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[binutils.git] / gas / config / obj-bout.h
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1 /* b.out object file format
2 Copyright 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 2000,
3 2002, 2003 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
7 GAS is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as
9 published by the Free Software Foundation; either version 2,
10 or (at your option) any later version.
12 GAS is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 the GNU General Public License for more details.
17 You should have received a copy of the GNU General Public
18 License along with GAS; see the file COPYING. If not, write
19 to the Free Software Foundation, 59 Temple Place - Suite 330, Cambridge, MA
20 02139, USA. */
23 * This file is a modified version of 'a.out.h'. It is to be used in all GNU
24 * tools modified to support the i80960 b.out format (or tools that operate on
25 * object files created by such tools).
27 * All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e.,
28 * object code is generated on, and executed under the direction of a symbolic
29 * debugger running on, a host system. We do not want to be subject to the
30 * vagaries of which host it is or whether it supports COFF or a.out format, or
31 * anything else. We DO want to:
33 * o always generate the same format object files, regardless of host.
35 * o have an 'a.out' header that we can modify for our own purposes
36 * (the 80960 is typically an embedded processor and may require
37 * enhanced linker support that the normal a.out.h header can't
38 * accommodate).
40 * As for byte-ordering, the following rules apply:
42 * o Text and data that is actually downloaded to the target is always
43 * in i80960 (little-endian) order.
45 * o All other numbers (in the header, symbols, relocation directives)
46 * are in host byte-order: object files CANNOT be lifted from a
47 * little-end host and used on a big-endian (or vice versa) without
48 * modification.
49 * ==> THIS IS NO LONGER TRUE USING BFD. WE CAN GENERATE ANY BYTE ORDER
50 * FOR THE HEADER, AND READ ANY BYTE ORDER. PREFERENCE WOULD BE TO
51 * USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST. <==
53 * o The downloader ('comm960') takes care to generate a pseudo-header
54 * with correct (i80960) byte-ordering before shipping text and data
55 * off to the NINDY monitor in the target systems. Symbols and
56 * relocation info are never sent to the target.
59 #define OBJ_BOUT 1
61 #define OUTPUT_FLAVOR bfd_target_aout_flavour
63 #include "targ-cpu.h"
65 #define OBJ_DEFAULT_OUTPUT_FILE_NAME "b.out"
67 extern const short seg_N_TYPE[];
68 extern const segT N_TYPE_seg[];
70 #define BMAGIC 0415
71 /* We don't accept the following (see N_BADMAG macro).
72 * They're just here so GNU code will compile.
74 #define OMAGIC 0407 /* old impure format */
75 #define NMAGIC 0410 /* read-only text */
76 #define ZMAGIC 0413 /* demand load format */
78 #ifndef DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE
79 #define DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE (BMAGIC)
80 #endif /* DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE */
82 /* FILE HEADER
83 * All 'lengths' are given as a number of bytes.
84 * All 'alignments' are for relinkable files only; an alignment of
85 * 'n' indicates the corresponding segment must begin at an
86 * address that is a multiple of (2**n).
88 struct exec
90 /* Standard stuff */
91 unsigned long a_magic; /* Identifies this as a b.out file */
92 unsigned long a_text; /* Length of text */
93 unsigned long a_data; /* Length of data */
94 unsigned long a_bss; /* Length of runtime uninitialized data area */
95 unsigned long a_syms; /* Length of symbol table */
96 unsigned long a_entry; /* Runtime start address */
97 unsigned long a_trsize; /* Length of text relocation info */
98 unsigned long a_drsize; /* Length of data relocation info */
100 /* Added for i960 */
101 unsigned long a_tload; /* Text runtime load address */
102 unsigned long a_dload; /* Data runtime load address */
103 unsigned char a_talign; /* Alignment of text segment */
104 unsigned char a_dalign; /* Alignment of data segment */
105 unsigned char a_balign; /* Alignment of bss segment */
106 unsigned char a_relaxable; /* Contains enough info to relax */
109 #define N_BADMAG(x) (((x).a_magic)!=BMAGIC)
110 #define N_TXTOFF(x) ( sizeof (struct exec) )
111 #define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text )
112 #define N_TROFF(x) ( N_DATOFF(x) + (x).a_data )
113 #define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize )
114 #define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize )
115 #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms )
117 /* A single entry in the symbol table
119 struct nlist
121 union
123 char *n_name;
124 struct nlist *n_next;
125 long n_strx; /* Index into string table */
127 n_un;
128 unsigned char n_type; /* See below */
129 char n_other; /* Used in i80960 support -- see below */
130 short n_desc;
131 unsigned long n_value;
134 typedef struct nlist obj_symbol_type;
136 /* Legal values of n_type
138 #define N_UNDF 0 /* Undefined symbol */
139 #define N_ABS 2 /* Absolute symbol */
140 #define N_TEXT 4 /* Text symbol */
141 #define N_DATA 6 /* Data symbol */
142 #define N_BSS 8 /* BSS symbol */
143 #define N_FN 31 /* Filename symbol */
145 #define N_EXT 1 /* External symbol (OR'd in with one of above) */
146 #define N_TYPE 036 /* Mask for all the type bits */
147 #define N_STAB 0340 /* Mask for all bits used for SDB entries */
149 #ifndef CUSTOM_RELOC_FORMAT
150 struct relocation_info
152 int r_address; /* File address of item to be relocated */
153 unsigned
154 r_index:24, /* Index of symbol on which relocation is based*/
155 r_pcrel:1, /* 1 => relocate PC-relative; else absolute
156 * On i960, pc-relative implies 24-bit
157 * address, absolute implies 32-bit.
