bfd/
[binutils.git] / bfd / elf32-m68hc11.c
blob0fee7dff05eb361da166cf09890b65651c605d4c
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 3 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,
22 MA 02110-1301, USA. */
24 #include "sysdep.h"
25 #include "bfd.h"
26 #include "bfdlink.h"
27 #include "libbfd.h"
28 #include "elf-bfd.h"
29 #include "elf32-m68hc1x.h"
30 #include "elf/m68hc11.h"
31 #include "opcode/m68hc11.h"
33 /* Relocation functions. */
34 static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
35 (bfd *, bfd_reloc_code_real_type);
36 static void m68hc11_info_to_howto_rel
37 (bfd *, arelent *, Elf_Internal_Rela *);
39 /* Trampoline generation. */
40 static bfd_boolean m68hc11_elf_size_one_stub
41 (struct bfd_hash_entry *gen_entry, void *in_arg);
42 static bfd_boolean m68hc11_elf_build_one_stub
43 (struct bfd_hash_entry *gen_entry, void *in_arg);
44 static struct bfd_link_hash_table* m68hc11_elf_bfd_link_hash_table_create
45 (bfd* abfd);
47 /* Linker relaxation. */
48 static bfd_boolean m68hc11_elf_relax_section
49 (bfd *, asection *, struct bfd_link_info *, bfd_boolean *);
50 static void m68hc11_elf_relax_delete_bytes
51 (bfd *, asection *, bfd_vma, int);
52 static void m68hc11_relax_group
53 (bfd *, asection *, bfd_byte *, unsigned, unsigned long, unsigned long);
54 static int compare_reloc (const void *, const void *);
56 /* Use REL instead of RELA to save space */
57 #define USE_REL 1
59 /* The Motorola 68HC11 microcontroller only addresses 64Kb but we also
60 support a memory bank switching mechanism similar to 68HC12.
61 We must handle 8 and 16-bit relocations. The 32-bit relocation
62 are used for debugging sections (DWARF2) to represent a virtual
63 address.
64 The 3-bit and 16-bit PC rel relocation is only used by 68HC12. */
65 static reloc_howto_type elf_m68hc11_howto_table[] = {
66 /* This reloc does nothing. */
67 HOWTO (R_M68HC11_NONE, /* type */
68 0, /* rightshift */
69 2, /* size (0 = byte, 1 = short, 2 = long) */
70 32, /* bitsize */
71 FALSE, /* pc_relative */
72 0, /* bitpos */
73 complain_overflow_dont,/* complain_on_overflow */
74 bfd_elf_generic_reloc, /* special_function */
75 "R_M68HC11_NONE", /* name */
76 FALSE, /* partial_inplace */
77 0, /* src_mask */
78 0, /* dst_mask */
79 FALSE), /* pcrel_offset */
81 /* A 8 bit absolute relocation */
82 HOWTO (R_M68HC11_8, /* type */
83 0, /* rightshift */
84 0, /* size (0 = byte, 1 = short, 2 = long) */
85 8, /* bitsize */
86 FALSE, /* pc_relative */
87 0, /* bitpos */
88 complain_overflow_bitfield, /* complain_on_overflow */
89 bfd_elf_generic_reloc, /* special_function */
90 "R_M68HC11_8", /* name */
91 FALSE, /* partial_inplace */
92 0x00ff, /* src_mask */
93 0x00ff, /* dst_mask */
94 FALSE), /* pcrel_offset */
96 /* A 8 bit absolute relocation (upper address) */
97 HOWTO (R_M68HC11_HI8, /* type */
98 8, /* rightshift */
99 0, /* size (0 = byte, 1 = short, 2 = long) */
100 8, /* bitsize */
101 FALSE, /* pc_relative */
102 0, /* bitpos */
103 complain_overflow_bitfield, /* complain_on_overflow */
104 bfd_elf_generic_reloc, /* special_function */
105 "R_M68HC11_HI8", /* name */
106 FALSE, /* partial_inplace */
107 0x00ff, /* src_mask */
108 0x00ff, /* dst_mask */
109 FALSE), /* pcrel_offset */
111 /* A 8 bit absolute relocation (upper address) */
112 HOWTO (R_M68HC11_LO8, /* type */
113 0, /* rightshift */
114 0, /* size (0 = byte, 1 = short, 2 = long) */
115 8, /* bitsize */
116 FALSE, /* pc_relative */
117 0, /* bitpos */
118 complain_overflow_dont, /* complain_on_overflow */
119 bfd_elf_generic_reloc, /* special_function */
120 "R_M68HC11_LO8", /* name */
121 FALSE, /* partial_inplace */
122 0x00ff, /* src_mask */
123 0x00ff, /* dst_mask */
124 FALSE), /* pcrel_offset */
126 /* A 8 bit PC-rel relocation */
127 HOWTO (R_M68HC11_PCREL_8, /* type */
128 0, /* rightshift */
129 0, /* size (0 = byte, 1 = short, 2 = long) */
130 8, /* bitsize */
131 TRUE, /* pc_relative */
132 0, /* bitpos */
133 complain_overflow_bitfield, /* complain_on_overflow */
134 bfd_elf_generic_reloc, /* special_function */
135 "R_M68HC11_PCREL_8", /* name */
136 FALSE, /* partial_inplace */
137 0x00ff, /* src_mask */
138 0x00ff, /* dst_mask */
139 TRUE), /* pcrel_offset */
141 /* A 16 bit absolute relocation */
142 HOWTO (R_M68HC11_16, /* type */
143 0, /* rightshift */
144 1, /* size (0 = byte, 1 = short, 2 = long) */
145 16, /* bitsize */
146 FALSE, /* pc_relative */
147 0, /* bitpos */
148 complain_overflow_dont /*bitfield */ , /* complain_on_overflow */
149 bfd_elf_generic_reloc, /* special_function */
150 "R_M68HC11_16", /* name */
151 FALSE, /* partial_inplace */
152 0xffff, /* src_mask */
153 0xffff, /* dst_mask */
154 FALSE), /* pcrel_offset */
