gas/a.out.gnu.h

   1 /* This file is a.out.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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #ifndef __A_OUT_GNU_H__
  22 #define __A_OUT_GNU_H__
  23
  24 #include "aout/reloc.h"
  25
  26 #define __GNU_EXEC_MACROS__
  27
  28 #ifndef __STRUCT_EXEC_OVERRIDE__
  29
  30 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
  31    "struct exec".  Don't assume that on this machine, the "struct exec"
  32    will lay out the same sizes or alignments.  */
  33
  34 struct exec_bytes {
  35         unsigned char a_info[4];
  36         unsigned char a_text[4];
  37         unsigned char a_data[4];
  38         unsigned char a_bss[4];
  39         unsigned char a_syms[4];
  40         unsigned char a_entry[4];
  41         unsigned char a_trsize[4];
  42         unsigned char a_drsize[4];
  43 };
  44
  45 /* How big the "struct exec" is on disk */
  46 #define EXEC_BYTES_SIZE (8 * 4)
  47
  48 /* This is the layout in memory of a "struct exec" while we process it.  */
  49
  50 struct exec
  51 {
  52         unsigned long a_info;           /* Use macros N_MAGIC, etc for access */
  53         unsigned a_text;                /* length of text, in bytes */
  54         unsigned a_data;                /* length of data, in bytes */
  55         unsigned a_bss;         /* length of uninitialized data area for file, in bytes */
  56         unsigned a_syms;                /* length of symbol table data in file, in bytes */
  57         unsigned a_entry;               /* start address */
  58         unsigned a_trsize;              /* length of relocation info for text, in bytes */
  59         unsigned a_drsize;              /* length of relocation info for data, in bytes */
  60 };
  61
  62 #endif /* __STRUCT_EXEC_OVERRIDE__ */
  63
  64 /* these go in the N_MACHTYPE field */
  65 /* These symbols could be defined by code from Suns...punt 'em */
  66 #undef M_UNKNOWN
  67 #undef M_68010
  68 #undef M_68020
  69 #undef M_SPARC
  70 enum machine_type {
  71         M_UNKNOWN = 0,
  72         M_68010 = 1,
  73         M_68020 = 2,
  74         M_SPARC = 3,
  75         /* skip a bunch so we don't run into any of sun's numbers */
  76         M_386 = 100,
  77         M_29K = 101,
  78         M_RS6000 = 102, /* IBM RS/6000 */
  79         /* HP/BSD formats */
  80         M_HP200 = 200,  /* hp200 (68010) BSD binary */
  81         M_HP300 = 300,  /* hp300 (68020+68881) BSD binary */
  82         M_HPUX23 = 0x020C,      /* hp200/300 HPUX binary */
  83 };
  84
  85 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
  86 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
  87 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
  88 #define N_SET_INFO(exec, magic, type, flags) \
  89     ((exec).a_info = ((magic) & 0xffff) \
  90      | (((int)(type) & 0xff) << 16) \
  91      | (((flags) & 0xff) << 24))
  92 #define N_SET_MAGIC(exec, magic) \
  93     ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
  94
  95 #define N_SET_MACHTYPE(exec, machtype) \
  96     ((exec).a_info = \
  97      ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
  98
  99 #define N_SET_FLAGS(exec, flags) \
 100     ((exec).a_info = \
 101      ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 102
 103 /* Code indicating object file or impure executable.  */
 104 #define OMAGIC 0407
 105 /* Code indicating pure executable.  */
 106 #define NMAGIC 0410
 107 /* Code indicating demand-paged executable.  */
 108 #define ZMAGIC 0413
 109
 110 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
 111    (almost always "unlinked .o's" these days), should be zero.
