310 lines
12 KiB
C
310 lines
12 KiB
C
/* b.out object file format
|
|
Copyright 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 2000,
|
|
2002, 2003, 2005 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, 51 Franklin Street - Fifth Floor, 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
|
|
|
|
/* 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 EXEC_BYTES_SIZE (10 * 4 + 4 * 1)
|
|
|
|
#define N_BADMAG(x) (((x).a_magic) != BMAGIC)
|
|
#define N_TXTOFF(x) EXEC_BYTES_SIZE
|
|
#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 syntactic 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))
|
|
|
|
/* Return true for symbols that should not be reduced to section
|
|
symbols or eliminated from expressions, because they may be
|
|
overridden by the linker. */
|
|
#define S_FORCE_RELOC(s, strict) \
|
|
(!SEG_NORMAL (S_GET_SEGMENT (s)))
|
|
|
|
#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 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) (EXEC_BYTES_SIZE \
|
|
+ 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) EXEC_BYTES_SIZE
|
|
#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) * 12)
|
|
|
|
#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 WORDS_BIGENDIAN
|
|
#define host_number_to_chars number_to_chars_bigendian
|
|
#else
|
|
#define host_number_to_chars number_to_chars_littleendian
|
|
#endif
|
|
|
|
struct fix;
|
|
|
|
extern void tc_aout_fix_to_chars (char *, struct fix *, relax_addressT);
|
|
extern void tc_bout_fix_to_chars (char *, struct fix *, relax_addressT);
|
|
|
|
#define AOUT_STABS
|