156 /* A 32 bit absolute relocation. This one is never used for the
157 code relocation. It's used by gas for -gstabs generation. */
158 HOWTO (R_M68HC11_32, /* type */
159 0, /* rightshift */
160 2, /* size (0 = byte, 1 = short, 2 = long) */
161 32, /* bitsize */
162 FALSE, /* pc_relative */
163 0, /* bitpos */
164 complain_overflow_bitfield, /* complain_on_overflow */
165 bfd_elf_generic_reloc, /* special_function */
166 "R_M68HC11_32", /* name */
167 FALSE, /* partial_inplace */
168 0xffffffff, /* src_mask */
169 0xffffffff, /* dst_mask */
170 FALSE), /* pcrel_offset */
172 /* A 3 bit absolute relocation */
173 HOWTO (R_M68HC11_3B, /* type */
174 0, /* rightshift */
175 0, /* size (0 = byte, 1 = short, 2 = long) */
176 3, /* bitsize */
177 FALSE, /* pc_relative */
178 0, /* bitpos */
179 complain_overflow_bitfield, /* complain_on_overflow */
180 bfd_elf_generic_reloc, /* special_function */
181 "R_M68HC11_4B", /* name */
182 FALSE, /* partial_inplace */
183 0x003, /* src_mask */
184 0x003, /* dst_mask */
185 FALSE), /* pcrel_offset */
187 /* A 16 bit PC-rel relocation */
188 HOWTO (R_M68HC11_PCREL_16, /* type */
189 0, /* rightshift */
190 1, /* size (0 = byte, 1 = short, 2 = long) */
191 16, /* bitsize */
192 TRUE, /* pc_relative */
193 0, /* bitpos */
194 complain_overflow_dont, /* complain_on_overflow */
195 bfd_elf_generic_reloc, /* special_function */
196 "R_M68HC11_PCREL_16", /* name */
197 FALSE, /* partial_inplace */
198 0xffff, /* src_mask */
199 0xffff, /* dst_mask */
200 TRUE), /* pcrel_offset */
202 /* GNU extension to record C++ vtable hierarchy */
203 HOWTO (R_M68HC11_GNU_VTINHERIT, /* type */
204 0, /* rightshift */
205 1, /* size (0 = byte, 1 = short, 2 = long) */
206 0, /* bitsize */
207 FALSE, /* pc_relative */
208 0, /* bitpos */
209 complain_overflow_dont, /* complain_on_overflow */
210 NULL, /* special_function */
211 "R_M68HC11_GNU_VTINHERIT", /* name */
212 FALSE, /* partial_inplace */
213 0, /* src_mask */
214 0, /* dst_mask */
215 FALSE), /* pcrel_offset */
217 /* GNU extension to record C++ vtable member usage */
218 HOWTO (R_M68HC11_GNU_VTENTRY, /* type */
219 0, /* rightshift */
220 1, /* size (0 = byte, 1 = short, 2 = long) */
221 0, /* bitsize */
222 FALSE, /* pc_relative */
223 0, /* bitpos */
224 complain_overflow_dont, /* complain_on_overflow */
225 _bfd_elf_rel_vtable_reloc_fn, /* special_function */
226 "R_M68HC11_GNU_VTENTRY", /* name */
227 FALSE, /* partial_inplace */
228 0, /* src_mask */
229 0, /* dst_mask */
230 FALSE), /* pcrel_offset */
232 /* A 24 bit relocation */
233 HOWTO (R_M68HC11_24, /* type */
234 0, /* rightshift */
235 1, /* size (0 = byte, 1 = short, 2 = long) */
236 24, /* bitsize */
237 FALSE, /* pc_relative */
238 0, /* bitpos */
239 complain_overflow_bitfield, /* complain_on_overflow */
240 bfd_elf_generic_reloc, /* special_function */
241 "R_M68HC11_24", /* name */
242 FALSE, /* partial_inplace */
243 0xffffff, /* src_mask */
244 0xffffff, /* dst_mask */
245 FALSE), /* pcrel_offset */
247 /* A 16-bit low relocation */
248 HOWTO (R_M68HC11_LO16, /* type */
249 0, /* rightshift */
250 1, /* size (0 = byte, 1 = short, 2 = long) */
251 16, /* bitsize */
252 FALSE, /* pc_relative */
253 0, /* bitpos */
254 complain_overflow_bitfield, /* complain_on_overflow */
255 bfd_elf_generic_reloc, /* special_function */
256 "R_M68HC11_LO16", /* name */
257 FALSE, /* partial_inplace */
258 0xffff, /* src_mask */
259 0xffff, /* dst_mask */
260 FALSE), /* pcrel_offset */
262 /* A page relocation */
263 HOWTO (R_M68HC11_PAGE, /* type */
264 0, /* rightshift */
265 0, /* size (0 = byte, 1 = short, 2 = long) */
266 8, /* bitsize */
267 FALSE, /* pc_relative */
268 0, /* bitpos */
269 complain_overflow_bitfield, /* complain_on_overflow */
270 bfd_elf_generic_reloc, /* special_function */
271 "R_M68HC11_PAGE", /* name */
272 FALSE, /* partial_inplace */
273 0x00ff, /* src_mask */
274 0x00ff, /* dst_mask */
275 FALSE), /* pcrel_offset */
277 EMPTY_HOWTO (14),
278 EMPTY_HOWTO (15),
279 EMPTY_HOWTO (16),
280 EMPTY_HOWTO (17),
281 EMPTY_HOWTO (18),
282 EMPTY_HOWTO (19),
284 /* Mark beginning of a jump instruction (any form). */
285 HOWTO (R_M68HC11_RL_JUMP, /* type */
286 0, /* rightshift */
287 1, /* size (0 = byte, 1 = short, 2 = long) */
288 0, /* bitsize */
289 FALSE, /* pc_relative */
290 0, /* bitpos */
291 complain_overflow_dont, /* complain_on_overflow */
292 m68hc11_elf_ignore_reloc, /* special_function */
293 "R_M68HC11_RL_JUMP", /* name */
294 TRUE, /* partial_inplace */
295 0, /* src_mask */
296 0, /* dst_mask */
297 TRUE), /* pcrel_offset */
299 /* Mark beginning of Gcc relaxation group instruction. */
300 HOWTO (R_M68HC11_RL_GROUP, /* type */
