2010-04-05 Kai Tietz <kai.tietz@onevision.com>
[binutils.git] / bfd / elf32-m68hc11.c
blob5e5b890d2893d639528fcdb01d0da92b2714575d
1 /* Motorola 68HC11-specific support for 32-bit ELF
2 Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2010
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);
412 if (htab == NULL)
413 return FALSE;
415 stub_sec = stub_entry->stub_sec;
417 /* Make a note of the offset within the stubs for this entry. */
418 stub_entry->stub_offset = stub_sec->size;
419 stub_sec->size += 10;
420 loc = stub_sec->contents + stub_entry->stub_offset;
422 stub_bfd = stub_sec->owner;
424 /* Create the trampoline call stub:
426 pshb
427 ldab #%page(symbol)
428 ldy #%addr(symbol)
429 jmp __trampoline
432 sym_value = (stub_entry->target_value
433 + stub_entry->target_section->output_offset
434 + stub_entry->target_section->output_section->vma);
435 phys_addr = m68hc11_phys_addr (&htab->pinfo, sym_value);
436 phys_page = m68hc11_phys_page (&htab->pinfo, sym_value);
438 /* pshb; ldab #%page(sym) */
439 bfd_put_8 (stub_bfd, 0x37, loc);
440 bfd_put_8 (stub_bfd, 0xC6, loc + 1);
441 bfd_put_8 (stub_bfd, phys_page, loc + 2);
442 loc += 3;
444 /* ldy #%addr(sym) */
445 bfd_put_8 (stub_bfd, 0x18, loc);
446 bfd_put_8 (stub_bfd, 0xCE, loc + 1);
447 bfd_put_16 (stub_bfd, phys_addr, loc + 2);
448 loc += 4;
450 /* jmp __trampoline */
451 bfd_put_8 (stub_bfd, 0x7E, loc);
452 bfd_put_16 (stub_bfd, htab->pinfo.trampoline_addr, loc + 1);
454 return TRUE;
457 /* As above, but don't actually build the stub. Just bump offset so
458 we know stub section sizes. */
460 static bfd_boolean
461 m68hc11_elf_size_one_stub (struct bfd_hash_entry *gen_entry,
462 void *in_arg ATTRIBUTE_UNUSED)
464 struct elf32_m68hc11_stub_hash_entry *stub_entry;
466 /* Massage our args to the form they really have. */
467 stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
469 stub_entry->stub_sec->size += 10;
470 return TRUE;
473 /* Create a 68HC11 ELF linker hash table. */
475 static struct bfd_link_hash_table *
476 m68hc11_elf_bfd_link_hash_table_create (bfd *abfd)
478 struct m68hc11_elf_link_hash_table *ret;
480 ret = m68hc11_elf_hash_table_create (abfd);
481 if (ret == (struct m68hc11_elf_link_hash_table *) NULL)
482 return NULL;
484 ret->size_one_stub = m68hc11_elf_size_one_stub;
485 ret->build_one_stub = m68hc11_elf_build_one_stub;
487 return &ret->root.root;
491 /* 68HC11 Linker Relaxation. */
493 struct m68hc11_direct_relax
495 const char *name;
496 unsigned char code;
497 unsigned char direct_code;
498 } m68hc11_direct_relax_table[] = {
499 { "adca", 0xB9, 0x99 },
500 { "adcb", 0xF9, 0xD9 },
501 { "adda", 0xBB, 0x9B },
502 { "addb", 0xFB, 0xDB },
503 { "addd", 0xF3, 0xD3 },
504 { "anda", 0xB4, 0x94 },
505 { "andb", 0xF4, 0xD4 },
506 { "cmpa", 0xB1, 0x91 },
507 { "cmpb", 0xF1, 0xD1 },
508 { "cpd", 0xB3, 0x93 },
509 { "cpxy", 0xBC, 0x9C },
510 /* { "cpy", 0xBC, 0x9C }, */
511 { "eora", 0xB8, 0x98 },
512 { "eorb", 0xF8, 0xD8 },
513 { "jsr", 0xBD, 0x9D },
514 { "ldaa", 0xB6, 0x96 },
515 { "ldab", 0xF6, 0xD6 },
516 { "ldd", 0xFC, 0xDC },
517 { "lds", 0xBE, 0x9E },
518 { "ldxy", 0xFE, 0xDE },
519 /* { "ldy", 0xFE, 0xDE },*/
520 { "oraa", 0xBA, 0x9A },
521 { "orab", 0xFA, 0xDA },
522 { "sbca", 0xB2, 0x92 },
523 { "sbcb", 0xF2, 0xD2 },
524 { "staa", 0xB7, 0x97 },
525 { "stab", 0xF7, 0xD7 },
