gas/config/aout_gnu.h

   1 /* This file is aout_gnu.h
   2
   3    Copyright 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 2000
   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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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, TC_A29K
  30
  31    each must define the enum reloc_type
  32
  33 */
  34
  35 #define USE_EXTENDED_RELOC (defined(TC_SPARC) || defined(TC_A29K))
  36
  37 #if defined(TC_SPARC) || defined(TC_A29K)
  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 or TC_A29K */
  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     /* HP/BSD formats */
 123     M_HP200 = 200,              /* hp200 (68010) BSD binary */
 124     M_HP300 = 300,              /* hp300 (68020+68881) BSD binary */
 125     M_HPUX23 = 0x020C           /* hp200/300 HPUX binary */
 126   };
 127
 128 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
 129 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 130 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 131 #define N_SET_INFO(exec, magic, type, flags) \
 132     ((exec).a_info = ((magic) & 0xffff) \
 133      | (((int)(type) & 0xff) << 16) \
 134      | (((flags) & 0xff) << 24))
 135 #define N_SET_MAGIC(exec, magic) \
 136     ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 137
 138 #define N_SET_MACHTYPE(exec, machtype) \
 139     ((exec).a_info = \
 140      ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 141
 142 #define N_SET_FLAGS(exec, flags) \
 143     ((exec).a_info = \
 144      ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 145
 146 /* Code indicating object file or impure executable.  */
 147 #ifndef OMAGIC
 148 #define OMAGIC 0407
 149 #endif
 150 /* Code indicating pure executable.  */
 151 #define NMAGIC 0410
 152 /* Code indicating demand-paged executable.  */
 153 #define ZMAGIC 0413
 154
 155 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
 156    (almost always "unlinked .o's" these days), should be zero.
 157    For linked files, should reflect reality if we know it.  */
 158
 159 #ifndef N_TXTADDR
 160 #define N_TXTADDR(x)    (N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
 161 #endif
 162
 163 #ifndef N_BADMAG
 164 #define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
 165                            && N_MAGIC(x) != NMAGIC              \
 166                            && N_MAGIC(x) != ZMAGIC)
 167 #endif
 168
 169 /* By default, segment size is constant.  But on some machines, it can
 170    be a function of the a.out header (e.g. machine type).  */
 171 #ifndef N_SEGSIZE
 172 #define N_SEGSIZE(x)    SEGMENT_SIZE
 173 #endif
 174
 175 /* This complexity is for encapsulated COFF support */
 176 #ifndef _N_HDROFF
 177 #define _N_HDROFF(x)    (N_SEGSIZE(x) - sizeof (struct exec))
 178 #endif
 179
 180 #ifndef N_TXTOFF
 181 #define N_TXTOFF(x)     (N_MAGIC(x) == ZMAGIC ? \
 182                          _N_HDROFF((x)) + sizeof (struct exec) :        \
 183                          sizeof (struct exec))
 184 #endif
 185
 186 #ifndef N_DATOFF
 187 #define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text )
 188 #endif
 189
 190 #ifndef N_TRELOFF
 191 #define N_TRELOFF(x)    ( N_DATOFF(x) + (x).a_data )
 192 #endif
 193
 194 #ifndef N_DRELOFF
 195 #define N_DRELOFF(x)    ( N_TRELOFF(x) + (x).a_trsize )
 196 #endif
 197
 198 #ifndef N_SYMOFF
 199 #define N_SYMOFF(x)     ( N_DRELOFF(x) + (x).a_drsize )
 200 #endif
 201
 202 #ifndef N_STROFF
 203 #define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
 204 #endif
 205
 206 /* Address of text segment in memory after it is loaded.  */
 207 #ifndef N_TXTADDR
 208 #define N_TXTADDR(x)    0
 209 #endif
 210
 211 #ifndef N_DATADDR
 212 #define N_DATADDR(x) \
 213     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
 214      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x).a_text-1) & ~(N_SEGSIZE(x)-1))))
 215 #endif
 216
 217 /* Address of bss segment in memory after it is loaded.  */
 218 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
 219 \f
 220 struct nlist
 221   {
 222     union
 223       {
 224         char *n_name;
 225         struct nlist *n_next;
 226         long n_strx;
 227       }
 228     n_un;
 229     unsigned char n_type;
 230     char n_other;
 231     short n_desc;
 232     unsigned long n_value;
 233   };
 234
 235 #define N_UNDF 0
 236 #define N_ABS 2
 237 #define N_TEXT 4
 238 #define N_DATA 6
 239 #define N_BSS 8
 240 #define N_COMM  0x12            /* common (visible in shared lib commons) */
 241 #define N_FN 0x1F               /* File name of a .o file */
 242
 243 /* Note: N_EXT can only usefully be OR-ed with N_UNDF, N_ABS, N_TEXT,
 244    N_DATA, or N_BSS.  When the low-order bit of other types is set,
 245    (e.g. N_WARNING versus N_FN), they are two different types.  */
 246 #define N_EXT 1
 247 #define N_TYPE 036
 248 #define N_STAB 0340
 249
 250 /* The following type indicates the definition of a symbol as being
 251    an indirect reference to another symbol.  The other symbol
 252    appears as an undefined reference, immediately following this symbol.
