3a69b3ac |
1 | /* b.out object file format |
2 | Copyright (C) 1989, 1990, 1991 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GAS, the GNU Assembler. |
5 | |
6 | GAS is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as |
8 | published by the Free Software Foundation; either version 1, |
9 | or (at your option) any later version. |
10 | |
11 | GAS is distributed in the hope that it will be useful, but |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
14 | the GNU General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU General Public |
17 | License along with GAS; see the file COPYING. If not, write |
18 | to the Free Software Foundation, 675 Mass Ave, Cambridge, MA |
19 | 02139, USA. */ |
20 | |
21 | /* $Id$ */ |
22 | |
23 | /* |
24 | * This file is a modified version of 'a.out.h'. It is to be used in all GNU |
25 | * tools modified to support the i80960 b.out format (or tools that operate on |
26 | * object files created by such tools). |
27 | * |
28 | * All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e., |
29 | * object code is generated on, and executed under the direction of a symbolic |
30 | * debugger running on, a host system. We do not want to be subject to the |
31 | * vagaries of which host it is or whether it supports COFF or a.out format, or |
32 | * anything else. We DO want to: |
33 | * |
34 | * o always generate the same format object files, regardless of host. |
35 | * |
36 | * o have an 'a.out' header that we can modify for our own purposes |
37 | * (the 80960 is typically an embedded processor and may require |
38 | * enhanced linker support that the normal a.out.h header can't |
39 | * accommodate). |
40 | * |
41 | * As for byte-ordering, the following rules apply: |
42 | * |
43 | * o Text and data that is actually downloaded to the target is always |
44 | * in i80960 (little-endian) order. |
45 | * |
46 | * o All other numbers (in the header, symbols, relocation directives) |
47 | * are in host byte-order: object files CANNOT be lifted from a |
48 | * little-end host and used on a big-endian (or vice versa) without |
49 | * modification. |
50 | * |
51 | * o The downloader ('comm960') takes care to generate a pseudo-header |
52 | * with correct (i80960) byte-ordering before shipping text and data |
53 | * off to the NINDY monitor in the target systems. Symbols and |
54 | * relocation info are never sent to the target. |
55 | */ |
56 | |
57 | |
58 | #define OBJ_BOUT 1 |
59 | |
60 | #include "targ-cpu.h" |
61 | |
62 | /* bout uses host byte order for headers */ |
63 | #ifdef CROSS_ASSEMBLE |
64 | #undef CROSS_ASSEMBLE |
65 | #endif /* CROSS_ASSEMBLE */ |
66 | |
67 | /* We want \v. */ |
68 | #define BACKSLASH_V 1 |
69 | |
70 | #define OBJ_DEFAULT_OUTPUT_FILE_NAME "b.out" |
71 | |
72 | extern const short seg_N_TYPE[]; |
73 | extern const segT N_TYPE_seg[]; |
74 | |
75 | #define BMAGIC 0415 |
76 | /* We don't accept the following (see N_BADMAG macro). |
77 | * They're just here so GNU code will compile. |
78 | */ |
79 | #define OMAGIC 0407 /* old impure format */ |
80 | #define NMAGIC 0410 /* read-only text */ |
81 | #define ZMAGIC 0413 /* demand load format */ |
82 | |
83 | #ifndef DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE |
