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[deliverable/binutils-gdb.git] / bfd / elf32-msp430.c
1 /* MSP430-specific support for 32-bit ELF
2 Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
3 Free Software Foundation, Inc.
4 Contributed by Dmitry Diky <diwil@mail.ru>
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 2 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, MA 02110-1301, USA. */
21
22 #include "bfd.h"
23 #include "sysdep.h"
24 #include "libiberty.h"
25 #include "libbfd.h"
26 #include "elf-bfd.h"
27 #include "elf/msp430.h"
28
29 /* Use RELA instead of REL. */
30 #undef USE_REL
31
32 static reloc_howto_type elf_msp430_howto_table[] =
33 {
34 HOWTO (R_MSP430_NONE, /* type */
35 0, /* rightshift */
36 2, /* size (0 = byte, 1 = short, 2 = long) */
37 32, /* bitsize */
38 FALSE, /* pc_relative */
39 0, /* bitpos */
40 complain_overflow_bitfield,/* complain_on_overflow */
41 bfd_elf_generic_reloc, /* special_function */
42 "R_MSP430_NONE", /* name */
43 FALSE, /* partial_inplace */
44 0, /* src_mask */
45 0, /* dst_mask */
46 FALSE), /* pcrel_offset */
47
48 HOWTO (R_MSP430_32, /* type */
49 0, /* rightshift */
50 2, /* size (0 = byte, 1 = short, 2 = long) */
51 32, /* bitsize */
52 FALSE, /* pc_relative */
53 0, /* bitpos */
54 complain_overflow_bitfield,/* complain_on_overflow */
55 bfd_elf_generic_reloc, /* special_function */
56 "R_MSP430_32", /* name */
57 FALSE, /* partial_inplace */
58 0xffffffff, /* src_mask */
59 0xffffffff, /* dst_mask */
60 FALSE), /* pcrel_offset */
61
62 /* A 13 bit PC relative relocation. */
63 HOWTO (R_MSP430_10_PCREL, /* type */
64 1, /* rightshift */
65 1, /* size (0 = byte, 1 = short, 2 = long) */
66 10, /* bitsize */
67 TRUE, /* pc_relative */
68 0, /* bitpos */
69 complain_overflow_bitfield,/* complain_on_overflow */
70 bfd_elf_generic_reloc, /* special_function */
71 "R_MSP430_13_PCREL", /* name */
72 FALSE, /* partial_inplace */
73 0xfff, /* src_mask */
74 0xfff, /* dst_mask */
75 TRUE), /* pcrel_offset */
76
77 /* A 16 bit absolute relocation. */
78 HOWTO (R_MSP430_16, /* type */
79 0, /* rightshift */
80 1, /* size (0 = byte, 1 = short, 2 = long) */
81 16, /* bitsize */
82 FALSE, /* pc_relative */
83 0, /* bitpos */
84 complain_overflow_dont,/* complain_on_overflow */
85 bfd_elf_generic_reloc, /* special_function */
86 "R_MSP430_16", /* name */
87 FALSE, /* partial_inplace */
88 0, /* src_mask */
89 0xffff, /* dst_mask */
90 FALSE), /* pcrel_offset */
91
92 /* A 16 bit absolute relocation for command address. */
93 HOWTO (R_MSP430_16_PCREL, /* type */
94 1, /* rightshift */
95 1, /* size (0 = byte, 1 = short, 2 = long) */
96 16, /* bitsize */
97 TRUE, /* pc_relative */
98 0, /* bitpos */
99 complain_overflow_dont,/* complain_on_overflow */
100 bfd_elf_generic_reloc, /* special_function */
101 "R_MSP430_16_PCREL", /* name */
102 FALSE, /* partial_inplace */
103 0, /* src_mask */
104 0xffff, /* dst_mask */
105 TRUE), /* pcrel_offset */
106
107 /* A 16 bit absolute relocation, byte operations. */
108 HOWTO (R_MSP430_16_BYTE, /* type */
109 0, /* rightshift */
110 1, /* size (0 = byte, 1 = short, 2 = long) */
111 16, /* bitsize */
112 FALSE, /* pc_relative */
113 0, /* bitpos */
114 complain_overflow_dont,/* complain_on_overflow */
115 bfd_elf_generic_reloc, /* special_function */
116 "R_MSP430_16_BYTE", /* name */
117 FALSE, /* partial_inplace */
118 0xffff, /* src_mask */
119 0xffff, /* dst_mask */
120 FALSE), /* pcrel_offset */
121
122 /* A 16 bit absolute relocation for command address. */
123 HOWTO (R_MSP430_16_PCREL_BYTE,/* type */
124 1, /* rightshift */
125 1, /* size (0 = byte, 1 = short, 2 = long) */
126 16, /* bitsize */
127 TRUE, /* pc_relative */
128 0, /* bitpos */
129 complain_overflow_dont,/* complain_on_overflow */
130 bfd_elf_generic_reloc, /* special_function */
131 "R_MSP430_16_PCREL_BYTE",/* name */
132 FALSE, /* partial_inplace */
133 0xffff, /* src_mask */
134 0xffff, /* dst_mask */
135 TRUE), /* pcrel_offset */
136
137 /* A 13 bit PC relative relocation for complicated polymorphs. */
138 HOWTO (R_MSP430_2X_PCREL, /* type */
139 1, /* rightshift */
140 2, /* size (0 = byte, 1 = short, 2 = long) */
141 10, /* bitsize */
142 TRUE, /* pc_relative */
143 0, /* bitpos */
144 complain_overflow_bitfield,/* complain_on_overflow */
145 bfd_elf_generic_reloc, /* special_function */
146 "R_MSP430_2X_PCREL", /* name */
147 FALSE, /* partial_inplace */
148 0xfff, /* src_mask */