301 0, /* rightshift */
302 1, /* size (0 = byte, 1 = short, 2 = long) */
303 0, /* bitsize */
304 FALSE, /* pc_relative */
305 0, /* bitpos */
306 complain_overflow_dont, /* complain_on_overflow */
307 m68hc11_elf_ignore_reloc, /* special_function */
308 "R_M68HC11_RL_GROUP", /* name */
309 TRUE, /* partial_inplace */
310 0, /* src_mask */
311 0, /* dst_mask */
312 TRUE), /* pcrel_offset */
315 /* Map BFD reloc types to M68HC11 ELF reloc types. */
317 struct m68hc11_reloc_map
319 bfd_reloc_code_real_type bfd_reloc_val;
320 unsigned char elf_reloc_val;
323 static const struct m68hc11_reloc_map m68hc11_reloc_map[] = {
324 {BFD_RELOC_NONE, R_M68HC11_NONE,},
325 {BFD_RELOC_8, R_M68HC11_8},
326 {BFD_RELOC_M68HC11_HI8, R_M68HC11_HI8},
327 {BFD_RELOC_M68HC11_LO8, R_M68HC11_LO8},
328 {BFD_RELOC_8_PCREL, R_M68HC11_PCREL_8},
329 {BFD_RELOC_16_PCREL, R_M68HC11_PCREL_16},
330 {BFD_RELOC_16, R_M68HC11_16},
331 {BFD_RELOC_32, R_M68HC11_32},
332 {BFD_RELOC_M68HC11_3B, R_M68HC11_3B},
334 {BFD_RELOC_VTABLE_INHERIT, R_M68HC11_GNU_VTINHERIT},
335 {BFD_RELOC_VTABLE_ENTRY, R_M68HC11_GNU_VTENTRY},
337 {BFD_RELOC_M68HC11_LO16, R_M68HC11_LO16},
338 {BFD_RELOC_M68HC11_PAGE, R_M68HC11_PAGE},
339 {BFD_RELOC_M68HC11_24, R_M68HC11_24},
341 {BFD_RELOC_M68HC11_RL_JUMP, R_M68HC11_RL_JUMP},
342 {BFD_RELOC_M68HC11_RL_GROUP, R_M68HC11_RL_GROUP},
345 static reloc_howto_type *
346 bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
347 bfd_reloc_code_real_type code)
349 unsigned int i;
351 for (i = 0;
352 i < sizeof (m68hc11_reloc_map) / sizeof (struct m68hc11_reloc_map);
353 i++)
355 if (m68hc11_reloc_map[i].bfd_reloc_val == code)
356 return &elf_m68hc11_howto_table[m68hc11_reloc_map[i].elf_reloc_val];
359 return NULL;
362 static reloc_howto_type *
363 bfd_elf32_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
364 const char *r_name)
366 unsigned int i;
368 for (i = 0;
369 i < (sizeof (elf_m68hc11_howto_table)
370 / sizeof (elf_m68hc11_howto_table[0]));
371 i++)
372 if (elf_m68hc11_howto_table[i].name != NULL
373 && strcasecmp (elf_m68hc11_howto_table[i].name, r_name) == 0)
374 return &elf_m68hc11_howto_table[i];
376 return NULL;
379 /* Set the howto pointer for an M68HC11 ELF reloc. */
381 static void
382 m68hc11_info_to_howto_rel (bfd *abfd ATTRIBUTE_UNUSED,
383 arelent *cache_ptr, Elf_Internal_Rela *dst)
385 unsigned int r_type;
387 r_type = ELF32_R_TYPE (dst->r_info);
388 BFD_ASSERT (r_type < (unsigned int) R_M68HC11_max);
389 cache_ptr->howto = &elf_m68hc11_howto_table[r_type];
393 /* Far trampoline generation. */
395 /* Build a 68HC11 trampoline stub. */
396 static bfd_boolean
397 m68hc11_elf_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
399 struct elf32_m68hc11_stub_hash_entry *stub_entry;
400 struct bfd_link_info *info;
401 struct m68hc11_elf_link_hash_table *htab;
402 asection *stub_sec;
403 bfd *stub_bfd;
404 bfd_byte *loc;
405 bfd_vma sym_value, phys_page, phys_addr;
407 /* Massage our args to the form they really have. */
408 stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
409 info = (struct bfd_link_info *) in_arg;
411 htab = m68hc11_elf_hash_table (info);
413 stub_sec = stub_entry->stub_sec;
415 /* Make a note of the offset within the stubs for this entry. */
416 stub_entry->stub_offset = stub_sec->size;
417 stub_sec->size += 10;
418 loc = stub_sec->contents + stub_entry->stub_offset;
420 stub_bfd = stub_sec->owner;
422 /* Create the trampoline call stub:
424 pshb
425 ldab #%page(symbol)
426 ldy #%addr(symbol)
427 jmp __trampoline
430 sym_value = (stub_entry->target_value
431 + stub_entry->target_section->output_offset
432 + stub_entry->target_section->output_section->vma);
433 phys_addr = m68hc11_phys_addr (&htab->pinfo, sym_value);
434 phys_page = m68hc11_phys_page (&htab->pinfo, sym_value);
436 /* pshb; ldab #%page(sym) */
437 bfd_put_8 (stub_bfd, 0x37, loc);
438 bfd_put_8 (stub_bfd, 0xC6, loc + 1);
439 bfd_put_8 (stub_bfd, phys_page, loc + 2);
440 loc += 3;
442 /* ldy #%addr(sym) */
443 bfd_put_8 (stub_bfd, 0x18, loc);
444 bfd_put_8 (stub_bfd, 0xCE, loc + 1);
445 bfd_put_16 (stub_bfd, phys_addr, loc + 2);
446 loc += 4;
448 /* jmp __trampoline */
449 bfd_put_8 (stub_bfd, 0x7E, loc);
450 bfd_put_16 (stub_bfd, htab->pinfo.trampoline_addr, loc + 1);
452 return TRUE;
455 /* As above, but don't actually build the stub. Just bump offset so
456 we know stub section sizes. */
458 static bfd_boolean
459 m68hc11_elf_size_one_stub (struct bfd_hash_entry *gen_entry,
460 void *in_arg ATTRIBUTE_UNUSED)
462 struct elf32_m68hc11_stub_hash_entry *stub_entry;
464 /* Massage our args to the form they really have. */
465 stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
467 stub_entry->stub_sec->size += 10;
468 return TRUE;
