gas/a.out.gnu.h

   1 #ifndef __A_OUT_GNU_H__
   2 #define __A_OUT_GNU_H__
   3
   4 #include "reloc.h"
   5
   6 #define __GNU_EXEC_MACROS__
   7
   8 #ifndef __STRUCT_EXEC_OVERRIDE__
   9
  10 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
  11    "struct exec".  Don't assume that on this machine, the "struct exec"
  12    will lay out the same sizes or alignments.  */
  13
  14 struct exec_bytes {
  15   unsigned char a_info[4];
  16   unsigned char a_text[4];
  17   unsigned char a_data[4];
  18   unsigned char a_bss[4];
  19   unsigned char a_syms[4];
  20   unsigned char a_entry[4];
  21   unsigned char a_trsize[4];
  22   unsigned char a_drsize[4];
  23 };
  24
  25 /* How big the "struct exec" is on disk */
  26 #define EXEC_BYTES_SIZE (8 * 4)
  27
  28 /* This is the layout in memory of a "struct exec" while we process it.  */
  29
  30 struct exec
  31 {
  32   unsigned long a_info;         /* Use macros N_MAGIC, etc for access */
  33   unsigned a_text;              /* length of text, in bytes */
  34   unsigned a_data;              /* length of data, in bytes */
  35   unsigned a_bss;               /* length of uninitialized data area for file, in bytes */
  36   unsigned a_syms;              /* length of symbol table data in file, in bytes */
  37   unsigned a_entry;             /* start address */
  38   unsigned a_trsize;            /* length of relocation info for text, in bytes */
  39   unsigned a_drsize;            /* length of relocation info for data, in bytes */
  40 };
  41
  42 #endif /* __STRUCT_EXEC_OVERRIDE__ */
  43
  44 /* these go in the N_MACHTYPE field */
  45 /* These symbols could be defined by code from Suns...punt 'em */
  46 #undef M_UNKNOWN
  47 #undef M_68010
  48 #undef M_68020
  49 #undef M_SPARC
  50 enum machine_type {
  51   M_UNKNOWN = 0,
  52   M_68010 = 1,
  53   M_68020 = 2,
  54   M_SPARC = 3,
  55   /* skip a bunch so we don't run into any of sun's numbers */
  56   M_386 = 100,
  57   M_29K = 101,
  58   /* HP/BSD formats */
  59   M_HP200 = 200,        /* hp200 (68010) BSD binary */
  60   M_HP300 = 300,        /* hp300 (68020+68881) BSD binary */
  61   M_HPUX23 = 0x020C,    /* hp200/300 HPUX binary */
  62 };
  63
  64 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
  65 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
  66 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
  67 #define N_SET_INFO(exec, magic, type, flags) \
  68         ((exec).a_info = ((magic) & 0xffff) \
  69          | (((int)(type) & 0xff) << 16) \
  70          | (((flags) & 0xff) << 24))
  71 #define N_SET_MAGIC(exec, magic) \
  72         ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
  73
  74 #define N_SET_MACHTYPE(exec, machtype) \
  75         ((exec).a_info = \
  76          ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
  77
  78 #define N_SET_FLAGS(exec, flags) \
  79         ((exec).a_info = \
  80          ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
  81
  82 /* Code indicating object file or impure executable.  */
  83 #define OMAGIC 0407
  84 /* Code indicating pure executable.  */
  85 #define NMAGIC 0410
  86 /* Code indicating demand-paged executable.  */
  87 #define ZMAGIC 0413
  88
  89 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
  90    (almost always "unlinked .o's" these days), should be zero.