149 0xfff, /* dst_mask */
150 TRUE), /* pcrel_offset */
151
152 /* A 16 bit relaxable relocation for command address. */
153 HOWTO (R_MSP430_RL_PCREL, /* type */
154 1, /* rightshift */
155 1, /* size (0 = byte, 1 = short, 2 = long) */
156 16, /* bitsize */
157 TRUE, /* pc_relative */
158 0, /* bitpos */
159 complain_overflow_dont,/* complain_on_overflow */
160 bfd_elf_generic_reloc, /* special_function */
161 "R_MSP430_RL_PCREL", /* name */
162 FALSE, /* partial_inplace */
163 0, /* src_mask */
164 0xffff, /* dst_mask */
165 TRUE) /* pcrel_offset */
166 };
167
168 /* Map BFD reloc types to MSP430 ELF reloc types. */
169
170 struct msp430_reloc_map
171 {
172 bfd_reloc_code_real_type bfd_reloc_val;
173 unsigned int elf_reloc_val;
174 };
175
176 static const struct msp430_reloc_map msp430_reloc_map[] =
177 {
178 {BFD_RELOC_NONE, R_MSP430_NONE},
179 {BFD_RELOC_32, R_MSP430_32},
180 {BFD_RELOC_MSP430_10_PCREL, R_MSP430_10_PCREL},
181 {BFD_RELOC_16, R_MSP430_16_BYTE},
182 {BFD_RELOC_MSP430_16_PCREL, R_MSP430_16_PCREL},
183 {BFD_RELOC_MSP430_16, R_MSP430_16},
184 {BFD_RELOC_MSP430_16_PCREL_BYTE, R_MSP430_16_PCREL_BYTE},
185 {BFD_RELOC_MSP430_16_BYTE, R_MSP430_16_BYTE},
186 {BFD_RELOC_MSP430_2X_PCREL, R_MSP430_2X_PCREL},
187 {BFD_RELOC_MSP430_RL_PCREL, R_MSP430_RL_PCREL}
188 };
189
190 static reloc_howto_type *
191 bfd_elf32_bfd_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,
192 bfd_reloc_code_real_type code)
193 {
194 unsigned int i;
195
196 for (i = 0; i < ARRAY_SIZE (msp430_reloc_map); i++)
197 if (msp430_reloc_map[i].bfd_reloc_val == code)
198 return &elf_msp430_howto_table[msp430_reloc_map[i].elf_reloc_val];
199
200 return NULL;
201 }
202
203 /* Set the howto pointer for an MSP430 ELF reloc. */
204
205 static void
206 msp430_info_to_howto_rela (bfd * abfd ATTRIBUTE_UNUSED,
207 arelent * cache_ptr,
208 Elf_Internal_Rela * dst)
209 {
210 unsigned int r_type;
211
212 r_type = ELF32_R_TYPE (dst->r_info);
213 BFD_ASSERT (r_type < (unsigned int) R_MSP430_max);
214 cache_ptr->howto = &elf_msp430_howto_table[r_type];
215 }
216
217 /* Look through the relocs for a section during the first phase.
218 Since we don't do .gots or .plts, we just need to consider the
219 virtual table relocs for gc. */
220
221 static bfd_boolean
222 elf32_msp430_check_relocs (bfd * abfd, struct bfd_link_info * info,
223 asection * sec, const Elf_Internal_Rela * relocs)
224 {
225 Elf_Internal_Shdr *symtab_hdr;
226 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
227 const Elf_Internal_Rela *rel;
228 const Elf_Internal_Rela *rel_end;
229
230 if (info->relocatable)
231 return TRUE;
232
233 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
234 sym_hashes = elf_sym_hashes (abfd);
235 sym_hashes_end =
236 sym_hashes + symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
237 if (!elf_bad_symtab (abfd))
238 sym_hashes_end -= symtab_hdr->sh_info;
239
240 rel_end = relocs + sec->reloc_count;
241 for (rel = relocs; rel < rel_end; rel++)
242 {
243 struct elf_link_hash_entry *h;
244 unsigned long r_symndx;
245
246 r_symndx = ELF32_R_SYM (rel->r_info);
247 if (r_symndx < symtab_hdr->sh_info)
248 h = NULL;
249 else
250 {
251 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
252 while (h->root.type == bfd_link_hash_indirect
253 || h->root.type == bfd_link_hash_warning)
254 h = (struct elf_link_hash_entry *) h->root.u.i.link;
255 }
256 }
257
258 return TRUE;
259 }
260
261 /* Perform a single relocation. By default we use the standard BFD
262 routines, but a few relocs, we have to do them ourselves. */
263
264 static bfd_reloc_status_type
265 msp430_final_link_relocate (reloc_howto_type * howto, bfd * input_bfd,
266 asection * input_section, bfd_byte * contents,
267 Elf_Internal_Rela * rel, bfd_vma relocation)
268 {
269 bfd_reloc_status_type r = bfd_reloc_ok;
270 bfd_vma x;
271 bfd_signed_vma srel;
272
273 switch (howto->type)
274 {
275 case R_MSP430_10_PCREL:
276 contents += rel->r_offset;
277 srel = (bfd_signed_vma) relocation;
278 srel += rel->r_addend;
279 srel -= rel->r_offset;
280 srel -= 2; /* Branch instructions add 2 to the PC... */
281 srel -= (input_section->output_section->vma +
282 input_section->output_offset);
283
284 if (srel & 1)
285 return bfd_reloc_outofrange;
286
287 /* MSP430 addresses commands as words. */
288 srel >>= 1;
289
290 /* Check for an overflow. */
291 if (srel < -512 || srel > 511)
292 return bfd_reloc_overflow;
293
