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Add linker relaxation support for the AVR
[deliverable/binutils-gdb.git] / bfd / elf32-avr.c
1 /* AVR-specific support for 32-bit ELF
2 Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2006
3 Free Software Foundation, Inc.
4 Contributed by Denis Chertykov <denisc@overta.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,
21 Boston, MA 02110-1301, USA. */
22
23 #include "bfd.h"
24 #include "sysdep.h"
25 #include "libbfd.h"
26 #include "elf-bfd.h"
27 #include "elf/avr.h"
28
29 static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
30 PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
31 static void avr_info_to_howto_rela
32 PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));
33 static asection *elf32_avr_gc_mark_hook
34 PARAMS ((asection *, struct bfd_link_info *, Elf_Internal_Rela *,
35 struct elf_link_hash_entry *, Elf_Internal_Sym *));
36 static bfd_boolean elf32_avr_gc_sweep_hook
37 PARAMS ((bfd *, struct bfd_link_info *, asection *,
38 const Elf_Internal_Rela *));
39 static bfd_boolean elf32_avr_check_relocs
40 PARAMS ((bfd *, struct bfd_link_info *, asection *,
41 const Elf_Internal_Rela *));
42 static bfd_reloc_status_type avr_final_link_relocate
43 PARAMS ((reloc_howto_type *, bfd *, asection *, bfd_byte *,
44 Elf_Internal_Rela *, bfd_vma));
45 static bfd_boolean elf32_avr_relocate_section
46 PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
47 Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));
48 static void bfd_elf_avr_final_write_processing PARAMS ((bfd *, bfd_boolean));
49 static bfd_boolean elf32_avr_object_p PARAMS ((bfd *));
50
51 /* Relaxing stuff */
52 static bfd_boolean elf32_avr_relax_section
53 PARAMS((bfd *, asection *, struct bfd_link_info *, bfd_boolean *));
54 static bfd_boolean elf32_avr_relax_delete_bytes
55 PARAMS((bfd *, asection *, bfd_vma, int));
56 static bfd_byte *elf32_avr_get_relocated_section_contents
57 PARAMS((bfd *, struct bfd_link_info *, struct bfd_link_order *,
58 bfd_byte *, bfd_boolean, asymbol **));
59
60 static reloc_howto_type elf_avr_howto_table[] =
61 {
62 HOWTO (R_AVR_NONE, /* type */
63 0, /* rightshift */
64 2, /* size (0 = byte, 1 = short, 2 = long) */
65 32, /* bitsize */
66 FALSE, /* pc_relative */
67 0, /* bitpos */
68 complain_overflow_bitfield, /* complain_on_overflow */
69 bfd_elf_generic_reloc, /* special_function */
70 "R_AVR_NONE", /* name */
71 FALSE, /* partial_inplace */
72 0, /* src_mask */
73 0, /* dst_mask */
74 FALSE), /* pcrel_offset */
75
76 HOWTO (R_AVR_32, /* type */
77 0, /* rightshift */
78 2, /* size (0 = byte, 1 = short, 2 = long) */
79 32, /* bitsize */
80 FALSE, /* pc_relative */
81 0, /* bitpos */
82 complain_overflow_bitfield, /* complain_on_overflow */
83 bfd_elf_generic_reloc, /* special_function */
84 "R_AVR_32", /* name */
85 FALSE, /* partial_inplace */
86 0xffffffff, /* src_mask */
87 0xffffffff, /* dst_mask */
88 FALSE), /* pcrel_offset */
89
90 /* A 7 bit PC relative relocation. */
91 HOWTO (R_AVR_7_PCREL, /* type */
92 1, /* rightshift */
93 1, /* size (0 = byte, 1 = short, 2 = long) */
94 7, /* bitsize */
95 TRUE, /* pc_relative */
96 3, /* bitpos */
97 complain_overflow_bitfield, /* complain_on_overflow */
98 bfd_elf_generic_reloc, /* special_function */
99 "R_AVR_7_PCREL", /* name */
100 FALSE, /* partial_inplace */
101 0xffff, /* src_mask */
102 0xffff, /* dst_mask */
103 TRUE), /* pcrel_offset */
104
105 /* A 13 bit PC relative relocation. */
106 HOWTO (R_AVR_13_PCREL, /* type */
107 1, /* rightshift */
108 1, /* size (0 = byte, 1 = short, 2 = long) */
109 13, /* bitsize */
110 TRUE, /* pc_relative */
111 0, /* bitpos */
112 complain_overflow_bitfield, /* complain_on_overflow */
113 bfd_elf_generic_reloc, /* special_function */
114 "R_AVR_13_PCREL", /* name */
115 FALSE, /* partial_inplace */
116 0xfff, /* src_mask */
117 0xfff, /* dst_mask */
118 TRUE), /* pcrel_offset */
119
120 /* A 16 bit absolute relocation. */
121 HOWTO (R_AVR_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_dont, /* complain_on_overflow */
128 bfd_elf_generic_reloc, /* special_function */
129 "R_AVR_16", /* name */
130 FALSE, /* partial_inplace */
131 0xffff, /* src_mask */
132 0xffff, /* dst_mask */
133 FALSE), /* pcrel_offset */
134
135 /* A 16 bit absolute relocation for command address. */
136 HOWTO (R_AVR_16_PM, /* type */
137 1, /* rightshift */
138 1, /* size (0 = byte, 1 = short, 2 = long) */
139 16, /* bitsize */
140 FALSE, /* pc_relative */
141 0, /* bitpos */
142 complain_overflow_bitfield, /* complain_on_overflow */
143 bfd_elf_generic_reloc, /* special_function */
144 "R_AVR_16_PM", /* name */
145 FALSE, /* partial_inplace */
146 0xffff, /* src_mask */
147 0xffff, /* dst_mask */
148 FALSE), /* pcrel_offset */
149 /* A low 8 bit absolute relocation of 16 bit address.
150 For LDI command. */
151 HOWTO (R_AVR_LO8_LDI, /* type */
152 0, /* rightshift */
153 1, /* size (0 = byte, 1 = short, 2 = long) */
154 8, /* bitsize */
155 FALSE, /* pc_relative */
156 0, /* bitpos */
157 complain_overflow_dont, /* complain_on_overflow */
158 bfd_elf_generic_reloc, /* special_function */
159 "R_AVR_LO8_LDI", /* name */
160 FALSE, /* partial_inplace */
161 0xffff, /* src_mask */
162 0xffff, /* dst_mask */
163 FALSE), /* pcrel_offset */
164 /* A high 8 bit absolute relocation of 16 bit address.
165 For LDI command. */
166 HOWTO (R_AVR_HI8_LDI, /* type */
167 8, /* rightshift */
168 1, /* size (0 = byte, 1 = short, 2 = long) */
169 8, /* bitsize */
170 FALSE, /* pc_relative */
171 0, /* bitpos */
172 complain_overflow_dont, /* complain_on_overflow */
173 bfd_elf_generic_reloc, /* special_function */
174 "R_AVR_HI8_LDI", /* name */
175 FALSE, /* partial_inplace */
176 0xffff, /* src_mask */
177 0xffff, /* dst_mask */
178 FALSE), /* pcrel_offset */
179 /* A high 6 bit absolute relocation of 22 bit address.
180 For LDI command. As well second most significant 8 bit value of
181 a 32 bit link-time constant. */
182 HOWTO (R_AVR_HH8_LDI, /* type */
183 16, /* rightshift */
184 1, /* size (0 = byte, 1 = short, 2 = long) */
185 8, /* bitsize */
186 FALSE, /* pc_relative */
187 0, /* bitpos */
188 complain_overflow_dont, /* complain_on_overflow */
189 bfd_elf_generic_reloc, /* special_function */
190 "R_AVR_HH8_LDI", /* name */
191 FALSE, /* partial_inplace */
192 0xffff, /* src_mask */
193 0xffff, /* dst_mask */
194 FALSE), /* pcrel_offset */
195 /* A negative low 8 bit absolute relocation of 16 bit address.
196 For LDI command. */
197 HOWTO (R_AVR_LO8_LDI_NEG, /* type */
198 0, /* rightshift */
199 1, /* size (0 = byte, 1 = short, 2 = long) */
200 8, /* bitsize */
201 FALSE, /* pc_relative */
202 0, /* bitpos */
203 complain_overflow_dont, /* complain_on_overflow */
204 bfd_elf_generic_reloc, /* special_function */
205 "R_AVR_LO8_LDI_NEG", /* name */
206 FALSE, /* partial_inplace */
207 0xffff, /* src_mask */
208 0xffff, /* dst_mask */
209 FALSE), /* pcrel_offset */
210 /* A negative high 8 bit absolute relocation of 16 bit address.
211 For LDI command. */
212 HOWTO (R_AVR_HI8_LDI_NEG, /* type */
213 8, /* rightshift */
214 1, /* size (0 = byte, 1 = short, 2 = long) */
215 8, /* bitsize */
216 FALSE, /* pc_relative */
217 0, /* bitpos */
218 complain_overflow_dont, /* complain_on_overflow */
219 bfd_elf_generic_reloc, /* special_function */
220 "R_AVR_HI8_LDI_NEG", /* name */
221 FALSE, /* partial_inplace */
222 0xffff, /* src_mask */
223 0xffff, /* dst_mask */
224 FALSE), /* pcrel_offset */
225 /* A negative high 6 bit absolute relocation of 22 bit address.
226 For LDI command. */
227 HOWTO (R_AVR_HH8_LDI_NEG, /* type */
228 16, /* rightshift */
229 1, /* size (0 = byte, 1 = short, 2 = long) */
230 8, /* bitsize */
231 FALSE, /* pc_relative */
232 0, /* bitpos */
233 complain_overflow_dont, /* complain_on_overflow */
234 bfd_elf_generic_reloc, /* special_function */
235 "R_AVR_HH8_LDI_NEG", /* name */
236 FALSE, /* partial_inplace */
237 0xffff, /* src_mask */
238 0xffff, /* dst_mask */
239 FALSE), /* pcrel_offset */
240 /* A low 8 bit absolute relocation of 24 bit program memory address.
