ld/scripttempl/elf.sc

   1 #
   2 # Unusual variables checked by this code:
   3 #       NOP - four byte opcode for no-op (defaults to 0)
   4 #       NO_SMALL_DATA - no .sbss/.sbss2/.sdata/.sdata2 sections if not
   5 #               empty.
   6 #       DATA_ADDR - if end-of-text-plus-one-page isn't right for data start
   7 #       INITIAL_READONLY_SECTIONS - at start of text segment
   8 #       OTHER_READONLY_SECTIONS - other than .text .init .rodata ...
   9 #               (e.g., .PARISC.milli)
  10 #       OTHER_TEXT_SECTIONS - these get put in .text when relocating
  11 #       OTHER_READWRITE_SECTIONS - other than .data .bss .ctors .sdata ...
  12 #               (e.g., .PARISC.global)
  13 #       OTHER_BSS_SECTIONS - other than .bss .sbss ...
  14 #       OTHER_SECTIONS - at the end
  15 #       EXECUTABLE_SYMBOLS - symbols that must be defined for an
  16 #               executable (e.g., _DYNAMIC_LINK)
  17 #       TEXT_START_SYMBOLS - symbols that appear at the start of the
  18 #               .text section.
  19 #       DATA_START_SYMBOLS - symbols that appear at the start of the
  20 #               .data section.
  21 #       OTHER_GOT_SYMBOLS - symbols defined just before .got.
  22 #       OTHER_GOT_SECTIONS - sections just after .got.
  23 #       OTHER_SDATA_SECTIONS - sections just after .sdata.
  24 #       OTHER_BSS_SYMBOLS - symbols that appear at the start of the
  25 #               .bss section besides __bss_start.
  26 #       DATA_PLT - .plt should be in data segment, not text segment.
  27 #       BSS_PLT - .plt should be in bss segment
  28 #       TEXT_DYNAMIC - .dynamic in text segment, not data segment.
  29 #       EMBEDDED - whether this is for an embedded system.
  30 #       SHLIB_TEXT_START_ADDR - if set, add to SIZEOF_HEADERS to set
  31 #               start address of shared library.
  32 #       INPUT_FILES - INPUT command of files to always include
  33 #       WRITABLE_RODATA - if set, the .rodata section should be writable
  34 #       INIT_START, INIT_END -  statements just before and just after
  35 #       combination of .init sections.
  36 #       FINI_START, FINI_END - statements just before and just after
  37 #       combination of .fini sections.
  38 #       STACK_ADDR - start of a .stack section.
  39 #       OTHER_END_SYMBOLS - symbols to place right at the end of the script.
  40 #
  41 # When adding sections, do note that the names of some sections are used
  42 # when specifying the start address of the next.
  43 #
  44
  45 #  Many sections come in three flavours.  There is the 'real' section,
  46 #  like ".data".  Then there are the per-procedure or per-variable
  47 #  sections, generated by -ffunction-sections and -fdata-sections in GCC,
  48 #  and useful for --gc-sections, which for a variable "foo" might be
  49 #  ".data.foo".  Then there are the linkonce sections, for which the linker
  50 #  eliminates duplicates, which are named like ".gnu.linkonce.d.foo".
  51 #  The exact correspondences are:
  52 #
  53 #  Section      Linkonce section
  54 #  .text        .gnu.linkonce.t.foo
  55 #  .rodata      .gnu.linkonce.r.foo
  56 #  .data        .gnu.linkonce.d.foo
  57 #  .bss         .gnu.linkonce.b.foo
  58 #  .sdata       .gnu.linkonce.s.foo
  59 #  .sbss        .gnu.linkonce.sb.foo
  60 #  .sdata2      .gnu.linkonce.s2.foo
  61 #  .sbss2       .gnu.linkonce.sb2.foo
  62 #  .debug_info  .gnu.linkonce.wi.foo
  63 #
  64 #  Each of these can also have corresponding .rel.* and .rela.* sections.
  65
  66 test -z "$ENTRY" && ENTRY=_start
  67 test -z "${BIG_OUTPUT_FORMAT}" && BIG_OUTPUT_FORMAT=${OUTPUT_FORMAT}
  68 test -z "${LITTLE_OUTPUT_FORMAT}" && LITTLE_OUTPUT_FORMAT=${OUTPUT_FORMAT}
  69 if [ -z "$MACHINE" ]; then OUTPUT_ARCH=${ARCH}; else OUTPUT_ARCH=${ARCH}:${MACHINE}; fi
  70 test -z "${ELFSIZE}" && ELFSIZE=32
  71 test -z "${ALIGNMENT}" && ALIGNMENT="${ELFSIZE} / 8"
  72 test "$LD_FLAG" = "N" && DATA_ADDR=.