294 x = bfd_get_16 (input_bfd, contents);
295 x = (x & 0xfc00) | (srel & 0x3ff);
296 bfd_put_16 (input_bfd, x, contents);
297 break;
298
299 case R_MSP430_2X_PCREL:
300 contents += rel->r_offset;
301 srel = (bfd_signed_vma) relocation;
302 srel += rel->r_addend;
303 srel -= rel->r_offset;
304 srel -= 2; /* Branch instructions add 2 to the PC... */
305 srel -= (input_section->output_section->vma +
306 input_section->output_offset);
307
308 if (srel & 1)
309 return bfd_reloc_outofrange;
310
311 /* MSP430 addresses commands as words. */
312 srel >>= 1;
313
314 /* Check for an overflow. */
315 if (srel < -512 || srel > 511)
316 return bfd_reloc_overflow;
317
318 x = bfd_get_16 (input_bfd, contents);
319 x = (x & 0xfc00) | (srel & 0x3ff);
320 bfd_put_16 (input_bfd, x, contents);
321 /* Handle second jump instruction. */
322 x = bfd_get_16 (input_bfd, contents - 2);
323 srel += 1;
324 x = (x & 0xfc00) | (srel & 0x3ff);
325 bfd_put_16 (input_bfd, x, contents - 2);
326 break;
327
328 case R_MSP430_16_PCREL:
329 case R_MSP430_RL_PCREL:
330 contents += rel->r_offset;
331 srel = (bfd_signed_vma) relocation;
332 srel += rel->r_addend;
333 srel -= rel->r_offset;
334 /* Only branch instructions add 2 to the PC... */
335 srel -= (input_section->output_section->vma +
336 input_section->output_offset);
337
338 if (srel & 1)
339 return bfd_reloc_outofrange;
340
341 bfd_put_16 (input_bfd, srel & 0xffff, contents);
342 break;
343
344 case R_MSP430_16_PCREL_BYTE:
345 contents += rel->r_offset;
346 srel = (bfd_signed_vma) relocation;
347 srel += rel->r_addend;
348 srel -= rel->r_offset;
349 /* Only branch instructions add 2 to the PC... */
350 srel -= (input_section->output_section->vma +
351 input_section->output_offset);
352
353 bfd_put_16 (input_bfd, srel & 0xffff, contents);
354 break;
355
356 case R_MSP430_16_BYTE:
357 contents += rel->r_offset;
358 srel = (bfd_signed_vma) relocation;
359 srel += rel->r_addend;
360 bfd_put_16 (input_bfd, srel & 0xffff, contents);
361 break;
362
363 case R_MSP430_16:
364 contents += rel->r_offset;
365 srel = (bfd_signed_vma) relocation;
366 srel += rel->r_addend;
367
368 if (srel & 1)
369 return bfd_reloc_notsupported;
370
371 bfd_put_16 (input_bfd, srel & 0xffff, contents);
372 break;
373
374 default:
375 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
376 contents, rel->r_offset,
377 relocation, rel->r_addend);
378 }
379
380 return r;
381 }
382
383 /* Relocate an MSP430 ELF section. */
384
385 static bfd_boolean
386 elf32_msp430_relocate_section (bfd * output_bfd ATTRIBUTE_UNUSED,
387 struct bfd_link_info * info,
388 bfd * input_bfd,
389 asection * input_section,
390 bfd_byte * contents,
391 Elf_Internal_Rela * relocs,
392 Elf_Internal_Sym * local_syms,
393 asection ** local_sections)
394 {
395 Elf_Internal_Shdr *symtab_hdr;
396 struct elf_link_hash_entry **sym_hashes;
397 Elf_Internal_Rela *rel;
398 Elf_Internal_Rela *relend;
399
400 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
401 sym_hashes = elf_sym_hashes (input_bfd);
402 relend = relocs + input_section->reloc_count;
403
404 for (rel = relocs; rel < relend; rel++)
405 {
406 reloc_howto_type *howto;
407 unsigned long r_symndx;
408 Elf_Internal_Sym *sym;
409 asection *sec;
410 struct elf_link_hash_entry *h;
411 bfd_vma relocation;
412 bfd_reloc_status_type r;
413 const char *name = NULL;
414 int r_type;
415
416 r_type = ELF32_R_TYPE (rel->r_info);
417 r_symndx = ELF32_R_SYM (rel->r_info);
418 howto = elf_msp430_howto_table + ELF32_R_TYPE (rel->r_info);
419 h = NULL;
420 sym = NULL;
421 sec = NULL;
422
423 if (r_symndx < symtab_hdr->sh_info)
424 {
425 sym = local_syms + r_symndx;
426 sec = local_sections[r_symndx];
427 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
428
429 name = bfd_elf_string_from_elf_section
430 (input_bfd, symtab_hdr->sh_link, sym->st_name);
431 name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
432 }
433 else
434 {
435 bfd_boolean unresolved_reloc, warned;
436
437 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
438 r_symndx, symtab_hdr, sym_hashes,
439 h, sec, relocation,
440 unresolved_reloc, warned);
441 }
442
443 if (sec != NULL && elf_discarded_section (sec))
444 {
445 /* For relocs against symbols from removed linkonce sections,
446 or sections discarded by a linker script, we just want the
447 section contents zeroed. Avoid any special processing. */
448 _bfd_clear_contents (howto, input_bfd, contents + rel->r_offset);