241 For LDI command. */
242 HOWTO (R_AVR_LO8_LDI_PM, /* type */
243 1, /* rightshift */
244 1, /* size (0 = byte, 1 = short, 2 = long) */
245 8, /* bitsize */
246 FALSE, /* pc_relative */
247 0, /* bitpos */
248 complain_overflow_dont, /* complain_on_overflow */
249 bfd_elf_generic_reloc, /* special_function */
250 "R_AVR_LO8_LDI_PM", /* name */
251 FALSE, /* partial_inplace */
252 0xffff, /* src_mask */
253 0xffff, /* dst_mask */
254 FALSE), /* pcrel_offset */
255 /* A high 8 bit absolute relocation of 16 bit program memory address.
256 For LDI command. */
257 HOWTO (R_AVR_HI8_LDI_PM, /* type */
258 9, /* rightshift */
259 1, /* size (0 = byte, 1 = short, 2 = long) */
260 8, /* bitsize */
261 FALSE, /* pc_relative */
262 0, /* bitpos */
263 complain_overflow_dont, /* complain_on_overflow */
264 bfd_elf_generic_reloc, /* special_function */
265 "R_AVR_HI8_LDI_PM", /* name */
266 FALSE, /* partial_inplace */
267 0xffff, /* src_mask */
268 0xffff, /* dst_mask */
269 FALSE), /* pcrel_offset */
270 /* A high 8 bit absolute relocation of 24 bit program memory address.
271 For LDI command. */
272 HOWTO (R_AVR_HH8_LDI_PM, /* type */
273 17, /* rightshift */
274 1, /* size (0 = byte, 1 = short, 2 = long) */
275 8, /* bitsize */
276 FALSE, /* pc_relative */
277 0, /* bitpos */
278 complain_overflow_dont, /* complain_on_overflow */
279 bfd_elf_generic_reloc, /* special_function */
280 "R_AVR_HH8_LDI_PM", /* name */
281 FALSE, /* partial_inplace */
282 0xffff, /* src_mask */
283 0xffff, /* dst_mask */
284 FALSE), /* pcrel_offset */
285 /* A low 8 bit absolute relocation of a negative 24 bit
286 program memory address. For LDI command. */
287 HOWTO (R_AVR_LO8_LDI_PM_NEG, /* type */
288 1, /* rightshift */
289 1, /* size (0 = byte, 1 = short, 2 = long) */
290 8, /* bitsize */
291 FALSE, /* pc_relative */
292 0, /* bitpos */
293 complain_overflow_dont, /* complain_on_overflow */
294 bfd_elf_generic_reloc, /* special_function */
295 "R_AVR_LO8_LDI_PM_NEG", /* name */
296 FALSE, /* partial_inplace */
297 0xffff, /* src_mask */
298 0xffff, /* dst_mask */
299 FALSE), /* pcrel_offset */
300 /* A high 8 bit absolute relocation of a negative 16 bit
301 program memory address. For LDI command. */
302 HOWTO (R_AVR_HI8_LDI_PM_NEG, /* type */
303 9, /* rightshift */
304 1, /* size (0 = byte, 1 = short, 2 = long) */
305 8, /* bitsize */
306 FALSE, /* pc_relative */
307 0, /* bitpos */
308 complain_overflow_dont, /* complain_on_overflow */
309 bfd_elf_generic_reloc, /* special_function */
310 "R_AVR_HI8_LDI_PM_NEG", /* name */
311 FALSE, /* partial_inplace */
312 0xffff, /* src_mask */
313 0xffff, /* dst_mask */
314 FALSE), /* pcrel_offset */
315 /* A high 8 bit absolute relocation of a negative 24 bit
316 program memory address. For LDI command. */
317 HOWTO (R_AVR_HH8_LDI_PM_NEG, /* type */
318 17, /* rightshift */
319 1, /* size (0 = byte, 1 = short, 2 = long) */
320 8, /* bitsize */
321 FALSE, /* pc_relative */
322 0, /* bitpos */
323 complain_overflow_dont, /* complain_on_overflow */
324 bfd_elf_generic_reloc, /* special_function */
325 "R_AVR_HH8_LDI_PM_NEG", /* name */
326 FALSE, /* partial_inplace */
327 0xffff, /* src_mask */
328 0xffff, /* dst_mask */
329 FALSE), /* pcrel_offset */
330 /* Relocation for CALL command in ATmega. */
331 HOWTO (R_AVR_CALL, /* type */
332 1, /* rightshift */
333 2, /* size (0 = byte, 1 = short, 2 = long) */
334 23, /* bitsize */
335 FALSE, /* pc_relative */
336 0, /* bitpos */
337 complain_overflow_dont,/* complain_on_overflow */
338 bfd_elf_generic_reloc, /* special_function */
339 "R_AVR_CALL", /* name */
340 FALSE, /* partial_inplace */
341 0xffffffff, /* src_mask */
342 0xffffffff, /* dst_mask */
343 FALSE), /* pcrel_offset */
344 /* A 16 bit absolute relocation of 16 bit address.
345 For LDI command. */
346 HOWTO (R_AVR_LDI, /* type */
347 0, /* rightshift */
348 1, /* size (0 = byte, 1 = short, 2 = long) */
349 16, /* bitsize */
350 FALSE, /* pc_relative */
351 0, /* bitpos */
352 complain_overflow_dont,/* complain_on_overflow */
353 bfd_elf_generic_reloc, /* special_function */
354 "R_AVR_LDI", /* name */
355 FALSE, /* partial_inplace */
356 0xffff, /* src_mask */
357 0xffff, /* dst_mask */
358 FALSE), /* pcrel_offset */
359 /* A 6 bit absolute relocation of 6 bit offset.
360 For ldd/sdd command. */
361 HOWTO (R_AVR_6, /* type */
362 0, /* rightshift */
363 0, /* size (0 = byte, 1 = short, 2 = long) */
364 6, /* bitsize */
365 FALSE, /* pc_relative */
366 0, /* bitpos */
367 complain_overflow_dont,/* complain_on_overflow */
368 bfd_elf_generic_reloc, /* special_function */
369 "R_AVR_6", /* name */
370 FALSE, /* partial_inplace */
371 0xffff, /* src_mask */
372 0xffff, /* dst_mask */
373 FALSE), /* pcrel_offset */
374 /* A 6 bit absolute relocation of 6 bit offset.
375 For sbiw/adiw command. */
376 HOWTO (R_AVR_6_ADIW, /* type */
377 0, /* rightshift */
378 0, /* size (0 = byte, 1 = short, 2 = long) */
379 6, /* bitsize */
380 FALSE, /* pc_relative */
381 0, /* bitpos */
382 complain_overflow_dont,/* complain_on_overflow */
383 bfd_elf_generic_reloc, /* special_function */
384 "R_AVR_6_ADIW", /* name */
385 FALSE, /* partial_inplace */
386 0xffff, /* src_mask */
387 0xffff, /* dst_mask */
388 FALSE), /* pcrel_offset */
389 /* Most significant 8 bit value of a 32 bit link-time constant. */
390 HOWTO (R_AVR_MS8_LDI, /* type */
391 24, /* rightshift */
392 1, /* size (0 = byte, 1 = short, 2 = long) */
393 8, /* bitsize */
394 FALSE, /* pc_relative */
395 0, /* bitpos */
396 complain_overflow_dont, /* complain_on_overflow */
397 bfd_elf_generic_reloc, /* special_function */
398 "R_AVR_MS8_LDI", /* name */
399 FALSE, /* partial_inplace */
400 0xffff, /* src_mask */
401 0xffff, /* dst_mask */
402 FALSE), /* pcrel_offset */
403 /* Negative most significant 8 bit value of a 32 bit link-time constant. */
404 HOWTO (R_AVR_MS8_LDI_NEG, /* type */
405 24, /* rightshift */
406 1, /* size (0 = byte, 1 = short, 2 = long) */
407 8, /* bitsize */
408 FALSE, /* pc_relative */
409 0, /* bitpos */
410 complain_overflow_dont, /* complain_on_overflow */
411 bfd_elf_generic_reloc, /* special_function */
412 "R_AVR_MS8_LDI_NEG", /* name */
413 FALSE, /* partial_inplace */
414 0xffff, /* src_mask */
415 0xffff, /* dst_mask */
416 FALSE) /* pcrel_offset */
417 };
418
419 /* Map BFD reloc types to AVR ELF reloc types. */
420
421 struct avr_reloc_map
422 {
423 bfd_reloc_code_real_type bfd_reloc_val;
424 unsigned int elf_reloc_val;
425 };
426
427 static const struct avr_reloc_map avr_reloc_map[] =
428 {
429 { BFD_RELOC_NONE, R_AVR_NONE },
430 { BFD_RELOC_32, R_AVR_32 },
431 { BFD_RELOC_AVR_7_PCREL, R_AVR_7_PCREL },
432 { BFD_RELOC_AVR_13_PCREL, R_AVR_13_PCREL },
433 { BFD_RELOC_16, R_AVR_16 },
434 { BFD_RELOC_AVR_16_PM, R_AVR_16_PM },
435 { BFD_RELOC_AVR_LO8_LDI, R_AVR_LO8_LDI},
436 { BFD_RELOC_AVR_HI8_LDI, R_AVR_HI8_LDI },
437 { BFD_RELOC_AVR_HH8_LDI, R_AVR_HH8_LDI },
438 { BFD_RELOC_AVR_MS8_LDI, R_AVR_MS8_LDI },
439 { BFD_RELOC_AVR_LO8_LDI_NEG, R_AVR_LO8_LDI_NEG },
440 { BFD_RELOC_AVR_HI8_LDI_NEG, R_AVR_HI8_LDI_NEG },
441 { BFD_RELOC_AVR_HH8_LDI_NEG, R_AVR_HH8_LDI_NEG },
442 { BFD_RELOC_AVR_MS8_LDI_NEG, R_AVR_MS8_LDI_NEG },
443 { BFD_RELOC_AVR_LO8_LDI_PM, R_AVR_LO8_LDI_PM },
444 { BFD_RELOC_AVR_HI8_LDI_PM, R_AVR_HI8_LDI_PM },
445 { BFD_RELOC_AVR_HH8_LDI_PM, R_AVR_HH8_LDI_PM },
446 { BFD_RELOC_AVR_LO8_LDI_PM_NEG, R_AVR_LO8_LDI_PM_NEG },
447 { BFD_RELOC_AVR_HI8_LDI_PM_NEG, R_AVR_HI8_LDI_PM_NEG },
448 { BFD_RELOC_AVR_HH8_LDI_PM_NEG, R_AVR_HH8_LDI_PM_NEG },
449 { BFD_RELOC_AVR_CALL, R_AVR_CALL },
450 { BFD_RELOC_AVR_LDI, R_AVR_LDI },
451 { BFD_RELOC_AVR_6, R_AVR_6 },
452 { BFD_RELOC_AVR_6_ADIW, R_AVR_6_ADIW }
453 };
454
455 /* Meant to be filled one day with the wrap around address for the
456 specific device. I.e. should get the value 0x4000 for 16k devices,
457 0x8000 for 32k devices and so on.
