1 /* BFD backend for MIPS BSD (a.out) binaries.
2 Copyright (C) 1993-2016 Free Software Foundation, Inc.
3 Written by Ralph Campbell.
4
5 This file is part of BFD, the Binary File Descriptor library.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20 MA 02110-1301, USA. */
21
22
23 /* #define ENTRY_CAN_BE_ZERO */
24 #define N_HEADER_IN_TEXT(x) 1
25 #define N_TXTADDR(x) \
26 (N_MAGIC(x) != ZMAGIC ? (x)->a_entry : /* object file or NMAGIC */\
27 TEXT_START_ADDR + EXEC_BYTES_SIZE /* no padding */\
28 )
29 #define N_DATADDR(x) (N_TXTADDR(x)+N_TXTSIZE(x))
30 #define TEXT_START_ADDR 4096
31 #define TARGET_PAGE_SIZE 4096
32 #define SEGMENT_SIZE TARGET_PAGE_SIZE
33 #define DEFAULT_ARCH bfd_arch_mips
34 #define MACHTYPE_OK(mtype) ((mtype) == M_UNKNOWN \
35 || (mtype) == M_MIPS1 || (mtype) == M_MIPS2)
36 #define MY_symbol_leading_char '\0'
37
38 /* Do not "beautify" the CONCAT* macro args. Traditional C will not
39 remove whitespace added here, and thus will fail to concatenate
40 the tokens. */
41 #define MY(OP) CONCAT2 (mipsbsd_,OP)
42
43 #include "sysdep.h"
44 #include "bfd.h"
45 #include "libbfd.h"
46 #include "libaout.h"
47
48 #define SET_ARCH_MACH(ABFD, EXECP) \
49 MY(set_arch_mach) (ABFD, N_MACHTYPE (EXECP)); \
50 MY(choose_reloc_size) (ABFD);
51 static void MY(set_arch_mach) (bfd *, unsigned long);
52 static void MY(choose_reloc_size) (bfd *);
53
54 #define MY_write_object_contents MY(write_object_contents)
55 static bfd_boolean MY(write_object_contents) (bfd *);
56
57 /* We can't use MY(x) here because it leads to a recursive call to CONCAT2
58 when expanded inside JUMP_TABLE. */
59 #define MY_bfd_reloc_type_lookup mipsbsd_reloc_type_lookup
60 #define MY_bfd_reloc_name_lookup mipsbsd_reloc_name_lookup
61 #define MY_canonicalize_reloc mipsbsd_canonicalize_reloc
62
63 #define MY_bfd_link_hash_table_create _bfd_generic_link_hash_table_create
64 #define MY_bfd_link_add_symbols _bfd_generic_link_add_symbols
65 #define MY_final_link_callback unused
66 #define MY_bfd_final_link _bfd_generic_final_link
67
68 #define MY_backend_data &MY(backend_data)
69 #define MY_BFD_TARGET
70
71 #include "aout-target.h"
72
73 static bfd_reloc_status_type mips_fix_jmp_addr
74 (bfd *, arelent *, struct bfd_symbol *, void *, asection *,
75 bfd *, char **);
76
77 long MY(canonicalize_reloc) (bfd *, sec_ptr, arelent **, asymbol **);
78
79 static void
MY(set_arch_mach)80 MY(set_arch_mach) (bfd *abfd, unsigned long machtype)
81 {
82 enum bfd_architecture arch;
83 unsigned int machine;
84
85 /* Determine the architecture and machine type of the object file. */
86 switch (machtype)
87 {
88 case M_MIPS1:
89 arch = bfd_arch_mips;
90 machine = bfd_mach_mips3000;
91 break;
92
93 case M_MIPS2:
94 arch = bfd_arch_mips;
95 machine = bfd_mach_mips4000;
96 break;
97
98 default:
99 arch = bfd_arch_obscure;
100 machine = 0;
101 break;
102 }
103
104 bfd_set_arch_mach (abfd, arch, machine);
105 }
106
107 /* Determine the size of a relocation entry, based on the architecture */
108 static void
MY(choose_reloc_size)109 MY (choose_reloc_size) (bfd *abfd)
110 {
111 switch (bfd_get_arch (abfd))
112 {
113 case bfd_arch_sparc:
114 case bfd_arch_mips:
115 obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;
116 break;
117 default:
118 obj_reloc_entry_size (abfd) = RELOC_STD_SIZE;
119 break;
120 }
121 }
122
123 /* Write an object file in BSD a.out format.
