2007-06-01 Steve Ellcey <sje@cup.hp.com>
[binutils.git] / bfd / elf32-m68hc11.c
blob00253978df0bf3d859556789cd7ed998be2e8616
1 /* Motorola 68HC11-specific support for 32-bit ELF
2 Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
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))
7 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
23 #include "sysdep.h"
24 #include "bfd.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"
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 *);
38 /* Trampoline generation. */
39 static bfd_boolean m68hc11_elf_size_one_stub
40 (struct bfd_hash_entry *gen_entry, void *in_arg);
41 static bfd_boolean m68hc11_elf_build_one_stub
42 (struct bfd_hash_entry *gen_entry, void *in_arg);
43 static struct bfd_link_hash_table* m68hc11_elf_bfd_link_hash_table_create
44 (bfd* abfd);
46 /* Linker relaxation. */
47 static bfd_boolean m68hc11_elf_relax_section
48 (bfd *, asection *, struct bfd_link_info *, bfd_boolean *);
49 static void m68hc11_elf_relax_delete_bytes
50 (bfd *, asection *, bfd_vma, int);
51 static void m68hc11_relax_group
52 (bfd *, asection *, bfd_byte *, unsigned, unsigned long, unsigned long);
53 static int compare_reloc (const void *, const void *);
55 /* Use REL instead of RELA to save space */
56 #define USE_REL 1
58 /* The Motorola 68HC11 microcontroller only addresses 64Kb but we also
59 support a memory bank switching mechanism similar to 68HC12.
60 We must handle 8 and 16-bit relocations. The 32-bit relocation
61 are used for debugging sections (DWARF2) to represent a virtual
62 address.
63 The 3-bit and 16-bit PC rel relocation is only used by 68HC12. */
64 static reloc_howto_type elf_m68hc11_howto_table[] = {
65 /* This reloc does nothing. */
66 HOWTO (R_M68HC11_NONE, /* type */
67 0, /* rightshift */
68 2, /* size (0 = byte, 1 = short, 2 = long) */
69 32, /* bitsize */
70 FALSE, /* pc_relative */
71 0, /* bitpos */
72 complain_overflow_dont,/* complain_on_overflow */
73 bfd_elf_generic_reloc, /* special_function */
74 "R_M68HC11_NONE", /* name */
75 FALSE, /* partial_inplace */
76 0, /* src_mask */
77 0, /* dst_mask */
78 FALSE), /* pcrel_offset */
80 /* A 8 bit absolute relocation */
81 HOWTO (R_M68HC11_8, /* type */
82 0, /* rightshift */
83 0, /* size (0 = byte, 1 = short, 2 = long) */
84 8, /* bitsize */
85 FALSE, /* pc_relative */
86 0, /* bitpos */
87 complain_overflow_bitfield, /* complain_on_overflow */
88 bfd_elf_generic_reloc, /* special_function */
89 "R_M68HC11_8", /* name */
90 FALSE, /* partial_inplace */
91 0x00ff, /* src_mask */
92 0x00ff, /* dst_mask */
93 FALSE), /* pcrel_offset */
95 /* A 8 bit absolute relocation (upper address) */
96 HOWTO (R_M68HC11_HI8, /* type */
97 8, /* rightshift */
98 0, /* size (0 = byte, 1 = short, 2 = long) */
99 8, /* bitsize */
100 FALSE, /* pc_relative */
101 0, /* bitpos */
102 complain_overflow_bitfield, /* complain_on_overflow */
103 bfd_elf_generic_reloc, /* special_function */
104 "R_M68HC11_HI8", /* name */
105 FALSE, /* partial_inplace */
106 0x00ff, /* src_mask */
107 0x00ff, /* dst_mask */
108 FALSE), /* pcrel_offset */
110 /* A 8 bit absolute relocation (upper address) */
111 HOWTO (R_M68HC11_LO8, /* type */
112 0, /* rightshift */
113 0, /* size (0 = byte, 1 = short, 2 = long) */
114 8, /* bitsize */
115 FALSE, /* pc_relative */
116 0, /* bitpos */
117 complain_overflow_dont, /* complain_on_overflow */
118 bfd_elf_generic_reloc, /* special_function */
119 "R_M68HC11_LO8", /* name */
120 FALSE, /* partial_inplace */
121 0x00ff, /* src_mask */
122 0x00ff, /* dst_mask */
123 FALSE), /* pcrel_offset */
125 /* A 8 bit PC-rel relocation */
126 HOWTO (R_M68HC11_PCREL_8, /* type */
127 0, /* rightshift */
128 0, /* size (0 = byte, 1 = short, 2 = long) */
129 8, /* bitsize */
130 TRUE, /* pc_relative */
131 0, /* bitpos */
132 complain_overflow_bitfield, /* complain_on_overflow */
133 bfd_elf_generic_reloc, /* special_function */
134 "R_M68HC11_PCREL_8", /* name */
135 FALSE, /* partial_inplace */
136 0x00ff, /* src_mask */
137 0x00ff, /* dst_mask */
138 TRUE), /* pcrel_offset */
140 /* A 16 bit absolute relocation */
141 HOWTO (R_M68HC11_16, /* type */
142 0, /* rightshift */
143 1, /* size (0 = byte, 1 = short, 2 = long) */
144 16, /* bitsize */
145 FALSE, /* pc_relative */
146 0, /* bitpos */
147 complain_overflow_dont /*bitfield */ , /* complain_on_overflow */
148 bfd_elf_generic_reloc, /* special_function */
149 "R_M68HC11_16", /* name */
150 FALSE, /* partial_inplace */
151 0xffff, /* src_mask */
152 0xffff, /* dst_mask */
153 FALSE), /* pcrel_offset */
155 /* A 32 bit absolute relocation. This one is never used for the
156 code relocation. It's used by gas for -gstabs generation. */
