1 /* This file is aout_gnu.h
2 
3    Copyright 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 2000, 2002
4    Free Software Foundation, Inc.
5 
6    This file is part of GAS, the GNU Assembler.
7 
8    GAS is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 2, or (at your option)
11    any later version.
12 
13    GAS is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with GAS; see the file COPYING.  If not, write to
20    the Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
21 
22 #ifndef __A_OUT_GNU_H__
23 #define __A_OUT_GNU_H__
24 
25 /* There are two main flavours of a.out, one which uses the standard
26    relocations, and one which uses extended relocations.
27 
28    Today, the extended reloc uses are
29    TC_SPARC
30 
31    each must define the enum reloc_type
32 
33 */
34 
35 #define USE_EXTENDED_RELOC defined(TC_SPARC)
36 
37 #if defined(TC_SPARC)
38 enum reloc_type
39   {
40     RELOC_8, RELOC_16, RELOC_32,/* simple relocations */
41     RELOC_DISP8, RELOC_DISP16, RELOC_DISP32,	/* pc-rel displacement */
42     RELOC_WDISP30, RELOC_WDISP22,
43     RELOC_HI22, RELOC_22,
44     RELOC_13, RELOC_LO10,
45     RELOC_SFA_BASE, RELOC_SFA_OFF13,
46     RELOC_BASE10, RELOC_BASE13, RELOC_BASE22,	/* P.I.C. (base-relative) */
47     RELOC_PC10, RELOC_PC22,	/* for some sort of pc-rel P.I.C. (?) */
48     RELOC_JMP_TBL,		/* P.I.C. jump table */
49     RELOC_SEGOFF16,		/* reputedly for shared libraries somehow */
50     RELOC_GLOB_DAT, RELOC_JMP_SLOT, RELOC_RELATIVE,
51     RELOC_10, RELOC_11,
52     RELOC_WDISP2_14,
53     RELOC_WDISP19,
54     RELOC_HHI22,
55     RELOC_HLO10,
56 
57     /* 29K relocation types */
58     RELOC_JUMPTARG, RELOC_CONST, RELOC_CONSTH,
59 
60     RELOC_WDISP14, RELOC_WDISP21,
61 
62     NO_RELOC
63   };
64 
65 #endif /* TC_SPARC */
66 
67 #define __GNU_EXEC_MACROS__
68 
69 #ifndef __STRUCT_EXEC_OVERRIDE__
70 
71 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
72    "struct exec".  Don't assume that on this machine, the "struct exec"
73    will lay out the same sizes or alignments.  */
74 
75 struct exec_bytes
76   {
77     unsigned char a_info[4];
78     unsigned char a_text[4];
79     unsigned char a_data[4];
80     unsigned char a_bss[4];
81     unsigned char a_syms[4];
82     unsigned char a_entry[4];
83     unsigned char a_trsize[4];
84     unsigned char a_drsize[4];
85   };
86 
87 /* How big the "struct exec" is on disk */
88 #define	EXEC_BYTES_SIZE	(8 * 4)
89 
90 /* This is the layout in memory of a "struct exec" while we process it.  */
91 
92 struct exec
93 {
94   unsigned long a_info;		/* Use macros N_MAGIC, etc for access */
95   unsigned a_text;		/* length of text, in bytes */
96   unsigned a_data;		/* length of data, in bytes */
97   unsigned a_bss;		/* length of uninitialized data area for file, in bytes */
98   unsigned a_syms;		/* length of symbol table data in file, in bytes */
99   unsigned a_entry;		/* start address */
100   unsigned a_trsize;		/* length of relocation info for text, in bytes */
101   unsigned a_drsize;		/* length of relocation info for data, in bytes */
102 };
103 
104 #endif /* __STRUCT_EXEC_OVERRIDE__ */
105 
106 /* these go in the N_MACHTYPE field */
107 /* These symbols could be defined by code from Suns...punt 'em */
108 #undef M_UNKNOWN
109 #undef M_68010
110 #undef M_68020
111 #undef M_SPARC
112 enum machine_type
113   {
114     M_UNKNOWN = 0,
115     M_68010 = 1,
116     M_68020 = 2,
117     M_SPARC = 3,
118     /* skip a bunch so we don't run into any of sun's numbers */
119     M_386 = 100,
120     M_29K = 101,
121     M_RS6000 = 102,		/* IBM RS/6000 */
122     M_VAX4K_NETBSD = 150,
123     M_88K_OPENBSD = 153,
124     /* HP/BSD formats */
125     M_HP200 = 200,		/* hp200 (68010) BSD binary */
126     M_HP300 = 300,		/* hp300 (68020+68881) BSD binary */
127     M_HPUX23 = 0x020C		/* hp200/300 HPUX binary */
128   };
129 
130 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
131 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
132 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
133 #define N_SET_INFO(exec, magic, type, flags) \
134     ((exec).a_info = ((magic) & 0xffff) \
135      | (((int)(type) & 0xff) << 16) \
136      | (((flags) & 0xff) << 24))
137 #define N_SET_MAGIC(exec, magic) \
138     ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
139 
140 #define N_SET_MACHTYPE(exec, machtype) \
141     ((exec).a_info = \
142      ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
143 
144 #define N_SET_FLAGS(exec, flags) \
145     ((exec).a_info = \
146      ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
147 
148 /* Code indicating object file or impure executable.  */
149 #ifndef OMAGIC
150 #define OMAGIC 0407
151 #endif
152 /* Code indicating pure executable.  */
153 #define NMAGIC 0410
154 /* Code indicating demand-paged executable.  */
155 #define ZMAGIC 0413
156 
157 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
158    (almost always "unlinked .o's" these days), should be zero.
