path: root/gas/config/obj-bout.h

/* b.out object file format
   Copyright (C) 1989, 90, 91, 92, 93, 94, 95, 1996
   Free Software Foundation, Inc.

   This file is part of GAS, the GNU Assembler.

   GAS is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2,
   or (at your option) any later version.

   GAS is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   the GNU General Public License for more details.

   You should have received a copy of the GNU General Public
   License along with GAS; see the file COPYING.  If not, write
   to the Free Software Foundation, 59 Temple Place - Suite 330, Cambridge, MA
   02139, USA. */

/*
 * This file is a modified version of 'a.out.h'.  It is to be used in all GNU
 * tools modified to support the i80960 b.out format (or tools that operate on
 * object files created by such tools).
 *
 * All i80960 development is done in a CROSS-DEVELOPMENT environment.  I.e.,
 * object code is generated on, and executed under the direction of a symbolic
 * debugger running on, a host system.  We do not want to be subject to the
 * vagaries of which host it is or whether it supports COFF or a.out format, or
 * anything else.  We DO want to:
 *
 *	o always generate the same format object files, regardless of host.
 *
 *	o have an 'a.out' header that we can modify for our own purposes
 *	  (the 80960 is typically an embedded processor and may require
 *	  enhanced linker support that the normal a.out.h header can't
 *	  accommodate).
 *
 * As for byte-ordering, the following rules apply:
 *
 *	o Text and data that is actually downloaded to the target is always
 *	  in i80960 (little-endian) order.
 *
 *	o All other numbers (in the header, symbols, relocation directives)
 *	  are in host byte-order:  object files CANNOT be lifted from a
 *	  little-end host and used on a big-endian (or vice versa) without
 *	  modification.
 * ==> THIS IS NO LONGER TRUE USING BFD.  WE CAN GENERATE ANY BYTE ORDER
 *     FOR THE HEADER, AND READ ANY BYTE ORDER.  PREFERENCE WOULD BE TO
 *     USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST.  <==
 *
 *	o The downloader ('comm960') takes care to generate a pseudo-header
 *	  with correct (i80960) byte-ordering before shipping text and data
 *	  off to the NINDY monitor in the target systems.  Symbols and
 *	  relocation info are never sent to the target.
 */


#define OBJ_BOUT 1

#define OUTPUT_FLAVOR bfd_target_aout_flavour

#include "targ-cpu.h"

#define OBJ_DEFAULT_OUTPUT_FILE_NAME	"b.out"

extern const short seg_N_TYPE[];
extern const segT N_TYPE_seg[];

#define BMAGIC	0415
/* We don't accept the following (see N_BADMAG macro).
 * They're just here so GNU code will compile.
 */
#define	OMAGIC	0407		/* old impure format */
#define	NMAGIC	0410		/* read-only text */
#define	ZMAGIC	0413		/* demand load format */

#ifndef DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE
#define DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE	(BMAGIC)
#endif /* DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE */

/* FILE HEADER
 *	All 'lengths' are given as a number of bytes.
 *	All 'alignments' are for relinkable files only;  an alignment of
 *		'n' indicates the corresponding segment must begin at an
 *		address that is a multiple of (2**n).
 */
struct exec
  {
    /* Standard stuff */
    unsigned long a_magic;	/* Identifies this as a b.out file	*/
    unsigned long a_text;	/* Length of text			*/
    unsigned long a_data;	/* Length of data			*/
    unsigned long a_bss;	/* Length of runtime uninitialized data area */
    unsigned long a_syms;	/* Length of symbol table		*/
    unsigned long a_entry;	/* Runtime start address		*/
    unsigned long a_trsize;	/* Length of text relocation info	*/
    unsigned long a_drsize;	/* Length of data relocation info	*/

    /* Added for i960 */
    unsigned long a_tload;	/* Text runtime load address		*/
    unsigned long a_dload;	/* Data runtime load address		*/
    unsigned char a_talign;	/* Alignment of text segment		*/
    unsigned char a_dalign;	/* Alignment of data segment		*/
    unsigned char a_balign;	/* Alignment of bss segment		*/
    unsigned char a_relaxable;	/* Contains enough info to relax     */
  };

#define N_BADMAG(x)	(((x).a_magic)!=BMAGIC)
#define N_TXTOFF(x)	( sizeof(struct exec) )
#define N_DATOFF(x)	( N_TXTOFF(x) + (x).a_text )
#define N_TROFF(x)	( N_DATOFF(x) + (x).a_data )
#define N_DROFF(x)	( N_TROFF(x) + (x).a_trsize )
#define N_SYMOFF(x)	( N_DROFF(x) + (x).a_drsize )
#define N_STROFF(x)	( N_SYMOFF(x) + (x).a_syms )

