coff.h
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上传日期:2013-04-10
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- /* This file is derived from the GAS 2.1.4 assembler control file.
- The GAS product is under the GNU General Public License, version 2 or later.
- As such, this file is also under that license.
- If the file format changes in the COFF object, this file should be
- subsequently updated to reflect the changes.
- The actual loader module only uses a few of these structures. The full
- set is documented here because I received the full set. If you wish
- more information about COFF, then O'Reilly has a very excellent book.
- */
- #define E_SYMNMLEN 8 /* Number of characters in a symbol name */
- #define E_FILNMLEN 14 /* Number of characters in a file name */
- #define E_DIMNUM 4 /* Number of array dimensions in auxiliary entry */
- /*
- * These defines are byte order independent. There is no alignment of fields
- * permitted in the structures. Therefore they are declared as characters
- * and the values loaded from the character positions. It also makes it
- * nice to have it "endian" independent.
- */
-
- /* Load a short int from the following tables with little-endian formats */
- #define COFF_SHORT_L(ps) ((short)(((unsigned short)((unsigned char)ps[1])<<8)|
- ((unsigned short)((unsigned char)ps[0]))))
- /* Load a long int from the following tables with little-endian formats */
- #define COFF_LONG_L(ps) (((long)(((unsigned long)((unsigned char)ps[3])<<24) |
- ((unsigned long)((unsigned char)ps[2])<<16) |
- ((unsigned long)((unsigned char)ps[1])<<8) |
- ((unsigned long)((unsigned char)ps[0])))))
-
- /* Load a short int from the following tables with big-endian formats */
- #define COFF_SHORT_H(ps) ((short)(((unsigned short)((unsigned char)ps[0])<<8)|
- ((unsigned short)((unsigned char)ps[1]))))
- /* Load a long int from the following tables with big-endian formats */
- #define COFF_LONG_H(ps) (((long)(((unsigned long)((unsigned char)ps[0])<<24) |
- ((unsigned long)((unsigned char)ps[1])<<16) |
- ((unsigned long)((unsigned char)ps[2])<<8) |
- ((unsigned long)((unsigned char)ps[3])))))
- /* These may be overridden later by brain dead implementations which generate
- a big-endian header with little-endian data. In that case, generate a
- replacement macro which tests a flag and uses either of the two above
- as appropriate. */
- #define COFF_LONG(v) COFF_LONG_L(v)
- #define COFF_SHORT(v) COFF_SHORT_L(v)
- /*** coff information for Intel 386/486. */
- /********************** FILE HEADER **********************/
- struct COFF_filehdr {
- char f_magic[2]; /* magic number */
- char f_nscns[2]; /* number of sections */
- char f_timdat[4]; /* time & date stamp */
- char f_symptr[4]; /* file pointer to symtab */
- char f_nsyms[4]; /* number of symtab entries */
- char f_opthdr[2]; /* sizeof(optional hdr) */
- char f_flags[2]; /* flags */
- };
- /*
- * Bits for f_flags:
- *
- * F_RELFLG relocation info stripped from file
- * F_EXEC file is executable (i.e. no unresolved external
- * references)
- * F_LNNO line numbers stripped from file
- * F_LSYMS local symbols stripped from file
- * F_MINMAL this is a minimal object file (".m") output of fextract
- * F_UPDATE this is a fully bound update file, output of ogen
- * F_SWABD this file has had its bytes swabbed (in names)
- * F_AR16WR this file has the byte ordering of an AR16WR
- * (e.g. 11/70) machine
- * F_AR32WR this file has the byte ordering of an AR32WR machine
- * (e.g. vax and iNTEL 386)
- * F_AR32W this file has the byte ordering of an AR32W machine
- * (e.g. 3b,maxi)
- * F_PATCH file contains "patch" list in optional header
- * F_NODF (minimal file only) no decision functions for
- * replaced functions
- */
- #define COFF_F_RELFLG 0000001
- #define COFF_F_EXEC 0000002
- #define COFF_F_LNNO 0000004
- #define COFF_F_LSYMS 0000010
- #define COFF_F_MINMAL 0000020
- #define COFF_F_UPDATE 0000040
- #define COFF_F_SWABD 0000100
- #define COFF_F_AR16WR 0000200
- #define COFF_F_AR32WR 0000400
- #define COFF_F_AR32W 0001000
- #define COFF_F_PATCH 0002000
- #define COFF_F_NODF 0002000
- #define COFF_I386MAGIC 0x14c /* Linux's system */
- #if 0 /* Perhaps, someday, these formats may be used. */
- #define COFF_I386PTXMAGIC 0x154
- #define COFF_I386AIXMAGIC 0x175 /* IBM's AIX system */
- #define COFF_I386BADMAG(x) ((COFF_SHORT((x).f_magic) != COFF_I386MAGIC)
- && COFF_SHORT((x).f_magic) != COFF_I386PTXMAGIC
- && COFF_SHORT((x).f_magic) != COFF_I386AIXMAGIC)
- #else
- #define COFF_I386BADMAG(x) (COFF_SHORT((x).f_magic) != COFF_I386MAGIC)
- #endif
- #define COFF_FILHDR struct COFF_filehdr
- #define COFF_FILHSZ sizeof(COFF_FILHDR)
- /********************** AOUT "OPTIONAL HEADER" **********************/
- /* Linux COFF must have this "optional" header. Standard COFF has no entry
- location for the "entry" point. They normally would start with the first
- location of the .text section. This is not a good idea for linux. So,
- the use of this "optional" header is not optional. It is required.
