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    2005, 2007 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 3, 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,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #ifndef __A_OUT_GNU_H__
  24 #define __A_OUT_GNU_H__
  25
  26 /* There are two main flavours of a.out, one which uses the standard
  27    relocations, and one which uses extended relocations.
  28
  29    Today, the extended reloc uses are
  30    TC_SPARC
  31
  32    each must define the enum reloc_type
  33
  34 */
  35
  36 #define USE_EXTENDED_RELOC defined(TC_SPARC)
  37
  38 #if defined(TC_SPARC)
  39 enum reloc_type
  40   {
  41     RELOC_8, RELOC_16, RELOC_32,/* simple relocations */
  42     RELOC_DISP8, RELOC_DISP16, RELOC_DISP32,    /* pc-rel displacement */
  43     RELOC_WDISP30, RELOC_WDISP22,
  44     RELOC_HI22, RELOC_22,
  45     RELOC_13, RELOC_LO10,
  46     RELOC_SFA_BASE, RELOC_SFA_OFF13,
  47     RELOC_BASE10, RELOC_BASE13, RELOC_BASE22,   /* P.I.C. (base-relative) */
  48     RELOC_PC10, RELOC_PC22,     /* for some sort of pc-rel P.I.C. (?) */
  49     RELOC_JMP_TBL,              /* P.I.C. jump table */
  50     RELOC_SEGOFF16,             /* reputedly for shared libraries somehow */
  51     RELOC_GLOB_DAT, RELOC_JMP_SLOT, RELOC_RELATIVE,
  52     RELOC_10, RELOC_11,
  53     RELOC_WDISP2_14,
  54     RELOC_WDISP19,
  55     RELOC_HHI22,
  56     RELOC_HLO10,
  57
  58     /* 29K relocation types */
  59     RELOC_JUMPTARG, RELOC_CONST, RELOC_CONSTH,
  60
  61     RELOC_WDISP14, RELOC_WDISP21,
  62
  63     NO_RELOC
  64   };
  65
  66 #endif /* TC_SPARC */
  67
  68 #define __GNU_EXEC_MACROS__
  69
  70 #ifndef __STRUCT_EXEC_OVERRIDE__
  71
  72 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
  73    "struct exec".  Don't assume that on this machine, the "struct exec"
  74    will lay out the same sizes or alignments.  */
  75
  76 struct exec_bytes
  77   {
  78     unsigned char a_info[4];
  79     unsigned char a_text[4];
  80     unsigned char a_data[4];
  81     unsigned char a_bss[4];
  82     unsigned char a_syms[4];
  83     unsigned char a_entry[4];
  84     unsigned char a_trsize[4];
  85     unsigned char a_drsize[4];
  86   };
  87
  88 /* How big the "struct exec" is on disk */
  89 #define EXEC_BYTES_SIZE (8 * 4)
  90
  91 /* This is the layout in memory of a "struct exec" while we process it.  */
  92
  93 struct exec
  94 {
  95   unsigned long a_info;         /* Use macros N_MAGIC, etc for access */
  96   unsigned a_text;              /* length of text, in bytes */
  97   unsigned a_data;              /* length of data, in bytes */
  98   unsigned a_bss;               /* length of uninitialized data area for file, in bytes */
  99   unsigned a_syms;              /* length of symbol table data in file, in bytes */
 100   unsigned a_entry;             /* start address */
 101   unsigned a_trsize;            /* length of relocation info for text, in bytes */
 102   unsigned a_drsize;            /* length of relocation info for data, in bytes */
 103 };
 104
 105 #endif /* __STRUCT_EXEC_OVERRIDE__ */
 106
 107 /* these go in the N_MACHTYPE field */
 108 /* These symbols could be defined by code from Suns...punt 'em */
 109 #undef M_UNKNOWN
 110 #undef M_68010
 111 #undef M_68020
 112 #undef M_SPARC
 113 enum machine_type
 114   {
 115     M_UNKNOWN = 0,
 116     M_68010 = 1,
 117     M_68020 = 2,
 118     M_SPARC = 3,
 119     /* skip a bunch so we don't run into any of sun's numbers */
 120     M_386 = 100,
 121     M_29K = 101,
 122     M_RS6000 = 102,             /* IBM RS/6000 */
 123     M_VAX4K_NETBSD = 150,
 124     /* HP/BSD formats */
 125     M_HP200 = 200,              /* hp200 (68010) BSD binary */
 126     M_HP300 = 300,              /* hp300 (68020+68881) BSD binary */
 127     M_HPUX23 = 0x020C           /* hp200/300 HPUX binary */
 128   };
 129
 130 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
 131 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 132 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 133 #define N_SET_INFO(exec, magic, type, flags) \
 134     ((exec).a_info = ((magic) & 0xffff) \
 135      | (((int)(type) & 0xff) << 16) \
 136      | (((flags) & 0xff) << 24))
 137 #define N_SET_MAGIC(exec, magic) \
 138     ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 139
 140 #define N_SET_MACHTYPE(exec, machtype) \
 141     ((exec).a_info = \
 142      ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 143
 144 #define N_SET_FLAGS(exec, flags) \
 145     ((exec).a_info = \
 146      ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 147
 148 /* Code indicating object file or impure executable.  */
 149 #ifndef OMAGIC
 150 #define OMAGIC 0407
 151 #endif
 152 /* Code indicating pure executable.  */
 153 #define NMAGIC 0410
 154 /* Code indicating demand-paged executable.  */
 155 #define ZMAGIC 0413
 156
 157 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
 158    (almost always "unlinked .o's" these days), should be zero.
