linux-headers (unknown)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /* This file is derived from the GAS 2.1.4 assembler control file.
3 The GAS product is under the GNU General Public License, version 2 or later.
4 As such, this file is also under that license.
5
6 If the file format changes in the COFF object, this file should be
7 subsequently updated to reflect the changes.
8
9 The actual loader module only uses a few of these structures. The full
10 set is documented here because I received the full set. If you wish
11 more information about COFF, then O'Reilly has a very excellent book.
12 */
13
14 #ifndef _LINUX_COFF_H
15 #define _LINUX_COFF_H
16
17 #define E_SYMNMLEN 8 /* Number of characters in a symbol name */
18 #define E_FILNMLEN 14 /* Number of characters in a file name */
19 #define E_DIMNUM 4 /* Number of array dimensions in auxiliary entry */
20
21 /*
22 * These defines are byte order independent. There is no alignment of fields
23 * permitted in the structures. Therefore they are declared as characters
24 * and the values loaded from the character positions. It also makes it
25 * nice to have it "endian" independent.
26 */
27
28 /* Load a short int from the following tables with little-endian formats */
29 #define COFF_SHORT_L(ps) ((short)(((unsigned short)((unsigned char)ps[1])<<8)|\
30 ((unsigned short)((unsigned char)ps[0]))))
31
32 /* Load a long int from the following tables with little-endian formats */
33 #define COFF_LONG_L(ps) (((long)(((unsigned long)((unsigned char)ps[3])<<24) |\
34 ((unsigned long)((unsigned char)ps[2])<<16) |\
35 ((unsigned long)((unsigned char)ps[1])<<8) |\
36 ((unsigned long)((unsigned char)ps[0])))))
37
38 /* Load a short int from the following tables with big-endian formats */
39 #define COFF_SHORT_H(ps) ((short)(((unsigned short)((unsigned char)ps[0])<<8)|\
40 ((unsigned short)((unsigned char)ps[1]))))
41
42 /* Load a long int from the following tables with big-endian formats */
43 #define COFF_LONG_H(ps) (((long)(((unsigned long)((unsigned char)ps[0])<<24) |\
44 ((unsigned long)((unsigned char)ps[1])<<16) |\
45 ((unsigned long)((unsigned char)ps[2])<<8) |\
46 ((unsigned long)((unsigned char)ps[3])))))
47
48 /* These may be overridden later by brain dead implementations which generate
49 a big-endian header with little-endian data. In that case, generate a
50 replacement macro which tests a flag and uses either of the two above
51 as appropriate. */
52
53 #define COFF_LONG(v) COFF_LONG_L(v)
54 #define COFF_SHORT(v) COFF_SHORT_L(v)
55
56 /*** coff information for Intel 386/486. */
57
58 /********************** FILE HEADER **********************/
59
60 struct COFF_filehdr {
61 char f_magic[2]; /* magic number */
62 char f_nscns[2]; /* number of sections */
63 char f_timdat[4]; /* time & date stamp */
64 char f_symptr[4]; /* file pointer to symtab */
65 char f_nsyms[4]; /* number of symtab entries */
66 char f_opthdr[2]; /* sizeof(optional hdr) */
67 char f_flags[2]; /* flags */
68 };
69
70 /*
71 * Bits for f_flags:
72 *
73 * F_RELFLG relocation info stripped from file
74 * F_EXEC file is executable (i.e. no unresolved external
75 * references)
76 * F_LNNO line numbers stripped from file
77 * F_LSYMS local symbols stripped from file
78 * F_MINMAL this is a minimal object file (".m") output of fextract
79 * F_UPDATE this is a fully bound update file, output of ogen
80 * F_SWABD this file has had its bytes swabbed (in names)
81 * F_AR16WR this file has the byte ordering of an AR16WR
82 * (e.g. 11/70) machine
83 * F_AR32WR this file has the byte ordering of an AR32WR machine
84 * (e.g. vax and iNTEL 386)
85 * F_AR32W this file has the byte ordering of an AR32W machine
86 * (e.g. 3b,maxi)
87 * F_PATCH file contains "patch" list in optional header
88 * F_NODF (minimal file only) no decision functions for
89 * replaced functions
90 */
91
92 #define COFF_F_RELFLG 0000001
93 #define COFF_F_EXEC 0000002
94 #define COFF_F_LNNO 0000004
95 #define COFF_F_LSYMS 0000010
96 #define COFF_F_MINMAL 0000020
97 #define COFF_F_UPDATE 0000040
98 #define COFF_F_SWABD 0000100
99 #define COFF_F_AR16WR 0000200
100 #define COFF_F_AR32WR 0000400
101 #define COFF_F_AR32W 0001000
102 #define COFF_F_PATCH 0002000
103 #define COFF_F_NODF 0002000
104
105 #define COFF_I386MAGIC 0x14c /* Linux's system */
106
107 #if 0 /* Perhaps, someday, these formats may be used. */
108 #define COFF_I386PTXMAGIC 0x154
109 #define COFF_I386AIXMAGIC 0x175 /* IBM's AIX system */
110 #define COFF_I386BADMAG(x) ((COFF_SHORT((x).f_magic) != COFF_I386MAGIC) \
111 && COFF_SHORT((x).f_magic) != COFF_I386PTXMAGIC \
112 && COFF_SHORT((x).f_magic) != COFF_I386AIXMAGIC)
113 #else
114 #define COFF_I386BADMAG(x) (COFF_SHORT((x).f_magic) != COFF_I386MAGIC)
115 #endif
116
117 #define COFF_FILHDR struct COFF_filehdr
118 #define COFF_FILHSZ sizeof(COFF_FILHDR)
119
120 /********************** AOUT "OPTIONAL HEADER" **********************/
121
122 /* Linux COFF must have this "optional" header. Standard COFF has no entry
123 location for the "entry" point. They normally would start with the first
124 location of the .text section. This is not a good idea for linux. So,
125 the use of this "optional" header is not optional. It is required.