124 Section contents have already been written. We write the
125 file header, symbols, and relocation. */
126
127 static bfd_boolean
MY(write_object_contents)128 MY (write_object_contents) (bfd *abfd)
129 {
130 struct external_exec exec_bytes;
131 struct internal_exec *execp = exec_hdr (abfd);
132
133 /* Magic number, maestro, please! */
134 switch (bfd_get_arch (abfd))
135 {
136 case bfd_arch_m68k:
137 switch (bfd_get_mach (abfd))
138 {
139 case bfd_mach_m68010:
140 N_SET_MACHTYPE (execp, M_68010);
141 break;
142 default:
143 case bfd_mach_m68020:
144 N_SET_MACHTYPE (execp, M_68020);
145 break;
146 }
147 break;
148 case bfd_arch_sparc:
149 N_SET_MACHTYPE (execp, M_SPARC);
150 break;
151 case bfd_arch_i386:
152 N_SET_MACHTYPE (execp, M_386);
153 break;
154 case bfd_arch_mips:
155 switch (bfd_get_mach (abfd))
156 {
157 case bfd_mach_mips4000:
158 case bfd_mach_mips6000:
159 N_SET_MACHTYPE (execp, M_MIPS2);
160 break;
161 default:
162 N_SET_MACHTYPE (execp, M_MIPS1);
163 break;
164 }
165 break;
166 default:
167 N_SET_MACHTYPE (execp, M_UNKNOWN);
168 }
169
170 MY (choose_reloc_size) (abfd);
171
172 WRITE_HEADERS (abfd, execp);
173
174 return TRUE;
175 }
176
177 /* MIPS relocation types. */
178 #define MIPS_RELOC_32 0
179 #define MIPS_RELOC_JMP 1
180 #define MIPS_RELOC_WDISP16 2
181 #define MIPS_RELOC_HI16 3
182 #define MIPS_RELOC_HI16_S 4
183 #define MIPS_RELOC_LO16 5
184
185 /* This is only called when performing a BFD_RELOC_MIPS_JMP relocation.
186 The jump destination address is formed from the upper 4 bits of the
187 "current" program counter concatenated with the jump instruction's
188 26 bit field and two trailing zeros.
189 If the destination address is not in the same segment as the "current"
190 program counter, then we need to signal an error. */
191
192 static bfd_reloc_status_type
mips_fix_jmp_addr(bfd * abfd ATTRIBUTE_UNUSED,arelent * reloc_entry,struct bfd_symbol * symbol,void * data ATTRIBUTE_UNUSED,asection * input_section,bfd * output_bfd,char ** error_message ATTRIBUTE_UNUSED)193 mips_fix_jmp_addr (bfd *abfd ATTRIBUTE_UNUSED,
194 arelent *reloc_entry,
195 struct bfd_symbol *symbol,
196 void * data ATTRIBUTE_UNUSED,
197 asection *input_section,
198 bfd *output_bfd,
199 char **error_message ATTRIBUTE_UNUSED)
200 {
201 bfd_vma relocation, pc;
202
203 /* If this is a partial relocation, just continue. */
204 if (output_bfd != (bfd *) NULL)
205 return bfd_reloc_continue;
206
207 /* If this is an undefined symbol, return error */
208 if (bfd_is_und_section (symbol->section)
209 && (symbol->flags & BSF_WEAK) == 0)
210 return bfd_reloc_undefined;
211
212 /* Work out which section the relocation is targeted at and the
213 initial relocation command value. */
214 if (bfd_is_com_section (symbol->section))
215 relocation = 0;
216 else
217 relocation = symbol->value;
218
219 relocation += symbol->section->output_section->vma;
220 relocation += symbol->section->output_offset;
221 relocation += reloc_entry->addend;
222
223 pc = input_section->output_section->vma + input_section->output_offset +
224 reloc_entry->address + 4;
225
226 if ((relocation & 0xF0000000) != (pc & 0xF0000000))
227 return bfd_reloc_overflow;
228
229 return bfd_reloc_continue;
230 }
231
232 /* This is only called when performing a BFD_RELOC_HI16_S relocation.
