* elflink.c (_bfd_elf_gc_mark_hook): New function.
[deliverable/binutils-gdb.git] / bfd / elf32-m68hc12.c
1 /* Motorola 68HC12-specific support for 32-bit ELF
2 Copyright 1999, 2000, 2002, 2003, 2004, 2005, 2006
3 Free Software Foundation, Inc.
4 Contributed by Stephane Carrez (stcarrez@nerim.fr)
5 (Heavily copied from the D10V port by Martin Hunt (hunt@cygnus.com))
6
7 This file is part of BFD, the Binary File Descriptor library.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
22
23 #include "bfd.h"
24 #include "sysdep.h"
25 #include "bfdlink.h"
26 #include "libbfd.h"
27 #include "elf-bfd.h"
28 #include "elf32-m68hc1x.h"
29 #include "elf/m68hc11.h"
30 #include "opcode/m68hc11.h"
31
32 /* Relocation functions. */
33 static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
34 (bfd *, bfd_reloc_code_real_type);
35 static void m68hc11_info_to_howto_rel
36 (bfd *, arelent *, Elf_Internal_Rela *);
37
38 /* Trampoline generation. */
39 static bfd_boolean m68hc12_elf_size_one_stub
40 (struct bfd_hash_entry *gen_entry, void *in_arg);
41 static bfd_boolean m68hc12_elf_build_one_stub
42 (struct bfd_hash_entry *gen_entry, void *in_arg);
43 static struct bfd_link_hash_table* m68hc12_elf_bfd_link_hash_table_create
44 (bfd*);
45
46 static bfd_boolean m68hc12_elf_set_mach_from_flags PARAMS ((bfd *));
47
48 /* Use REL instead of RELA to save space */
49 #define USE_REL 1
50
51 /* The 68HC12 microcontroler has a memory bank switching system
52 with a 16Kb window in the 64Kb address space. The extended memory
53 is mapped in the 16Kb window (at 0x8000). The page register controls
54 which 16Kb bank is mapped. The call/rtc instructions take care of
55 bank switching in function calls/returns.
56
57 For GNU Binutils to work, we consider there is a physical memory
58 at 0..0x0ffff and a kind of virtual memory above that. Symbols
59 in virtual memory have their addresses treated in a special way
60 when disassembling and when linking.
61
62 For the linker to work properly, we must always relocate the virtual
63 memory as if it is mapped at 0x8000. When a 16-bit relocation is
64 made in the virtual memory, we check that it does not cross the
65 memory bank where it is used. This would involve a page change
66 which would be wrong. The 24-bit relocation is for that and it
67 treats the address as a physical address + page number.
68
69
70 Banked
71 Address Space
72 | | Page n
73 +---------------+ 0x1010000
74 | |
75 | jsr _foo |
76 | .. | Page 3
77 | _foo: |
78 +---------------+ 0x100C000
79 | |
80 | call _bar |
81 | .. | Page 2
82 | _bar: |
83 +---------------+ 0x1008000
84 /------>| |
85 | | call _foo | Page 1
86 | | |
87 | +---------------+ 0x1004000
88 Physical | | |
89 Address Space | | | Page 0
90 | | |
91 +-----------+ 0x00FFFF | +---------------+ 0x1000000
92 | | |
93 | call _foo | |
94 | | |
95 +-----------+ 0x00BFFF -+---/
96 | | |
97 | | |
98 | | 16K |
99 | | |
100 +-----------+ 0x008000 -+
101 | |
102 | |
103 = =
104 | |
105 | |
106 +-----------+ 0000
107
108
109 The 'call _foo' must be relocated with page 3 and 16-bit address
110 mapped at 0x8000.