 253
 254    Indirection is asymmetrical.  The other symbol's value will be used
 255    to satisfy requests for the indirect symbol, but not vice versa.
 256    If the other symbol does not have a definition, libraries will
 257    be searched to find a definition.  */
 258
 259 #define N_INDR 0xa
 260
 261 /* The following symbols refer to set elements.
 262    All the N_SET[ATDB] symbols with the same name form one set.
 263    Space is allocated for the set in the text section, and each set
 264    element's value is stored into one word of the space.
 265    The first word of the space is the length of the set (number of elements).
 266
 267    The address of the set is made into an N_SETV symbol
 268    whose name is the same as the name of the set.
 269    This symbol acts like a N_DATA global symbol
 270    in that it can satisfy undefined external references.  */
 271
 272 /* These appear as input to LD, in a .o file.  */
 273 #define N_SETA  0x14            /* Absolute set element symbol */
 274 #define N_SETT  0x16            /* Text set element symbol */
 275 #define N_SETD  0x18            /* Data set element symbol */
 276 #define N_SETB  0x1A            /* Bss set element symbol */
 277
 278 /* This is output from LD.  */
 279 #define N_SETV  0x1C            /* Pointer to set vector in data area.  */
 280
 281 /* Warning symbol. The text gives a warning message, the next symbol
 282    in the table will be undefined. When the symbol is referenced, the
 283    message is printed.  */
 284
 285 #define N_WARNING 0x1e
 286
 287 /* Weak symbols.  These are a GNU extension to the a.out format.  The
 288    semantics are those of ELF weak symbols.  Weak symbols are always
 289    externally visible.  The N_WEAK? values are squeezed into the
 290    available slots.  The value of a N_WEAKU symbol is 0.  The values
 291    of the other types are the definitions.  */
 292 #define N_WEAKU 0x0d            /* Weak undefined symbol.  */
 293 #define N_WEAKA 0x0e            /* Weak absolute symbol.  */
 294 #define N_WEAKT 0x0f            /* Weak text symbol.  */
 295 #define N_WEAKD 0x10            /* Weak data symbol.  */
 296 #define N_WEAKB 0x11            /* Weak bss symbol.  */
 297 \f
 298 /* This structure describes a single relocation to be performed.
 299    The text-relocation section of the file is a vector of these structures,
 300    all of which apply to the text section.
 301    Likewise, the data-relocation section applies to the data section.  */
 302
 303 /* The following enum and struct were borrowed from SunOS's
 304    /usr/include/sun4/a.out.h  and extended to handle
 305    other machines.  It is currently used on SPARC and AMD 29000.
 306
 307    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
 308    how we might process it on a native host.  */
 309 #if USE_EXTENDED_RELOC
 310
 311 struct reloc_ext_bytes
 312   {
 313     unsigned char r_address[4];
 314     unsigned char r_index[3];
 315     unsigned char r_bits[1];
 316     unsigned char r_addend[4];
 317   };
 318
 319 #define RELOC_EXT_BITS_EXTERN_BIG       0x80
 320 #define RELOC_EXT_BITS_EXTERN_LITTLE    0x01
 321
 322 #define RELOC_EXT_BITS_TYPE_BIG         0x1F
 323 #define RELOC_EXT_BITS_TYPE_SH_BIG      0
 324 #define RELOC_EXT_BITS_TYPE_LITTLE      0xF8
 325 #define RELOC_EXT_BITS_TYPE_SH_LITTLE   3
 326
 327 #define RELOC_EXT_SIZE  12      /* Bytes per relocation entry */
 328
 329 struct reloc_info_extended
 330 {
 331   unsigned long r_address;
 332   unsigned int r_index:24;
 333 # define        r_symbolnum  r_index
 334   unsigned r_extern:1;
 335   unsigned:2;
 336   /*  RS/6000 compiler does not support enum bitfield
 337             enum reloc_type r_type:5; */
 338   enum reloc_type r_type;
 339   long int r_addend;
 340 };
 341
 342 #else
 343