526 { "std", 0xFD, 0xDD },
527 { "sts", 0xBF, 0x9F },
528 { "stxy", 0xFF, 0xDF },
529 /* { "sty", 0xFF, 0xDF },*/
530 { "suba", 0xB0, 0x90 },
531 { "subb", 0xF0, 0xD0 },
532 { "subd", 0xB3, 0x93 },
533 { 0, 0, 0 }
536 static struct m68hc11_direct_relax *
537 find_relaxable_insn (unsigned char code)
539 int i;
541 for (i = 0; m68hc11_direct_relax_table[i].name; i++)
542 if (m68hc11_direct_relax_table[i].code == code)
543 return &m68hc11_direct_relax_table[i];
545 return 0;
548 static int
549 compare_reloc (const void *e1, const void *e2)
551 const Elf_Internal_Rela *i1 = (const Elf_Internal_Rela *) e1;
552 const Elf_Internal_Rela *i2 = (const Elf_Internal_Rela *) e2;
554 if (i1->r_offset == i2->r_offset)
555 return 0;
556 else
557 return i1->r_offset < i2->r_offset ? -1 : 1;
560 #define M6811_OP_LDX_IMMEDIATE (0xCE)
562 static void
563 m68hc11_relax_group (bfd *abfd, asection *sec, bfd_byte *contents,
564 unsigned value, unsigned long offset,
565 unsigned long end_group)
567 unsigned char code;
568 unsigned long start_offset;
569 unsigned long ldx_offset = offset;
570 unsigned long ldx_size;
571 int can_delete_ldx;
572 int relax_ldy = 0;
574 /* First instruction of the relax group must be a
575 LDX #value or LDY #value. If this is not the case,
576 ignore the relax group. */
577 code = bfd_get_8 (abfd, contents + offset);
578 if (code == 0x18)
580 relax_ldy++;
581 offset++;
582 code = bfd_get_8 (abfd, contents + offset);
584 ldx_size = offset - ldx_offset + 3;
585 offset += 3;
586 if (code != M6811_OP_LDX_IMMEDIATE || offset >= end_group)
587 return;
590 /* We can remove the LDX/LDY only when all bset/brclr instructions
591 of the relax group have been converted to use direct addressing
592 mode. */
593 can_delete_ldx = 1;
594 while (offset < end_group)
596 unsigned isize;
597 unsigned new_value;
598 int bset_use_y;
600 bset_use_y = 0;
601 start_offset = offset;
602 code = bfd_get_8 (abfd, contents + offset);
603 if (code == 0x18)
605 bset_use_y++;
606 offset++;
607 code = bfd_get_8 (abfd, contents + offset);
610 /* Check the instruction and translate to use direct addressing mode. */
611 switch (code)
613 /* bset */
614 case 0x1C:
615 code = 0x14;
616 isize = 3;
617 break;
619 /* brclr */
620 case 0x1F:
621 code = 0x13;
622 isize = 4;
623 break;
625 /* brset */
626 case 0x1E:
627 code = 0x12;
628 isize = 4;
629 break;
631 /* bclr */
632 case 0x1D:
633 code = 0x15;
634 isize = 3;
635 break;
637 /* This instruction is not recognized and we are not
638 at end of the relax group. Ignore and don't remove
639 the first LDX (we don't know what it is used for...). */
640 default:
641 return;
643 new_value = (unsigned) bfd_get_8 (abfd, contents + offset + 1);
644 new_value += value;
645 if ((new_value & 0xff00) == 0 && bset_use_y == relax_ldy)
647 bfd_put_8 (abfd, code, contents + offset);
648 bfd_put_8 (abfd, new_value, contents + offset + 1);
649 if (start_offset != offset)
651 m68hc11_elf_relax_delete_bytes (abfd, sec, start_offset,
652 offset - start_offset);
653 end_group--;
656 else
658 can_delete_ldx = 0;
660 offset = start_offset + isize;
662 if (can_delete_ldx)
664 /* Remove the move instruction (3 or 4 bytes win). */
665 m68hc11_elf_relax_delete_bytes (abfd, sec, ldx_offset, ldx_size);
669 /* This function handles relaxing for the 68HC11.
