[deliverable/binutils-gdb.git] / include / aout / encap.h

/* Yet Another Try at encapsulating bsd object files in coff.
   Copyright (C) 1988, 1989, 1991 Free Software Foundation, Inc.
   Written by Pace Willisson 12/9/88

   This file is obsolete.  It needs to be converted to just define a bunch
   of stuff that BFD can use to do coff-encapsulated files.  --gnu@cygnus.com

This program 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 of the License, or
(at your option) any later version.

This program 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 this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/*
 * We only use the coff headers to tell the kernel
 * how to exec the file.  Therefore, the only fields that need to 
 * be filled in are the scnptr and vaddr for the text and data
 * sections, and the vaddr for the bss.  As far as coff is concerned,
 * there is no symbol table, relocation, or line numbers.
 *
 * A normal bsd header (struct exec) is placed after the coff headers,
 * and before the real text.  I defined a the new fields 'a_machtype'
 * and a_flags.  If a_machtype is M_386, and a_flags & A_ENCAP is
 * true, then the bsd header is preceeded by a coff header.  Macros
 * like N_TXTOFF and N_TXTADDR use this field to find the bsd header.
 * 
 * The only problem is to track down the bsd exec header.  The
 * macros HEADER_OFFSET, etc do this.
 */

#define N_FLAGS_COFF_ENCAPSULATE 0x20 /* coff header precedes bsd header */

/* Describe the COFF header used for encapsulation.  */

struct coffheader
{
  /* filehdr */
  unsigned short f_magic;
  unsigned short f_nscns;
  long f_timdat;
  long f_symptr;
  long f_nsyms;
  unsigned short f_opthdr;
  unsigned short f_flags;
  /* aouthdr */
  short magic;
  short vstamp;
  long tsize;
  long dsize;
  long bsize;
  long entry;
  long text_start;
  long data_start;
  struct coffscn
    {
      char s_name[8];
      long s_paddr;
      long s_vaddr;
      long s_size;
      long s_scnptr;
      long s_relptr;
      long s_lnnoptr;
      unsigned short s_nreloc;
      unsigned short s_nlnno;
      long s_flags;
    } scns[3];
};
\f
/* Describe some of the parameters of the encapsulation,
   including how to find the encapsulated BSD header.  */

/* FIXME, this is dumb.  The same tools can't handle a.outs for different
   architectures, just because COFF_MAGIC is different; so you need a
   separate GNU nm for every architecture!!?  Unfortunately, it needs to
   be this way, since the COFF_MAGIC value is determined by the kernel
   we're trying to fool here.  */
   
#define COFF_MAGIC_I386 0514 /* I386MAGIC */
#define COFF_MAGIC_M68K 0520 /* MC68MAGIC */
#define	COFF_MAGIC_A29K 0x17A	/* Used by asm29k cross-tools */

#ifdef COFF_MAGIC
short __header_offset_temp;
#define HEADER_OFFSET(f) \
	(__header_offset_temp = 0, \
	 fread ((char *)&__header_offset_temp, sizeof (short), 1, (f)), \
	 fseek ((f), -sizeof (short), 1), \
	 __header_offset_temp==COFF_MAGIC ? sizeof(struct coffheader) : 0)
#else
#define HEADER_OFFSET(f) 0
#endif

#define HEADER_SEEK(f) (fseek ((f), HEADER_OFFSET((f)), 1))
\f
/* Describe the characteristics of the BSD header
   that appears inside the encapsulation.  */

/* Encapsulated coff files that are linked ZMAGIC have a text segment
   offset just past the header (and a matching TXTADDR), excluding
   the headers from the text segment proper but keeping the physical
   layout and the virtual memory layout page-aligned.

   Non-encapsulated a.out files that are linked ZMAGIC have a text
   segment that starts at 0 and an N_TXTADR similarly offset to 0.
   They too are page-aligned with each other, but they include the
   a.out header as part of the text. 

   The _N_HDROFF gets sizeof struct exec added to it, so we have
   to compensate here.  See <a.out.gnu.h>.  */

#undef _N_HDROFF
#undef N_TXTADDR
#undef N_DATADDR

#define _N_HDROFF(x) ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \
		      sizeof (struct coffheader) : 0)

/* Address of text segment in memory after it is loaded.  */
#define N_TXTADDR(x) \
	((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \
	 sizeof (struct coffheader) + sizeof (struct exec) : 0)
#define SEGMENT_SIZE 0x400000