126
127 Do not be tempted to assume that the size of the optional header is
128 a constant and simply index the next byte by the size of this structure.
129 Use the 'f_opthdr' field in the main coff header for the size of the
130 structure actually written to the file!!
131 */
132
133 typedef struct
134 {
135 char magic[2]; /* type of file */
136 char vstamp[2]; /* version stamp */
137 char tsize[4]; /* text size in bytes, padded to FW bdry */
138 char dsize[4]; /* initialized data " " */
139 char bsize[4]; /* uninitialized data " " */
140 char entry[4]; /* entry pt. */
141 char text_start[4]; /* base of text used for this file */
142 char data_start[4]; /* base of data used for this file */
143 }
144 COFF_AOUTHDR;
145
146 #define COFF_AOUTSZ (sizeof(COFF_AOUTHDR))
147
148 #define COFF_STMAGIC 0401
149 #define COFF_OMAGIC 0404
150 #define COFF_JMAGIC 0407 /* dirty text and data image, can't share */
151 #define COFF_DMAGIC 0410 /* dirty text segment, data aligned */
152 #define COFF_ZMAGIC 0413 /* The proper magic number for executables */
153 #define COFF_SHMAGIC 0443 /* shared library header */
154
155 /********************** SECTION HEADER **********************/
156
157 struct COFF_scnhdr {
158 char s_name[8]; /* section name */
159 char s_paddr[4]; /* physical address, aliased s_nlib */
160 char s_vaddr[4]; /* virtual address */
161 char s_size[4]; /* section size */
162 char s_scnptr[4]; /* file ptr to raw data for section */
163 char s_relptr[4]; /* file ptr to relocation */
164 char s_lnnoptr[4]; /* file ptr to line numbers */
165 char s_nreloc[2]; /* number of relocation entries */
166 char s_nlnno[2]; /* number of line number entries */
167 char s_flags[4]; /* flags */
168 };
169
170 #define COFF_SCNHDR struct COFF_scnhdr
171 #define COFF_SCNHSZ sizeof(COFF_SCNHDR)
172
173 /*
174 * names of "special" sections
175 */
176
177 #define COFF_TEXT ".text"
178 #define COFF_DATA ".data"
179 #define COFF_BSS ".bss"
180 #define COFF_COMMENT ".comment"
181 #define COFF_LIB ".lib"
182
183 #define COFF_SECT_TEXT 0 /* Section for instruction code */
184 #define COFF_SECT_DATA 1 /* Section for initialized globals */
185 #define COFF_SECT_BSS 2 /* Section for un-initialized globals */
186 #define COFF_SECT_REQD 3 /* Minimum number of sections for good file */
187
188 #define COFF_STYP_REG 0x00 /* regular segment */
189 #define COFF_STYP_DSECT 0x01 /* dummy segment */
190 #define COFF_STYP_NOLOAD 0x02 /* no-load segment */
191 #define COFF_STYP_GROUP 0x04 /* group segment */
192 #define COFF_STYP_PAD 0x08 /* .pad segment */
193 #define COFF_STYP_COPY 0x10 /* copy section */
194 #define COFF_STYP_TEXT 0x20 /* .text segment */
195 #define COFF_STYP_DATA 0x40 /* .data segment */
196 #define COFF_STYP_BSS 0x80 /* .bss segment */
197 #define COFF_STYP_INFO 0x200 /* .comment section */
198 #define COFF_STYP_OVER 0x400 /* overlay section */
199 #define COFF_STYP_LIB 0x800 /* library section */
200
201 /*
202 * Shared libraries have the following section header in the data field for
203 * each library.
204 */
205
206 struct COFF_slib {
207 char sl_entsz[4]; /* Size of this entry */
208 char sl_pathndx[4]; /* size of the header field */
209 };
210
211 #define COFF_SLIBHD struct COFF_slib
212 #define COFF_SLIBSZ sizeof(COFF_SLIBHD)
213
214 /********************** LINE NUMBERS **********************/
215
216 /* 1 line number entry for every "breakpointable" source line in a section.