159 r_length:2, /* Number of bytes to relocate:
160 * 0 => 1 byte
161 * 1 => 2 bytes
162 * 2 => 4 bytes -- only value used for i960
164 r_extern:1, r_bsr:1, /* Something for the GNU NS32K assembler */
165 r_disp:1, /* Something for the GNU NS32K assembler */
166 r_callj:1, /* 1 if relocation target is an i960 'callj' */
167 nuthin:1; /* Unused */
170 #endif /* CUSTOM_RELOC_FORMAT */
173 * Macros to extract information from a symbol table entry.
174 * This syntactic indirection allows independence regarding a.out or coff.
175 * The argument (s) of all these macros is a pointer to a symbol table entry.
178 /* Predicates */
179 /* True if the symbol is external */
180 #define S_IS_EXTERNAL(s) ((s)->sy_symbol.n_type & N_EXT)
182 /* True if symbol has been defined, ie is in N_{TEXT,DATA,BSS,ABS} or N_EXT */
183 #define S_IS_DEFINED(s) ((S_GET_TYPE(s) != N_UNDF) || (S_GET_DESC(s) != 0))
185 /* Return true for symbols that should not be reduced to section
186 symbols or eliminated from expressions, because they may be
187 overridden by the linker. */
188 #define S_FORCE_RELOC(s, strict) \
189 (!SEG_NORMAL (S_GET_SEGMENT (s)))
191 #define S_IS_COMMON(s) \
192 (S_GET_TYPE (s) == N_UNDF && S_GET_VALUE (s) != 0)
194 #define S_IS_REGISTER(s) ((s)->sy_symbol.n_type == N_REGISTER)
196 /* True if a debug special symbol entry */
197 #define S_IS_DEBUG(s) ((s)->sy_symbol.n_type & N_STAB)
198 /* True if a symbol is local symbol name */
199 #define S_IS_LOCAL(s) \
200 ((S_GET_NAME (s) \
201 && !S_IS_DEBUG (s) \
202 && (strchr (S_GET_NAME (s), '\001') != NULL \
203 || strchr (S_GET_NAME (s), '\002') != NULL \
204 || (S_LOCAL_NAME(s) && !flag_keep_locals))) \
205 || (flag_strip_local_absolute \
206 && !S_IS_EXTERNAL(s) \
207 && S_GET_SEGMENT(s) == absolute_section))
208 /* True if a symbol is not defined in this file */
209 #define S_IS_EXTERN(s) ((s)->sy_symbol.n_type & N_EXT)
210 /* True if the symbol has been generated because of a .stabd directive */
211 #define S_IS_STABD(s) (S_GET_NAME(s) == NULL)
213 /* Accessors */
214 /* The name of the symbol */
215 #define S_GET_NAME(s) ((s)->sy_symbol.n_un.n_name)
216 /* The pointer to the string table */
217 #define S_GET_OFFSET(s) ((s)->sy_symbol.n_un.n_strx)
218 /* The type of the symbol */
219 #define S_GET_TYPE(s) ((s)->sy_symbol.n_type & N_TYPE)
220 /* The numeric value of the segment */
221 #define S_GET_SEGMENT(s) (N_TYPE_seg[S_GET_TYPE(s)])
222 /* The n_other expression value */
223 #define S_GET_OTHER(s) ((s)->sy_symbol.n_other)
224 /* The n_desc expression value */
225 #define S_GET_DESC(s) ((s)->sy_symbol.n_desc)
227 /* Modifiers */
228 /* Assume that a symbol cannot be simultaneously in more than on segment */
229 /* set segment */
230 #define S_SET_SEGMENT(s,seg) ((s)->sy_symbol.n_type &= ~N_TYPE,(s)->sy_symbol.n_type|=SEGMENT_TO_SYMBOL_TYPE(seg))
231 /* The symbol is external */
232 #define S_SET_EXTERNAL(s) ((s)->sy_symbol.n_type |= N_EXT)
233 /* The symbol is not external */
234 #define S_CLEAR_EXTERNAL(s) ((s)->sy_symbol.n_type &= ~N_EXT)
235 /* Set the name of the symbol */
