gas/config/aout_gnu.h

   1 /* This file is aout_gnu.h
   2
   3    Copyright 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 2000, 2002
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GAS, the GNU Assembler.
   7
   8    GAS is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2, or (at your option)
  11    any later version.
  12
  13    GAS is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with GAS; see the file COPYING.  If not, write to
  20    the Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
  21
  22 #ifndef __A_OUT_GNU_H__
  23 #define __A_OUT_GNU_H__
  24
  25 /* There are two main flavours of a.out, one which uses the standard
  26    relocations, and one which uses extended relocations.
  27
  28    Today, the extended reloc uses are
  29    TC_SPARC
  30
  31    each must define the enum reloc_type
  32
  33 */
  34
  35 #define USE_EXTENDED_RELOC defined(TC_SPARC)
  36
  37 #if defined(TC_SPARC)
  38 enum reloc_type
  39   {
  40     RELOC_8, RELOC_16, RELOC_32,/* simple relocations */
  41     RELOC_DISP8, RELOC_DISP16, RELOC_DISP32,    /* pc-rel displacement */
  42     RELOC_WDISP30, RELOC_WDISP22,
  43     RELOC_HI22, RELOC_22,
  44     RELOC_13, RELOC_LO10,
  45     RELOC_SFA_BASE, RELOC_SFA_OFF13,
  46     RELOC_BASE10, RELOC_BASE13, RELOC_BASE22,   /* P.I.C. (base-relative) */
  47     RELOC_PC10, RELOC_PC22,     /* for some sort of pc-rel P.I.C. (?) */
  48     RELOC_JMP_TBL,              /* P.I.C. jump table */
  49     RELOC_SEGOFF16,             /* reputedly for shared libraries somehow */
  50     RELOC_GLOB_DAT, RELOC_JMP_SLOT, RELOC_RELATIVE,
  51     RELOC_10, RELOC_11,
  52     RELOC_WDISP2_14,
  53     RELOC_WDISP19,
  54     RELOC_HHI22,
  55     RELOC_HLO10,
  56
  57     /* 29K relocation types */
  58     RELOC_JUMPTARG, RELOC_CONST, RELOC_CONSTH,
  59
  60     RELOC_WDISP14, RELOC_WDISP21,
  61
  62     NO_RELOC
  63   };
  64
  65 #endif /* TC_SPARC */
  66
  67 #define __GNU_EXEC_MACROS__
  68
  69 #ifndef __STRUCT_EXEC_OVERRIDE__
  70
  71 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
  72    "struct exec".  Don't assume that on this machine, the "struct exec"
  73    will lay out the same sizes or alignments.  */
  74
  75 struct exec_bytes
  76   {
  77     unsigned char a_info[4];
  78     unsigned char a_text[4];
  79     unsigned char a_data[4];
  80     unsigned char a_bss[4];
  81     unsigned char a_syms[4];
  82     unsigned char a_entry[4];
  83     unsigned char a_trsize[4];
  84     unsigned char a_drsize[4];
  85   };
  86
  87 /* How big the "struct exec" is on disk */
  88 #define EXEC_BYTES_SIZE (8 * 4)
  89
  90 /* This is the layout in memory of a "struct exec" while we process it.  */
  91
  92 struct exec
  93 {
  94   unsigned long a_info;         /* Use macros N_MAGIC, etc for access */
  95   unsigned a_text;              /* length of text, in bytes */
  96   unsigned a_data;              /* length of data, in bytes */
  97   unsigned a_bss;               /* length of uninitialized data area for file, in bytes */
  98   unsigned a_syms;              /* length of symbol table data in file, in bytes */
  99   unsigned a_entry;             /* start address */
 100   unsigned a_trsize;            /* length of relocation info for text, in bytes */
 101   unsigned a_drsize;            /* length of relocation info for data, in bytes */
 102 };
 103
 104 #endif /* __STRUCT_EXEC_OVERRIDE__ */
 105
 106 /* these go in the N_MACHTYPE field */
 107 /* These symbols could be defined by code from Suns...punt 'em */
 108 #undef M_UNKNOWN
 109 #undef M_68010
 110 #undef M_68020
 111 #undef M_SPARC
 112 enum machine_type
 113   {
 114     M_UNKNOWN = 0,
 115     M_68010 = 1,
 116     M_68020 = 2,
 117     M_SPARC = 3,
 118     /* skip a bunch so we don't run into any of sun's numbers */
 119     M_386 = 100,
 120     M_29K = 101,
 121     M_RS6000 = 102,             /* IBM RS/6000 */
 122     M_VAX4K_NETBSD = 150,
 123     /* HP/BSD formats */
 124     M_HP200 = 200,              /* hp200 (68010) BSD binary */
 125     M_HP300 = 300,              /* hp300 (68020+68881) BSD binary */
 126     M_HPUX23 = 0x020C           /* hp200/300 HPUX binary */
 127   };
 128
