include/aout/aout64.h

   1 /* `a.out' object-file definitions, including extensions to 64-bit fields */
   2
   3 #ifndef __A_OUT_64_H__
   4 #define __A_OUT_64_H__
   5
   6 /* This is the layout on disk of the 32-bit or 64-bit exec header. */
   7
   8 #ifndef external_exec
   9 struct external_exec
  10 {
  11   bfd_byte e_info[4];           /* magic number and stuff               */
  12   bfd_byte e_text[BYTES_IN_WORD]; /* length of text section in bytes    */
  13   bfd_byte e_data[BYTES_IN_WORD]; /* length of data section in bytes    */
  14   bfd_byte e_bss[BYTES_IN_WORD]; /* length of bss area in bytes                 */
  15   bfd_byte e_syms[BYTES_IN_WORD]; /* length of symbol table in bytes    */
  16   bfd_byte e_entry[BYTES_IN_WORD]; /* start address                     */
  17   bfd_byte e_trsize[BYTES_IN_WORD]; /* length of text relocation info   */
  18   bfd_byte e_drsize[BYTES_IN_WORD]; /* length of data relocation info   */
  19 };
  20
  21 #define EXEC_BYTES_SIZE (4 + BYTES_IN_WORD * 7)
  22
  23 /* Magic numbers for a.out files */
  24
  25 #if ARCH_SIZE==64
  26 #define OMAGIC 0x1001           /* Code indicating object file  */
  27 #define ZMAGIC 0x1002           /* Code indicating demand-paged executable.  */
  28 #define NMAGIC 0x1003           /* Code indicating pure executable.  */
  29
  30 /* There is no 64-bit QMAGIC as far as I know.  */
  31
  32 #define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
  33                         && N_MAGIC(x) != NMAGIC         \
  34                         && N_MAGIC(x) != ZMAGIC)
  35 #else
  36 #define OMAGIC 0407             /* ...object file or impure executable.  */
  37 #define NMAGIC 0410             /* Code indicating pure executable.  */
  38 #define ZMAGIC 0413             /* Code indicating demand-paged executable.  */
  39
  40 /* This indicates a demand-paged executable with the header in the text.
  41    As far as I know it is only used by 386BSD and/or BSDI.  */
  42 #define QMAGIC 0314
  43 #define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
  44                         && N_MAGIC(x) != NMAGIC         \
  45                         && N_MAGIC(x) != ZMAGIC \
  46                         && N_MAGIC(x) != QMAGIC)
  47 #endif
  48
  49 #endif
  50
  51 #ifdef QMAGIC
  52 #define N_IS_QMAGIC(x) (N_MAGIC (x) == QMAGIC)
  53 #else
  54 #define N_IS_QMAGIC(x) (0)
  55 #endif
  56
  57 /* The difference between PAGE_SIZE and N_SEGSIZE is that PAGE_SIZE is
  58    the the finest granularity at which you can page something, thus it
  59    controls the padding (if any) before the text segment of a ZMAGIC
  60    file.  N_SEGSIZE is the resolution at which things can be marked as
  61    read-only versus read/write, so it controls the padding between the
  62    text segment and the data segment.  These are the same for most
  63    machines, but different for sun3.  */
  64
  65 /* By default, segment size is constant.  But some machines override this
  66    to be a function of the a.out header (e.g. machine type).  */
  67
  68 #ifndef N_SEGSIZE
  69 #define N_SEGSIZE(x)    SEGMENT_SIZE
  70 #endif
  71 \f
  72 /* Virtual memory address of the text section.
  73    This is getting very complicated.  A good reason to discard a.out format
  74    for something that specifies these fields explicitly.  But til then...
  75
  76    * OMAGIC and NMAGIC files:
  77        (object files: text for "relocatable addr 0" right after the header)
  78        start at 0, offset is EXEC_BYTES_SIZE, size as stated.
  79    * The text address, offset, and size of ZMAGIC files depend
  80      on the entry point of the file:
  81      * entry point below TEXT_START_ADDR:
  82        (hack for SunOS shared libraries)
  83        start at 0, offset is 0, size as stated.
  84      * If N_HEADER_IN_TEXT(x) is true (which defaults to being the
  85        case when the entry point is EXEC_BYTES_SIZE or further into a page):
  86        no padding is needed; text can start after exec header.  Sun
  87        considers the text segment of such files to include the exec header;
  88        for BFD's purposes, we don't, which makes more work for us.
  89        start at TEXT_START_ADDR + EXEC_BYTES_SIZE, offset is EXEC_BYTES_SIZE,
  90        size as stated minus EXEC_BYTES_SIZE.