672 and somewhat more difficult to support. */
674 static bfd_boolean
675 m68hc11_elf_relax_section (bfd *abfd, asection *sec,
676 struct bfd_link_info *link_info, bfd_boolean *again)
678 Elf_Internal_Shdr *symtab_hdr;
679 Elf_Internal_Shdr *shndx_hdr;
680 Elf_Internal_Rela *internal_relocs;
681 Elf_Internal_Rela *free_relocs = NULL;
682 Elf_Internal_Rela *irel, *irelend;
683 bfd_byte *contents = NULL;
684 bfd_byte *free_contents = NULL;
685 Elf32_External_Sym *free_extsyms = NULL;
686 Elf_Internal_Rela *prev_insn_branch = NULL;
687 Elf_Internal_Rela *prev_insn_group = NULL;
688 unsigned insn_group_value = 0;
689 Elf_Internal_Sym *isymbuf = NULL;
691 /* Assume nothing changes. */
692 *again = FALSE;
694 /* We don't have to do anything for a relocatable link, if
695 this section does not have relocs, or if this is not a
696 code section. */
697 if (link_info->relocatable
698 || (sec->flags & SEC_RELOC) == 0
699 || sec->reloc_count == 0
700 || (sec->flags & SEC_CODE) == 0)
701 return TRUE;
703 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
704 shndx_hdr = &elf_tdata (abfd)->symtab_shndx_hdr;
706 /* Get a copy of the native relocations. */
707 internal_relocs = (_bfd_elf_link_read_relocs
708 (abfd, sec, (PTR) NULL, (Elf_Internal_Rela *) NULL,
709 link_info->keep_memory));
710 if (internal_relocs == NULL)
711 goto error_return;
712 if (! link_info->keep_memory)
713 free_relocs = internal_relocs;
715 /* Checking for branch relaxation relies on the relocations to
716 be sorted on 'r_offset'. This is not guaranteed so we must sort. */
717 qsort (internal_relocs, sec->reloc_count, sizeof (Elf_Internal_Rela),
718 compare_reloc);
720 /* Walk through them looking for relaxing opportunities. */
721 irelend = internal_relocs + sec->reloc_count;
722 for (irel = internal_relocs; irel < irelend; irel++)
724 bfd_vma symval;
725 bfd_vma value;
726 Elf_Internal_Sym *isym;
727 asection *sym_sec;
728 int is_far = 0;
730 /* If this isn't something that can be relaxed, then ignore
731 this reloc. */
732 if (ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_16
733 && ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_RL_JUMP
734 && ELF32_R_TYPE (irel->r_info) != (int) R_M68HC11_RL_GROUP)
736 prev_insn_branch = 0;
737 prev_insn_group = 0;
738 continue;
741 /* Get the section contents if we haven't done so already. */
742 if (contents == NULL)
744 /* Get cached copy if it exists. */
745 if (elf_section_data (sec)->this_hdr.contents != NULL)
746 contents = elf_section_data (sec)->this_hdr.contents;
747 else
749 /* Go get them off disk. */
750 if (!bfd_malloc_and_get_section (abfd, sec, &contents))
751 goto error_return;
755 /* Try to eliminate an unconditional 8 bit pc-relative branch
756 which immediately follows a conditional 8 bit pc-relative
757 branch around the unconditional branch.
