gas/config/aout_gnu.h

   1 /* This file is aout_gnu.h
   2
   3    Copyright (C) 1987-1992 Free Software Foundation, Inc.
   4
   5    This file is part of GAS, the GNU Assembler.
   6
   7    GAS 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, or (at your option)
  10    any later version.
  11
  12    GAS 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 GAS; see the file COPYING.  If not, write to
  19    the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 #ifndef __A_OUT_GNU_H__
  22 #define __A_OUT_GNU_H__
  23
  24 /* There are two main flavours of a.out, one which uses the standard
  25    relocations, and one which uses extended relocations.
  26
  27    Today, the extended reloc uses are
  28    TC_SPARC, TC_A29K
  29
  30    each must define the enum reloc_type
  31
  32 */
  33
  34 #define USE_EXTENDED_RELOC (defined(TC_SPARC) || defined(TC_A29K))
  35
  36 #if defined(TC_SPARC) || defined(TC_A29K)
  37 enum reloc_type
  38   {
  39     RELOC_8, RELOC_16, RELOC_32,/* simple relocations */
  40     RELOC_DISP8, RELOC_DISP16, RELOC_DISP32,    /* pc-rel displacement */
  41     RELOC_WDISP30, RELOC_WDISP22,
  42     RELOC_HI22, RELOC_22,
  43     RELOC_13, RELOC_LO10,
  44     RELOC_SFA_BASE, RELOC_SFA_OFF13,
  45     RELOC_BASE10, RELOC_BASE13, RELOC_BASE22,   /* P.I.C. (base-relative) */
  46     RELOC_PC10, RELOC_PC22,     /* for some sort of pc-rel P.I.C. (?) */
  47     RELOC_JMP_TBL,              /* P.I.C. jump table */
  48     RELOC_SEGOFF16,             /* reputedly for shared libraries somehow */
  49     RELOC_GLOB_DAT, RELOC_JMP_SLOT, RELOC_RELATIVE,
  50     RELOC_10, RELOC_11,
  51     RELOC_WDISP2_14,
  52     RELOC_WDISP19,
  53     RELOC_HHI22,
  54     RELOC_HLO10,
  55
  56     /* 29K relocation types */
  57     RELOC_JUMPTARG, RELOC_CONST, RELOC_CONSTH,
  58
  59     RELOC_WDISP14, RELOC_WDISP21,
  60
  61     NO_RELOC
  62   };
  63
  64 #endif /* TC_SPARC or TC_A29K */
  65
  66 #define __GNU_EXEC_MACROS__
  67
  68 #ifndef __STRUCT_EXEC_OVERRIDE__
  69
  70 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
  71    "struct exec".  Don't assume that on this machine, the "struct exec"
  72    will lay out the same sizes or alignments.  */
  73
  74 struct exec_bytes
  75   {
  76     unsigned char a_info[4];
  77     unsigned char a_text[4];
  78     unsigned char a_data[4];
  79     unsigned char a_bss[4];
  80     unsigned char a_syms[4];
  81     unsigned char a_entry[4];
  82     unsigned char a_trsize[4];
  83     unsigned char a_drsize[4];
  84   };
  85
  86 /* How big the "struct exec" is on disk */
  87 #define EXEC_BYTES_SIZE (8 * 4)
  88
  89 /* This is the layout in memory of a "struct exec" while we process it.  */
  90
  91 struct exec
  92 {
  93   unsigned long a_info;         /* Use macros N_MAGIC, etc for access */
  94   unsigned a_text;              /* length of text, in bytes */
  95   unsigned a_data;              /* length of data, in bytes */
  96   unsigned a_bss;               /* length of uninitialized data area for file, in bytes */
  97   unsigned a_syms;              /* length of symbol table data in file, in bytes */
  98   unsigned a_entry;             /* start address */
  99   unsigned a_trsize;            /* length of relocation info for text, in bytes */
 100   unsigned a_drsize;            /* length of relocation info for data, in bytes */
 101 };
 102
 103 #endif /* __STRUCT_EXEC_OVERRIDE__ */
 104
 105 /* these go in the N_MACHTYPE field */
 106 /* These symbols could be defined by code from Suns...punt 'em */
 107 #undef M_UNKNOWN
 108 #undef M_68010
 109 #undef M_68020
 110 #undef M_SPARC
 111 enum machine_type
 112   {
 113     M_UNKNOWN = 0,
 114     M_68010 = 1,
 115     M_68020 = 2,
 116     M_SPARC = 3,
 117     /* skip a bunch so we don't run into any of sun's numbers */
 118     M_386 = 100,
 119     M_29K = 101,
 120     M_RS6000 = 102,             /* IBM RS/6000 */
 121     /* HP/BSD formats */
 122     M_HP200 = 200,              /* hp200 (68010) BSD binary */
 123     M_HP300 = 300,              /* hp300 (68020+68881) BSD binary */
 124     M_HPUX23 = 0x020C           /* hp200/300 HPUX binary */
 125   };
 126
 127 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
