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 };
  59
  60 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
  61 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
  62 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
  63 #define N_SET_INFO(exec, magic, type, flags) \
  64         ((exec).a_info = ((magic) & 0xffff) \
  65          | (((int)(type) & 0xff) << 16) \
  66          | (((flags) & 0xff) << 24))
  67 #define N_SET_MAGIC(exec, magic) \
  68         ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
  69
  70 #define N_SET_MACHTYPE(exec, machtype) \
  71         ((exec).a_info = \
  72          ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
  73
  74 #define N_SET_FLAGS(exec, flags) \
  75         ((exec).a_info = \
  76          ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
  77
  78 /* Code indicating object file or impure executable.  */
  79 #define OMAGIC 0407
  80 /* Code indicating pure executable.  */
  81 #define NMAGIC 0410
  82 /* Code indicating demand-paged executable.  */
  83 #define ZMAGIC 0413
  84
  85 /* Address of text segment in memory after it is loaded.  */
  86 /* Don't load things at zero, it encourages zero-pointer bugs */
  87 #ifndef TEXT_START_ADDR
  88 #define TEXT_START_ADDR 0x10000
  89 #endif
  90
  91 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
  92    (almost always "unlinked .o's" these days), should be zero.
  93    Sun added a kludge so that shared libraries linked ZMAGIC get
  94    an address of zero if a_entry (!!!) is lower than the otherwise
  95    expected text address.  These kludges have gotta go!
  96    For linked files, should reflect reality if we know it.  */
  97
  98 #ifndef N_TXTADDR
  99 #define N_TXTADDR(x) \
 100     (N_MAGIC(x)==OMAGIC? 0 \
 101      : (N_MAGIC(x) == ZMAGIC && (x).a_entry < TEXT_START_ADDR)? 0 \
 102      : TEXT_START_ADDR)
 103 #endif
 104
 105 /* Address of data segment in memory after it is loaded.
 106    Note that it is up to you to define SEGMENT_SIZE
 107    on machines not listed here.  */
 108 #if defined(hp300) || defined(pyr)
 109 #define SEGMENT_SIZE page_size
 110 #endif
 111 #ifdef  sony
 112 #define SEGMENT_SIZE    0x2000
 113 #endif  /* Sony.  */
 114 #ifdef is68k
 115 #define SEGMENT_SIZE 0x20000
 116 #endif
 117 #if defined(m68k) && defined(PORTAR)
 118 #define PAGE_SIZE 0x400
 119 #define SEGMENT_SIZE PAGE_SIZE
 120 #endif
 121
 122 #ifndef N_DATADDR
 123 #define N_DATADDR(x) \
 124     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
 125      :  (SEGMENT_SIZE + ((N_TXTADDR(x)+(x).a_text-1) & ~(SEGMENT_SIZE-1))))
 126 #endif
 127
 128 /* Address of bss segment in memory after it is loaded.  */
 129 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
 130 \f
 131 struct nlist {
 132   union {
 133     char *n_name;
 134     struct nlist *n_next;
 135     long n_strx;
 136   } n_un;
 137   unsigned char n_type;
 138   char n_other;
 139   short n_desc;
 140   unsigned long n_value;
 141 };
 142
 143 #define N_UNDF 0
 144 #define N_ABS 2
 145 #define N_TEXT 4
 146 #define N_DATA 6
 147 #define N_BSS 8
 148 #define N_FN 15
 149
 150 #define N_EXT 1
 151 #define N_TYPE 036
 152 #define N_STAB 0340
 153
 154 /* The following type indicates the definition of a symbol as being
 155    an indirect reference to another symbol.  The other symbol
 156    appears as an undefined reference, immediately following this symbol.
 157
 158    Indirection is asymmetrical.  The other symbol's value will be used
 159    to satisfy requests for the indirect symbol, but not vice versa.
 160    If the other symbol does not have a definition, libraries will
 161    be searched to find a definition.  */
 162 #define N_INDR 0xa
 163
 164 /* The following symbols refer to set elements.
 165    All the N_SET[ATDB] symbols with the same name form one set.
 166    Space is allocated for the set in the text section, and each set
 167    element's value is stored into one word of the space.
 168    The first word of the space is the length of the set (number of elements).
 169
 170    The address of the set is made into an N_SETV symbol
 171    whose name is the same as the name of the set.
 172    This symbol acts like a N_DATA global symbol
 173    in that it can satisfy undefined external references.  */
 174
 175 /* These appear as input to LD, in a .o file.  */
 176 #define N_SETA  0x14            /* Absolute set element symbol */
 177 #define N_SETT  0x16            /* Text set element symbol */
 178 #define N_SETD  0x18            /* Data set element symbol */
 179 #define N_SETB  0x1A            /* Bss set element symbol */
 180
 181 /* This is output from LD.  */
 182 #define N_SETV  0x1C            /* Pointer to set vector in data area.  */
 183 \f
 184 /* This structure describes a single relocation to be performed.