/* A single entry in the symbol table
 */
struct nlist
  {
    union
      {
	char *n_name;
	struct nlist *n_next;
	long n_strx;		/* Index into string table	*/
      }
    n_un;
    unsigned char n_type;	/* See below				*/
    char n_other;		/* Used in i80960 support -- see below	*/
    short n_desc;
    unsigned long n_value;
  };

typedef struct nlist obj_symbol_type;

/* Legal values of n_type
 */
#define N_UNDF	0		/* Undefined symbol	*/
#define N_ABS	2		/* Absolute symbol	*/
#define N_TEXT	4		/* Text symbol		*/
#define N_DATA	6		/* Data symbol		*/
#define N_BSS	8		/* BSS symbol		*/
#define N_FN	31		/* Filename symbol	*/

#define N_EXT	1		/* External symbol (OR'd in with one of above)	*/
#define N_TYPE	036		/* Mask for all the type bits			*/
#define N_STAB	0340		/* Mask for all bits used for SDB entries 	*/

#ifndef CUSTOM_RELOC_FORMAT
struct relocation_info
  {
    int r_address;		/* File address of item to be relocated	*/
    unsigned
      r_index:24,		/* Index of symbol on which relocation is based*/
      r_pcrel:1,		/* 1 => relocate PC-relative; else absolute
		 *	On i960, pc-relative implies 24-bit
		 *	address, absolute implies 32-bit.
		 */
      r_length:2,		/* Number of bytes to relocate:
		 *	0 => 1 byte
		 *	1 => 2 bytes
		 *	2 => 4 bytes -- only value used for i960
		 */
      r_extern:1, r_bsr:1,	/* Something for the GNU NS32K assembler */
      r_disp:1,			/* Something for the GNU NS32K assembler */
      r_callj:1,		/* 1 if relocation target is an i960 'callj' */
      nuthin:1;			/* Unused				*/
  };

#endif /* CUSTOM_RELOC_FORMAT */

/*
 *  Macros to extract information from a symbol table entry.
 *  This syntaxic indirection allows independence regarding a.out or coff.
 *  The argument (s) of all these macros is a pointer to a symbol table entry.
 */

/* Predicates */
/* True if the symbol is external */
#define S_IS_EXTERNAL(s)	((s)->sy_symbol.n_type & N_EXT)

/* True if symbol has been defined, ie is in N_{TEXT,DATA,BSS,ABS} or N_EXT */
#define S_IS_DEFINED(s)		((S_GET_TYPE(s) != N_UNDF) || (S_GET_DESC(s) != 0))

#define S_IS_COMMON(s) \
  (S_GET_TYPE (s) == N_UNDF && S_GET_VALUE (s) != 0)

#define S_IS_REGISTER(s)	((s)->sy_symbol.n_type == N_REGISTER)

/* True if a debug special symbol entry */
#define S_IS_DEBUG(s)		((s)->sy_symbol.n_type & N_STAB)
/* True if a symbol is local symbol name */
#define S_IS_LOCAL(s) 					\
  ((S_GET_NAME (s) 					\
    && !S_IS_DEBUG (s) 					\
    && (strchr (S_GET_NAME (s), '\001') != NULL		\
        || strchr (S_GET_NAME (s), '\002') != NULL	\
        || (S_LOCAL_NAME(s) && !flag_keep_locals)))	\
   || (flag_strip_local_absolute			\
       && !S_IS_EXTERNAL(s)				\
       && S_GET_SEGMENT(s) == absolute_section))
/* True if a symbol is not defined in this file */
#define S_IS_EXTERN(s)		((s)->sy_symbol.n_type & N_EXT)
/* True if the symbol has been generated because of a .stabd directive */
#define S_IS_STABD(s)		(S_GET_NAME(s) == NULL)

/* Accessors */
/* The name of the symbol */
#define S_GET_NAME(s)		((s)->sy_symbol.n_un.n_name)
/* The pointer to the string table */
#define S_GET_OFFSET(s)		((s)->sy_symbol.n_un.n_strx)
/* The type of the symbol */
#define S_GET_TYPE(s)		((s)->sy_symbol.n_type & N_TYPE)
/* The numeric value of the segment */
#define S_GET_SEGMENT(s)	(N_TYPE_seg[S_GET_TYPE(s)])
/* The n_other expression value */
#define S_GET_OTHER(s)		((s)->sy_symbol.n_other)
/* The n_desc expression value */
#define S_GET_DESC(s)		((s)->sy_symbol.n_desc)