  73 INTERP=".interp       ${RELOCATING-0} : { *(.interp) }"
  74 PLT=".plt          ${RELOCATING-0} : { *(.plt) }"
  75 DYNAMIC=".dynamic      ${RELOCATING-0} : { *(.dynamic) }"
  76 RODATA=".rodata       ${RELOCATING-0} : { *(.rodata${RELOCATING+ .rodata.* .gnu.linkonce.r.*}) }"
  77 if test -z "${NO_SMALL_DATA}"; then
  78   SBSS=".sbss         ${RELOCATING-0} :
  79   {
  80     ${RELOCATING+PROVIDE (__sbss_start = .);}
  81     ${RELOCATING+PROVIDE (___sbss_start = .);}
  82     *(.dynsbss)
  83     *(.sbss${RELOCATING+ .sbss.* .gnu.linkonce.sb.*})
  84     *(.scommon)
  85     ${RELOCATING+PROVIDE (__sbss_end = .);}
  86     ${RELOCATING+PROVIDE (___sbss_end = .);}
  87   }"
  88   SBSS2=".sbss2        ${RELOCATING-0} : { *(.sbss2${RELOCATING+ .sbss2.* .gnu.linkonce.sb2.*}) }"
  89   SDATA="/* We want the small data sections together, so single-instruction offsets
  90      can access them all, and initialized data all before uninitialized, so
  91      we can shorten the on-disk segment size.  */
  92   .sdata        ${RELOCATING-0} :
  93   {
  94     ${RELOCATING+${SDATA_START_SYMBOLS}}
  95     *(.sdata${RELOCATING+ .sdata.* .gnu.linkonce.s.*})
  96   }"
  97   SDATA2=".sdata2       ${RELOCATING-0} : { *(.sdata2${RELOCATING+ .sdata2.* .gnu.linkonce.s2.*}) }"
  98   REL_SDATA=".rel.sdata    ${RELOCATING-0} : { *(.rel.sdata${RELOCATING+ .rel.sdata.* .rel.gnu.linkonce.s.*}) }
  99   .rela.sdata   ${RELOCATING-0} : { *(.rela.sdata${RELOCATING+ .rela.sdata.* .rela.gnu.linkonce.s.*}) }"
 100   REL_SBSS=".rel.sbss     ${RELOCATING-0} : { *(.rel.sbss${RELOCATING+ .rel.sbss.* .rel.gnu.linkonce.sb.*}) }
 101   .rela.sbss    ${RELOCATING-0} : { *(.rela.sbss${RELOCATING+ .rela.sbss.* .rela.gnu.linkonce.sb.*}) }"
 102   REL_SDATA2=".rel.sdata2   ${RELOCATING-0} : { *(.rel.sdata2${RELOCATING+ .rel.sdata2.* .rel.gnu.linkonce.s2.*}) }
 103   .rela.sdata2  ${RELOCATING-0} : { *(.rela.sdata2${RELOCATING+ .rela.sdata2.* .rela.gnu.linkonce.s2.*}) }"
 104   REL_SBSS2=".rel.sbss2    ${RELOCATING-0} : { *(.rel.sbss2${RELOCATING+ .rel.sbss2.* .rel.gnu.linkonce.sb2.*}) }
 105   .rela.sbss2   ${RELOCATING-0} : { *(.rela.sbss2${RELOCATING+ .rela.sbss2.* .rela.gnu.linkonce.sb2.*}) }"
 106 fi
 107 CTOR=".ctors        ${CONSTRUCTING-0} :
 108   {
 109     ${CONSTRUCTING+${CTOR_START}}
 110     /* gcc uses crtbegin.o to find the start of
 111        the constructors, so we make sure it is
 112        first.  Because this is a wildcard, it
 113        doesn't matter if the user does not
 114        actually link against crtbegin.o; the
 115        linker won't look for a file to match a
 116        wildcard.  The wildcard also means that it
 117        doesn't matter which directory crtbegin.o
 118        is in.  */
 119
 120     KEEP (*crtbegin.o(.ctors))
 121
 122     /* We don't want to include the .ctor section from
 123        from the crtend.o file until after the sorted ctors.