157 HOWTO (R_M68HC11_32, /* type */
158 0, /* rightshift */
159 2, /* size (0 = byte, 1 = short, 2 = long) */
160 32, /* bitsize */
161 FALSE, /* pc_relative */
162 0, /* bitpos */
163 complain_overflow_bitfield, /* complain_on_overflow */
164 bfd_elf_generic_reloc, /* special_function */
165 "R_M68HC11_32", /* name */
166 FALSE, /* partial_inplace */
167 0xffffffff, /* src_mask */
168 0xffffffff, /* dst_mask */
169 FALSE), /* pcrel_offset */
171 /* A 3 bit absolute relocation */
172 HOWTO (R_M68HC11_3B, /* type */
173 0, /* rightshift */
174 0, /* size (0 = byte, 1 = short, 2 = long) */
175 3, /* bitsize */
176 FALSE, /* pc_relative */
177 0, /* bitpos */
178 complain_overflow_bitfield, /* complain_on_overflow */
179 bfd_elf_generic_reloc, /* special_function */
180 "R_M68HC11_4B", /* name */
181 FALSE, /* partial_inplace */
182 0x003, /* src_mask */
183 0x003, /* dst_mask */
184 FALSE), /* pcrel_offset */
186 /* A 16 bit PC-rel relocation */
187 HOWTO (R_M68HC11_PCREL_16, /* type */
188 0, /* rightshift */
189 1, /* size (0 = byte, 1 = short, 2 = long) */
190 16, /* bitsize */
191 TRUE, /* pc_relative */
192 0, /* bitpos */
193 complain_overflow_dont, /* complain_on_overflow */
194 bfd_elf_generic_reloc, /* special_function */
195 "R_M68HC11_PCREL_16", /* name */
196 FALSE, /* partial_inplace */
197 0xffff, /* src_mask */
198 0xffff, /* dst_mask */
199 TRUE), /* pcrel_offset */
201 /* GNU extension to record C++ vtable hierarchy */
202 HOWTO (R_M68HC11_GNU_VTINHERIT, /* type */
203 0, /* rightshift */
204 1, /* size (0 = byte, 1 = short, 2 = long) */
205 0, /* bitsize */
206 FALSE, /* pc_relative */
207 0, /* bitpos */
208 complain_overflow_dont, /* complain_on_overflow */
209 NULL, /* special_function */
210 "R_M68HC11_GNU_VTINHERIT", /* name */
211 FALSE, /* partial_inplace */
212 0, /* src_mask */
213 0, /* dst_mask */
214 FALSE), /* pcrel_offset */
216 /* GNU extension to record C++ vtable member usage */
217 HOWTO (R_M68HC11_GNU_VTENTRY, /* type */
218 0, /* rightshift */
219 1, /* size (0 = byte, 1 = short, 2 = long) */
220 0, /* bitsize */
221 FALSE, /* pc_relative */
222 0, /* bitpos */
223 complain_overflow_dont, /* complain_on_overflow */
224 _bfd_elf_rel_vtable_reloc_fn, /* special_function */
225 "R_M68HC11_GNU_VTENTRY", /* name */
226 FALSE, /* partial_inplace */
227 0, /* src_mask */
228 0, /* dst_mask */
229 FALSE), /* pcrel_offset */
231 /* A 24 bit relocation */
232 HOWTO (R_M68HC11_24, /* type */
233 0, /* rightshift */
234 1, /* size (0 = byte, 1 = short, 2 = long) */
235 24, /* bitsize */
236 FALSE, /* pc_relative */
237 0, /* bitpos */
238 complain_overflow_bitfield, /* complain_on_overflow */
239 bfd_elf_generic_reloc, /* special_function */
240 "R_M68HC11_24", /* name */
241 FALSE, /* partial_inplace */
242 0xffffff, /* src_mask */
243 0xffffff, /* dst_mask */
244 FALSE), /* pcrel_offset */
246 /* A 16-bit low relocation */
247 HOWTO (R_M68HC11_LO16, /* type */
248 0, /* rightshift */
249 1, /* size (0 = byte, 1 = short, 2 = long) */
250 16, /* bitsize */
251 FALSE, /* pc_relative */
252 0, /* bitpos */
253 complain_overflow_bitfield, /* complain_on_overflow */
254 bfd_elf_generic_reloc, /* special_function */
255 "R_M68HC11_LO16", /* name */
256 FALSE, /* partial_inplace */
257 0xffff, /* src_mask */
258 0xffff, /* dst_mask */
259 FALSE), /* pcrel_offset */
261 /* A page relocation */
262 HOWTO (R_M68HC11_PAGE, /* type */
263 0, /* rightshift */
264 0, /* size (0 = byte, 1 = short, 2 = long) */
265 8, /* bitsize */
266 FALSE, /* pc_relative */
267 0, /* bitpos */
268 complain_overflow_bitfield, /* complain_on_overflow */
269 bfd_elf_generic_reloc, /* special_function */
270 "R_M68HC11_PAGE", /* name */
271 FALSE, /* partial_inplace */
272 0x00ff, /* src_mask */
273 0x00ff, /* dst_mask */
274 FALSE), /* pcrel_offset */
276 EMPTY_HOWTO (14),
277 EMPTY_HOWTO (15),
278 EMPTY_HOWTO (16),
279 EMPTY_HOWTO (17),
280 EMPTY_HOWTO (18),
281 EMPTY_HOWTO (19),
283 /* Mark beginning of a jump instruction (any form). */
284 HOWTO (R_M68HC11_RL_JUMP, /* type */
285 0, /* rightshift */
286 1, /* size (0 = byte, 1 = short, 2 = long) */
287 0, /* bitsize */
288 FALSE, /* pc_relative */
289 0, /* bitpos */
290 complain_overflow_dont, /* complain_on_overflow */
291 m68hc11_elf_ignore_reloc, /* special_function */
292 "R_M68HC11_RL_JUMP", /* name */
293 TRUE, /* partial_inplace */
294 0, /* src_mask */
295 0, /* dst_mask */
296 TRUE), /* pcrel_offset */
298 /* Mark beginning of Gcc relaxation group instruction. */
299 HOWTO (R_M68HC11_RL_GROUP, /* type */
300 0, /* rightshift */
301 1, /* size (0 = byte, 1 = short, 2 = long) */