471 /* Create a 68HC11 ELF linker hash table. */
473 static struct bfd_link_hash_table *
474 m68hc11_elf_bfd_link_hash_table_create (bfd *abfd)
476 struct m68hc11_elf_link_hash_table *ret;
478 ret = m68hc11_elf_hash_table_create (abfd);
479 if (ret == (struct m68hc11_elf_link_hash_table *) NULL)
480 return NULL;
482 ret->size_one_stub = m68hc11_elf_size_one_stub;
483 ret->build_one_stub = m68hc11_elf_build_one_stub;
485 return &ret->root.root;
489 /* 68HC11 Linker Relaxation. */
491 struct m68hc11_direct_relax
493 const char *name;
494 unsigned char code;
495 unsigned char direct_code;
496 } m68hc11_direct_relax_table[] = {
497 { "adca", 0xB9, 0x99 },
498 { "adcb", 0xF9, 0xD9 },
499 { "adda", 0xBB, 0x9B },
500 { "addb", 0xFB, 0xDB },
501 { "addd", 0xF3, 0xD3 },
502 { "anda", 0xB4, 0x94 },
503 { "andb", 0xF4, 0xD4 },
504 { "cmpa", 0xB1, 0x91 },
505 { "cmpb", 0xF1, 0xD1 },
506 { "cpd", 0xB3, 0x93 },
507 { "cpxy", 0xBC, 0x9C },
508 /* { "cpy", 0xBC, 0x9C }, */
509 { "eora", 0xB8, 0x98 },
510 { "eorb", 0xF8, 0xD8 },
511 { "jsr", 0xBD, 0x9D },
512 { "ldaa", 0xB6, 0x96 },
513 { "ldab", 0xF6, 0xD6 },
514 { "ldd", 0xFC, 0xDC },
515 { "lds", 0xBE, 0x9E },
516 { "ldxy", 0xFE, 0xDE },
517 /* { "ldy", 0xFE, 0xDE },*/
518 { "oraa", 0xBA, 0x9A },
519 { "orab", 0xFA, 0xDA },
520 { "sbca", 0xB2, 0x92 },
521 { "sbcb", 0xF2, 0xD2 },
522 { "staa", 0xB7, 0x97 },
523 { "stab", 0xF7, 0xD7 },
524 { "std", 0xFD, 0xDD },
525 { "sts", 0xBF, 0x9F },
526 { "stxy", 0xFF, 0xDF },
527 /* { "sty", 0xFF, 0xDF },*/
528 { "suba", 0xB0, 0x90 },
529 { "subb", 0xF0, 0xD0 },
530 { "subd", 0xB3, 0x93 },
531 { 0, 0, 0 }
534 static struct m68hc11_direct_relax *
535 find_relaxable_insn (unsigned char code)
537 int i;
539 for (i = 0; m68hc11_direct_relax_table[i].name; i++)
540 if (m68hc11_direct_relax_table[i].code == code)
541 return &m68hc11_direct_relax_table[i];
543 return 0;
546 static int
547 compare_reloc (const void *e1, const void *e2)
549 const Elf_Internal_Rela *i1 = (const Elf_Internal_Rela *) e1;
550 const Elf_Internal_Rela *i2 = (const Elf_Internal_Rela *) e2;
552 if (i1->r_offset == i2->r_offset)
553 return 0;
554 else
555 return i1->r_offset < i2->r_offset ? -1 : 1;
558 #define M6811_OP_LDX_IMMEDIATE (0xCE)
560 static void
561 m68hc11_relax_group (bfd *abfd, asection *sec, bfd_byte *contents,
562 unsigned value, unsigned long offset,
563 unsigned long end_group)
565 unsigned char code;
566 unsigned long start_offset;
567 unsigned long ldx_offset = offset;
568 unsigned long ldx_size;
569 int can_delete_ldx;
570 int relax_ldy = 0;
572 /* First instruction of the relax group must be a
573 LDX #value or LDY #value. If this is not the case,
574 ignore the relax group. */
575 code = bfd_get_8 (abfd, contents + offset);
576 if (code == 0x18)
578 relax_ldy++;
579 offset++;
580 code = bfd_get_8 (abfd, contents + offset);
582 ldx_size = offset - ldx_offset + 3;
583 offset += 3;
584 if (code != M6811_OP_LDX_IMMEDIATE || offset >= end_group)
585 return;
588 /* We can remove the LDX/LDY only when all bset/brclr instructions
589 of the relax group have been converted to use direct addressing
590 mode. */
591 can_delete_ldx = 1;
592 while (offset < end_group)
594 unsigned isize;
595 unsigned new_value;
596 int bset_use_y;
598 bset_use_y = 0;
599 start_offset = offset;
600 code = bfd_get_8 (abfd, contents + offset);
601 if (code == 0x18)
603 bset_use_y++;
604 offset++;
605 code = bfd_get_8 (abfd, contents + offset);
608 /* Check the instruction and translate to use direct addressing mode. */
609 switch (code)
611 /* bset */
612 case 0x1C:
613 code = 0x14;
614 isize = 3;
615 break;
617 /* brclr */
618 case 0x1F:
619 code = 0x13;
620 isize = 4;
621 break;
623 /* brset */
624 case 0x1E:
625 code = 0x12;
626 isize = 4;
627 break;
629 /* bclr */
630 case 0x1D:
631 code = 0x15;
632 isize = 3;
633 break;
635 /* This instruction is not recognized and we are not
636 at end of the relax group. Ignore and don't remove
637 the first LDX (we don't know what it is used for...). */
638 default:
639 return;
641 new_value = (unsigned) bfd_get_8 (abfd, contents + offset + 1);
642 new_value += value;
643 if ((new_value & 0xff00) == 0 && bset_use_y == relax_ldy)
645 bfd_put_8 (abfd, code, contents + offset);
646 bfd_put_8 (abfd, new_value, contents + offset + 1);
647 if (start_offset != offset)
649 m68hc11_elf_relax_delete_bytes (abfd, sec, start_offset,
650 offset - start_offset);
651 end_group--;
654 else
656 can_delete_ldx = 0;
658 offset = start_offset + isize;
660 if (can_delete_ldx)
662 /* Remove the move instruction (3 or 4 bytes win). */
663 m68hc11_elf_relax_delete_bytes (abfd, sec, ldx_offset, ldx_size);
667 /* This function handles relaxing for the 68HC11.
