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 #       TEXT_DYNAMIC - .dynamic in text segment, not data segment.
  25 #       EMBEDDED - whether this is for an embedded system.
  26 #       SHLIB_TEXT_START_ADDR - if set, add to SIZEOF_HEADERS to set
  27 #               start address of shared library.
  28 #       INPUT_FILES - INPUT command of files to always include
  29 #       WRITABLE_RODATA - if set, the .rodata section should be writable
  30 #       INIT_START, INIT_END -  statements just before and just after
  31 #       combination of .init sections.
  32 #       FINI_START, FINI_END - statements just before and just after
  33 #       combination of .fini sections.
  34 #
  35 # When adding sections, do note that the names of some sections are used
  36 # when specifying the start address of the next.
  37 #
  38
  39 test -z "$ENTRY" && ENTRY=_start
  40 test -z "${BIG_OUTPUT_FORMAT}" && BIG_OUTPUT_FORMAT=${OUTPUT_FORMAT}
  41 test -z "${LITTLE_OUTPUT_FORMAT}" && LITTLE_OUTPUT_FORMAT=${OUTPUT_FORMAT}
  42 if [ -z "$MACHINE" ]; then OUTPUT_ARCH=${ARCH}; else OUTPUT_ARCH=${ARCH}:${MACHINE}; fi
  43 test -z "${ELFSIZE}" && ELFSIZE=32
  44 test -z "${ALIGNMENT}" && ALIGNMENT="${ELFSIZE} / 8"
  45 test "$LD_FLAG" = "N" && DATA_ADDR=.
  46 INTERP=".interp   ${RELOCATING-0} : { *(.interp)        }"
  47 PLT=".plt    ${RELOCATING-0} : { *(.plt)        }"
  48 DYNAMIC=".dynamic     ${RELOCATING-0} : { *(.dynamic) }"
  49 RODATA=".rodata ${RELOCATING-0} : { *(.rodata) ${RELOCATING+*(.rodata.*)} ${RELOCATING+*(.gnu.linkonce.r*)} }"
  50 CTOR=".ctors ${CONSTRUCTING-0} :
  51   {
  52     ${CONSTRUCTING+${CTOR_START}}
  53     /* gcc uses crtbegin.o to find the start of
  54        the constructors, so we make sure it is
  55        first.  Because this is a wildcard, it
  56        doesn't matter if the user does not
  57        actually link against crtbegin.o; the
  58        linker won't look for a file to match a
  59        wildcard.  The wildcard also means that it
  60        doesn't matter which directory crtbegin.o
  61        is in.  */
  62
  63     KEEP (*crtbegin.o(.ctors))
  64
  65     /* We don't want to include the .ctor section from
  66        from the crtend.o file until after the sorted ctors.
  67        The .ctor section from the crtend file contains the
  68        end of ctors marker and it must be last */
  69
  70     KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
  71     KEEP (*(SORT(.ctors.*)))
  72     KEEP (*(.ctors))
  73     ${CONSTRUCTING+${CTOR_END}}
  74   }"
  75
  76 DTOR=" .dtors       ${CONSTRUCTING-0} :
  77   {
  78     ${CONSTRUCTING+${DTOR_START}}
  79     KEEP (*crtbegin.o(.dtors))
  80     KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
  81     KEEP (*(SORT(.dtors.*)))
  82     KEEP (*(.dtors))
  83     ${CONSTRUCTING+${DTOR_END}}
  84   }"
  85
  86 # if this is for an embedded system, don't add SIZEOF_HEADERS.
  87 if [ -z "$EMBEDDED" ]; then
  88    test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR} + SIZEOF_HEADERS"
  89 else
  90    test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR}"
  91 fi
  92
  93 cat <<EOF
  94 OUTPUT_FORMAT("${OUTPUT_FORMAT}", "${BIG_OUTPUT_FORMAT}",
  95               "${LITTLE_OUTPUT_FORMAT}")
  96 OUTPUT_ARCH(${OUTPUT_ARCH})
  97 ENTRY(${ENTRY})
  98
  99 ${RELOCATING+${LIB_SEARCH_DIRS}}
 100 ${RELOCATING+/* Do we need any of these for elf?
