ld/scripttempl/elf.sc

   1 #
   2 # Unusual variables checked by this code:
   3 #       NOP - two byte opcode for no-op (defaults to 0)
   4 #       DATA_ADDR - if end-of-text-plus-one-page isn't right for data start
   5 #       INITIAL_READONLY_SECTIONS - at start of text segment
   6 #       OTHER_READONLY_SECTIONS - other than .text .init .rodata ...
   7 #               (e.g., .PARISC.milli)
   8 #       OTHER_TEXT_SECTIONS - these get put in .text when relocating
   9 #       OTHER_READWRITE_SECTIONS - other than .data .bss .ctors .sdata ...
  10 #               (e.g., .PARISC.global)
  11 #       OTHER_BSS_SECTIONS - other than .bss .sbss ...
  12 #       OTHER_SECTIONS - at the end
  13 #       EXECUTABLE_SYMBOLS - symbols that must be defined for an
  14 #               executable (e.g., _DYNAMIC_LINK)
  15 #       TEXT_START_SYMBOLS - symbols that appear at the start of the
  16 #               .text section.
  17 #       DATA_START_SYMBOLS - symbols that appear at the start of the
  18 #               .data section.
  19 #       OTHER_GOT_SYMBOLS - symbols defined just before .got.
  20 #       OTHER_GOT_SECTIONS - sections just after .got and .sdata.
  21 #       OTHER_BSS_SYMBOLS - symbols that appear at the start of the
  22 #               .bss section besides __bss_start.
  23 #       DATA_PLT - .plt should be in data segment, not text segment.
  24 #       BSS_PLT - .plt should be in bss segment
  25 #       TEXT_DYNAMIC - .dynamic in text segment, not data segment.
  26 #       EMBEDDED - whether this is for an embedded system.
  27 #       SHLIB_TEXT_START_ADDR - if set, add to SIZEOF_HEADERS to set
  28 #               start address of shared library.
  29 #       INPUT_FILES - INPUT command of files to always include
  30 #       WRITABLE_RODATA - if set, the .rodata section should be writable
  31 #       INIT_START, INIT_END -  statements just before and just after
  32 #       combination of .init sections.
  33 #       FINI_START, FINI_END - statements just before and just after
  34 #       combination of .fini sections.
  35 #
  36 # When adding sections, do note that the names of some sections are used
  37 # when specifying the start address of the next.
  38 #
  39
  40 #  Many sections come in three flavours.  There is the 'real' section,
  41 #  like ".data".  Then there are the per-procedure or per-variable
  42 #  sections, generated by -ffunction-sections and -fdata-sections in GCC,
  43 #  and useful for --gc-sections, which for a variable "foo" might be
  44 #  ".data.foo".  Then there are the linkonce sections, for which the linker
  45 #  eliminates duplicates, which are named like ".gnu.linkonce.d.foo".
  46 #  The exact correspondences are:
  47 #
  48 #  Section      Linkonce section
  49 #  .text        .gnu.linkonce.t.foo
  50 #  .rodata      .gnu.linkonce.r.foo
  51 #  .data        .gnu.linkonce.d.foo
  52 #  .bss         .gnu.linkonce.b.foo
  53 #  .sdata       .gnu.linkonce.s.foo
  54 #  .sbss        .gnu.linkonce.sb.foo
  55 #  .sdata2      .gnu.linkonce.s2.foo
  56 #  .sbss2       .gnu.linkonce.sb2.foo
  57 #
  58 #  Each of these can also have corresponding .rel.* and .rela.* sections.
  59
  60 test -z "$ENTRY" && ENTRY=_start
  61 test -z "${BIG_OUTPUT_FORMAT}" && BIG_OUTPUT_FORMAT=${OUTPUT_FORMAT}
  62 test -z "${LITTLE_OUTPUT_FORMAT}" && LITTLE_OUTPUT_FORMAT=${OUTPUT_FORMAT}
  63 if [ -z "$MACHINE" ]; then OUTPUT_ARCH=${ARCH}; else OUTPUT_ARCH=${ARCH}:${MACHINE}; fi
  64 test -z "${ELFSIZE}" && ELFSIZE=32
  65 test -z "${ALIGNMENT}" && ALIGNMENT="${ELFSIZE} / 8"
  66 test "$LD_FLAG" = "N" && DATA_ADDR=.