  91    For linked files, should reflect reality if we know it.  */
  92
  93 #ifndef N_TXTADDR
  94 #define N_TXTADDR(x)    (N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
  95 #endif
  96
  97 #ifndef N_BADMAG
  98 #define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
  99                         && N_MAGIC(x) != NMAGIC         \
 100                         && N_MAGIC(x) != ZMAGIC)
 101 #endif
 102
 103 /* By default, segment size is constant.  But on some machines, it can
 104    be a function of the a.out header (e.g. machine type).  */
 105 #ifndef N_SEGSIZE
 106 #define N_SEGSIZE(x)    SEGMENT_SIZE
 107 #endif
 108
 109 /* This complexity is for encapsulated COFF support */
 110 #ifndef _N_HDROFF
 111 #define _N_HDROFF(x)    (N_SEGSIZE(x) - sizeof (struct exec))
 112 #endif
 113
 114 #ifndef N_TXTOFF
 115 #define N_TXTOFF(x)     (N_MAGIC(x) == ZMAGIC ? \
 116                                 _N_HDROFF((x)) + sizeof (struct exec) : \
 117                                 sizeof (struct exec))
 118 #endif
 119
 120
 121 #ifndef N_DATOFF
 122 #define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text )
 123 #endif
 124
 125 #ifndef N_TRELOFF
 126 #define N_TRELOFF(x)    ( N_DATOFF(x) + (x).a_data )
 127 #endif
 128
 129 #ifndef N_DRELOFF
 130 #define N_DRELOFF(x)    ( N_TRELOFF(x) + (x).a_trsize )
 131 #endif
 132
 133 #ifndef N_SYMOFF
 134 #define N_SYMOFF(x)     ( N_DRELOFF(x) + (x).a_drsize )
 135 #endif
 136
 137 #ifndef N_STROFF
 138 #define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
 139 #endif
 140
 141 /* Address of text segment in memory after it is loaded.  */
 142 #ifndef N_TXTADDR
 143 #define N_TXTADDR(x)    0
 144 #endif
 145
 146 #ifndef N_DATADDR
 147 #define N_DATADDR(x) \
 148     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
 149      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x).a_text-1) & ~(N_SEGSIZE(x)-1))))
 150 #endif
 151
 152 /* Address of bss segment in memory after it is loaded.  */
 153 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
 154 \f
 155 struct nlist {
 156   union {
 157     char *n_name;
 158     struct nlist *n_next;
 159     long n_strx;
 160   } n_un;
 161   unsigned char n_type;
 162   char n_other;
 163   short n_desc;
 164   unsigned long n_value;
 165 };
 166
 167 #define N_UNDF 0
 168 #define N_ABS 2
 169 #define N_TEXT 4
 170 #define N_DATA 6
 171 #define N_BSS 8
 172 #define N_FN 0xe
 173 #define N_COMM  0x12            /* common (visible in shared lib commons) */
 174
 175 #define N_EXT 1
 176 #define N_TYPE 036
 177 #define N_STAB 0340
 178
 179 /* The following type indicates the definition of a symbol as being
 180    an indirect reference to another symbol.  The other symbol
 181    appears as an undefined reference, immediately following this symbol.
 182
 183    Indirection is asymmetrical.  The other symbol's value will be used
 184    to satisfy requests for the indirect symbol, but not vice versa.
 185    If the other symbol does not have a definition, libraries will
 186    be searched to find a definition.  */
 187
 188 #define N_INDR 0xa
 189
 190 /* The following symbols refer to set elements.
 191    All the N_SET[ATDB] symbols with the same name form one set.
 192    Space is allocated for the set in the text section, and each set
 193    element's value is stored into one word of the space.
 194    The first word of the space is the length of the set (number of elements).
 195
 196    The address of the set is made into an N_SETV symbol
 197    whose name is the same as the name of the set.
 198    This symbol acts like a N_DATA global symbol
 199    in that it can satisfy undefined external references.  */
 200
 201 /* These appear as input to LD, in a .o file.  */
 202 #define N_SETA  0x14            /* Absolute set element symbol */
 203 #define N_SETT  0x16            /* Text set element symbol */
 204 #define N_SETD  0x18            /* Data set element symbol */
 205 #define N_SETB  0x1A            /* Bss set element symbol */
 206
 207 /* This is output from LD.  */
 208 #define N_SETV  0x1C            /* Pointer to set vector in data area.  */
 209
 210 /* Warning symbol. The text gives a warning message, the next symbol
 211    in the table will be undefined. When the symbol is referenced, the
 212    message is printed.  */
 213
 214 #define N_WARNING 0x1e
 215 \f
 216 /* This structure describes a single relocation to be performed.
 217    The text-relocation section of the file is a vector of these structures,
 218    all of which apply to the text section.
 219    Likewise, the data-relocation section applies to the data section.  */
 220
 221 /* The following enum and struct were borrowed from SunOS's
 222    /usr/include/sun4/a.out.h  and extended to handle
 223    other machines.  It is currently used on SPARC and AMD 29000.