458
459 We initialize it here with a value of 0x1000000 resulting in
460 that we will never suggest a wrap-around jump during relaxation.
461 The logic of the source code later on assumes that in
462 avr_pc_wrap_around one single bit is set. */
463
464 unsigned int avr_pc_wrap_around = 0x10000000;
465
466 /* Calculates the effective distance of a pc relative jump/call. */
467 static int
468 avr_relative_distance_considering_wrap_around (unsigned int distance)
469 {
470 unsigned int wrap_around_mask = avr_pc_wrap_around - 1;
471
472 int dist_with_wrap_around = distance & wrap_around_mask;
473
474 if (dist_with_wrap_around > ((int) (avr_pc_wrap_around >> 1)) )
475 dist_with_wrap_around -= avr_pc_wrap_around;
476
477 return dist_with_wrap_around;
478 }
479
480
481 static reloc_howto_type *
482 bfd_elf32_bfd_reloc_type_lookup (abfd, code)
483 bfd *abfd ATTRIBUTE_UNUSED;
484 bfd_reloc_code_real_type code;
485 {
486 unsigned int i;
487
488 for (i = 0;
489 i < sizeof (avr_reloc_map) / sizeof (struct avr_reloc_map);
490 i++)
491 {
492 if (avr_reloc_map[i].bfd_reloc_val == code)
493 return &elf_avr_howto_table[avr_reloc_map[i].elf_reloc_val];
494 }
495
496 return NULL;
497 }
498
499 /* Set the howto pointer for an AVR ELF reloc. */
500
501 static void
502 avr_info_to_howto_rela (abfd, cache_ptr, dst)
503 bfd *abfd ATTRIBUTE_UNUSED;
504 arelent *cache_ptr;
505 Elf_Internal_Rela *dst;
506 {
507 unsigned int r_type;
508
509 r_type = ELF32_R_TYPE (dst->r_info);
510 BFD_ASSERT (r_type < (unsigned int) R_AVR_max);
511 cache_ptr->howto = &elf_avr_howto_table[r_type];
512 }
513
514 static asection *
515 elf32_avr_gc_mark_hook (sec, info, rel, h, sym)
516 asection *sec;
517 struct bfd_link_info *info ATTRIBUTE_UNUSED;
518 Elf_Internal_Rela *rel;
519 struct elf_link_hash_entry *h;
520 Elf_Internal_Sym *sym;
521 {
522 if (h != NULL)
523 {
524 switch (ELF32_R_TYPE (rel->r_info))
525 {
526 default:
527 switch (h->root.type)
528 {
529 case bfd_link_hash_defined:
530 case bfd_link_hash_defweak:
531 return h->root.u.def.section;
532
533 case bfd_link_hash_common:
534 return h->root.u.c.p->section;
535
536 default:
537 break;
538 }
539 }
540 }
541 else
542 return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
543
544 return NULL;
545 }
546
547 static bfd_boolean
548 elf32_avr_gc_sweep_hook (abfd, info, sec, relocs)
549 bfd *abfd ATTRIBUTE_UNUSED;
550 struct bfd_link_info *info ATTRIBUTE_UNUSED;
551 asection *sec ATTRIBUTE_UNUSED;
552 const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED;
553 {
554 /* We don't use got and plt entries for avr. */
555 return TRUE;
556 }
557
558 /* Look through the relocs for a section during the first phase.
559 Since we don't do .gots or .plts, we just need to consider the
560 virtual table relocs for gc. */
561
562 static bfd_boolean
563 elf32_avr_check_relocs (abfd, info, sec, relocs)
564 bfd *abfd;
565 struct bfd_link_info *info;
566 asection *sec;
567 const Elf_Internal_Rela *relocs;
568 {
569 Elf_Internal_Shdr *symtab_hdr;
570 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
571 const Elf_Internal_Rela *rel;
572 const Elf_Internal_Rela *rel_end;
573
574 if (info->relocatable)
575 return TRUE;
576
577 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
578 sym_hashes = elf_sym_hashes (abfd);
579 sym_hashes_end = sym_hashes + symtab_hdr->sh_size/sizeof (Elf32_External_Sym);
580 if (!elf_bad_symtab (abfd))
581 sym_hashes_end -= symtab_hdr->sh_info;
582
583 rel_end = relocs + sec->reloc_count;
584 for (rel = relocs; rel < rel_end; rel++)
585 {
586 struct elf_link_hash_entry *h;
587 unsigned long r_symndx;
588
589 r_symndx = ELF32_R_SYM (rel->r_info);
590 if (r_symndx < symtab_hdr->sh_info)
591 h = NULL;
592 else
593 {
594 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
595 while (h->root.type == bfd_link_hash_indirect
596 || h->root.type == bfd_link_hash_warning)
597 h = (struct elf_link_hash_entry *) h->root.u.i.link;
598 }
599 }
600
601 return TRUE;
602 }
603
604 /* Perform a single relocation. By default we use the standard BFD
605 routines, but a few relocs, we have to do them ourselves. */
606
607 static bfd_reloc_status_type
608 avr_final_link_relocate (howto, input_bfd, input_section,
609 contents, rel, relocation)
610 reloc_howto_type * howto;
611 bfd * input_bfd;
612 asection * input_section;
613 bfd_byte * contents;
614 Elf_Internal_Rela * rel;
615 bfd_vma relocation;
616 {
617 bfd_reloc_status_type r = bfd_reloc_ok;
618 bfd_vma x;
619 bfd_signed_vma srel;
620
621 switch (howto->type)
622 {
623 case R_AVR_7_PCREL:
624 contents += rel->r_offset;
625 srel = (bfd_signed_vma) relocation;
626 srel += rel->r_addend;
627 srel -= rel->r_offset;
628 srel -= 2; /* Branch instructions add 2 to the PC... */
629 srel -= (input_section->output_section->vma +
630 input_section->output_offset);
631
632 if (srel & 1)
633 return bfd_reloc_outofrange;
634 if (srel > ((1 << 7) - 1) || (srel < - (1 << 7)))
635 return bfd_reloc_overflow;
636 x = bfd_get_16 (input_bfd, contents);
637 x = (x & 0xfc07) | (((srel >> 1) << 3) & 0x3f8);
638 bfd_put_16 (input_bfd, x, contents);
639 break;
640
641 case R_AVR_13_PCREL:
642 contents += rel->r_offset;
643 srel = (bfd_signed_vma) relocation;
644 srel += rel->r_addend;
645 srel -= rel->r_offset;
646 srel -= 2; /* Branch instructions add 2 to the PC... */
647 srel -= (input_section->output_section->vma +
648 input_section->output_offset);
649
650 if (srel & 1)
651 return bfd_reloc_outofrange;
652
653 srel = avr_relative_distance_considering_wrap_around (srel);
654
655 /* AVR addresses commands as words. */
656 srel >>= 1;
657
658 /* Check for overflow. */
659 if (srel < -2048 || srel > 2047)
660 {
661 /* Relative distance is too large. */
662
663 /* Always apply WRAPAROUND for avr2 and avr4. */
664 switch (bfd_get_mach (input_bfd))
665 {
666 case bfd_mach_avr2:
667 case bfd_mach_avr4:
668 break;
669
670 default:
671 return bfd_reloc_overflow;
672 }
673 }
674
675 x = bfd_get_16 (input_bfd, contents);
676 x = (x & 0xf000) | (srel & 0xfff);
677 bfd_put_16 (input_bfd, x, contents);
678 break;
679
680 case R_AVR_LO8_LDI:
681 contents += rel->r_offset;
682 srel = (bfd_signed_vma) relocation + rel->r_addend;
683 x = bfd_get_16 (input_bfd, contents);
684 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
685 bfd_put_16 (input_bfd, x, contents);
686 break;
687
688 case R_AVR_LDI:
689 contents += rel->r_offset;
690 srel = (bfd_signed_vma) relocation + rel->r_addend;
691 if ( ((srel > 0) && (srel & 0xffff) > 255)
692 || ((srel < 0) && ( (-srel) & 0xffff) > 128))
693 /* Remove offset for data/eeprom section. */
694 return bfd_reloc_overflow;
695
696 x = bfd_get_16 (input_bfd, contents);
697 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
698 bfd_put_16 (input_bfd, x, contents);
699 break;
700
701 case R_AVR_6:
702 contents += rel->r_offset;
703 srel = (bfd_signed_vma) relocation + rel->r_addend;
704 if (((srel & 0xffff) > 63) || (srel < 0))
705 /* Remove offset for data/eeprom section. */
706 return bfd_reloc_overflow;
707 x = bfd_get_16 (input_bfd, contents);
708 x = (x & 0xd3f8) | ((srel & 7) | ((srel & (3 << 3)) << 7)
709 | ((srel & (1 << 5)) << 8));
710 bfd_put_16 (input_bfd, x, contents);
711 break;
712
713 case R_AVR_6_ADIW:
714 contents += rel->r_offset;
715 srel = (bfd_signed_vma) relocation + rel->r_addend;
716 if (((srel & 0xffff) > 63) || (srel < 0))
717 /* Remove offset for data/eeprom section. */
718 return bfd_reloc_overflow;
719 x = bfd_get_16 (input_bfd, contents);
720 x = (x & 0xff30) | (srel & 0xf) | ((srel & 0x30) << 2);
721 bfd_put_16 (input_bfd, x, contents);
722 break;
723
724 case R_AVR_HI8_LDI:
725 contents += rel->r_offset;
726 srel = (bfd_signed_vma) relocation + rel->r_addend;
727 srel = (srel >> 8) & 0xff;
728 x = bfd_get_16 (input_bfd, contents);
729 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
730 bfd_put_16 (input_bfd, x, contents);
731 break;
732
733 case R_AVR_HH8_LDI:
734 contents += rel->r_offset;
735 srel = (bfd_signed_vma) relocation + rel->r_addend;
736 srel = (srel >> 16) & 0xff;