  67 INTERP=".interp   ${RELOCATING-0} : { *(.interp)        }"
  68 PLT=".plt    ${RELOCATING-0} : { *(.plt)        }"
  69 DYNAMIC=".dynamic     ${RELOCATING-0} : { *(.dynamic) }"
  70 RODATA=".rodata ${RELOCATING-0} : { *(.rodata) ${RELOCATING+*(.rodata.*)} ${RELOCATING+*(.gnu.linkonce.r.*)} }"
  71 SBSS2=".sbss2 ${RELOCATING-0} : { *(.sbss2) ${RELOCATING+*(.sbss2.*)} ${RELOCATING+*(.gnu.linkonce.sb2.*)} }"
  72 SDATA2=".sdata2 ${RELOCATING-0} : { *(.sdata2) ${RELOCATING+*(.sdata2.*)} ${RELOCATING+*(.gnu.linkonce.s2.*)} }"
  73 CTOR=".ctors ${CONSTRUCTING-0} :
  74   {
  75     ${CONSTRUCTING+${CTOR_START}}
  76     /* gcc uses crtbegin.o to find the start of
  77        the constructors, so we make sure it is
  78        first.  Because this is a wildcard, it
  79        doesn't matter if the user does not
  80        actually link against crtbegin.o; the
  81        linker won't look for a file to match a
  82        wildcard.  The wildcard also means that it
  83        doesn't matter which directory crtbegin.o
  84        is in.  */
  85
  86     KEEP (*crtbegin.o(.ctors))
  87
  88     /* We don't want to include the .ctor section from
  89        from the crtend.o file until after the sorted ctors.
  90        The .ctor section from the crtend file contains the
  91        end of ctors marker and it must be last */
  92
  93     KEEP (*(EXCLUDE_FILE (*crtend.o $OTHER_EXCLUDE_FILES) .ctors))
  94     KEEP (*(SORT(.ctors.*)))
  95     KEEP (*(.ctors))
  96     ${CONSTRUCTING+${CTOR_END}}
  97   }"
  98
  99 DTOR=" .dtors       ${CONSTRUCTING-0} :
 100   {
 101     ${CONSTRUCTING+${DTOR_START}}
 102     KEEP (*crtbegin.o(.dtors))
 103     KEEP (*(EXCLUDE_FILE (*crtend.o $OTHER_EXCLUDE_FILES) .dtors))
 104     KEEP (*(SORT(.dtors.*)))
 105     KEEP (*(.dtors))
 106     ${CONSTRUCTING+${DTOR_END}}
 107   }"
 108
 109 # if this is for an embedded system, don't add SIZEOF_HEADERS.
 110 if [ -z "$EMBEDDED" ]; then
 111    test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR} + SIZEOF_HEADERS"
 112 else
 113    test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR}"
 114 fi
 115
 116 cat <<EOF
 117 OUTPUT_FORMAT("${OUTPUT_FORMAT}", "${BIG_OUTPUT_FORMAT}",
 118               "${LITTLE_OUTPUT_FORMAT}")
 119 OUTPUT_ARCH(${OUTPUT_ARCH})
 120 ENTRY(${ENTRY})
 121
 122 ${RELOCATING+${LIB_SEARCH_DIRS}}
 123 ${RELOCATING+/* Do we need any of these for elf?
 124    __DYNAMIC = 0; ${STACKZERO+${STACKZERO}} ${SHLIB_PATH+${SHLIB_PATH}}  */}
 125 ${RELOCATING+${EXECUTABLE_SYMBOLS}}
 126 ${RELOCATING+${INPUT_FILES}}
 127 ${RELOCATING- /* For some reason, the Solaris linker makes bad executables
 128   if gld -r is used and the intermediate file has sections starting
 129   at non-zero addresses.  Could be a Solaris ld bug, could be a GNU ld
 130   bug.  But for now assigning the zero vmas works.  */}
 131
 132 SECTIONS
 133 {
 134   /* Read-only sections, merged into text segment: */
 135   ${CREATE_SHLIB-${RELOCATING+. = ${TEXT_BASE_ADDRESS};}}
 136   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_TEXT_START_ADDR:-0} + SIZEOF_HEADERS;}}
 137   ${CREATE_SHLIB-${INTERP}}
 138   ${INITIAL_READONLY_SECTIONS}
 139   ${TEXT_DYNAMIC+${DYNAMIC}}
