2010-05-24 Tristan Gingold <gingold@adacore.com>
[binutils.git] / bfd / elf32-msp430.c
blob7a570243d8bdc2a4a5b6539c6c3e8dd6b130af59
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>
6 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
23 #include "sysdep.h"
24 #include "bfd.h"
25 #include "libiberty.h"
26 #include "libbfd.h"
27 #include "elf-bfd.h"
28 #include "elf/msp430.h"
30 /* Use RELA instead of REL. */
31 #undef USE_REL
33 static reloc_howto_type elf_msp430_howto_table[] =
35 HOWTO (R_MSP430_NONE, /* type */
36 0, /* rightshift */
37 2, /* size (0 = byte, 1 = short, 2 = long) */
38 32, /* bitsize */
39 FALSE, /* pc_relative */
40 0, /* bitpos */
41 complain_overflow_bitfield,/* complain_on_overflow */
42 bfd_elf_generic_reloc, /* special_function */
43 "R_MSP430_NONE", /* name */
44 FALSE, /* partial_inplace */
45 0, /* src_mask */
46 0, /* dst_mask */
47 FALSE), /* pcrel_offset */
49 HOWTO (R_MSP430_32, /* type */
50 0, /* rightshift */
51 2, /* size (0 = byte, 1 = short, 2 = long) */
52 32, /* bitsize */
53 FALSE, /* pc_relative */
54 0, /* bitpos */
55 complain_overflow_bitfield,/* complain_on_overflow */
56 bfd_elf_generic_reloc, /* special_function */
57 "R_MSP430_32", /* name */
58 FALSE, /* partial_inplace */
59 0xffffffff, /* src_mask */
60 0xffffffff, /* dst_mask */
61 FALSE), /* pcrel_offset */
63 /* A 13 bit PC relative relocation. */
64 HOWTO (R_MSP430_10_PCREL, /* type */
65 1, /* rightshift */
66 1, /* size (0 = byte, 1 = short, 2 = long) */
67 10, /* bitsize */
68 TRUE, /* pc_relative */
69 0, /* bitpos */
70 complain_overflow_bitfield,/* complain_on_overflow */
71 bfd_elf_generic_reloc, /* special_function */
72 "R_MSP430_13_PCREL", /* name */
73 FALSE, /* partial_inplace */
74 0xfff, /* src_mask */
75 0xfff, /* dst_mask */
76 TRUE), /* pcrel_offset */
78 /* A 16 bit absolute relocation. */
79 HOWTO (R_MSP430_16, /* type */
80 0, /* rightshift */
81 1, /* size (0 = byte, 1 = short, 2 = long) */
82 16, /* bitsize */
83 FALSE, /* pc_relative */
84 0, /* bitpos */
85 complain_overflow_dont,/* complain_on_overflow */
86 bfd_elf_generic_reloc, /* special_function */
87 "R_MSP430_16", /* name */
88 FALSE, /* partial_inplace */
89 0, /* src_mask */
90 0xffff, /* dst_mask */
91 FALSE), /* pcrel_offset */
93 /* A 16 bit absolute relocation for command address. */
94 HOWTO (R_MSP430_16_PCREL, /* type */
95 1, /* rightshift */
96 1, /* size (0 = byte, 1 = short, 2 = long) */
97 16, /* bitsize */
98 TRUE, /* pc_relative */
99 0, /* bitpos */
100 complain_overflow_dont,/* complain_on_overflow */
101 bfd_elf_generic_reloc, /* special_function */
102 "R_MSP430_16_PCREL", /* name */
103 FALSE, /* partial_inplace */
104 0, /* src_mask */
105 0xffff, /* dst_mask */
106 TRUE), /* pcrel_offset */
108 /* A 16 bit absolute relocation, byte operations. */
109 HOWTO (R_MSP430_16_BYTE, /* type */
110 0, /* rightshift */
111 1, /* size (0 = byte, 1 = short, 2 = long) */
112 16, /* bitsize */
113 FALSE, /* pc_relative */
114 0, /* bitpos */
115 complain_overflow_dont,/* complain_on_overflow */
116 bfd_elf_generic_reloc, /* special_function */
117 "R_MSP430_16_BYTE", /* name */
118 FALSE, /* partial_inplace */
119 0xffff, /* src_mask */
120 0xffff, /* dst_mask */
121 FALSE), /* pcrel_offset */
123 /* A 16 bit absolute relocation for command address. */
