1 #ifndef __A_OUT_GNU_H__
2 #define __A_OUT_GNU_H__
6 #define __GNU_EXEC_MACROS__
8 #ifndef __STRUCT_EXEC_OVERRIDE__
10 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
11 "struct exec". Don't assume that on this machine, the "struct exec"
12 will lay out the same sizes or alignments. */
15 unsigned char a_info[4];
16 unsigned char a_text[4];
17 unsigned char a_data[4];
18 unsigned char a_bss[4];
19 unsigned char a_syms[4];
20 unsigned char a_entry[4];
21 unsigned char a_trsize[4];
22 unsigned char a_drsize[4];
25 /* How big the "struct exec" is on disk */
26 #define EXEC_BYTES_SIZE (8 * 4)
28 /* This is the layout in memory of a "struct exec" while we process it. */
32 unsigned long a_info; /* Use macros N_MAGIC, etc for access */
33 unsigned a_text; /* length of text, in bytes */
34 unsigned a_data; /* length of data, in bytes */
35 unsigned a_bss; /* length of uninitialized data area for file, in bytes */
36 unsigned a_syms; /* length of symbol table data in file, in bytes */
37 unsigned a_entry; /* start address */
38 unsigned a_trsize; /* length of relocation info for text, in bytes */
39 unsigned a_drsize; /* length of relocation info for data, in bytes */
42 #endif /* __STRUCT_EXEC_OVERRIDE__ */
44 /* these go in the N_MACHTYPE field */
45 /* These symbols could be defined by code from Suns...punt 'em */
55 /* skip a bunch so we don't run into any of sun's numbers */
60 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
61 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
62 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
63 #define N_SET_INFO(exec, magic, type, flags) \
64 ((exec).a_info = ((magic) & 0xffff) \
65 | (((int)(type) & 0xff) << 16) \
66 | (((flags) & 0xff) << 24))
67 #define N_SET_MAGIC(exec, magic) \
68 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
70 #define N_SET_MACHTYPE(exec, machtype) \
72 ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
74 #define N_SET_FLAGS(exec, flags) \
76 ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
78 /* Code indicating object file or impure executable. */
80 /* Code indicating pure executable. */
82 /* Code indicating demand-paged executable. */
85 /* Virtual Address of text segment from the a.out file. For OMAGIC,
86 (almost always "unlinked .o's" these days), should be zero.
87 For linked files, should reflect reality if we know it. */
90 #define N_TXTADDR(x) (N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
94 #define N_BADMAG(x) (N_MAGIC(x) != OMAGIC \
95 && N_MAGIC(x) != NMAGIC \
96 && N_MAGIC(x) != ZMAGIC)
99 /* This complexity is for encapsulated COFF support */
101 #define _N_HDROFF(x) (SEGMENT_SIZE - sizeof (struct exec))
105 #define N_TXTOFF(x) (N_MAGIC(x) == ZMAGIC ? \
106 _N_HDROFF((x)) + sizeof (struct exec) : \
107 sizeof (struct exec))
112 #define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text )
116 #define N_TRELOFF(x) ( N_DATOFF(x) + (x).a_data )
120 #define N_DRELOFF(x) ( N_TRELOFF(x) + (x).a_trsize )
124 #define N_SYMOFF(x) ( N_DRELOFF(x) + (x).a_drsize )
128 #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms )
131 /* Address of text segment in memory after it is loaded. */
133 #define N_TXTADDR(x) 0
137 #define N_DATADDR(x) \
138 (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x).a_text) \
139 : (SEGMENT_SIZE + ((N_TXTADDR(x)+(x).a_text-1) & ~(SEGMENT_SIZE-1))))
142 /* Address of bss segment in memory after it is loaded. */
143 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
148 struct nlist *n_next;
151 unsigned char n_type;
154 unsigned long n_value;
168 /* The following type indicates the definition of a symbol as being
169 an indirect reference to another symbol. The other symbol
170 appears as an undefined reference, immediately following this symbol.
172 Indirection is asymmetrical. The other symbol's value will be used
173 to satisfy requests for the indirect symbol, but not vice versa.
174 If the other symbol does not have a definition, libraries will
175 be searched to find a definition. */
178 /* The following symbols refer to set elements.
179 All the N_SET[ATDB] symbols with the same name form one set.
180 Space is allocated for the set in the text section, and each set
181 element's value is stored into one word of the space.
182 The first word of the space is the length of the set (number of elements).
184 The address of the set is made into an N_SETV symbol
185 whose name is the same as the name of the set.