 140   .hash        ${RELOCATING-0} : { *(.hash)             }
 141   .dynsym      ${RELOCATING-0} : { *(.dynsym)           }
 142   .dynstr      ${RELOCATING-0} : { *(.dynstr)           }
 143   .gnu.version ${RELOCATING-0} : { *(.gnu.version)      }
 144   .gnu.version_d ${RELOCATING-0} : { *(.gnu.version_d)  }
 145   .gnu.version_r ${RELOCATING-0} : { *(.gnu.version_r)  }
 146
 147   .rel.init    ${RELOCATING-0} : { *(.rel.init) }
 148   .rela.init   ${RELOCATING-0} : { *(.rela.init)        }
 149   .rel.text    ${RELOCATING-0} :
 150     {
 151       *(.rel.text)
 152       ${RELOCATING+*(.rel.text.*)}
 153       ${RELOCATING+*(.rel.gnu.linkonce.t.*)}
 154     }
 155   .rela.text   ${RELOCATING-0} :
 156     {
 157       *(.rela.text)
 158       ${RELOCATING+*(.rela.text.*)}
 159       ${RELOCATING+*(.rela.gnu.linkonce.t.*)}
 160     }
 161   .rel.fini    ${RELOCATING-0} : { *(.rel.fini) }
 162   .rela.fini   ${RELOCATING-0} : { *(.rela.fini)        }
 163   .rel.rodata  ${RELOCATING-0} :
 164     {
 165       *(.rel.rodata)
 166       ${RELOCATING+*(.rel.rodata.*)}
 167       ${RELOCATING+*(.rel.gnu.linkonce.r.*)}
 168     }
 169   .rela.rodata ${RELOCATING-0} :
 170     {
 171       *(.rela.rodata)
 172       ${RELOCATING+*(.rela.rodata.*)}
 173       ${RELOCATING+*(.rela.gnu.linkonce.r.*)}
 174     }
 175   ${OTHER_READONLY_RELOC_SECTIONS}
 176   .rel.data    ${RELOCATING-0} :
 177     {
 178       *(.rel.data)
 179       ${RELOCATING+*(.rel.data.*)}
 180       ${RELOCATING+*(.rel.gnu.linkonce.d.*)}
 181     }
 182   .rela.data   ${RELOCATING-0} :
 183     {
 184       *(.rela.data)
 185       ${RELOCATING+*(.rela.data.*)}
 186       ${RELOCATING+*(.rela.gnu.linkonce.d.*)}
 187     }
 188   .rel.ctors   ${RELOCATING-0} : { *(.rel.ctors)        }
 189   .rela.ctors  ${RELOCATING-0} : { *(.rela.ctors)       }
 190   .rel.dtors   ${RELOCATING-0} : { *(.rel.dtors)        }
 191   .rela.dtors  ${RELOCATING-0} : { *(.rela.dtors)       }
 192   .rel.got     ${RELOCATING-0} : { *(.rel.got)          }
 193   .rela.got    ${RELOCATING-0} : { *(.rela.got)         }
 194   ${OTHER_GOT_RELOC_SECTIONS}
 195   .rel.sdata   ${RELOCATING-0} :
 196     {
 197       *(.rel.sdata)
 198       ${RELOCATING+*(.rel.sdata.*)}
 199       ${RELOCATING+*(.rel.gnu.linkonce.s.*)}
 200     }
 201   .rela.sdata   ${RELOCATING-0} :
 202     {
 203       *(.rela.sdata)
 204       ${RELOCATING+*(.rela.sdata.*)}
 205       ${RELOCATING+*(.rela.gnu.linkonce.s.*)}
 206     }
 207   .rel.sbss    ${RELOCATING-0} :
 208     {
 209       *(.rel.sbss)
 210       ${RELOCATING+*(.rel.sbss.*)}
 211       ${RELOCATING+*(.rel.gnu.linkonce.sb.*)}
 212     }
 213   .rela.sbss   ${RELOCATING-0} :
 214     {
 215       *(.rela.sbss)
 216       ${RELOCATING+*(.rela.sbss.*)}
 217       ${RELOCATING+*(.rel.gnu.linkonce.sb.*)}
 218     }
 219   .rel.sdata2  ${RELOCATING-0} :
 220     {
 221       *(.rel.sdata2)
 222       ${RELOCATING+*(.rel.sdata2.*)}
 223       ${RELOCATING+*(.rel.gnu.linkonce.s2.*)}
 224     }
 225   .rela.sdata2 ${RELOCATING-0} :
 226     {
 227       *(.rela.sdata2)
 228       ${RELOCATING+*(.rela.sdata2.*)}
 229       ${RELOCATING+*(.rela.gnu.linkonce.s2.*)}
 230     }
 231   .rel.sbss2   ${RELOCATING-0} :