 344 /* The standard, old-fashioned, Berkeley compatible relocation struct */
 345
 346 #ifdef TC_I860
 347 /* NOTE: three bits max, see struct reloc_info_i860.r_type */
 348 enum i860_reloc_type
 349   {
 350     NO_RELOC = 0, BRADDR, LOW0, LOW1, LOW2, LOW3, LOW4, SPLIT0, SPLIT1, SPLIT2, RELOC_32,
 351   };
 352
 353 typedef enum i860_reloc_type reloc_type;
 354
 355 /* NOTE: two bits max, see reloc_info_i860.r_type */
 356 enum highlow_type
 357   {
 358     NO_SPEC = 0, PAIR, HIGH, HIGHADJ,
 359   };
 360
 361 struct reloc_info_i860
 362 {
 363   unsigned long r_address;
 364   /*
 365          * Using bit fields here is a bad idea because the order is not portable. :-(
 366          */
 367   unsigned int r_symbolnum:24;
 368   unsigned int r_pcrel:1;
 369   unsigned int r_extern:1;
 370   /* combining the two field simplifies the argument passing in "new_fix()" */
 371   /* and is compatible with the existing Sparc #ifdef's */
 372   /* r_type:  highlow_type - bits 5,4; reloc_type - bits 3-0 */
 373   unsigned int r_type:6;
 374   long r_addend;
 375 };
 376
 377 #endif /* TC_I860 */
 378
 379 struct reloc_std_bytes
 380   {
 381     unsigned char r_address[4];
 382     unsigned char r_index[3];
 383     unsigned char r_bits[1];
 384   };
 385
 386 #define RELOC_STD_BITS_PCREL_BIG        0x80
 387 #define RELOC_STD_BITS_PCREL_LITTLE     0x01
 388
 389 #define RELOC_STD_BITS_LENGTH_BIG       0x60
 390 #define RELOC_STD_BITS_LENGTH_SH_BIG    5       /* To shift to units place */
 391 #define RELOC_STD_BITS_LENGTH_LITTLE    0x06
 392 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
 393
 394 #define RELOC_STD_BITS_EXTERN_BIG       0x10
 395 #define RELOC_STD_BITS_EXTERN_LITTLE    0x08
 396
 397 #define RELOC_STD_BITS_BASEREL_BIG      0x08
 398 #define RELOC_STD_BITS_BASEREL_LITTLE   0x08
 399
 400 #define RELOC_STD_BITS_JMPTABLE_BIG     0x04
 401 #define RELOC_STD_BITS_JMPTABLE_LITTLE  0x04
 402
 403 #define RELOC_STD_BITS_RELATIVE_BIG     0x02
 404 #define RELOC_STD_BITS_RELATIVE_LITTLE  0x02
 405
 406 #define RELOC_STD_SIZE  8       /* Bytes per relocation entry */
 407
 408 #endif /* USE_EXTENDED_RELOC */
 409
 410 #ifndef CUSTOM_RELOC_FORMAT
 411 struct relocation_info
 412 {
 413   /* Address (within segment) to be relocated.  */
 414   int r_address;
 415   /* The meaning of r_symbolnum depends on r_extern.  */
 416   unsigned int r_symbolnum:24;
 417   /* Nonzero means value is a pc-relative offset
 418            and it should be relocated for changes in its own address
 419            as well as for changes in the symbol or section specified.  */
 420   unsigned int r_pcrel:1;
 421   /* Length (as exponent of 2) of the field to be relocated.
 422            Thus, a value of 2 indicates 1<<2 bytes.  */
 423   unsigned int r_length:2;
 424   /* 1 => relocate with value of symbol.
 425            r_symbolnum is the index of the symbol
 426            in file's the symbol table.
 427            0 => relocate with the address of a segment.
 428            r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
 429            (the N_EXT bit may be set also, but signifies nothing).  */
 430   unsigned int r_extern:1;
 431   /* The next three bits are for SunOS shared libraries, and seem to
 432            be undocumented.  */
 433 #ifdef TC_NS32K
 434   unsigned int r_bsr:1;
 435   unsigned int r_disp:2;
 436 #else
 437   unsigned int r_baserel:1;     /* Linkage table relative */
 438   unsigned int r_jmptable:1;    /* pc-relative to jump table */
 439   unsigned int r_relative:1;    /* "relative relocation" */
 440 #endif /* TC_NS32K */
 441   /* unused */
 442   unsigned int r_pad:1;         /* Padding -- set to zero */
 443 };
 444
 445 #endif /* CUSTOM_RELOC_FORMAT */
 446
 447 #endif /* __A_OUT_GNU_H__ */
 448
 449 /* end of aout_gnu.h */