302 0, /* bitsize */
303 FALSE, /* pc_relative */
304 0, /* bitpos */
305 complain_overflow_dont, /* complain_on_overflow */
306 m68hc11_elf_ignore_reloc, /* special_function */
307 "R_M68HC11_RL_GROUP", /* name */
308 TRUE, /* partial_inplace */
309 0, /* src_mask */
310 0, /* dst_mask */
311 TRUE), /* pcrel_offset */
314 /* Map BFD reloc types to M68HC11 ELF reloc types. */
316 struct m68hc11_reloc_map
318 bfd_reloc_code_real_type bfd_reloc_val;
319 unsigned char elf_reloc_val;
322 static const struct m68hc11_reloc_map m68hc11_reloc_map[] = {
323 {BFD_RELOC_NONE, R_M68HC11_NONE,},
324 {BFD_RELOC_8, R_M68HC11_8},
325 {BFD_RELOC_M68HC11_HI8, R_M68HC11_HI8},
326 {BFD_RELOC_M68HC11_LO8, R_M68HC11_LO8},
327 {BFD_RELOC_8_PCREL, R_M68HC11_PCREL_8},
328 {BFD_RELOC_16_PCREL, R_M68HC11_PCREL_16},
329 {BFD_RELOC_16, R_M68HC11_16},
330 {BFD_RELOC_32, R_M68HC11_32},
331 {BFD_RELOC_M68HC11_3B, R_M68HC11_3B},
333 {BFD_RELOC_VTABLE_INHERIT, R_M68HC11_GNU_VTINHERIT},
334 {BFD_RELOC_VTABLE_ENTRY, R_M68HC11_GNU_VTENTRY},
336 {BFD_RELOC_M68HC11_LO16, R_M68HC11_LO16},
337 {BFD_RELOC_M68HC11_PAGE, R_M68HC11_PAGE},
338 {BFD_RELOC_M68HC11_24, R_M68HC11_24},
340 {BFD_RELOC_M68HC11_RL_JUMP, R_M68HC11_RL_JUMP},
341 {BFD_RELOC_M68HC11_RL_GROUP, R_M68HC11_RL_GROUP},
344 static reloc_howto_type *
345 bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
346 bfd_reloc_code_real_type code)
348 unsigned int i;
350 for (i = 0;
351 i < sizeof (m68hc11_reloc_map) / sizeof (struct m68hc11_reloc_map);
352 i++)
354 if (m68hc11_reloc_map[i].bfd_reloc_val == code)
355 return &elf_m68hc11_howto_table[m68hc11_reloc_map[i].elf_reloc_val];
358 return NULL;
361 static reloc_howto_type *
362 bfd_elf32_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
363 const char *r_name)
365 unsigned int i;
367 for (i = 0;
368 i < (sizeof (elf_m68hc11_howto_table)
369 / sizeof (elf_m68hc11_howto_table[0]));
370 i++)
371 if (elf_m68hc11_howto_table[i].name != NULL
372 && strcasecmp (elf_m68hc11_howto_table[i].name, r_name) == 0)
373 return &elf_m68hc11_howto_table[i];
375 return NULL;
378 /* Set the howto pointer for an M68HC11 ELF reloc. */
380 static void
381 m68hc11_info_to_howto_rel (bfd *abfd ATTRIBUTE_UNUSED,
382 arelent *cache_ptr, Elf_Internal_Rela *dst)
384 unsigned int r_type;
386 r_type = ELF32_R_TYPE (dst->r_info);
387 BFD_ASSERT (r_type < (unsigned int) R_M68HC11_max);
388 cache_ptr->howto = &elf_m68hc11_howto_table[r_type];
392 /* Far trampoline generation. */
394 /* Build a 68HC11 trampoline stub. */
395 static bfd_boolean
396 m68hc11_elf_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
398 struct elf32_m68hc11_stub_hash_entry *stub_entry;
399 struct bfd_link_info *info;
400 struct m68hc11_elf_link_hash_table *htab;
401 asection *stub_sec;
402 bfd *stub_bfd;
403 bfd_byte *loc;
404 bfd_vma sym_value, phys_page, phys_addr;
406 /* Massage our args to the form they really have. */
407 stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
408 info = (struct bfd_link_info *) in_arg;
410 htab = m68hc11_elf_hash_table (info);
412 stub_sec = stub_entry->stub_sec;
414 /* Make a note of the offset within the stubs for this entry. */
415 stub_entry->stub_offset = stub_sec->size;
416 stub_sec->size += 10;
417 loc = stub_sec->contents + stub_entry->stub_offset;
419 stub_bfd = stub_sec->owner;
421 /* Create the trampoline call stub:
423 pshb
424 ldab #%page(symbol)
425 ldy #%addr(symbol)
426 jmp __trampoline
429 sym_value = (stub_entry->target_value
430 + stub_entry->target_section->output_offset
431 + stub_entry->target_section->output_section->vma);
432 phys_addr = m68hc11_phys_addr (&htab->pinfo, sym_value);
433 phys_page = m68hc11_phys_page (&htab->pinfo, sym_value);
435 /* pshb; ldab #%page(sym) */
436 bfd_put_8 (stub_bfd, 0x37, loc);
437 bfd_put_8 (stub_bfd, 0xC6, loc + 1);
438 bfd_put_8 (stub_bfd, phys_page, loc + 2);
439 loc += 3;
441 /* ldy #%addr(sym) */
442 bfd_put_8 (stub_bfd, 0x18, loc);
443 bfd_put_8 (stub_bfd, 0xCE, loc + 1);
444 bfd_put_16 (stub_bfd, phys_addr, loc + 2);
445 loc += 4;
447 /* jmp __trampoline */
448 bfd_put_8 (stub_bfd, 0x7E, loc);
449 bfd_put_16 (stub_bfd, htab->pinfo.trampoline_addr, loc + 1);
451 return TRUE;
454 /* As above, but don't actually build the stub. Just bump offset so
455 we know stub section sizes. */
457 static bfd_boolean
458 m68hc11_elf_size_one_stub (struct bfd_hash_entry *gen_entry,
459 void *in_arg ATTRIBUTE_UNUSED)
461 struct elf32_m68hc11_stub_hash_entry *stub_entry;
463 /* Massage our args to the form they really have. */
464 stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
466 stub_entry->stub_sec->size += 10;
467 return TRUE;
470 /* Create a 68HC11 ELF linker hash table. */