 128 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 129 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 130 #define N_SET_INFO(exec, magic, type, flags) \
 131     ((exec).a_info = ((magic) & 0xffff) \
 132      | (((int)(type) & 0xff) << 16) \
 133      | (((flags) & 0xff) << 24))
 134 #define N_SET_MAGIC(exec, magic) \
 135     ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 136
 137 #define N_SET_MACHTYPE(exec, machtype) \
 138     ((exec).a_info = \
 139      ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 140
 141 #define N_SET_FLAGS(exec, flags) \
 142     ((exec).a_info = \
 143      ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 144
 145 /* Code indicating object file or impure executable.  */
 146 #ifndef OMAGIC
 147 #define OMAGIC 0407
 148 #endif
 149 /* Code indicating pure executable.  */
 150 #define NMAGIC 0410
 151 /* Code indicating demand-paged executable.  */
 152 #define ZMAGIC 0413
 153
 154 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
 155    (almost always "unlinked .o's" these days), should be zero.
 156    For linked files, should reflect reality if we know it.  */
 157
 158 #ifndef N_TXTADDR
 159 #define N_TXTADDR(x)    (N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
 160 #endif
 161
 162 #ifndef N_BADMAG
 163 #define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
 164                            && N_MAGIC(x) != NMAGIC              \
 165                            && N_MAGIC(x) != ZMAGIC)
 166 #endif
 167
 168 /* By default, segment size is constant.  But on some machines, it can
 169    be a function of the a.out header (e.g. machine type).  */
 170 #ifndef N_SEGSIZE
 171 #define N_SEGSIZE(x)    SEGMENT_SIZE
 172 #endif
 173
 174 /* This complexity is for encapsulated COFF support */
 175 #ifndef _N_HDROFF
 176 #define _N_HDROFF(x)    (N_SEGSIZE(x) - sizeof (struct exec))
 177 #endif
 178
 179 #ifndef N_TXTOFF
 180 #define N_TXTOFF(x)     (N_MAGIC(x) == ZMAGIC ? \
 181                          _N_HDROFF((x)) + sizeof (struct exec) :        \
 182                          sizeof (struct exec))
 183 #endif
 184
 185 #ifndef N_DATOFF
 186 #define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text )
 187 #endif
 188
 189 #ifndef N_TRELOFF
 190 #define N_TRELOFF(x)    ( N_DATOFF(x) + (x).a_data )
 191 #endif
 192
 193 #ifndef N_DRELOFF
 194 #define N_DRELOFF(x)    ( N_TRELOFF(x) + (x).a_trsize )
 195 #endif
 196
 197 #ifndef N_SYMOFF
 198 #define N_SYMOFF(x)     ( N_DRELOFF(x) + (x).a_drsize )
 199 #endif
 200
 201 #ifndef N_STROFF
 202 #define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
 203 #endif
 204
 205 /* Address of text segment in memory after it is loaded.  */
 206 #ifndef N_TXTADDR
 207 #define N_TXTADDR(x)    0
 208 #endif
 209
 210 #ifndef N_DATADDR
 211 #define N_DATADDR(x) \
 212     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
 213      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x).a_text-1) & ~(N_SEGSIZE(x)-1))))
 214 #endif
 215
 216 /* Address of bss segment in memory after it is loaded.  */
 217 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
 218 \f
 219 struct nlist
 220   {
 221     union
 222       {
 223         char *n_name;
 224         struct nlist *n_next;
 225         long n_strx;
 226       }
 227     n_un;
 228     unsigned char n_type;
 229     char n_other;
 230     short n_desc;
 231     unsigned long n_value;
 232   };
 233
 234 #define N_UNDF 0
 235 #define N_ABS 2
 236 #define N_TEXT 4
 237 #define N_DATA 6
 238 #define N_BSS 8
 239 #define N_COMM  0x12            /* common (visible in shared lib commons) */
 240 #define N_FN 0x1F               /* File name of a .o file */
 241
 242 /* Note: N_EXT can only usefully be OR-ed with N_UNDF, N_ABS, N_TEXT,
 243    N_DATA, or N_BSS.  When the low-order bit of other types is set,
 244    (e.g. N_WARNING versus N_FN), they are two different types.  */
 245 #define N_EXT 1
 246 #define N_TYPE 036
 247 #define N_STAB 0340
 248
 249 /* The following type indicates the definition of a symbol as being
 250    an indirect reference to another symbol.  The other symbol
 251    appears as an undefined reference, immediately following this symbol.