84 | #define DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE (BMAGIC) |
85 | #endif /* DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE */ |
86 | |
87 | /* FILE HEADER |
88 | * All 'lengths' are given as a number of bytes. |
89 | * All 'alignments' are for relinkable files only; an alignment of |
90 | * 'n' indicates the corresponding segment must begin at an |
91 | * address that is a multiple of (2**n). |
92 | */ |
93 | struct exec { |
94 | /* Standard stuff */ |
95 | unsigned long a_magic; /* Identifies this as a b.out file */ |
96 | unsigned long a_text; /* Length of text */ |
97 | unsigned long a_data; /* Length of data */ |
98 | unsigned long a_bss; /* Length of runtime uninitialized data area */ |
99 | unsigned long a_syms; /* Length of symbol table */ |
100 | unsigned long a_entry; /* Runtime start address */ |
101 | unsigned long a_trsize; /* Length of text relocation info */ |
102 | unsigned long a_drsize; /* Length of data relocation info */ |
103 | |
104 | /* Added for i960 */ |
105 | unsigned long a_tload; /* Text runtime load address */ |
106 | unsigned long a_dload; /* Data runtime load address */ |
107 | unsigned char a_talign; /* Alignment of text segment */ |
108 | unsigned char a_dalign; /* Alignment of data segment */ |
109 | unsigned char a_balign; /* Alignment of bss segment */ |
110 | unsigned char unused; /* (Just to make struct size a multiple of 4) */ |
111 | }; |
112 | |
113 | #define N_BADMAG(x) (((x).a_magic)!=BMAGIC) |
114 | #define N_TXTOFF(x) ( sizeof(struct exec) ) |
115 | #define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text ) |
116 | #define N_TROFF(x) ( N_DATOFF(x) + (x).a_data ) |
117 | #define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize ) |
118 | #define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize ) |
119 | #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms ) |
120 | |
121 | /* A single entry in the symbol table |
122 | */ |
123 | struct nlist { |
124 | union { |
125 | char *n_name; |
126 | struct nlist *n_next; |
127 | long n_strx; /* Index into string table */ |
128 | } n_un; |
129 | unsigned char n_type; /* See below */ |
130 | char n_other; /* Used in i80960 support -- see below */ |
131 | short n_desc; |
132 | unsigned long n_value; |
133 | }; |
134 | |
135 | typedef struct nlist obj_symbol_type; |
136 | |
137 | /* Legal values of n_type |
138 | */ |
139 | #define N_UNDF 0 /* Undefined symbol */ |
140 | #define N_ABS 2 /* Absolute symbol */ |
141 | #define N_TEXT 4 /* Text symbol */ |
142 | #define N_DATA 6 /* Data symbol */ |
143 | #define N_BSS 8 /* BSS symbol */ |
144 | #define N_FN 31 /* Filename symbol */ |
145 | |
146 | #define N_EXT 1 /* External symbol (OR'd in with one of above) */ |
147 | #define N_TYPE 036 /* Mask for all the type bits */ |
148 | #define N_STAB 0340 /* Mask for all bits used for SDB entries */ |
149 | |
150 | #ifndef CUSTOM_RELOC_FORMAT |
151 | 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. |
158 | */ |
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 |
163 | */ |
164 | r_extern:1, |
165 | r_bsr:1, /* Something for the GNU NS32K assembler */ |
166 | r_disp:1, /* Something for the GNU NS32K assembler */ |
167 | r_callj:1, /* 1 if relocation target is an i960 'callj' */ |