 159    For linked files, should reflect reality if we know it.  */
 160
 161 #ifndef N_TXTADDR
 162 #define N_TXTADDR(x)    (N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
 163 #endif
 164
 165 #ifndef N_BADMAG
 166 #define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
 167                            && N_MAGIC(x) != NMAGIC              \
 168                            && N_MAGIC(x) != ZMAGIC)
 169 #endif
 170
 171 /* By default, segment size is constant.  But on some machines, it can
 172    be a function of the a.out header (e.g. machine type).  */
 173 #ifndef N_SEGSIZE
 174 #define N_SEGSIZE(x)    SEGMENT_SIZE
 175 #endif
 176
 177 /* This complexity is for encapsulated COFF support */
 178 #ifndef _N_HDROFF
 179 #define _N_HDROFF(x)    (N_SEGSIZE(x) - sizeof (struct exec))
 180 #endif
 181
 182 #ifndef N_TXTOFF
 183 #define N_TXTOFF(x)     (N_MAGIC(x) == ZMAGIC ? \
 184                          _N_HDROFF((x)) + sizeof (struct exec) :        \
 185                          sizeof (struct exec))
 186 #endif
 187
 188 #ifndef N_DATOFF
 189 #define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text )
 190 #endif
 191
 192 #ifndef N_TRELOFF
 193 #define N_TRELOFF(x)    ( N_DATOFF(x) + (x).a_data )
 194 #endif
 195
 196 #ifndef N_DRELOFF
 197 #define N_DRELOFF(x)    ( N_TRELOFF(x) + (x).a_trsize )
 198 #endif
 199
 200 #ifndef N_SYMOFF
 201 #define N_SYMOFF(x)     ( N_DRELOFF(x) + (x).a_drsize )
 202 #endif
 203
 204 #ifndef N_STROFF
 205 #define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
 206 #endif
 207
 208 /* Address of text segment in memory after it is loaded.  */
 209 #ifndef N_TXTADDR
 210 #define N_TXTADDR(x)    0
 211 #endif
 212
 213 #ifndef N_DATADDR
 214 #define N_DATADDR(x) \
 215     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
 216      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x).a_text-1) & ~(N_SEGSIZE(x)-1))))
 217 #endif
 218
 219 /* Address of bss segment in memory after it is loaded.  */
 220 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
 221 \f
 222 struct nlist
 223   {
 224     union
 225       {
 226         char *n_name;
 227         struct nlist *n_next;
 228         long n_strx;
 229       }
 230     n_un;
 231     unsigned char n_type;
 232     char n_other;
 233     short n_desc;
 234     unsigned long n_value;
 235   };
 236
 237 #define N_UNDF 0
 238 #define N_ABS 2
 239 #define N_TEXT 4
 240 #define N_DATA 6
 241 #define N_BSS 8
 242 #define N_COMM  0x12            /* common (visible in shared lib commons) */
 243 #define N_FN 0x1F               /* File name of a .o file */
 244
 245 /* Note: N_EXT can only usefully be OR-ed with N_UNDF, N_ABS, N_TEXT,
 246    N_DATA, or N_BSS.  When the low-order bit of other types is set,
 247    (e.g. N_WARNING versus N_FN), they are two different types.  */
 248 #define N_EXT 1
 249 #define N_TYPE 036
 250 #define N_STAB 0340
 251
 252 /* The following type indicates the definition of a symbol as being
 253    an indirect reference to another symbol.  The other symbol
 254    appears as an undefined reference, immediately following this symbol.