/* Modifiers */
/* Assume that a symbol cannot be simultaneously in more than on segment */
/* set segment */
#define S_SET_SEGMENT(s,seg)	((s)->sy_symbol.n_type &= ~N_TYPE,(s)->sy_symbol.n_type|=SEGMENT_TO_SYMBOL_TYPE(seg))
/* The symbol is external */
#define S_SET_EXTERNAL(s)	((s)->sy_symbol.n_type |= N_EXT)
/* The symbol is not external */
#define S_CLEAR_EXTERNAL(s)	((s)->sy_symbol.n_type &= ~N_EXT)
/* Set the name of the symbol */
#define S_SET_NAME(s,v)		((s)->sy_symbol.n_un.n_name = (v))
/* Set the offset in the string table */
#define S_SET_OFFSET(s,v)	((s)->sy_symbol.n_un.n_strx = (v))
/* Set the n_other expression value */
#define S_SET_OTHER(s,v)	((s)->sy_symbol.n_other = (v))
/* Set the n_desc expression value */
#define S_SET_DESC(s,v)		((s)->sy_symbol.n_desc = (v))
/* Set the n_type value */
#define S_SET_TYPE(s,v)		((s)->sy_symbol.n_type = (v))

/* File header macro and type definition */

#define H_GET_FILE_SIZE(h)	(sizeof(struct exec) + \
				 H_GET_TEXT_SIZE(h) + H_GET_DATA_SIZE(h) + \
				 H_GET_SYMBOL_TABLE_SIZE(h) + \
				 H_GET_TEXT_RELOCATION_SIZE(h) + \
				 H_GET_DATA_RELOCATION_SIZE(h) + \
				 (h)->string_table_size)

#define H_GET_HEADER_SIZE(h)		(sizeof(struct exec))
#define H_GET_TEXT_SIZE(h)		((h)->header.a_text)
#define H_GET_DATA_SIZE(h)		((h)->header.a_data)
#define H_GET_BSS_SIZE(h)		((h)->header.a_bss)
#define H_GET_TEXT_RELOCATION_SIZE(h)	((h)->header.a_trsize)
#define H_GET_DATA_RELOCATION_SIZE(h)	((h)->header.a_drsize)
#define H_GET_SYMBOL_TABLE_SIZE(h)	((h)->header.a_syms)
#define H_GET_MAGIC_NUMBER(h)		((h)->header.a_info)
#define H_GET_ENTRY_POINT(h)		((h)->header.a_entry)
#define H_GET_STRING_SIZE(h)		((h)->string_table_size)
#define H_GET_LINENO_SIZE(h)		(0)

#ifdef EXEC_MACHINE_TYPE
#define H_GET_MACHINE_TYPE(h)		((h)->header.a_machtype)
#endif /* EXEC_MACHINE_TYPE */
#ifdef EXEC_VERSION
#define H_GET_VERSION(h)		((h)->header.a_version)
#endif /* EXEC_VERSION */

#define H_SET_TEXT_SIZE(h,v)		((h)->header.a_text = (v))
#define H_SET_DATA_SIZE(h,v)		((h)->header.a_data = (v))
#define H_SET_BSS_SIZE(h,v)		((h)->header.a_bss = (v))

#define H_SET_RELOCATION_SIZE(h,t,d)	(H_SET_TEXT_RELOCATION_SIZE((h),(t)),\
					 H_SET_DATA_RELOCATION_SIZE((h),(d)))

#define H_SET_TEXT_RELOCATION_SIZE(h,v)	((h)->header.a_trsize = (v))
#define H_SET_DATA_RELOCATION_SIZE(h,v)	((h)->header.a_drsize = (v))
#define H_SET_SYMBOL_TABLE_SIZE(h,v)	((h)->header.a_syms = (v) * \
					 sizeof(struct nlist))

#define H_SET_MAGIC_NUMBER(h,v)		((h)->header.a_magic = (v))

#define H_SET_ENTRY_POINT(h,v)		((h)->header.a_entry = (v))
#define H_SET_STRING_SIZE(h,v)		((h)->string_table_size = (v))
#ifdef EXEC_MACHINE_TYPE
#define H_SET_MACHINE_TYPE(h,v)		((h)->header.a_machtype = (v))
#endif /* EXEC_MACHINE_TYPE */
#ifdef EXEC_VERSION
#define H_SET_VERSION(h,v)		((h)->header.a_version = (v))
#endif /* EXEC_VERSION */

typedef struct
  {
    struct exec header;		/* a.out header */
    long string_table_size;	/* names + '\0' + sizeof(int) */
  }

object_headers;

/* unused hooks. */
#define OBJ_EMIT_LINENO(a, b, c)	{;}
#define obj_pre_write_hook(a)		{;}

#if __STDC__
struct fix;
#endif
extern void tc_aout_fix_to_chars PARAMS ((char *where,
					  struct fix *fixP,
					  relax_addressT segment_address));
extern void tc_bout_fix_to_chars PARAMS ((char *where,
					  struct fix *fixP,
					  relax_addressT segment_address));

#define AOUT_STABS

/* end of obj-bout.h */