124 HOWTO (R_MSP430_16_PCREL_BYTE,/* type */
125 1, /* rightshift */
126 1, /* size (0 = byte, 1 = short, 2 = long) */
127 16, /* bitsize */
128 TRUE, /* pc_relative */
129 0, /* bitpos */
130 complain_overflow_dont,/* complain_on_overflow */
131 bfd_elf_generic_reloc, /* special_function */
132 "R_MSP430_16_PCREL_BYTE",/* name */
133 FALSE, /* partial_inplace */
134 0xffff, /* src_mask */
135 0xffff, /* dst_mask */
136 TRUE), /* pcrel_offset */
138 /* A 13 bit PC relative relocation for complicated polymorphs. */
139 HOWTO (R_MSP430_2X_PCREL, /* type */
140 1, /* rightshift */
141 2, /* size (0 = byte, 1 = short, 2 = long) */
142 10, /* bitsize */
143 TRUE, /* pc_relative */
144 0, /* bitpos */
145 complain_overflow_bitfield,/* complain_on_overflow */
146 bfd_elf_generic_reloc, /* special_function */
147 "R_MSP430_2X_PCREL", /* name */
148 FALSE, /* partial_inplace */
149 0xfff, /* src_mask */
150 0xfff, /* dst_mask */
151 TRUE), /* pcrel_offset */
153 /* A 16 bit relaxable relocation for command address. */
154 HOWTO (R_MSP430_RL_PCREL, /* type */
155 1, /* rightshift */
156 1, /* size (0 = byte, 1 = short, 2 = long) */
157 16, /* bitsize */
158 TRUE, /* pc_relative */
159 0, /* bitpos */
160 complain_overflow_dont,/* complain_on_overflow */
161 bfd_elf_generic_reloc, /* special_function */
162 "R_MSP430_RL_PCREL", /* name */
163 FALSE, /* partial_inplace */
164 0, /* src_mask */
165 0xffff, /* dst_mask */
166 TRUE) /* pcrel_offset */
169 /* Map BFD reloc types to MSP430 ELF reloc types. */
171 struct msp430_reloc_map
173 bfd_reloc_code_real_type bfd_reloc_val;
174 unsigned int elf_reloc_val;
177 static const struct msp430_reloc_map msp430_reloc_map[] =
179 {BFD_RELOC_NONE, R_MSP430_NONE},
180 {BFD_RELOC_32, R_MSP430_32},
181 {BFD_RELOC_MSP430_10_PCREL, R_MSP430_10_PCREL},
182 {BFD_RELOC_16, R_MSP430_16_BYTE},
183 {BFD_RELOC_MSP430_16_PCREL, R_MSP430_16_PCREL},
184 {BFD_RELOC_MSP430_16, R_MSP430_16},
185 {BFD_RELOC_MSP430_16_PCREL_BYTE, R_MSP430_16_PCREL_BYTE},
186 {BFD_RELOC_MSP430_16_BYTE, R_MSP430_16_BYTE},
187 {BFD_RELOC_MSP430_2X_PCREL, R_MSP430_2X_PCREL},
188 {BFD_RELOC_MSP430_RL_PCREL, R_MSP430_RL_PCREL}
191 static reloc_howto_type *
192 bfd_elf32_bfd_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,
193 bfd_reloc_code_real_type code)
195 unsigned int i;
197 for (i = 0; i < ARRAY_SIZE (msp430_reloc_map); i++)
198 if (msp430_reloc_map[i].bfd_reloc_val == code)
199 return &elf_msp430_howto_table[msp430_reloc_map[i].elf_reloc_val];
201 return NULL;
204 static reloc_howto_type *
205 bfd_elf32_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
206 const char *r_name)
208 unsigned int i;
210 for (i = 0;
211 i < (sizeof (elf_msp430_howto_table)
212 / sizeof (elf_msp430_howto_table[0]));
213 i++)
214 if (elf_msp430_howto_table[i].name != NULL
215 && strcasecmp (elf_msp430_howto_table[i].name, r_name) == 0)
216 return &elf_msp430_howto_table[i];
218 return NULL;
221 /* Set the howto pointer for an MSP430 ELF reloc. */
223 static void
224 msp430_info_to_howto_rela (bfd * abfd ATTRIBUTE_UNUSED,
225 arelent * cache_ptr,
226 Elf_Internal_Rela * dst)
228 unsigned int r_type;
230 r_type = ELF32_R_TYPE (dst->r_info);
231 BFD_ASSERT (r_type < (unsigned int) R_MSP430_max);
232 cache_ptr->howto = &elf_msp430_howto_table[r_type];
235 /* Look through the relocs for a section during the first phase.
