source: svn/trunk/newcon3bcm2_21bu/toolchain/mips-linux-uclibc/include/linux/coff.h @ 8

Last change on this file since 8 was 2, checked in by jglee, 11 years ago

first commit
  • Property svn:executable set to *
File size: 12.1 KB
Line 
1/* This file is derived from the GAS 2.1.4 assembler control file.
2   The GAS product is under the GNU General Public License, version 2 or later.
3   As such, this file is also under that license.
4
5   If the file format changes in the COFF object, this file should be
6   subsequently updated to reflect the changes.
7
8   The actual loader module only uses a few of these structures. The full
9   set is documented here because I received the full set. If you wish
10   more information about COFF, then O'Reilly has a very excellent book.
11*/
12
13#define  E_SYMNMLEN  8   /* Number of characters in a symbol name         */
14#define  E_FILNMLEN 14   /* Number of characters in a file name           */
15#define  E_DIMNUM    4   /* Number of array dimensions in auxiliary entry */
16
17/*
18 * These defines are byte order independent. There is no alignment of fields
19 * permitted in the structures. Therefore they are declared as characters
20 * and the values loaded from the character positions. It also makes it
21 * nice to have it "endian" independent.
22 */
23 
24/* Load a short int from the following tables with little-endian formats */
25#define COFF_SHORT_L(ps) ((short)(((unsigned short)((unsigned char)ps[1])<<8)|\
26                                  ((unsigned short)((unsigned char)ps[0]))))
27
28/* Load a long int from the following tables with little-endian formats */
29#define COFF_LONG_L(ps) (((long)(((unsigned long)((unsigned char)ps[3])<<24) |\
30                                 ((unsigned long)((unsigned char)ps[2])<<16) |\
31                                 ((unsigned long)((unsigned char)ps[1])<<8)  |\
32                                 ((unsigned long)((unsigned char)ps[0])))))
33 
34/* Load a short int from the following tables with big-endian formats */
35#define COFF_SHORT_H(ps) ((short)(((unsigned short)((unsigned char)ps[0])<<8)|\
36                                  ((unsigned short)((unsigned char)ps[1]))))
37
38/* Load a long int from the following tables with big-endian formats */
39#define COFF_LONG_H(ps) (((long)(((unsigned long)((unsigned char)ps[0])<<24) |\
40                                 ((unsigned long)((unsigned char)ps[1])<<16) |\
41                                 ((unsigned long)((unsigned char)ps[2])<<8)  |\
42                                 ((unsigned long)((unsigned char)ps[3])))))
43
44/* These may be overridden later by brain dead implementations which generate
45   a big-endian header with little-endian data. In that case, generate a
46   replacement macro which tests a flag and uses either of the two above
47   as appropriate. */
48
49#define COFF_LONG(v)   COFF_LONG_L(v)
50#define COFF_SHORT(v)  COFF_SHORT_L(v)
51
52/*** coff information for Intel 386/486.  */
53
54/********************** FILE HEADER **********************/
55
56struct COFF_filehdr {
57        char f_magic[2];        /* magic number                 */
58        char f_nscns[2];        /* number of sections           */
59        char f_timdat[4];       /* time & date stamp            */
60        char f_symptr[4];       /* file pointer to symtab       */
61        char f_nsyms[4];        /* number of symtab entries     */
62        char f_opthdr[2];       /* sizeof(optional hdr)         */
63        char f_flags[2];        /* flags                        */
64};
65
66/*
67 *   Bits for f_flags:
68 *
69 *      F_RELFLG        relocation info stripped from file
70 *      F_EXEC          file is executable  (i.e. no unresolved external
71 *                      references)
72 *      F_LNNO          line numbers stripped from file
73 *      F_LSYMS         local symbols stripped from file
74 *      F_MINMAL        this is a minimal object file (".m") output of fextract
75 *      F_UPDATE        this is a fully bound update file, output of ogen
76 *      F_SWABD         this file has had its bytes swabbed (in names)
77 *      F_AR16WR        this file has the byte ordering of an AR16WR
78 *                      (e.g. 11/70) machine
79 *      F_AR32WR        this file has the byte ordering of an AR32WR machine
80 *                      (e.g. vax and iNTEL 386)
81 *      F_AR32W         this file has the byte ordering of an AR32W machine
82 *                      (e.g. 3b,maxi)
83 *      F_PATCH         file contains "patch" list in optional header
84 *      F_NODF          (minimal file only) no decision functions for
85 *                      replaced functions
86 */
87
88#define  COFF_F_RELFLG          0000001
89#define  COFF_F_EXEC            0000002
90#define  COFF_F_LNNO            0000004
91#define  COFF_F_LSYMS           0000010
92#define  COFF_F_MINMAL          0000020
93#define  COFF_F_UPDATE          0000040
94#define  COFF_F_SWABD           0000100
95#define  COFF_F_AR16WR          0000200
96#define  COFF_F_AR32WR          0000400
97#define  COFF_F_AR32W           0001000
98#define  COFF_F_PATCH           0002000
99#define  COFF_F_NODF            0002000
100
101#define COFF_I386MAGIC          0x14c   /* Linux's system    */
102
103#if 0   /* Perhaps, someday, these formats may be used.      */
104#define COFF_I386PTXMAGIC       0x154
105#define COFF_I386AIXMAGIC       0x175   /* IBM's AIX system  */
106#define COFF_I386BADMAG(x) ((COFF_SHORT((x).f_magic) != COFF_I386MAGIC) \
107                          && COFF_SHORT((x).f_magic) != COFF_I386PTXMAGIC \
108                          && COFF_SHORT((x).f_magic) != COFF_I386AIXMAGIC)
109#else
110#define COFF_I386BADMAG(x) (COFF_SHORT((x).f_magic) != COFF_I386MAGIC)
111#endif
112
113#define COFF_FILHDR     struct COFF_filehdr
114#define COFF_FILHSZ     sizeof(COFF_FILHDR)
115
116/********************** AOUT "OPTIONAL HEADER" **********************/
117
118/* Linux COFF must have this "optional" header. Standard COFF has no entry
119   location for the "entry" point. They normally would start with the first
120   location of the .text section. This is not a good idea for linux. So,
121   the use of this "optional" header is not optional. It is required.