670 and somewhat more difficult to support. */
672 static bfd_boolean
673 m68hc11_elf_relax_section (bfd *abfd, asection *sec,
674 struct bfd_link_info *link_info, bfd_boolean *again)
676 Elf_Internal_Shdr *symtab_hdr;
677 Elf_Internal_Shdr *shndx_hdr;
678 Elf_Internal_Rela *internal_relocs;
679 Elf_Internal_Rela *free_relocs = NULL;
680 Elf_Internal_Rela *irel, *irelend;
681 bfd_byte *contents = NULL;
682 bfd_byte *free_contents = NULL;
683 Elf32_External_Sym *free_extsyms = NULL;
684 Elf_Internal_Rela *prev_insn_branch = NULL;
685 Elf_Internal_Rela *prev_insn_group = NULL;
686 unsigned insn_group_value = 0;
687 Elf_Internal_Sym *isymbuf = NULL;
689 /* Assume nothing changes. */
690 *again = FALSE;
692 /* We don't have to do anything for a relocatable link, if
693 this section does not have relocs, or if this is not a
694 code section. */
695 if (link_info->relocatable
696 || (sec->flags & SEC_RELOC) == 0
697 || sec->reloc_count == 0
698 || (sec->flags & SEC_CODE) == 0)
699 return TRUE;
701 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
702 shndx_hdr = &elf_tdata (abfd)->symtab_shndx_hdr;
704 /* Get a copy of the native relocations. */
705 internal_relocs = (_bfd_elf_link_read_relocs
706 (abfd, sec, (PTR) NULL, (Elf_Internal_Rela *) NULL,
707 link_info->keep_memory));
708 if (internal_relocs == NULL)
709 goto error_return;
710 if (! link_info->keep_memory)
711 free_relocs = internal_relocs;
713 /* Checking for branch relaxation relies on the relocations to
714 be sorted on 'r_offset'. This is not guaranteed so we must sort. */
715 qsort (internal_relocs, sec->reloc_count, sizeof (Elf_Internal_Rela),
716 compare_reloc);
718 /* Walk through them looking for relaxing opportunities. */
719 irelend = internal_relocs + sec->reloc_count;
720 for (irel = internal_relocs; irel < irelend; irel++)
722 bfd_vma symval;
723 bfd_vma value;
724 Elf_Internal_Sym *isym;
725 asection *sym_sec;
726 int is_far = 0;
728 /* If this isn't something that can be relaxed, then ignore
729 this reloc. */
730 if (ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_16
731 && ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_RL_JUMP
732 && ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_RL_GROUP)
734 prev_insn_branch = 0;
735 prev_insn_group = 0;
736 continue;
739 /* Get the section contents if we haven't done so already. */
740 if (contents == NULL)
742 /* Get cached copy if it exists. */
743 if (elf_section_data (sec)->this_hdr.contents != NULL)
744 contents = elf_section_data (sec)->this_hdr.contents;
745 else
747 /* Go get them off disk. */
748 if (!bfd_malloc_and_get_section (abfd, sec, &contents))
749 goto error_return;
753 /* Try to eliminate an unconditional 8 bit pc-relative branch
754 which immediately follows a conditional 8 bit pc-relative
755 branch around the unconditional branch.
