1 /* This file is a.out.gnu.h
3 Copyright (C) 1987-1992 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 published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GAS is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GAS; see the file COPYING. If not, write to
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 #ifndef __A_OUT_GNU_H__
22 #define __A_OUT_GNU_H__
24 #include "aout/reloc.h"
26 #define __GNU_EXEC_MACROS__
28 #ifndef __STRUCT_EXEC_OVERRIDE__
30 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
31 "struct exec". Don't assume that on this machine, the "struct exec"
32 will lay out the same sizes or alignments. */
35 unsigned char a_info
[4];
36 unsigned char a_text
[4];
37 unsigned char a_data
[4];
38 unsigned char a_bss
[4];
39 unsigned char a_syms
[4];
40 unsigned char a_entry
[4];
41 unsigned char a_trsize
[4];
42 unsigned char a_drsize
[4];
45 /* How big the "struct exec" is on disk */
46 #define EXEC_BYTES_SIZE (8 * 4)
48 /* This is the layout in memory of a "struct exec" while we process it. */
52 unsigned long a_info
; /* Use macros N_MAGIC, etc for access */
53 unsigned a_text
; /* length of text, in bytes */
54 unsigned a_data
; /* length of data, in bytes */
55 unsigned a_bss
; /* length of uninitialized data area for file, in bytes */
56 unsigned a_syms
; /* length of symbol table data in file, in bytes */
57 unsigned a_entry
; /* start address */
58 unsigned a_trsize
; /* length of relocation info for text, in bytes */
59 unsigned a_drsize
; /* length of relocation info for data, in bytes */
62 #endif /* __STRUCT_EXEC_OVERRIDE__ */
64 /* these go in the N_MACHTYPE field */
65 /* These symbols could be defined by code from Suns...punt 'em */
75 /* skip a bunch so we don't run into any of sun's numbers */
78 M_RS6000
= 102, /* IBM RS/6000 */
80 M_HP200
= 200, /* hp200 (68010) BSD binary */
81 M_HP300
= 300, /* hp300 (68020+68881) BSD binary */
82 M_HPUX23
= 0x020C, /* hp200/300 HPUX binary */
85 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
86 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
87 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
88 #define N_SET_INFO(exec, magic, type, flags) \
89 ((exec).a_info = ((magic) & 0xffff) \
90 | (((int)(type) & 0xff) << 16) \
91 | (((flags) & 0xff) << 24))
92 #define N_SET_MAGIC(exec, magic) \
93 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
95 #define N_SET_MACHTYPE(exec, machtype) \
97 ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
99 #define N_SET_FLAGS(exec, flags) \
101 ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
103 /* Code indicating object file or impure executable. */
105 /* Code indicating pure executable. */
107 /* Code indicating demand-paged executable. */
110 /* Virtual Address of text segment from the a.out file. For OMAGIC,
111 (almost always "unlinked .o's" these days), should be zero.
112 For linked files, should reflect reality if we know it. */
115 #define N_TXTADDR(x) (N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
119 #define N_BADMAG(x) (N_MAGIC(x) != OMAGIC \
120 && N_MAGIC(x) != NMAGIC \
121 && N_MAGIC(x) != ZMAGIC)
124 /* By default, segment size is constant. But on some machines, it can
125 be a function of the a.out header (e.g. machine type). */
127 #define N_SEGSIZE(x) SEGMENT_SIZE
130 /* This complexity is for encapsulated COFF support */
132 #define _N_HDROFF(x) (N_SEGSIZE(x) - sizeof (struct exec))
136 #define N_TXTOFF(x) (N_MAGIC(x) == ZMAGIC ? \
137 _N_HDROFF((x)) + sizeof (struct exec) : \
138 sizeof (struct exec))
143 #define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text )
147 #define N_TRELOFF(x) ( N_DATOFF(x) + (x).a_data )
151 #define N_DRELOFF(x) ( N_TRELOFF(x) + (x).a_trsize )
155 #define N_SYMOFF(x) ( N_DRELOFF(x) + (x).a_drsize )
159 #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms )
162 /* Address of text segment in memory after it is loaded. */
164 #define N_TXTADDR(x) 0
168 #define N_DATADDR(x) \
169 (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
170 : (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x).a_text-1) & ~(N_SEGSIZE(x)-1))))
173 /* Address of bss segment in memory after it is loaded. */
174 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
179 struct nlist
*n_next
;
182 unsigned char n_type
;
185 unsigned long n_value
;
193 #define N_COMM 0x12 /* common (visible in shared lib commons) */
194 #define N_FN 0x1F /* File name of a .o file */
196 /* Note: N_EXT can only usefully be OR-ed with N_UNDF, N_ABS, N_TEXT,
197 N_DATA, or N_BSS. When the low-order bit of other types is set,
198 (e.g. N_WARNING versus N_FN), they are two different types. */
203 /* The following type indicates the definition of a symbol as being
204 an indirect reference to another symbol. The other symbol
205 appears as an undefined reference, immediately following this symbol.
207 Indirection is asymmetrical. The other symbol's value will be used
208 to satisfy requests for the indirect symbol, but not vice versa.
209 If the other symbol does not have a definition, libraries will
210 be searched to find a definition. */
214 /* The following symbols refer to set elements.
215 All the N_SET[ATDB] symbols with the same name form one set.
216 Space is allocated for the set in the text section, and each set
217 element's value is stored into one word of the space.