159    For linked files, should reflect reality if we know it.  */
160 
161 #ifndef N_TXTADDR
162 #define N_TXTADDR(x)	(N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
163 #endif
164 
165 #ifndef N_BADMAG
166 #define N_BADMAG(x)	  (N_MAGIC(x) != OMAGIC		\
167 			   && N_MAGIC(x) != NMAGIC		\
168 			   && N_MAGIC(x) != ZMAGIC)
169 #endif
170 
171 /* By default, segment size is constant.  But on some machines, it can
172    be a function of the a.out header (e.g. machine type).  */
173 #ifndef	N_SEGSIZE
174 #define	N_SEGSIZE(x)	SEGMENT_SIZE
175 #endif
176 
177 /* This complexity is for encapsulated COFF support */
178 #ifndef _N_HDROFF
179 #define _N_HDROFF(x)	(N_SEGSIZE(x) - sizeof (struct exec))
180 #endif
181 
182 #ifndef N_TXTOFF
183 #define N_TXTOFF(x)	(N_MAGIC(x) == ZMAGIC ?	\
184 			 _N_HDROFF((x)) + sizeof (struct exec) :	\
185 			 sizeof (struct exec))
186 #endif
187 
188 #ifndef N_DATOFF
189 #define N_DATOFF(x)	( N_TXTOFF(x) + (x).a_text )
190 #endif
191 
192 #ifndef N_TRELOFF
193 #define N_TRELOFF(x)	( N_DATOFF(x) + (x).a_data )
194 #endif
195 
196 #ifndef N_DRELOFF
197 #define N_DRELOFF(x)	( N_TRELOFF(x) + (x).a_trsize )
198 #endif
199 
200 #ifndef N_SYMOFF
201 #define N_SYMOFF(x)	( N_DRELOFF(x) + (x).a_drsize )
202 #endif
203 
204 #ifndef N_STROFF
205 #define N_STROFF(x)	( N_SYMOFF(x) + (x).a_syms )
206 #endif
207 
208 /* Address of text segment in memory after it is loaded.  */
209 #ifndef N_TXTADDR
210 #define	N_TXTADDR(x)	0
211 #endif
212 
213 #ifndef N_DATADDR
214 #define N_DATADDR(x) \
215     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
216      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x).a_text-1) & ~(N_SEGSIZE(x)-1))))
217 #endif
218 
219 /* Address of bss segment in memory after it is loaded.  */
220 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
221 
222 struct nlist
223   {
224     union
225       {
226 	char *n_name;
227 	struct nlist *n_next;
228 	long n_strx;
229       }
230     n_un;
231     unsigned char n_type;
232     char n_other;
233     short n_desc;
234     unsigned long n_value;
235   };
236 
237 #define N_UNDF 0
238 #define N_ABS 2
239 #define N_TEXT 4
240 #define N_DATA 6
241 #define N_BSS 8
242 #define	N_COMM	0x12		/* common (visible in shared lib commons) */
243 #define N_FN 0x1F		/* File name of a .o file */
244 
245 /* Note: N_EXT can only usefully be OR-ed with N_UNDF, N_ABS, N_TEXT,
246    N_DATA, or N_BSS.  When the low-order bit of other types is set,
247    (e.g. N_WARNING versus N_FN), they are two different types.  */
248 #define N_EXT 1
249 #define N_TYPE 036
250 #define N_STAB 0340
251 
252 /* The following type indicates the definition of a symbol as being
253    an indirect reference to another symbol.  The other symbol
254    appears as an undefined reference, immediately following this symbol.