757 original: new:
758 bCC lab1 bCC' lab2
759 bra lab2
760 lab1: lab1:
762 This happens when the bCC can't reach lab2 at assembly time,
763 but due to other relaxations it can reach at link time. */
764 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_RL_JUMP)
766 Elf_Internal_Rela *nrel;
767 unsigned char code;
768 unsigned char roffset;
770 prev_insn_branch = 0;
771 prev_insn_group = 0;
773 /* Do nothing if this reloc is the last byte in the section. */
774 if (irel->r_offset + 2 >= sec->size)
775 continue;
777 /* See if the next instruction is an unconditional pc-relative
778 branch, more often than not this test will fail, so we
779 test it first to speed things up. */
780 code = bfd_get_8 (abfd, contents + irel->r_offset + 2);
781 if (code != 0x7e)
782 continue;
784 /* Also make sure the next relocation applies to the next
785 instruction and that it's a pc-relative 8 bit branch. */
786 nrel = irel + 1;
787 if (nrel == irelend
788 || irel->r_offset + 3 != nrel->r_offset
789 || ELF32_R_TYPE (nrel->r_info) != (int) R_M68HC11_16)
790 continue;
792 /* Make sure our destination immediately follows the
793 unconditional branch. */
794 roffset = bfd_get_8 (abfd, contents + irel->r_offset + 1);
795 if (roffset != 3)
796 continue;
798 prev_insn_branch = irel;
799 prev_insn_group = 0;
800 continue;
803 /* Read this BFD's symbols if we haven't done so already. */
804 if (isymbuf == NULL && symtab_hdr->sh_info != 0)
806 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
807 if (isymbuf == NULL)
808 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
809 symtab_hdr->sh_info, 0,
810 NULL, NULL, NULL);
811 if (isymbuf == NULL)
812 goto error_return;
815 /* Get the value of the symbol referred to by the reloc. */
816 if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
818 /* A local symbol. */
819 isym = isymbuf + ELF32_R_SYM (irel->r_info);
820 is_far = isym->st_other & STO_M68HC12_FAR;
821 sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
822 symval = (isym->st_value
823 + sym_sec->output_section->vma
824 + sym_sec->output_offset);
826 else
828 unsigned long indx;
829 struct elf_link_hash_entry *h;
831 /* An external symbol. */
832 indx = ELF32_R_SYM (irel->r_info) - symtab_hdr->sh_info;
833 h = elf_sym_hashes (abfd)[indx];
834 BFD_ASSERT (h != NULL);
835 if (h->root.type != bfd_link_hash_defined
836 && h->root.type != bfd_link_hash_defweak)
838 /* This appears to be a reference to an undefined
839 symbol. Just ignore it--it will be caught by the
840 regular reloc processing. */
841 prev_insn_branch = 0;
842 prev_insn_group = 0;
843 continue;
846 is_far = h->other & STO_M68HC12_FAR;
847 isym = 0;
848 sym_sec = h->root.u.def.section;
849 symval = (h->root.u.def.value
850 + sym_sec->output_section->vma
851 + sym_sec->output_offset);
854 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_RL_GROUP)
856 prev_insn_branch = 0;
857 prev_insn_group = 0;
859 /* Do nothing if this reloc is the last byte in the section. */
860 if (irel->r_offset == sec->size)
861 continue;
863 prev_insn_group = irel;
864 insn_group_value = isym->st_value;
865 continue;
868 /* When we relax some bytes, the size of our section changes.
869 This affects the layout of next input sections that go in our
870 output section. When the symbol is part of another section that
871 will go in the same output section as the current one, it's
872 final address may now be incorrect (too far). We must let the
873 linker re-compute all section offsets before processing this
874 reloc. Code example:
876 Initial Final
877 .sect .text section size = 6 section size = 4
878 jmp foo
879 jmp bar
880 .sect .text.foo_bar output_offset = 6 output_offset = 4
881 foo: rts
882 bar: rts
884 If we process the reloc now, the jmp bar is replaced by a
885 relative branch to the initial bar address (output_offset 6). */
886 if (*again && sym_sec != sec
887 && sym_sec->output_section == sec->output_section)
889 prev_insn_group = 0;
890 prev_insn_branch = 0;
891 continue;
894 value = symval;
895 /* Try to turn a far branch to a near branch. */
896 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_16
897 && prev_insn_branch)
899 bfd_vma offset;
900 unsigned char code;
902 offset = value - (prev_insn_branch->r_offset
903 + sec->output_section->vma
904 + sec->output_offset + 2);
906 /* If the offset is still out of -128..+127 range,
907 leave that far branch unchanged. */
908 if ((offset & 0xff80) != 0 && (offset & 0xff80) != 0xff80)
910 prev_insn_branch = 0;
911 continue;
914 /* Shrink the branch. */
915 code = bfd_get_8 (abfd, contents + prev_insn_branch->r_offset);
916 if (code == 0x7e)
918 code = 0x20;
919 bfd_put_8 (abfd, code, contents + prev_insn_branch->r_offset);
920 bfd_put_8 (abfd, 0xff,
921 contents + prev_insn_branch->r_offset + 1);
922 irel->r_offset = prev_insn_branch->r_offset + 1;
923 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
924 R_M68HC11_PCREL_8);
925 m68hc11_elf_relax_delete_bytes (abfd, sec,
926 irel->r_offset + 1, 1);
928 else
930 code ^= 0x1;
931 bfd_put_8 (abfd, code, contents + prev_insn_branch->r_offset);
932 bfd_put_8 (abfd, 0xff,
933 contents + prev_insn_branch->r_offset + 1);
934 irel->r_offset = prev_insn_branch->r_offset + 1;
935 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
936 R_M68HC11_PCREL_8);
937 m68hc11_elf_relax_delete_bytes (abfd, sec,
938 irel->r_offset + 1, 3);
940 prev_insn_branch = 0;
941 *again = TRUE;
944 /* Try to turn a 16 bit address into a 8 bit page0 address. */
945 else if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_16
946 && (value & 0xff00) == 0)
948 unsigned char code;
949 unsigned short offset;
950 struct m68hc11_direct_relax *rinfo;
952 prev_insn_branch = 0;
953 offset = bfd_get_16 (abfd, contents + irel->r_offset);
954 offset += value;
955 if ((offset & 0xff00) != 0)
957 prev_insn_group = 0;
958 continue;
961 if (prev_insn_group)
963 unsigned long old_sec_size = sec->size;
965 /* Note that we've changed the relocation contents, etc. */
966 elf_section_data (sec)->relocs = internal_relocs;