236 #define S_SET_NAME(s,v) ((s)->sy_symbol.n_un.n_name = (v))
237 /* Set the offset in the string table */
238 #define S_SET_OFFSET(s,v) ((s)->sy_symbol.n_un.n_strx = (v))
239 /* Set the n_other expression value */
240 #define S_SET_OTHER(s,v) ((s)->sy_symbol.n_other = (v))
241 /* Set the n_desc expression value */
242 #define S_SET_DESC(s,v) ((s)->sy_symbol.n_desc = (v))
243 /* Set the n_type value */
244 #define S_SET_TYPE(s,v) ((s)->sy_symbol.n_type = (v))
246 /* File header macro and type definition */
248 #define H_GET_FILE_SIZE(h) (sizeof (struct exec) + \
249 H_GET_TEXT_SIZE(h) + H_GET_DATA_SIZE(h) + \
250 H_GET_SYMBOL_TABLE_SIZE(h) + \
251 H_GET_TEXT_RELOCATION_SIZE(h) + \
252 H_GET_DATA_RELOCATION_SIZE(h) + \
253 (h)->string_table_size)
255 #define H_GET_HEADER_SIZE(h) (sizeof (struct exec))
256 #define H_GET_TEXT_SIZE(h) ((h)->header.a_text)
257 #define H_GET_DATA_SIZE(h) ((h)->header.a_data)
258 #define H_GET_BSS_SIZE(h) ((h)->header.a_bss)
259 #define H_GET_TEXT_RELOCATION_SIZE(h) ((h)->header.a_trsize)
260 #define H_GET_DATA_RELOCATION_SIZE(h) ((h)->header.a_drsize)
261 #define H_GET_SYMBOL_TABLE_SIZE(h) ((h)->header.a_syms)
262 #define H_GET_MAGIC_NUMBER(h) ((h)->header.a_info)
263 #define H_GET_ENTRY_POINT(h) ((h)->header.a_entry)
264 #define H_GET_STRING_SIZE(h) ((h)->string_table_size)
265 #define H_GET_LINENO_SIZE(h) (0)
267 #ifdef EXEC_MACHINE_TYPE
268 #define H_GET_MACHINE_TYPE(h) ((h)->header.a_machtype)
269 #endif /* EXEC_MACHINE_TYPE */
270 #ifdef EXEC_VERSION
271 #define H_GET_VERSION(h) ((h)->header.a_version)
272 #endif /* EXEC_VERSION */
274 #define H_SET_TEXT_SIZE(h,v) ((h)->header.a_text = (v))
275 #define H_SET_DATA_SIZE(h,v) ((h)->header.a_data = (v))
276 #define H_SET_BSS_SIZE(h,v) ((h)->header.a_bss = (v))
278 #define H_SET_RELOCATION_SIZE(h,t,d) (H_SET_TEXT_RELOCATION_SIZE((h),(t)),\
279 H_SET_DATA_RELOCATION_SIZE((h),(d)))
281 #define H_SET_TEXT_RELOCATION_SIZE(h,v) ((h)->header.a_trsize = (v))
282 #define H_SET_DATA_RELOCATION_SIZE(h,v) ((h)->header.a_drsize = (v))
283 #define H_SET_SYMBOL_TABLE_SIZE(h,v) ((h)->header.a_syms = (v) * \
284 sizeof (struct nlist))
286 #define H_SET_MAGIC_NUMBER(h,v) ((h)->header.a_magic = (v))
288 #define H_SET_ENTRY_POINT(h,v) ((h)->header.a_entry = (v))
289 #define H_SET_STRING_SIZE(h,v) ((h)->string_table_size = (v))
290 #ifdef EXEC_MACHINE_TYPE
291 #define H_SET_MACHINE_TYPE(h,v) ((h)->header.a_machtype = (v))
292 #endif /* EXEC_MACHINE_TYPE */
293 #ifdef EXEC_VERSION
294 #define H_SET_VERSION(h,v) ((h)->header.a_version = (v))
295 #endif /* EXEC_VERSION */
297 typedef struct
299 struct exec header; /* a.out header */
300 long string_table_size; /* names + '\0' + sizeof (int) */
303 object_headers;
305 /* unused hooks. */
306 #define OBJ_EMIT_LINENO(a, b, c) {;}
307 #define obj_pre_write_hook(a) {;}
309 #if __STDC__
310 struct fix;
311 #endif
312 extern void tc_aout_fix_to_chars PARAMS ((char *where,
313 struct fix *fixP,
314 relax_addressT segment_address));
315 extern void tc_bout_fix_to_chars PARAMS ((char *where,
316 struct fix *fixP,
317 relax_addressT segment_address));
319 #define AOUT_STABS