 232     {
 233       *(.rel.sbss2)
 234       ${RELOCATING+*(.rel.sbss2.*)}
 235       ${RELOCATING+*(.rel.gnu.linkonce.sb2.*)}
 236     }
 237   .rela.sbss2  ${RELOCATING-0} :
 238     {
 239       *(.rela.sbss2)
 240       ${RELOCATING+*(.rela.sbss2.*)}
 241       ${RELOCATING+*(.rela.gnu.linkonce.sb2.*)}
 242     }
 243   .rel.bss     ${RELOCATING-0} :
 244     {
 245       *(.rel.bss)
 246       ${RELOCATING+*(.rel.bss.*)}
 247       ${RELOCATING+*(.rel.gnu.linkonce.b.*)}
 248     }
 249   .rela.bss    ${RELOCATING-0} :
 250     {
 251       *(.rela.bss)
 252       ${RELOCATING+*(.rela.bss.*)}
 253       ${RELOCATING+*(.rela.gnu.linkonce.b.*)}
 254     }
 255   .rel.plt     ${RELOCATING-0} : { *(.rel.plt)          }
 256   .rela.plt    ${RELOCATING-0} : { *(.rela.plt)         }
 257   ${OTHER_PLT_RELOC_SECTIONS}
 258
 259   .init        ${RELOCATING-0} :
 260   {
 261     ${RELOCATING+${INIT_START}}
 262     KEEP (*(.init))
 263     ${RELOCATING+${INIT_END}}
 264   } =${NOP-0}
 265
 266   ${DATA_PLT-${BSS_PLT-${PLT}}}
 267   .text    ${RELOCATING-0} :
 268   {
 269     ${RELOCATING+${TEXT_START_SYMBOLS}}
 270     *(.text)
 271     ${RELOCATING+*(.text.*)}
 272     *(.stub)
 273     /* .gnu.warning sections are handled specially by elf32.em.  */
 274     *(.gnu.warning)
 275     ${RELOCATING+*(.gnu.linkonce.t.*)}
 276     ${RELOCATING+${OTHER_TEXT_SECTIONS}}
 277   } =${NOP-0}
 278   .fini    ${RELOCATING-0} :
 279   {
 280     ${RELOCATING+${FINI_START}}
 281     KEEP (*(.fini))
 282     ${RELOCATING+${FINI_END}}
 283   } =${NOP-0}
 284   ${RELOCATING+PROVIDE (__etext = .);}
 285   ${RELOCATING+PROVIDE (_etext = .);}
 286   ${RELOCATING+PROVIDE (etext = .);}
 287   ${WRITABLE_RODATA-${RODATA}}
 288   .rodata1 ${RELOCATING-0} : { *(.rodata1) }
 289   ${CREATE_SHLIB-${SDATA2}}
 290   ${CREATE_SHLIB-${SBSS2}}
 291   ${RELOCATING+${OTHER_READONLY_SECTIONS}}
 292
 293   /* Adjust the address for the data segment.  We want to adjust up to
 294      the same address within the page on the next page up.  */
 295   ${CREATE_SHLIB-${RELOCATING+. = ${DATA_ADDR-ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))};}}
 296   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_DATA_ADDR-ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))};}}
 297
 298   .data  ${RELOCATING-0} :
 299   {
 300     ${RELOCATING+${DATA_START_SYMBOLS}}
 301     *(.data)
 302     ${RELOCATING+*(.data.*)}
 303     ${RELOCATING+*(.gnu.linkonce.d.*)}
 304     ${CONSTRUCTING+SORT(CONSTRUCTORS)}
 305   }
 306   .data1 ${RELOCATING-0} : { *(.data1) }
 307   .eh_frame : { KEEP (*(.eh_frame)) }
 308   .gcc_except_table : { *(.gcc_except_table) }
 309   ${WRITABLE_RODATA+${RODATA}}
 310   ${RELOCATING+${OTHER_READWRITE_SECTIONS}}
 311   ${RELOCATING+${CTOR}}
 312   ${RELOCATING+${DTOR}}
 313   ${DATA_PLT+${PLT}}
 314   ${RELOCATING+${OTHER_GOT_SYMBOLS}}
 315   .got          ${RELOCATING-0} : { *(.got.plt) *(.got) }
 316   ${CREATE_SHLIB+${SDATA2}}
 317   ${CREATE_SHLIB+${SBSS2}}
 318   ${TEXT_DYNAMIC-${DYNAMIC}}
 319   /* We want the small data sections together, so single-instruction offsets
 320      can access them all, and initialized data all before uninitialized, so