122
123   Do not be tempted to assume that the size of the optional header is
124   a constant and simply index the next byte by the size of this structure.
125   Use the 'f_opthdr' field in the main coff header for the size of the
126   structure actually written to the file!!
127*/
128
129typedef struct 
130{
131  char  magic[2];               /* type of file                          */
132  char  vstamp[2];              /* version stamp                         */
133  char  tsize[4];               /* text size in bytes, padded to FW bdry */
134  char  dsize[4];               /* initialized   data "   "              */
135  char  bsize[4];               /* uninitialized data "   "              */
136  char  entry[4];               /* entry pt.                             */
137  char  text_start[4];          /* base of text used for this file       */
138  char  data_start[4];          /* base of data used for this file       */
139}
140COFF_AOUTHDR;
141
142#define COFF_AOUTSZ (sizeof(COFF_AOUTHDR))
143
144#define COFF_STMAGIC    0401
145#define COFF_OMAGIC     0404
146#define COFF_JMAGIC     0407    /* dirty text and data image, can't share  */
147#define COFF_DMAGIC     0410    /* dirty text segment, data aligned        */
148#define COFF_ZMAGIC     0413    /* The proper magic number for executables  */
149#define COFF_SHMAGIC    0443    /* shared library header                   */
150
151/********************** SECTION HEADER **********************/
152
153struct COFF_scnhdr {
154  char          s_name[8];      /* section name                     */
155  char          s_paddr[4];     /* physical address, aliased s_nlib */
156  char          s_vaddr[4];     /* virtual address                  */
157  char          s_size[4];      /* section size                     */
158  char          s_scnptr[4];    /* file ptr to raw data for section */
159  char          s_relptr[4];    /* file ptr to relocation           */
160  char          s_lnnoptr[4];   /* file ptr to line numbers         */
161  char          s_nreloc[2];    /* number of relocation entries     */
162  char          s_nlnno[2];     /* number of line number entries    */
163  char          s_flags[4];     /* flags                            */
164};
165
166#define COFF_SCNHDR     struct COFF_scnhdr
167#define COFF_SCNHSZ     sizeof(COFF_SCNHDR)
168
169/*
170 * names of "special" sections
171 */
172
173#define COFF_TEXT       ".text"
174#define COFF_DATA       ".data"
175#define COFF_BSS        ".bss"
176#define COFF_COMMENT    ".comment"
177#define COFF_LIB        ".lib"
178
179#define COFF_SECT_TEXT  0      /* Section for instruction code             */
180#define COFF_SECT_DATA  1      /* Section for initialized globals          */
181#define COFF_SECT_BSS   2      /* Section for un-initialized globals       */
182#define COFF_SECT_REQD  3      /* Minimum number of sections for good file */
183
184#define COFF_STYP_REG     0x00 /* regular segment                          */
185#define COFF_STYP_DSECT   0x01 /* dummy segment                            */
186#define COFF_STYP_NOLOAD  0x02 /* no-load segment                          */
187#define COFF_STYP_GROUP   0x04 /* group segment                            */
188#define COFF_STYP_PAD     0x08 /* .pad segment                             */
189#define COFF_STYP_COPY    0x10 /* copy section                             */
190#define COFF_STYP_TEXT    0x20 /* .text segment                            */
191#define COFF_STYP_DATA    0x40 /* .data segment                            */
192#define COFF_STYP_BSS     0x80 /* .bss segment                             */
193#define COFF_STYP_INFO   0x200 /* .comment section                         */
194#define COFF_STYP_OVER   0x400 /* overlay section                          */
195#define COFF_STYP_LIB    0x800 /* library section                          */
196
197/*
198 * Shared libraries have the following section header in the data field for
199 * each library.
