]>
Commit | Line | Data |
---|---|---|
e2be04c7 | 1 | /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
1da177e4 LT |
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 | #define E_SYMNMLEN 8 /* Number of characters in a symbol name */ | |
15 | #define E_FILNMLEN 14 /* Number of characters in a file name */ | |
16 | #define E_DIMNUM 4 /* Number of array dimensions in auxiliary entry */ | |
17 | ||
18 | /* | |
19 | * These defines are byte order independent. There is no alignment of fields | |
20 | * permitted in the structures. Therefore they are declared as characters | |
21 | * and the values loaded from the character positions. It also makes it | |
22 | * nice to have it "endian" independent. | |
23 | */ | |
24 | ||
25 | /* Load a short int from the following tables with little-endian formats */ | |
26 | #define COFF_SHORT_L(ps) ((short)(((unsigned short)((unsigned char)ps[1])<<8)|\ | |
27 | ((unsigned short)((unsigned char)ps[0])))) | |
28 | ||
29 | /* Load a long int from the following tables with little-endian formats */ | |
30 | #define COFF_LONG_L(ps) (((long)(((unsigned long)((unsigned char)ps[3])<<24) |\ | |
31 | ((unsigned long)((unsigned char)ps[2])<<16) |\ | |
32 | ((unsigned long)((unsigned char)ps[1])<<8) |\ | |
33 | ((unsigned long)((unsigned char)ps[0]))))) | |
34 | ||
35 | /* Load a short int from the following tables with big-endian formats */ | |
36 | #define COFF_SHORT_H(ps) ((short)(((unsigned short)((unsigned char)ps[0])<<8)|\ | |
37 | ((unsigned short)((unsigned char)ps[1])))) | |
38 | ||
39 | /* Load a long int from the following tables with big-endian formats */ | |
40 | #define COFF_LONG_H(ps) (((long)(((unsigned long)((unsigned char)ps[0])<<24) |\ | |
41 | ((unsigned long)((unsigned char)ps[1])<<16) |\ | |
42 | ((unsigned long)((unsigned char)ps[2])<<8) |\ | |
43 | ((unsigned long)((unsigned char)ps[3]))))) | |
44 | ||
45 | /* These may be overridden later by brain dead implementations which generate | |
46 | a big-endian header with little-endian data. In that case, generate a | |
47 | replacement macro which tests a flag and uses either of the two above | |
48 | as appropriate. */ | |
49 | ||
50 | #define COFF_LONG(v) COFF_LONG_L(v) | |
51 | #define COFF_SHORT(v) COFF_SHORT_L(v) | |
52 | ||
53 | /*** coff information for Intel 386/486. */ | |
54 | ||
55 | /********************** FILE HEADER **********************/ | |
56 | ||
57 | struct COFF_filehdr { | |
58 | char f_magic[2]; /* magic number */ | |
59 | char f_nscns[2]; /* number of sections */ | |
60 | char f_timdat[4]; /* time & date stamp */ | |
61 | char f_symptr[4]; /* file pointer to symtab */ | |
62 | char f_nsyms[4]; /* number of symtab entries */ | |
63 | char f_opthdr[2]; /* sizeof(optional hdr) */ | |
64 | char f_flags[2]; /* flags */ | |
65 | }; | |
66 | ||
67 | /* | |
68 | * Bits for f_flags: | |
69 | * | |
70 | * F_RELFLG relocation info stripped from file | |
71 | * F_EXEC file is executable (i.e. no unresolved external | |
72 | * references) | |
73 | * F_LNNO line numbers stripped from file | |
74 | * F_LSYMS local symbols stripped from file | |
75 | * F_MINMAL this is a minimal object file (".m") output of fextract | |
76 | * F_UPDATE this is a fully bound update file, output of ogen | |
77 | * F_SWABD this file has had its bytes swabbed (in names) | |
78 | * F_AR16WR this file has the byte ordering of an AR16WR | |
79 | * (e.g. 11/70) machine | |
80 | * F_AR32WR this file has the byte ordering of an AR32WR machine | |