737 x = bfd_get_16 (input_bfd, contents);
738 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
739 bfd_put_16 (input_bfd, x, contents);
740 break;
741
742 case R_AVR_MS8_LDI:
743 contents += rel->r_offset;
744 srel = (bfd_signed_vma) relocation + rel->r_addend;
745 srel = (srel >> 24) & 0xff;
746 x = bfd_get_16 (input_bfd, contents);
747 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
748 bfd_put_16 (input_bfd, x, contents);
749 break;
750
751 case R_AVR_LO8_LDI_NEG:
752 contents += rel->r_offset;
753 srel = (bfd_signed_vma) relocation + rel->r_addend;
754 srel = -srel;
755 x = bfd_get_16 (input_bfd, contents);
756 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
757 bfd_put_16 (input_bfd, x, contents);
758 break;
759
760 case R_AVR_HI8_LDI_NEG:
761 contents += rel->r_offset;
762 srel = (bfd_signed_vma) relocation + rel->r_addend;
763 srel = -srel;
764 srel = (srel >> 8) & 0xff;
765 x = bfd_get_16 (input_bfd, contents);
766 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
767 bfd_put_16 (input_bfd, x, contents);
768 break;
769
770 case R_AVR_HH8_LDI_NEG:
771 contents += rel->r_offset;
772 srel = (bfd_signed_vma) relocation + rel->r_addend;
773 srel = -srel;
774 srel = (srel >> 16) & 0xff;
775 x = bfd_get_16 (input_bfd, contents);
776 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
777 bfd_put_16 (input_bfd, x, contents);
778 break;
779
780 case R_AVR_MS8_LDI_NEG:
781 contents += rel->r_offset;
782 srel = (bfd_signed_vma) relocation + rel->r_addend;
783 srel = -srel;
784 srel = (srel >> 24) & 0xff;
785 x = bfd_get_16 (input_bfd, contents);
786 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
787 bfd_put_16 (input_bfd, x, contents);
788 break;
789
790 case R_AVR_LO8_LDI_PM:
791 contents += rel->r_offset;
792 srel = (bfd_signed_vma) relocation + rel->r_addend;
793 if (srel & 1)
794 return bfd_reloc_outofrange;
795 srel = srel >> 1;
796 x = bfd_get_16 (input_bfd, contents);
797 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
798 bfd_put_16 (input_bfd, x, contents);
799 break;
800
801 case R_AVR_HI8_LDI_PM:
802 contents += rel->r_offset;
803 srel = (bfd_signed_vma) relocation + rel->r_addend;
804 if (srel & 1)
805 return bfd_reloc_outofrange;
806 srel = srel >> 1;
807 srel = (srel >> 8) & 0xff;
808 x = bfd_get_16 (input_bfd, contents);
809 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
810 bfd_put_16 (input_bfd, x, contents);
811 break;
812
813 case R_AVR_HH8_LDI_PM:
814 contents += rel->r_offset;
815 srel = (bfd_signed_vma) relocation + rel->r_addend;
816 if (srel & 1)
817 return bfd_reloc_outofrange;
818 srel = srel >> 1;
819 srel = (srel >> 16) & 0xff;
820 x = bfd_get_16 (input_bfd, contents);
821 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
822 bfd_put_16 (input_bfd, x, contents);
823 break;
824
825 case R_AVR_LO8_LDI_PM_NEG:
826 contents += rel->r_offset;
827 srel = (bfd_signed_vma) relocation + rel->r_addend;
828 srel = -srel;
829 if (srel & 1)
830 return bfd_reloc_outofrange;
831 srel = srel >> 1;
832 x = bfd_get_16 (input_bfd, contents);
833 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
834 bfd_put_16 (input_bfd, x, contents);
835 break;
836
837 case R_AVR_HI8_LDI_PM_NEG:
838 contents += rel->r_offset;
839 srel = (bfd_signed_vma) relocation + rel->r_addend;
840 srel = -srel;
841 if (srel & 1)
842 return bfd_reloc_outofrange;
843 srel = srel >> 1;
844 srel = (srel >> 8) & 0xff;
845 x = bfd_get_16 (input_bfd, contents);
846 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
847 bfd_put_16 (input_bfd, x, contents);
848 break;
849
850 case R_AVR_HH8_LDI_PM_NEG:
851 contents += rel->r_offset;
852 srel = (bfd_signed_vma) relocation + rel->r_addend;
853 srel = -srel;
854 if (srel & 1)
855 return bfd_reloc_outofrange;
856 srel = srel >> 1;
857 srel = (srel >> 16) & 0xff;
858 x = bfd_get_16 (input_bfd, contents);
859 x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
860 bfd_put_16 (input_bfd, x, contents);
861 break;
862
863 case R_AVR_CALL:
864 contents += rel->r_offset;
865 srel = (bfd_signed_vma) relocation + rel->r_addend;
866 if (srel & 1)
867 return bfd_reloc_outofrange;
868 srel = srel >> 1;
869 x = bfd_get_16 (input_bfd, contents);
870 x |= ((srel & 0x10000) | ((srel << 3) & 0x1f00000)) >> 16;
871 bfd_put_16 (input_bfd, x, contents);
872 bfd_put_16 (input_bfd, (bfd_vma) srel & 0xffff, contents+2);
873 break;
874
875 default:
876 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
877 contents, rel->r_offset,
878 relocation, rel->r_addend);
879 }
880
881 return r;
882 }
883
884 /* Relocate an AVR ELF section. */
885 static bfd_boolean
886 elf32_avr_relocate_section (output_bfd, info, input_bfd, input_section,
887 contents, relocs, local_syms, local_sections)
888 bfd *output_bfd ATTRIBUTE_UNUSED;
889 struct bfd_link_info *info;
890 bfd *input_bfd;
891 asection *input_section;
892 bfd_byte *contents;
893 Elf_Internal_Rela *relocs;
894 Elf_Internal_Sym *local_syms;
895 asection **local_sections;
896 {
897 Elf_Internal_Shdr * symtab_hdr;
898 struct elf_link_hash_entry ** sym_hashes;
899 Elf_Internal_Rela * rel;
900 Elf_Internal_Rela * relend;
901
902 if (info->relocatable)
903 return TRUE;
904
905 symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
906 sym_hashes = elf_sym_hashes (input_bfd);
907 relend = relocs + input_section->reloc_count;
908
909 for (rel = relocs; rel < relend; rel ++)
910 {
911 reloc_howto_type * howto;
912 unsigned long r_symndx;
913 Elf_Internal_Sym * sym;
914 asection * sec;
915 struct elf_link_hash_entry * h;
916 bfd_vma relocation;
917 bfd_reloc_status_type r;
918 const char * name;
919 int r_type;
920
921 /* This is a final link. */
922 r_type = ELF32_R_TYPE (rel->r_info);
923 r_symndx = ELF32_R_SYM (rel->r_info);
924 howto = elf_avr_howto_table + ELF32_R_TYPE (rel->r_info);
925 h = NULL;
926 sym = NULL;
927 sec = NULL;
928
929 if (r_symndx < symtab_hdr->sh_info)
930 {
931 sym = local_syms + r_symndx;
932 sec = local_sections [r_symndx];
933 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
934
935 name = bfd_elf_string_from_elf_section
936 (input_bfd, symtab_hdr->sh_link, sym->st_name);
937 name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
938 }
939 else
940 {
941 bfd_boolean unresolved_reloc, warned;
942
943 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
944 r_symndx, symtab_hdr, sym_hashes,
945 h, sec, relocation,
946 unresolved_reloc, warned);
947
948 name = h->root.root.string;
949 }
950
951 r = avr_final_link_relocate (howto, input_bfd, input_section,
952 contents, rel, relocation);
953
954 if (r != bfd_reloc_ok)
955 {
956 const char * msg = (const char *) NULL;
957
958 switch (r)
959 {
960 case bfd_reloc_overflow:
961 r = info->callbacks->reloc_overflow
962 (info, (h ? &h->root : NULL),
963 name, howto->name, (bfd_vma) 0,
964 input_bfd, input_section, rel->r_offset);
965 break;
966
967 case bfd_reloc_undefined:
968 r = info->callbacks->undefined_symbol
969 (info, name, input_bfd, input_section, rel->r_offset, TRUE);
970 break;
971
972 case bfd_reloc_outofrange:
973 msg = _("internal error: out of range error");
974 break;
975
976 case bfd_reloc_notsupported:
977 msg = _("internal error: unsupported relocation error");
978 break;
979
980 case bfd_reloc_dangerous:
981 msg = _("internal error: dangerous relocation");
982 break;
983
984 default:
985 msg = _("internal error: unknown error");
986 break;
987 }
988
989 if (msg)
990 r = info->callbacks->warning
991 (info, msg, name, input_bfd, input_section, rel->r_offset);
992
993 if (! r)
994 return FALSE;
995 }
996 }
997
998 return TRUE;
999 }
1000
1001 /* The final processing done just before writing out a AVR ELF object
1002 file. This gets the AVR architecture right based on the machine
1003 number. */
1004
1005 static void
1006 bfd_elf_avr_final_write_processing (abfd, linker)
1007 bfd *abfd;
1008 bfd_boolean linker ATTRIBUTE_UNUSED;
1009 {
1010 unsigned long val;
1011
1012 switch (bfd_get_mach (abfd))
1013 {
1014 default:
1015 case bfd_mach_avr2:
1016 val = E_AVR_MACH_AVR2;
1017 break;
1018
1019 case bfd_mach_avr1:
1020 val = E_AVR_MACH_AVR1;
1021 break;
1022
1023 case bfd_mach_avr3:
1024 val = E_AVR_MACH_AVR3;
1025 break;
1026
1027 case bfd_mach_avr4:
1028 val = E_AVR_MACH_AVR4;
1029 break;
1030
1031 case bfd_mach_avr5:
1032 val = E_AVR_MACH_AVR5;
1033 break;
1034 }
1035
1036 elf_elfheader (abfd)->e_machine = EM_AVR;
1037 elf_elfheader (abfd)->e_flags &= ~ EF_AVR_MACH;
1038 elf_elfheader (abfd)->e_flags |= val;
1039 elf_elfheader (abfd)->e_flags |= EF_AVR_LINKRELAX_PREPARED;
1040 }
1041
1042 /* Set the right machine number. */
1043
1044 static bfd_boolean
1045 elf32_avr_object_p (abfd)
1046 bfd *abfd;
1047 {
1048 unsigned int e_set = bfd_mach_avr2;
1049 if (elf_elfheader (abfd)->e_machine == EM_AVR
1050 || elf_elfheader (abfd)->e_machine == EM_AVR_OLD)
1051 {
1052 int e_mach = elf_elfheader (abfd)->e_flags & EF_AVR_MACH;
1053 switch (e_mach)
1054 {
1055 default:
1056 case E_AVR_MACH_AVR2:
1057 e_set = bfd_mach_avr2;
1058 break;
1059
1060 case E_AVR_MACH_AVR1:
1061 e_set = bfd_mach_avr1;
1062 break;
1063
1064 case E_AVR_MACH_AVR3:
1065 e_set = bfd_mach_avr3;
1066 break;
1067
1068 case E_AVR_MACH_AVR4:
1069 e_set = bfd_mach_avr4;
1070 break;
1071
1072 case E_AVR_MACH_AVR5:
1073 e_set = bfd_mach_avr5;
1074 break;
1075 }
1076 }
1077 return bfd_default_set_arch_mach (abfd, bfd_arch_avr,
1078 e_set);
1079 }
1080
1081
1082 /* Enable debugging printout at stdout with a value of 1. */
1083 #define DEBUG_RELAX 0
1084
1085 /* This function handles relaxing for the avr.
1086 Many important relaxing opportunities within functions are already
1087 realized by the compiler itself.
1088 Here we try to replace call (4 bytes) -> rcall (2 bytes)
1089 and jump -> rjmp (safes also 2 bytes).
1090 As well we now optimize seqences of
1091 - call/rcall function
1092 - ret
1093 to yield
1094 - jmp/rjmp function
1095 - ret
1096 . In case that within a sequence
1097 - jmp/rjmp label
1098 - ret
1099 the ret could no longer be reached it is optimized away. In order
1100 to check if the ret is no longer needed, it is checked that the ret's address
1101 is not the target of a branch or jump within the same section, it is checked
1102 that there is no skip instruction before the jmp/rjmp and that there
1103 is no local or global label place at the address of the ret.
1104
1105 We refrain from relaxing within sections ".vectors" and
1106 ".jumptables" in order to maintain the position of the instructions.
1107 There, however, we substitute jmp/call by a sequence rjmp,nop/rcall,nop
1108 if possible. (In future one could possibly use the space of the nop
1109 for the first instruction of the irq service function.
1110
1111 The .jumptables sections is meant to be used for a future tablejump variant
1112 for the devices with 3-byte program counter where the table itself
1113 contains 4-byte jump instructions whose relative offset must not
1114 be changed. */
1115
1116 static bfd_boolean
1117 elf32_avr_relax_section (bfd *abfd, asection *sec,
1118 struct bfd_link_info *link_info,
1119 bfd_boolean *again)
1120 {
1121 Elf_Internal_Shdr *symtab_hdr;
1122 Elf_Internal_Rela *internal_relocs;
1123 Elf_Internal_Rela *irel, *irelend;
1124 bfd_byte *contents = NULL;
1125 Elf_Internal_Sym *isymbuf = NULL;
1126 static asection *last_input_section = NULL;
1127 static Elf_Internal_Rela *last_reloc = NULL;
1128
1129 /* Assume nothing changes. */
1130 *again = FALSE;
1131
1132 /* We don't have to do anything for a relocatable link, if
1133 this section does not have relocs, or if this is not a
1134 code section. */
1135 if (link_info->relocatable
1136 || (sec->flags & SEC_RELOC) == 0
1137 || sec->reloc_count == 0
1138 || (sec->flags & SEC_CODE) == 0)
1139 return TRUE;
1140
1141 /* Check if the object file to relax uses internal symbols so that we
1142 could fix up the relocations. */
1143
1144 if (!(elf_elfheader (abfd)->e_flags & EF_AVR_LINKRELAX_PREPARED))
1145 return TRUE;
1146
1147
1148 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1149
1150 /* Get a copy of the native relocations. */
1151 internal_relocs = (_bfd_elf_link_read_relocs
1152 (abfd, sec, (PTR) NULL, (Elf_Internal_Rela *) NULL,
1153 link_info->keep_memory));
1154 if (internal_relocs == NULL)
1155 goto error_return;
1156
1157 if (sec != last_input_section)
1158 last_reloc = NULL;
1159
1160 last_input_section = sec;
1161
1162 /* Walk through the relocs looking for relaxing opportunities. */
1163 irelend = internal_relocs + sec->reloc_count;
1164 for (irel = internal_relocs; irel < irelend; irel++)
1165 {
1166 bfd_vma symval;
1167
1168 if (ELF32_R_TYPE (irel->r_info) != R_AVR_13_PCREL
1169 && ELF32_R_TYPE (irel->r_info) != R_AVR_7_PCREL
1170 && ELF32_R_TYPE (irel->r_info) != R_AVR_CALL)
1171 continue;
1172
1173 /* Get the section contents if we haven't done so already. */
1174 if (contents == NULL)
1175 {
1176 /* Get cached copy if it exists. */
1177 if (elf_section_data (sec)->this_hdr.contents != NULL)
1178 contents = elf_section_data (sec)->this_hdr.contents;
1179 else
1180 {
1181 /* Go get them off disk. */
1182 if (!bfd_malloc_and_get_section (abfd, sec, &contents))
1183 goto error_return;
1184 }
1185 }
1186
1187 /* Read this BFD's local symbols if we haven't done so already. */
1188 if (isymbuf == NULL && symtab_hdr->sh_info != 0)
1189 {
1190 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
1191 if (isymbuf == NULL)
1192 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
1193 symtab_hdr->sh_info, 0,
1194 NULL, NULL, NULL);
1195 if (isymbuf == NULL)
1196 goto error_return;
1197 }
1198
1199
1200 /* Get the value of the symbol referred to by the reloc. */
1201 if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
1202 {
1203 /* A local symbol. */
1204 Elf_Internal_Sym *isym;
1205 asection *sym_sec;
1206
1207 isym = isymbuf + ELF32_R_SYM (irel->r_info);
1208 sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
1209 symval = isym->st_value;
1210 /* If the reloc is absolute, it will not have
1211 a symbol or section associated with it. */
1212 if (sym_sec)
1213 symval += sym_sec->output_section->vma
1214 + sym_sec->output_offset;
1215 }
1216 else
1217 {
1218 unsigned long indx;
1219 struct elf_link_hash_entry *h;
1220
1221 /* An external symbol. */
1222 indx = ELF32_R_SYM (irel->r_info) - symtab_hdr->sh_info;
1223 h = elf_sym_hashes (abfd)[indx];
1224 BFD_ASSERT (h != NULL);
1225 if (h->root.type != bfd_link_hash_defined
1226 && h->root.type != bfd_link_hash_defweak)
1227 {
1228 /* This appears to be a reference to an undefined
1229 symbol. Just ignore it--it will be caught by the
1230 regular reloc processing. */
1231 continue;
1232 }
1233 symval = (h->root.u.def.value
1234 + h->root.u.def.section->output_section->vma
1235 + h->root.u.def.section->output_offset);
1236 }
1237
1238 /* For simplicity of coding, we are going to modify the section
1239 contents, the section relocs, and the BFD symbol table. We
1240 must tell the rest of the code not to free up this
1241 information. It would be possible to instead create a table
1242 of changes which have to be made, as is done in coff-mips.c;
1243 that would be more work, but would require less memory when
1244 the linker is run. */
1245 switch (ELF32_R_TYPE (irel->r_info))
1246 {
1247 /* Try to turn a 22-bit absolute call/jump into an 13-bit
1248 pc-relative rcall/rjmp. */
1249 case R_AVR_CALL:
1250 {
1251 bfd_vma value = symval + irel->r_addend;
1252 bfd_vma dot, gap;
1253 int distance_short_enough = 0;
1254
1255 /* Get the address of this instruction. */
1256 dot = (sec->output_section->vma
1257 + sec->output_offset + irel->r_offset);
1258
1259 /* Compute the distance from this insn to the branch target. */
1260 gap = value - dot;
1261
1262 /* If the distance is within -4094..+4098 inclusive, then we can
1263 relax this jump/call. +4098 because the call/jump target
1264 will be closer after the relaxation. */
1265 if ((int) gap >= -4094 && (int) gap <= 4098)
1266 distance_short_enough = 1;
1267
1268 /* Here we handle the wrap-around case. E.g. for a 16k device
1269 we could use a rjmp to jump from address 0x100 to 0x3d00!