 112    For linked files, should reflect reality if we know it.  */
 113
 114 #ifndef N_TXTADDR
 115 #define N_TXTADDR(x)    (N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
 116 #endif
 117
 118 #ifndef N_BADMAG
 119 #define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
 120                            && N_MAGIC(x) != NMAGIC              \
 121                            && N_MAGIC(x) != ZMAGIC)
 122 #endif
 123
 124 /* By default, segment size is constant.  But on some machines, it can
 125    be a function of the a.out header (e.g. machine type).  */
 126 #ifndef N_SEGSIZE
 127 #define N_SEGSIZE(x)    SEGMENT_SIZE
 128 #endif
 129
 130     /* This complexity is for encapsulated COFF support */
 131 #ifndef _N_HDROFF
 132 #define _N_HDROFF(x)    (N_SEGSIZE(x) - sizeof (struct exec))
 133 #endif
 134
 135 #ifndef N_TXTOFF
 136 #define N_TXTOFF(x)     (N_MAGIC(x) == ZMAGIC ? \
 137                          _N_HDROFF((x)) + sizeof (struct exec) :        \
 138                          sizeof (struct exec))
 139 #endif
 140
 141
 142 #ifndef N_DATOFF
 143 #define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text )
 144 #endif
 145
 146 #ifndef N_TRELOFF
 147 #define N_TRELOFF(x)    ( N_DATOFF(x) + (x).a_data )
 148 #endif
 149
 150 #ifndef N_DRELOFF
 151 #define N_DRELOFF(x)    ( N_TRELOFF(x) + (x).a_trsize )
 152 #endif
 153
 154 #ifndef N_SYMOFF
 155 #define N_SYMOFF(x)     ( N_DRELOFF(x) + (x).a_drsize )
 156 #endif
 157
 158 #ifndef N_STROFF
 159 #define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
 160 #endif
 161
 162 /* Address of text segment in memory after it is loaded.  */
 163 #ifndef N_TXTADDR
 164 #define N_TXTADDR(x)    0
 165 #endif
 166
 167 #ifndef N_DATADDR
 168 #define N_DATADDR(x) \
 169     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
 170      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x).a_text-1) & ~(N_SEGSIZE(x)-1))))
 171 #endif
 172
 173 /* Address of bss segment in memory after it is loaded.  */
 174 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
 175 \f
 176 struct nlist {
 177         union {
 178                 char *n_name;
 179                 struct nlist *n_next;
 180                 long n_strx;
 181         } n_un;
 182         unsigned char n_type;
 183         char n_other;
 184         short n_desc;
 185         unsigned long n_value;
 186 };
 187
 188 #define N_UNDF 0
 189 #define N_ABS 2
 190 #define N_TEXT 4
 191 #define N_DATA 6
 192 #define N_BSS 8
 193 #define N_COMM  0x12            /* common (visible in shared lib commons) */
 194 #define N_FN 0x1F               /* File name of a .o file */
 195
 196 /* Note: N_EXT can only usefully be OR-ed with N_UNDF, N_ABS, N_TEXT,
 197    N_DATA, or N_BSS.  When the low-order bit of other types is set,
 198    (e.g. N_WARNING versus N_FN), they are two different types.  */
 199 #define N_EXT 1
 200 #define N_TYPE 036
 201 #define N_STAB 0340
 202
 203 /* The following type indicates the definition of a symbol as being
 204    an indirect reference to another symbol.  The other symbol
 205    appears as an undefined reference, immediately following this symbol.
 206
 207    Indirection is asymmetrical.  The other symbol's value will be used
 208    to satisfy requests for the indirect symbol, but not vice versa.
 209    If the other symbol does not have a definition, libraries will
 210    be searched to find a definition.  */
 211
 212 #define N_INDR 0xa
 213
 214 /* The following symbols refer to set elements.
 215    All the N_SET[ATDB] symbols with the same name form one set.
 216    Space is allocated for the set in the text section, and each set
 217    element's value is stored into one word of the space.
 218    The first word of the space is the length of the set (number of elements).
 219
 220    The address of the set is made into an N_SETV symbol
 221    whose name is the same as the name of the set.
 222    This symbol acts like a N_DATA global symbol
 223    in that it can satisfy undefined external references.  */
 224
 225 /* These appear as input to LD, in a .o file.  */
 226 #define N_SETA  0x14            /* Absolute set element symbol */
 227 #define N_SETT  0x16            /* Text set element symbol */
 228 #define N_SETD  0x18            /* Data set element symbol */
 229 #define N_SETB  0x1A            /* Bss set element symbol */
 230
 231 /* This is output from LD.  */
 232 #define N_SETV  0x1C            /* Pointer to set vector in data area.  */
 233
 234 /* Warning symbol. The text gives a warning message, the next symbol
 235    in the table will be undefined. When the symbol is referenced, the
 236    message is printed.  */
 237
 238 #define N_WARNING 0x1e
 239 \f
 240 /* This structure describes a single relocation to be performed.
 241    The text-relocation section of the file is a vector of these structures,
 242    all of which apply to the text section.
 243    Likewise, the data-relocation section applies to the data section.  */
 244
 245 /* The following enum and struct were borrowed from SunOS's
 246    /usr/include/sun4/a.out.h  and extended to handle
 247    other machines.  It is currently used on SPARC and AMD 29000.