  91      * If N_HEADER_IN_TEXT(x) is false (which defaults to being the case when
  92        the entry point is less than EXEC_BYTES_SIZE into a page (e.g. page
  93        aligned)): (padding is needed so that text can start at a page boundary)
  94        start at TEXT_START_ADDR, offset PAGE_SIZE, size as stated.
  95
  96     Specific configurations may want to hardwire N_HEADER_IN_TEXT,
  97     for efficiency or to allow people to play games with the entry point.
  98     In that case, you would #define N_HEADER_IN_TEXT(x) as 1 for sunos,
  99     and as 0 for most other hosts (Sony News, Vax Ultrix, etc).
 100     (Do this in the appropriate bfd target file.)
 101     (The default is a heuristic that will break if people try changing
 102     the entry point, perhaps with the ld -e flag.)
 103
 104     * QMAGIC is always like a ZMAGIC for which N_HEADER_IN_TEXT is true,
 105     and for which the starting address is PAGE_SIZE (or should this be
 106     SEGMENT_SIZE?) (TEXT_START_ADDR only applies to ZMAGIC, not to QMAGIC).
 107     */
 108
 109 /* This macro is only relevant for ZMAGIC files; QMAGIC always has the header
 110    in the text.  */
 111 #ifndef N_HEADER_IN_TEXT
 112 #define N_HEADER_IN_TEXT(x) (((x).a_entry & (PAGE_SIZE-1)) >= EXEC_BYTES_SIZE)
 113 #endif
 114
 115 /* Sun shared libraries, not linux.  This macro is only relevant for ZMAGIC
 116    files.  */
 117 #ifndef N_SHARED_LIB
 118 #define N_SHARED_LIB(x) ((x).a_entry < TEXT_START_ADDR)
 119 #endif
 120
 121 #ifndef N_TXTADDR
 122 #define N_TXTADDR(x) \
 123     (/* The address of a QMAGIC file is always one page in, */ \
 124      /* with the header in the text.  */ \
 125      N_IS_QMAGIC (x) ? PAGE_SIZE + EXEC_BYTES_SIZE : \
 126      N_MAGIC(x) != ZMAGIC ? 0 : /* object file or NMAGIC */\
 127      N_SHARED_LIB(x) ? 0 :      \
 128      N_HEADER_IN_TEXT(x)  ?     \
 129             TEXT_START_ADDR + EXEC_BYTES_SIZE : /* no padding */\
 130             TEXT_START_ADDR                     /* a page of padding */\
 131     )
 132 #endif
 133
 134 /* Offset in an a.out of the start of the text section. */
 135 #ifndef N_TXTOFF
 136 #define N_TXTOFF(x)     \
 137     (/* For {O,N,Q}MAGIC, no padding.  */ \
 138      N_MAGIC(x) != ZMAGIC ? EXEC_BYTES_SIZE : \
 139      N_SHARED_LIB(x) ? 0 : \
 140      N_HEADER_IN_TEXT(x) ?      \
 141             EXEC_BYTES_SIZE :                   /* no padding */\
 142             PAGE_SIZE                           /* a page of padding */\
 143     )
 144 #endif
 145 /* Size of the text section.  It's always as stated, except that we
 146    offset it to `undo' the adjustment to N_TXTADDR and N_TXTOFF
 147    for ZMAGIC files that nominally include the exec header
 148    as part of the first page of text.  (BFD doesn't consider the
 149    exec header to be part of the text segment.)  */
 150 #ifndef N_TXTSIZE
 151 #define N_TXTSIZE(x) \
 152     (/* For QMAGIC, we don't consider the header part of the text section.  */\
 153      N_IS_QMAGIC (x) ? (x).a_text - EXEC_BYTES_SIZE : \
 154      (N_MAGIC(x) != ZMAGIC || N_SHARED_LIB(x)) ? (x).a_text : \
 155      N_HEADER_IN_TEXT(x)  ?     \
 156             (x).a_text - EXEC_BYTES_SIZE:       /* no padding */\
 157             (x).a_text                          /* a page of padding */\
 158     )
 159 #endif
 160 /* The address of the data segment in virtual memory.