759 original: new:
760 bCC lab1 bCC' lab2
761 bra lab2
762 lab1: lab1:
764 This happens when the bCC can't reach lab2 at assembly time,
765 but due to other relaxations it can reach at link time. */
766 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_RL_JUMP)
768 Elf_Internal_Rela *nrel;
769 unsigned char code;
770 unsigned char roffset;
772 prev_insn_branch = 0;
773 prev_insn_group = 0;
775 /* Do nothing if this reloc is the last byte in the section. */
776 if (irel->r_offset + 2 >= sec->size)
777 continue;
779 /* See if the next instruction is an unconditional pc-relative
780 branch, more often than not this test will fail, so we
781 test it first to speed things up. */
782 code = bfd_get_8 (abfd, contents + irel->r_offset + 2);
783 if (code != 0x7e)
784 continue;
786 /* Also make sure the next relocation applies to the next
787 instruction and that it's a pc-relative 8 bit branch. */
788 nrel = irel + 1;
789 if (nrel == irelend
790 || irel->r_offset + 3 != nrel->r_offset
791 || ELF32_R_TYPE (nrel->r_info) != (int) R_M68HC11_16)
792 continue;
794 /* Make sure our destination immediately follows the
795 unconditional branch. */
796 roffset = bfd_get_8 (abfd, contents + irel->r_offset + 1);
797 if (roffset != 3)
798 continue;
800 prev_insn_branch = irel;
801 prev_insn_group = 0;
802 continue;
805 /* Read this BFD's symbols if we haven't done so already. */
806 if (isymbuf == NULL && symtab_hdr->sh_info != 0)
808 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
809 if (isymbuf == NULL)
810 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
811 symtab_hdr->sh_info, 0,
812 NULL, NULL, NULL);
813 if (isymbuf == NULL)
814 goto error_return;
817 /* Get the value of the symbol referred to by the reloc. */
818 if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info)
820 /* A local symbol. */
821 isym = isymbuf + ELF32_R_SYM (irel->r_info);
822 is_far = isym->st_other & STO_M68HC12_FAR;
823 sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
824 symval = (isym->st_value
825 + sym_sec->output_section->vma
826 + sym_sec->output_offset);
828 else
830 unsigned long indx;
831 struct elf_link_hash_entry *h;
833 /* An external symbol. */
834 indx = ELF32_R_SYM (irel->r_info) - symtab_hdr->sh_info;
835 h = elf_sym_hashes (abfd)[indx];
836 BFD_ASSERT (h != NULL);
837 if (h->root.type != bfd_link_hash_defined
838 && h->root.type != bfd_link_hash_defweak)
840 /* This appears to be a reference to an undefined
841 symbol. Just ignore it--it will be caught by the
842 regular reloc processing. */
843 prev_insn_branch = 0;
844 prev_insn_group = 0;
845 continue;
848 is_far = h->other & STO_M68HC12_FAR;
849 isym = 0;
850 sym_sec = h->root.u.def.section;
851 symval = (h->root.u.def.value
852 + sym_sec->output_section->vma
853 + sym_sec->output_offset);
856 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_RL_GROUP)
858 prev_insn_branch = 0;
859 prev_insn_group = 0;
861 /* Do nothing if this reloc is the last byte in the section. */
862 if (irel->r_offset == sec->size)
863 continue;
865 prev_insn_group = irel;
866 insn_group_value = isym->st_value;
867 continue;
870 /* When we relax some bytes, the size of our section changes.