 252
 253    Indirection is asymmetrical.  The other symbol's value will be used
 254    to satisfy requests for the indirect symbol, but not vice versa.
 255    If the other symbol does not have a definition, libraries will
 256    be searched to find a definition.  */
 257
 258 #define N_INDR 0xa
 259
 260 /* The following symbols refer to set elements.
 261    All the N_SET[ATDB] symbols with the same name form one set.
 262    Space is allocated for the set in the text section, and each set
 263    element's value is stored into one word of the space.
 264    The first word of the space is the length of the set (number of elements).
 265
 266    The address of the set is made into an N_SETV symbol
 267    whose name is the same as the name of the set.
 268    This symbol acts like a N_DATA global symbol
 269    in that it can satisfy undefined external references.  */
 270
 271 /* These appear as input to LD, in a .o file.  */
 272 #define N_SETA  0x14            /* Absolute set element symbol */
 273 #define N_SETT  0x16            /* Text set element symbol */
 274 #define N_SETD  0x18            /* Data set element symbol */
 275 #define N_SETB  0x1A            /* Bss set element symbol */
 276
 277 /* This is output from LD.  */
 278 #define N_SETV  0x1C            /* Pointer to set vector in data area.  */
 279
 280 /* Warning symbol. The text gives a warning message, the next symbol
 281    in the table will be undefined. When the symbol is referenced, the
 282    message is printed.  */
 283
 284 #define N_WARNING 0x1e
 285
 286 /* Weak symbols.  These are a GNU extension to the a.out format.  The
 287    semantics are those of ELF weak symbols.  Weak symbols are always
 288    externally visible.  The N_WEAK? values are squeezed into the
 289    available slots.  The value of a N_WEAKU symbol is 0.  The values
 290    of the other types are the definitions.  */
 291 #define N_WEAKU 0x0d            /* Weak undefined symbol.  */
 292 #define N_WEAKA 0x0e            /* Weak absolute symbol.  */
 293 #define N_WEAKT 0x0f            /* Weak text symbol.  */
 294 #define N_WEAKD 0x10            /* Weak data symbol.  */
 295 #define N_WEAKB 0x11            /* Weak bss symbol.  */
 296 \f
 297 /* This structure describes a single relocation to be performed.
 298    The text-relocation section of the file is a vector of these structures,
 299    all of which apply to the text section.
 300    Likewise, the data-relocation section applies to the data section.  */
 301
 302 /* The following enum and struct were borrowed from SunOS's
 303    /usr/include/sun4/a.out.h  and extended to handle
 304    other machines.  It is currently used on SPARC and AMD 29000.
 305
 306    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
 307    how we might process it on a native host.  */
 308 #if USE_EXTENDED_RELOC
 309
 310 struct reloc_ext_bytes
 311   {
 312     unsigned char r_address[4];
 313     unsigned char r_index[3];
 314     unsigned char r_bits[1];
 315     unsigned char r_addend[4];
 316   };
 317
 318 #define RELOC_EXT_BITS_EXTERN_BIG       0x80
 319 #define RELOC_EXT_BITS_EXTERN_LITTLE    0x01
 320
 321 #define RELOC_EXT_BITS_TYPE_BIG         0x1F
 322 #define RELOC_EXT_BITS_TYPE_SH_BIG      0
 323 #define RELOC_EXT_BITS_TYPE_LITTLE      0xF8
 324 #define RELOC_EXT_BITS_TYPE_SH_LITTLE   3
 325
 326 #define RELOC_EXT_SIZE  12      /* Bytes per relocation entry */
 327
 328 struct reloc_info_extended
 329 {
 330   unsigned long r_address;
 331   unsigned int r_index:24;
 332 # define        r_symbolnum  r_index
 333   unsigned r_extern:1;
 334   unsigned:2;
 335   /*  RS/6000 compiler does not support enum bitfield
 336             enum reloc_type r_type:5; */
 337   enum reloc_type r_type;
 338   long int r_addend;
 339 };
 340
 341 #else
 342