472 static struct bfd_link_hash_table *
473 m68hc11_elf_bfd_link_hash_table_create (bfd *abfd)
475 struct m68hc11_elf_link_hash_table *ret;
477 ret = m68hc11_elf_hash_table_create (abfd);
478 if (ret == (struct m68hc11_elf_link_hash_table *) NULL)
479 return NULL;
481 ret->size_one_stub = m68hc11_elf_size_one_stub;
482 ret->build_one_stub = m68hc11_elf_build_one_stub;
484 return &ret->root.root;
488 /* 68HC11 Linker Relaxation. */
490 struct m68hc11_direct_relax
492 const char *name;
493 unsigned char code;
494 unsigned char direct_code;
495 } m68hc11_direct_relax_table[] = {
496 { "adca", 0xB9, 0x99 },
497 { "adcb", 0xF9, 0xD9 },
498 { "adda", 0xBB, 0x9B },
499 { "addb", 0xFB, 0xDB },
500 { "addd", 0xF3, 0xD3 },
501 { "anda", 0xB4, 0x94 },
502 { "andb", 0xF4, 0xD4 },
503 { "cmpa", 0xB1, 0x91 },
504 { "cmpb", 0xF1, 0xD1 },
505 { "cpd", 0xB3, 0x93 },
506 { "cpxy", 0xBC, 0x9C },
507 /* { "cpy", 0xBC, 0x9C }, */
508 { "eora", 0xB8, 0x98 },
509 { "eorb", 0xF8, 0xD8 },
510 { "jsr", 0xBD, 0x9D },
511 { "ldaa", 0xB6, 0x96 },
512 { "ldab", 0xF6, 0xD6 },
513 { "ldd", 0xFC, 0xDC },
514 { "lds", 0xBE, 0x9E },
515 { "ldxy", 0xFE, 0xDE },
516 /* { "ldy", 0xFE, 0xDE },*/
517 { "oraa", 0xBA, 0x9A },
518 { "orab", 0xFA, 0xDA },
519 { "sbca", 0xB2, 0x92 },
520 { "sbcb", 0xF2, 0xD2 },
521 { "staa", 0xB7, 0x97 },
522 { "stab", 0xF7, 0xD7 },
523 { "std", 0xFD, 0xDD },
524 { "sts", 0xBF, 0x9F },
525 { "stxy", 0xFF, 0xDF },
526 /* { "sty", 0xFF, 0xDF },*/
527 { "suba", 0xB0, 0x90 },
528 { "subb", 0xF0, 0xD0 },
529 { "subd", 0xB3, 0x93 },
530 { 0, 0, 0 }
533 static struct m68hc11_direct_relax *
534 find_relaxable_insn (unsigned char code)
536 int i;
538 for (i = 0; m68hc11_direct_relax_table[i].name; i++)
539 if (m68hc11_direct_relax_table[i].code == code)
540 return &m68hc11_direct_relax_table[i];
542 return 0;
545 static int
546 compare_reloc (const void *e1, const void *e2)
548 const Elf_Internal_Rela *i1 = (const Elf_Internal_Rela *) e1;
549 const Elf_Internal_Rela *i2 = (const Elf_Internal_Rela *) e2;
551 if (i1->r_offset == i2->r_offset)
552 return 0;
553 else
554 return i1->r_offset < i2->r_offset ? -1 : 1;
557 #define M6811_OP_LDX_IMMEDIATE (0xCE)
559 static void
560 m68hc11_relax_group (bfd *abfd, asection *sec, bfd_byte *contents,
561 unsigned value, unsigned long offset,
562 unsigned long end_group)
564 unsigned char code;
565 unsigned long start_offset;
566 unsigned long ldx_offset = offset;
567 unsigned long ldx_size;
568 int can_delete_ldx;
569 int relax_ldy = 0;
571 /* First instruction of the relax group must be a
572 LDX #value or LDY #value. If this is not the case,
573 ignore the relax group. */
574 code = bfd_get_8 (abfd, contents + offset);
575 if (code == 0x18)
577 relax_ldy++;
578 offset++;
579 code = bfd_get_8 (abfd, contents + offset);
581 ldx_size = offset - ldx_offset + 3;
582 offset += 3;
583 if (code != M6811_OP_LDX_IMMEDIATE || offset >= end_group)
584 return;
587 /* We can remove the LDX/LDY only when all bset/brclr instructions
588 of the relax group have been converted to use direct addressing
589 mode. */
590 can_delete_ldx = 1;
591 while (offset < end_group)
593 unsigned isize;
594 unsigned new_value;
595 int bset_use_y;
597 bset_use_y = 0;
598 start_offset = offset;
599 code = bfd_get_8 (abfd, contents + offset);
600 if (code == 0x18)
602 bset_use_y++;
603 offset++;
604 code = bfd_get_8 (abfd, contents + offset);
607 /* Check the instruction and translate to use direct addressing mode. */
608 switch (code)
610 /* bset */
611 case 0x1C:
612 code = 0x14;
613 isize = 3;
614 break;
616 /* brclr */
617 case 0x1F:
618 code = 0x13;
619 isize = 4;
620 break;
622 /* brset */
623 case 0x1E:
624 code = 0x12;
625 isize = 4;
626 break;
628 /* bclr */
629 case 0x1D:
630 code = 0x15;
631 isize = 3;
632 break;
634 /* This instruction is not recognized and we are not
635 at end of the relax group. Ignore and don't remove
636 the first LDX (we don't know what it is used for...). */
637 default:
638 return;
640 new_value = (unsigned) bfd_get_8 (abfd, contents + offset + 1);
641 new_value += value;
642 if ((new_value & 0xff00) == 0 && bset_use_y == relax_ldy)
644 bfd_put_8 (abfd, code, contents + offset);
645 bfd_put_8 (abfd, new_value, contents + offset + 1);
646 if (start_offset != offset)
648 m68hc11_elf_relax_delete_bytes (abfd, sec, start_offset,
649 offset - start_offset);
650 end_group--;
653 else
655 can_delete_ldx = 0;
657 offset = start_offset + isize;
659 if (can_delete_ldx)
661 /* Remove the move instruction (3 or 4 bytes win). */
662 m68hc11_elf_relax_delete_bytes (abfd, sec, ldx_offset, ldx_size);
666 /* This function handles relaxing for the 68HC11.