111
112 The 3-bit and 16-bit PC rel relocation is only used by 68HC12. */
113 static reloc_howto_type elf_m68hc11_howto_table[] = {
114 /* This reloc does nothing. */
115 HOWTO (R_M68HC11_NONE, /* type */
116 0, /* rightshift */
117 2, /* size (0 = byte, 1 = short, 2 = long) */
118 32, /* bitsize */
119 FALSE, /* pc_relative */
120 0, /* bitpos */
121 complain_overflow_dont,/* complain_on_overflow */
122 bfd_elf_generic_reloc, /* special_function */
123 "R_M68HC12_NONE", /* name */
124 FALSE, /* partial_inplace */
125 0, /* src_mask */
126 0, /* dst_mask */
127 FALSE), /* pcrel_offset */
128
129 /* A 8 bit absolute relocation */
130 HOWTO (R_M68HC11_8, /* type */
131 0, /* rightshift */
132 0, /* size (0 = byte, 1 = short, 2 = long) */
133 8, /* bitsize */
134 FALSE, /* pc_relative */
135 0, /* bitpos */
136 complain_overflow_bitfield, /* complain_on_overflow */
137 bfd_elf_generic_reloc, /* special_function */
138 "R_M68HC12_8", /* name */
139 FALSE, /* partial_inplace */
140 0x00ff, /* src_mask */
141 0x00ff, /* dst_mask */
142 FALSE), /* pcrel_offset */
143
144 /* A 8 bit absolute relocation (upper address) */
145 HOWTO (R_M68HC11_HI8, /* type */
146 8, /* rightshift */
147 0, /* size (0 = byte, 1 = short, 2 = long) */
148 8, /* bitsize */
149 FALSE, /* pc_relative */
150 0, /* bitpos */
151 complain_overflow_bitfield, /* complain_on_overflow */
152 bfd_elf_generic_reloc, /* special_function */
153 "R_M68HC12_HI8", /* name */
154 FALSE, /* partial_inplace */
155 0x00ff, /* src_mask */
156 0x00ff, /* dst_mask */
157 FALSE), /* pcrel_offset */
158
159 /* A 8 bit absolute relocation (upper address) */
160 HOWTO (R_M68HC11_LO8, /* type */
161 0, /* rightshift */
162 0, /* size (0 = byte, 1 = short, 2 = long) */
163 8, /* bitsize */
164 FALSE, /* pc_relative */
165 0, /* bitpos */
166 complain_overflow_dont, /* complain_on_overflow */
167 bfd_elf_generic_reloc, /* special_function */
168 "R_M68HC12_LO8", /* name */
169 FALSE, /* partial_inplace */
170 0x00ff, /* src_mask */
171 0x00ff, /* dst_mask */
172 FALSE), /* pcrel_offset */
173
174 /* A 8 bit PC-rel relocation */
175 HOWTO (R_M68HC11_PCREL_8, /* type */
176 0, /* rightshift */
177 0, /* size (0 = byte, 1 = short, 2 = long) */
178 8, /* bitsize */
179 TRUE, /* pc_relative */
180 0, /* bitpos */
181 complain_overflow_bitfield, /* complain_on_overflow */
182 bfd_elf_generic_reloc, /* special_function */
183 "R_M68HC12_PCREL_8", /* name */
184 FALSE, /* partial_inplace */
185 0x00ff, /* src_mask */
186 0x00ff, /* dst_mask */
187 TRUE), /* pcrel_offset */
188
189 /* A 16 bit absolute relocation */
190 HOWTO (R_M68HC11_16, /* type */
191 0, /* rightshift */
192 1, /* size (0 = byte, 1 = short, 2 = long) */
193 16, /* bitsize */
194 FALSE, /* pc_relative */
195 0, /* bitpos */
196 complain_overflow_dont /*bitfield */ , /* complain_on_overflow */
197 bfd_elf_generic_reloc, /* special_function */
198 "R_M68HC12_16", /* name */
199 FALSE, /* partial_inplace */
200 0xffff, /* src_mask */
201 0xffff, /* dst_mask */
202 FALSE), /* pcrel_offset */