 101    __DYNAMIC = 0; ${STACKZERO+${STACKZERO}} ${SHLIB_PATH+${SHLIB_PATH}}  */}
 102 ${RELOCATING+${EXECUTABLE_SYMBOLS}}
 103 ${RELOCATING+${INPUT_FILES}}
 104 ${RELOCATING- /* For some reason, the Solaris linker makes bad executables
 105   if gld -r is used and the intermediate file has sections starting
 106   at non-zero addresses.  Could be a Solaris ld bug, could be a GNU ld
 107   bug.  But for now assigning the zero vmas works.  */}
 108
 109 SECTIONS
 110 {
 111   /* Read-only sections, merged into text segment: */
 112   ${CREATE_SHLIB-${RELOCATING+. = ${TEXT_BASE_ADDRESS};}}
 113   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_TEXT_START_ADDR:-0} + SIZEOF_HEADERS;}}
 114   ${CREATE_SHLIB-${INTERP}}
 115   ${INITIAL_READONLY_SECTIONS}
 116   ${TEXT_DYNAMIC+${DYNAMIC}}
 117   .hash        ${RELOCATING-0} : { *(.hash)             }
 118   .dynsym      ${RELOCATING-0} : { *(.dynsym)           }
 119   .dynstr      ${RELOCATING-0} : { *(.dynstr)           }
 120   .gnu.version ${RELOCATING-0} : { *(.gnu.version)      }
 121   .gnu.version_d ${RELOCATING-0} : { *(.gnu.version_d)  }
 122   .gnu.version_r ${RELOCATING-0} : { *(.gnu.version_r)  }
 123
 124   .rel.init    ${RELOCATING-0} : { *(.rel.init) }
 125   .rela.init   ${RELOCATING-0} : { *(.rela.init)        }
 126   .rel.text    ${RELOCATING-0} :
 127     {
 128       *(.rel.text)
 129       ${RELOCATING+*(.rel.text.*)}
 130       ${RELOCATING+*(.rel.gnu.linkonce.t*)}
 131     }
 132   .rela.text   ${RELOCATING-0} :
 133     {
 134       *(.rela.text)
 135       ${RELOCATING+*(.rela.text.*)}
 136       ${RELOCATING+*(.rela.gnu.linkonce.t*)}
 137     }
 138   .rel.fini    ${RELOCATING-0} : { *(.rel.fini) }
 139   .rela.fini   ${RELOCATING-0} : { *(.rela.fini)        }
 140   .rel.rodata  ${RELOCATING-0} :
 141     {
 142       *(.rel.rodata)
 143       ${RELOCATING+*(.rel.rodata.*)}
 144       ${RELOCATING+*(.rel.gnu.linkonce.r*)}
 145     }
 146   .rela.rodata ${RELOCATING-0} :
 147     {
 148       *(.rela.rodata)
 149       ${RELOCATING+*(.rela.rodata.*)}
 150       ${RELOCATING+*(.rela.gnu.linkonce.r*)}
 151     }
 152   ${OTHER_READONLY_RELOC_SECTIONS}
 153   .rel.data    ${RELOCATING-0} :
 154     {
 155       *(.rel.data)
 156       ${RELOCATING+*(.rel.data.*)}
 157       ${RELOCATING+*(.rel.gnu.linkonce.d*)}
 158     }
 159   .rela.data   ${RELOCATING-0} :
 160     {
 161       *(.rela.data)
 162       ${RELOCATING+*(.rela.data.*)}
 163       ${RELOCATING+*(.rela.gnu.linkonce.d*)}
 164     }
 165   .rel.ctors   ${RELOCATING-0} : { *(.rel.ctors)        }
 166   .rela.ctors  ${RELOCATING-0} : { *(.rela.ctors)       }
 167   .rel.dtors   ${RELOCATING-0} : { *(.rel.dtors)        }
 168   .rela.dtors  ${RELOCATING-0} : { *(.rela.dtors)       }
 169   .rel.got     ${RELOCATING-0} : { *(.rel.got)          }
 170   .rela.got    ${RELOCATING-0} : { *(.rela.got)         }
 171   ${OTHER_GOT_RELOC_SECTIONS}
 172   .rel.bss     ${RELOCATING-0} : { *(.rel.bss)          }
 173   .rela.bss    ${RELOCATING-0} : { *(.rela.bss)         }
 174   .rel.plt     ${RELOCATING-0} : { *(.rel.plt)          }
 175   .rela.plt    ${RELOCATING-0} : { *(.rela.plt)         }
 176
 177   .init        ${RELOCATING-0} :
 178   {
 179     ${INIT_START}
 180     KEEP (*(.init))
 181     ${INIT_END}
 182   } =${NOP-0}
 183
 184   ${DATA_PLT-${PLT}}
 185   .text    ${RELOCATING-0} :
 186   {
 187     ${RELOCATING+${TEXT_START_SYMBOLS}}
 188     *(.text)
 189     ${RELOCATING+*(.text.*)}
 190     *(.stub)
 191     /* .gnu.warning sections are handled specially by elf32.em.  */
 192     *(.gnu.warning)
 193     ${RELOCATING+*(.gnu.linkonce.t*)}
 194     ${RELOCATING+${OTHER_TEXT_SECTIONS}}
 195   } =${NOP-0}
 196   ${RELOCATING+_etext = .;}
 197   ${RELOCATING+PROVIDE (etext = .);}
 198   .fini    ${RELOCATING-0} :
 199   {
 200     ${FINI_START}
 201     KEEP (*(.fini))
 202     ${FINI_END}
 203   } =${NOP-0}
 204   ${WRITABLE_RODATA-${RODATA}}
 205   .rodata1 ${RELOCATING-0} : { *(.rodata1) }
