info, (h ? &h->root : NULL), name, howto->name,
395 (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
396 break;
397
398 case bfd_reloc_undefined:
399 r = info->callbacks->undefined_symbol
400 (info, name, input_bfd, input_section, rel->r_offset, TRUE);
401 break;
402
403 case bfd_reloc_outofrange:
404 msg = _("internal error: out of range error");
405 break;
406
407 case bfd_reloc_notsupported:
408 msg = _("internal error: unsupported relocation error");
409 break;
410
411 case bfd_reloc_dangerous:
412 msg = _("internal error: dangerous relocation");
413 break;
414
415 default:
416 msg = _("internal error: unknown error");
417 break;
418 }
419
420 if (msg)
421 r = info->callbacks->warning
422 (info, msg, name, input_bfd, input_section, rel->r_offset);
423
424 if (!r)
425 return FALSE;
426 }
427 }
428
429 return TRUE;
430 }
431
432 /* Return the section that should be marked against GC for a given
433 relocation. */
434
435 static asection *
openrisc_elf_gc_mark_hook(asection * sec,struct bfd_link_info * info,Elf_Internal_Rela * rel,struct elf_link_hash_entry * h,Elf_Internal_Sym * sym)436 openrisc_elf_gc_mark_hook (asection *sec,
437 struct bfd_link_info *info,
438 Elf_Internal_Rela *rel,
439 struct elf_link_hash_entry *h,
440 Elf_Internal_Sym *sym)
441 {
442 if (h != NULL)
443 switch (ELF32_R_TYPE (rel->r_info))
444 {
445 case R_OPENRISC_GNU_VTINHERIT:
446 case R_OPENRISC_GNU_VTENTRY:
447 return NULL;
448 }
449
450 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
451 }
452
453 /* Look through the relocs for a section during the first phase.
454 Since we don't do .gots or .plts, we just need to consider the
455 virtual table relocs for gc. */
456
457 static bfd_boolean
openrisc_elf_check_relocs(bfd * abfd,struct bfd_link_info * info,asection * sec,const Elf_Internal_Rela * relocs)458 openrisc_elf_check_relocs (bfd *abfd,
459 struct bfd_link_info *info,
460 asection *sec,
461 const Elf_Internal_Rela *relocs)
462 {
463 Elf_Internal_Shdr *symtab_hdr;
464 struct elf_link_hash_entry **sym_hashes;
465 const Elf_Internal_Rela *rel;
466 const Elf_Internal_Rela *rel_end;
467
468 if (info->relocatable)
469 return TRUE;
470
471 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
472 sym_hashes = elf_sym_hashes (abfd);
473
474 rel_end = relocs + sec->reloc_count;
475 for (rel = relocs; rel < rel_end; rel++)
476 {
477 struct elf_link_hash_entry *h;
478 unsigned long r_symndx;
479
480 r_symndx = ELF32_R_SYM (rel->r_info);
481 if (r_symndx < symtab_hdr->sh_info)
482 h = NULL;
483 else
484 {
485 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
486 while (h->root.type == bfd_link_hash_indirect
487 || h->root.type == bfd_link_hash_warning)
488 h = (struct elf_link_hash_entry *) h->root.u.i.link;
489 }
490
491 switch (ELF32_R_TYPE (rel->r_info))
492 {
493 /* This relocation describes the C++ object vtable hierarchy.
494 Reconstruct it for later use during GC. */
495 case R_OPENRISC_GNU_VTINHERIT:
496 if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
497 return FALSE;
498 break;
499
500 /* This relocation describes which C++ vtable entries are actually
501 used. Record for later use during GC. */
502 case R_OPENRISC_GNU_VTENTRY:
503 BFD_ASSERT (h != NULL);
504 if (h != NULL
505 && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
506 return FALSE;
507 break;
508 }
509 }
510
511 return TRUE;
512 }
513
514 /* Set the right machine number. */
515
516 static bfd_boolean
openrisc_elf_object_p(bfd * abfd)517 openrisc_elf_object_p (bfd *abfd)
518 {
519 bfd_default_set_arch_mach (abfd, bfd_arch_openrisc, 0);
520 return TRUE;
521 }
522
523 /* Store the machine number in the flags field. */
524
525 static void
openrisc_elf_final_write_processing(bfd * abfd,bfd_boolean linker ATTRIBUTE_UNUSED)526 openrisc_elf_final_write_processing (bfd *abfd,
527 bfd_boolean linker ATTRIBUTE_UNUSED)
528 {
529 unsigned long val;
530
531 switch (bfd_get_mach (abfd))
532 {
533 default:
534 val = 0;
535 break;
536 }
537
538 elf_elfheader (abfd)->e_flags &= ~0xf;
539 elf_elfheader (abfd)->e_flags |= val;
540 }
541
542
543 #define ELF_ARCH bfd_arch_openrisc
544 #define ELF_MACHINE_CODE EM_OPENRISC
545 #define ELF_MACHINE_ALT1 EM_OPENRISC_OLD
546 #define ELF_MAXPAGESIZE 0x1000
547
548 #define TARGET_BIG_SYM bfd_elf32_openrisc_vec
549 #define TARGET_BIG_NAME "elf32-openrisc"
550
551 #define elf_info_to_howto_rel NULL
552 #define elf_info_to_howto openrisc_info_to_howto_rela
553 #define elf_backend_relocate_section openrisc_elf_relocate_section
554 #define elf_backend_gc_mark_hook openrisc_elf_gc_mark_hook
555 #define elf_backend_check_relocs openrisc_elf_check_relocs
556
557 #define elf_backend_can_gc_sections 1
558 #define elf_backend_rela_normal 1
559
560 #define bfd_elf32_bfd_reloc_type_lookup openrisc_reloc_type_lookup
561 #define bfd_elf32_bfd_reloc_name_lookup openrisc_reloc_name_lookup
562
563 #define elf_backend_object_p openrisc_elf_object_p
564 #define elf_backend_final_write_processing openrisc_elf_final_write_processing
565
566 #include "elf32-target.h"
567