include/coff/mips.h

   1 /* Rudimentary ECOFF support on MIPS machines.
   2    This lacks symbol information, normally provided on MIPS Unix systems
   3    in the files <sym.h> and <symconst.h>.  */
   4
   5 /********************** FILE HEADER **********************/
   6
   7 struct external_filehdr {
   8   unsigned char f_magic[2];     /* magic number                 */
   9   unsigned char f_nscns[2];     /* number of sections           */
  10   unsigned char f_timdat[4];    /* time & date stamp            */
  11   unsigned char f_symptr[4];    /* file pointer to symtab       */
  12   unsigned char f_nsyms[4];     /* number of symtab entries     */
  13   unsigned char f_opthdr[2];    /* sizeof(optional hdr)         */
  14   unsigned char f_flags[2];     /* flags                        */
  15 };
  16
  17
  18 /* Mips magic numbers used in filehdr.  MIPS_MAGIC_LITTLE is used on
  19    little endian machines.  MIPS_MAGIC_BIG is used on big endian
  20    machines.  Where is MIPS_MAGIC_1 from?  */
  21 #define MIPS_MAGIC_1 0x0180
  22 #define MIPS_MAGIC_LITTLE 0x0162
  23 #define MIPS_MAGIC_BIG 0x0160
  24
  25 #define ECOFFBADMAG(x) (((x).f_magic!=MIPS_MAGIC_1) && \
  26                         ((x).f_magic!=MIPS_MAGIC_LITTLE) &&\
  27                         ((x).f_magic!=MIPS_MAGIC_BIG))
  28
  29
  30 #define FILHDR  struct external_filehdr
  31 #define FILHSZ  20
  32
  33 /********************** AOUT "OPTIONAL HEADER" **********************/
  34
  35
  36 typedef struct external_aouthdr
  37 {
  38   unsigned char magic[2];       /* type of file                         */
  39   unsigned char vstamp[2];      /* version stamp                        */
  40   unsigned char tsize[4];       /* text size in bytes, padded to FW bdry*/
  41   unsigned char dsize[4];       /* initialized data "  "                */
  42   unsigned char bsize[4];       /* uninitialized data "   "             */
  43   unsigned char entry[4];       /* entry pt.                            */
  44   unsigned char text_start[4];  /* base of text used for this file */
  45   unsigned char data_start[4];  /* base of data used for this file */
  46   unsigned char bss_start[4];   /* base of bss used for this file */
  47   unsigned char gprmask[4];     /* ?? */
  48   unsigned char cprmask[4][4];  /* ?? */
  49   unsigned char gp_value[4];    /* value for gp register */
  50 } AOUTHDR;
  51
  52 /* compute size of a header */
  53
  54 #define AOUTSZ (sizeof(AOUTHDR))
  55
  56 #define OMAGIC          0407    /* not demand paged (ld -N).  */
  57 #define ZMAGIC          0413    /* demand load format, eg normal ld output */
  58
  59 /********************** SECTION HEADER **********************/
  60
  61 struct external_scnhdr {
  62   unsigned char s_name[8];      /* section name                 */
  63   unsigned char s_paddr[4];     /* physical address, aliased s_nlib */
  64   unsigned char s_vaddr[4];     /* virtual address              */
  65   unsigned char s_size[4];      /* section size                 */
  66   unsigned char s_scnptr[4];    /* file ptr to raw data for section */
  67   unsigned char s_relptr[4];    /* file ptr to relocation       */
  68   unsigned char s_lnnoptr[4];   /* file ptr to line numbers     */
  69   unsigned char s_nreloc[2];    /* number of relocation entries */
  70   unsigned char s_nlnno[2];     /* number of line number entries*/
  71   unsigned char s_flags[4];     /* flags                        */
  72 };
  73
  74 #define SCNHDR  struct external_scnhdr
  75 #define SCNHSZ  sizeof(SCNHDR)
  76
  77 /*
  78  * names of "special" sections
  79  */
  80 #define _TEXT   ".text"
  81 #define _DATA   ".data"
  82 #define _BSS    ".bss"
  83 #define _RDATA  ".rdata"
  84 #define _SDATA  ".sdata"
  85 #define _SBSS   ".sbss"
  86 #define _LIT4   ".lit4"
  87 #define _LIT8   ".lit8"