967 free_relocs = NULL;
969 elf_section_data (sec)->this_hdr.contents = contents;
970 free_contents = NULL;
972 symtab_hdr->contents = (bfd_byte *) isymbuf;
973 free_extsyms = NULL;
975 m68hc11_relax_group (abfd, sec, contents, offset,
976 prev_insn_group->r_offset,
977 insn_group_value);
978 irel = prev_insn_group;
979 prev_insn_group = 0;
980 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
981 R_M68HC11_NONE);
982 if (sec->size != old_sec_size)
983 *again = TRUE;
984 continue;
987 /* Get the opcode. */
988 code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
989 rinfo = find_relaxable_insn (code);
990 if (rinfo == 0)
992 prev_insn_group = 0;
993 continue;
996 /* Note that we've changed the relocation contents, etc. */
997 elf_section_data (sec)->relocs = internal_relocs;
998 free_relocs = NULL;
1000 elf_section_data (sec)->this_hdr.contents = contents;
1001 free_contents = NULL;
1003 symtab_hdr->contents = (bfd_byte *) isymbuf;
1004 free_extsyms = NULL;
1006 /* Fix the opcode. */
1007 /* printf ("A relaxable case : 0x%02x (%s)\n",
1008 code, rinfo->name); */
1009 bfd_put_8 (abfd, rinfo->direct_code,
1010 contents + irel->r_offset - 1);
1012 /* Delete one byte of data (upper byte of address). */
1013 m68hc11_elf_relax_delete_bytes (abfd, sec, irel->r_offset, 1);
1015 /* Fix the relocation's type. */
1016 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1017 R_M68HC11_8);
1019 /* That will change things, so, we should relax again. */
1020 *again = TRUE;
1022 else if (ELF32_R_TYPE (irel->r_info) == R_M68HC11_16 && !is_far)
1024 unsigned char code;
1025 bfd_vma offset;
1027 prev_insn_branch = 0;
1028 code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
1029 if (code == 0x7e || code == 0xbd)
1031 offset = value - (irel->r_offset
1032 + sec->output_section->vma
1033 + sec->output_offset + 1);
1034 offset += bfd_get_16 (abfd, contents + irel->r_offset);
1036 /* If the offset is still out of -128..+127 range,
1037 leave that far branch unchanged. */
1038 if ((offset & 0xff80) == 0 || (offset & 0xff80) == 0xff80)
1041 /* Note that we've changed the relocation contents, etc. */
1042 elf_section_data (sec)->relocs = internal_relocs;
1043 free_relocs = NULL;
1045 elf_section_data (sec)->this_hdr.contents = contents;
1046 free_contents = NULL;
1048 symtab_hdr->contents = (bfd_byte *) isymbuf;
1049 free_extsyms = NULL;
1051 /* Shrink the branch. */
1052 code = (code == 0x7e) ? 0x20 : 0x8d;
1053 bfd_put_8 (abfd, code,
1054 contents + irel->r_offset - 1);
1055 bfd_put_8 (abfd, 0xff,
1056 contents + irel->r_offset);
1057 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1058 R_M68HC11_PCREL_8);
1059 m68hc11_elf_relax_delete_bytes (abfd, sec,
1060 irel->r_offset + 1, 1);
1061 /* That will change things, so, we should relax again. */
1062 *again = TRUE;
1066 prev_insn_branch = 0;
1067 prev_insn_group = 0;
1070 if (free_relocs != NULL)
1072 free (free_relocs);
1073 free_relocs = NULL;
1076 if (free_contents != NULL)
1078 if (! link_info->keep_memory)
1079 free (free_contents);
1080 else
1082 /* Cache the section contents for elf_link_input_bfd. */
1083 elf_section_data (sec)->this_hdr.contents = contents;
1085 free_contents = NULL;
1088 if (free_extsyms != NULL)
1090 if (! link_info->keep_memory)
1091 free (free_extsyms);
1092 else
1094 /* Cache the symbols for elf_link_input_bfd. */
1095 symtab_hdr->contents = (unsigned char *) isymbuf;
1097 free_extsyms = NULL;
1100 return TRUE;
1102 error_return:
1103 if (free_relocs != NULL)
1104 free (free_relocs);
1105 if (free_contents != NULL)
1106 free (free_contents);
1107 if (free_extsyms != NULL)
1108 free (free_extsyms);
1109 return FALSE;
1112 /* Delete some bytes from a section while relaxing. */
1114 static void
1115 m68hc11_elf_relax_delete_bytes (bfd *abfd, asection *sec,
1116 bfd_vma addr, int count)
1118 Elf_Internal_Shdr *symtab_hdr;
1119 unsigned int sec_shndx;
1120 bfd_byte *contents;
1121 Elf_Internal_Rela *irel, *irelend;
1122 bfd_vma toaddr;
1123 Elf_Internal_Sym *isymbuf, *isym, *isymend;
1124 struct elf_link_hash_entry **sym_hashes;
1125 struct elf_link_hash_entry **end_hashes;
1126 unsigned int symcount;
1128 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1129 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
1131 sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
1133 contents = elf_section_data (sec)->this_hdr.contents;
1135 toaddr = sec->size;
1137 irel = elf_section_data (sec)->relocs;
1138 irelend = irel + sec->reloc_count;
1140 /* Actually delete the bytes. */
1141 memmove (contents + addr, contents + addr + count,
1142 (size_t) (toaddr - addr - count));
1144 sec->size -= count;
1146 /* Adjust all the relocs. */
1147 for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
1149 unsigned char code;
1150 unsigned char offset;
1151 unsigned short raddr;
1152 unsigned long old_offset;
1153 int branch_pos;
1155 old_offset = irel->r_offset;
1157 /* See if this reloc was for the bytes we have deleted, in which
1158 case we no longer care about it. Don't delete relocs which
1159 represent addresses, though. */
1160 if (ELF32_R_TYPE (irel->r_info) != R_M68HC11_RL_JUMP
1161 && irel->r_offset >= addr && irel->r_offset < addr + count)
1162 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1163 R_M68HC11_NONE);
1165 if (ELF32_R_TYPE (irel->r_info) == R_M68HC11_NONE)
1166 continue;
1168 /* Get the new reloc address. */
1169 if ((irel->r_offset > addr
1170 && irel->r_offset < toaddr))
1171 irel->r_offset -= count;
1173 /* If this is a PC relative reloc, see if the range it covers
1174 includes the bytes we have deleted. */
1175 switch (ELF32_R_TYPE (irel->r_info))
1177 default:
1178 break;
1180 case R_M68HC11_RL_JUMP:
1181 code = bfd_get_8 (abfd, contents + irel->r_offset);
1182 switch (code)
1184 /* jsr and jmp instruction are also marked with RL_JUMP
1185 relocs but no adjustment must be made. */
1186 case 0x7e:
1187 case 0x9d:
1188 case 0xbd:
1189 continue;
1191 case 0x12:
1192 case 0x13:
1193 branch_pos = 3;
1194 raddr = 4;