1270 In order to make this work properly, we need to fill the
1271 vaiable avr_pc_wrap_around with the appropriate value.
1272 I.e. 0x4000 for a 16k device. */
1273 {
1274 /* Shrinking the code size makes the gaps larger in the
1275 case of wrap-arounds. So we use a heuristical safety
1276 margin to avoid that during relax the distance gets
1277 again too large for the short jumps. Let's assume
1278 a typical code-size reduction due to relax for a
1279 16k device of 600 bytes. So let's use twice the
1280 typical value as safety margin. */
1281
1282 int rgap;
1283 int safety_margin;
1284
1285 int assumed_shrink = 600;
1286 if (avr_pc_wrap_around > 0x4000)
1287 assumed_shrink = 900;
1288
1289 safety_margin = 2 * assumed_shrink;
1290
1291 rgap = avr_relative_distance_considering_wrap_around (gap);
1292
1293 if (rgap >= (-4092 + safety_margin)
1294 && rgap <= (4094 - safety_margin))
1295 distance_short_enough = 1;
1296 }
1297
1298 if (distance_short_enough)
1299 {
1300 unsigned char code_msb;
1301 unsigned char code_lsb;
1302
1303 if (DEBUG_RELAX)
1304 printf ("shrinking jump/call instruction at address 0x%x"
1305 " in section %s\n\n",
1306 (int) dot, sec->name);
1307
1308 /* Note that we've changed the relocs, section contents,
1309 etc. */
1310 elf_section_data (sec)->relocs = internal_relocs;
1311 elf_section_data (sec)->this_hdr.contents = contents;
1312 symtab_hdr->contents = (unsigned char *) isymbuf;
1313
1314 /* Get the instruction code for relaxing. */
1315 code_lsb = bfd_get_8 (abfd, contents + irel->r_offset);
1316 code_msb = bfd_get_8 (abfd, contents + irel->r_offset + 1);
1317
1318 /* Mask out the relocation bits. */
1319 code_msb &= 0x94;
1320 code_lsb &= 0x0E;
1321 if (code_msb == 0x94 && code_lsb == 0x0E)
1322 {
1323 /* we are changing call -> rcall . */
1324 bfd_put_8 (abfd, 0x00, contents + irel->r_offset);
1325 bfd_put_8 (abfd, 0xD0, contents + irel->r_offset + 1);
1326 }
1327 else if (code_msb == 0x94 && code_lsb == 0x0C)
1328 {
1329 /* we are changeing jump -> rjmp. */
1330 bfd_put_8 (abfd, 0x00, contents + irel->r_offset);
1331 bfd_put_8 (abfd, 0xC0, contents + irel->r_offset + 1);
1332 }
1333 else
1334 abort ();
1335
1336 /* Fix the relocation's type. */
1337 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1338 R_AVR_13_PCREL);
1339
1340 /* Check for the vector section. There we don't want to
1341 modify the ordering! */
1342
1343 if (!strcmp (sec->name,".vectors")
1344 || !strcmp (sec->name,".jumptables"))
1345 {
1346 /* Let's insert a nop. */
1347 bfd_put_8 (abfd, 0x00, contents + irel->r_offset + 2);
1348 bfd_put_8 (abfd, 0x00, contents + irel->r_offset + 3);
1349 }
1350 else
1351 {
1352 /* Delete two bytes of data. */
1353 if (!elf32_avr_relax_delete_bytes (abfd, sec,
1354 irel->r_offset + 2, 2))
1355 goto error_return;
1356
1357 /* That will change things, so, we should relax again.
1358 Note that this is not required, and it may be slow. */
1359 *again = TRUE;
1360 }
1361 }
1362 }
1363 default:
1364 {
1365 unsigned char code_msb;
1366 unsigned char code_lsb;
1367 bfd_vma dot;
1368
1369 code_msb = bfd_get_8 (abfd, contents + irel->r_offset + 1);
1370 code_lsb = bfd_get_8 (abfd, contents + irel->r_offset + 0);
1371
1372 /* Get the address of this instruction. */
1373 dot = (sec->output_section->vma
1374 + sec->output_offset + irel->r_offset);
1375
1376 /* Here we look for rcall/ret or call/ret sequences that could be
1377 safely replaced by rjmp/ret or jmp/ret */
1378 if (0xd0 == (code_msb & 0xf0))
1379 {
1380 /* This insn is a rcall. */
1381 unsigned char next_insn_msb = 0;
1382 unsigned char next_insn_lsb = 0;
1383
1384 if (irel->r_offset + 3 < sec->size)
1385 {
1386 next_insn_msb =
1387 bfd_get_8 (abfd, contents + irel->r_offset + 3);
1388 next_insn_lsb =
1389 bfd_get_8 (abfd, contents + irel->r_offset + 2);
1390 }
1391 if ((0x95 == next_insn_msb) && (0x08 == next_insn_lsb))
1392 {
1393 /* The next insn is a ret. We now convert the rcall insn
1394 into a rjmp instruction. */
1395
1396 code_msb &= 0xef;
1397 bfd_put_8 (abfd, code_msb, contents + irel->r_offset + 1);
1398 if (DEBUG_RELAX)
1399 printf ("converted rcall/ret sequence at address 0x%x"
1400 " into rjmp/ret sequence. Section is %s\n\n",
1401 (int) dot, sec->name);
1402 *again = TRUE;
1403 break;
1404 }
1405 }
1406 else if ((0x94 == (code_msb & 0xfe))
1407 && (0x0e == (code_lsb & 0x0e)))
1408 {
1409 /* This insn is a call. */
1410 unsigned char next_insn_msb = 0;
1411 unsigned char next_insn_lsb = 0;
1412
1413 if (irel->r_offset + 5 < sec->size)
1414 {
1415 next_insn_msb =
1416 bfd_get_8 (abfd, contents + irel->r_offset + 5);
1417 next_insn_lsb =
1418 bfd_get_8 (abfd, contents + irel->r_offset + 4);
1419 }
1420 if ((0x95 == next_insn_msb) && (0x08 == next_insn_lsb))
1421 {
1422 /* The next insn is a ret. We now convert the call insn
1423 into a jmp instruction. */
1424
1425 code_lsb &= 0xfd;
1426 bfd_put_8 (abfd, code_lsb, contents + irel->r_offset);
1427 if (DEBUG_RELAX)
1428 printf ("converted call/ret sequence at address 0x%x"
1429 " into jmp/ret sequence. Section is %s\n\n",
1430 (int) dot, sec->name);
1431 *again = TRUE;
1432 break;
1433 }
1434 }
1435 else if ((0xc0 == (code_msb & 0xf0))
1436 || ((0x94 == (code_msb & 0xfe))
1437 && (0x0c == (code_lsb & 0x0e))))
1438 {
1439 /* this insn is a rjmp or a jmp. */
1440 unsigned char next_insn_msb = 0;
1441 unsigned char next_insn_lsb = 0;
1442 int insn_size;
1443
1444 if (0xc0 == (code_msb & 0xf0))
1445 insn_size = 2; /* rjmp insn */
1446 else
1447 insn_size = 4; /* jmp insn */
1448
1449 if (irel->r_offset + insn_size + 1 < sec->size)
1450 {
1451 next_insn_msb =
1452 bfd_get_8 (abfd, contents + irel->r_offset
1453 + insn_size + 1);
1454 next_insn_lsb =
1455 bfd_get_8 (abfd, contents + irel->r_offset
1456 + insn_size);
1457 }
1458
1459 if ((0x95 == next_insn_msb) && (0x08 == next_insn_lsb))
1460 {
1461 /* The next insn is a ret. We possibly could delete
1462 this ret. First we need to check for preceeding
1463 sbis/sbic/sbrs or cpse "skip" instructions. */
1464
1465 int there_is_preceeding_non_skip_insn = 1;
1466 bfd_vma address_of_ret;
1467
1468 address_of_ret = dot + insn_size;
1469
1470 if (DEBUG_RELAX && (insn_size == 2))
1471 printf ("found rjmp / ret sequence at "
1472 "address 0x%x\n",
1473 (int) dot);
1474 if (DEBUG_RELAX && (insn_size == 4))
1475 printf ("found jmp / ret sequence at "
1476 "address 0x%x\n",
1477 (int) dot);
1478
1479 /* We have to make sure that there is a preceeding insn. */
1480 if (irel->r_offset >= 2)
1481 {
1482 unsigned char preceeding_msb;
1483 unsigned char preceeding_lsb;
1484 preceeding_msb =
1485 bfd_get_8 (abfd, contents + irel->r_offset - 1);
1486 preceeding_lsb =
1487 bfd_get_8 (abfd, contents + irel->r_offset - 2);
1488
1489 /* sbic. */
1490 if (0x99 == preceeding_msb)
1491 there_is_preceeding_non_skip_insn = 0;
1492
1493 /* sbis. */
1494 if (0x9b == preceeding_msb)
1495 there_is_preceeding_non_skip_insn = 0;
1496
1497 /* sbrc */
1498 if ((0xfc == (preceeding_msb & 0xfe)
1499 && (0x00 == (preceeding_lsb & 0x08))))
1500 there_is_preceeding_non_skip_insn = 0;
1501
1502 /* sbrs */
1503 if ((0xfe == (preceeding_msb & 0xfe)
1504 && (0x00 == (preceeding_lsb & 0x08))))
1505 there_is_preceeding_non_skip_insn = 0;
1506
1507 /* cpse */
1508 if (0x10 == (preceeding_msb & 0xfc))
1509 there_is_preceeding_non_skip_insn = 0;
1510
1511 if (there_is_preceeding_non_skip_insn == 0)
1512 if (DEBUG_RELAX)
1513 printf ("preceeding skip insn prevents deletion of"
1514 " ret insn at addr 0x%x in section %s\n",
1515 (int) dot + 2, sec->name);
1516 }
1517 else
1518 {
1519 /* There is no previous instruction. */
1520 there_is_preceeding_non_skip_insn = 0;
1521 }
1522
1523 if (there_is_preceeding_non_skip_insn)
1524 {
1525 /* We now only have to make sure that there is no