871 This affects the layout of next input sections that go in our
872 output section. When the symbol is part of another section that
873 will go in the same output section as the current one, it's
874 final address may now be incorrect (too far). We must let the
875 linker re-compute all section offsets before processing this
876 reloc. Code example:
878 Initial Final
879 .sect .text section size = 6 section size = 4
880 jmp foo
881 jmp bar
882 .sect .text.foo_bar output_offset = 6 output_offset = 4
883 foo: rts
884 bar: rts
886 If we process the reloc now, the jmp bar is replaced by a
887 relative branch to the initial bar address (output_offset 6). */
888 if (*again && sym_sec != sec
889 && sym_sec->output_section == sec->output_section)
891 prev_insn_group = 0;
892 prev_insn_branch = 0;
893 continue;
896 value = symval;
897 /* Try to turn a far branch to a near branch. */
898 if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_16
899 && prev_insn_branch)
901 bfd_vma offset;
902 unsigned char code;
904 offset = value - (prev_insn_branch->r_offset
905 + sec->output_section->vma
906 + sec->output_offset + 2);
908 /* If the offset is still out of -128..+127 range,
909 leave that far branch unchanged. */
910 if ((offset & 0xff80) != 0 && (offset & 0xff80) != 0xff80)
912 prev_insn_branch = 0;
913 continue;
916 /* Shrink the branch. */
917 code = bfd_get_8 (abfd, contents + prev_insn_branch->r_offset);
918 if (code == 0x7e)
920 code = 0x20;
921 bfd_put_8 (abfd, code, contents + prev_insn_branch->r_offset);
922 bfd_put_8 (abfd, 0xff,
923 contents + prev_insn_branch->r_offset + 1);
924 irel->r_offset = prev_insn_branch->r_offset + 1;
925 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
926 R_M68HC11_PCREL_8);
927 m68hc11_elf_relax_delete_bytes (abfd, sec,
928 irel->r_offset + 1, 1);
930 else
932 code ^= 0x1;
933 bfd_put_8 (abfd, code, contents + prev_insn_branch->r_offset);
934 bfd_put_8 (abfd, 0xff,
935 contents + prev_insn_branch->r_offset + 1);
936 irel->r_offset = prev_insn_branch->r_offset + 1;
937 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
938 R_M68HC11_PCREL_8);
939 m68hc11_elf_relax_delete_bytes (abfd, sec,
940 irel->r_offset + 1, 3);
942 prev_insn_branch = 0;
943 *again = TRUE;
946 /* Try to turn a 16 bit address into a 8 bit page0 address. */
947 else if (ELF32_R_TYPE (irel->r_info) == (int) R_M68HC11_16
948 && (value & 0xff00) == 0)
950 unsigned char code;
951 unsigned short offset;
952 struct m68hc11_direct_relax *rinfo;
954 prev_insn_branch = 0;
955 offset = bfd_get_16 (abfd, contents + irel->r_offset);
956 offset += value;
957 if ((offset & 0xff00) != 0)
959 prev_insn_group = 0;
960 continue;
963 if (prev_insn_group)
965 unsigned long old_sec_size = sec->size;
967 /* Note that we've changed the relocation contents, etc. */
968 elf_section_data (sec)->relocs = internal_relocs;
969 free_relocs = NULL;
971 elf_section_data (sec)->this_hdr.contents = contents;
972 free_contents = NULL;