200 */
201
202struct COFF_slib {
203  char          sl_entsz[4];    /* Size of this entry               */
204  char          sl_pathndx[4];  /* size of the header field         */
205};
206
207#define COFF_SLIBHD     struct COFF_slib
208#define COFF_SLIBSZ     sizeof(COFF_SLIBHD)
209
210/********************** LINE NUMBERS **********************/
211
212/* 1 line number entry for every "breakpointable" source line in a section.
213 * Line numbers are grouped on a per function basis; first entry in a function
214 * grouping will have l_lnno = 0 and in place of physical address will be the
215 * symbol table index of the function name.
216 */
217
218struct COFF_lineno {
219  union {
220    char l_symndx[4];   /* function name symbol index, iff l_lnno == 0*/
221    char l_paddr[4];    /* (physical) address of line number    */
222  } l_addr;
223  char l_lnno[2];       /* line number          */
224};
225
226#define COFF_LINENO     struct COFF_lineno
227#define COFF_LINESZ     6
228
229/********************** SYMBOLS **********************/
230
231#define COFF_E_SYMNMLEN  8      /* # characters in a short symbol name  */
232#define COFF_E_FILNMLEN 14      /* # characters in a file name          */
233#define COFF_E_DIMNUM    4      /* # array dimensions in auxiliary entry */
234
235/*
236 *  All symbols and sections have the following definition
237 */
238
239struct COFF_syment
240{
241  union {
242    char e_name[E_SYMNMLEN];    /* Symbol name (first 8 characters) */
243    struct {
244      char e_zeroes[4];         /* Leading zeros */
245      char e_offset[4];         /* Offset if this is a header section */
246    } e;
247  } e;
248
249  char e_value[4];              /* Value (address) of the segment */
250  char e_scnum[2];              /* Section number */
251  char e_type[2];               /* Type of section */
252  char e_sclass[1];             /* Loader class */
253  char e_numaux[1];             /* Number of auxiliary entries which follow */
254};
255
256#define COFF_N_BTMASK   (0xf)   /* Mask for important class bits */
257#define COFF_N_TMASK    (0x30)  /* Mask for important type bits  */
258#define COFF_N_BTSHFT   (4)     /* # bits to shift class field   */
259#define COFF_N_TSHIFT   (2)     /* # bits to shift type field    */
260
261/*
262 *  Auxiliary entries because the main table is too limiting.
263 */
264 
265union COFF_auxent {
266
267/*
268 *  Debugger information
269 */
270
271  struct {
272    char x_tagndx[4];           /* str, un, or enum tag indx */
273    union {
274      struct {
275        char  x_lnno[2];        /* declaration line number */
276        char  x_size[2];        /* str/union/array size */
277      } x_lnsz;
278      char x_fsize[4];          /* size of function */
279    } x_misc;
280
281    union {
282      struct {                  /* if ISFCN, tag, or .bb */
283        char x_lnnoptr[4];      /* ptr to fcn line # */
284        char x_endndx[4];       /* entry ndx past block end */
285      } x_fcn;
286
287      struct {                  /* if ISARY, up to 4 dimen. */
288        char x_dimen[E_DIMNUM][2];
289      } x_ary;
290    } x_fcnary;
291
292    char x_tvndx[2];    /* tv index */
293  } x_sym;
294
295/*
296 *   Source file names (debugger information)
297 */
298
299  union {
300    char x_fname[E_FILNMLEN];
301    struct {
302      char x_zeroes[4];
303      char x_offset[4];
304    } x_n;
305  } x_file;
306
307/*
308 *   Section information
309 */
310
311  struct {
312    char x_scnlen[4];   /* section length */
313    char x_nreloc[2];   /* # relocation entries */
314    char x_nlinno[2];   /* # line numbers */
315  } x_scn;
316
317/*
318 *   Transfer vector (branch table)
319 */
320 
321  struct {
322    char x_tvfill[4];   /* tv fill value */
323    char x_tvlen[2];    /* length of .tv */
324    char x_tvran[2][2]; /* tv range */
325  } x_tv;               /* info about .tv section (in auxent of symbol .tv)) */
326};
327
328#define COFF_SYMENT     struct COFF_syment
329#define COFF_SYMESZ     18     
330#define COFF_AUXENT     union COFF_auxent
331#define COFF_AUXESZ     18
332
333#define COFF_ETEXT      "etext"
334
335/********************** RELOCATION DIRECTIVES **********************/
336
337struct COFF_reloc {
338  char r_vaddr[4];        /* Virtual address of item    */
339  char r_symndx[4];       /* Symbol index in the symtab */
340  char r_type[2];         /* Relocation type            */
341};
342
343#define COFF_RELOC struct COFF_reloc
344#define COFF_RELSZ 10
345
346#define COFF_DEF_DATA_SECTION_ALIGNMENT  4
347#define COFF_DEF_BSS_SECTION_ALIGNMENT   4
348#define COFF_DEF_TEXT_SECTION_ALIGNMENT  4
349
350/* For new sections we haven't heard of before */
351#define COFF_DEF_SECTION_ALIGNMENT       4
Note: See TracBrowser for help on using the repository browser.