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