974 symtab_hdr->contents = (bfd_byte *) isymbuf;
975 free_extsyms = NULL;
977 m68hc11_relax_group (abfd, sec, contents, offset,
978 prev_insn_group->r_offset,
979 insn_group_value);
980 irel = prev_insn_group;
981 prev_insn_group = 0;
982 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
983 R_M68HC11_NONE);
984 if (sec->size != old_sec_size)
985 *again = TRUE;
986 continue;
989 /* Get the opcode. */
990 code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
991 rinfo = find_relaxable_insn (code);
992 if (rinfo == 0)
994 prev_insn_group = 0;
995 continue;
998 /* Note that we've changed the relocation contents, etc. */
999 elf_section_data (sec)->relocs = internal_relocs;
1000 free_relocs = NULL;
1002 elf_section_data (sec)->this_hdr.contents = contents;
1003 free_contents = NULL;
1005 symtab_hdr->contents = (bfd_byte *) isymbuf;
1006 free_extsyms = NULL;
1008 /* Fix the opcode. */
1009 /* printf ("A relaxable case : 0x%02x (%s)\n",
1010 code, rinfo->name); */
1011 bfd_put_8 (abfd, rinfo->direct_code,
1012 contents + irel->r_offset - 1);
1014 /* Delete one byte of data (upper byte of address). */
1015 m68hc11_elf_relax_delete_bytes (abfd, sec, irel->r_offset, 1);
1017 /* Fix the relocation's type. */
1018 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1019 R_M68HC11_8);
1021 /* That will change things, so, we should relax again. */
1022 *again = TRUE;
1024 else if (ELF32_R_TYPE (irel->r_info) == R_M68HC11_16 && !is_far)
1026 unsigned char code;
1027 bfd_vma offset;
1029 prev_insn_branch = 0;
1030 code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
1031 if (code == 0x7e || code == 0xbd)
1033 offset = value - (irel->r_offset
1034 + sec->output_section->vma
1035 + sec->output_offset + 1);
1036 offset += bfd_get_16 (abfd, contents + irel->r_offset);
1038 /* If the offset is still out of -128..+127 range,
1039 leave that far branch unchanged. */
1040 if ((offset & 0xff80) == 0 || (offset & 0xff80) == 0xff80)
1043 /* Note that we've changed the relocation contents, etc. */
1044 elf_section_data (sec)->relocs = internal_relocs;
1045 free_relocs = NULL;
1047 elf_section_data (sec)->this_hdr.contents = contents;
1048 free_contents = NULL;
1050 symtab_hdr->contents = (bfd_byte *) isymbuf;
1051 free_extsyms = NULL;
1053 /* Shrink the branch. */
1054 code = (code == 0x7e) ? 0x20 : 0x8d;
1055 bfd_put_8 (abfd, code,
1056 contents + irel->r_offset - 1);
1057 bfd_put_8 (abfd, 0xff,
1058 contents + irel->r_offset);
1059 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1060 R_M68HC11_PCREL_8);
1061 m68hc11_elf_relax_delete_bytes (abfd, sec,
1062 irel->r_offset + 1, 1);
1063 /* That will change things, so, we should relax again. */
1064 *again = TRUE;
1068 prev_insn_branch = 0;
1069 prev_insn_group = 0;
1072 if (free_relocs != NULL)
1074 free (free_relocs);
1075 free_relocs = NULL;
1078 if (free_contents != NULL)
1080 if (! link_info->keep_memory)
1081 free (free_contents);
1082 else