 224
 225    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
 226    how we might process it on a native host.  */
 227
 228 struct reloc_ext_bytes {
 229   unsigned char r_address[4];
 230   unsigned char r_index[3];
 231   unsigned char r_bits[1];
 232   unsigned char r_addend[4];
 233 };
 234
 235 #define RELOC_EXT_BITS_EXTERN_BIG       0x80
 236 #define RELOC_EXT_BITS_EXTERN_LITTLE    0x01
 237
 238 #define RELOC_EXT_BITS_TYPE_BIG         0x1F
 239 #define RELOC_EXT_BITS_TYPE_SH_BIG      0
 240 #define RELOC_EXT_BITS_TYPE_LITTLE      0xF8
 241 #define RELOC_EXT_BITS_TYPE_SH_LITTLE   3
 242
 243 #define RELOC_EXT_SIZE  12              /* Bytes per relocation entry */
 244
 245 struct reloc_info_extended
 246 {
 247   unsigned long r_address;
 248   unsigned int  r_index:24;
 249 # define        r_symbolnum  r_index
 250   unsigned      r_extern:1;
 251   unsigned      :2;
 252   enum reloc_type r_type:5;
 253   long int      r_addend;
 254 };
 255
 256 /* The standard, old-fashioned, Berkeley compatible relocation struct */
 257
 258 struct reloc_std_bytes {
 259   unsigned char r_address[4];
 260   unsigned char r_index[3];
 261   unsigned char r_bits[1];
 262 };
 263
 264 #define RELOC_STD_BITS_PCREL_BIG        0x80
 265 #define RELOC_STD_BITS_PCREL_LITTLE     0x01
 266
 267 #define RELOC_STD_BITS_LENGTH_BIG       0x60
 268 #define RELOC_STD_BITS_LENGTH_SH_BIG    5       /* To shift to units place */
 269 #define RELOC_STD_BITS_LENGTH_LITTLE    0x06
 270 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
 271
 272 #define RELOC_STD_BITS_EXTERN_BIG       0x10
 273 #define RELOC_STD_BITS_EXTERN_LITTLE    0x08
 274
 275 #define RELOC_STD_BITS_BASEREL_BIG      0x08
 276 #define RELOC_STD_BITS_BASEREL_LITTLE   0x08
 277
 278 #define RELOC_STD_BITS_JMPTABLE_BIG     0x04
 279 #define RELOC_STD_BITS_JMPTABLE_LITTLE  0x04
 280
 281 #define RELOC_STD_BITS_RELATIVE_BIG     0x02
 282 #define RELOC_STD_BITS_RELATIVE_LITTLE  0x02
 283
 284 #define RELOC_STD_SIZE  8               /* Bytes per relocation entry */
 285
 286 struct relocation_info
 287 {
 288   /* Address (within segment) to be relocated.  */
 289   int r_address;
 290   /* The meaning of r_symbolnum depends on r_extern.  */
 291   unsigned int r_symbolnum:24;
 292   /* Nonzero means value is a pc-relative offset
 293      and it should be relocated for changes in its own address
 294      as well as for changes in the symbol or section specified.  */
 295   unsigned int r_pcrel:1;
 296   /* Length (as exponent of 2) of the field to be relocated.
 297      Thus, a value of 2 indicates 1<<2 bytes.  */
 298   unsigned int r_length:2;
 299   /* 1 => relocate with value of symbol.
 300           r_symbolnum is the index of the symbol
 301           in file's the symbol table.
 302      0 => relocate with the address of a segment.
 303           r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
 304           (the N_EXT bit may be set also, but signifies nothing).  */
 305   unsigned int r_extern:1;
 306   /* The next three bits are for SunOS shared libraries, and seem to
 307      be undocumented.  */
 308   unsigned int r_baserel:1;     /* Linkage table relative */
 309   unsigned int r_jmptable:1;    /* pc-relative to jump table */
 310
 311 #ifdef TC_NS32K
 312 #define r_bsr   r_baserel
 313 #define r_disp  r_jmptable
 314 #endif /* TC_NS32K */
 315
 316   unsigned int r_relative:1;    /* "relative relocation" */
 317   /* unused */
 318   unsigned int r_pad:1;         /* Padding -- set to zero */
 319 };
 320
 321 #endif /* __A_OUT_GNU_H__ */