bfd/libaout.h

   1 /* BFD back-end data structures for a.out (and similar) files.
   2    Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
   3    Written by Cygnus Support.
   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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 /* We try to encapsulate the differences in the various a.out file
  22    variants in a few routines, and otherwise share large masses of code.
  23    This means we only have to fix bugs in one place, most of the time.  */
  24
  25 /* Parameterize the a.out code based on whether it is being built
  26    for a 32-bit architecture or a 64-bit architecture.  */
  27 #if ARCH_SIZE==64
  28 #define GET_WORD bfd_h_get_64
  29 #define GET_SWORD (int64_type)GET_WORD
  30 #define PUT_WORD bfd_h_put_64
  31 #ifndef NAME
  32 #define NAME(x,y) CAT3(x,_64_,y)
  33 #endif
  34 #define JNAME(x) CAT(x,_64)
  35 #define BYTES_IN_WORD 8
  36 #else /* ARCH_SIZE == 32 */
  37 #define GET_WORD bfd_h_get_32
  38 #define GET_SWORD (int32_type)GET_WORD
  39 #define PUT_WORD bfd_h_put_32
  40 #ifndef NAME
  41 #define NAME(x,y) CAT3(x,_32_,y)
  42 #endif
  43 #define JNAME(x) CAT(x,_32)
  44 #define BYTES_IN_WORD 4
  45 #endif /* ARCH_SIZE==32 */
  46
  47 /* Declare these types at file level, since they are used in parameter
  48    lists, which have wierd scope.  */
  49 struct external_exec;
  50 struct internal_exec;
  51
  52 /* Back-end information for various a.out targets.  */
  53 struct aout_backend_data
  54 {
  55   /* Are ZMAGIC files mapped contiguously?  If so, the text section may
  56      need more padding, if the segment size (granularity for memory access
  57      control) is larger than the page size.  */
  58   unsigned char zmagic_mapped_contiguous;
  59   /* If this flag is set, ZMAGIC/NMAGIC file headers get mapped in with the
  60      text section, which starts immediately after the file header.
  61      If not, the text section starts on the next page.  */
  62   unsigned char text_includes_header;
  63
  64   /* If the text section VMA isn't specified, and we need an absolute
  65      address, use this as the default.  If we're producing a relocatable
  66      file, zero is always used.  */
  67   /* ?? Perhaps a callback would be a better choice?  Will this do anything
  68      reasonable for a format that handles multiple CPUs with different
  69      load addresses for each?  */
  70   bfd_vma default_text_vma;
  71
  72   /* Callback for setting the page and segment sizes, if they can't be
  73      trivially determined from the architecture.  */
  74   boolean (*set_sizes) PARAMS ((bfd *));
  75
  76   /* zmagic files only. For go32, the length of the exec header contributes
  77      to the size of the text section in the file for alignment purposes but
  78      does *not* get counted in the length of the text section. */
  79   unsigned char exec_header_not_counted;
  80 };
  81 #define aout_backend_info(abfd) \
  82         ((CONST struct aout_backend_data *)((abfd)->xvec->backend_data))
  83
  84 /* This is the layout in memory of a "struct exec" while we process it.
  85    All 'lengths' are given as a number of bytes.
  86    All 'alignments' are for relinkable files only;  an alignment of
  87         'n' indicates the corresponding segment must begin at an
  88         address that is a multiple of (2**n).  */
  89
  90 struct internal_exec
  91 {
  92     long a_info;                /* Magic number and flags, packed */
  93     bfd_vma a_text;             /* length of text, in bytes  */
  94     bfd_vma a_data;             /* length of data, in bytes  */
  95     bfd_vma a_bss;              /* length of uninitialized data area in mem */
  96     bfd_vma a_syms;             /* length of symbol table data in file */
  97     bfd_vma a_entry;            /* start address */
  98     bfd_vma a_trsize;           /* length of text's relocation info, in bytes */
  99     bfd_vma a_drsize;           /* length of data's relocation info, in bytes */
 100     /* Added for i960 */
 101     bfd_vma a_tload;            /* Text runtime load address */
 102     bfd_vma a_dload;            /* Data runtime load address */
 103     unsigned char a_talign;     /* Alignment of text segment */
 104     unsigned char a_dalign;     /* Alignment of data segment */
 105     unsigned char a_balign;     /* Alignment of bss segment */
 106     char a_relaxable;           /* Enough info for linker relax */
 107 };
 108
 109 /* Magic number is written
 110 < MSB        >
 111 3130292827262524232221201918171615141312111009080706050403020100
 112 < FLAGS      >< MACHINE TYPE ><  MAGIC NUMBER                  >
 113 */
 114 enum machine_type {
 115   M_UNKNOWN = 0,
 116   M_68010 = 1,
 117   M_68020 = 2,
 118   M_SPARC = 3,
 119   /* skip a bunch so we don't run into any of suns numbers */
 120   M_386 = 100,
 121   M_29K = 101,          /* AMD 29000 */
 122   M_MIPS1 = 151,        /* MIPS R2000/R3000 binary */
 123   M_MIPS2 = 152,        /* MIPS R4000/R6000 binary */
 124   M_HP200 = 200,        /* HP 200 (68010) BSD binary */
 125   M_HP300 = (300 % 256), /* HP 300 (68020+68881) BSD binary */
 126   M_HPUX = (0x20c % 256)/* HP 200/300 HPUX binary */
 127 };
 128
 129 #define N_DYNAMIC(exec) ((exec).a_info & 0x8000000)
 130
 131 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
 132 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 133 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 134 #define N_SET_INFO(exec, magic, type, flags) \
 135 ((exec).a_info = ((magic) & 0xffff) \
 136  | (((int)(type) & 0xff) << 16) \
 137  | (((flags) & 0xff) << 24))
 138
 139 #define N_SET_MAGIC(exec, magic) \
 140 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 141
 142 #define N_SET_MACHTYPE(exec, machtype) \
 143 ((exec).a_info = \
 144  ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 145
 146 #define N_SET_FLAGS(exec, flags) \
 147 ((exec).a_info = \
 148  ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 149
 150 typedef struct aout_symbol {
 151   asymbol symbol;
 152   short desc;
 153   char other;
 154   unsigned char type;
 155 } aout_symbol_type;
 156
 157 /* The `tdata' struct for all a.out-like object file formats.