1196 /* Special case when we translate a brclr N,y into brclr *<addr>
1197 In this case, the 0x18 page2 prefix is removed.
1198 The reloc offset is not modified but the instruction
1199 size is reduced by 1. */
1200 if (old_offset == addr)
1201 raddr++;
1202 break;
1204 case 0x1e:
1205 case 0x1f:
1206 branch_pos = 3;
1207 raddr = 4;
1208 break;
1210 case 0x18:
1211 branch_pos = 4;
1212 raddr = 5;
1213 break;
1215 default:
1216 branch_pos = 1;
1217 raddr = 2;
1218 break;
1220 offset = bfd_get_8 (abfd, contents + irel->r_offset + branch_pos);
1221 raddr += old_offset;
1222 raddr += ((unsigned short) offset | ((offset & 0x80) ? 0xff00 : 0));
1223 if (irel->r_offset < addr && raddr > addr)
1225 offset -= count;
1226 bfd_put_8 (abfd, offset, contents + irel->r_offset + branch_pos);
1228 else if (irel->r_offset >= addr && raddr <= addr)
1230 offset += count;
1231 bfd_put_8 (abfd, offset, contents + irel->r_offset + branch_pos);
1233 else
1235 /*printf ("Not adjusted 0x%04x [0x%4x 0x%4x]\n", raddr,
1236 irel->r_offset, addr);*/
1239 break;
1243 /* Adjust the local symbols defined in this section. */
1244 isymend = isymbuf + symtab_hdr->sh_info;
1245 for (isym = isymbuf; isym < isymend; isym++)
1247 if (isym->st_shndx == sec_shndx
1248 && isym->st_value > addr
1249 && isym->st_value <= toaddr)
1250 isym->st_value -= count;
1253 /* Now adjust the global symbols defined in this section. */
1254 symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
1255 - symtab_hdr->sh_info);
1256 sym_hashes = elf_sym_hashes (abfd);
1257 end_hashes = sym_hashes + symcount;
1258 for (; sym_hashes < end_hashes; sym_hashes++)
1260 struct elf_link_hash_entry *sym_hash = *sym_hashes;
1261 if ((sym_hash->root.type == bfd_link_hash_defined
1262 || sym_hash->root.type == bfd_link_hash_defweak)
1263 && sym_hash->root.u.def.section == sec
1264 && sym_hash->root.u.def.value > addr
1265 && sym_hash->root.u.def.value <= toaddr)
1267 sym_hash->root.u.def.value -= count;
1272 /* Specific sections:
1273 - The .page0 is a data section that is mapped in [0x0000..0x00FF].
1274 Page0 accesses are faster on the M68HC11. Soft registers used by GCC-m6811
1275 are located in .page0.
1276 - The .vectors is the section that represents the interrupt
1277 vectors. */
1278 static const struct bfd_elf_special_section elf32_m68hc11_special_sections[] =
1280 { STRING_COMMA_LEN (".eeprom"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
1281 { STRING_COMMA_LEN (".page0"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
1282 { STRING_COMMA_LEN (".softregs"), 0, SHT_NOBITS, SHF_ALLOC + SHF_WRITE },
1283 { STRING_COMMA_LEN (".vectors"), 0, SHT_PROGBITS, SHF_ALLOC },
1284 { NULL, 0, 0, 0, 0 }
1287 #define ELF_ARCH bfd_arch_m68hc11
1288 #define ELF_MACHINE_CODE EM_68HC11
1289 #define ELF_MAXPAGESIZE 0x1000
1291 #define TARGET_BIG_SYM bfd_elf32_m68hc11_vec
1292 #define TARGET_BIG_NAME "elf32-m68hc11"
1294 #define elf_info_to_howto 0
1295 #define elf_info_to_howto_rel m68hc11_info_to_howto_rel
1296 #define bfd_elf32_bfd_relax_section m68hc11_elf_relax_section
1297 #define elf_backend_check_relocs elf32_m68hc11_check_relocs
1298 #define elf_backend_relocate_section elf32_m68hc11_relocate_section
1299 #define elf_backend_add_symbol_hook elf32_m68hc11_add_symbol_hook
1300 #define elf_backend_object_p 0
1301 #define elf_backend_final_write_processing 0
1302 #define elf_backend_can_gc_sections 1
1303 #define elf_backend_special_sections elf32_m68hc11_special_sections
1305 #define bfd_elf32_bfd_link_hash_table_create \
1306 m68hc11_elf_bfd_link_hash_table_create
1307 #define bfd_elf32_bfd_link_hash_table_free \
1308 m68hc11_elf_bfd_link_hash_table_free
1309 #define bfd_elf32_bfd_merge_private_bfd_data \
1310 _bfd_m68hc11_elf_merge_private_bfd_data
1311 #define bfd_elf32_bfd_set_private_flags _bfd_m68hc11_elf_set_private_flags
1312 #define bfd_elf32_bfd_print_private_bfd_data \
1313 _bfd_m68hc11_elf_print_private_bfd_data
1315 #include "elf32-target.h"