168 | nuthin:1; /* Unused */ |
169 | }; |
170 | #endif /* CUSTOM_RELOC_FORMAT */ |
171 | |
172 | /* If compiler generate leading underscores, remove them. */ |
173 | |
174 | #ifndef STRIP_UNDERSCORE |
175 | #define STRIP_UNDERSCORE 0 |
176 | #endif /* STRIP_UNDERSCORE */ |
177 | |
178 | /* |
179 | * Macros to extract information from a symbol table entry. |
180 | * This syntaxic indirection allows independence regarding a.out or coff. |
181 | * The argument (s) of all these macros is a pointer to a symbol table entry. |
182 | */ |
183 | |
184 | /* Predicates */ |
185 | /* True if the symbol is external */ |
186 | #define S_IS_EXTERNAL(s) ((s)->sy_symbol.n_type & N_EXT) |
187 | |
188 | /* True if symbol has been defined, ie is in N_{TEXT,DATA,BSS,ABS} or N_EXT */ |
189 | #define S_IS_DEFINED(s) ((S_GET_TYPE(s) != N_UNDF) || (S_GET_DESC(s) != 0)) |
190 | #define S_IS_REGISTER(s) ((s)->sy_symbol.n_type == N_REGISTER) |
191 | |
192 | /* True if a debug special symbol entry */ |
193 | #define S_IS_DEBUG(s) ((s)->sy_symbol.n_type & N_STAB) |
194 | /* True if a symbol is local symbol name */ |
195 | /* A symbol name whose name begin with ^A is a gas internal pseudo symbol |
196 | nameless symbols come from .stab directives. */ |
197 | #define S_IS_LOCAL(s) (S_GET_NAME(s) && \ |
198 | !S_IS_DEBUG(s) && \ |
199 | (S_GET_NAME(s)[0] == '\001' || \ |
200 | (S_LOCAL_NAME(s) && !flagseen['L']))) |
201 | /* True if a symbol is not defined in this file */ |
202 | #define S_IS_EXTERN(s) ((s)->sy_symbol.n_type & N_EXT) |
203 | /* True if the symbol has been generated because of a .stabd directive */ |
204 | #define S_IS_STABD(s) (S_GET_NAME(s) == NULL) |
205 | |
206 | /* Accessors */ |
207 | /* The value of the symbol */ |
208 | #define S_GET_VALUE(s) ((long) ((s)->sy_symbol.n_value)) |
209 | /* The name of the symbol */ |
210 | #define S_GET_NAME(s) ((s)->sy_symbol.n_un.n_name) |
211 | /* The pointer to the string table */ |
212 | #define S_GET_OFFSET(s) ((s)->sy_symbol.n_un.n_strx) |
213 | /* The type of the symbol */ |
214 | #define S_GET_TYPE(s) ((s)->sy_symbol.n_type & N_TYPE) |
215 | /* The numeric value of the segment */ |
216 | #define S_GET_SEGMENT(s) (N_TYPE_seg[S_GET_TYPE(s)]) |
217 | /* The n_other expression value */ |
218 | #define S_GET_OTHER(s) ((s)->sy_symbol.n_other) |
219 | /* The n_desc expression value */ |
220 | #define S_GET_DESC(s) ((s)->sy_symbol.n_desc) |
221 | |
222 | /* Modifiers */ |
223 | /* Set the value of the symbol */ |
224 | #define S_SET_VALUE(s,v) ((s)->sy_symbol.n_value = (unsigned long) (v)) |
225 | /* Assume that a symbol cannot be simultaneously in more than on segment */ |
226 | /* set segment */ |
227 | #define S_SET_SEGMENT(s,seg) ((s)->sy_symbol.n_type &= ~N_TYPE,(s)->sy_symbol.n_type|=SEGMENT_TO_SYMBOL_TYPE(seg)) |
228 | /* The symbol is external */ |
229 | #define S_SET_EXTERNAL(s) ((s)->sy_symbol.n_type |= N_EXT) |
230 | /* The symbol is not external */ |
231 | #define S_CLEAR_EXTERNAL(s) ((s)->sy_symbol.n_type &= ~N_EXT) |
232 | /* Set the name of the symbol */ |
233 | #define S_SET_NAME(s,v) ((s)->sy_symbol.n_un.n_name = (v)) |
234 | /* Set the offset in the string table */ |
235 | #define S_SET_OFFSET(s,v) ((s)->sy_symbol.n_un.n_strx = (v)) |
