mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-10 03:54:48 +00:00
136 lines
4.6 KiB
C
136 lines
4.6 KiB
C
/* Yet Another Try at encapsulating bfd object files in coff.
|
||
Copyright 1988, 1989, 1991, 2010 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This file is obsolete.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 3 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., 51 Franklin Street - Fifth Floor, Boston,
|
||
MA 02110-1301, 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];
|
||
};
|
||
|
||
/* 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 */
|
||
|
||
#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))
|
||
|
||
/* 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))
|