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 ".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 */ |
358 | |