218 The first word of the space is the length of the set (number of elements).
220 The address of the set is made into an N_SETV symbol
221 whose name is the same as the name of the set.
222 This symbol acts like a N_DATA global symbol
223 in that it can satisfy undefined external references. */
225 /* These appear as input to LD, in a .o file. */
226 #define N_SETA 0x14 /* Absolute set element symbol */
227 #define N_SETT 0x16 /* Text set element symbol */
228 #define N_SETD 0x18 /* Data set element symbol */
229 #define N_SETB 0x1A /* Bss set element symbol */
231 /* This is output from LD. */
232 #define N_SETV 0x1C /* Pointer to set vector in data area. */
234 /* Warning symbol. The text gives a warning message, the next symbol
235 in the table will be undefined. When the symbol is referenced, the
236 message is printed. */
238 #define N_WARNING 0x1e
240 /* This structure describes a single relocation to be performed.
241 The text-relocation section of the file is a vector of these structures,
242 all of which apply to the text section.
243 Likewise, the data-relocation section applies to the data section. */
245 /* The following enum and struct were borrowed from SunOS's
246 /usr/include/sun4/a.out.h and extended to handle
247 other machines. It is currently used on SPARC and AMD 29000.
249 reloc_ext_bytes is how it looks on disk. reloc_info_extended is
250 how we might process it on a native host. */
252 struct reloc_ext_bytes
{
253 unsigned char r_address
[4];
254 unsigned char r_index
[3];
255 unsigned char r_bits
[1];
256 unsigned char r_addend
[4];
259 #define RELOC_EXT_BITS_EXTERN_BIG 0x80
260 #define RELOC_EXT_BITS_EXTERN_LITTLE 0x01
262 #define RELOC_EXT_BITS_TYPE_BIG 0x1F
263 #define RELOC_EXT_BITS_TYPE_SH_BIG 0
264 #define RELOC_EXT_BITS_TYPE_LITTLE 0xF8
265 #define RELOC_EXT_BITS_TYPE_SH_LITTLE 3
267 #define RELOC_EXT_SIZE 12 /* Bytes per relocation entry */
269 struct reloc_info_extended
271 unsigned long r_address
;
272 unsigned int r_index
:24;
273 # define r_symbolnum r_index
276 /* RS/6000 compiler does not support enum bitfield
277 enum reloc_type r_type:5; */
278 enum reloc_type r_type
;
282 /* The standard, old-fashioned, Berkeley compatible relocation struct */
284 struct reloc_std_bytes
{
285 unsigned char r_address
[4];
286 unsigned char r_index
[3];
287 unsigned char r_bits
[1];
290 #define RELOC_STD_BITS_PCREL_BIG 0x80
291 #define RELOC_STD_BITS_PCREL_LITTLE 0x01
293 #define RELOC_STD_BITS_LENGTH_BIG 0x60
294 #define RELOC_STD_BITS_LENGTH_SH_BIG 5 /* To shift to units place */
295 #define RELOC_STD_BITS_LENGTH_LITTLE 0x06
296 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
298 #define RELOC_STD_BITS_EXTERN_BIG 0x10
299 #define RELOC_STD_BITS_EXTERN_LITTLE 0x08
301 #define RELOC_STD_BITS_BASEREL_BIG 0x08
302 #define RELOC_STD_BITS_BASEREL_LITTLE 0x08
304 #define RELOC_STD_BITS_JMPTABLE_BIG 0x04
305 #define RELOC_STD_BITS_JMPTABLE_LITTLE 0x04
307 #define RELOC_STD_BITS_RELATIVE_BIG 0x02
308 #define RELOC_STD_BITS_RELATIVE_LITTLE 0x02
310 #define RELOC_STD_SIZE 8 /* Bytes per relocation entry */
312 #ifndef CUSTOM_RELOC_FORMAT
313 struct relocation_info
315 /* Address (within segment) to be relocated. */
317 /* The meaning of r_symbolnum depends on r_extern. */
318 unsigned int r_symbolnum
:24;
319 /* Nonzero means value is a pc-relative offset
320 and it should be relocated for changes in its own address
321 as well as for changes in the symbol or section specified. */
322 unsigned int r_pcrel
:1;
323 /* Length (as exponent of 2) of the field to be relocated.
324 Thus, a value of 2 indicates 1<<2 bytes. */
325 unsigned int r_length
:2;
326 /* 1 => relocate with value of symbol.
327 r_symbolnum is the index of the symbol
328 in file's the symbol table.
329 0 => relocate with the address of a segment.
330 r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
331 (the N_EXT bit may be set also, but signifies nothing). */
332 unsigned int r_extern
:1;
333 /* The next three bits are for SunOS shared libraries, and seem to
335 unsigned int r_baserel
:1; /* Linkage table relative */
336 unsigned int r_jmptable
:1; /* pc-relative to jump table */
339 #define r_bsr r_baserel
340 #define r_disp r_jmptable
341 #endif /* TC_NS32K */
343 unsigned int r_relative
:1; /* "relative relocation" */
345 unsigned int r_pad
:1; /* Padding -- set to zero */
347 #endif /* CUSTOM_RELOC_FORMAT */
349 #endif /* __A_OUT_GNU_H__ */
351 /* end of a.out.gnu.h */
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