669 and somewhat more difficult to support. */
671 static bfd_boolean
672 m68hc11_elf_relax_section (bfd *abfd, asection *sec,
673 struct bfd_link_info *link_info, bfd_boolean *again)
675 Elf_Internal_Shdr *symtab_hdr;
676 Elf_Internal_Shdr *shndx_hdr;
677 Elf_Internal_Rela *internal_relocs;
678 Elf_Internal_Rela *free_relocs = NULL;
679 Elf_Internal_Rela *irel, *irelend;
680 bfd_byte *contents = NULL;
681 bfd_byte *free_contents = NULL;
682 Elf32_External_Sym *free_extsyms = NULL;
683 Elf_Internal_Rela *prev_insn_branch = NULL;
684 Elf_Internal_Rela *prev_insn_group = NULL;
685 unsigned insn_group_value = 0;
686 Elf_Internal_Sym *isymbuf = NULL;
688 /* Assume nothing changes. */
689 *again = FALSE;
691 /* We don't have to do anything for a relocatable link, if
692 this section does not have relocs, or if this is not a
693 code section. */
694 if (link_info->relocatable
695 || (sec->flags & SEC_RELOC) == 0
696 || sec->reloc_count == 0
697 || (sec->flags & SEC_CODE) == 0)
698 return TRUE;
700 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
701 shndx_hdr = &elf_tdata (abfd)->symtab_shndx_hdr;
703 /* Get a copy of the native relocations. */
704 internal_relocs = (_bfd_elf_link_read_relocs
705 (abfd, sec, (PTR) NULL, (Elf_Internal_Rela *) NULL,
706 link_info->keep_memory));
707 if (internal_relocs == NULL)
708 goto error_return;
709 if (! link_info->keep_memory)
710 free_relocs = internal_relocs;
712 /* Checking for branch relaxation relies on the relocations to
713 be sorted on 'r_offset'. This is not guaranteed so we must sort. */
714 qsort (internal_relocs, sec->reloc_count, sizeof (Elf_Internal_Rela),
715 compare_reloc);
717 /* Walk through them looking for relaxing opportunities. */
718 irelend = internal_relocs + sec->reloc_count;
719 for (irel = internal_relocs; irel < irelend; irel++)
721 bfd_vma symval;
722 bfd_vma value;
723 Elf_Internal_Sym *isym;
724 asection *sym_sec;
725 int is_far = 0;
727 /* If this isn't something that can be relaxed, then ignore
728 this reloc. */
729 if (ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_16
730 && ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_RL_JUMP
731 && ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_RL_GROUP)
733 prev_insn_branch = 0;
734 prev_insn_group = 0;
735 continue;
738 /* Get the section contents if we haven't done so already. */
739 if (contents == NULL)
741 /* Get cached copy if it exists. */
742 if (elf_section_data (sec)->this_hdr.contents != NULL)
743 contents = elf_section_data (sec)->this_hdr.contents;
744 else
746 /* Go get them off disk. */
747 if (!bfd_malloc_and_get_section (abfd, sec, &contents))
748 goto error_return;
752 /* Try to eliminate an unconditional 8 bit pc-relative branch
753 which immediately follows a conditional 8 bit pc-relative
754 branch around the unconditional branch.