449 rel->r_info = 0;
450 rel->r_addend = 0;
451 continue;
452 }
453
454 if (info->relocatable)
455 continue;
456
457 r = msp430_final_link_relocate (howto, input_bfd, input_section,
458 contents, rel, relocation);
459
460 if (r != bfd_reloc_ok)
461 {
462 const char *msg = (const char *) NULL;
463
464 switch (r)
465 {
466 case bfd_reloc_overflow:
467 r = info->callbacks->reloc_overflow
468 (info, (h ? &h->root : NULL), name, howto->name,
469 (bfd_vma) 0, input_bfd, input_section,
470 rel->r_offset);
471 break;
472
473 case bfd_reloc_undefined:
474 r = info->callbacks->undefined_symbol
475 (info, name, input_bfd, input_section, rel->r_offset, TRUE);
476 break;
477
478 case bfd_reloc_outofrange:
479 msg = _("internal error: out of range error");
480 break;
481
482 case bfd_reloc_notsupported:
483 msg = _("internal error: unsupported relocation error");
484 break;
485
486 case bfd_reloc_dangerous:
487 msg = _("internal error: dangerous relocation");
488 break;
489
490 default:
491 msg = _("internal error: unknown error");
492 break;
493 }
494
495 if (msg)
496 r = info->callbacks->warning
497 (info, msg, name, input_bfd, input_section, rel->r_offset);
498
499 if (!r)
500 return FALSE;
501 }
502
503 }
504
505 return TRUE;
506 }
507
508 /* The final processing done just before writing out a MSP430 ELF object
509 file. This gets the MSP430 architecture right based on the machine
510 number. */
511
512 static void
513 bfd_elf_msp430_final_write_processing (bfd * abfd,
514 bfd_boolean linker ATTRIBUTE_UNUSED)
515 {
516 unsigned long val;
517
518 switch (bfd_get_mach (abfd))
519 {
520 default:
521 case bfd_mach_msp110:
522 val = E_MSP430_MACH_MSP430x11x1;
523 break;
524
525 case bfd_mach_msp11:
526 val = E_MSP430_MACH_MSP430x11;
527 break;
528
529 case bfd_mach_msp12:
530 val = E_MSP430_MACH_MSP430x12;
531 break;
532
533 case bfd_mach_msp13:
534 val = E_MSP430_MACH_MSP430x13;
535 break;
536
537 case bfd_mach_msp14:
538 val = E_MSP430_MACH_MSP430x14;
539 break;
540
541 case bfd_mach_msp15:
542 val = E_MSP430_MACH_MSP430x15;
543 break;
544
545 case bfd_mach_msp16:
546 val = E_MSP430_MACH_MSP430x16;
547 break;
548
549 case bfd_mach_msp31:
550 val = E_MSP430_MACH_MSP430x31;
551 break;
552
553 case bfd_mach_msp32:
554 val = E_MSP430_MACH_MSP430x32;
555 break;
556
557 case bfd_mach_msp33:
558 val = E_MSP430_MACH_MSP430x33;
559 break;
560
561 case bfd_mach_msp41:
562 val = E_MSP430_MACH_MSP430x41;
563 break;
564
565 case bfd_mach_msp42:
566 val = E_MSP430_MACH_MSP430x42;
567 break;
568
569 case bfd_mach_msp43:
570 val = E_MSP430_MACH_MSP430x43;
571 break;
572
573 case bfd_mach_msp44:
574 val = E_MSP430_MACH_MSP430x44;
575 break;
576 }
577
578 elf_elfheader (abfd)->e_machine = EM_MSP430;
579 elf_elfheader (abfd)->e_flags &= ~EF_MSP430_MACH;
580 elf_elfheader (abfd)->e_flags |= val;
581 }
582
583 /* Set the right machine number. */
584
585 static bfd_boolean
586 elf32_msp430_object_p (bfd * abfd)
587 {
588 int e_set = bfd_mach_msp14;
589
590 if (elf_elfheader (abfd)->e_machine == EM_MSP430
591 || elf_elfheader (abfd)->e_machine == EM_MSP430_OLD)
592 {
593 int e_mach = elf_elfheader (abfd)->e_flags & EF_MSP430_MACH;
594
595 switch (e_mach)
596 {
597 default:
598 case E_MSP430_MACH_MSP430x11:
599 e_set = bfd_mach_msp11;
600 break;
601
602 case E_MSP430_MACH_MSP430x11x1:
603 e_set = bfd_mach_msp110;
604 break;
605
606 case E_MSP430_MACH_MSP430x12:
607 e_set = bfd_mach_msp12;
608 break;
609
610 case E_MSP430_MACH_MSP430x13:
611 e_set = bfd_mach_msp13;
612 break;
613
614 case E_MSP430_MACH_MSP430x14:
615 e_set = bfd_mach_msp14;
616 break;
617
618 case E_MSP430_MACH_MSP430x15:
619 e_set = bfd_mach_msp15;
620 break;
621
622 case E_MSP430_MACH_MSP430x16:
623 e_set = bfd_mach_msp16;
624 break;
625
626 case E_MSP430_MACH_MSP430x31:
627 e_set = bfd_mach_msp31;
628 break;
629
630 case E_MSP430_MACH_MSP430x32:
631 e_set = bfd_mach_msp32;
632 break;
633
634 case E_MSP430_MACH_MSP430x33:
635 e_set = bfd_mach_msp33;
636 break;
637
638 case E_MSP430_MACH_MSP430x41:
639 e_set = bfd_mach_msp41;
640 break;
641
642 case E_MSP430_MACH_MSP430x42:
643 e_set = bfd_mach_msp42;
644 break;
645
646 case E_MSP430_MACH_MSP430x43:
647 e_set = bfd_mach_msp43;
648 break;
649
650 case E_MSP430_MACH_MSP430x44:
651 e_set = bfd_mach_msp44;
652 break;
653 }
654 }
655
656 return bfd_default_set_arch_mach (abfd, bfd_arch_msp430, e_set);
657 }
658
659 /* These functions handle relaxing for the msp430.