81 | * (e.g. vax and iNTEL 386) | |
82 | * F_AR32W this file has the byte ordering of an AR32W machine | |
83 | * (e.g. 3b,maxi) | |
84 | * F_PATCH file contains "patch" list in optional header | |
85 | * F_NODF (minimal file only) no decision functions for | |
86 | * replaced functions | |
87 | */ | |
88 | ||
89 | #define COFF_F_RELFLG 0000001 | |
90 | #define COFF_F_EXEC 0000002 | |
91 | #define COFF_F_LNNO 0000004 | |
92 | #define COFF_F_LSYMS 0000010 | |
93 | #define COFF_F_MINMAL 0000020 | |
94 | #define COFF_F_UPDATE 0000040 | |
95 | #define COFF_F_SWABD 0000100 | |
96 | #define COFF_F_AR16WR 0000200 | |
97 | #define COFF_F_AR32WR 0000400 | |
98 | #define COFF_F_AR32W 0001000 | |
99 | #define COFF_F_PATCH 0002000 | |
100 | #define COFF_F_NODF 0002000 | |
101 | ||
102 | #define COFF_I386MAGIC 0x14c /* Linux's system */ | |
103 | ||
104 | #if 0 /* Perhaps, someday, these formats may be used. */ | |
105 | #define COFF_I386PTXMAGIC 0x154 | |
106 | #define COFF_I386AIXMAGIC 0x175 /* IBM's AIX system */ | |
107 | #define COFF_I386BADMAG(x) ((COFF_SHORT((x).f_magic) != COFF_I386MAGIC) \ | |
108 | && COFF_SHORT((x).f_magic) != COFF_I386PTXMAGIC \ | |
109 | && COFF_SHORT((x).f_magic) != COFF_I386AIXMAGIC) | |
110 | #else | |
111 | #define COFF_I386BADMAG(x) (COFF_SHORT((x).f_magic) != COFF_I386MAGIC) | |
112 | #endif | |
113 | ||
114 | #define COFF_FILHDR struct COFF_filehdr | |
115 | #define COFF_FILHSZ sizeof(COFF_FILHDR) | |
116 | ||
117 | /********************** AOUT "OPTIONAL HEADER" **********************/ | |
118 | ||
119 | /* Linux COFF must have this "optional" header. Standard COFF has no entry | |
120 | location for the "entry" point. They normally would start with the first | |
121 | location of the .text section. This is not a good idea for linux. So, | |
122 | the use of this "optional" header is not optional. It is required. | |
123 | ||
124 | Do not be tempted to assume that the size of the optional header is | |
125 | a constant and simply index the next byte by the size of this structure. | |
126 | Use the 'f_opthdr' field in the main coff header for the size of the | |
127 | structure actually written to the file!! | |
128 | */ | |
129 | ||
130 | typedef struct | |
131 | { | |
132 | char magic[2]; /* type of file */ | |
133 | char vstamp[2]; /* version stamp */ | |
134 | char tsize[4]; /* text size in bytes, padded to FW bdry */ | |
135 | char dsize[4]; /* initialized data " " */ | |
136 | char bsize[4]; /* uninitialized data " " */ | |
137 | char entry[4]; /* entry pt. */ | |
138 | char text_start[4]; /* base of text used for this file */ | |
139 | char data_start[4]; /* base of data used for this file */ | |
140 | } | |
141 | COFF_AOUTHDR; | |
142 | ||
143 | #define COFF_AOUTSZ (sizeof(COFF_AOUTHDR)) | |
144 | ||
145 | #define COFF_STMAGIC 0401 | |
146 | #define COFF_OMAGIC 0404 | |
147 | #define COFF_JMAGIC 0407 /* dirty text and data image, can't share */ | |
148 | #define COFF_DMAGIC 0410 /* dirty text segment, data aligned */ | |
149 | #define COFF_ZMAGIC 0413 /* The proper magic number for executables */ | |
150 | #define COFF_SHMAGIC 0443 /* shared library header */ | |
151 | ||
152 | /********************** SECTION HEADER **********************/ | |
153 | ||
154 | struct COFF_scnhdr { | |
155 | char s_name[8]; /* section name */ | |
156 | char s_paddr[4]; /* physical address, aliased s_nlib */ | |
157 | char s_vaddr[4]; /* virtual address */ | |
158 | char s_size[4]; /* section size */ | |