 161    It is the text segment address, plus text segment size, rounded
 162    up to a N_SEGSIZE boundary for pure or pageable files. */
 163 #ifndef N_DATADDR
 164 #define N_DATADDR(x) \
 165     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+N_TXTSIZE(x)) \
 166      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+N_TXTSIZE(x)-1) & ~(N_SEGSIZE(x)-1))))
 167 #endif
 168 /* The address of the BSS segment -- immediately after the data segment.  */
 169
 170 #define N_BSSADDR(x)    (N_DATADDR(x) + (x).a_data)
 171
 172 /* Offsets of the various portions of the file after the text segment.  */
 173
 174 /* For {N,Q,Z}MAGIC, there is padding to make the data segment start
 175    on a page boundary.  Most of the time the a_text field (and thus
 176    N_TXTSIZE) already contains this padding.  But if it doesn't (I
 177    think maybe this happens on BSDI and/or 386BSD), then add it.  */
 178
 179 #ifndef N_DATOFF
 180 #define N_DATOFF(x) \
 181  (N_MAGIC(x) == OMAGIC ? N_TXTOFF(x) + N_TXTSIZE(x) : \
 182   N_SEGSIZE(x) + ((N_TXTOFF(x) + N_TXTSIZE(x) - 1) & ~(N_SEGSIZE(x) - 1)))
 183 #endif
 184
 185 #ifndef N_TRELOFF
 186 #define N_TRELOFF(x)    ( N_DATOFF(x) + (x).a_data )
 187 #endif
 188 #ifndef N_DRELOFF
 189 #define N_DRELOFF(x)    ( N_TRELOFF(x) + (x).a_trsize )
 190 #endif
 191 #ifndef N_SYMOFF
 192 #define N_SYMOFF(x)     ( N_DRELOFF(x) + (x).a_drsize )
 193 #endif
 194 #ifndef N_STROFF
 195 #define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
 196 #endif
 197 \f
 198 /* Symbols */
 199 #ifndef external_nlist
 200 struct external_nlist {
 201   bfd_byte e_strx[BYTES_IN_WORD];       /* index into string table of name */
 202   bfd_byte e_type[1];                   /* type of symbol */
 203   bfd_byte e_other[1];                  /* misc info (usually empty) */
 204   bfd_byte e_desc[2];                   /* description field */
 205   bfd_byte e_value[BYTES_IN_WORD];      /* value of symbol */
 206 };
 207 #define EXTERNAL_NLIST_SIZE (BYTES_IN_WORD+4+BYTES_IN_WORD)
 208 #endif
 209
 210 struct internal_nlist {
 211   unsigned long n_strx;                 /* index into string table of name */
 212   unsigned char n_type;                 /* type of symbol */
 213   unsigned char n_other;                /* misc info (usually empty) */
 214   unsigned short n_desc;                /* description field */
 215   bfd_vma n_value;                      /* value of symbol */
 216 };
 217
 218 /* The n_type field is the symbol type, containing:  */
 219
 220 #define N_UNDF  0       /* Undefined symbol */
 221 #define N_ABS   2       /* Absolute symbol -- defined at particular addr */
 222 #define N_TEXT  4       /* Text sym -- defined at offset in text seg */
 223 #define N_DATA  6       /* Data sym -- defined at offset in data seg */
 224 #define N_BSS   8       /* BSS  sym -- defined at offset in zero'd seg */
 225 #define N_COMM  0x12    /* Common symbol (visible after shared lib dynlink) */
 226 #define N_FN    0x1f    /* File name of .o file */
 227 #define N_FN_SEQ 0x0C   /* N_FN from Sequent compilers (sigh) */
 228 /* Note: N_EXT can only be usefully OR-ed with N_UNDF, N_ABS, N_TEXT,
 229    N_DATA, or N_BSS.  When the low-order bit of other types is set,
 230    (e.g. N_WARNING versus N_FN), they are two different types.  */
 231 #define N_EXT   1       /* External symbol (as opposed to local-to-this-file) */
 232 #define N_TYPE  0x1e
 233 #define N_STAB  0xe0    /* If any of these bits are on, it's a debug symbol */
 234
 235 #define N_INDR 0x0a
 236
 237 /* The following symbols refer to set elements.
 238    All the N_SET[ATDB] symbols with the same name form one set.
 239    Space is allocated for the set in the text section, and each set
 240    elements value is stored into one word of the space.
 241    The first word of the space is the length of the set (number of elements).
 242
 243    The address of the set is made into an N_SETV symbol
 244    whose name is the same as the name of the set.