203
204 /* A 32 bit absolute relocation. This one is never used for the
205 code relocation. It's used by gas for -gstabs generation. */
206 HOWTO (R_M68HC11_32, /* type */
207 0, /* rightshift */
208 2, /* size (0 = byte, 1 = short, 2 = long) */
209 32, /* bitsize */
210 FALSE, /* pc_relative */
211 0, /* bitpos */
212 complain_overflow_bitfield, /* complain_on_overflow */
213 bfd_elf_generic_reloc, /* special_function */
214 "R_M68HC12_32", /* name */
215 FALSE, /* partial_inplace */
216 0xffffffff, /* src_mask */
217 0xffffffff, /* dst_mask */
218 FALSE), /* pcrel_offset */
219
220 /* A 3 bit absolute relocation */
221 HOWTO (R_M68HC11_3B, /* type */
222 0, /* rightshift */
223 0, /* size (0 = byte, 1 = short, 2 = long) */
224 3, /* bitsize */
225 FALSE, /* pc_relative */
226 0, /* bitpos */
227 complain_overflow_bitfield, /* complain_on_overflow */
228 bfd_elf_generic_reloc, /* special_function */
229 "R_M68HC12_4B", /* name */
230 FALSE, /* partial_inplace */
231 0x003, /* src_mask */
232 0x003, /* dst_mask */
233 FALSE), /* pcrel_offset */
234
235 /* A 16 bit PC-rel relocation */
236 HOWTO (R_M68HC11_PCREL_16, /* type */
237 0, /* rightshift */
238 1, /* size (0 = byte, 1 = short, 2 = long) */
239 16, /* bitsize */
240 TRUE, /* pc_relative */
241 0, /* bitpos */
242 complain_overflow_dont, /* complain_on_overflow */
243 bfd_elf_generic_reloc, /* special_function */
244 "R_M68HC12_PCREL_16", /* name */
245 FALSE, /* partial_inplace */
246 0xffff, /* src_mask */
247 0xffff, /* dst_mask */
248 TRUE), /* pcrel_offset */
249
250 /* GNU extension to record C++ vtable hierarchy */
251 HOWTO (R_M68HC11_GNU_VTINHERIT, /* type */
252 0, /* rightshift */
253 1, /* size (0 = byte, 1 = short, 2 = long) */
254 0, /* bitsize */
255 FALSE, /* pc_relative */
256 0, /* bitpos */
257 complain_overflow_dont, /* complain_on_overflow */
258 NULL, /* special_function */
259 "R_M68HC11_GNU_VTINHERIT", /* name */
260 FALSE, /* partial_inplace */
261 0, /* src_mask */
262 0, /* dst_mask */
263 FALSE), /* pcrel_offset */
264
265 /* GNU extension to record C++ vtable member usage */
266 HOWTO (R_M68HC11_GNU_VTENTRY, /* type */
267 0, /* rightshift */
268 1, /* size (0 = byte, 1 = short, 2 = long) */
269 0, /* bitsize */
270 FALSE, /* pc_relative */
271 0, /* bitpos */
272 complain_overflow_dont, /* complain_on_overflow */
273 _bfd_elf_rel_vtable_reloc_fn, /* special_function */
274 "R_M68HC11_GNU_VTENTRY", /* name */
275 FALSE, /* partial_inplace */
276 0, /* src_mask */
277 0, /* dst_mask */
278 FALSE), /* pcrel_offset */
279
280 /* A 24 bit relocation */
281 HOWTO (R_M68HC11_24, /* type */
282 0, /* rightshift */
283 2, /* size (0 = byte, 1 = short, 2 = long) */
284 24, /* bitsize */
285 FALSE, /* pc_relative */
286 0, /* bitpos */
287 complain_overflow_dont, /* complain_on_overflow */
288 m68hc11_elf_special_reloc, /* special_function */
289 "R_M68HC12_24", /* name */
290 FALSE, /* partial_inplace */
291 0xffffff, /* src_mask */
292 0xffffff, /* dst_mask */
293 FALSE), /* pcrel_offset */
294
