a.out.h

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#ifndef __A_OUT_GNU_H__
#define __A_OUT_GNU_H__

#define __GNU_EXEC_MACROS__

#ifndef __STRUCT_EXEC_OVERRIDE__

struct exec
{
  unsigned long a_info;         ///< Use macros N_MAGIC, etc for access 
  unsigned a_text;              ///< length of text, in bytes 
  unsigned a_data;              ///< length of data, in bytes 
  unsigned a_bss;               ///< length of uninitialized data area for file, in bytes 
  unsigned a_syms;              ///< length of symbol table data in file, in bytes 
  unsigned a_entry;             ///< start address 
  unsigned a_trsize;            ///< length of relocation info for text, in bytes 
  unsigned a_drsize;            ///< length of relocation info for data, in bytes 
};

#endif // __STRUCT_EXEC_OVERRIDE__ 

/// these go in the N_MACHTYPE field 
enum machine_type {
#if defined (M_OLDSUN2)
  M__OLDSUN2 = M_OLDSUN2,
#else
  M_OLDSUN2 = 0,
#endif
#if defined (M_68010)
  M__68010 = M_68010,
#else
  M_68010 = 1,
#endif
#if defined (M_68020)
  M__68020 = M_68020,
#else
  M_68020 = 2,
#endif
#if defined (M_SPARC)
  M__SPARC = M_SPARC,
#else
  M_SPARC = 3,
#endif
  /// skip a bunch so we don't run into any of sun's numbers 
  M_386 = 100,
};

#if !defined (N_MAGIC)
#define N_MAGIC(exec) ((exec).a_info & 0xffff)
#endif
#define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
#define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
#define N_SET_INFO(exec, magic, type, flags) \
        ((exec).a_info = ((magic) & 0xffff) \
         | (((int)(type) & 0xff) << 16) \
         | (((flags) & 0xff) << 24))
#define N_SET_MAGIC(exec, magic) \
        ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))

#define N_SET_MACHTYPE(exec, machtype) \
        ((exec).a_info = \
         ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))

#define N_SET_FLAGS(exec, flags) \
        ((exec).a_info = \
         ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))

/// Code indicating object file or impure executable.  
#define OMAGIC 0407
/// Code indicating pure executable.  
#define NMAGIC 0410
/// Code indicating demand-paged executable.  
#define ZMAGIC 0413
/**
*
 This indicates a demand-paged executable with the header in the text. 


*/
#define QMAGIC 0314

/// Code indicating core file.  
#define CMAGIC 0421

#if !defined (N_BADMAG)
#define N_BADMAG(x)       (N_MAGIC(x) != OMAGIC         \
                        && N_MAGIC(x) != NMAGIC         \
                        && N_MAGIC(x) != ZMAGIC \
                        && N_MAGIC(x) != QMAGIC)
#endif

#define _N_HDROFF(x) (1024 - sizeof (struct exec))

#if !defined (N_TXTOFF)
#define N_TXTOFF(x) \
 (N_MAGIC(x) == ZMAGIC ? _N_HDROFF((x)) + sizeof (struct exec) : \
  (N_MAGIC(x) == QMAGIC ? 0 : sizeof (struct exec)))
#endif

#if !defined (N_DATOFF)
#define N_DATOFF(x) (N_TXTOFF(x) + (x).a_text)
#endif

#if !defined (N_TRELOFF)
#define N_TRELOFF(x) (N_DATOFF(x) + (x).a_data)
#endif

#if !defined (N_DRELOFF)
#define N_DRELOFF(x) (N_TRELOFF(x) + (x).a_trsize)
#endif

#if !defined (N_SYMOFF)
#define N_SYMOFF(x) (N_DRELOFF(x) + (x).a_drsize)
#endif

#if !defined (N_STROFF)
#define N_STROFF(x) (N_SYMOFF(x) + (x).a_syms)
#endif

/// Address of text segment in memory after it is loaded.  
#if !defined (N_TXTADDR)
#define N_TXTADDR(x) (N_MAGIC(x) == QMAGIC ? PAGE_SIZE : 0)
#endif

/**
*
 Address of data segment in memory after it is loaded.
   Note that it is up to you to define SEGMENT_SIZE