 158    Various things depend on this struct being around any time an a.out
 159    file is being handled.  An example is dbxread.c in GDB.  */
 160
 161 struct aoutdata {
 162   struct internal_exec *hdr;            /* exec file header */
 163   aout_symbol_type *symbols;            /* symtab for input bfd */
 164
 165   /* For ease, we do this */
 166   asection *textsec;
 167   asection *datasec;
 168   asection *bsssec;
 169
 170   /* We remember these offsets so that after check_file_format, we have
 171      no dependencies on the particular format of the exec_hdr.  */
 172   file_ptr sym_filepos;
 173   file_ptr str_filepos;
 174
 175   /* Size of a relocation entry in external form */
 176   unsigned reloc_entry_size;
 177
 178   /* Size of a symbol table entry in external form */
 179   unsigned symbol_entry_size;
 180
 181   /* Page size - needed for alignment of demand paged files. */
 182   unsigned long page_size;
 183
 184   /* Segment size - needed for alignment of demand paged files. */
 185   unsigned long segment_size;
 186
 187   unsigned exec_bytes_size;
 188   unsigned vma_adjusted : 1;
 189
 190   /* used when a bfd supports several highly similar formats */
 191   enum {
 192     default_format = 0,
 193     gnu_encap_format } subformat;
 194
 195   enum {
 196     undecided_magic = 0,
 197     z_magic,
 198     o_magic,
 199     n_magic } magic;
 200 };
 201
 202 struct  aout_data_struct {
 203     struct aoutdata a;
 204     struct internal_exec e;
 205 };
 206
 207 #define adata(bfd)              ((bfd)->tdata.aout_data->a)
 208 #define exec_hdr(bfd)           (adata(bfd).hdr)
 209 #define obj_aout_symbols(bfd)   (adata(bfd).symbols)
 210 #define obj_textsec(bfd)        (adata(bfd).textsec)
 211 #define obj_datasec(bfd)        (adata(bfd).datasec)
 212 #define obj_bsssec(bfd)         (adata(bfd).bsssec)
 213 #define obj_sym_filepos(bfd)    (adata(bfd).sym_filepos)
 214 #define obj_str_filepos(bfd)    (adata(bfd).str_filepos)
 215 #define obj_reloc_entry_size(bfd) (adata(bfd).reloc_entry_size)
 216 #define obj_symbol_entry_size(bfd) (adata(bfd).symbol_entry_size)
 217 #define obj_aout_subformat(bfd) (adata(bfd).subformat)
 218
 219 /* We take the address of the first element of an asymbol to ensure that the
 220    macro is only ever applied to an asymbol */
 221 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
 222
 223 /* Prototype declarations for functions defined in aoutx.h  */
 224
 225 boolean
 226 NAME(aout,squirt_out_relocs) PARAMS ((bfd *abfd, asection *section));
 227
 228 bfd_target *
 229 NAME(aout,some_aout_object_p) PARAMS ((bfd *abfd,
 230                         struct internal_exec *execp,
 231                         bfd_target * (*callback)(bfd *)));
 232
 233 boolean
 234 NAME(aout,mkobject) PARAMS ((bfd *abfd));
 235
 236 enum machine_type
 237 NAME(aout,machine_type) PARAMS ((enum bfd_architecture arch,
 238                                  unsigned long machine));
 239
 240 boolean
 241 NAME(aout,set_arch_mach) PARAMS ((bfd *abfd, enum bfd_architecture arch,
 242                                   unsigned long machine));
 243
 244 boolean
 245 NAME(aout,new_section_hook) PARAMS ((bfd *abfd, asection *newsect));
 246
 247 boolean
 248 NAME(aout,set_section_contents) PARAMS ((bfd *abfd, sec_ptr section,
 249                          PTR location, file_ptr offset, bfd_size_type count));
 250
 251 asymbol *
 252 NAME(aout,make_empty_symbol) PARAMS ((bfd *abfd));
 253
 254 boolean
 255 NAME(aout,slurp_symbol_table) PARAMS ((bfd *abfd));
 256
 257 void
 258 NAME(aout,write_syms) PARAMS ((bfd *abfd));
 259
 260 void
 261 NAME(aout,reclaim_symbol_table) PARAMS ((bfd *abfd));
 262
 263 unsigned int
 264 NAME(aout,get_symtab_upper_bound) PARAMS ((bfd *abfd));
 265
 266 unsigned int
 267 NAME(aout,get_symtab) PARAMS ((bfd *abfd, asymbol **location));
 268
 269 boolean
 270 NAME(aout,slurp_reloc_table) PARAMS ((bfd *abfd, sec_ptr asect,
 271                                       asymbol **symbols));
 272
 273 unsigned int
 274 NAME(aout,canonicalize_reloc) PARAMS ((bfd *abfd, sec_ptr section,
 275                                        arelent **relptr, asymbol **symbols));
 276
 277 unsigned int
 278 NAME(aout,get_reloc_upper_bound) PARAMS ((bfd *abfd, sec_ptr asect));
 279
 280 void
 281 NAME(aout,reclaim_reloc) PARAMS ((bfd *ignore_abfd, sec_ptr ignore));
 282
 283 alent *
 284 NAME(aout,get_lineno) PARAMS ((bfd *ignore_abfd, asymbol *ignore_symbol));
 285
 286 void