660 Relaxation required only in two cases:
661 - Bad hand coding like jumps from one section to another or
662 from file to file.
663 - Sibling calls. This will affect onlu 'jump label' polymorph. Without
664 relaxing this enlarges code by 2 bytes. Sibcalls implemented but
665 do not work in gcc's port by the reason I do not know.
666 Anyway, if a relaxation required, user should pass -relax option to the
667 linker.
668
669 There are quite a few relaxing opportunities available on the msp430:
670
671 ================================================================
672
673 1. 3 words -> 1 word
674
675 eq == jeq label jne +4; br lab
676 ne != jne label jeq +4; br lab
677 lt < jl label jge +4; br lab
678 ltu < jlo label lhs +4; br lab
679 ge >= jge label jl +4; br lab
680 geu >= jhs label jlo +4; br lab
681
682 2. 4 words -> 1 word
683
684 ltn < jn jn +2; jmp +4; br lab
685
686 3. 4 words -> 2 words
687
688 gt > jeq +2; jge label jeq +6; jl +4; br label
689 gtu > jeq +2; jhs label jeq +6; jlo +4; br label
690
691 4. 4 words -> 2 words and 2 labels
692
693 leu <= jeq label; jlo label jeq +2; jhs +4; br label
694 le <= jeq label; jl label jeq +2; jge +4; br label
695 =================================================================
696
697 codemap for first cases is (labels masked ):
698 eq: 0x2002,0x4010,0x0000 -> 0x2400
699 ne: 0x2402,0x4010,0x0000 -> 0x2000
700 lt: 0x3402,0x4010,0x0000 -> 0x3800
701 ltu: 0x2c02,0x4010,0x0000 -> 0x2800
702 ge: 0x3802,0x4010,0x0000 -> 0x3400
703 geu: 0x2802,0x4010,0x0000 -> 0x2c00
704
705 second case:
706 ltn: 0x3001,0x3c02,0x4010,0x0000 -> 0x3000
707
708 third case:
709 gt: 0x2403,0x3802,0x4010,0x0000 -> 0x2401,0x3400
710 gtu: 0x2403,0x2802,0x4010,0x0000 -> 0x2401,0x2c00
711
712 fourth case:
713 leu: 0x2401,0x2c02,0x4010,0x0000 -> 0x2400,0x2800
714 le: 0x2401,0x3402,0x4010,0x0000 -> 0x2400,0x3800
715
716 Unspecified case :)
717 jump: 0x4010,0x0000 -> 0x3c00. */
718
719 #define NUMB_RELAX_CODES 12
720 static struct rcodes_s
721 {
722 int f0, f1; /* From code. */
723 int t0, t1; /* To code. */
724 int labels; /* Position of labels: 1 - one label at first
725 word, 2 - one at second word, 3 - two
726 labels at both. */
727 int cdx; /* Words to match. */
728 int bs; /* Shrink bytes. */
729 int off; /* Offset from old label for new code. */
730 int ncl; /* New code length. */
731 } rcode[] =
732 {/* lab,cdx,bs,off,ncl */
733 { 0x0000, 0x0000, 0x3c00, 0x0000, 1, 0, 2, 2, 2}, /* jump */
734 { 0x0000, 0x2002, 0x2400, 0x0000, 1, 1, 4, 4, 2}, /* eq */
735 { 0x0000, 0x2402, 0x2000, 0x0000, 1, 1, 4, 4, 2}, /* ne */
736 { 0x0000, 0x3402, 0x3800, 0x0000, 1, 1, 4, 4, 2}, /* lt */
737 { 0x0000, 0x2c02, 0x2800, 0x0000, 1, 1, 4, 4, 2}, /* ltu */
738 { 0x0000, 0x3802, 0x3400, 0x0000, 1, 1, 4, 4, 2}, /* ge */
739 { 0x0000, 0x2802, 0x2c00, 0x0000, 1, 1, 4, 4, 2}, /* geu */
740 { 0x3001, 0x3c02, 0x3000, 0x0000, 1, 2, 6, 6, 2}, /* ltn */
741 { 0x2403, 0x3802, 0x2401, 0x3400, 2, 2, 4, 6, 4}, /* gt */
742 { 0x2403, 0x2802, 0x2401, 0x2c00, 2, 2, 4, 6, 4}, /* gtu */
743 { 0x2401, 0x2c02, 0x2400, 0x2800, 3, 2, 4, 6, 4}, /* leu , 2 labels */
744 { 0x2401, 0x2c02, 0x2400, 0x2800, 3, 2, 4, 6, 4}, /* le , 2 labels */
745 { 0, 0, 0, 0, 0, 0, 0, 0, 0}
746 };
747
748 /* Return TRUE if a symbol exists at the given address. */
749
750 static bfd_boolean
751 msp430_elf_symbol_address_p (bfd * abfd,
752 asection * sec,
753 Elf_Internal_Sym * isym,
754 bfd_vma addr)
755 {
756 Elf_Internal_Shdr *symtab_hdr;
757 unsigned int sec_shndx;
758 Elf_Internal_Sym *isymend;
759 struct elf_link_hash_entry **sym_hashes;
760 struct elf_link_hash_entry **end_hashes;
761 unsigned int symcount;
762
763 sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
764
765 /* Examine all the local symbols. */
766 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
767 for (isymend = isym + symtab_hdr->sh_info; isym < isymend; isym++)
768 if (isym->st_shndx == sec_shndx && isym->st_value == addr)
769 return TRUE;
770
771 symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
772 - symtab_hdr->sh_info);
773 sym_hashes = elf_sym_hashes (abfd);
774 end_hashes = sym_hashes + symcount;
775 for (; sym_hashes < end_hashes; sym_hashes++)
776 {
777 struct elf_link_hash_entry *sym_hash = *sym_hashes;
778
779 if ((sym_hash->root.type == bfd_link_hash_defined
780 || sym_hash->root.type == bfd_link_hash_defweak)
781 && sym_hash->root.u.def.section == sec
782 && sym_hash->root.u.def.value == addr)