  88 #define _LIB    ".lib"
  89
  90 #define DEFAULT_DATA_SECTION_ALIGNMENT 4
  91 #define DEFAULT_BSS_SECTION_ALIGNMENT 4
  92 #define DEFAULT_TEXT_SECTION_ALIGNMENT 16
  93 /* For new sections we havn't heard of before */
  94 #define DEFAULT_SECTION_ALIGNMENT 4
  95
  96 /* MIPS ECOFF uses some additional section types.  */
  97 #define STYP_RDATA 0x100
  98 #define STYP_SDATA 0x200
  99 #define STYP_SBSS 0x400
 100 #define STYP_LIT8 0x8000000
 101 #define STYP_LIT4 0x10000000
 102
 103 /* I don't know when this is used.  */
 104 #define STYP_OTHER_LOAD 0x80000000
 105
 106 /********************** RELOCATION DIRECTIVES **********************/
 107
 108 struct external_reloc {
 109   unsigned char r_vaddr[4];
 110   unsigned char r_bits[4];
 111 };
 112
 113 #define RELOC struct external_reloc
 114 #define RELSZ 8
 115
 116 /* MIPS ECOFF uses a packed 8 byte format for relocs.  These constants
 117    are used to unpack the r_bits field.  */
 118
 119 #define RELOC_BITS0_SYMNDX_SH_LEFT_BIG          16
 120 #define RELOC_BITS0_SYMNDX_SH_LEFT_LITTLE       0
 121
 122 #define RELOC_BITS1_SYMNDX_SH_LEFT_BIG          8
 123 #define RELOC_BITS1_SYMNDX_SH_LEFT_LITTLE       8
 124
 125 #define RELOC_BITS2_SYMNDX_SH_LEFT_BIG          0
 126 #define RELOC_BITS2_SYMNDX_SH_LEFT_LITTLE       16
 127
 128 #define RELOC_BITS3_TYPE_BIG                    0x1E
 129 #define RELOC_BITS3_TYPE_SH_BIG                 1
 130 #define RELOC_BITS3_TYPE_LITTLE                 0x78
 131 #define RELOC_BITS3_TYPE_SH_LITTLE              3
 132
 133 #define RELOC_BITS3_EXTERN_BIG                  0x01
 134 #define RELOC_BITS3_EXTERN_LITTLE               0x80
 135
 136 /* We store the extern field in the r_offset field of a struct
 137    internal_reloc.  FIXME: Do this more sensibly.  */
 138 #define r_extern r_offset
 139
 140 /* If the extern bit is 1, then r_symndx is an index into the external
 141    symbol table.  If the extern bit is 0, then r_symndx indicates a
 142    section, and is one of the following values.  */
 143 #define RELOC_SECTION_TEXT      1
 144 #define RELOC_SECTION_RDATA     2
 145 #define RELOC_SECTION_DATA      3
 146 #define RELOC_SECTION_SDATA     4
 147 #define RELOC_SECTION_SBSS      5
 148 #define RELOC_SECTION_BSS       6
 149 #define RELOC_SECTION_INIT      7
 150 #define RELOC_SECTION_LIT8      8
 151 #define RELOC_SECTION_LIT4      9
 152
 153 /* The r_type field is one of the following values.  I don't know if
 154    any other values can appear.  These seem to be all that occur in
 155    the Ultrix 4.2 libraries.  */
 156 #define ECOFF_R_IGNORE  0
 157 #define ECOFF_R_REFHALF 1
 158 #define ECOFF_R_REFWORD 2
 159 #define ECOFF_R_JMPADDR 3
 160 #define ECOFF_R_REFHI   4
 161 #define ECOFF_R_REFLO   5
 162 #define ECOFF_R_GPREL   6
 163 #define ECOFF_R_LITERAL 7
 164
 165 /********************** STABS **********************/
 166
 167 /* gcc uses mips-tfile to output type information in special stabs
 168    entries.  These must match the corresponding definition in
 169    gcc/config/mips.h.  At some point, these should probably go into a
 170    shared include file, but currently gcc and gdb do not share any
 171    directories. */
 172 #define CODE_MASK 0x8F300
 173 #define MIPS_IS_STAB(sym) (((sym)->index & 0xFFF00) == CODE_MASK)
 174 #define MIPS_MARK_STAB(code) ((code)+CODE_MASK)
 175 #define MIPS_UNMARK_STAB(code) ((code)-CODE_MASK)
 176 #define STABS_SYMBOL "@stabs"
 177
 178 /********************** COFF **********************/
 179
 180 /* gcc also uses mips-tfile to output COFF debugging information.
 181    These are the values it uses when outputting the .type directive.
 182    These should also be in a shared include file.  */
 183 #define N_BTMASK        (017)
 184 #define N_TMASK         (060)
 185 #define N_BTSHFT        (4)
 186 #define N_TSHIFT        (2)