 287 NAME(aout,print_symbol) PARAMS ((bfd *ignore_abfd, PTR file,
 288                             asymbol *symbol, bfd_print_symbol_type how));
 289
 290 void
 291 NAME(aout,get_symbol_info) PARAMS ((bfd *ignore_abfd,
 292                            asymbol *symbol, symbol_info *ret));
 293
 294 boolean
 295 NAME(aout,close_and_cleanup) PARAMS ((bfd *abfd));
 296
 297 boolean
 298 NAME(aout,find_nearest_line) PARAMS ((bfd *abfd, asection *section,
 299       asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
 300       CONST char **functionname_ptr, unsigned int *line_ptr));
 301
 302 int
 303 NAME(aout,sizeof_headers) PARAMS ((bfd *abfd, boolean exec));
 304
 305 boolean
 306 NAME(aout,adjust_sizes_and_vmas) PARAMS ((bfd *abfd,
 307        bfd_size_type *text_size, file_ptr *text_end));
 308
 309 void
 310 NAME(aout,swap_exec_header_in) PARAMS ((bfd *abfd,
 311        struct external_exec *raw_bytes, struct internal_exec *execp));
 312
 313 void
 314 NAME(aout,swap_exec_header_out) PARAMS ((bfd *abfd,
 315        struct internal_exec *execp, struct external_exec *raw_bytes));
 316
 317 /* Prototypes for functions in stab-syms.c. */
 318
 319 CONST char *
 320 aout_stab_name PARAMS ((int code));
 321
 322 /* A.out uses the generic versions of these routines... */
 323
 324 #define aout_32_get_section_contents    bfd_generic_get_section_contents
 325 #define aout_32_close_and_cleanup       bfd_generic_close_and_cleanup
 326
 327 #define aout_64_get_section_contents    bfd_generic_get_section_contents
 328 #define aout_64_close_and_cleanup       bfd_generic_close_and_cleanup
 329 #ifndef NO_WRITE_HEADER_KLUDGE
 330 #define NO_WRITE_HEADER_KLUDGE 0
 331 #endif
 332
 333 #ifndef WRITE_HEADERS
 334 #define WRITE_HEADERS(abfd, execp)                                            \
 335       {                                                                       \
 336         bfd_size_type text_size; /* dummy vars */                             \
 337         file_ptr text_end;                                                    \
 338         if (adata(abfd).magic == undecided_magic)                             \
 339           NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end);     \
 340                                                                               \
 341         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
 342         execp->a_entry = bfd_get_start_address (abfd);                        \
 343                                                                               \
 344         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
 345                            obj_reloc_entry_size (abfd));                      \
 346         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
 347                            obj_reloc_entry_size (abfd));                      \
 348         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
 349                                                                               \
 350         bfd_seek (abfd, (file_ptr) 0, SEEK_SET);                              \
 351         bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd);              \
 352         /* Now write out reloc info, followed by syms and strings */          \
 353                                                                               \
 354         if (bfd_get_symcount (abfd) != 0)                                     \
 355             {                                                                 \
 356               bfd_seek (abfd, (file_ptr)(N_SYMOFF(*execp)), SEEK_SET);        \
 357                                                                               \
 358               NAME(aout,write_syms)(abfd);                                    \
 359                                                                               \
 360               bfd_seek (abfd, (file_ptr)(N_TRELOFF(*execp)), SEEK_SET);       \
 361                                                                               \
 362               if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd))) return false; \
 363               bfd_seek (abfd, (file_ptr)(N_DRELOFF(*execp)), SEEK_SET);       \
 364                                                                               \
 365               if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd))) return false; \
 366             }                                                                 \
 367       }
 368 #endif