783 return TRUE;
784 }
785
786 return FALSE;
787 }
788
789 /* Adjust all local symbols defined as '.section + 0xXXXX' (.section has sec_shndx)
790 referenced from current and other sections */
791 static bfd_boolean
792 msp430_elf_relax_adjust_locals(bfd * abfd, asection * sec, bfd_vma addr,
793 int count, unsigned int sec_shndx, bfd_vma toaddr)
794 {
795 Elf_Internal_Shdr *symtab_hdr;
796 Elf_Internal_Rela *irel;
797 Elf_Internal_Rela *irelend;
798 Elf_Internal_Sym *isym;
799
800 irel = elf_section_data (sec)->relocs;
801 irelend = irel + sec->reloc_count;
802 symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
803 isym = (Elf_Internal_Sym *) symtab_hdr->contents;
804
805 for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
806 {
807 int sidx = ELF32_R_SYM(irel->r_info);
808 Elf_Internal_Sym *lsym = isym + sidx;
809
810 /* Adjust symbols referenced by .sec+0xXX */
811 if (irel->r_addend > addr && irel->r_addend < toaddr
812 && lsym->st_shndx == sec_shndx)
813 irel->r_addend -= count;
814 }
815
816 return TRUE;
817 }
818
819 /* Delete some bytes from a section while relaxing. */
820
821 static bfd_boolean
822 msp430_elf_relax_delete_bytes (bfd * abfd, asection * sec, bfd_vma addr,
823 int count)
824 {
825 Elf_Internal_Shdr *symtab_hdr;
826 unsigned int sec_shndx;
827 bfd_byte *contents;
828 Elf_Internal_Rela *irel;
829 Elf_Internal_Rela *irelend;
830 Elf_Internal_Rela *irelalign;
831 bfd_vma toaddr;
832 Elf_Internal_Sym *isym;
833 Elf_Internal_Sym *isymend;
834 struct elf_link_hash_entry **sym_hashes;
835 struct elf_link_hash_entry **end_hashes;
836 unsigned int symcount;
837 asection *p;
838
839 sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
840
841 contents = elf_section_data (sec)->this_hdr.contents;
842
843 /* The deletion must stop at the next ALIGN reloc for an aligment
844 power larger than the number of bytes we are deleting. */
845
846 irelalign = NULL;
847 toaddr = sec->size;
848
849 irel = elf_section_data (sec)->relocs;
850 irelend = irel + sec->reloc_count;
851
852 /* Actually delete the bytes. */
853 memmove (contents + addr, contents + addr + count,
854 (size_t) (toaddr - addr - count));
855 sec->size -= count;
856
857 /* Adjust all the relocs. */
858 symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
859 isym = (Elf_Internal_Sym *) symtab_hdr->contents;
860 for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
861 {
862 /* Get the new reloc address. */
863 if ((irel->r_offset > addr && irel->r_offset < toaddr))
864 irel->r_offset -= count;
865 }
866
867 for (p = abfd->sections; p != NULL; p = p->next)
868 msp430_elf_relax_adjust_locals(abfd,p,addr,count,sec_shndx,toaddr);
869
870 /* Adjust the local symbols defined in this section. */
871 symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
872 isym = (Elf_Internal_Sym *) symtab_hdr->contents;
873 for (isymend = isym + symtab_hdr->sh_info; isym < isymend; isym++)
874 if (isym->st_shndx == sec_shndx
875 && isym->st_value > addr && isym->st_value < toaddr)
876 isym->st_value -= count;
877
878 /* Now adjust the global symbols defined in this section. */
879 symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
880 - symtab_hdr->sh_info);
881 sym_hashes = elf_sym_hashes (abfd);
882 end_hashes = sym_hashes + symcount;
883 for (; sym_hashes < end_hashes; sym_hashes++)
884 {
885 struct elf_link_hash_entry *sym_hash = *sym_hashes;
886
887 if ((sym_hash->root.type == bfd_link_hash_defined
888 || sym_hash->root.type == bfd_link_hash_defweak)
889 && sym_hash->root.u.def.section == sec
890 && sym_hash->root.u.def.value > addr
891 && sym_hash->root.u.def.value < toaddr)
892 sym_hash->root.u.def.value -= count;
893 }
894
895 return TRUE;
896 }
897
898
899 static bfd_boolean
900 msp430_elf_relax_section (bfd * abfd, asection * sec,
901 struct bfd_link_info * link_info,
902 bfd_boolean * again)
903 {
904 Elf_Internal_Shdr * symtab_hdr;
905 Elf_Internal_Rela * internal_relocs;
906 Elf_Internal_Rela * irel;
907 Elf_Internal_Rela * irelend;
908 bfd_byte * contents = NULL;
909 Elf_Internal_Sym * isymbuf = NULL;
910
911 /* Assume nothing changes. */
912 *again = FALSE;
913
914 /* We don't have to do anything for a relocatable link, if
915 this section does not have relocs, or if this is not a
916 code section. */
917 if (link_info->relocatable
918 || (sec->flags & SEC_RELOC) == 0
919 || sec->reloc_count == 0 || (sec->flags & SEC_CODE) == 0)
920 return TRUE;
921