*/
#if defined(vax) || defined(hp300) || defined(pyr)
#define SEGMENT_SIZE page_size
#endif
#ifdef  sony
#define SEGMENT_SIZE    0x2000
#endif  // Sony.  
#ifdef is68k
#define SEGMENT_SIZE 0x20000
#endif
#if defined(m68k) && defined(PORTAR)
#define PAGE_SIZE 0x400
#define SEGMENT_SIZE PAGE_SIZE
#endif

#ifdef linux
#include <linux/page.h>
#define SEGMENT_SIZE    1024
#endif

#define _N_SEGMENT_ROUND(x) (((x) + SEGMENT_SIZE - 1) & ~(SEGMENT_SIZE - 1))

#define _N_TXTENDADDR(x) (N_TXTADDR(x)+(x).a_text)

#ifndef N_DATADDR
#define N_DATADDR(x) \
    (N_MAGIC(x)==OMAGIC? (_N_TXTENDADDR(x)) \
     : (_N_SEGMENT_ROUND (_N_TXTENDADDR(x))))
#endif

/// Address of bss segment in memory after it is loaded.  
#if !defined (N_BSSADDR)
#define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
#endif

#if !defined (N_NLIST_DECLARED)
struct nlist {
  union {
    char *n_name;
    struct nlist *n_next;
    long n_strx;
  } n_un;
  unsigned char n_type;
  char n_other;
  short n_desc;
  unsigned long n_value;
};
#endif // no N_NLIST_DECLARED.  

#if !defined (N_UNDF)
#define N_UNDF 0
#endif
#if !defined (N_ABS)
#define N_ABS 2
#endif
#if !defined (N_TEXT)
#define N_TEXT 4
#endif
#if !defined (N_DATA)
#define N_DATA 6
#endif
#if !defined (N_BSS)
#define N_BSS 8
#endif
#if !defined (N_FN)
#define N_FN 15
#endif

#if !defined (N_EXT)
#define N_EXT 1
#endif
#if !defined (N_TYPE)
#define N_TYPE 036
#endif
#if !defined (N_STAB)
#define N_STAB 0340
#endif

/**
*
 The following type indicates the definition of a symbol as being
   an indirect reference to another symbol.  The other symbol
   appears as an undefined reference, immediately following this symbol.

   Indirection is asymmetrical.  The other symbol's value will be used
   to satisfy requests for the indirect symbol, but not vice versa.
   If the other symbol does not have a definition, libraries will


*/
#define N_INDR 0xa

/**
*
 The following symbols refer to set elements.
   All the N_SET[ATDB] symbols with the same name form one set.
   Space is allocated for the set in the text section, and each set
   element's value is stored into one word of the space.
   The first word of the space is the length of the set (number of elements).

   The address of the set is made into an N_SETV symbol
   whose name is the same as the name of the set.
   This symbol acts like a N_DATA global symbol


*/

/// These appear as input to LD, in a .o file.  
#define N_SETA  0x14            ///< Absolute set element symbol 
#define N_SETT  0x16            ///< Text set element symbol 
#define N_SETD  0x18            ///< Data set element symbol 
#define N_SETB  0x1A            ///< Bss set element symbol 

/// This is output from LD.  
#define N_SETV  0x1C            ///< Pointer to set vector in data area.  

#if !defined (N_RELOCATION_INFO_DECLARED)
/**
*
 This structure describes a single relocation to be performed.
   The text-relocation section of the file is a vector of these structures,
   all of which apply to the text section.


*/

struct relocation_info
{
  /// Address (within segment) to be relocated.  
  int r_address;
  /// The meaning of r_symbolnum depends on r_extern.  
  unsigned int r_symbolnum:24;
/**
*
 Nonzero means value is a pc-relative offset
     and it should be relocated for changes in its own address


*/
  unsigned int r_pcrel:1;
/**
*
 Length (as exponent of 2) of the field to be relocated.


*/
  unsigned int r_length:2;
/**
*
 1 => relocate with value of symbol.
          r_symbolnum is the index of the symbol
          in file's the symbol table.
     0 => relocate with the address of a segment.
          r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS


*/
  unsigned int r_extern:1;
/**
*
 Four bits that aren't used, but when writing an object file


*/
#ifdef NS32K
  unsigned r_bsr:1;
  unsigned r_disp:1;
  unsigned r_pad:2;
#else
  unsigned int r_pad:4;
#endif
};
#endif // no N_RELOCATION_INFO_DECLARED.  


#endif // __A_OUT_GNU_H__ 

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