 124        The .ctor section from the crtend file contains the
 125        end of ctors marker and it must be last */
 126
 127     KEEP (*(EXCLUDE_FILE (*crtend.o $OTHER_EXCLUDE_FILES) .ctors))
 128     KEEP (*(SORT(.ctors.*)))
 129     KEEP (*(.ctors))
 130     ${CONSTRUCTING+${CTOR_END}}
 131   }"
 132 DTOR=".dtors        ${CONSTRUCTING-0} :
 133   {
 134     ${CONSTRUCTING+${DTOR_START}}
 135     KEEP (*crtbegin.o(.dtors))
 136     KEEP (*(EXCLUDE_FILE (*crtend.o $OTHER_EXCLUDE_FILES) .dtors))
 137     KEEP (*(SORT(.dtors.*)))
 138     KEEP (*(.dtors))
 139     ${CONSTRUCTING+${DTOR_END}}
 140   }"
 141 STACK="  .stack        ${RELOCATING-0}${RELOCATING+${STACK_ADDR}} :
 142   {
 143     ${RELOCATING+_stack = .;}
 144     *(.stack)
 145   }"
 146
 147 # if this is for an embedded system, don't add SIZEOF_HEADERS.
 148 if [ -z "$EMBEDDED" ]; then
 149    test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR} + SIZEOF_HEADERS"
 150 else
 151    test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR}"
 152 fi
 153
 154 cat <<EOF
 155 OUTPUT_FORMAT("${OUTPUT_FORMAT}", "${BIG_OUTPUT_FORMAT}",
 156               "${LITTLE_OUTPUT_FORMAT}")
 157 OUTPUT_ARCH(${OUTPUT_ARCH})
 158 ENTRY(${ENTRY})
 159
 160 ${RELOCATING+${LIB_SEARCH_DIRS}}
 161 ${RELOCATING+/* Do we need any of these for elf?
 162    __DYNAMIC = 0; ${STACKZERO+${STACKZERO}} ${SHLIB_PATH+${SHLIB_PATH}}  */}
 163 ${RELOCATING+${EXECUTABLE_SYMBOLS}}
 164 ${RELOCATING+${INPUT_FILES}}
 165 ${RELOCATING- /* For some reason, the Solaris linker makes bad executables
 166   if gld -r is used and the intermediate file has sections starting
 167   at non-zero addresses.  Could be a Solaris ld bug, could be a GNU ld
 168   bug.  But for now assigning the zero vmas works.  */}
 169
 170 SECTIONS
 171 {
 172   /* Read-only sections, merged into text segment: */
 173   ${CREATE_SHLIB-${RELOCATING+. = ${TEXT_BASE_ADDRESS};}}
 174   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_TEXT_START_ADDR:-0} + SIZEOF_HEADERS;}}
 175   ${CREATE_SHLIB-${INTERP}}
 176   ${INITIAL_READONLY_SECTIONS}
 177   ${TEXT_DYNAMIC+${DYNAMIC}}
 178   .hash         ${RELOCATING-0} : { *(.hash) }
 179   .dynsym       ${RELOCATING-0} : { *(.dynsym) }
 180   .dynstr       ${RELOCATING-0} : { *(.dynstr) }
 181   .gnu.version  ${RELOCATING-0} : { *(.gnu.version) }
 182   .gnu.version_d ${RELOCATING-0}: { *(.gnu.version_d) }
 183   .gnu.version_r ${RELOCATING-0}: { *(.gnu.version_r) }
 184
 185 EOF
 186 if [ "x$COMBRELOC" = x ]; then
 187   COMBRELOCCAT=cat
 188 else
 189   COMBRELOCCAT="cat > $COMBRELOC"
 190 fi
 191 eval $COMBRELOCCAT <<EOF
 192   .rel.init     ${RELOCATING-0} : { *(.rel.init) }
 193   .rela.init    ${RELOCATING-0} : { *(.rela.init) }
 194   .rel.text     ${RELOCATING-0} : { *(.rel.text${RELOCATING+ .rel.text.* .rel.gnu.linkonce.t.*}) }
 195   .rela.text    ${RELOCATING-0} : { *(.rela.text${RELOCATING+ .rela.text.* .rela.gnu.linkonce.t.*}) }
 196   .rel.fini     ${RELOCATING-0} : { *(.rel.fini) }
 197   .rela.fini    ${RELOCATING-0} : { *(.rela.fini) }
 198   .rel.rodata   ${RELOCATING-0} : { *(.rel.rodata${RELOCATING+ .rel.rodata.* .rel.gnu.linkonce.r.*}) }