756 original: new:
757 bCC lab1 bCC' lab2
758 bra lab2
759 lab1: lab1:
761 This happens when the bCC can't reach lab2 at assembly time,
762 but due to other relaxations it can reach at link time. */
763 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_RL_JUMP)
765 Elf_Internal_Rela *nrel;
766 unsigned char code;
767 unsigned char roffset;
769 prev_insn_branch = 0;
770 prev_insn_group = 0;
772 /* Do nothing if this reloc is the last byte in the section. */
773 if (irel->r_offset + 2 >= sec->size)
774 continue;
776 /* See if the next instruction is an unconditional pc-relative
777 branch, more often than not this test will fail, so we
778 test it first to speed things up. */
779 code = bfd_get_8 (abfd, contents + irel->r_offset + 2);
780 if (code != 0x7e)
781 continue;
783 /* Also make sure the next relocation applies to the next
784 instruction and that it's a pc-relative 8 bit branch. */
785 nrel = irel + 1;
786 if (nrel == irelend
787 || irel->r_offset + 3 != nrel->r_offset
788 || ELF32_R_TYPE (nrel->r_info) != (int) R_M68HC11_16)
789 continue;
791 /* Make sure our destination immediately follows the
792 unconditional branch. */
793 roffset = bfd_get_8 (abfd, contents + irel->r_offset + 1);
794 if (roffset != 3)
795 continue;
797 prev_insn_branch = irel;
798 prev_insn_group = 0;
799 continue;
802 /* Read this BFD's symbols if we haven't done so already. */
803 if (isymbuf == NULL && symtab_hdr->sh_info != 0)
805 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
806 if (isymbuf == NULL)
807 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
808 symtab_hdr->sh_info, 0,
809 NULL, NULL, NULL);
810 if (isymbuf == NULL)
811 goto error_return;
814 /* Get the value of the symbol referred to by the reloc. */
815 if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
817 /* A local symbol. */
818 isym = isymbuf + ELF32_R_SYM (irel->r_info);
819 is_far = isym->st_other & STO_M68HC12_FAR;
820 sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
821 symval = (isym->st_value
822 + sym_sec->output_section->vma
823 + sym_sec->output_offset);
825 else
827 unsigned long indx;
828 struct elf_link_hash_entry *h;
830 /* An external symbol. */
831 indx = ELF32_R_SYM (irel->r_info) - symtab_hdr->sh_info;
832 h = elf_sym_hashes (abfd)[indx];
833 BFD_ASSERT (h != NULL);
834 if (h->root.type != bfd_link_hash_defined
835 && h->root.type != bfd_link_hash_defweak)
837 /* This appears to be a reference to an undefined
838 symbol. Just ignore it--it will be caught by the
839 regular reloc processing. */
840 prev_insn_branch = 0;
841 prev_insn_group = 0;
842 continue;
845 is_far = h->other & STO_M68HC12_FAR;
846 isym = 0;
847 sym_sec = h->root.u.def.section;
848 symval = (h->root.u.def.value
849 + sym_sec->output_section->vma
850 + sym_sec->output_offset);
853 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_RL_GROUP)
855 prev_insn_branch = 0;
856 prev_insn_group = 0;
858 /* Do nothing if this reloc is the last byte in the section. */
859 if (irel->r_offset == sec->size)
860 continue;
862 prev_insn_group = irel;
863 insn_group_value = isym->st_value;
864 continue;
867 /* When we relax some bytes, the size of our section changes.
868 This affects the layout of next input sections that go in our
869 output section. When the symbol is part of another section that
870 will go in the same output section as the current one, it's
871 final address may now be incorrect (too far). We must let the
872 linker re-compute all section offsets before processing this
873 reloc. Code example:
875 Initial Final
876 .sect .text section size = 6 section size = 4
877 jmp foo
878 jmp bar
879 .sect .text.foo_bar output_offset = 6 output_offset = 4
880 foo: rts
881 bar: rts
883 If we process the reloc now, the jmp bar is replaced by a
884 relative branch to the initial bar address (output_offset 6). */
885 if (*again && sym_sec != sec
886 && sym_sec->output_section == sec->output_section)
888 prev_insn_group = 0;
889 prev_insn_branch = 0;
890 continue;
893 value = symval;
894 /* Try to turn a far branch to a near branch. */
895 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_16
896 && prev_insn_branch)
898 bfd_vma offset;
899 unsigned char code;
901 offset = value - (prev_insn_branch->r_offset
902 + sec->output_section->vma
903 + sec->output_offset + 2);
905 /* If the offset is still out of -128..+127 range,
906 leave that far branch unchanged. */
907 if ((offset & 0xff80) != 0 && (offset & 0xff80) != 0xff80)
909 prev_insn_branch = 0;
910 continue;
913 /* Shrink the branch. */
914 code = bfd_get_8 (abfd, contents + prev_insn_branch->r_offset);
915 if (code == 0x7e)
917 code = 0x20;
918 bfd_put_8 (abfd, code, contents + prev_insn_branch->r_offset);
919 bfd_put_8 (abfd, 0xff,
920 contents + prev_insn_branch->r_offset + 1);
921 irel->r_offset = prev_insn_branch->r_offset + 1;
922 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
923 R_M68HC11_PCREL_8);
924 m68hc11_elf_relax_delete_bytes (abfd, sec,
925 irel->r_offset + 1, 1);
927 else
929 code ^= 0x1;
930 bfd_put_8 (abfd, code, contents + prev_insn_branch->r_offset);
931 bfd_put_8 (abfd, 0xff,
932 contents + prev_insn_branch->r_offset + 1);
933 irel->r_offset = prev_insn_branch->r_offset + 1;
934 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
935 R_M68HC11_PCREL_8);
936 m68hc11_elf_relax_delete_bytes (abfd, sec,
937 irel->r_offset + 1, 3);
939 prev_insn_branch = 0;
940 *again = TRUE;
943 /* Try to turn a 16 bit address into a 8 bit page0 address. */
944 else if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_16
945 && (value & 0xff00) == 0)
947 unsigned char code;
948 unsigned short offset;
949 struct m68hc11_direct_relax *rinfo;
951 prev_insn_branch = 0;
952 offset = bfd_get_16 (abfd, contents + irel->r_offset);
953 offset += value;
954 if ((offset & 0xff00) != 0)
956 prev_insn_group = 0;
957 continue;
960 if (prev_insn_group)
962 unsigned long old_sec_size = sec->size;
964 /* Note that we've changed the relocation contents, etc. */
965 elf_section_data (sec)->relocs = internal_relocs;