 321      we can shorten the on-disk segment size.  */
 322   .sdata   ${RELOCATING-0} :
 323   {
 324     ${RELOCATING+${SDATA_START_SYMBOLS}}
 325     *(.sdata)
 326     ${RELOCATING+*(.sdata.*)}
 327     ${RELOCATING+*(.gnu.linkonce.s.*)}
 328   }
 329   ${RELOCATING+${OTHER_GOT_SECTIONS}}
 330   ${RELOCATING+_edata = .;}
 331   ${RELOCATING+PROVIDE (edata = .);}
 332   ${RELOCATING+__bss_start = .;}
 333   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
 334   .sbss    ${RELOCATING-0} :
 335   {
 336     ${RELOCATING+PROVIDE (__sbss_start = .);}
 337     ${RELOCATING+PROVIDE (___sbss_start = .);}
 338     *(.dynsbss)
 339     *(.sbss)
 340     ${RELOCATING+*(.sbss.*)}
 341     ${RELOCATING+*(.gnu.linkonce.sb.*)}
 342     *(.scommon)
 343     ${RELOCATING+PROVIDE (__sbss_end = .);}
 344     ${RELOCATING+PROVIDE (___sbss_end = .);}
 345   }
 346   ${BSS_PLT+${PLT}}
 347   .bss     ${RELOCATING-0} :
 348   {
 349    *(.dynbss)
 350    *(.bss)
 351    ${RELOCATING+*(.bss.*)}
 352    ${RELOCATING+*(.gnu.linkonce.b.*)}
 353    *(COMMON)
 354    /* Align here to ensure that the .bss section occupies space up to
 355       _end.  Align after .bss to ensure correct alignment even if the
 356       .bss section disappears because there are no input sections.  */
 357    ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 358   }
 359   ${RELOCATING+${OTHER_BSS_SECTIONS}}
 360   ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 361   ${RELOCATING+_end = .;}
 362   ${RELOCATING+${OTHER_BSS_END_SYMBOLS}}
 363   ${RELOCATING+PROVIDE (end = .);}
 364
 365   /* Stabs debugging sections.  */
 366   .stab 0 : { *(.stab) }
 367   .stabstr 0 : { *(.stabstr) }
 368   .stab.excl 0 : { *(.stab.excl) }
 369   .stab.exclstr 0 : { *(.stab.exclstr) }
 370   .stab.index 0 : { *(.stab.index) }
 371   .stab.indexstr 0 : { *(.stab.indexstr) }
 372
 373   .comment 0 : { *(.comment) }
 374
 375   /* DWARF debug sections.
 376      Symbols in the DWARF debugging sections are relative to the beginning
 377      of the section so we begin them at 0.  */
 378
 379   /* DWARF 1 */
 380   .debug          0 : { *(.debug) }
 381   .line           0 : { *(.line) }
 382
 383   /* GNU DWARF 1 extensions */
 384   .debug_srcinfo  0 : { *(.debug_srcinfo) }
 385   .debug_sfnames  0 : { *(.debug_sfnames) }
 386
 387   /* DWARF 1.1 and DWARF 2 */
 388   .debug_aranges  0 : { *(.debug_aranges) }
 389   .debug_pubnames 0 : { *(.debug_pubnames) }
 390
 391   /* DWARF 2 */
 392   .debug_info     0 : { *(.debug_info) *(.gnu.linkonce.wi.*) }
 393   .debug_abbrev   0 : { *(.debug_abbrev) }
 394   .debug_line     0 : { *(.debug_line) }
 395   .debug_frame    0 : { *(.debug_frame) }
 396   .debug_str      0 : { *(.debug_str) }
 397   .debug_loc      0 : { *(.debug_loc) }
 398   .debug_macinfo  0 : { *(.debug_macinfo) }
 399
 400   /* SGI/MIPS DWARF 2 extensions */
 401   .debug_weaknames 0 : { *(.debug_weaknames) }
 402   .debug_funcnames 0 : { *(.debug_funcnames) }
 403   .debug_typenames 0 : { *(.debug_typenames) }
 404   .debug_varnames  0 : { *(.debug_varnames) }
 405
 406   ${RELOCATING+${OTHER_RELOCATING_SECTIONS}}
 407
 408   /* These must appear regardless of ${RELOCATING}.  */
 409   ${OTHER_SECTIONS}
 410 }
 411 EOF