#define N_DATADDR(x) \
	((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \
	 (SEGMENT_SIZE + ((N_TXTADDR(x)+(x).a_text-1) & ~(SEGMENT_SIZE-1))) : \
	 (N_TXTADDR(x)+(x).a_text))
Commit	Line	Data
0227e918 SC	1	/* Yet Another Try at encapsulating bsd object files in coff.
	2	Copyright (C) 1988, 1989, 1991 Free Software Foundation, Inc.
	3	Written by Pace Willisson 12/9/88
	4
	5	This file is obsolete. It needs to be converted to just define a bunch
	6	of stuff that BFD can use to do coff-encapsulated files. --gnu@cygnus.com
	7
	8	This program is free software; you can redistribute it and/or modify
	9	it under the terms of the GNU General Public License as published by
	10	the Free Software Foundation; either version 2 of the License, or
	11	(at your option) any later version.
	12
	13	This program is distributed in the hope that it will be useful,
	14	but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	GNU General Public License for more details.
	17
	18	You should have received a copy of the GNU General Public License
	19	along with this program; if not, write to the Free Software
	20	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
	21
	22	/*
	23	* We only use the coff headers to tell the kernel
	24	* how to exec the file. Therefore, the only fields that need to
	25	* be filled in are the scnptr and vaddr for the text and data
	26	* sections, and the vaddr for the bss. As far as coff is concerned,
	27	* there is no symbol table, relocation, or line numbers.
	28	*
	29	* A normal bsd header (struct exec) is placed after the coff headers,
	30	* and before the real text. I defined a the new fields 'a_machtype'
	31	* and a_flags. If a_machtype is M_386, and a_flags & A_ENCAP is
	32	* true, then the bsd header is preceeded by a coff header. Macros
	33	* like N_TXTOFF and N_TXTADDR use this field to find the bsd header.
	34	*
	35	* The only problem is to track down the bsd exec header. The
	36	* macros HEADER_OFFSET, etc do this.
	37	*/
	38
	39	#define N_FLAGS_COFF_ENCAPSULATE 0x20 /* coff header precedes bsd header */
	40
	41	/* Describe the COFF header used for encapsulation. */
	42
	43	struct coffheader
	44	{
	45	/* filehdr */
	46	unsigned short f_magic;
	47	unsigned short f_nscns;
	48	long f_timdat;
	49	long f_symptr;
	50	long f_nsyms;
	51	unsigned short f_opthdr;
	52	unsigned short f_flags;
	53	/* aouthdr */
	54	short magic;
	55	short vstamp;
	56	long tsize;
	57	long dsize;
	58	long bsize;
	59	long entry;
	60	long text_start;
	61	long data_start;
	62	struct coffscn
	63	{
	64	char s_name[8];
65	long s_paddr;
66	long s_vaddr;
67	long s_size;
68	long s_scnptr;
69	long s_relptr;
70	long s_lnnoptr;
71	unsigned short s_nreloc;
72	unsigned short s_nlnno;
73	long s_flags;
74	} scns[3];
75	};
76	\f
77	/* Describe some of the parameters of the encapsulation,
78	including how to find the encapsulated BSD header. */
79
80	/* FIXME, this is dumb. The same tools can't handle a.outs for different
81	architectures, just because COFF_MAGIC is different; so you need a
82	separate GNU nm for every architecture!!? Unfortunately, it needs to
83	be this way, since the COFF_MAGIC value is determined by the kernel
84	we're trying to fool here. */
85
86	#define COFF_MAGIC_I386 0514 /* I386MAGIC */
87	#define COFF_MAGIC_M68K 0520 /* MC68MAGIC */
88	#define COFF_MAGIC_A29K 0x17A /* Used by asm29k cross-tools */
89
90	#ifdef COFF_MAGIC
91	short __header_offset_temp;
92	#define HEADER_OFFSET(f) \
93	(__header_offset_temp = 0, \
94	fread ((char *)&__header_offset_temp, sizeof (short), 1, (f)), \
95	fseek ((f), -sizeof (short), 1), \
96	__header_offset_temp==COFF_MAGIC ? sizeof(struct coffheader) : 0)
97	#else
98	#define HEADER_OFFSET(f) 0
99	#endif
100
101	#define HEADER_SEEK(f) (fseek ((f), HEADER_OFFSET((f)), 1))
102	\f
103	/* Describe the characteristics of the BSD header
104	that appears inside the encapsulation. */
105
106	/* Encapsulated coff files that are linked ZMAGIC have a text segment
107	offset just past the header (and a matching TXTADDR), excluding
108	the headers from the text segment proper but keeping the physical
109	layout and the virtual memory layout page-aligned.
110
111	Non-encapsulated a.out files that are linked ZMAGIC have a text
112	segment that starts at 0 and an N_TXTADR similarly offset to 0.
113	They too are page-aligned with each other, but they include the
114	a.out header as part of the text.
115
116	The _N_HDROFF gets sizeof struct exec added to it, so we have
117	to compensate here. See <a.out.gnu.h>. */
118
119	#undef _N_HDROFF
120	#undef N_TXTADDR
121	#undef N_DATADDR
122
123	#define _N_HDROFF(x) ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \
124	sizeof (struct coffheader) : 0)
125
126	/* Address of text segment in memory after it is loaded. */
127	#define N_TXTADDR(x) \
128	((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \
129	sizeof (struct coffheader) + sizeof (struct exec) : 0)
130	#define SEGMENT_SIZE 0x400000
131
132	#define N_DATADDR(x) \
133	((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \
134	(SEGMENT_SIZE + ((N_TXTADDR(x)+(x).a_text-1) & ~(SEGMENT_SIZE-1))) : \
135	(N_TXTADDR(x)+(x).a_text))