295 /* A 16-bit low relocation */
296 HOWTO (R_M68HC11_LO16, /* type */
297 0, /* rightshift */
298 1, /* size (0 = byte, 1 = short, 2 = long) */
299 16, /* bitsize */
300 FALSE, /* pc_relative */
301 0, /* bitpos */
302 complain_overflow_dont, /* complain_on_overflow */
303 m68hc11_elf_special_reloc,/* special_function */
304 "R_M68HC12_LO16", /* name */
305 FALSE, /* partial_inplace */
306 0xffff, /* src_mask */
307 0xffff, /* dst_mask */
308 FALSE), /* pcrel_offset */
309
310 /* A page relocation */
311 HOWTO (R_M68HC11_PAGE, /* type */
312 0, /* rightshift */
313 0, /* size (0 = byte, 1 = short, 2 = long) */
314 8, /* bitsize */
315 FALSE, /* pc_relative */
316 0, /* bitpos */
317 complain_overflow_dont, /* complain_on_overflow */
318 m68hc11_elf_special_reloc,/* special_function */
319 "R_M68HC12_PAGE", /* name */
320 FALSE, /* partial_inplace */
321 0x00ff, /* src_mask */
322 0x00ff, /* dst_mask */
323 FALSE), /* pcrel_offset */
324
325 EMPTY_HOWTO (14),
326 EMPTY_HOWTO (15),
327 EMPTY_HOWTO (16),
328 EMPTY_HOWTO (17),
329 EMPTY_HOWTO (18),
330 EMPTY_HOWTO (19),
331
332 /* Mark beginning of a jump instruction (any form). */
333 HOWTO (R_M68HC11_RL_JUMP, /* type */
334 0, /* rightshift */
335 1, /* size (0 = byte, 1 = short, 2 = long) */
336 0, /* bitsize */
337 FALSE, /* pc_relative */
338 0, /* bitpos */
339 complain_overflow_dont, /* complain_on_overflow */
340 m68hc11_elf_ignore_reloc, /* special_function */
341 "R_M68HC12_RL_JUMP", /* name */
342 TRUE, /* partial_inplace */
343 0, /* src_mask */
344 0, /* dst_mask */
345 TRUE), /* pcrel_offset */
346
347 /* Mark beginning of Gcc relaxation group instruction. */
348 HOWTO (R_M68HC11_RL_GROUP, /* type */
349 0, /* rightshift */
350 1, /* size (0 = byte, 1 = short, 2 = long) */
351 0, /* bitsize */
352 FALSE, /* pc_relative */
353 0, /* bitpos */
354 complain_overflow_dont, /* complain_on_overflow */
355 m68hc11_elf_ignore_reloc, /* special_function */
356 "R_M68HC12_RL_GROUP", /* name */
357 TRUE, /* partial_inplace */
358 0, /* src_mask */
359 0, /* dst_mask */
360 TRUE), /* pcrel_offset */
361 };
362
363 /* Map BFD reloc types to M68HC11 ELF reloc types. */
364
365 struct m68hc11_reloc_map
366 {
367 bfd_reloc_code_real_type bfd_reloc_val;
368 unsigned char elf_reloc_val;
369 };
370
371 static const struct m68hc11_reloc_map m68hc11_reloc_map[] = {
372 {BFD_RELOC_NONE, R_M68HC11_NONE,},
373 {BFD_RELOC_8, R_M68HC11_8},
374 {BFD_RELOC_M68HC11_HI8, R_M68HC11_HI8},
375 {BFD_RELOC_M68HC11_LO8, R_M68HC11_LO8},
376 {BFD_RELOC_8_PCREL, R_M68HC11_PCREL_8},
377 {BFD_RELOC_16_PCREL, R_M68HC11_PCREL_16},
378 {BFD_RELOC_16, R_M68HC11_16},
379 {BFD_RELOC_32, R_M68HC11_32},
380 {BFD_RELOC_M68HC11_3B, R_M68HC11_3B},
381
382 {BFD_RELOC_VTABLE_INHERIT, R_M68HC11_GNU_VTINHERIT},
383 {BFD_RELOC_VTABLE_ENTRY, R_M68HC11_GNU_VTENTRY},
384
385 {BFD_RELOC_M68HC11_LO16, R_M68HC11_LO16},
386 {BFD_RELOC_M68HC11_PAGE, R_M68HC11_PAGE},
387 {BFD_RELOC_M68HC11_24, R_M68HC11_24},
388
389 {BFD_RELOC_M68HC11_RL_JUMP, R_M68HC11_RL_JUMP},
390 {BFD_RELOC_M68HC11_RL_GROUP, R_M68HC11_RL_GROUP},