 199   .rela.rodata  ${RELOCATING-0} : { *(.rela.rodata${RELOCATING+ .rela.rodata.* .rela.gnu.linkonce.r.*}) }
 200   ${OTHER_READONLY_RELOC_SECTIONS}
 201   .rel.data     ${RELOCATING-0} : { *(.rel.data${RELOCATING+ .rel.data.* .rel.gnu.linkonce.d.*}) }
 202   .rela.data    ${RELOCATING-0} : { *(.rela.data${RELOCATING+ .rela.data.* .rela.gnu.linkonce.d.*}) }
 203   .rel.ctors    ${RELOCATING-0} : { *(.rel.ctors) }
 204   .rela.ctors   ${RELOCATING-0} : { *(.rela.ctors) }
 205   .rel.dtors    ${RELOCATING-0} : { *(.rel.dtors) }
 206   .rela.dtors   ${RELOCATING-0} : { *(.rela.dtors) }
 207   .rel.got      ${RELOCATING-0} : { *(.rel.got) }
 208   .rela.got     ${RELOCATING-0} : { *(.rela.got) }
 209   ${OTHER_GOT_RELOC_SECTIONS}
 210   ${REL_SDATA}
 211   ${REL_SBSS}
 212   ${REL_SDATA2}
 213   ${REL_SBSS2}
 214   .rel.bss      ${RELOCATING-0} : { *(.rel.bss${RELOCATING+ .rel.bss.* .rel.gnu.linkonce.b.*}) }
 215   .rela.bss     ${RELOCATING-0} : { *(.rela.bss${RELOCATING+ .rela.bss.* .rela.gnu.linkonce.b.*}) }
 216 EOF
 217 if [ -n "$COMBRELOC" ]; then
 218 cat <<EOF
 219   .rel.dyn      ${RELOCATING-0} :
 220     {
 221 EOF
 222 sed -e '/^[     ]*[{}][         ]*$/d;/:[       ]*$/d;/\.rela\./d;s/^.*: { *\(.*\)}$/      \1/' $COMBRELOC
 223 cat <<EOF
 224     }
 225   .rela.dyn     ${RELOCATING-0} :
 226     {
 227 EOF
 228 sed -e '/^[     ]*[{}][         ]*$/d;/:[       ]*$/d;/\.rel\./d;s/^.*: { *\(.*\)}/      \1/' $COMBRELOC
 229 cat <<EOF
 230     }
 231 EOF
 232 fi
 233 cat <<EOF
 234   .rel.plt      ${RELOCATING-0} : { *(.rel.plt) }
 235   .rela.plt     ${RELOCATING-0} : { *(.rela.plt) }
 236   ${OTHER_PLT_RELOC_SECTIONS}
 237
 238   .init         ${RELOCATING-0} :
 239   {
 240     ${RELOCATING+${INIT_START}}
 241     KEEP (*(.init))
 242     ${RELOCATING+${INIT_END}}
 243   } =${NOP-0}
 244
 245   ${DATA_PLT-${BSS_PLT-${PLT}}}
 246   .text         ${RELOCATING-0} :
 247   {
 248     ${RELOCATING+${TEXT_START_SYMBOLS}}
 249     *(.text .stub${RELOCATING+ .text.* .gnu.linkonce.t.*})
 250     /* .gnu.warning sections are handled specially by elf32.em.  */
 251     *(.gnu.warning)
 252     ${RELOCATING+${OTHER_TEXT_SECTIONS}}
 253   } =${NOP-0}
 254   .fini         ${RELOCATING-0} :
 255   {
 256     ${RELOCATING+${FINI_START}}
 257     KEEP (*(.fini))
 258     ${RELOCATING+${FINI_END}}
 259   } =${NOP-0}
 260   ${RELOCATING+PROVIDE (__etext = .);}
 261   ${RELOCATING+PROVIDE (_etext = .);}
 262   ${RELOCATING+PROVIDE (etext = .);}
 263   ${WRITABLE_RODATA-${RODATA}}
 264   .rodata1      ${RELOCATING-0} : { *(.rodata1) }
 265   ${CREATE_SHLIB-${SDATA2}}
 266   ${CREATE_SHLIB-${SBSS2}}
 267   ${OTHER_READONLY_SECTIONS}
 268
 269   /* Adjust the address for the data segment.  We want to adjust up to
 270      the same address within the page on the next page up.  */
 271   ${CREATE_SHLIB-${RELOCATING+. = ${DATA_ADDR-ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))};}}
 272   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_DATA_ADDR-ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))};}}
 273
 274   .data         ${RELOCATING-0} :
 275   {
 276     ${RELOCATING+${DATA_START_SYMBOLS}}
 277     *(.data${RELOCATING+ .data.* .gnu.linkonce.d.*})