236 Since we don't do .gots or .plts, we just need to consider the
237 virtual table relocs for gc. */
239 static bfd_boolean
240 elf32_msp430_check_relocs (bfd * abfd, struct bfd_link_info * info,
241 asection * sec, const Elf_Internal_Rela * relocs)
243 Elf_Internal_Shdr *symtab_hdr;
244 struct elf_link_hash_entry **sym_hashes;
245 const Elf_Internal_Rela *rel;
246 const Elf_Internal_Rela *rel_end;
248 if (info->relocatable)
249 return TRUE;
251 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
252 sym_hashes = elf_sym_hashes (abfd);
254 rel_end = relocs + sec->reloc_count;
255 for (rel = relocs; rel < rel_end; rel++)
257 struct elf_link_hash_entry *h;
258 unsigned long r_symndx;
260 r_symndx = ELF32_R_SYM (rel->r_info);
261 if (r_symndx < symtab_hdr->sh_info)
262 h = NULL;
263 else
265 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
266 while (h->root.type == bfd_link_hash_indirect
267 || h->root.type == bfd_link_hash_warning)
268 h = (struct elf_link_hash_entry *) h->root.u.i.link;
272 return TRUE;
275 /* Perform a single relocation. By default we use the standard BFD
276 routines, but a few relocs, we have to do them ourselves. */
278 static bfd_reloc_status_type
279 msp430_final_link_relocate (reloc_howto_type * howto, bfd * input_bfd,
280 asection * input_section, bfd_byte * contents,
281 Elf_Internal_Rela * rel, bfd_vma relocation)
283 bfd_reloc_status_type r = bfd_reloc_ok;
284 bfd_vma x;
285 bfd_signed_vma srel;
287 switch (howto->type)
289 case R_MSP430_10_PCREL:
290 contents += rel->r_offset;
291 srel = (bfd_signed_vma) relocation;
292 srel += rel->r_addend;
293 srel -= rel->r_offset;
294 srel -= 2; /* Branch instructions add 2 to the PC... */
295 srel -= (input_section->output_section->vma +
296 input_section->output_offset);
298 if (srel & 1)
299 return bfd_reloc_outofrange;
301 /* MSP430 addresses commands as words. */
302 srel >>= 1;
304 /* Check for an overflow. */
305 if (srel < -512 || srel > 511)
306 return bfd_reloc_overflow;
308 x = bfd_get_16 (input_bfd, contents);
309 x = (x & 0xfc00) | (srel & 0x3ff);
310 bfd_put_16 (input_bfd, x, contents);
311 break;
313 case R_MSP430_2X_PCREL:
314 contents += rel->r_offset;
315 srel = (bfd_signed_vma) relocation;
316 srel += rel->r_addend;
317 srel -= rel->r_offset;
318 srel -= 2; /* Branch instructions add 2 to the PC... */
319 srel -= (input_section->output_section->vma +
320 input_section->output_offset);
322 if (srel & 1)
323 return bfd_reloc_outofrange;
325 /* MSP430 addresses commands as words. */
326 srel >>= 1;
328 /* Check for an overflow. */
329 if (srel < -512 || srel > 511)
330 return bfd_reloc_overflow;
332 x = bfd_get_16 (input_bfd, contents);
333 x = (x & 0xfc00) | (srel & 0x3ff);
334 bfd_put_16 (input_bfd, x, contents);
335 /* Handle second jump instruction. */
336 x = bfd_get_16 (input_bfd, contents - 2);
337 srel += 1;
338 x = (x & 0xfc00) | (srel & 0x3ff);
339 bfd_put_16 (input_bfd, x, contents - 2);
340 break;
342 case R_MSP430_16_PCREL:
343 case R_MSP430_RL_PCREL:
344 contents += rel->r_offset;
345 srel = (bfd_signed_vma) relocation;
346 srel += rel->r_addend;
347 srel -= rel->r_offset;
348 /* Only branch instructions add 2 to the PC... */
349 srel -= (input_section->output_section->vma +
350 input_section->output_offset);
352 if (srel & 1)
353 return bfd_reloc_outofrange;
355 bfd_put_16 (input_bfd, srel & 0xffff, contents);
356 break;
358 case R_MSP430_16_PCREL_BYTE:
359 contents += rel->r_offset;
360 srel = (bfd_signed_vma) relocation;
361 srel += rel->r_addend;
362 srel -= rel->r_offset;
363 /* Only branch instructions add 2 to the PC... */
364 srel -= (input_section->output_section->vma +
365 input_section->output_offset);
367 bfd_put_16 (input_bfd, srel & 0xffff, contents);
368 break;
370 case R_MSP430_16_BYTE:
371 contents += rel->r_offset;
372 srel = (bfd_signed_vma) relocation;
373 srel += rel->r_addend;
374 bfd_put_16 (input_bfd, srel & 0xffff, contents);
375 break;
377 case R_MSP430_16:
378 contents += rel->r_offset;
379 srel = (bfd_signed_vma) relocation;
380 srel += rel->r_addend;
382 if (srel & 1)
383 return bfd_reloc_notsupported;
385 bfd_put_16 (input_bfd, srel & 0xffff, contents);
386 break;
388 default:
389 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
390 contents, rel->r_offset,
391 relocation, rel->r_addend);
394 return r;
397 /* Relocate an MSP430 ELF section. */
399 static bfd_boolean
400 elf32_msp430_relocate_section (bfd * output_bfd ATTRIBUTE_UNUSED,
401 struct bfd_link_info * info,
402 bfd * input_bfd,
403 asection * input_section,
404 bfd_byte * contents,
405 Elf_Internal_Rela * relocs,
406 Elf_Internal_Sym * local_syms,
407 asection ** local_sections)
409 Elf_Internal_Shdr *symtab_hdr;
410 struct elf_link_hash_entry **sym_hashes;
411 Elf_Internal_Rela *rel;
412 Elf_Internal_Rela *relend;
414 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
415 sym_hashes = elf_sym_hashes (input_bfd);
416 relend = relocs + input_section->reloc_count;
418 for (rel = relocs; rel < relend; rel++)
420 reloc_howto_type *howto;
421 unsigned long r_symndx;
422 Elf_Internal_Sym *sym;
423 asection *sec;
424 struct elf_link_hash_entry *h;
425 bfd_vma relocation;
426 bfd_reloc_status_type r;