 129 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
 130 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 131 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 132 #define N_SET_INFO(exec, magic, type, flags) \
 133     ((exec).a_info = ((magic) & 0xffff) \
 134      | (((int)(type) & 0xff) << 16) \
 135      | (((flags) & 0xff) << 24))
 136 #define N_SET_MAGIC(exec, magic) \
 137     ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 138
 139 #define N_SET_MACHTYPE(exec, machtype) \
 140     ((exec).a_info = \
 141      ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 142
 143 #define N_SET_FLAGS(exec, flags) \
 144     ((exec).a_info = \
 145      ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 146
 147 /* Code indicating object file or impure executable.  */
 148 #ifndef OMAGIC
 149 #define OMAGIC 0407
 150 #endif
 151 /* Code indicating pure executable.  */
 152 #define NMAGIC 0410
 153 /* Code indicating demand-paged executable.  */
 154 #define ZMAGIC 0413
 155
 156 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
 157    (almost always "unlinked .o's" these days), should be zero.
 158    For linked files, should reflect reality if we know it.  */
 159
 160 #ifndef N_TXTADDR
 161 #define N_TXTADDR(x)    (N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
 162 #endif
 163
 164 #ifndef N_BADMAG
 165 #define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
 166                            && N_MAGIC(x) != NMAGIC              \
 167                            && N_MAGIC(x) != ZMAGIC)
 168 #endif
 169
 170 /* By default, segment size is constant.  But on some machines, it can
 171    be a function of the a.out header (e.g. machine type).  */
 172 #ifndef N_SEGSIZE
 173 #define N_SEGSIZE(x)    SEGMENT_SIZE
 174 #endif
 175
 176 /* This complexity is for encapsulated COFF support */
 177 #ifndef _N_HDROFF
 178 #define _N_HDROFF(x)    (N_SEGSIZE(x) - sizeof (struct exec))
 179 #endif
 180
 181 #ifndef N_TXTOFF
 182 #define N_TXTOFF(x)     (N_MAGIC(x) == ZMAGIC ? \
 183                          _N_HDROFF((x)) + sizeof (struct exec) :        \
 184                          sizeof (struct exec))
 185 #endif
 186
 187 #ifndef N_DATOFF
 188 #define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text )
 189 #endif
 190
 191 #ifndef N_TRELOFF
 192 #define N_TRELOFF(x)    ( N_DATOFF(x) + (x).a_data )
 193 #endif
 194
 195 #ifndef N_DRELOFF
 196 #define N_DRELOFF(x)    ( N_TRELOFF(x) + (x).a_trsize )
 197 #endif
 198
 199 #ifndef N_SYMOFF
 200 #define N_SYMOFF(x)     ( N_DRELOFF(x) + (x).a_drsize )
 201 #endif
 202
 203 #ifndef N_STROFF
 204 #define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
 205 #endif
 206
 207 /* Address of text segment in memory after it is loaded.  */
 208 #ifndef N_TXTADDR
 209 #define N_TXTADDR(x)    0
 210 #endif
 211
 212 #ifndef N_DATADDR
 213 #define N_DATADDR(x) \
 214     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
 215      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x).a_text-1) & ~(N_SEGSIZE(x)-1))))
 216 #endif
 217
 218 /* Address of bss segment in memory after it is loaded.  */
 219 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
 220 \f
 221 struct nlist
 222   {
 223     union
 224       {
 225         char *n_name;
 226         struct nlist *n_next;
 227         long n_strx;
 228       }
 229     n_un;
 230     unsigned char n_type;
 231     char n_other;
 232     short n_desc;
 233     unsigned long n_value;
 234   };
 235
 236 #define N_UNDF 0
 237 #define N_ABS 2
 238 #define N_TEXT 4
 239 #define N_DATA 6
 240 #define N_BSS 8
 241 #define N_COMM  0x12            /* common (visible in shared lib commons) */
 242 #define N_FN 0x1F               /* File name of a .o file */
 243
 244 /* Note: N_EXT can only usefully be OR-ed with N_UNDF, N_ABS, N_TEXT,
 245    N_DATA, or N_BSS.  When the low-order bit of other types is set,
 246    (e.g. N_WARNING versus N_FN), they are two different types.  */
 247 #define N_EXT 1
 248 #define N_TYPE 036
 249 #define N_STAB 0340
 250
 251 /* The following type indicates the definition of a symbol as being
 252    an indirect reference to another symbol.  The other symbol
 253    appears as an undefined reference, immediately following this symbol.