- Do not be tempted to assume that the size of the optional header is
- a constant and simply index the next byte by the size of this structure.
- Use the 'f_opthdr' field in the main coff header for the size of the
- structure actually written to the file!!
- */
- typedef struct
- {
- char magic[2]; /* type of file */
- char vstamp[2]; /* version stamp */
- char tsize[4]; /* text size in bytes, padded to FW bdry */
- char dsize[4]; /* initialized data " " */
- char bsize[4]; /* uninitialized data " " */
- char entry[4]; /* entry pt. */
- char text_start[4]; /* base of text used for this file */
- char data_start[4]; /* base of data used for this file */
- }
- COFF_AOUTHDR;
- #define COFF_AOUTSZ (sizeof(COFF_AOUTHDR))
- #define COFF_STMAGIC 0401
- #define COFF_OMAGIC 0404
- #define COFF_JMAGIC 0407 /* dirty text and data image, can't share */
- #define COFF_DMAGIC 0410 /* dirty text segment, data aligned */
- #define COFF_ZMAGIC 0413 /* The proper magic number for executables */
- #define COFF_SHMAGIC 0443 /* shared library header */
- /********************** SECTION HEADER **********************/
- struct COFF_scnhdr {
- char s_name[8]; /* section name */
- char s_paddr[4]; /* physical address, aliased s_nlib */
- char s_vaddr[4]; /* virtual address */
- char s_size[4]; /* section size */
- char s_scnptr[4]; /* file ptr to raw data for section */
- char s_relptr[4]; /* file ptr to relocation */
- char s_lnnoptr[4]; /* file ptr to line numbers */
- char s_nreloc[2]; /* number of relocation entries */
- char s_nlnno[2]; /* number of line number entries */
- char s_flags[4]; /* flags */
- };
- #define COFF_SCNHDR struct COFF_scnhdr
- #define COFF_SCNHSZ sizeof(COFF_SCNHDR)
- /*
- * names of "special" sections
- */
- #define COFF_TEXT ".text"
- #define COFF_DATA ".data"
- #define COFF_BSS ".bss"
- #define COFF_COMMENT ".comment"
- #define COFF_LIB ".lib"
- #define COFF_SECT_TEXT 0 /* Section for instruction code */
- #define COFF_SECT_DATA 1 /* Section for initialized globals */
- #define COFF_SECT_BSS 2 /* Section for un-initialized globals */
- #define COFF_SECT_REQD 3 /* Minimum number of sections for good file */
- #define COFF_STYP_REG 0x00 /* regular segment */
- #define COFF_STYP_DSECT 0x01 /* dummy segment */
- #define COFF_STYP_NOLOAD 0x02 /* no-load segment */
- #define COFF_STYP_GROUP 0x04 /* group segment */
- #define COFF_STYP_PAD 0x08 /* .pad segment */
- #define COFF_STYP_COPY 0x10 /* copy section */
- #define COFF_STYP_TEXT 0x20 /* .text segment */
- #define COFF_STYP_DATA 0x40 /* .data segment */
- #define COFF_STYP_BSS 0x80 /* .bss segment */
- #define COFF_STYP_INFO 0x200 /* .comment section */
- #define COFF_STYP_OVER 0x400 /* overlay section */
- #define COFF_STYP_LIB 0x800 /* library section */
- /*
- * Shared libraries have the following section header in the data field for
- * each library.