 245    This symbol acts like a N_DATA global symbol
 246    in that it can satisfy undefined external references.  */
 247
 248 /* These appear as input to LD, in a .o file.  */
 249 #define N_SETA  0x14            /* Absolute set element symbol */
 250 #define N_SETT  0x16            /* Text set element symbol */
 251 #define N_SETD  0x18            /* Data set element symbol */
 252 #define N_SETB  0x1A            /* Bss set element symbol */
 253
 254 /* This is output from LD.  */
 255 #define N_SETV  0x1C            /* Pointer to set vector in data area.  */
 256
 257 /* Warning symbol. The text gives a warning message, the next symbol
 258    in the table will be undefined. When the symbol is referenced, the
 259    message is printed.  */
 260
 261 #define N_WARNING 0x1e
 262
 263 /* Relocations
 264
 265   There are two types of relocation flavours for a.out systems,
 266   standard and extended. The standard form is used on systems where the
 267   instruction has room for all the bits of an offset to the operand, whilst
 268   the extended form is used when an address operand has to be split over n
 269   instructions. Eg, on the 68k, each move instruction can reference
 270   the target with a displacement of 16 or 32 bits. On the sparc, move
 271   instructions use an offset of 14 bits, so the offset is stored in
 272   the reloc field, and the data in the section is ignored.
 273 */
 274
 275 /* This structure describes a single relocation to be performed.
 276    The text-relocation section of the file is a vector of these structures,
 277    all of which apply to the text section.
 278    Likewise, the data-relocation section applies to the data section.  */
 279
 280 struct reloc_std_external {
 281   bfd_byte      r_address[BYTES_IN_WORD];       /* offset of of data to relocate        */
 282   bfd_byte r_index[3];  /* symbol table index of symbol         */
 283   bfd_byte r_type[1];   /* relocation type                      */
 284 };
 285
 286 #define RELOC_STD_BITS_PCREL_BIG        0x80
 287 #define RELOC_STD_BITS_PCREL_LITTLE     0x01
 288
 289 #define RELOC_STD_BITS_LENGTH_BIG       0x60
 290 #define RELOC_STD_BITS_LENGTH_SH_BIG    5       /* To shift to units place */
 291 #define RELOC_STD_BITS_LENGTH_LITTLE    0x06
 292 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
 293
 294 #define RELOC_STD_BITS_EXTERN_BIG       0x10
 295 #define RELOC_STD_BITS_EXTERN_LITTLE    0x08
 296
 297 #define RELOC_STD_BITS_BASEREL_BIG      0x08
 298 #define RELOC_STD_BITS_BASEREL_LITTLE   0x08
 299
 300 #define RELOC_STD_BITS_JMPTABLE_BIG     0x04
 301 #define RELOC_STD_BITS_JMPTABLE_LITTLE  0x04
 302
 303 #define RELOC_STD_BITS_RELATIVE_BIG     0x02
 304 #define RELOC_STD_BITS_RELATIVE_LITTLE  0x02
 305
 306 #define RELOC_STD_SIZE  (BYTES_IN_WORD + 3 + 1)         /* Bytes per relocation entry */
 307
 308 struct reloc_std_internal
 309 {
 310   bfd_vma r_address;            /* Address (within segment) to be relocated.  */
 311   /* The meaning of r_symbolnum depends on r_extern.  */
 312   unsigned int r_symbolnum:24;
 313   /* Nonzero means value is a pc-relative offset
 314      and it should be relocated for changes in its own address
 315      as well as for changes in the symbol or section specified.  */
 316   unsigned int r_pcrel:1;
 317   /* Length (as exponent of 2) of the field to be relocated.
 318      Thus, a value of 2 indicates 1<<2 bytes.  */
 319   unsigned int r_length:2;
 320   /* 1 => relocate with value of symbol.
 321      r_symbolnum is the index of the symbol
 322      in files the symbol table.
 323      0 => relocate with the address of a segment.