255 
256    Indirection is asymmetrical.  The other symbol's value will be used
257    to satisfy requests for the indirect symbol, but not vice versa.
258    If the other symbol does not have a definition, libraries will
259    be searched to find a definition.  */
260 
261 #define N_INDR 0xa
262 
263 /* The following symbols refer to set elements.
264    All the N_SET[ATDB] symbols with the same name form one set.
265    Space is allocated for the set in the text section, and each set
266    element's value is stored into one word of the space.
267    The first word of the space is the length of the set (number of elements).
268 
269    The address of the set is made into an N_SETV symbol
270    whose name is the same as the name of the set.
271    This symbol acts like a N_DATA global symbol
272    in that it can satisfy undefined external references.  */
273 
274 /* These appear as input to LD, in a .o file.  */
275 #define	N_SETA	0x14		/* Absolute set element symbol */
276 #define	N_SETT	0x16		/* Text set element symbol */
277 #define	N_SETD	0x18		/* Data set element symbol */
278 #define	N_SETB	0x1A		/* Bss set element symbol */
279 
280 /* This is output from LD.  */
281 #define N_SETV	0x1C		/* Pointer to set vector in data area.  */
282 
283 /* Warning symbol. The text gives a warning message, the next symbol
284    in the table will be undefined. When the symbol is referenced, the
285    message is printed.  */
286 
287 #define	N_WARNING 0x1e
288 
289 /* Weak symbols.  These are a GNU extension to the a.out format.  The
290    semantics are those of ELF weak symbols.  Weak symbols are always
291    externally visible.  The N_WEAK? values are squeezed into the
292    available slots.  The value of a N_WEAKU symbol is 0.  The values
293    of the other types are the definitions.  */
294 #define N_WEAKU	0x0d		/* Weak undefined symbol.  */
295 #define N_WEAKA 0x0e		/* Weak absolute symbol.  */
296 #define N_WEAKT 0x0f		/* Weak text symbol.  */
297 #define N_WEAKD 0x10		/* Weak data symbol.  */
298 #define N_WEAKB 0x11		/* Weak bss symbol.  */
299 
300 /* This structure describes a single relocation to be performed.
301    The text-relocation section of the file is a vector of these structures,
302    all of which apply to the text section.
303    Likewise, the data-relocation section applies to the data section.  */
304 
305 /* The following enum and struct were borrowed from SunOS's
306    /usr/include/sun4/a.out.h  and extended to handle
307    other machines.  It is currently used on SPARC and AMD 29000.
308 
309    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
310    how we might process it on a native host.  */
311 #if USE_EXTENDED_RELOC
312 
313 struct reloc_ext_bytes
314   {
315     unsigned char r_address[4];
316     unsigned char r_index[3];
317     unsigned char r_bits[1];
318     unsigned char r_addend[4];
319   };
320 
321 #define	RELOC_EXT_BITS_EXTERN_BIG	0x80
322 #define	RELOC_EXT_BITS_EXTERN_LITTLE	0x01
323 
324 #define	RELOC_EXT_BITS_TYPE_BIG		0x1F
325 #define	RELOC_EXT_BITS_TYPE_SH_BIG	0
326 #define	RELOC_EXT_BITS_TYPE_LITTLE	0xF8
327 #define	RELOC_EXT_BITS_TYPE_SH_LITTLE	3
328 
329 #define	RELOC_EXT_SIZE	12	/* Bytes per relocation entry */
330 
331 struct reloc_info_extended
332 {
333   unsigned long r_address;
334   unsigned int r_index:24;
335 # define	r_symbolnum  r_index
336   unsigned r_extern:1;
337   unsigned:2;
338   /*  RS/6000 compiler does not support enum bitfield
339 	    enum reloc_type r_type:5; */
340   enum reloc_type r_type;
341   long int r_addend;
342 };
343 