186 This symbol acts like a N_DATA global symbol
187 in that it can satisfy undefined external references. */
189 /* These appear as input to LD, in a .o file. */
190 #define N_SETA 0x14 /* Absolute set element symbol */
191 #define N_SETT 0x16 /* Text set element symbol */
192 #define N_SETD 0x18 /* Data set element symbol */
193 #define N_SETB 0x1A /* Bss set element symbol */
195 /* This is output from LD. */
196 #define N_SETV 0x1C /* Pointer to set vector in data area. */
198 /* This structure describes a single relocation to be performed.
199 The text-relocation section of the file is a vector of these structures,
200 all of which apply to the text section.
201 Likewise, the data-relocation section applies to the data section. */
203 /* The following enum and struct were borrowed from SunOS's
204 /usr/include/sun4/a.out.h and extended to handle
205 other machines. It is currently used on SPARC and AMD 29000.
207 reloc_ext_bytes is how it looks on disk. reloc_info_extended is
208 how we might process it on a native host. */
210 struct reloc_ext_bytes {
211 unsigned char r_address[4];
212 unsigned char r_index[3];
213 unsigned char r_bits[1];
214 unsigned char r_addend[4];
217 #define RELOC_EXT_BITS_EXTERN_BIG 0x80
218 #define RELOC_EXT_BITS_EXTERN_LITTLE 0x01
220 #define RELOC_EXT_BITS_TYPE_BIG 0x1F
221 #define RELOC_EXT_BITS_TYPE_SH_BIG 0
222 #define RELOC_EXT_BITS_TYPE_LITTLE 0xF8
223 #define RELOC_EXT_BITS_TYPE_SH_LITTLE 3
225 #define RELOC_EXT_SIZE 12 /* Bytes per relocation entry */
227 struct reloc_info_extended
229 unsigned long r_address;
230 unsigned int r_index:24;
231 # define r_symbolnum r_index
234 enum reloc_type r_type:5;
238 /* The standard, old-fashioned, Berkeley compatible relocation struct */
240 struct reloc_std_bytes {
241 unsigned char r_address[4];
242 unsigned char r_index[3];
243 unsigned char r_bits[1];
246 #define RELOC_STD_BITS_PCREL_BIG 0x80
247 #define RELOC_STD_BITS_PCREL_LITTLE 0x01
249 #define RELOC_STD_BITS_LENGTH_BIG 0x60
250 #define RELOC_STD_BITS_LENGTH_SH_BIG 5 /* To shift to units place */
251 #define RELOC_STD_BITS_LENGTH_LITTLE 0x06
252 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1
254 #define RELOC_STD_BITS_EXTERN_BIG 0x10
255 #define RELOC_STD_BITS_EXTERN_LITTLE 0x08
257 #define RELOC_STD_BITS_BASEREL_BIG 0x08
258 #define RELOC_STD_BITS_BASEREL_LITTLE 0x08
260 #define RELOC_STD_BITS_JMPTABLE_BIG 0x04
261 #define RELOC_STD_BITS_JMPTABLE_LITTLE 0x04
263 #define RELOC_STD_BITS_RELATIVE_BIG 0x02
264 #define RELOC_STD_BITS_RELATIVE_LITTLE 0x02
266 #define RELOC_STD_SIZE 8 /* Bytes per relocation entry */
268 struct relocation_info
270 /* Address (within segment) to be relocated. */
272 /* The meaning of r_symbolnum depends on r_extern. */
273 unsigned int r_symbolnum:24;
274 /* Nonzero means value is a pc-relative offset
275 and it should be relocated for changes in its own address
276 as well as for changes in the symbol or section specified. */
277 unsigned int r_pcrel:1;
278 /* Length (as exponent of 2) of the field to be relocated.
279 Thus, a value of 2 indicates 1<<2 bytes. */
280 unsigned int r_length:2;
281 /* 1 => relocate with value of symbol.
282 r_symbolnum is the index of the symbol
283 in file's the symbol table.
284 0 => relocate with the address of a segment.
285 r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
286 (the N_EXT bit may be set also, but signifies nothing). */
287 unsigned int r_extern:1;
288 /* The next three bits are for SunOS shared libraries, and seem to
290 unsigned int r_baserel:1; /* Linkage table relative */
291 unsigned int r_jmptable:1; /* pc-relative to jump table */
292 unsigned int r_relative:1; /* "relative relocation" */
294 unsigned int r_pad:1; /* Padding -- set to zero */
297 #endif /* __A_OUT_GNU_H__ */