 185    The text-relocation section of the file is a vector of these structures,
 186    all of which apply to the text section.
 187    Likewise, the data-relocation section applies to the data section.  */
 188
 189 /* The following enum and struct were borrowed from SunOS's
 190    /usr/include/sun4/a.out.h  and extended to handle
 191    other machines.  It is currently used on SPARC and AMD 29000.
 192
 193    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
 194    how we might process it on a native host.  */
 195
 196 struct reloc_ext_bytes {
 197   unsigned char r_address[4];
 198   unsigned char r_index[3];
 199   unsigned char r_bits[1];
 200   unsigned char r_addend[4];
 201 };
 202
 203 #define RELOC_EXT_BITS_EXTERN_BIG       0x80
 204 #define RELOC_EXT_BITS_EXTERN_LITTLE    0x01
 205
 206 #define RELOC_EXT_BITS_TYPE_BIG         0x1F
 207 #define RELOC_EXT_BITS_TYPE_SH_BIG      0
 208 #define RELOC_EXT_BITS_TYPE_LITTLE      0xF8
 209 #define RELOC_EXT_BITS_TYPE_SH_LITTLE   3
 210
 211 #define RELOC_EXT_SIZE  12              /* Bytes per relocation entry */
 212
 213 struct reloc_info_extended
 214 {
 215   unsigned long r_address;
 216   unsigned int  r_index:24;
 217 # define        r_symbolnum  r_index
 218   unsigned      r_extern:1;
 219   unsigned      :2;
 220   enum reloc_type r_type:5;
 221   long int      r_addend;
 222 };
 223
 224 /* The standard, old-fashioned, Berkeley compatible relocation struct */
 225
 226 struct reloc_std_bytes {
 227   unsigned char r_address[4];
 228   unsigned char r_index[3];
 229   unsigned char r_bits[1];
 230 };
 231
 232 #define RELOC_STD_BITS_PCREL_BIG        0x80
 233 #define RELOC_STD_BITS_PCREL_LITTLE     0x01
 234
 235 #define RELOC_STD_BITS_LENGTH_BIG       0x60
 236 #define RELOC_STD_BITS_LENGTH_SH_BIG    5       /* To shift to units place */
 237 #define RELOC_STD_BITS_LENGTH_LITTLE    0x06
 238 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
 239
 240 #define RELOC_STD_BITS_EXTERN_BIG       0x10
 241 #define RELOC_STD_BITS_EXTERN_LITTLE    0x08
 242
 243 #define RELOC_STD_BITS_BASEREL_BIG      0x08
 244 #define RELOC_STD_BITS_BASEREL_LITTLE   0x08
 245
 246 #define RELOC_STD_BITS_JMPTABLE_BIG     0x04
 247 #define RELOC_STD_BITS_JMPTABLE_LITTLE  0x04
 248
 249 #define RELOC_STD_BITS_RELATIVE_BIG     0x02
 250 #define RELOC_STD_BITS_RELATIVE_LITTLE  0x02
 251
 252 #define RELOC_STD_SIZE  8               /* Bytes per relocation entry */
 253
 254 struct relocation_info
 255 {
 256   /* Address (within segment) to be relocated.  */
 257   int r_address;
 258   /* The meaning of r_symbolnum depends on r_extern.  */
 259   unsigned int r_symbolnum:24;
 260   /* Nonzero means value is a pc-relative offset
 261      and it should be relocated for changes in its own address
 262      as well as for changes in the symbol or section specified.  */
 263   unsigned int r_pcrel:1;
 264   /* Length (as exponent of 2) of the field to be relocated.
 265      Thus, a value of 2 indicates 1<<2 bytes.  */
 266   unsigned int r_length:2;
 267   /* 1 => relocate with value of symbol.
 268           r_symbolnum is the index of the symbol
 269           in file's the symbol table.
 270      0 => relocate with the address of a segment.
 271           r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
 272           (the N_EXT bit may be set also, but signifies nothing).  */
 273   unsigned int r_extern:1;
 274   /* The next three bits are for SunOS shared libraries, and seem to
 275      be undocumented.  */
 276   unsigned int r_baserel:1;     /* Linkage table relative */
 277   unsigned int r_jmptable:1;    /* pc-relative to jump table */
 278   unsigned int r_relative:1;    /* "relative relocation" */
 279   /* unused */
 280   unsigned int r_pad:1;         /* Padding -- set to zero */
 281 };
 282
 283 #endif /* __A_OUT_GNU_H__ */