966 free_relocs = NULL;
968 elf_section_data (sec)->this_hdr.contents = contents;
969 free_contents = NULL;
971 symtab_hdr->contents = (bfd_byte *) isymbuf;
972 free_extsyms = NULL;
974 m68hc11_relax_group (abfd, sec, contents, offset,
975 prev_insn_group->r_offset,
976 insn_group_value);
977 irel = prev_insn_group;
978 prev_insn_group = 0;
979 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
980 R_M68HC11_NONE);
981 if (sec->size != old_sec_size)
982 *again = TRUE;
983 continue;
986 /* Get the opcode. */
987 code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
988 rinfo = find_relaxable_insn (code);
989 if (rinfo == 0)
991 prev_insn_group = 0;
992 continue;
995 /* Note that we've changed the relocation contents, etc. */
996 elf_section_data (sec)->relocs = internal_relocs;
997 free_relocs = NULL;
999 elf_section_data (sec)->this_hdr.contents = contents;
1000 free_contents = NULL;
1002 symtab_hdr->contents = (bfd_byte *) isymbuf;
1003 free_extsyms = NULL;
1005 /* Fix the opcode. */
1006 /* printf ("A relaxable case : 0x%02x (%s)\n",
1007 code, rinfo->name); */
1008 bfd_put_8 (abfd, rinfo->direct_code,
1009 contents + irel->r_offset - 1);
1011 /* Delete one byte of data (upper byte of address). */
1012 m68hc11_elf_relax_delete_bytes (abfd, sec, irel->r_offset, 1);
1014 /* Fix the relocation's type. */
1015 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1016 R_M68HC11_8);
1018 /* That will change things, so, we should relax again. */
1019 *again = TRUE;
1021 else if (ELF32_R_TYPE (irel->r_info) == R_M68HC11_16 && !is_far)
1023 unsigned char code;
1024 bfd_vma offset;
1026 prev_insn_branch = 0;
1027 code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
1028 if (code == 0x7e || code == 0xbd)
1030 offset = value - (irel->r_offset
1031 + sec->output_section->vma
1032 + sec->output_offset + 1);
1033 offset += bfd_get_16 (abfd, contents + irel->r_offset);
1035 /* If the offset is still out of -128..+127 range,
1036 leave that far branch unchanged. */
1037 if ((offset & 0xff80) == 0 || (offset & 0xff80) == 0xff80)
1040 /* Note that we've changed the relocation contents, etc. */
1041 elf_section_data (sec)->relocs = internal_relocs;
1042 free_relocs = NULL;
1044 elf_section_data (sec)->this_hdr.contents = contents;
1045 free_contents = NULL;
1047 symtab_hdr->contents = (bfd_byte *) isymbuf;
1048 free_extsyms = NULL;
1050 /* Shrink the branch. */
1051 code = (code == 0x7e) ? 0x20 : 0x8d;
1052 bfd_put_8 (abfd, code,
1053 contents + irel->r_offset - 1);
1054 bfd_put_8 (abfd, 0xff,
1055 contents + irel->r_offset);
1056 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1057 R_M68HC11_PCREL_8);
1058 m68hc11_elf_relax_delete_bytes (abfd, sec,
1059 irel->r_offset + 1, 1);
1060 /* That will change things, so, we should relax again. */
1061 *again = TRUE;
1065 prev_insn_branch = 0;
1066 prev_insn_group = 0;
1069 if (free_relocs != NULL)
1071 free (free_relocs);
1072 free_relocs = NULL;
1075 if (free_contents != NULL)
1077 if (! link_info->keep_memory)
1078 free (free_contents);
1079 else
1081 /* Cache the section contents for elf_link_input_bfd. */
1082 elf_section_data (sec)->this_hdr.contents = contents;
1084 free_contents = NULL;
1087 if (free_extsyms != NULL)
1089 if (! link_info->keep_memory)
1090 free (free_extsyms);
1091 else
1093 /* Cache the symbols for elf_link_input_bfd. */
1094 symtab_hdr->contents = (unsigned char *) isymbuf;
1096 free_extsyms = NULL;
1099 return TRUE;
1101 error_return:
1102 if (free_relocs != NULL)
1103 free (free_relocs);
1104 if (free_contents != NULL)
1105 free (free_contents);
1106 if (free_extsyms != NULL)
1107 free (free_extsyms);
1108 return FALSE;
1111 /* Delete some bytes from a section while relaxing. */
1113 static void
1114 m68hc11_elf_relax_delete_bytes (bfd *abfd, asection *sec,
1115 bfd_vma addr, int count)
1117 Elf_Internal_Shdr *symtab_hdr;
1118 unsigned int sec_shndx;
1119 bfd_byte *contents;
1120 Elf_Internal_Rela *irel, *irelend;
1121 bfd_vma toaddr;
1122 Elf_Internal_Sym *isymbuf, *isym, *isymend;
1123 struct elf_link_hash_entry **sym_hashes;
1124 struct elf_link_hash_entry **end_hashes;
1125 unsigned int symcount;
1127 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1128 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
1130 sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
1132 contents = elf_section_data (sec)->this_hdr.contents;
1134 toaddr = sec->size;
1136 irel = elf_section_data (sec)->relocs;
1137 irelend = irel + sec->reloc_count;
1139 /* Actually delete the bytes. */
1140 memmove (contents + addr, contents + addr + count,
1141 (size_t) (toaddr - addr - count));
1143 sec->size -= count;
1145 /* Adjust all the relocs. */
1146 for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
1148 unsigned char code;
1149 unsigned char offset;
1150 unsigned short raddr;
1151 unsigned long old_offset;
1152 int branch_pos;
1154 old_offset = irel->r_offset;
1156 /* See if this reloc was for the bytes we have deleted, in which
1157 case we no longer care about it. Don't delete relocs which
1158 represent addresses, though. */
1159 if (ELF32_R_TYPE (irel->r_info) != R_M68HC11_RL_JUMP
1160 && irel->r_offset >= addr && irel->r_offset < addr + count)
1161 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1162 R_M68HC11_NONE);
1164 if (ELF32_R_TYPE (irel->r_info) == R_M68HC11_NONE)
1165 continue;
1167 /* Get the new reloc address. */
1168 if ((irel->r_offset > addr
1169 && irel->r_offset < toaddr))
1170 irel->r_offset -= count;
1172 /* If this is a PC relative reloc, see if the range it covers
1173 includes the bytes we have deleted. */
1174 switch (ELF32_R_TYPE (irel->r_info))
1176 default:
1177 break;
1179 case R_M68HC11_RL_JUMP:
1180 code = bfd_get_8 (abfd, contents + irel->r_offset);
1181 switch (code)
1183 /* jsr and jmp instruction are also marked with RL_JUMP
1184 relocs but no adjustment must be made. */
1185 case 0x7e:
1186 case 0x9d:
1187 case 0xbd:
1188 continue;
1190 case 0x12:
1191 case 0x13:
1192 branch_pos = 3;
1193 raddr = 4;
