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/* Another try at encapsulating bsd object files in coff.
Copyright (C) 1988, 1989, Free Software Foundation, Inc.
Written by Pace Willisson 12/9/88
This file 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 1, or (at your option)
any later version.
This file 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 file; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/*
* This time, we will 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. Look at nm.c, dis.c, etc
* for examples.
*/
#include "a.out.gnu.h"
#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];
};
/* Describe some of the parameters of the encapsulation,
including how to find the encapsulated BSD header. */
#ifdef i386
#define COFF_MAGIC 0514 /* I386MAGIC */
#endif
#ifdef m68k
#define COFF_MAGIC 0520 /* MC68MAGIC */
#endif
#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)
#define HEADER_OFFSET_FD(fd) \
(__header_offset_temp = 0, \
read ((fd), (char *)&__header_offset_temp, sizeof (short)), \
lseek ((fd), -sizeof (short), 1), \
__header_offset_temp==COFF_MAGIC ? sizeof(struct coffheader) : 0)
#else
#define HEADER_OFFSET(f) 0
#define HEADER_OFFSET_FD(fd) 0
#endif
#define HEADER_SEEK(f) (fseek ((f), HEADER_OFFSET((f)), 1))
#define HEADER_SEEK_FD(fd) (lseek ((fd), HEADER_OFFSET_FD((fd)), 1))
/* Describe the characteristics of the BSD header
that appears inside the encapsulation. */
#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))
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