 324      r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
 325      (the N_EXT bit may be set also, but signifies nothing).  */
 326   unsigned int r_extern:1;
 327   /* The next three bits are for SunOS shared libraries, and seem to
 328      be undocumented.  */
 329   unsigned int r_baserel:1;     /* Linkage table relative */
 330   unsigned int r_jmptable:1;    /* pc-relative to jump table */
 331   unsigned int r_relative:1;    /* "relative relocation" */
 332   /* unused */
 333   unsigned int r_pad:1;         /* Padding -- set to zero */
 334 };
 335
 336
 337 /* EXTENDED RELOCS  */
 338
 339 struct reloc_ext_external {
 340   bfd_byte r_address[BYTES_IN_WORD];    /* offset of of data to relocate        */
 341   bfd_byte r_index[3];  /* symbol table index of symbol         */
 342   bfd_byte r_type[1];   /* relocation type                      */
 343   bfd_byte r_addend[BYTES_IN_WORD];     /* datum addend                         */
 344 };
 345
 346 #define RELOC_EXT_BITS_EXTERN_BIG       0x80
 347 #define RELOC_EXT_BITS_EXTERN_LITTLE    0x01
 348
 349 #define RELOC_EXT_BITS_TYPE_BIG         0x1F
 350 #define RELOC_EXT_BITS_TYPE_SH_BIG      0
 351 #define RELOC_EXT_BITS_TYPE_LITTLE      0xF8
 352 #define RELOC_EXT_BITS_TYPE_SH_LITTLE   3
 353
 354 /* Bytes per relocation entry */
 355 #define RELOC_EXT_SIZE  (BYTES_IN_WORD + 3 + 1 + BYTES_IN_WORD)
 356
 357 enum reloc_type
 358 {
 359   /* simple relocations */
 360   RELOC_8,                      /* data[0:7] = addend + sv              */
 361   RELOC_16,                     /* data[0:15] = addend + sv             */
 362   RELOC_32,                     /* data[0:31] = addend + sv             */
 363   /* pc-rel displacement */
 364   RELOC_DISP8,                  /* data[0:7] = addend - pc + sv         */
 365   RELOC_DISP16,                 /* data[0:15] = addend - pc + sv        */
 366   RELOC_DISP32,                 /* data[0:31] = addend - pc + sv        */
 367   /* Special */
 368   RELOC_WDISP30,                /* data[0:29] = (addend + sv - pc)>>2   */
 369   RELOC_WDISP22,                /* data[0:21] = (addend + sv - pc)>>2   */
 370   RELOC_HI22,                   /* data[0:21] = (addend + sv)>>10       */
 371   RELOC_22,                     /* data[0:21] = (addend + sv)           */
 372   RELOC_13,                     /* data[0:12] = (addend + sv)           */
 373   RELOC_LO10,                   /* data[0:9] = (addend + sv)            */
 374   RELOC_SFA_BASE,
 375   RELOC_SFA_OFF13,
 376   /* P.I.C. (base-relative) */
 377   RELOC_BASE10,                 /* Not sure - maybe we can do this the */
 378   RELOC_BASE13,                 /* right way now */
 379   RELOC_BASE22,
 380   /* for some sort of pc-rel P.I.C. (?) */
 381   RELOC_PC10,
 382   RELOC_PC22,
 383   /* P.I.C. jump table */
 384   RELOC_JMP_TBL,
 385   /* reputedly for shared libraries somehow */
 386   RELOC_SEGOFF16,
 387   RELOC_GLOB_DAT,
 388   RELOC_JMP_SLOT,
 389   RELOC_RELATIVE,
 390
 391   RELOC_11,
 392   RELOC_WDISP2_14,
 393   RELOC_WDISP19,
 394   RELOC_HHI22,                  /* data[0:21] = (addend + sv) >> 42     */
 395   RELOC_HLO10,                  /* data[0:9] = (addend + sv) >> 32      */
 396
 397   /* 29K relocation types */
 398   RELOC_JUMPTARG,
 399   RELOC_CONST,
 400   RELOC_CONSTH,
 401
 402   /* All the new ones I can think of *//*v9*/
 403
 404   RELOC_64,                     /* data[0:63] = addend + sv             *//*v9*/
 405   RELOC_DISP64,                 /* data[0:63] = addend - pc + sv        *//*v9*/
 406   RELOC_WDISP21,                /* data[0:20] = (addend + sv - pc)>>2   *//*v9*/
 407   RELOC_DISP21,                 /* data[0:20] = addend - pc + sv        *//*v9*/
 408   RELOC_DISP14,                 /* data[0:13] = addend - pc + sv        *//*v9*/
 409   /* Q .
 410      What are the other ones,
 411      Since this is a clean slate, can we throw away the ones we dont
 412      understand ? Should we sort the values ? What about using a
 413      microcode format like the 68k ?
 414      */
 415   NO_RELOC
 416   };
 417
 418
 419 struct reloc_internal {
 420   bfd_vma r_address;            /* offset of of data to relocate        */
 421   long  r_index;                /* symbol table index of symbol         */
 422   enum reloc_type r_type;       /* relocation type                      */
 423   bfd_vma r_addend;             /* datum addend                         */
 424 };
 425
 426 /* Q.
 427    Should the length of the string table be 4 bytes or 8 bytes ?
 428
 429    Q.
 430    What about archive indexes ?
 431
 432  */
 433
 434 #endif                          /* __A_OUT_64_H__ */