- */
- struct COFF_slib {
- char sl_entsz[4]; /* Size of this entry */
- char sl_pathndx[4]; /* size of the header field */
- };
- #define COFF_SLIBHD struct COFF_slib
- #define COFF_SLIBSZ sizeof(COFF_SLIBHD)
- /********************** LINE NUMBERS **********************/
- /* 1 line number entry for every "breakpointable" source line in a section.
- * Line numbers are grouped on a per function basis; first entry in a function
- * grouping will have l_lnno = 0 and in place of physical address will be the
- * symbol table index of the function name.
- */
- struct COFF_lineno {
- union {
- char l_symndx[4]; /* function name symbol index, iff l_lnno == 0*/
- char l_paddr[4]; /* (physical) address of line number */
- } l_addr;
- char l_lnno[2]; /* line number */
- };
- #define COFF_LINENO struct COFF_lineno
- #define COFF_LINESZ 6
- /********************** SYMBOLS **********************/
- #define COFF_E_SYMNMLEN 8 /* # characters in a short symbol name */
- #define COFF_E_FILNMLEN 14 /* # characters in a file name */
- #define COFF_E_DIMNUM 4 /* # array dimensions in auxiliary entry */
- /*
- * All symbols and sections have the following definition
- */
- struct COFF_syment
- {
- union {
- char e_name[E_SYMNMLEN]; /* Symbol name (first 8 characters) */
- struct {
- char e_zeroes[4]; /* Leading zeros */
- char e_offset[4]; /* Offset if this is a header section */
- } e;
- } e;
- char e_value[4]; /* Value (address) of the segment */
- char e_scnum[2]; /* Section number */
- char e_type[2]; /* Type of section */
- char e_sclass[1]; /* Loader class */
- char e_numaux[1]; /* Number of auxiliary entries which follow */
- };
- #define COFF_N_BTMASK (0xf) /* Mask for important class bits */
- #define COFF_N_TMASK (0x30) /* Mask for important type bits */
- #define COFF_N_BTSHFT (4) /* # bits to shift class field */
- #define COFF_N_TSHIFT (2) /* # bits to shift type field */
- /*
- * Auxiliary entries because the main table is too limiting.
- */
-
- union COFF_auxent {
- /*
- * Debugger information
- */
- struct {
- char x_tagndx[4]; /* str, un, or enum tag indx */
- union {
- struct {
- char x_lnno[2]; /* declaration line number */
- char x_size[2]; /* str/union/array size */
- } x_lnsz;
- char x_fsize[4]; /* size of function */
- } x_misc;
- union {
- struct { /* if ISFCN, tag, or .bb */
- char x_lnnoptr[4]; /* ptr to fcn line # */
- char x_endndx[4]; /* entry ndx past block end */
- } x_fcn;
- struct { /* if ISARY, up to 4 dimen. */
- char x_dimen[E_DIMNUM][2];
- } x_ary;
- } x_fcnary;
- char x_tvndx[2]; /* tv index */
- } x_sym;
- /*
- * Source file names (debugger information)
- */
- union {
- char x_fname[E_FILNMLEN];
- struct {
- char x_zeroes[4];
- char x_offset[4];
- } x_n;
- } x_file;
- /*
- * Section information
- */
- struct {
- char x_scnlen[4]; /* section length */
- char x_nreloc[2]; /* # relocation entries */
- char x_nlinno[2]; /* # line numbers */
- } x_scn;
- /*
- * Transfer vector (branch table)
- */
-
- struct {
- char x_tvfill[4]; /* tv fill value */
- char x_tvlen[2]; /* length of .tv */
- char x_tvran[2][2]; /* tv range */
- } x_tv; /* info about .tv section (in auxent of symbol .tv)) */
- };
- #define COFF_SYMENT struct COFF_syment
- #define COFF_SYMESZ 18
- #define COFF_AUXENT union COFF_auxent
- #define COFF_AUXESZ 18
- #define COFF_ETEXT "etext"
- /********************** RELOCATION DIRECTIVES **********************/
- struct COFF_reloc {
- char r_vaddr[4]; /* Virtual address of item */
- char r_symndx[4]; /* Symbol index in the symtab */
- char r_type[2]; /* Relocation type */
- };
- #define COFF_RELOC struct COFF_reloc
- #define COFF_RELSZ 10
- #define COFF_DEF_DATA_SECTION_ALIGNMENT 4
- #define COFF_DEF_BSS_SECTION_ALIGNMENT 4
- #define COFF_DEF_TEXT_SECTION_ALIGNMENT 4
- /* For new sections we haven't heard of before */
- #define COFF_DEF_SECTION_ALIGNMENT 4