159 | char s_scnptr[4]; /* file ptr to raw data for section */ | |
160 | char s_relptr[4]; /* file ptr to relocation */ | |
161 | char s_lnnoptr[4]; /* file ptr to line numbers */ | |
162 | char s_nreloc[2]; /* number of relocation entries */ | |
163 | char s_nlnno[2]; /* number of line number entries */ | |
164 | char s_flags[4]; /* flags */ | |
165 | }; | |
166 | ||
167 | #define COFF_SCNHDR struct COFF_scnhdr | |
168 | #define COFF_SCNHSZ sizeof(COFF_SCNHDR) | |
169 | ||
170 | /* | |
171 | * names of "special" sections | |
172 | */ | |
173 | ||
174 | #define COFF_TEXT ".text" | |
175 | #define COFF_DATA ".data" | |
176 | #define COFF_BSS ".bss" | |
177 | #define COFF_COMMENT ".comment" | |
178 | #define COFF_LIB ".lib" | |
179 | ||
180 | #define COFF_SECT_TEXT 0 /* Section for instruction code */ | |
181 | #define COFF_SECT_DATA 1 /* Section for initialized globals */ | |
182 | #define COFF_SECT_BSS 2 /* Section for un-initialized globals */ | |
183 | #define COFF_SECT_REQD 3 /* Minimum number of sections for good file */ | |
184 | ||
185 | #define COFF_STYP_REG 0x00 /* regular segment */ | |
186 | #define COFF_STYP_DSECT 0x01 /* dummy segment */ | |
187 | #define COFF_STYP_NOLOAD 0x02 /* no-load segment */ | |
188 | #define COFF_STYP_GROUP 0x04 /* group segment */ | |
189 | #define COFF_STYP_PAD 0x08 /* .pad segment */ | |
190 | #define COFF_STYP_COPY 0x10 /* copy section */ | |
191 | #define COFF_STYP_TEXT 0x20 /* .text segment */ | |
192 | #define COFF_STYP_DATA 0x40 /* .data segment */ | |
193 | #define COFF_STYP_BSS 0x80 /* .bss segment */ | |
194 | #define COFF_STYP_INFO 0x200 /* .comment section */ | |
195 | #define COFF_STYP_OVER 0x400 /* overlay section */ | |
196 | #define COFF_STYP_LIB 0x800 /* library section */ | |
197 | ||
198 | /* | |
199 | * Shared libraries have the following section header in the data field for | |
200 | * each library. | |
201 | */ | |
202 | ||
203 | struct COFF_slib { | |
204 | char sl_entsz[4]; /* Size of this entry */ | |
205 | char sl_pathndx[4]; /* size of the header field */ | |
206 | }; | |
207 | ||
208 | #define COFF_SLIBHD struct COFF_slib | |
209 | #define COFF_SLIBSZ sizeof(COFF_SLIBHD) | |
210 | ||
211 | /********************** LINE NUMBERS **********************/ | |
212 | ||
213 | /* 1 line number entry for every "breakpointable" source line in a section. | |
214 | * Line numbers are grouped on a per function basis; first entry in a function | |
215 | * grouping will have l_lnno = 0 and in place of physical address will be the | |
216 | * symbol table index of the function name. | |
217 | */ | |
218 | ||
219 | struct COFF_lineno { | |
220 | union { | |
221 | char l_symndx[4]; /* function name symbol index, iff l_lnno == 0*/ | |
222 | char l_paddr[4]; /* (physical) address of line number */ | |
223 | } l_addr; | |
224 | char l_lnno[2]; /* line number */ | |
225 | }; | |
226 | ||
227 | #define COFF_LINENO struct COFF_lineno | |
228 | #define COFF_LINESZ 6 | |
229 | ||
230 | /********************** SYMBOLS **********************/ | |
231 | ||
232 | #define COFF_E_SYMNMLEN 8 /* # characters in a short symbol name */ | |
233 | #define COFF_E_FILNMLEN 14 /* # characters in a file name */ | |
234 | #define COFF_E_DIMNUM 4 /* # array dimensions in auxiliary entry */ | |
235 | ||
236 | /* | |
237 | * All symbols and sections have the following definition | |
238 | */ | |
239 | ||
240 | struct COFF_syment | |
241 | { | |
242 | union { | |
243 | char e_name[E_SYMNMLEN]; /* Symbol name (first 8 characters) */ | |