427 const char *name = NULL;
428 int r_type;
430 r_type = ELF32_R_TYPE (rel->r_info);
431 r_symndx = ELF32_R_SYM (rel->r_info);
432 howto = elf_msp430_howto_table + ELF32_R_TYPE (rel->r_info);
433 h = NULL;
434 sym = NULL;
435 sec = NULL;
437 if (r_symndx < symtab_hdr->sh_info)
439 sym = local_syms + r_symndx;
440 sec = local_sections[r_symndx];
441 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
443 name = bfd_elf_string_from_elf_section
444 (input_bfd, symtab_hdr->sh_link, sym->st_name);
445 name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
447 else
449 bfd_boolean unresolved_reloc, warned;
451 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
452 r_symndx, symtab_hdr, sym_hashes,
453 h, sec, relocation,
454 unresolved_reloc, warned);
457 if (sec != NULL && elf_discarded_section (sec))
459 /* For relocs against symbols from removed linkonce sections,
460 or sections discarded by a linker script, we just want the
461 section contents zeroed. Avoid any special processing. */
462 _bfd_clear_contents (howto, input_bfd, contents + rel->r_offset);
463 rel->r_info = 0;
464 rel->r_addend = 0;
465 continue;
468 if (info->relocatable)
469 continue;
471 r = msp430_final_link_relocate (howto, input_bfd, input_section,
472 contents, rel, relocation);
474 if (r != bfd_reloc_ok)
476 const char *msg = (const char *) NULL;
478 switch (r)
480 case bfd_reloc_overflow:
481 r = info->callbacks->reloc_overflow
482 (info, (h ? &h->root : NULL), name, howto->name,
483 (bfd_vma) 0, input_bfd, input_section,
484 rel->r_offset);
485 break;
487 case bfd_reloc_undefined:
488 r = info->callbacks->undefined_symbol
489 (info, name, input_bfd, input_section, rel->r_offset, TRUE);
490 break;
492 case bfd_reloc_outofrange:
493 msg = _("internal error: out of range error");
494 break;
496 case bfd_reloc_notsupported:
497 msg = _("internal error: unsupported relocation error");
498 break;
500 case bfd_reloc_dangerous:
501 msg = _("internal error: dangerous relocation");
502 break;
504 default:
505 msg = _("internal error: unknown error");
506 break;
509 if (msg)
510 r = info->callbacks->warning
511 (info, msg, name, input_bfd, input_section, rel->r_offset);
513 if (!r)
514 return FALSE;
519 return TRUE;
522 /* The final processing done just before writing out a MSP430 ELF object
523 file. This gets the MSP430 architecture right based on the machine
524 number. */
526 static void
527 bfd_elf_msp430_final_write_processing (bfd * abfd,
528 bfd_boolean linker ATTRIBUTE_UNUSED)
530 unsigned long val;
532 switch (bfd_get_mach (abfd))
534 default:
535 case bfd_mach_msp110:
536 val = E_MSP430_MACH_MSP430x11x1;
537 break;
539 case bfd_mach_msp11:
540 val = E_MSP430_MACH_MSP430x11;
541 break;
543 case bfd_mach_msp12:
544 val = E_MSP430_MACH_MSP430x12;
545 break;
547 case bfd_mach_msp13:
548 val = E_MSP430_MACH_MSP430x13;
549 break;
551 case bfd_mach_msp14:
552 val = E_MSP430_MACH_MSP430x14;
553 break;
555 case bfd_mach_msp15:
556 val = E_MSP430_MACH_MSP430x15;
557 break;
559 case bfd_mach_msp16:
560 val = E_MSP430_MACH_MSP430x16;
561 break;
563 case bfd_mach_msp31:
564 val = E_MSP430_MACH_MSP430x31;
565 break;
567 case bfd_mach_msp32:
568 val = E_MSP430_MACH_MSP430x32;
569 break;
571 case bfd_mach_msp33:
572 val = E_MSP430_MACH_MSP430x33;
573 break;
575 case bfd_mach_msp41:
576 val = E_MSP430_MACH_MSP430x41;
577 break;
579 case bfd_mach_msp42:
580 val = E_MSP430_MACH_MSP430x42;
581 break;
583 case bfd_mach_msp43:
584 val = E_MSP430_MACH_MSP430x43;
585 break;
587 case bfd_mach_msp44:
588 val = E_MSP430_MACH_MSP430x44;
589 break;
592 elf_elfheader (abfd)->e_machine = EM_MSP430;
593 elf_elfheader (abfd)->e_flags &= ~EF_MSP430_MACH;
594 elf_elfheader (abfd)->e_flags |= val;
597 /* Set the right machine number. */
599 static bfd_boolean
600 elf32_msp430_object_p (bfd * abfd)
602 int e_set = bfd_mach_msp14;
604 if (elf_elfheader (abfd)->e_machine == EM_MSP430
605 || elf_elfheader (abfd)->e_machine == EM_MSP430_OLD)
607 int e_mach = elf_elfheader (abfd)->e_flags & EF_MSP430_MACH;
609 switch (e_mach)
611 default:
612 case E_MSP430_MACH_MSP430x11:
613 e_set = bfd_mach_msp11;
614 break;
616 case E_MSP430_MACH_MSP430x11x1:
617 e_set = bfd_mach_msp110;
618 break;
620 case E_MSP430_MACH_MSP430x12:
621 e_set = bfd_mach_msp12;
622 break;
624 case E_MSP430_MACH_MSP430x13:
625 e_set = bfd_mach_msp13;
626 break;
628 case E_MSP430_MACH_MSP430x14:
629 e_set = bfd_mach_msp14;
630 break;
632 case E_MSP430_MACH_MSP430x15:
633 e_set = bfd_mach_msp15;
634 break;
636 case E_MSP430_MACH_MSP430x16:
637 e_set = bfd_mach_msp16;
638 break;
640 case E_MSP430_MACH_MSP430x31:
641 e_set = bfd_mach_msp31;
642 break;
644 case E_MSP430_MACH_MSP430x32:
645 e_set = bfd_mach_msp32;
646 break;
648 case E_MSP430_MACH_MSP430x33:
649 e_set = bfd_mach_msp33;
650 break;
652 case E_MSP430_MACH_MSP430x41:
653 e_set = bfd_mach_msp41;
654 break;
656 case E_MSP430_MACH_MSP430x42:
657 e_set = bfd_mach_msp42;
658 break;
660 case E_MSP430_MACH_MSP430x43:
661 e_set = bfd_mach_msp43;
662 break;
664 case E_MSP430_MACH_MSP430x44:
665 e_set = bfd_mach_msp44;
666 break;
670 return bfd_default_set_arch_mach (abfd, bfd_arch_msp430, e_set);
673 /* These functions handle relaxing for the msp430.