1084 /* Cache the section contents for elf_link_input_bfd. */
1085 elf_section_data (sec)->this_hdr.contents = contents;
1087 free_contents = NULL;
1090 if (free_extsyms != NULL)
1092 if (! link_info->keep_memory)
1093 free (free_extsyms);
1094 else
1096 /* Cache the symbols for elf_link_input_bfd. */
1097 symtab_hdr->contents = (unsigned char *) isymbuf;
1099 free_extsyms = NULL;
1102 return TRUE;
1104 error_return:
1105 if (free_relocs != NULL)
1106 free (free_relocs);
1107 if (free_contents != NULL)
1108 free (free_contents);
1109 if (free_extsyms != NULL)
1110 free (free_extsyms);
1111 return FALSE;
1114 /* Delete some bytes from a section while relaxing. */
1116 static void
1117 m68hc11_elf_relax_delete_bytes (bfd *abfd, asection *sec,
1118 bfd_vma addr, int count)
1120 Elf_Internal_Shdr *symtab_hdr;
1121 unsigned int sec_shndx;
1122 bfd_byte *contents;
1123 Elf_Internal_Rela *irel, *irelend;
1124 bfd_vma toaddr;
1125 Elf_Internal_Sym *isymbuf, *isym, *isymend;
1126 struct elf_link_hash_entry **sym_hashes;
1127 struct elf_link_hash_entry **end_hashes;
1128 unsigned int symcount;
1130 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1131 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
1133 sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec);
1135 contents = elf_section_data (sec)->this_hdr.contents;
1137 toaddr = sec->size;
1139 irel = elf_section_data (sec)->relocs;
1140 irelend = irel + sec->reloc_count;
1142 /* Actually delete the bytes. */
1143 memmove (contents + addr, contents + addr + count,
1144 (size_t) (toaddr - addr - count));
1146 sec->size -= count;
1148 /* Adjust all the relocs. */
1149 for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++)
1151 unsigned char code;
1152 unsigned char offset;
1153 unsigned short raddr;
1154 unsigned long old_offset;
1155 int branch_pos;
1157 old_offset = irel->r_offset;
1159 /* See if this reloc was for the bytes we have deleted, in which
1160 case we no longer care about it. Don't delete relocs which
1161 represent addresses, though. */
1162 if (ELF32_R_TYPE (irel->r_info) != R_M68HC11_RL_JUMP
1163 && irel->r_offset >= addr && irel->r_offset < addr + count)
1164 irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info),
1165 R_M68HC11_NONE);
1167 if (ELF32_R_TYPE (irel->r_info) == R_M68HC11_NONE)
1168 continue;
1170 /* Get the new reloc address. */
1171 if ((irel->r_offset > addr
1172 && irel->r_offset < toaddr))
1173 irel->r_offset -= count;
1175 /* If this is a PC relative reloc, see if the range it covers
1176 includes the bytes we have deleted. */
1177 switch (ELF32_R_TYPE (irel->r_info))
1179 default:
1180 break;
1182 case R_M68HC11_RL_JUMP:
1183 code = bfd_get_8 (abfd, contents + irel->r_offset);
1184 switch (code)
1186 /* jsr and jmp instruction are also marked with RL_JUMP
1187 relocs but no adjustment must be made. */
1188 case 0x7e:
1189 case 0x9d:
1190 case 0xbd:
1191 continue;
1193 case 0x12:
1194 case 0x13:
1195 branch_pos = 3;
1196 raddr = 4;