1526 local label defined at the address of the ret
1527 instruction and that there is no local relocation
1528 in this section pointing to the ret. */
1529
1530 int deleting_ret_is_safe = 1;
1531 unsigned int section_offset_of_ret_insn =
1532 irel->r_offset + insn_size;
1533 Elf_Internal_Sym *isym, *isymend;
1534 unsigned int sec_shndx;
1535
1536 sec_shndx =
1537 _bfd_elf_section_from_bfd_section (abfd, sec);
1538
1539 /* Check for local symbols. */
1540 isym = (Elf_Internal_Sym *) symtab_hdr->contents;
1541 isymend = isym + symtab_hdr->sh_info;
1542 for (; isym < isymend; isym++)
1543 {
1544 if (isym->st_value == section_offset_of_ret_insn
1545 && isym->st_shndx == sec_shndx)
1546 {
1547 deleting_ret_is_safe = 0;
1548 if (DEBUG_RELAX)
1549 printf ("local label prevents deletion of ret "
1550 "insn at address 0x%x\n",
1551 (int) dot + insn_size);
1552 }
1553 }
1554
1555 /* Now check for global symbols. */
1556 {
1557 int symcount;
1558 struct elf_link_hash_entry **sym_hashes;
1559 struct elf_link_hash_entry **end_hashes;
1560
1561 symcount = (symtab_hdr->sh_size
1562 / sizeof (Elf32_External_Sym)
1563 - symtab_hdr->sh_info);
1564 sym_hashes = elf_sym_hashes (abfd);
1565 end_hashes = sym_hashes + symcount;
1566 for (; sym_hashes < end_hashes; sym_hashes++)
1567 {
1568 struct elf_link_hash_entry *sym_hash =
1569 *sym_hashes;
1570 if ((sym_hash->root.type == bfd_link_hash_defined
1571 || sym_hash->root.type ==
1572 bfd_link_hash_defweak)
1573 && sym_hash->root.u.def.section == sec
1574 && sym_hash->root.u.def.value ==
1575 section_offset_of_ret_insn)
1576 {
1577 deleting_ret_is_safe = 0;
1578 if (DEBUG_RELAX)
1579 printf ("global label prevents deletion of "
1580 "ret insn at address 0x%x\n",
1581 (int) dot + insn_size);
1582 }
1583 }
1584 }
1585 /* Now we check for relocations pointing to ret. */
1586 {
1587 Elf_Internal_Rela *irel;
1588 Elf_Internal_Rela *relend;
1589 Elf_Internal_Shdr *symtab_hdr;
1590
1591 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1592 relend = elf_section_data (sec)->relocs
1593 + sec->reloc_count;
1594
1595 for (irel = elf_section_data (sec)->relocs;
1596 irel < relend; irel++)
1597 {
1598 bfd_vma reloc_target = 0;
1599 bfd_vma symval;
1600 Elf_Internal_Sym *isymbuf = NULL;
1601
1602 /* Read this BFD's local symbols if we haven't
1603 done so already. */
1604 if (isymbuf == NULL && symtab_hdr->sh_info != 0)
1605 {
1606 isymbuf = (Elf_Internal_Sym *)
1607 symtab_hdr->contents;
1608 if (isymbuf == NULL)
1609 isymbuf = bfd_elf_get_elf_syms (
1610 abfd,
1611 symtab_hdr,
1612 symtab_hdr->sh_info, 0,
1613 NULL, NULL, NULL);
1614 if (isymbuf == NULL)
1615 break;
1616 }
1617
1618 /* Get the value of the symbol referred to
1619 by the reloc. */
1620 if (ELF32_R_SYM (irel->r_info)
1621 < symtab_hdr->sh_info)
1622 {
1623 /* A local symbol. */
1624 Elf_Internal_Sym *isym;
1625 asection *sym_sec;
1626
1627 isym = isymbuf
1628 + ELF32_R_SYM (irel->r_info);
1629 sym_sec = bfd_section_from_elf_index (
1630 abfd, isym->st_shndx);
1631 symval = isym->st_value;
1632
1633 /* If the reloc is absolute, it will not
1634 have a symbol or section associated
1635 with it. */
1636
1637 if (sym_sec)
1638 {
1639 symval +=
1640 sym_sec->output_section->vma
1641 + sym_sec->output_offset;
1642 reloc_target = symval + irel->r_addend;
1643 }
1644 else
1645 {
1646 reloc_target = symval + irel->r_addend;
1647 /* reference symbol is absolute. */
1648 }
1649 }
1650 else
1651 {
1652 /* reference symbol is extern. */
1653 }
1654
1655 if (address_of_ret == reloc_target)
1656 {
1657 deleting_ret_is_safe = 0;
1658 if (DEBUG_RELAX)
1659 printf ("ret from "
1660 "rjmp/jmp ret sequence at address"
1661 " 0x%x could not be deleted. ret"
1662 " is target of a relocation.\n",
1663 (int) address_of_ret);
1664 }
1665 }
1666 }
1667
1668 if (deleting_ret_is_safe)
1669 {
1670 if (DEBUG_RELAX)
1671 printf ("unreachable ret instruction "
1672 "at address 0x%x deleted.\n",
1673 (int) dot + insn_size);
1674
1675 /* Delete two bytes of data. */
1676 if (!elf32_avr_relax_delete_bytes (abfd, sec,
1677 irel->r_offset + insn_size, 2))
1678 goto error_return;
1679
1680 /* That will change things, so, we should relax
1681 again. Note that this is not required, and it
1682 may be slow. */
1683
1684 *again = TRUE;
1685 break;
1686 }
1687 }
1688
1689 }
1690 }
1691 break;
1692 }
1693 }
1694 }
1695
1696 if (contents != NULL
1697 && elf_section_data (sec)->this_hdr.contents != contents)
1698 {
1699 if (! link_info->keep_memory)
1700 free (contents);
1701 else
1702 {
1703 /* Cache the section contents for elf_link_input_bfd. */
1704 elf_section_data (sec)->this_hdr.contents = contents;
1705 }
1706 }
1707
1708 if (internal_relocs != NULL
1709 && elf_section_data (sec)->relocs != internal_relocs)
1710 free (internal_relocs);
1711
1712 return TRUE;
1713
1714 error_return:
1715 if (isymbuf != NULL
1716 && symtab_hdr->contents != (unsigned char *) isymbuf)
1717 free (isymbuf);
1718 if (contents != NULL
1719 && elf_section_data (sec)->this_hdr.contents != contents)
1720 free (contents);
1721 if (internal_relocs != NULL
1722 && elf_section_data (sec)->relocs != internal_relocs)
1723 free (internal_relocs);
1724
1725 return FALSE;
1726 }
1727
1728 /* Delete some bytes from a section while changing the size of an instruction.
1729 The parameter "addr" denotes the section-relative offset pointing just
1730 behind the shrinked instruction. "addr+count" point at the first
1731 byte just behind the original unshrinked instruction. */
1732 static bfd_boolean
1733 elf32_avr_relax_delete_bytes (bfd *abfd, asection *sec,
1734 bfd_vma addr, int count)
1735 {
1736 Elf_Internal_Shdr *symtab_hdr;
1737 unsigned int sec_shndx;
1738 bfd_byte *contents;
1739 Elf_Internal_Rela *irel, *irelend;
1740 Elf_Internal_Rela *irelalign;
1741 Elf_Internal_Sym *isym;
1742 Elf_Internal_Sym *isymbuf = NULL;
1743 Elf_Internal_Sym *isymend;
1744 bfd_vma toaddr;
1745 struct elf_link_hash_entry **sym_hashes;
1746 struct elf_link_hash_entry **end_hashes;
1747 unsigned int symcount;
1748
1749 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1750 sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
1751 contents = elf_section_data (sec)->this_hdr.contents;
1752
1753 /* The deletion must stop at the next ALIGN reloc for an aligment
1754 power larger than the number of bytes we are deleting. */
1755
1756 irelalign = NULL;
1757 toaddr = sec->size;
1758
1759 irel = elf_section_data (sec)->relocs;
1760 irelend = irel + sec->reloc_count;
1761
1762 /* Actually delete the bytes. */
1763 if (toaddr - addr - count > 0)
1764 memmove (contents + addr, contents + addr + count,
1765 (size_t) (toaddr - addr - count));
1766 sec->size -= count;
1767
1768 /* Adjust all the relocs. */
1769 for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
1770 {
1771 bfd_vma symval;
1772 bfd_vma old_reloc_address;
1773 bfd_vma shrinked_insn_address;
1774
1775 old_reloc_address = (sec->output_section->vma
1776 + sec->output_offset + irel->r_offset);
1777 shrinked_insn_address = (sec->output_section->vma
1778 + sec->output_offset + addr - count);
1779
1780 /* Get the new reloc address. */
1781 if ((irel->r_offset > addr
1782 && irel->r_offset < toaddr))
1783 {
1784 if (DEBUG_RELAX)
1785 printf ("Relocation at address 0x%x needs to be moved.\n"
1786 "Old section offset: 0x%x, New section offset: 0x%x \n",
1787 (unsigned int) old_reloc_address,
1788 (unsigned int) irel->r_offset,
1789 (unsigned int) ((irel->r_offset) - count));
1790
1791 irel->r_offset -= count;
1792 }
1793
1794 /* The reloc's own addresses are now ok. However, we need to readjust
1795 the reloc's addend if two conditions are met:
1796 1.) the reloc is relative to a symbol in this section that
1797 is located in front of the shrinked instruction
1798 2.) symbol plus addend end up behind the shrinked instruction.