674 Relaxation required only in two cases:
675 - Bad hand coding like jumps from one section to another or
676 from file to file.
677 - Sibling calls. This will affect onlu 'jump label' polymorph. Without
678 relaxing this enlarges code by 2 bytes. Sibcalls implemented but
679 do not work in gcc's port by the reason I do not know.
680 Anyway, if a relaxation required, user should pass -relax option to the
681 linker.
683 There are quite a few relaxing opportunities available on the msp430:
685 ================================================================
687 1. 3 words -> 1 word
689 eq == jeq label jne +4; br lab
690 ne != jne label jeq +4; br lab
691 lt < jl label jge +4; br lab
692 ltu < jlo label lhs +4; br lab
693 ge >= jge label jl +4; br lab
694 geu >= jhs label jlo +4; br lab
696 2. 4 words -> 1 word
698 ltn < jn jn +2; jmp +4; br lab
700 3. 4 words -> 2 words
702 gt > jeq +2; jge label jeq +6; jl +4; br label
703 gtu > jeq +2; jhs label jeq +6; jlo +4; br label
705 4. 4 words -> 2 words and 2 labels
707 leu <= jeq label; jlo label jeq +2; jhs +4; br label
708 le <= jeq label; jl label jeq +2; jge +4; br label
709 =================================================================
711 codemap for first cases is (labels masked ):
712 eq: 0x2002,0x4010,0x0000 -> 0x2400
713 ne: 0x2402,0x4010,0x0000 -> 0x2000
714 lt: 0x3402,0x4010,0x0000 -> 0x3800
715 ltu: 0x2c02,0x4010,0x0000 -> 0x2800
716 ge: 0x3802,0x4010,0x0000 -> 0x3400
717 geu: 0x2802,0x4010,0x0000 -> 0x2c00
719 second case:
720 ltn: 0x3001,0x3c02,0x4010,0x0000 -> 0x3000
722 third case:
723 gt: 0x2403,0x3802,0x4010,0x0000 -> 0x2401,0x3400
724 gtu: 0x2403,0x2802,0x4010,0x0000 -> 0x2401,0x2c00
726 fourth case:
727 leu: 0x2401,0x2c02,0x4010,0x0000 -> 0x2400,0x2800
728 le: 0x2401,0x3402,0x4010,0x0000 -> 0x2400,0x3800
730 Unspecified case :)
731 jump: 0x4010,0x0000 -> 0x3c00. */
733 #define NUMB_RELAX_CODES 12
734 static struct rcodes_s
736 int f0, f1; /* From code. */
737 int t0, t1; /* To code. */
738 int labels; /* Position of labels: 1 - one label at first
739 word, 2 - one at second word, 3 - two
740 labels at both. */
741 int cdx; /* Words to match. */
742 int bs; /* Shrink bytes. */
743 int off; /* Offset from old label for new code. */
744 int ncl; /* New code length. */
745 } rcode[] =
746 {/* lab,cdx,bs,off,ncl */
747 { 0x0000, 0x0000, 0x3c00, 0x0000, 1, 0, 2, 2, 2}, /* jump */
748 { 0x0000, 0x2002, 0x2400, 0x0000, 1, 1, 4, 4, 2}, /* eq */
749 { 0x0000, 0x2402, 0x2000, 0x0000, 1, 1, 4, 4, 2}, /* ne */
750 { 0x0000, 0x3402, 0x3800, 0x0000, 1, 1, 4, 4, 2}, /* lt */
751 { 0x0000, 0x2c02, 0x2800, 0x0000, 1, 1, 4, 4, 2}, /* ltu */
752 { 0x0000, 0x3802, 0x3400, 0x0000, 1, 1, 4, 4, 2}, /* ge */
753 { 0x0000, 0x2802, 0x2c00, 0x0000, 1, 1, 4, 4, 2}, /* geu */
754 { 0x3001, 0x3c02, 0x3000, 0x0000, 1, 2, 6, 6, 2}, /* ltn */
755 { 0x2403, 0x3802, 0x2401, 0x3400, 2, 2, 4, 6, 4}, /* gt */
756 { 0x2403, 0x2802, 0x2401, 0x2c00, 2, 2, 4, 6, 4}, /* gtu */
757 { 0x2401, 0x2c02, 0x2400, 0x2800, 3, 2, 4, 6, 4}, /* leu , 2 labels */
758 { 0x2401, 0x2c02, 0x2400, 0x2800, 3, 2, 4, 6, 4}, /* le , 2 labels */
759 { 0, 0, 0, 0, 0, 0, 0, 0, 0}
762 /* Return TRUE if a symbol exists at the given address. */
764 static bfd_boolean
765 msp430_elf_symbol_address_p (bfd * abfd,
766 asection * sec,
767 Elf_Internal_Sym * isym,
768 bfd_vma addr)
770 Elf_Internal_Shdr *symtab_hdr;
771 unsigned int sec_shndx;
772 Elf_Internal_Sym *isymend;
773 struct elf_link_hash_entry **sym_hashes;
774 struct elf_link_hash_entry **end_hashes;
775 unsigned int symcount;
777 sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
779 /* Examine all the local symbols. */
780 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
781 for (isymend = isym + symtab_hdr->sh_info; isym < isymend; isym++)
782 if (isym->st_shndx == sec_shndx && isym->st_value == addr)
783 return TRUE;
785 symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
786 - symtab_hdr->sh_info);
787 sym_hashes = elf_sym_hashes (abfd);
788 end_hashes = sym_hashes + symcount;
789 for (; sym_hashes < end_hashes; sym_hashes++)
791 struct elf_link_hash_entry *sym_hash = *sym_hashes;
793 if ((sym_hash->root.type == bfd_link_hash_defined
794 || sym_hash->root.type == bfd_link_hash_defweak)
795 && sym_hash->root.u.def.section == sec