233 We need to see if bit 15 is set in the result. If it is, we add
234 0x10000 and continue normally. This will compensate for the sign extension
235 when the low bits are added at run time. */
236
237 static bfd_reloc_status_type
mips_fix_hi16_s(bfd * abfd ATTRIBUTE_UNUSED,arelent * reloc_entry,asymbol * symbol,void * data ATTRIBUTE_UNUSED,asection * input_section ATTRIBUTE_UNUSED,bfd * output_bfd,char ** error_message ATTRIBUTE_UNUSED)238 mips_fix_hi16_s (bfd *abfd ATTRIBUTE_UNUSED,
239 arelent *reloc_entry,
240 asymbol *symbol,
241 void * data ATTRIBUTE_UNUSED,
242 asection *input_section ATTRIBUTE_UNUSED,
243 bfd *output_bfd,
244 char **error_message ATTRIBUTE_UNUSED)
245 {
246 bfd_vma relocation;
247
248 /* If this is a partial relocation, just continue. */
249 if (output_bfd != (bfd *)NULL)
250 return bfd_reloc_continue;
251
252 /* If this is an undefined symbol, return error. */
253 if (bfd_is_und_section (symbol->section)
254 && (symbol->flags & BSF_WEAK) == 0)
255 return bfd_reloc_undefined;
256
257 /* Work out which section the relocation is targeted at and the
258 initial relocation command value. */
259 if (bfd_is_com_section (symbol->section))
260 relocation = 0;
261 else
262 relocation = symbol->value;
263
264 relocation += symbol->section->output_section->vma;
265 relocation += symbol->section->output_offset;
266 relocation += reloc_entry->addend;
267
268 if (relocation & 0x8000)
269 reloc_entry->addend += 0x10000;
270
271 return bfd_reloc_continue;
272 }
273
274 static reloc_howto_type mips_howto_table_ext[] =
275 {
276 {MIPS_RELOC_32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, 0,
277 "32", FALSE, 0, 0xffffffff, FALSE},
278 {MIPS_RELOC_JMP, 2, 2, 26, FALSE, 0, complain_overflow_dont,
279 mips_fix_jmp_addr,
280 "MIPS_JMP", FALSE, 0, 0x03ffffff, FALSE},
281 {MIPS_RELOC_WDISP16, 2, 2, 16, TRUE, 0, complain_overflow_signed, 0,
282 "WDISP16", FALSE, 0, 0x0000ffff, FALSE},
283 {MIPS_RELOC_HI16, 16, 2, 16, FALSE, 0, complain_overflow_bitfield, 0,
284 "HI16", FALSE, 0, 0x0000ffff, FALSE},
285 {MIPS_RELOC_HI16_S, 16, 2, 16, FALSE, 0, complain_overflow_bitfield,
286 mips_fix_hi16_s,
287 "HI16_S", FALSE, 0, 0x0000ffff, FALSE},
288 {MIPS_RELOC_LO16, 0, 2, 16, FALSE, 0, complain_overflow_dont, 0,
289 "LO16", FALSE, 0, 0x0000ffff, FALSE},
290 };
291
292 static reloc_howto_type *
MY(reloc_type_lookup)293 MY(reloc_type_lookup) (bfd *abfd, bfd_reloc_code_real_type code)
294 {
295 if (bfd_get_arch (abfd) != bfd_arch_mips)
296 return NULL;
297
298 switch (code)
299 {
300 case BFD_RELOC_CTOR:
301 case BFD_RELOC_32:
302 return (&mips_howto_table_ext[MIPS_RELOC_32]);
303 case BFD_RELOC_MIPS_JMP:
304 return (&mips_howto_table_ext[MIPS_RELOC_JMP]);
305 case BFD_RELOC_16_PCREL_S2:
306 return (&mips_howto_table_ext[MIPS_RELOC_WDISP16]);
307 case BFD_RELOC_HI16:
308 return (&mips_howto_table_ext[MIPS_RELOC_HI16]);
309 case BFD_RELOC_HI16_S:
310 return (&mips_howto_table_ext[MIPS_RELOC_HI16_S]);
311 case BFD_RELOC_LO16:
312 return (&mips_howto_table_ext[MIPS_RELOC_LO16]);
313 default:
314 return NULL;
315 }
316 }
317
318 static reloc_howto_type *
MY(reloc_name_lookup)319 MY(reloc_name_lookup) (bfd *abfd ATTRIBUTE_UNUSED,
320 const char *r_name)
321 {
322 unsigned int i;
323
324 for (i = 0;
325 i < sizeof (mips_howto_table_ext) / sizeof (mips_howto_table_ext[0]);
326 i++)
327 if (mips_howto_table_ext[i].name != NULL
328 && strcasecmp (mips_howto_table_ext[i].name, r_name) == 0)
329 return &mips_howto_table_ext[i];
330
331 return NULL;
332 }
333
334 /* This is just like the standard aoutx.h version but we need to do our
335 own mapping of external reloc type values to howto entries. */
336 long
MY(canonicalize_reloc)337 MY(canonicalize_reloc) (bfd *abfd,
338 sec_ptr section,
339 arelent **relptr,
340 asymbol **symbols)
341 {
342 arelent *tblptr = section->relocation;
343 unsigned int count, c;
344 extern reloc_howto_type NAME(aout,ext_howto_table)[];
345
346 /* If we have already read in the relocation table, return the values. */
347 if (section->flags & SEC_CONSTRUCTOR)
348 {
349 arelent_chain *chain = section->constructor_chain;
350
351 for (count = 0; count < section->reloc_count; count++)
352 {
353 *relptr++ = &chain->relent;
354 chain = chain->next;
355 }
356 *relptr = 0;
357 return section->reloc_count;
358 }
359
360 if (tblptr && section->reloc_count)
361 {
362 for (count = 0; count++ < section->reloc_count;)
363 *relptr++ = tblptr++;
364 *relptr = 0;
365 return section->reloc_count;
366 }
367
368 if (!NAME(aout,slurp_reloc_table) (abfd, section, symbols))
369 return -1;
370 tblptr = section->relocation;
371
372 /* fix up howto entries. */
373 for (count = 0; count++ < section->reloc_count;)
374 {
375 c = tblptr->howto - NAME(aout,ext_howto_table);
376 tblptr->howto = &mips_howto_table_ext[c];
377
378 *relptr++ = tblptr++;
379 }
380 *relptr = 0;
381 return section->reloc_count;
382 }
383
384 static const struct aout_backend_data MY(backend_data) =
385 {
386 0, /* zmagic contiguous */
387 1, /* text incl header */
388 0, /* entry is text address */
389 0, /* exec_hdr_flags */
390 TARGET_PAGE_SIZE, /* text vma */
391 MY_set_sizes,
392 0, /* text size includes exec header */
393 0, /* add_dynamic_symbols */
394 0, /* add_one_symbol */
395 0, /* link_dynamic_object */
396 0, /* write_dynamic_symbol */
397 0, /* check_dynamic_reloc */
398 0 /* finish_dynamic_link */
399 };
400
401 extern const bfd_target mips_aout_be_vec;
402
403 const bfd_target mips_aout_le_vec =
404 {
405 "a.out-mips-little", /* name */
406 bfd_target_aout_flavour,
407 BFD_ENDIAN_LITTLE, /* target byte order (little) */
408 BFD_ENDIAN_LITTLE, /* target headers byte order (little) */