391 };
392
393 static reloc_howto_type *
394 bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
395 bfd_reloc_code_real_type code)
396 {
397 unsigned int i;
398
399 for (i = 0;
400 i < sizeof (m68hc11_reloc_map) / sizeof (struct m68hc11_reloc_map);
401 i++)
402 {
403 if (m68hc11_reloc_map[i].bfd_reloc_val == code)
404 return &elf_m68hc11_howto_table[m68hc11_reloc_map[i].elf_reloc_val];
405 }
406
407 return NULL;
408 }
409
410 /* Set the howto pointer for an M68HC11 ELF reloc. */
411
412 static void
413 m68hc11_info_to_howto_rel (bfd *abfd ATTRIBUTE_UNUSED,
414 arelent *cache_ptr, Elf_Internal_Rela *dst)
415 {
416 unsigned int r_type;
417
418 r_type = ELF32_R_TYPE (dst->r_info);
419 BFD_ASSERT (r_type < (unsigned int) R_M68HC11_max);
420 cache_ptr->howto = &elf_m68hc11_howto_table[r_type];
421 }
422
423 \f
424 /* Far trampoline generation. */
425
426 /* Build a 68HC12 trampoline stub. */
427 static bfd_boolean
428 m68hc12_elf_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
429 {
430 struct elf32_m68hc11_stub_hash_entry *stub_entry;
431 struct bfd_link_info *info;
432 struct m68hc11_elf_link_hash_table *htab;
433 asection *stub_sec;
434 bfd *stub_bfd;
435 bfd_byte *loc;
436 bfd_vma sym_value, phys_page, phys_addr;
437
438 /* Massage our args to the form they really have. */
439 stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
440 info = (struct bfd_link_info *) in_arg;
441
442 htab = m68hc11_elf_hash_table (info);
443
444 stub_sec = stub_entry->stub_sec;
445
446 /* Make a note of the offset within the stubs for this entry. */
447 stub_entry->stub_offset = stub_sec->size;
448 stub_sec->size += 7;
449 loc = stub_sec->contents + stub_entry->stub_offset;
450
451 stub_bfd = stub_sec->owner;
452
453 /* Create the trampoline call stub:
454
455 ldy #%addr(symbol)
456 call %page(symbol), __trampoline
457
458 */
459 sym_value = (stub_entry->target_value
460 + stub_entry->target_section->output_offset
461 + stub_entry->target_section->output_section->vma);
462 phys_addr = m68hc11_phys_addr (&htab->pinfo, sym_value);
463 phys_page = m68hc11_phys_page (&htab->pinfo, sym_value);
464
465 /* ldy #%page(sym) */
466 bfd_put_8 (stub_bfd, 0xCD, loc);
467 bfd_put_16 (stub_bfd, phys_addr, loc + 1);
468 loc += 3;
469
470 /* call %page(sym), __trampoline */
471 bfd_put_8 (stub_bfd, 0x4a, loc);
472 bfd_put_16 (stub_bfd, htab->pinfo.trampoline_addr, loc + 1);
473 bfd_put_8 (stub_bfd, phys_page, loc + 3);
474
475 return TRUE;
476 }
477
478 /* As above, but don't actually build the stub. Just bump offset so
479 we know stub section sizes. */
480
481 static bfd_boolean
482 m68hc12_elf_size_one_stub (struct bfd_hash_entry *gen_entry,
483 void *in_arg ATTRIBUTE_UNUSED)
484 {
485 struct elf32_m68hc11_stub_hash_entry *stub_entry;
486
487 /* Massage our args to the form they really have. */
488 stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
489
490 stub_entry->stub_sec->size += 7;
491 return TRUE;
492 }
493
494 /* Create a 68HC12 ELF linker hash table. */
495