244 | struct { | |
245 | char e_zeroes[4]; /* Leading zeros */ | |
246 | char e_offset[4]; /* Offset if this is a header section */ | |
247 | } e; | |
248 | } e; | |
249 | ||
250 | char e_value[4]; /* Value (address) of the segment */ | |
251 | char e_scnum[2]; /* Section number */ | |
252 | char e_type[2]; /* Type of section */ | |
253 | char e_sclass[1]; /* Loader class */ | |
254 | char e_numaux[1]; /* Number of auxiliary entries which follow */ | |
255 | }; | |
256 | ||
257 | #define COFF_N_BTMASK (0xf) /* Mask for important class bits */ | |
258 | #define COFF_N_TMASK (0x30) /* Mask for important type bits */ | |
259 | #define COFF_N_BTSHFT (4) /* # bits to shift class field */ | |
260 | #define COFF_N_TSHIFT (2) /* # bits to shift type field */ | |
261 | ||
262 | /* | |
263 | * Auxiliary entries because the main table is too limiting. | |
264 | */ | |
265 | ||
266 | union COFF_auxent { | |
267 | ||
268 | /* | |
269 | * Debugger information | |
270 | */ | |
271 | ||
272 | struct { | |
273 | char x_tagndx[4]; /* str, un, or enum tag indx */ | |
274 | union { | |
275 | struct { | |
276 | char x_lnno[2]; /* declaration line number */ | |
277 | char x_size[2]; /* str/union/array size */ | |
278 | } x_lnsz; | |
279 | char x_fsize[4]; /* size of function */ | |
280 | } x_misc; | |
281 | ||
282 | union { | |
283 | struct { /* if ISFCN, tag, or .bb */ | |
284 | char x_lnnoptr[4]; /* ptr to fcn line # */ | |
285 | char x_endndx[4]; /* entry ndx past block end */ | |
286 | } x_fcn; | |
287 | ||
288 | struct { /* if ISARY, up to 4 dimen. */ | |
289 | char x_dimen[E_DIMNUM][2]; | |
290 | } x_ary; | |
291 | } x_fcnary; | |
292 | ||
293 | char x_tvndx[2]; /* tv index */ | |
294 | } x_sym; | |
295 | ||
296 | /* | |
297 | * Source file names (debugger information) | |
298 | */ | |
299 | ||
300 | union { | |
301 | char x_fname[E_FILNMLEN]; | |
302 | struct { | |
303 | char x_zeroes[4]; | |
304 | char x_offset[4]; | |
305 | } x_n; | |
306 | } x_file; | |
307 | ||
308 | /* | |
309 | * Section information | |
310 | */ | |
311 | ||
312 | struct { | |
313 | char x_scnlen[4]; /* section length */ | |
314 | char x_nreloc[2]; /* # relocation entries */ | |
315 | char x_nlinno[2]; /* # line numbers */ | |
316 | } x_scn; | |
317 | ||
318 | /* | |
319 | * Transfer vector (branch table) | |
320 | */ | |
321 | ||
322 | struct { | |
323 | char x_tvfill[4]; /* tv fill value */ | |
324 | char x_tvlen[2]; /* length of .tv */ | |
325 | char x_tvran[2][2]; /* tv range */ | |
326 | } x_tv; /* info about .tv section (in auxent of symbol .tv)) */ | |
327 | }; | |
328 | ||
329 | #define COFF_SYMENT struct COFF_syment | |
330 | #define COFF_SYMESZ 18 | |
331 | #define COFF_AUXENT union COFF_auxent | |
332 | #define COFF_AUXESZ 18 | |
333 | ||
334 | #define COFF_ETEXT "etext" | |
335 | ||
336 | /********************** RELOCATION DIRECTIVES **********************/ | |
337 | ||
338 | struct COFF_reloc { | |
339 | char r_vaddr[4]; /* Virtual address of item */ | |
340 | char r_symndx[4]; /* Symbol index in the symtab */ | |
341 | char r_type[2]; /* Relocation type */ | |
342 | }; | |
343 | ||
344 | #define COFF_RELOC struct COFF_reloc | |
345 | #define COFF_RELSZ 10 | |
346 | ||
347 | #define COFF_DEF_DATA_SECTION_ALIGNMENT 4 | |
348 | #define COFF_DEF_BSS_SECTION_ALIGNMENT 4 | |
349 | #define COFF_DEF_TEXT_SECTION_ALIGNMENT 4 | |
350 | ||
351 | /* For new sections we haven't heard of before */ | |
352 | #define COFF_DEF_SECTION_ALIGNMENT 4 |