 254
 255    Indirection is asymmetrical.  The other symbol's value will be used
 256    to satisfy requests for the indirect symbol, but not vice versa.
 257    If the other symbol does not have a definition, libraries will
 258    be searched to find a definition.  */
 259
 260 #define N_INDR 0xa
 261
 262 /* The following symbols refer to set elements.
 263    All the N_SET[ATDB] symbols with the same name form one set.
 264    Space is allocated for the set in the text section, and each set
 265    element's value is stored into one word of the space.
 266    The first word of the space is the length of the set (number of elements).
 267
 268    The address of the set is made into an N_SETV symbol
 269    whose name is the same as the name of the set.
 270    This symbol acts like a N_DATA global symbol
 271    in that it can satisfy undefined external references.  */
 272
 273 /* These appear as input to LD, in a .o file.  */
 274 #define N_SETA  0x14            /* Absolute set element symbol */
 275 #define N_SETT  0x16            /* Text set element symbol */
 276 #define N_SETD  0x18            /* Data set element symbol */
 277 #define N_SETB  0x1A            /* Bss set element symbol */
 278
 279 /* This is output from LD.  */
 280 #define N_SETV  0x1C            /* Pointer to set vector in data area.  */
 281
 282 /* Warning symbol. The text gives a warning message, the next symbol
 283    in the table will be undefined. When the symbol is referenced, the
 284    message is printed.  */
 285
 286 #define N_WARNING 0x1e
 287
 288 /* Weak symbols.  These are a GNU extension to the a.out format.  The
 289    semantics are those of ELF weak symbols.  Weak symbols are always
 290    externally visible.  The N_WEAK? values are squeezed into the
 291    available slots.  The value of a N_WEAKU symbol is 0.  The values
 292    of the other types are the definitions.  */
 293 #define N_WEAKU 0x0d            /* Weak undefined symbol.  */
 294 #define N_WEAKA 0x0e            /* Weak absolute symbol.  */
 295 #define N_WEAKT 0x0f            /* Weak text symbol.  */
 296 #define N_WEAKD 0x10            /* Weak data symbol.  */
 297 #define N_WEAKB 0x11            /* Weak bss symbol.  */
 298 \f
 299 /* This structure describes a single relocation to be performed.
 300    The text-relocation section of the file is a vector of these structures,
 301    all of which apply to the text section.
 302    Likewise, the data-relocation section applies to the data section.  */
 303
 304 /* The following enum and struct were borrowed from SunOS's
 305    /usr/include/sun4/a.out.h  and extended to handle
 306    other machines.  It is currently used on SPARC and AMD 29000.
 307
 308    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
 309    how we might process it on a native host.  */
 310 #if USE_EXTENDED_RELOC
 311
 312 struct reloc_ext_bytes
 313   {
 314     unsigned char r_address[4];
 315     unsigned char r_index[3];
 316     unsigned char r_bits[1];
 317     unsigned char r_addend[4];
 318   };
 319
 320 #define RELOC_EXT_BITS_EXTERN_BIG       0x80
 321 #define RELOC_EXT_BITS_EXTERN_LITTLE    0x01
 322
 323 #define RELOC_EXT_BITS_TYPE_BIG         0x1F
 324 #define RELOC_EXT_BITS_TYPE_SH_BIG      0
 325 #define RELOC_EXT_BITS_TYPE_LITTLE      0xF8
 326 #define RELOC_EXT_BITS_TYPE_SH_LITTLE   3
 327
 328 #define RELOC_EXT_SIZE  12      /* Bytes per relocation entry */
 329
 330 struct reloc_info_extended
 331 {
 332   unsigned long r_address;
 333   unsigned int r_index:24;
 334 # define        r_symbolnum  r_index
 335   unsigned r_extern:1;
 336   unsigned:2;
 337   /*  RS/6000 compiler does not support enum bitfield
 338             enum reloc_type r_type:5; */
 339   enum reloc_type r_type;
 340   long int r_addend;
 341 };
 342
 343 #else
 344
