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