1799
1800 This should happen only for local symbols that are progmem related. */
1801
1802 /* Read this BFD's local symbols if we haven't done so already. */
1803 if (isymbuf == NULL && symtab_hdr->sh_info != 0)
1804 {
1805 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
1806 if (isymbuf == NULL)
1807 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
1808 symtab_hdr->sh_info, 0,
1809 NULL, NULL, NULL);
1810 if (isymbuf == NULL)
1811 return FALSE;
1812 }
1813
1814 /* Get the value of the symbol referred to by the reloc. */
1815 if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
1816 {
1817 /* A local symbol. */
1818 Elf_Internal_Sym *isym;
1819 asection *sym_sec;
1820
1821 isym = isymbuf + ELF32_R_SYM (irel->r_info);
1822 sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
1823 symval = isym->st_value;
1824 /* If the reloc is absolute, it will not have
1825 a symbol or section associated with it. */
1826 if (sym_sec)
1827 {
1828 symval += sym_sec->output_section->vma
1829 + sym_sec->output_offset;
1830
1831 if (DEBUG_RELAX)
1832 printf ("Checking if the relocation's "
1833 "addend needs corrections.\n"
1834 "Address of anchor symbol: 0x%x \n"
1835 "Address of relocation target: 0x%x \n"
1836 "Address of relaxed insn: 0x%x \n",
1837 (unsigned int) symval,
1838 (unsigned int) (symval + irel->r_addend),
1839 (unsigned int) shrinked_insn_address);
1840
1841 if ( symval <= shrinked_insn_address
1842 && (symval + irel->r_addend) > shrinked_insn_address)
1843 {
1844 irel->r_addend -= count;
1845
1846 if (DEBUG_RELAX)
1847 printf ("Anchor symbol and relocation target bracket "
1848 "shrinked insn address.\n"
1849 "Need for new addend : 0x%x\n",
1850 (unsigned int) irel->r_addend);
1851 }
1852 }
1853 else
1854 {
1855 /* Reference symbol is absolute. No adjustment needed. */
1856 }
1857 }
1858 else
1859 {
1860 /* Reference symbol is extern. No need for adjusting the addend. */
1861 }
1862 }
1863
1864 /* Adjust the local symbols defined in this section. */
1865 isym = (Elf_Internal_Sym *) symtab_hdr->contents;
1866 isymend = isym + symtab_hdr->sh_info;
1867 for (; isym < isymend; isym++)
1868 {
1869 if (isym->st_shndx == sec_shndx
1870 && isym->st_value > addr
1871 && isym->st_value < toaddr)
1872 isym->st_value -= count;
1873 }
1874
1875 /* Now adjust the global symbols defined in this section. */
1876 symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
1877 - symtab_hdr->sh_info);
1878 sym_hashes = elf_sym_hashes (abfd);
1879 end_hashes = sym_hashes + symcount;
1880 for (; sym_hashes < end_hashes; sym_hashes++)
1881 {
1882 struct elf_link_hash_entry *sym_hash = *sym_hashes;
1883 if ((sym_hash->root.type == bfd_link_hash_defined
1884 || sym_hash->root.type == bfd_link_hash_defweak)
1885 && sym_hash->root.u.def.section == sec
1886 && sym_hash->root.u.def.value > addr
1887 && sym_hash->root.u.def.value < toaddr)
1888 {
1889 sym_hash->root.u.def.value -= count;
1890 }
1891 }
1892
1893 return TRUE;
1894 }
1895
1896 /* This is a version of bfd_generic_get_relocated_section_contents
1897 which uses elf32_avr_relocate_section.
1898
1899 For avr it's essentially a cut and paste taken from the H8300 port.
1900 The author of the relaxation support patch for avr had absolutely no
1901 clue what is happening here but found out that this part of the code
1902 seems to be important. */
1903
1904 static bfd_byte *
1905 elf32_avr_get_relocated_section_contents (bfd *output_bfd,
1906 struct bfd_link_info *link_info,
1907 struct bfd_link_order *link_order,
1908 bfd_byte *data,
1909 bfd_boolean relocatable,
1910 asymbol **symbols)
1911 {
1912 Elf_Internal_Shdr *symtab_hdr;
1913 asection *input_section = link_order->u.indirect.section;
1914 bfd *input_bfd = input_section->owner;
1915 asection **sections = NULL;
1916 Elf_Internal_Rela *internal_relocs = NULL;
1917 Elf_Internal_Sym *isymbuf = NULL;
1918
1919 /* We only need to handle the case of relaxing, or of having a
1920 particular set of section contents, specially. */
1921 if (relocatable
1922 || elf_section_data (input_section)->this_hdr.contents == NULL)
1923 return bfd_generic_get_relocated_section_contents (output_bfd, link_info,
1924 link_order, data,
1925 relocatable,
1926 symbols);
1927 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
1928
1929 memcpy (data, elf_section_data (input_section)->this_hdr.contents,
1930 (size_t) input_section->size);
1931
1932 if ((input_section->flags & SEC_RELOC) != 0
1933 && input_section->reloc_count > 0)
1934 {
1935 asection **secpp;
1936 Elf_Internal_Sym *isym, *isymend;
1937 bfd_size_type amt;
1938
1939 internal_relocs = (_bfd_elf_link_read_relocs
1940 (input_bfd, input_section, (PTR) NULL,
1941 (Elf_Internal_Rela *) NULL, FALSE));
1942 if (internal_relocs == NULL)
1943 goto error_return;
1944
1945 if (symtab_hdr->sh_info != 0)
1946 {
1947 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
1948 if (isymbuf == NULL)
1949 isymbuf = bfd_elf_get_elf_syms (input_bfd, symtab_hdr,
1950 symtab_hdr->sh_info, 0,
1951 NULL, NULL, NULL);
1952 if (isymbuf == NULL)
1953 goto error_return;
1954 }
1955
1956 amt = symtab_hdr->sh_info;
1957 amt *= sizeof (asection *);
1958 sections = (asection **) bfd_malloc (amt);
1959 if (sections == NULL && amt != 0)
1960 goto error_return;
1961
1962 isymend = isymbuf + symtab_hdr->sh_info;
1963 for (isym = isymbuf, secpp = sections; isym < isymend; ++isym, ++secpp)
1964 {
1965 asection *isec;
1966
1967 if (isym->st_shndx == SHN_UNDEF)
1968 isec = bfd_und_section_ptr;
1969 else if (isym->st_shndx == SHN_ABS)
1970 isec = bfd_abs_section_ptr;
1971 else if (isym->st_shndx == SHN_COMMON)
1972 isec = bfd_com_section_ptr;
1973 else
1974 isec = bfd_section_from_elf_index (input_bfd, isym->st_shndx);
1975
1976 *secpp = isec;
1977 }
1978
1979 if (! elf32_avr_relocate_section (output_bfd, link_info, input_bfd,
1980 input_section, data, internal_relocs,
1981 isymbuf, sections))
1982 goto error_return;
1983
1984 if (sections != NULL)
1985 free (sections);
1986 if (isymbuf != NULL
1987 && symtab_hdr->contents != (unsigned char *) isymbuf)
1988 free (isymbuf);
1989 if (elf_section_data (input_section)->relocs != internal_relocs)
1990 free (internal_relocs);
1991 }
1992
1993 return data;
1994
1995 error_return:
1996 if (sections != NULL)
1997 free (sections);
1998 if (isymbuf != NULL
1999 && symtab_hdr->contents != (unsigned char *) isymbuf)
2000 free (isymbuf);
2001 if (internal_relocs != NULL
2002 && elf_section_data (input_section)->relocs != internal_relocs)
2003 free (internal_relocs);
2004 return NULL;
2005 }
2006
2007
2008 #define ELF_ARCH bfd_arch_avr
2009 #define ELF_MACHINE_CODE EM_AVR
2010 #define ELF_MACHINE_ALT1 EM_AVR_OLD
2011 #define ELF_MAXPAGESIZE 1
2012
2013 #define TARGET_LITTLE_SYM bfd_elf32_avr_vec
2014 #define TARGET_LITTLE_NAME "elf32-avr"
2015
2016 #define elf_info_to_howto avr_info_to_howto_rela
2017 #define elf_info_to_howto_rel NULL
2018 #define elf_backend_relocate_section elf32_avr_relocate_section
2019 #define elf_backend_gc_mark_hook elf32_avr_gc_mark_hook
2020 #define elf_backend_gc_sweep_hook elf32_avr_gc_sweep_hook
2021 #define elf_backend_check_relocs elf32_avr_check_relocs
2022 #define elf_backend_can_gc_sections 1
2023 #define elf_backend_rela_normal 1
2024 #define elf_backend_final_write_processing \
2025 bfd_elf_avr_final_write_processing
2026 #define elf_backend_object_p elf32_avr_object_p
2027
2028 #define bfd_elf32_bfd_relax_section elf32_avr_relax_section
2029 #define bfd_elf32_bfd_get_relocated_section_contents \
2030 elf32_avr_get_relocated_section_contents
2031
2032 #include "elf32-target.h"
GDB Binutils - Deliverables
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