 255
 256    Indirection is asymmetrical.  The other symbol's value will be used
 257    to satisfy requests for the indirect symbol, but not vice versa.
 258    If the other symbol does not have a definition, libraries will
 259    be searched to find a definition.  */
 260
 261 #define N_INDR 0xa
 262
 263 /* The following symbols refer to set elements.
 264    All the N_SET[ATDB] symbols with the same name form one set.
 265    Space is allocated for the set in the text section, and each set
 266    element's value is stored into one word of the space.
 267    The first word of the space is the length of the set (number of elements).
 268
 269    The address of the set is made into an N_SETV symbol
 270    whose name is the same as the name of the set.
 271    This symbol acts like a N_DATA global symbol
 272    in that it can satisfy undefined external references.  */
 273
 274 /* These appear as input to LD, in a .o file.  */
 275 #define N_SETA  0x14            /* Absolute set element symbol */
 276 #define N_SETT  0x16            /* Text set element symbol */
 277 #define N_SETD  0x18            /* Data set element symbol */
 278 #define N_SETB  0x1A            /* Bss set element symbol */
 279
 280 /* This is output from LD.  */
 281 #define N_SETV  0x1C            /* Pointer to set vector in data area.  */
 282
 283 /* Warning symbol. The text gives a warning message, the next symbol
 284    in the table will be undefined. When the symbol is referenced, the
 285    message is printed.  */
 286
 287 #define N_WARNING 0x1e
 288
 289 /* Weak symbols.  These are a GNU extension to the a.out format.  The
 290    semantics are those of ELF weak symbols.  Weak symbols are always
 291    externally visible.  The N_WEAK? values are squeezed into the
 292    available slots.  The value of a N_WEAKU symbol is 0.  The values
 293    of the other types are the definitions.  */
 294 #define N_WEAKU 0x0d            /* Weak undefined symbol.  */
 295 #define N_WEAKA 0x0e            /* Weak absolute symbol.  */
 296 #define N_WEAKT 0x0f            /* Weak text symbol.  */
 297 #define N_WEAKD 0x10            /* Weak data symbol.  */
 298 #define N_WEAKB 0x11            /* Weak bss symbol.  */
 299 \f
 300 /* This structure describes a single relocation to be performed.
 301    The text-relocation section of the file is a vector of these structures,
 302    all of which apply to the text section.
 303    Likewise, the data-relocation section applies to the data section.  */
 304
 305 /* The following enum and struct were borrowed from SunOS's
 306    /usr/include/sun4/a.out.h  and extended to handle
 307    other machines.  It is currently used on SPARC and AMD 29000.
 308
 309    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
 310    how we might process it on a native host.  */
 311 #if USE_EXTENDED_RELOC
 312
 313 struct reloc_ext_bytes
 314   {
 315     unsigned char r_address[4];
 316     unsigned char r_index[3];
 317     unsigned char r_bits[1];
 318     unsigned char r_addend[4];
 319   };
 320
 321 #define RELOC_EXT_BITS_EXTERN_BIG       0x80
 322 #define RELOC_EXT_BITS_EXTERN_LITTLE    0x01
 323
 324 #define RELOC_EXT_BITS_TYPE_BIG         0x1F
 325 #define RELOC_EXT_BITS_TYPE_SH_BIG      0
 326 #define RELOC_EXT_BITS_TYPE_LITTLE      0xF8
 327 #define RELOC_EXT_BITS_TYPE_SH_LITTLE   3
 328
 329 #define RELOC_EXT_SIZE  12      /* Bytes per relocation entry */
 330
 331 struct reloc_info_extended
 332 {
 333   unsigned long r_address;
 334   unsigned int r_index:24;
 335 # define        r_symbolnum  r_index
 336   unsigned r_extern:1;
 337   unsigned:2;
 338   /*  RS/6000 compiler does not support enum bitfield
 339             enum reloc_type r_type:5; */
 340   enum reloc_type r_type;
 341   long int r_addend;
 342 };
 343
 344 #else
 345