 343 /* The standard, old-fashioned, Berkeley compatible relocation struct */
 344
 345 #ifdef TC_I860
 346 /* NOTE: three bits max, see struct reloc_info_i860.r_type */
 347 enum i860_reloc_type
 348   {
 349     NO_RELOC = 0, BRADDR, LOW0, LOW1, LOW2, LOW3, LOW4, SPLIT0, SPLIT1, SPLIT2, RELOC_32,
 350   };
 351
 352 typedef enum i860_reloc_type reloc_type;
 353
 354 /* NOTE: two bits max, see reloc_info_i860.r_type */
 355 enum highlow_type
 356   {
 357     NO_SPEC = 0, PAIR, HIGH, HIGHADJ,
 358   };
 359
 360 struct reloc_info_i860
 361 {
 362   unsigned long r_address;
 363   /*
 364          * Using bit fields here is a bad idea because the order is not portable. :-(
 365          */
 366   unsigned int r_symbolnum:24;
 367   unsigned int r_pcrel:1;
 368   unsigned int r_extern:1;
 369   /* combining the two field simplifies the argument passing in "new_fix()" */
 370   /* and is compatible with the existing Sparc #ifdef's */
 371   /* r_type:  highlow_type - bits 5,4; reloc_type - bits 3-0 */
 372   unsigned int r_type:6;
 373   long r_addend;
 374 };
 375
 376 #endif /* TC_I860 */
 377
 378 struct reloc_std_bytes
 379   {
 380     unsigned char r_address[4];
 381     unsigned char r_index[3];
 382     unsigned char r_bits[1];
 383   };
 384
 385 #define RELOC_STD_BITS_PCREL_BIG        0x80
 386 #define RELOC_STD_BITS_PCREL_LITTLE     0x01
 387
 388 #define RELOC_STD_BITS_LENGTH_BIG       0x60
 389 #define RELOC_STD_BITS_LENGTH_SH_BIG    5       /* To shift to units place */
 390 #define RELOC_STD_BITS_LENGTH_LITTLE    0x06
 391 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
 392
 393 #define RELOC_STD_BITS_EXTERN_BIG       0x10
 394 #define RELOC_STD_BITS_EXTERN_LITTLE    0x08
 395
 396 #define RELOC_STD_BITS_BASEREL_BIG      0x08
 397 #define RELOC_STD_BITS_BASEREL_LITTLE   0x08
 398
 399 #define RELOC_STD_BITS_JMPTABLE_BIG     0x04
 400 #define RELOC_STD_BITS_JMPTABLE_LITTLE  0x04
 401
 402 #define RELOC_STD_BITS_RELATIVE_BIG     0x02
 403 #define RELOC_STD_BITS_RELATIVE_LITTLE  0x02
 404
 405 #define RELOC_STD_SIZE  8       /* Bytes per relocation entry */
 406
 407 #endif /* USE_EXTENDED_RELOC */
 408
 409 #ifndef CUSTOM_RELOC_FORMAT
 410 struct relocation_info
 411 {
 412   /* Address (within segment) to be relocated.  */
 413   int r_address;
 414   /* The meaning of r_symbolnum depends on r_extern.  */
 415   unsigned int r_symbolnum:24;
 416   /* Nonzero means value is a pc-relative offset
 417            and it should be relocated for changes in its own address
 418            as well as for changes in the symbol or section specified.  */
 419   unsigned int r_pcrel:1;
 420   /* Length (as exponent of 2) of the field to be relocated.
 421            Thus, a value of 2 indicates 1<<2 bytes.  */
 422   unsigned int r_length:2;
 423   /* 1 => relocate with value of symbol.
 424            r_symbolnum is the index of the symbol
 425            in file's the symbol table.
 426            0 => relocate with the address of a segment.
 427            r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
 428            (the N_EXT bit may be set also, but signifies nothing).  */
 429   unsigned int r_extern:1;
 430   /* The next three bits are for SunOS shared libraries, and seem to
 431            be undocumented.  */
 432 #ifdef TC_NS32K
 433   unsigned int r_bsr:1;
 434   unsigned int r_disp:2;
 435 #else
 436   unsigned int r_baserel:1;     /* Linkage table relative */
 437   unsigned int r_jmptable:1;    /* pc-relative to jump table */
 438   unsigned int r_relative:1;    /* "relative relocation" */
 439 #endif /* TC_NS32K */
 440   /* unused */
 441   unsigned int r_pad:1;         /* Padding -- set to zero */
 442 };
 443
 444 #endif /* CUSTOM_RELOC_FORMAT */
 445
 446 #endif /* __A_OUT_GNU_H__ */
 447
 448 /* end of aout_gnu.h */