217 * Line numbers are grouped on a per function basis; first entry in a function
218 * grouping will have l_lnno = 0 and in place of physical address will be the
219 * symbol table index of the function name.
220 */
221
222 struct COFF_lineno {
223 union {
224 char l_symndx[4]; /* function name symbol index, iff l_lnno == 0*/
225 char l_paddr[4]; /* (physical) address of line number */
226 } l_addr;
227 char l_lnno[2]; /* line number */
228 };
229
230 #define COFF_LINENO struct COFF_lineno
231 #define COFF_LINESZ 6
232
233 /********************** SYMBOLS **********************/
234
235 #define COFF_E_SYMNMLEN 8 /* # characters in a short symbol name */
236 #define COFF_E_FILNMLEN 14 /* # characters in a file name */
237 #define COFF_E_DIMNUM 4 /* # array dimensions in auxiliary entry */
238
239 /*
240 * All symbols and sections have the following definition
241 */
242
243 struct COFF_syment
244 {
245 union {
246 char e_name[E_SYMNMLEN]; /* Symbol name (first 8 characters) */
247 struct {
248 char e_zeroes[4]; /* Leading zeros */
249 char e_offset[4]; /* Offset if this is a header section */
250 } e;
251 } e;
252
253 char e_value[4]; /* Value (address) of the segment */
254 char e_scnum[2]; /* Section number */
255 char e_type[2]; /* Type of section */
256 char e_sclass[1]; /* Loader class */
257 char e_numaux[1]; /* Number of auxiliary entries which follow */
258 };
259
260 #define COFF_N_BTMASK (0xf) /* Mask for important class bits */
261 #define COFF_N_TMASK (0x30) /* Mask for important type bits */
262 #define COFF_N_BTSHFT (4) /* # bits to shift class field */
263 #define COFF_N_TSHIFT (2) /* # bits to shift type field */
264
265 /*
266 * Auxiliary entries because the main table is too limiting.
267 */
268
269 union COFF_auxent {
270
271 /*
272 * Debugger information
273 */
274
275 struct {
276 char x_tagndx[4]; /* str, un, or enum tag indx */
277 union {
278 struct {
279 char x_lnno[2]; /* declaration line number */
280 char x_size[2]; /* str/union/array size */
281 } x_lnsz;
282 char x_fsize[4]; /* size of function */
283 } x_misc;
284
285 union {
286 struct { /* if ISFCN, tag, or .bb */
287 char x_lnnoptr[4]; /* ptr to fcn line # */
288 char x_endndx[4]; /* entry ndx past block end */
289 } x_fcn;
290
291 struct { /* if ISARY, up to 4 dimen. */
292 char x_dimen[E_DIMNUM][2];
293 } x_ary;
294 } x_fcnary;
295
296 char x_tvndx[2]; /* tv index */
297 } x_sym;
298
299 /*
300 * Source file names (debugger information)
301 */
302
303 union {
304 char x_fname[E_FILNMLEN];
305 struct {
306 char x_zeroes[4];
307 char x_offset[4];
308 } x_n;
309 } x_file;
310
311 /*
312 * Section information
313 */
314
315 struct {
316 char x_scnlen[4]; /* section length */
317 char x_nreloc[2]; /* # relocation entries */
318 char x_nlinno[2]; /* # line numbers */
319 } x_scn;
320
321 /*
322 * Transfer vector (branch table)
323 */
324
325 struct {
326 char x_tvfill[4]; /* tv fill value */
327 char x_tvlen[2]; /* length of .tv */
328 char x_tvran[2][2]; /* tv range */
329 } x_tv; /* info about .tv section (in auxent of symbol .tv)) */
330 };
331
332 #define COFF_SYMENT struct COFF_syment
333 #define COFF_SYMESZ 18
334 #define COFF_AUXENT union COFF_auxent
335 #define COFF_AUXESZ 18
336
337 #define COFF_ETEXT "etext"
338
339 /********************** RELOCATION DIRECTIVES **********************/
340
341 struct COFF_reloc {
342 char r_vaddr[4]; /* Virtual address of item */
343 char r_symndx[4]; /* Symbol index in the symtab */
344 char r_type[2]; /* Relocation type */
345 };
346
347 #define COFF_RELOC struct COFF_reloc
348 #define COFF_RELSZ 10
349
350 #define COFF_DEF_DATA_SECTION_ALIGNMENT 4
351 #define COFF_DEF_BSS_SECTION_ALIGNMENT 4
352 #define COFF_DEF_TEXT_SECTION_ALIGNMENT 4
353
354 /* For new sections we haven't heard of before */
355 #define COFF_DEF_SECTION_ALIGNMENT 4
356
357 #endif /* _LINUX_COFF_H */
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