344 #else
345 
346 /* The standard, old-fashioned, Berkeley compatible relocation struct */
347 
348 #ifdef TC_I860
349 /* NOTE: three bits max, see struct reloc_info_i860.r_type */
350 enum i860_reloc_type
351   {
352     NO_RELOC = 0, BRADDR, LOW0, LOW1, LOW2, LOW3, LOW4, SPLIT0, SPLIT1, SPLIT2, RELOC_32,
353   };
354 
355 typedef enum i860_reloc_type reloc_type;
356 
357 /* NOTE: two bits max, see reloc_info_i860.r_type */
358 enum highlow_type
359   {
360     NO_SPEC = 0, PAIR, HIGH, HIGHADJ,
361   };
362 
363 struct reloc_info_i860
364 {
365   unsigned long r_address;
366   /*
367 	 * Using bit fields here is a bad idea because the order is not portable. :-(
368 	 */
369   unsigned int r_symbolnum:24;
370   unsigned int r_pcrel:1;
371   unsigned int r_extern:1;
372   /* combining the two field simplifies the argument passing in "new_fix()" */
373   /* and is compatible with the existing Sparc #ifdef's */
374   /* r_type:  highlow_type - bits 5,4; reloc_type - bits 3-0 */
375   unsigned int r_type:6;
376   long r_addend;
377 };
378 
379 #endif /* TC_I860 */
380 
381 struct reloc_std_bytes
382   {
383     unsigned char r_address[4];
384     unsigned char r_index[3];
385     unsigned char r_bits[1];
386   };
387 
388 #define	RELOC_STD_BITS_PCREL_BIG	0x80
389 #define	RELOC_STD_BITS_PCREL_LITTLE	0x01
390 
391 #define	RELOC_STD_BITS_LENGTH_BIG	0x60
392 #define	RELOC_STD_BITS_LENGTH_SH_BIG	5	/* To shift to units place */
393 #define	RELOC_STD_BITS_LENGTH_LITTLE	0x06
394 #define	RELOC_STD_BITS_LENGTH_SH_LITTLE	1
395 
396 #define	RELOC_STD_BITS_EXTERN_BIG	0x10
397 #define	RELOC_STD_BITS_EXTERN_LITTLE	0x08
398 
399 #define	RELOC_STD_BITS_BASEREL_BIG	0x08
400 #define	RELOC_STD_BITS_BASEREL_LITTLE	0x08
401 
402 #define	RELOC_STD_BITS_JMPTABLE_BIG	0x04
403 #define	RELOC_STD_BITS_JMPTABLE_LITTLE	0x04
404 
405 #define	RELOC_STD_BITS_RELATIVE_BIG	0x02
406 #define	RELOC_STD_BITS_RELATIVE_LITTLE	0x02
407 
408 #define	RELOC_STD_SIZE	8	/* Bytes per relocation entry */
409 
410 #endif /* USE_EXTENDED_RELOC */
411 
412 #ifndef CUSTOM_RELOC_FORMAT
413 struct relocation_info
414 {
415   /* Address (within segment) to be relocated.  */
416   int r_address;
417   /* The meaning of r_symbolnum depends on r_extern.  */
418   unsigned int r_symbolnum:24;
419   /* Nonzero means value is a pc-relative offset
420 	   and it should be relocated for changes in its own address
421 	   as well as for changes in the symbol or section specified.  */
422   unsigned int r_pcrel:1;
423   /* Length (as exponent of 2) of the field to be relocated.
424 	   Thus, a value of 2 indicates 1<<2 bytes.  */
425   unsigned int r_length:2;
426   /* 1 => relocate with value of symbol.
427 	   r_symbolnum is the index of the symbol
428 	   in file's the symbol table.
429 	   0 => relocate with the address of a segment.
430 	   r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
431 	   (the N_EXT bit may be set also, but signifies nothing).  */
432   unsigned int r_extern:1;
433   /* The next three bits are for SunOS shared libraries, and seem to
434 	   be undocumented.  */
435 #ifdef TC_NS32K
436   unsigned int r_bsr:1;
437   unsigned int r_disp:2;
438 #else
439   unsigned int r_baserel:1;	/* Linkage table relative */
440   unsigned int r_jmptable:1;	/* pc-relative to jump table */
441   unsigned int r_relative:1;	/* "relative relocation" */
442 #endif /* TC_NS32K */
443   /* unused */
444   unsigned int r_pad:1;		/* Padding -- set to zero */
445 };
446 
447 #endif /* CUSTOM_RELOC_FORMAT */
448 
449 #endif /* __A_OUT_GNU_H__ */
450 
451 /* end of aout_gnu.h */
452