409 (HAS_RELOC | EXEC_P | /* object flags */
410 HAS_LINENO | HAS_DEBUG |
411 HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
412 (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_CODE | SEC_DATA),
413 MY_symbol_leading_char,
414 ' ', /* ar_pad_char */
415 15, /* ar_max_namelen */
416 0, /* match priority. */
417 bfd_getl64, bfd_getl_signed_64, bfd_putl64,
418 bfd_getl32, bfd_getl_signed_32, bfd_putl32,
419 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
420 bfd_getl64, bfd_getl_signed_64, bfd_putl64,
421 bfd_getl32, bfd_getl_signed_32, bfd_putl32,
422 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
423 {_bfd_dummy_target, MY_object_p, /* bfd_check_format */
424 bfd_generic_archive_p, MY_core_file_p},
425 {bfd_false, MY_mkobject, /* bfd_set_format */
426 _bfd_generic_mkarchive, bfd_false},
427 {bfd_false, MY_write_object_contents, /* bfd_write_contents */
428 _bfd_write_archive_contents, bfd_false},
429
430 BFD_JUMP_TABLE_GENERIC (MY),
431 BFD_JUMP_TABLE_COPY (MY),
432 BFD_JUMP_TABLE_CORE (MY),
433 BFD_JUMP_TABLE_ARCHIVE (MY),
434 BFD_JUMP_TABLE_SYMBOLS (MY),
435 BFD_JUMP_TABLE_RELOCS (MY),
436 BFD_JUMP_TABLE_WRITE (MY),
437 BFD_JUMP_TABLE_LINK (MY),
438 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
439
440 & mips_aout_be_vec,
441
442 MY_backend_data
443 };
444
445 const bfd_target mips_aout_be_vec =
446 {
447 "a.out-mips-big", /* name */
448 bfd_target_aout_flavour,
449 BFD_ENDIAN_BIG, /* target byte order (big) */
450 BFD_ENDIAN_BIG, /* target headers byte order (big) */
451 (HAS_RELOC | EXEC_P | /* object flags */
452 HAS_LINENO | HAS_DEBUG |
453 HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
454 (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_CODE | SEC_DATA),
455 MY_symbol_leading_char,
456 ' ', /* ar_pad_char */
457 15, /* ar_max_namelen */
458 0, /* match priority. */
459 bfd_getb64, bfd_getb_signed_64, bfd_putb64,
460 bfd_getb32, bfd_getb_signed_32, bfd_putb32,
461 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */
462 bfd_getb64, bfd_getb_signed_64, bfd_putb64,
463 bfd_getb32, bfd_getb_signed_32, bfd_putb32,
464 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */
465 {_bfd_dummy_target, MY_object_p, /* bfd_check_format */
466 bfd_generic_archive_p, MY_core_file_p},
467 {bfd_false, MY_mkobject, /* bfd_set_format */
468 _bfd_generic_mkarchive, bfd_false},
469 {bfd_false, MY_write_object_contents, /* bfd_write_contents */
470 _bfd_write_archive_contents, bfd_false},
471
472 BFD_JUMP_TABLE_GENERIC (MY),
473 BFD_JUMP_TABLE_COPY (MY),
474 BFD_JUMP_TABLE_CORE (MY),
475 BFD_JUMP_TABLE_ARCHIVE (MY),
476 BFD_JUMP_TABLE_SYMBOLS (MY),
477 BFD_JUMP_TABLE_RELOCS (MY),
478 BFD_JUMP_TABLE_WRITE (MY),
479 BFD_JUMP_TABLE_LINK (MY),
480 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
481
482 & mips_aout_le_vec,
483
484 MY_backend_data
485 };
486