 206   ${RELOCATING+${OTHER_READONLY_SECTIONS}}
 207
 208   /* Adjust the address for the data segment.  We want to adjust up to
 209      the same address within the page on the next page up.  */
 210   ${CREATE_SHLIB-${RELOCATING+. = ${DATA_ADDR-ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))};}}
 211   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_DATA_ADDR-ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))};}}
 212
 213   .data  ${RELOCATING-0} :
 214   {
 215     ${RELOCATING+${DATA_START_SYMBOLS}}
 216     *(.data)
 217     ${RELOCATING+*(.data.*)}
 218     ${RELOCATING+*(.gnu.linkonce.d*)}
 219     ${CONSTRUCTING+SORT(CONSTRUCTORS)}
 220   }
 221   .data1 ${RELOCATING-0} : { *(.data1) }
 222   .eh_frame : { *(.eh_frame) }
 223   .gcc_except_table : { *(.gcc_except_table) }
 224   ${WRITABLE_RODATA+${RODATA}}
 225   ${RELOCATING+${OTHER_READWRITE_SECTIONS}}
 226   ${RELOCATING+${CTOR}}
 227   ${RELOCATING+${DTOR}}
 228   ${DATA_PLT+${PLT}}
 229   ${RELOCATING+${OTHER_GOT_SYMBOLS}}
 230   .got         ${RELOCATING-0} : { *(.got.plt) *(.got) }
 231   ${TEXT_DYNAMIC-${DYNAMIC}}
 232   /* We want the small data sections together, so single-instruction offsets
 233      can access them all, and initialized data all before uninitialized, so
 234      we can shorten the on-disk segment size.  */
 235   .sdata   ${RELOCATING-0} : { *(.sdata) *(.sdata.*) *(.gnu.linkonce.s.*) }
 236   ${RELOCATING+${OTHER_GOT_SECTIONS}}
 237   ${RELOCATING+_edata = .;}
 238   ${RELOCATING+PROVIDE (edata = .);}
 239   ${RELOCATING+__bss_start = .;}
 240   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
 241   .sbss    ${RELOCATING-0} :
 242   {
 243    *(.sbss) *(.scommon)
 244    ${RELOCATING+*(.sbss.*)}
 245   }
 246   .bss     ${RELOCATING-0} :
 247   {
 248    *(.dynbss)
 249    *(.bss)
 250    ${RELOCATING+*(.bss.*)}
 251    *(COMMON)
 252    /* Align here to ensure that the .bss section occupies space up to
 253       _end.  Align after .bss to ensure correct alignment even if the
 254       .bss section disappears because there are no input sections.  */
 255    ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 256   }
 257   ${RELOCATING+${OTHER_BSS_SECTIONS}}
 258   ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 259   ${RELOCATING+_end = .;}
 260   ${RELOCATING+${OTHER_BSS_END_SYMBOLS}}
 261   ${RELOCATING+PROVIDE (end = .);}
 262
 263   /* Stabs debugging sections.  */
 264   .stab 0 : { *(.stab) }
 265   .stabstr 0 : { *(.stabstr) }
 266   .stab.excl 0 : { *(.stab.excl) }
 267   .stab.exclstr 0 : { *(.stab.exclstr) }
 268   .stab.index 0 : { *(.stab.index) }
 269   .stab.indexstr 0 : { *(.stab.indexstr) }
 270
 271   .comment 0 : { *(.comment) }
 272
 273   /* DWARF debug sections.
 274      Symbols in the DWARF debugging sections are relative to the beginning
 275      of the section so we begin them at 0.  */
 276
 277   /* DWARF 1 */
 278   .debug          0 : { *(.debug) }
 279   .line           0 : { *(.line) }
 280
 281   /* GNU DWARF 1 extensions */
 282   .debug_srcinfo  0 : { *(.debug_srcinfo) }
 283   .debug_sfnames  0 : { *(.debug_sfnames) }
 284
 285   /* DWARF 1.1 and DWARF 2 */
 286   .debug_aranges  0 : { *(.debug_aranges) }
 287   .debug_pubnames 0 : { *(.debug_pubnames) }
 288
 289   /* DWARF 2 */
 290   .debug_info     0 : { *(.debug_info) }
 291   .debug_abbrev   0 : { *(.debug_abbrev) }
 292   .debug_line     0 : { *(.debug_line) }
 293   .debug_frame    0 : { *(.debug_frame) }
 294   .debug_str      0 : { *(.debug_str) }
 295   .debug_loc      0 : { *(.debug_loc) }
 296   .debug_macinfo  0 : { *(.debug_macinfo) }
 297
 298   /* SGI/MIPS DWARF 2 extensions */
 299   .debug_weaknames 0 : { *(.debug_weaknames) }
 300   .debug_funcnames 0 : { *(.debug_funcnames) }
 301   .debug_typenames 0 : { *(.debug_typenames) }
 302   .debug_varnames  0 : { *(.debug_varnames) }
 303
 304   ${RELOCATING+${OTHER_RELOCATING_SECTIONS}}
 305
 306   /* These must appear regardless of ${RELOCATING}.  */
 307   ${OTHER_SECTIONS}
 308 }
 309 EOF