 346 /* The standard, old-fashioned, Berkeley compatible relocation struct */
 347
 348 #ifdef TC_I860
 349 /* NOTE: three bits max, see struct reloc_info_i860.r_type */
 350 enum i860_reloc_type
 351   {
 352     NO_RELOC = 0, BRADDR, LOW0, LOW1, LOW2, LOW3, LOW4, SPLIT0, SPLIT1, SPLIT2, RELOC_32,
 353   };
 354
 355 typedef enum i860_reloc_type reloc_type;
 356
 357 /* NOTE: two bits max, see reloc_info_i860.r_type */
 358 enum highlow_type
 359   {
 360     NO_SPEC = 0, PAIR, HIGH, HIGHADJ,
 361   };
 362
 363 struct reloc_info_i860
 364 {
 365   unsigned long r_address;
 366   /*
 367          * Using bit fields here is a bad idea because the order is not portable. :-(
 368          */
 369   unsigned int r_symbolnum:24;
 370   unsigned int r_pcrel:1;
 371   unsigned int r_extern:1;
 372   /* combining the two field simplifies the argument passing in "new_fix()" */
 373   /* and is compatible with the existing Sparc #ifdef's */
 374   /* r_type:  highlow_type - bits 5,4; reloc_type - bits 3-0 */
 375   unsigned int r_type:6;
 376   long r_addend;
 377 };
 378
 379 #endif /* TC_I860 */
 380
 381 struct reloc_std_bytes
 382   {
 383     unsigned char r_address[4];
 384     unsigned char r_index[3];
 385     unsigned char r_bits[1];
 386   };
 387
 388 #define RELOC_STD_BITS_PCREL_BIG        0x80
 389 #define RELOC_STD_BITS_PCREL_LITTLE     0x01
 390
 391 #define RELOC_STD_BITS_LENGTH_BIG       0x60
 392 #define RELOC_STD_BITS_LENGTH_SH_BIG    5       /* To shift to units place */
 393 #define RELOC_STD_BITS_LENGTH_LITTLE    0x06
 394 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
 395
 396 #define RELOC_STD_BITS_EXTERN_BIG       0x10
 397 #define RELOC_STD_BITS_EXTERN_LITTLE    0x08
 398
 399 #define RELOC_STD_BITS_BASEREL_BIG      0x08
 400 #define RELOC_STD_BITS_BASEREL_LITTLE   0x08
 401
 402 #define RELOC_STD_BITS_JMPTABLE_BIG     0x04
 403 #define RELOC_STD_BITS_JMPTABLE_LITTLE  0x04
 404
 405 #define RELOC_STD_BITS_RELATIVE_BIG     0x02
 406 #define RELOC_STD_BITS_RELATIVE_LITTLE  0x02
 407
 408 #define RELOC_STD_SIZE  8       /* Bytes per relocation entry */
 409
 410 #endif /* USE_EXTENDED_RELOC */
 411
 412 #ifndef CUSTOM_RELOC_FORMAT
 413 struct relocation_info
 414 {
 415   /* Address (within segment) to be relocated.  */
 416   int r_address;
 417   /* The meaning of r_symbolnum depends on r_extern.  */
 418   unsigned int r_symbolnum:24;
 419   /* Nonzero means value is a pc-relative offset
 420            and it should be relocated for changes in its own address
 421            as well as for changes in the symbol or section specified.  */
 422   unsigned int r_pcrel:1;
 423   /* Length (as exponent of 2) of the field to be relocated.
 424            Thus, a value of 2 indicates 1<<2 bytes.  */
 425   unsigned int r_length:2;
 426   /* 1 => relocate with value of symbol.
 427            r_symbolnum is the index of the symbol
 428            in file's the symbol table.
 429            0 => relocate with the address of a segment.
 430            r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
 431            (the N_EXT bit may be set also, but signifies nothing).  */
 432   unsigned int r_extern:1;
 433   /* The next three bits are for SunOS shared libraries, and seem to
 434            be undocumented.  */
 435 #ifdef TC_NS32K
 436   unsigned int r_bsr:1;
 437   unsigned int r_disp:2;
 438 #else
 439   unsigned int r_baserel:1;     /* Linkage table relative */
 440   unsigned int r_jmptable:1;    /* pc-relative to jump table */
 441   unsigned int r_relative:1;    /* "relative relocation" */
 442 #endif /* TC_NS32K */
 443   /* unused */
 444   unsigned int r_pad:1;         /* Padding -- set to zero */
 445 };
 446
 447 #endif /* CUSTOM_RELOC_FORMAT */
 448
 449 #endif /* __A_OUT_GNU_H__ */
 450
 451 /* end of aout_gnu.h */