496 static struct bfd_link_hash_table *
497 m68hc12_elf_bfd_link_hash_table_create (bfd *abfd)
498 {
499 struct m68hc11_elf_link_hash_table *ret;
500
501 ret = m68hc11_elf_hash_table_create (abfd);
502 if (ret == (struct m68hc11_elf_link_hash_table *) NULL)
503 return NULL;
504
505 ret->size_one_stub = m68hc12_elf_size_one_stub;
506 ret->build_one_stub = m68hc12_elf_build_one_stub;
507
508 return &ret->root.root;
509 }
510 \f
511 static bfd_boolean
512 m68hc12_elf_set_mach_from_flags (bfd *abfd)
513 {
514 flagword flags = elf_elfheader (abfd)->e_flags;
515
516 switch (flags & EF_M68HC11_MACH_MASK)
517 {
518 case EF_M68HC12_MACH:
519 bfd_default_set_arch_mach (abfd, bfd_arch_m68hc12, bfd_mach_m6812);
520 break;
521 case EF_M68HCS12_MACH:
522 bfd_default_set_arch_mach (abfd, bfd_arch_m68hc12, bfd_mach_m6812s);
523 break;
524 case EF_M68HC11_GENERIC:
525 bfd_default_set_arch_mach (abfd, bfd_arch_m68hc12,
526 bfd_mach_m6812_default);
527 break;
528 default:
529 return FALSE;
530 }
531 return TRUE;
532 }
533
534 /* Specific sections:
535 - The .page0 is a data section that is mapped in [0x0000..0x00FF].
536 Page0 accesses are faster on the M68HC12.
537 - The .vectors is the section that represents the interrupt
538 vectors. */
539 static const struct bfd_elf_special_section elf32_m68hc12_special_sections[] =
540 {
541 { STRING_COMMA_LEN (".eeprom"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
542 { STRING_COMMA_LEN (".page0"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
543 { STRING_COMMA_LEN (".softregs"), 0, SHT_NOBITS, SHF_ALLOC + SHF_WRITE },
544 { STRING_COMMA_LEN (".vectors"), 0, SHT_PROGBITS, SHF_ALLOC },
545 { NULL, 0, 0, 0, 0 }
546 };
547 \f
548 #define ELF_ARCH bfd_arch_m68hc12
549 #define ELF_MACHINE_CODE EM_68HC12
550 #define ELF_MAXPAGESIZE 0x1000
551
552 #define TARGET_BIG_SYM bfd_elf32_m68hc12_vec
553 #define TARGET_BIG_NAME "elf32-m68hc12"
554
555 #define elf_info_to_howto 0
556 #define elf_info_to_howto_rel m68hc11_info_to_howto_rel
557 #define elf_backend_check_relocs elf32_m68hc11_check_relocs
558 #define elf_backend_relocate_section elf32_m68hc11_relocate_section
559 #define elf_backend_object_p m68hc12_elf_set_mach_from_flags
560 #define elf_backend_final_write_processing 0
561 #define elf_backend_can_gc_sections 1
562 #define elf_backend_special_sections elf32_m68hc12_special_sections
563 #define elf_backend_post_process_headers elf32_m68hc11_post_process_headers
564 #define elf_backend_add_symbol_hook elf32_m68hc11_add_symbol_hook
565
566 #define bfd_elf32_bfd_link_hash_table_create \
567 m68hc12_elf_bfd_link_hash_table_create
568 #define bfd_elf32_bfd_link_hash_table_free \
569 m68hc11_elf_bfd_link_hash_table_free
570 #define bfd_elf32_bfd_merge_private_bfd_data \
571 _bfd_m68hc11_elf_merge_private_bfd_data
572 #define bfd_elf32_bfd_set_private_flags _bfd_m68hc11_elf_set_private_flags
573 #define bfd_elf32_bfd_print_private_bfd_data \
574 _bfd_m68hc11_elf_print_private_bfd_data
575
576 #include "elf32-target.h"
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