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 #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 dont run into any of suns numbers */
 122   M_386 = 100,
 123   M_29K = 101,
 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   enum {
 191     undecided_magic = 0,
 192     z_magic,
 193     o_magic,
 194     n_magic } magic;
 195 };
 196
 197 struct  aout_data_struct {
 198     struct aoutdata a;
 199     struct internal_exec e;
 200 };
 201
 202 #define adata(bfd)              ((bfd)->tdata.aout_data->a)
 203 #define exec_hdr(bfd)           (adata(bfd).hdr)
 204 #define obj_aout_symbols(bfd)   (adata(bfd).symbols)
 205 #define obj_textsec(bfd)        (adata(bfd).textsec)
 206 #define obj_datasec(bfd)        (adata(bfd).datasec)
 207 #define obj_bsssec(bfd)         (adata(bfd).bsssec)
 208 #define obj_sym_filepos(bfd)    (adata(bfd).sym_filepos)
 209 #define obj_str_filepos(bfd)    (adata(bfd).str_filepos)
 210 #define obj_reloc_entry_size(bfd) (adata(bfd).reloc_entry_size)
 211 #define obj_symbol_entry_size(bfd) (adata(bfd).symbol_entry_size)
 212
 213 /* We take the address of the first element of an asymbol to ensure that the
 214    macro is only ever applied to an asymbol */
 215 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
 216
 217 /* Prototype declarations for functions defined in aoutx.h  */
 218
 219 PROTO (boolean, NAME(aout,squirt_out_relocs),(bfd *abfd, asection *section));
 220
 221 PROTO (bfd_target *, NAME(aout,some_aout_object_p), (bfd *abfd,
 222                                           struct internal_exec *execp,
 223                                           bfd_target *(*callback)()));
 224 PROTO (boolean, NAME(aout,mkobject), (bfd *abfd));
 225 PROTO (enum machine_type, NAME(aout,machine_type), (enum bfd_architecture arch,
 226                                                 unsigned long machine));
 227 PROTO (boolean, NAME(aout,set_arch_mach), (bfd *abfd, enum bfd_architecture arch,
 228                                                 unsigned long machine));
 229
 230 PROTO (boolean, NAME(aout,new_section_hook), (bfd *abfd, asection *newsect));
 231 PROTO (boolean, NAME(aout,set_section_contents), (bfd *abfd, sec_ptr section,
 232                          PTR location, file_ptr offset, bfd_size_type count));
 233
 234 PROTO (asymbol *,NAME(aout,make_empty_symbol), (bfd *abfd));
 235 PROTO (boolean, NAME(aout,slurp_symbol_table), (bfd *abfd));
 236 PROTO (void,    NAME(aout,write_syms), (bfd *abfd));
 237 PROTO (void,    NAME(aout,reclaim_symbol_table), (bfd *abfd));
 238 PROTO (unsigned int, NAME(aout,get_symtab_upper_bound), (bfd *abfd));
 239 PROTO (unsigned int, NAME(aout,get_symtab), (bfd *abfd, asymbol **location));
 240 PROTO (boolean, NAME(aout,slurp_reloc_table), (bfd *abfd, sec_ptr asect,
 241                                          asymbol **symbols));
 242 PROTO (unsigned int, NAME(aout,canonicalize_reloc), (bfd *abfd, sec_ptr section,
 243                                          arelent **relptr, asymbol **symbols));
 244 PROTO (unsigned int, NAME(aout,get_reloc_upper_bound), (bfd *abfd, sec_ptr asect));
 245 PROTO (void,    NAME(aout,reclaim_reloc), (bfd *ignore_abfd, sec_ptr ignore));
 246 PROTO (alent *, NAME(aout,get_lineno), (bfd *ignore_abfd, asymbol *ignore_symbol));
 247 PROTO (void,    NAME(aout,print_symbol), (bfd *ignore_abfd, PTR file,
 248                             asymbol *symbol, bfd_print_symbol_type how));
 249 PROTO (boolean, NAME(aout,close_and_cleanup), (bfd *abfd));
 250 PROTO (boolean, NAME(aout,find_nearest_line), (bfd *abfd, asection *section,
 251       asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
 252       CONST char **functionname_ptr, unsigned int *line_ptr));
 253 PROTO (int,     NAME(aout,sizeof_headers), (bfd *abfd, boolean exec));
 254
 255 PROTO (void,    NAME(aout,swap_exec_header_in), (bfd *abfd,
 256                          struct external_exec *raw_bytes, struct internal_exec *execp));
 257
 258 PROTO (void,    NAME(aout,swap_exec_header_out),(bfd *abfd, struct internal_exec *execp,
 259                          struct external_exec *raw_bytes));
 260
 261 /* Prototypes for functions in stab-syms.c. */
 262
 263 PROTO(char *, aout_stab_name, (int code));
 264
 265 /* A.out uses the generic versions of these routines... */
 266
 267 #define aout_32_get_section_contents    bfd_generic_get_section_contents
 268 #define aout_32_close_and_cleanup       bfd_generic_close_and_cleanup
 269
 270 #define aout_64_get_section_contents    bfd_generic_get_section_contents
 271 #define aout_64_close_and_cleanup       bfd_generic_close_and_cleanup
 272 #ifndef NO_WRITE_HEADER_KLUDGE
 273 #define NO_WRITE_HEADER_KLUDGE 0
 274 #endif
 275
 276 #ifndef WRITE_HEADERS
 277 #define WRITE_HEADERS(abfd, execp)                                            \
 278       {                                                                       \
 279         bfd_size_type text_size; /* dummy vars */                             \
 280         file_ptr text_end;                                                    \
 281         if (adata(abfd).magic == undecided_magic)                             \
 282           NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end);     \
 283                                                                               \
 284         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
 285         execp->a_entry = bfd_get_start_address (abfd);                        \
 286                                                                               \
 287         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
 288                            obj_reloc_entry_size (abfd));                      \
 289         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
 290                            obj_reloc_entry_size (abfd));                      \
 291         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
 292                                                                               \
 293         bfd_seek (abfd, (file_ptr) 0, SEEK_SET);                              \
 294         bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd);              \
 295         /* Now write out reloc info, followed by syms and strings */          \
 296                                                                               \
 297         if (bfd_get_symcount (abfd) != 0)                                     \
 298             {                                                                 \
 299               bfd_seek (abfd, (file_ptr)(N_SYMOFF(*execp)), SEEK_SET);        \
 300                                                                               \
 301               NAME(aout,write_syms)(abfd);                                    \
 302                                                                               \
 303               bfd_seek (abfd, (file_ptr)(N_TRELOFF(*execp)), SEEK_SET);       \
 304                                                                               \
 305               if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd))) return false; \
 306               bfd_seek (abfd, (file_ptr)(N_DRELOFF(*execp)), SEEK_SET);       \
 307                                                                               \
 308               if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd))) return false; \
 309             }                                                                 \
 310       }
 311 #endif