1198 /* Special case when we translate a brclr N,y into brclr *<addr>
1199 In this case, the 0x18 page2 prefix is removed.
1200 The reloc offset is not modified but the instruction
1201 size is reduced by 1. */
1202 if (old_offset == addr)
1203 raddr++;
1204 break;
1206 case 0x1e:
1207 case 0x1f:
1208 branch_pos = 3;
1209 raddr = 4;
1210 break;
1212 case 0x18:
1213 branch_pos = 4;
1214 raddr = 5;
1215 break;
1217 default:
1218 branch_pos = 1;
1219 raddr = 2;
1220 break;
1222 offset = bfd_get_8 (abfd, contents + irel->r_offset + branch_pos);
1223 raddr += old_offset;
1224 raddr += ((unsigned short) offset | ((offset & 0x80) ? 0xff00 : 0));
1225 if (irel->r_offset < addr && raddr > addr)
1227 offset -= count;
1228 bfd_put_8 (abfd, offset, contents + irel->r_offset + branch_pos);
1230 else if (irel->r_offset >= addr && raddr <= addr)
1232 offset += count;
1233 bfd_put_8 (abfd, offset, contents + irel->r_offset + branch_pos);
1235 else
1237 /*printf ("Not adjusted 0x%04x [0x%4x 0x%4x]\n", raddr,
1238 irel->r_offset, addr);*/
1241 break;
1245 /* Adjust the local symbols defined in this section. */
1246 isymend = isymbuf + symtab_hdr->sh_info;
1247 for (isym = isymbuf; isym < isymend; isym++)
1249 if (isym->st_shndx == sec_shndx
1250 && isym->st_value > addr
1251 && isym->st_value <= toaddr)
1252 isym->st_value -= count;
1255 /* Now adjust the global symbols defined in this section. */
1256 symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym)
1257 - symtab_hdr->sh_info);
1258 sym_hashes = elf_sym_hashes (abfd);
1259 end_hashes = sym_hashes + symcount;
1260 for (; sym_hashes < end_hashes; sym_hashes++)
1262 struct elf_link_hash_entry *sym_hash = *sym_hashes;
1263 if ((sym_hash->root.type == bfd_link_hash_defined
1264 || sym_hash->root.type == bfd_link_hash_defweak)
1265 && sym_hash->root.u.def.section == sec
1266 && sym_hash->root.u.def.value > addr
1267 && sym_hash->root.u.def.value <= toaddr)
1269 sym_hash->root.u.def.value -= count;
1274 /* Specific sections:
1275 - The .page0 is a data section that is mapped in [0x0000..0x00FF].
1276 Page0 accesses are faster on the M68HC11. Soft registers used by GCC-m6811
1277 are located in .page0.
1278 - The .vectors is the section that represents the interrupt
1279 vectors. */
1280 static const struct bfd_elf_special_section elf32_m68hc11_special_sections[] =
1282 { STRING_COMMA_LEN (".eeprom"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
1283 { STRING_COMMA_LEN (".page0"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
1284 { STRING_COMMA_LEN (".softregs"), 0, SHT_NOBITS, SHF_ALLOC + SHF_WRITE },
1285 { STRING_COMMA_LEN (".vectors"), 0, SHT_PROGBITS, SHF_ALLOC },
1286 { NULL, 0, 0, 0, 0 }
1289 #define ELF_ARCH bfd_arch_m68hc11
1290 #define ELF_MACHINE_CODE EM_68HC11
1291 #define ELF_MAXPAGESIZE 0x1000
1293 #define TARGET_BIG_SYM bfd_elf32_m68hc11_vec
1294 #define TARGET_BIG_NAME "elf32-m68hc11"
1296 #define elf_info_to_howto 0
1297 #define elf_info_to_howto_rel m68hc11_info_to_howto_rel
1298 #define bfd_elf32_bfd_relax_section m68hc11_elf_relax_section
1299 #define elf_backend_check_relocs elf32_m68hc11_check_relocs
1300 #define elf_backend_relocate_section elf32_m68hc11_relocate_section
1301 #define elf_backend_add_symbol_hook elf32_m68hc11_add_symbol_hook
1302 #define elf_backend_object_p 0
1303 #define elf_backend_final_write_processing 0
1304 #define elf_backend_can_gc_sections 1
1305 #define elf_backend_special_sections elf32_m68hc11_special_sections
1307 #define bfd_elf32_bfd_link_hash_table_create \
1308 m68hc11_elf_bfd_link_hash_table_create
1309 #define bfd_elf32_bfd_link_hash_table_free \
1310 m68hc11_elf_bfd_link_hash_table_free
1311 #define bfd_elf32_bfd_merge_private_bfd_data \
1312 _bfd_m68hc11_elf_merge_private_bfd_data
1313 #define bfd_elf32_bfd_set_private_flags _bfd_m68hc11_elf_set_private_flags
1314 #define bfd_elf32_bfd_print_private_bfd_data \
1315 _bfd_m68hc11_elf_print_private_bfd_data
1317 #include "elf32-target.h"