796 && sym_hash->root.u.def.value == addr)
797 return TRUE;
800 return FALSE;
803 /* Adjust all local symbols defined as '.section + 0xXXXX' (.section has sec_shndx)
804 referenced from current and other sections */
805 static bfd_boolean
806 msp430_elf_relax_adjust_locals(bfd * abfd, asection * sec, bfd_vma addr,
807 int count, unsigned int sec_shndx, bfd_vma toaddr)
809 Elf_Internal_Shdr *symtab_hdr;
810 Elf_Internal_Rela *irel;
811 Elf_Internal_Rela *irelend;
812 Elf_Internal_Sym *isym;
814 irel = elf_section_data (sec)->relocs;
815 irelend = irel + sec->reloc_count;
816 symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
817 isym = (Elf_Internal_Sym *) symtab_hdr->contents;
819 for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
821 int sidx = ELF32_R_SYM(irel->r_info);
822 Elf_Internal_Sym *lsym = isym + sidx;
824 /* Adjust symbols referenced by .sec+0xXX */
825 if (irel->r_addend > addr && irel->r_addend < toaddr
826 && lsym->st_shndx == sec_shndx)
827 irel->r_addend -= count;
830 return TRUE;
833 /* Delete some bytes from a section while relaxing. */
835 static bfd_boolean
836 msp430_elf_relax_delete_bytes (bfd * abfd, asection * sec, bfd_vma addr,
837 int count)
839 Elf_Internal_Shdr *symtab_hdr;
840 unsigned int sec_shndx;
841 bfd_byte *contents;
842 Elf_Internal_Rela *irel;
843 Elf_Internal_Rela *irelend;
844 Elf_Internal_Rela *irelalign;
845 bfd_vma toaddr;
846 Elf_Internal_Sym *isym;
847 Elf_Internal_Sym *isymend;
848 struct elf_link_hash_entry **sym_hashes;
849 struct elf_link_hash_entry **end_hashes;
850 unsigned int symcount;
851 asection *p;
853 sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
855 contents = elf_section_data (sec)->this_hdr.contents;
857 /* The deletion must stop at the next ALIGN reloc for an aligment
858 power larger than the number of bytes we are deleting. */
860 irelalign = NULL;
861 toaddr = sec->size;
863 irel = elf_section_data (sec)->relocs;
864 irelend = irel + sec->reloc_count;
866 /* Actually delete the bytes. */
867 memmove (contents + addr, contents + addr + count,
868 (size_t) (toaddr - addr - count));
869 sec->size -= count;
871 /* Adjust all the relocs. */
872 symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
873 isym = (Elf_Internal_Sym *) symtab_hdr->contents;
874 for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
876 /* Get the new reloc address. */
877 if ((irel->r_offset > addr && irel->r_offset < toaddr))
878 irel->r_offset -= count;
881 for (p = abfd->sections; p != NULL; p = p->next)
882 msp430_elf_relax_adjust_locals(abfd,p,addr,count,sec_shndx,toaddr);
884 /* Adjust the local symbols defined in this section. */
885 symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
886 isym = (Elf_Internal_Sym *) symtab_hdr->contents;
887 for (isymend = isym + symtab_hdr->sh_info; isym < isymend; isym++)
888 if (isym->st_shndx == sec_shndx
889 && isym->st_value > addr && isym->st_value < toaddr)
890 isym->st_value -= count;
892 /* Now adjust the global symbols defined in this section. */
893 symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
894 - symtab_hdr->sh_info);
895 sym_hashes = elf_sym_hashes (abfd);
896 end_hashes = sym_hashes + symcount;
897 for (; sym_hashes < end_hashes; sym_hashes++)
899 struct elf_link_hash_entry *sym_hash = *sym_hashes;
901 if ((sym_hash->root.type == bfd_link_hash_defined
902 || sym_hash->root.type == bfd_link_hash_defweak)
903 && sym_hash->root.u.def.section == sec
904 && sym_hash->root.u.def.value > addr
905 && sym_hash->root.u.def.value < toaddr)
906 sym_hash->root.u.def.value -= count;
909 return TRUE;
913 static bfd_boolean
914 msp430_elf_relax_section (bfd * abfd, asection * sec,
915 struct bfd_link_info * link_info,
916 bfd_boolean * again)
918 Elf_Internal_Shdr * symtab_hdr;
919 Elf_Internal_Rela * internal_relocs;
920 Elf_Internal_Rela * irel;
921 Elf_Internal_Rela * irelend;
922 bfd_byte * contents = NULL;
923 Elf_Internal_Sym * isymbuf = NULL;
925 /* Assume nothing changes. */
926 *again = FALSE;
928 /* We don't have to do anything for a relocatable link, if
929 this section does not have relocs, or if this is not a
930 code section. */
931 if (link_info->relocatable
932 || (sec->flags & SEC_RELOC) == 0
933 || sec->reloc_count == 0 || (sec->flags & SEC_CODE) == 0)
934 return TRUE;
