bfd/libaout.h

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