 248
 249    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
 250    how we might process it on a native host.  */
 251
 252 struct reloc_ext_bytes {
 253         unsigned char   r_address[4];
 254         unsigned char r_index[3];
 255         unsigned char r_bits[1];
 256         unsigned char r_addend[4];
 257 };
 258
 259 #define RELOC_EXT_BITS_EXTERN_BIG       0x80
 260 #define RELOC_EXT_BITS_EXTERN_LITTLE    0x01
 261
 262 #define RELOC_EXT_BITS_TYPE_BIG         0x1F
 263 #define RELOC_EXT_BITS_TYPE_SH_BIG      0
 264 #define RELOC_EXT_BITS_TYPE_LITTLE      0xF8
 265 #define RELOC_EXT_BITS_TYPE_SH_LITTLE   3
 266
 267 #define RELOC_EXT_SIZE  12              /* Bytes per relocation entry */
 268
 269 struct reloc_info_extended
 270 {
 271         unsigned long r_address;
 272         unsigned int  r_index:24;
 273 # define        r_symbolnum  r_index
 274         unsigned        r_extern:1;
 275         unsigned        :2;
 276         /*  RS/6000 compiler does not support enum bitfield
 277             enum reloc_type r_type:5; */
 278         enum reloc_type r_type;
 279         long int        r_addend;
 280 };
 281
 282 /* The standard, old-fashioned, Berkeley compatible relocation struct */
 283
 284 struct reloc_std_bytes {
 285         unsigned char   r_address[4];
 286         unsigned char r_index[3];
 287         unsigned char r_bits[1];
 288 };
 289
 290 #define RELOC_STD_BITS_PCREL_BIG        0x80
 291 #define RELOC_STD_BITS_PCREL_LITTLE     0x01
 292
 293 #define RELOC_STD_BITS_LENGTH_BIG       0x60
 294 #define RELOC_STD_BITS_LENGTH_SH_BIG    5       /* To shift to units place */
 295 #define RELOC_STD_BITS_LENGTH_LITTLE    0x06
 296 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
 297
 298 #define RELOC_STD_BITS_EXTERN_BIG       0x10
 299 #define RELOC_STD_BITS_EXTERN_LITTLE    0x08
 300
 301 #define RELOC_STD_BITS_BASEREL_BIG      0x08
 302 #define RELOC_STD_BITS_BASEREL_LITTLE   0x08
 303
 304 #define RELOC_STD_BITS_JMPTABLE_BIG     0x04
 305 #define RELOC_STD_BITS_JMPTABLE_LITTLE  0x04
 306
 307 #define RELOC_STD_BITS_RELATIVE_BIG     0x02
 308 #define RELOC_STD_BITS_RELATIVE_LITTLE  0x02
 309
 310 #define RELOC_STD_SIZE  8               /* Bytes per relocation entry */
 311
 312 #ifndef CUSTOM_RELOC_FORMAT
 313 struct relocation_info
 314 {
 315         /* Address (within segment) to be relocated.  */
 316         int r_address;
 317         /* The meaning of r_symbolnum depends on r_extern.  */
 318         unsigned int r_symbolnum:24;
 319         /* Nonzero means value is a pc-relative offset
 320            and it should be relocated for changes in its own address
 321            as well as for changes in the symbol or section specified.  */
 322         unsigned int r_pcrel:1;
 323         /* Length (as exponent of 2) of the field to be relocated.
 324            Thus, a value of 2 indicates 1<<2 bytes.  */
 325         unsigned int r_length:2;
 326         /* 1 => relocate with value of symbol.
 327            r_symbolnum is the index of the symbol
 328            in file's the symbol table.
 329            0 => relocate with the address of a segment.
 330            r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
 331            (the N_EXT bit may be set also, but signifies nothing).  */
 332         unsigned int r_extern:1;
 333         /* The next three bits are for SunOS shared libraries, and seem to
 334            be undocumented.  */
 335         unsigned int r_baserel:1;       /* Linkage table relative */
 336         unsigned int r_jmptable:1;      /* pc-relative to jump table */
 337
 338 #ifdef TC_NS32K
 339 #define r_bsr   r_baserel
 340 #define r_disp  r_jmptable
 341 #endif /* TC_NS32K */
 342
 343         unsigned int r_relative:1;      /* "relative relocation" */
 344         /* unused */
 345         unsigned int r_pad:1;           /* Padding -- set to zero */
 346 };
 347 #endif /* CUSTOM_RELOC_FORMAT */
 348
 349 #endif /* __A_OUT_GNU_H__ */
 350
 351 /* end of a.out.gnu.h */