236 | /* Set the n_other expression value */ |
237 | #define S_SET_OTHER(s,v) ((s)->sy_symbol.n_other = (v)) |
238 | /* Set the n_desc expression value */ |
239 | #define S_SET_DESC(s,v) ((s)->sy_symbol.n_desc = (v)) |
240 | |
241 | /* File header macro and type definition */ |
242 | |
243 | #define H_GET_FILE_SIZE(h) (sizeof(struct exec) + \ |
244 | H_GET_TEXT_SIZE(h) + H_GET_DATA_SIZE(h) + \ |
245 | H_GET_SYMBOL_TABLE_SIZE(h) + \ |
246 | H_GET_TEXT_RELOCATION_SIZE(h) + \ |
247 | H_GET_DATA_RELOCATION_SIZE(h) + \ |
248 | (h)->string_table_size) |
249 | |
250 | #define H_GET_TEXT_SIZE(h) ((h)->header.a_text) |
251 | #define H_GET_DATA_SIZE(h) ((h)->header.a_data) |
252 | #define H_GET_BSS_SIZE(h) ((h)->header.a_bss) |
253 | #define H_GET_TEXT_RELOCATION_SIZE(h) ((h)->header.a_trsize) |
254 | #define H_GET_DATA_RELOCATION_SIZE(h) ((h)->header.a_drsize) |
255 | #define H_GET_SYMBOL_TABLE_SIZE(h) ((h)->header.a_syms) |
256 | #define H_GET_MAGIC_NUMBER(h) ((h)->header.a_info) |
257 | #define H_GET_ENTRY_POINT(h) ((h)->header.a_entry) |
258 | #define H_GET_STRING_SIZE(h) ((h)->string_table_size) |
259 | #ifdef EXEC_MACHINE_TYPE |
260 | #define H_GET_MACHINE_TYPE(h) ((h)->header.a_machtype) |
261 | #endif /* EXEC_MACHINE_TYPE */ |
262 | #ifdef EXEC_VERSION |
263 | #define H_GET_VERSION(h) ((h)->header.a_version) |
264 | #endif /* EXEC_VERSION */ |
265 | |
266 | #define H_SET_TEXT_SIZE(h,v) ((h)->header.a_text = md_section_align(SEG_TEXT, (v))) |
267 | #define H_SET_DATA_SIZE(h,v) ((h)->header.a_data = md_section_align(SEG_DATA, (v))) |
268 | #define H_SET_BSS_SIZE(h,v) ((h)->header.a_bss = md_section_align(SEG_BSS, (v))) |
269 | |
270 | #define H_SET_RELOCATION_SIZE(h,t,d) (H_SET_TEXT_RELOCATION_SIZE((h),(t)),\ |
271 | H_SET_DATA_RELOCATION_SIZE((h),(d))) |
272 | |
273 | #define H_SET_TEXT_RELOCATION_SIZE(h,v) ((h)->header.a_trsize = (v)) |
274 | #define H_SET_DATA_RELOCATION_SIZE(h,v) ((h)->header.a_drsize = (v)) |
275 | #define H_SET_SYMBOL_TABLE_SIZE(h,v) ((h)->header.a_syms = (v) * \ |
276 | sizeof(struct nlist)) |
277 | |
278 | #define H_SET_MAGIC_NUMBER(h,v) ((h)->header.a_magic = (v)) |
279 | |
280 | #define H_SET_ENTRY_POINT(h,v) ((h)->header.a_entry = (v)) |
281 | #define H_SET_STRING_SIZE(h,v) ((h)->string_table_size = (v)) |
282 | #ifdef EXEC_MACHINE_TYPE |
283 | #define H_SET_MACHINE_TYPE(h,v) ((h)->header.a_machtype = (v)) |
284 | #endif /* EXEC_MACHINE_TYPE */ |
285 | #ifdef EXEC_VERSION |
286 | #define H_SET_VERSION(h,v) ((h)->header.a_version = (v)) |
287 | #endif /* EXEC_VERSION */ |
288 | |
289 | /* |
290 | * Current means for getting the name of a segment. |
291 | * This will change for infinite-segments support (e.g. COFF). |
292 | */ |
293 | #define segment_name(seg) ( seg_name[(int)(seg)] ) |
294 | extern char *const seg_name[]; |
295 | |
296 | typedef struct { |
297 | struct exec header; /* a.out header */ |
298 | long string_table_size; /* names + '\0' + sizeof(int) */ |
299 | } object_headers; |
300 | |
301 | /* unused hooks. */ |
302 | #define OBJ_EMIT_LINENO(a, b, c) ; |
303 | #define obj_pre_write_hook(a) ; |
304 | |
305 | /* |
306 | * Local Variables: |
307 | * comment-column: 0 |
308 | * fill-column: 131 |
309 | * End: |
310 | */ |
311 | |
312 | /* end of obj-bout.h */ |