922 symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
923
924 /* Get a copy of the native relocations. */
925 internal_relocs =
926 _bfd_elf_link_read_relocs (abfd, sec, NULL, NULL, link_info->keep_memory);
927 if (internal_relocs == NULL)
928 goto error_return;
929
930 /* Walk through them looking for relaxing opportunities. */
931 irelend = internal_relocs + sec->reloc_count;
932 for (irel = internal_relocs; irel < irelend; irel++)
933 {
934 bfd_vma symval;
935
936 /* If this isn't something that can be relaxed, then ignore
937 this reloc. */
938 if (ELF32_R_TYPE (irel->r_info) != (int) R_MSP430_RL_PCREL)
939 continue;
940
941 /* Get the section contents if we haven't done so already. */
942 if (contents == NULL)
943 {
944 /* Get cached copy if it exists. */
945 if (elf_section_data (sec)->this_hdr.contents != NULL)
946 contents = elf_section_data (sec)->this_hdr.contents;
947 else if (! bfd_malloc_and_get_section (abfd, sec, &contents))
948 goto error_return;
949 }
950
951 /* Read this BFD's local symbols if we haven't done so already. */
952 if (isymbuf == NULL && symtab_hdr->sh_info != 0)
953 {
954 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
955 if (isymbuf == NULL)
956 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
957 symtab_hdr->sh_info, 0,
958 NULL, NULL, NULL);
959 if (isymbuf == NULL)
960 goto error_return;
961 }
962
963 /* Get the value of the symbol referred to by the reloc. */
964 if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
965 {
966 /* A local symbol. */
967 Elf_Internal_Sym *isym;
968 asection *sym_sec;
969
970 isym = isymbuf + ELF32_R_SYM (irel->r_info);
971 if (isym->st_shndx == SHN_UNDEF)
972 sym_sec = bfd_und_section_ptr;
973 else if (isym->st_shndx == SHN_ABS)
974 sym_sec = bfd_abs_section_ptr;
975 else if (isym->st_shndx == SHN_COMMON)
976 sym_sec = bfd_com_section_ptr;
977 else
978 sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
979 symval = (isym->st_value
980 + sym_sec->output_section->vma + sym_sec->output_offset);
981 }
982 else
983 {
984 unsigned long indx;
985 struct elf_link_hash_entry *h;
986
987 /* An external symbol. */
988 indx = ELF32_R_SYM (irel->r_info) - symtab_hdr->sh_info;
989 h = elf_sym_hashes (abfd)[indx];
990 BFD_ASSERT (h != NULL);
991
992 if (h->root.type != bfd_link_hash_defined
993 && h->root.type != bfd_link_hash_defweak)
994 /* This appears to be a reference to an undefined
995 symbol. Just ignore it--it will be caught by the
996 regular reloc processing. */
997 continue;
998
999 symval = (h->root.u.def.value
1000 + h->root.u.def.section->output_section->vma
1001 + h->root.u.def.section->output_offset);
1002 }
1003
1004 /* For simplicity of coding, we are going to modify the section
1005 contents, the section relocs, and the BFD symbol table. We
1006 must tell the rest of the code not to free up this
1007 information. It would be possible to instead create a table
1008 of changes which have to be made, as is done in coff-mips.c;
1009 that would be more work, but would require less memory when
1010 the linker is run. */
1011
1012 /* Try to turn a 16bit pc-relative branch into a 10bit pc-relative
1013 branch. */
1014 /* Paranoia? paranoia... */
1015 if (ELF32_R_TYPE (irel->r_info) == (int) R_MSP430_RL_PCREL)
1016 {
1017 bfd_vma value = symval;
1018
1019 /* Deal with pc-relative gunk. */
1020 value -= (sec->output_section->vma + sec->output_offset);
1021 value -= irel->r_offset;
1022 value += irel->r_addend;
1023
1024 /* See if the value will fit in 10 bits, note the high value is
1025 1016 as the target will be two bytes closer if we are
1026 able to relax. */
1027 if ((long) value < 1016 && (long) value > -1016)
1028 {
1029 int code0 = 0, code1 = 0, code2 = 0;
1030 int i;
1031 struct rcodes_s *rx;
1032
1033 /* Get the opcode. */
1034 if (irel->r_offset >= 6)
1035 code0 = bfd_get_16 (abfd, contents + irel->r_offset - 6);
1036
1037 if (irel->r_offset >= 4)
1038 code1 = bfd_get_16 (abfd, contents + irel->r_offset - 4);
1039
1040 code2 = bfd_get_16 (abfd, contents + irel->r_offset - 2);
1041
1042 if (code2 != 0x4010)
1043 continue;
1044
1045 /* Check r4 and r3. */
1046 for (i = NUMB_RELAX_CODES - 1; i >= 0; i--)
1047 {
1048 rx = &rcode[i];
1049 if (rx->cdx == 2 && rx->f0 == code0 && rx->f1 == code1)
1050 break;
1051 else if (rx->cdx == 1 && rx->f1 == code1)
1052 break;
1053 else if (rx->cdx == 0) /* This is an unconditional jump. */
1054 break;
1055 }
1056
1057 /* Check labels:
1058 .Label0: ; we do not care about this label
1059 jeq +6
1060 .Label1: ; make sure there is no label here
1061 jl +4
1062 .Label2: ; make sure there is no label here
1063 br .Label_dst
1064
1065 So, if there is .Label1 or .Label2 we cannot relax this code.
1066 This actually should not happen, cause for relaxable
1067 instructions we use RL_PCREL reloc instead of 16_PCREL.
1068 Will change this in the future. */
1069
1070 if (rx->cdx > 0
1071 && msp430_elf_symbol_address_p (abfd, sec, isymbuf,
1072 irel->r_offset - 2))
1073 continue;
1074 if (rx->cdx > 1
1075 && msp430_elf_symbol_address_p (abfd, sec, isymbuf,
1076 irel->r_offset - 4))
1077 continue;
1078
1079 /* Note that we've changed the relocs, section contents, etc. */
1080 elf_section_data (sec)->relocs = internal_relocs;
1081 elf_section_data (sec)->this_hdr.contents = contents;
1082 symtab_hdr->contents = (unsigned char *) isymbuf;
1083
1084 /* Fix the relocation's type. */
1085 if (rx->labels == 3) /* Handle special cases. */
1086 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1087 R_MSP430_2X_PCREL);
1088 else
1089 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1090 R_MSP430_10_PCREL);
1091
1092 /* Fix the opcode right way. */
1093 bfd_put_16 (abfd, rx->t0, contents + irel->r_offset - rx->off);
1094 if (rx->t1)
1095 bfd_put_16 (abfd, rx->t1,
1096 contents + irel->r_offset - rx->off + 2);
1097
1098 /* Delete bytes. */
1099 if (!msp430_elf_relax_delete_bytes (abfd, sec,
1100 irel->r_offset - rx->off +
1101 rx->ncl, rx->bs))
1102 goto error_return;
1103
1104 /* Handle unconditional jumps. */
1105 if (rx->cdx == 0)
1106 irel->r_offset -= 2;
1107
1108 /* That will change things, so, we should relax again.
1109 Note that this is not required, and it may be slow. */
1110 *again = TRUE;
1111 }
1112 }
1113 }
1114
1115 if (isymbuf != NULL && symtab_hdr->contents != (unsigned char *) isymbuf)
1116 {
1117 if (!link_info->keep_memory)
1118 free (isymbuf);
1119 else
1120 {
1121 /* Cache the symbols for elf_link_input_bfd. */
1122 symtab_hdr->contents = (unsigned char *) isymbuf;
1123 }
1124 }
1125
1126 if (contents != NULL
1127 && elf_section_data (sec)->this_hdr.contents != contents)
1128 {
1129 if (!link_info->keep_memory)
1130 free (contents);
1131 else
1132 {
1133 /* Cache the section contents for elf_link_input_bfd. */
1134 elf_section_data (sec)->this_hdr.contents = contents;
1135 }
1136 }
1137
1138 if (internal_relocs != NULL
1139 && elf_section_data (sec)->relocs != internal_relocs)
1140 free (internal_relocs);
1141
1142 return TRUE;
1143
1144 error_return:
1145 if (isymbuf != NULL && symtab_hdr->contents != (unsigned char *) isymbuf)
1146 free (isymbuf);
1147 if (contents != NULL
1148 && elf_section_data (sec)->this_hdr.contents != contents)
1149 free (contents);
1150 if (internal_relocs != NULL
1151 && elf_section_data (sec)->relocs != internal_relocs)
1152 free (internal_relocs);
1153
1154 return FALSE;
1155 }
1156
1157
1158 #define ELF_ARCH bfd_arch_msp430
1159 #define ELF_MACHINE_CODE EM_MSP430
1160 #define ELF_MACHINE_ALT1 EM_MSP430_OLD
1161 #define ELF_MAXPAGESIZE 1
1162 #define ELF_OSABI ELFOSABI_STANDALONE
1163
1164 #define TARGET_LITTLE_SYM bfd_elf32_msp430_vec
1165 #define TARGET_LITTLE_NAME "elf32-msp430"
1166
1167 #define elf_info_to_howto msp430_info_to_howto_rela
1168 #define elf_info_to_howto_rel NULL
1169 #define elf_backend_relocate_section elf32_msp430_relocate_section
1170 #define elf_backend_check_relocs elf32_msp430_check_relocs
1171 #define elf_backend_can_gc_sections 1
1172 #define elf_backend_final_write_processing bfd_elf_msp430_final_write_processing
1173 #define elf_backend_object_p elf32_msp430_object_p
1174 #define elf_backend_post_process_headers _bfd_elf_set_osabi
1175 #define bfd_elf32_bfd_relax_section msp430_elf_relax_section
1176
1177 #include "elf32-target.h"
GDB Binutils - Deliverables
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