1195 /* Special case when we translate a brclr N,y into brclr *<addr>
1196 In this case, the 0x18 page2 prefix is removed.
1197 The reloc offset is not modified but the instruction
1198 size is reduced by 1. */
1199 if (old_offset == addr)
1200 raddr++;
1201 break;
1203 case 0x1e:
1204 case 0x1f:
1205 branch_pos = 3;
1206 raddr = 4;
1207 break;
1209 case 0x18:
1210 branch_pos = 4;
1211 raddr = 5;
1212 break;
1214 default:
1215 branch_pos = 1;
1216 raddr = 2;
1217 break;
1219 offset = bfd_get_8 (abfd, contents + irel->r_offset + branch_pos);
1220 raddr += old_offset;
1221 raddr += ((unsigned short) offset | ((offset & 0x80) ? 0xff00 : 0));
1222 if (irel->r_offset < addr && raddr > addr)
1224 offset -= count;
1225 bfd_put_8 (abfd, offset, contents + irel->r_offset + branch_pos);
1227 else if (irel->r_offset >= addr && raddr <= addr)
1229 offset += count;
1230 bfd_put_8 (abfd, offset, contents + irel->r_offset + branch_pos);
1232 else
1234 /*printf ("Not adjusted 0x%04x [0x%4x 0x%4x]\n", raddr,
1235 irel->r_offset, addr);*/
1238 break;
1242 /* Adjust the local symbols defined in this section. */
1243 isymend = isymbuf + symtab_hdr->sh_info;
1244 for (isym = isymbuf; isym < isymend; isym++)
1246 if (isym->st_shndx == sec_shndx
1247 && isym->st_value > addr
1248 && isym->st_value <= toaddr)
1249 isym->st_value -= count;
1252 /* Now adjust the global symbols defined in this section. */
1253 symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
1254 - symtab_hdr->sh_info);
1255 sym_hashes = elf_sym_hashes (abfd);
1256 end_hashes = sym_hashes + symcount;
1257 for (; sym_hashes < end_hashes; sym_hashes++)
1259 struct elf_link_hash_entry *sym_hash = *sym_hashes;
1260 if ((sym_hash->root.type == bfd_link_hash_defined
1261 || sym_hash->root.type == bfd_link_hash_defweak)
1262 && sym_hash->root.u.def.section == sec
1263 && sym_hash->root.u.def.value > addr
1264 && sym_hash->root.u.def.value <= toaddr)
1266 sym_hash->root.u.def.value -= count;
1271 /* Specific sections:
1272 - The .page0 is a data section that is mapped in [0x0000..0x00FF].
1273 Page0 accesses are faster on the M68HC11. Soft registers used by GCC-m6811
1274 are located in .page0.
1275 - The .vectors is the section that represents the interrupt
1276 vectors. */
1277 static const struct bfd_elf_special_section elf32_m68hc11_special_sections[] =
1279 { STRING_COMMA_LEN (".eeprom"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
1280 { STRING_COMMA_LEN (".page0"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
1281 { STRING_COMMA_LEN (".softregs"), 0, SHT_NOBITS, SHF_ALLOC + SHF_WRITE },
1282 { STRING_COMMA_LEN (".vectors"), 0, SHT_PROGBITS, SHF_ALLOC },
1283 { NULL, 0, 0, 0, 0 }
1286 #define ELF_ARCH bfd_arch_m68hc11
1287 #define ELF_MACHINE_CODE EM_68HC11
1288 #define ELF_MAXPAGESIZE 0x1000
1290 #define TARGET_BIG_SYM bfd_elf32_m68hc11_vec
1291 #define TARGET_BIG_NAME "elf32-m68hc11"
1293 #define elf_info_to_howto 0
1294 #define elf_info_to_howto_rel m68hc11_info_to_howto_rel
1295 #define bfd_elf32_bfd_relax_section m68hc11_elf_relax_section
1296 #define elf_backend_check_relocs elf32_m68hc11_check_relocs
1297 #define elf_backend_relocate_section elf32_m68hc11_relocate_section
1298 #define elf_backend_add_symbol_hook elf32_m68hc11_add_symbol_hook
1299 #define elf_backend_object_p 0
1300 #define elf_backend_final_write_processing 0
1301 #define elf_backend_can_gc_sections 1
1302 #define elf_backend_special_sections elf32_m68hc11_special_sections
1304 #define bfd_elf32_bfd_link_hash_table_create \
1305 m68hc11_elf_bfd_link_hash_table_create
1306 #define bfd_elf32_bfd_link_hash_table_free \
1307 m68hc11_elf_bfd_link_hash_table_free
1308 #define bfd_elf32_bfd_merge_private_bfd_data \
1309 _bfd_m68hc11_elf_merge_private_bfd_data
1310 #define bfd_elf32_bfd_set_private_flags _bfd_m68hc11_elf_set_private_flags
1311 #define bfd_elf32_bfd_print_private_bfd_data \
1312 _bfd_m68hc11_elf_print_private_bfd_data
1314 #include "elf32-target.h"