936 symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
938 /* Get a copy of the native relocations. */
939 internal_relocs =
940 _bfd_elf_link_read_relocs (abfd, sec, NULL, NULL, link_info->keep_memory);
941 if (internal_relocs == NULL)
942 goto error_return;
944 /* Walk through them looking for relaxing opportunities. */
945 irelend = internal_relocs + sec->reloc_count;
946 for (irel = internal_relocs; irel < irelend; irel++)
948 bfd_vma symval;
950 /* If this isn't something that can be relaxed, then ignore
951 this reloc. */
952 if (ELF32_R_TYPE (irel->r_info) != (int) R_MSP430_RL_PCREL)
953 continue;
955 /* Get the section contents if we haven't done so already. */
956 if (contents == NULL)
958 /* Get cached copy if it exists. */
959 if (elf_section_data (sec)->this_hdr.contents != NULL)
960 contents = elf_section_data (sec)->this_hdr.contents;
961 else if (! bfd_malloc_and_get_section (abfd, sec, &contents))
962 goto error_return;
965 /* Read this BFD's local symbols if we haven't done so already. */
966 if (isymbuf == NULL && symtab_hdr->sh_info != 0)
968 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
969 if (isymbuf == NULL)
970 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
971 symtab_hdr->sh_info, 0,
972 NULL, NULL, NULL);
973 if (isymbuf == NULL)
974 goto error_return;
977 /* Get the value of the symbol referred to by the reloc. */
978 if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
980 /* A local symbol. */
981 Elf_Internal_Sym *isym;
982 asection *sym_sec;
984 isym = isymbuf + ELF32_R_SYM (irel->r_info);
985 if (isym->st_shndx == SHN_UNDEF)
986 sym_sec = bfd_und_section_ptr;
987 else if (isym->st_shndx == SHN_ABS)
988 sym_sec = bfd_abs_section_ptr;
989 else if (isym->st_shndx == SHN_COMMON)
990 sym_sec = bfd_com_section_ptr;
991 else
992 sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
993 symval = (isym->st_value
994 + sym_sec->output_section->vma + sym_sec->output_offset);
996 else
998 unsigned long indx;
999 struct elf_link_hash_entry *h;
1001 /* An external symbol. */
1002 indx = ELF32_R_SYM (irel->r_info) - symtab_hdr->sh_info;
1003 h = elf_sym_hashes (abfd)[indx];
1004 BFD_ASSERT (h != NULL);
1006 if (h->root.type != bfd_link_hash_defined
1007 && h->root.type != bfd_link_hash_defweak)
1008 /* This appears to be a reference to an undefined
1009 symbol. Just ignore it--it will be caught by the
1010 regular reloc processing. */
1011 continue;
1013 symval = (h->root.u.def.value
1014 + h->root.u.def.section->output_section->vma
1015 + h->root.u.def.section->output_offset);
1018 /* For simplicity of coding, we are going to modify the section
1019 contents, the section relocs, and the BFD symbol table. We
1020 must tell the rest of the code not to free up this
1021 information. It would be possible to instead create a table
1022 of changes which have to be made, as is done in coff-mips.c;
1023 that would be more work, but would require less memory when
1024 the linker is run. */
1026 /* Try to turn a 16bit pc-relative branch into a 10bit pc-relative
1027 branch. */
1028 /* Paranoia? paranoia... */
1029 if (ELF32_R_TYPE (irel->r_info) == (int) R_MSP430_RL_PCREL)
1031 bfd_vma value = symval;
1033 /* Deal with pc-relative gunk. */
1034 value -= (sec->output_section->vma + sec->output_offset);
1035 value -= irel->r_offset;
1036 value += irel->r_addend;
1038 /* See if the value will fit in 10 bits, note the high value is
1039 1016 as the target will be two bytes closer if we are
1040 able to relax. */
1041 if ((long) value < 1016 && (long) value > -1016)
1043 int code0 = 0, code1 = 0, code2 = 0;
1044 int i;
1045 struct rcodes_s *rx;
1047 /* Get the opcode. */
1048 if (irel->r_offset >= 6)
1049 code0 = bfd_get_16 (abfd, contents + irel->r_offset - 6);
1051 if (irel->r_offset >= 4)
1052 code1 = bfd_get_16 (abfd, contents + irel->r_offset - 4);
1054 code2 = bfd_get_16 (abfd, contents + irel->r_offset - 2);
1056 if (code2 != 0x4010)
1057 continue;
1059 /* Check r4 and r3. */
1060 for (i = NUMB_RELAX_CODES - 1; i >= 0; i--)
1062 rx = &rcode[i];
1063 if (rx->cdx == 2 && rx->f0 == code0 && rx->f1 == code1)
1064 break;
1065 else if (rx->cdx == 1 && rx->f1 == code1)
1066 break;
1067 else if (rx->cdx == 0) /* This is an unconditional jump. */
1068 break;
1071 /* Check labels:
1072 .Label0: ; we do not care about this label
1073 jeq +6
1074 .Label1: ; make sure there is no label here
1075 jl +4
1076 .Label2: ; make sure there is no label here
1077 br .Label_dst
1079 So, if there is .Label1 or .Label2 we cannot relax this code.
1080 This actually should not happen, cause for relaxable
1081 instructions we use RL_PCREL reloc instead of 16_PCREL.
1082 Will change this in the future. */
1084 if (rx->cdx > 0
1085 && msp430_elf_symbol_address_p (abfd, sec, isymbuf,
1086 irel->r_offset - 2))
1087 continue;
1088 if (rx->cdx > 1
1089 && msp430_elf_symbol_address_p (abfd, sec, isymbuf,
1090 irel->r_offset - 4))
1091 continue;
1093 /* Note that we've changed the relocs, section contents, etc. */
1094 elf_section_data (sec)->relocs = internal_relocs;
1095 elf_section_data (sec)->this_hdr.contents = contents;
1096 symtab_hdr->contents = (unsigned char *) isymbuf;
1098 /* Fix the relocation's type. */
1099 if (rx->labels == 3) /* Handle special cases. */
1100 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1101 R_MSP430_2X_PCREL);
1102 else
1103 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1104 R_MSP430_10_PCREL);
1106 /* Fix the opcode right way. */
1107 bfd_put_16 (abfd, rx->t0, contents + irel->r_offset - rx->off);
1108 if (rx->t1)
1109 bfd_put_16 (abfd, rx->t1,
1110 contents + irel->r_offset - rx->off + 2);
1112 /* Delete bytes. */
1113 if (!msp430_elf_relax_delete_bytes (abfd, sec,
1114 irel->r_offset - rx->off +
1115 rx->ncl, rx->bs))
1116 goto error_return;
1118 /* Handle unconditional jumps. */
1119 if (rx->cdx == 0)
1120 irel->r_offset -= 2;
1122 /* That will change things, so, we should relax again.
1123 Note that this is not required, and it may be slow. */
1124 *again = TRUE;
1129 if (isymbuf != NULL && symtab_hdr->contents != (unsigned char *) isymbuf)
1131 if (!link_info->keep_memory)
1132 free (isymbuf);
1133 else
1135 /* Cache the symbols for elf_link_input_bfd. */
1136 symtab_hdr->contents = (unsigned char *) isymbuf;
1140 if (contents != NULL
1141 && elf_section_data (sec)->this_hdr.contents != contents)
1143 if (!link_info->keep_memory)
1144 free (contents);
1145 else
1147 /* Cache the section contents for elf_link_input_bfd. */
1148 elf_section_data (sec)->this_hdr.contents = contents;
1152 if (internal_relocs != NULL
1153 && elf_section_data (sec)->relocs != internal_relocs)
1154 free (internal_relocs);
1156 return TRUE;
1158 error_return:
1159 if (isymbuf != NULL && symtab_hdr->contents != (unsigned char *) isymbuf)
1160 free (isymbuf);
1161 if (contents != NULL
1162 && elf_section_data (sec)->this_hdr.contents != contents)
1163 free (contents);
1164 if (internal_relocs != NULL
1165 && elf_section_data (sec)->relocs != internal_relocs)
1166 free (internal_relocs);
1168 return FALSE;
1172 #define ELF_ARCH bfd_arch_msp430
1173 #define ELF_MACHINE_CODE EM_MSP430
1174 #define ELF_MACHINE_ALT1 EM_MSP430_OLD
1175 #define ELF_MAXPAGESIZE 1
1176 #define ELF_OSABI ELFOSABI_STANDALONE
1178 #define TARGET_LITTLE_SYM bfd_elf32_msp430_vec
1179 #define TARGET_LITTLE_NAME "elf32-msp430"
1181 #define elf_info_to_howto msp430_info_to_howto_rela
1182 #define elf_info_to_howto_rel NULL
1183 #define elf_backend_relocate_section elf32_msp430_relocate_section
1184 #define elf_backend_check_relocs elf32_msp430_check_relocs
1185 #define elf_backend_can_gc_sections 1
1186 #define elf_backend_final_write_processing bfd_elf_msp430_final_write_processing
1187 #define elf_backend_object_p elf32_msp430_object_p
1188 #define elf_backend_post_process_headers _bfd_elf_set_osabi
1189 #define bfd_elf32_bfd_relax_section msp430_elf_relax_section
1191 #include "elf32-target.h"