 345 /* The standard, old-fashioned, Berkeley compatible relocation struct */
 346
 347 #ifdef TC_I860
 348 /* NOTE: three bits max, see struct reloc_info_i860.r_type */
 349 enum i860_reloc_type
 350   {
 351     NO_RELOC = 0, BRADDR, LOW0, LOW1, LOW2, LOW3, LOW4, SPLIT0, SPLIT1, SPLIT2, RELOC_32,
 352   };
 353
 354 typedef enum i860_reloc_type reloc_type;
 355
 356 /* NOTE: two bits max, see reloc_info_i860.r_type */
 357 enum highlow_type
 358   {
 359     NO_SPEC = 0, PAIR, HIGH, HIGHADJ,
 360   };
 361
 362 struct reloc_info_i860
 363 {
 364   unsigned long r_address;
 365   /*
 366          * Using bit fields here is a bad idea because the order is not portable. :-(
 367          */
 368   unsigned int r_symbolnum:24;
 369   unsigned int r_pcrel:1;
 370   unsigned int r_extern:1;
 371   /* combining the two field simplifies the argument passing in "new_fix()" */
 372   /* and is compatible with the existing Sparc #ifdef's */
 373   /* r_type:  highlow_type - bits 5,4; reloc_type - bits 3-0 */
 374   unsigned int r_type:6;
 375   long r_addend;
 376 };
 377
 378 #endif /* TC_I860 */
 379
 380 struct reloc_std_bytes
 381   {
 382     unsigned char r_address[4];
 383     unsigned char r_index[3];
 384     unsigned char r_bits[1];
 385   };
 386
 387 #define RELOC_STD_BITS_PCREL_BIG        0x80
 388 #define RELOC_STD_BITS_PCREL_LITTLE     0x01
 389
 390 #define RELOC_STD_BITS_LENGTH_BIG       0x60
 391 #define RELOC_STD_BITS_LENGTH_SH_BIG    5       /* To shift to units place */
 392 #define RELOC_STD_BITS_LENGTH_LITTLE    0x06
 393 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
 394
 395 #define RELOC_STD_BITS_EXTERN_BIG       0x10
 396 #define RELOC_STD_BITS_EXTERN_LITTLE    0x08
 397
 398 #define RELOC_STD_BITS_BASEREL_BIG      0x08
 399 #define RELOC_STD_BITS_BASEREL_LITTLE   0x08
 400
 401 #define RELOC_STD_BITS_JMPTABLE_BIG     0x04
 402 #define RELOC_STD_BITS_JMPTABLE_LITTLE  0x04
 403
 404 #define RELOC_STD_BITS_RELATIVE_BIG     0x02
 405 #define RELOC_STD_BITS_RELATIVE_LITTLE  0x02
 406
 407 #define RELOC_STD_SIZE  8       /* Bytes per relocation entry */
 408
 409 #endif /* USE_EXTENDED_RELOC */
 410
 411 #ifndef CUSTOM_RELOC_FORMAT
 412 struct relocation_info
 413 {
 414   /* Address (within segment) to be relocated.  */
 415   int r_address;
 416   /* The meaning of r_symbolnum depends on r_extern.  */
 417   unsigned int r_symbolnum:24;
 418   /* Nonzero means value is a pc-relative offset
 419            and it should be relocated for changes in its own address
 420            as well as for changes in the symbol or section specified.  */
 421   unsigned int r_pcrel:1;
 422   /* Length (as exponent of 2) of the field to be relocated.
 423            Thus, a value of 2 indicates 1<<2 bytes.  */
 424   unsigned int r_length:2;
 425   /* 1 => relocate with value of symbol.
 426            r_symbolnum is the index of the symbol
 427            in file's the symbol table.
 428            0 => relocate with the address of a segment.
 429            r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
 430            (the N_EXT bit may be set also, but signifies nothing).  */
 431   unsigned int r_extern:1;
 432   /* The next three bits are for SunOS shared libraries, and seem to
 433            be undocumented.  */
 434 #ifdef TC_NS32K
 435   unsigned int r_bsr:1;
 436   unsigned int r_disp:2;
 437 #else
 438   unsigned int r_baserel:1;     /* Linkage table relative */
 439   unsigned int r_jmptable:1;    /* pc-relative to jump table */
 440   unsigned int r_relative:1;    /* "relative relocation" */
 441 #endif /* TC_NS32K */
 442   /* unused */
 443   unsigned int r_pad:1;         /* Padding -- set to zero */
 444 };
 445
 446 #endif /* CUSTOM_RELOC_FORMAT */
 447
 448 #endif /* __A_OUT_GNU_H__ */
 449
 450 /* end of aout_gnu.h */