 278     ${CONSTRUCTING+SORT(CONSTRUCTORS)}
 279   }
 280   .data1        ${RELOCATING-0} : { *(.data1) }
 281   .eh_frame     ${RELOCATING-0} : { KEEP (*(.eh_frame)) }
 282   .gcc_except_table ${RELOCATING-0} : { *(.gcc_except_table) }
 283   ${WRITABLE_RODATA+${RODATA}}
 284   ${OTHER_READWRITE_SECTIONS}
 285   ${TEXT_DYNAMIC-${DYNAMIC}}
 286   ${RELOCATING+${CTOR}}
 287   ${RELOCATING+${DTOR}}
 288   .jcr          ${RELOCATING-0} : { KEEP (*(.jcr)) }
 289   ${DATA_PLT+${PLT}}
 290   ${RELOCATING+${OTHER_GOT_SYMBOLS}}
 291   .got          ${RELOCATING-0} : { *(.got.plt) *(.got) }
 292   ${OTHER_GOT_SECTIONS}
 293   ${CREATE_SHLIB+${SDATA2}}
 294   ${CREATE_SHLIB+${SBSS2}}
 295   ${SDATA}
 296   ${OTHER_SDATA_SECTIONS}
 297   ${RELOCATING+_edata = .;}
 298   ${RELOCATING+PROVIDE (edata = .);}
 299   ${RELOCATING+__bss_start = .;}
 300   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
 301   ${SBSS}
 302   ${BSS_PLT+${PLT}}
 303   .bss          ${RELOCATING-0} :
 304   {
 305    *(.dynbss)
 306    *(.bss${RELOCATING+ .bss.* .gnu.linkonce.b.*})
 307    *(COMMON)
 308    /* Align here to ensure that the .bss section occupies space up to
 309       _end.  Align after .bss to ensure correct alignment even if the
 310       .bss section disappears because there are no input sections.  */
 311    ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 312   }
 313   ${OTHER_BSS_SECTIONS}
 314   ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 315   ${RELOCATING+_end = .;}
 316   ${RELOCATING+${OTHER_BSS_END_SYMBOLS}}
 317   ${RELOCATING+PROVIDE (end = .);}
 318
 319   /* Stabs debugging sections.  */
 320   .stab          0 : { *(.stab) }
 321   .stabstr       0 : { *(.stabstr) }
 322   .stab.excl     0 : { *(.stab.excl) }
 323   .stab.exclstr  0 : { *(.stab.exclstr) }
 324   .stab.index    0 : { *(.stab.index) }
 325   .stab.indexstr 0 : { *(.stab.indexstr) }
 326
 327   .comment       0 : { *(.comment) }
 328
 329   /* DWARF debug sections.
 330      Symbols in the DWARF debugging sections are relative to the beginning
 331      of the section so we begin them at 0.  */
 332
 333   /* DWARF 1 */
 334   .debug          0 : { *(.debug) }
 335   .line           0 : { *(.line) }
 336
 337   /* GNU DWARF 1 extensions */
 338   .debug_srcinfo  0 : { *(.debug_srcinfo) }
 339   .debug_sfnames  0 : { *(.debug_sfnames) }
 340
 341   /* DWARF 1.1 and DWARF 2 */
 342   .debug_aranges  0 : { *(.debug_aranges) }
 343   .debug_pubnames 0 : { *(.debug_pubnames) }
 344
 345   /* DWARF 2 */
 346   .debug_info     0 : { *(.debug_info .gnu.linkonce.wi.*) }
 347   .debug_abbrev   0 : { *(.debug_abbrev) }
 348   .debug_line     0 : { *(.debug_line) }
 349   .debug_frame    0 : { *(.debug_frame) }
 350   .debug_str      0 : { *(.debug_str) }
 351   .debug_loc      0 : { *(.debug_loc) }
 352   .debug_macinfo  0 : { *(.debug_macinfo) }
 353
 354   /* SGI/MIPS DWARF 2 extensions */
 355   .debug_weaknames 0 : { *(.debug_weaknames) }
 356   .debug_funcnames 0 : { *(.debug_funcnames) }
 357   .debug_typenames 0 : { *(.debug_typenames) }
 358   .debug_varnames  0 : { *(.debug_varnames) }
 359
 360   ${STACK_ADDR+${STACK}}
 361   ${OTHER_SECTIONS}
 362   ${RELOCATING+${OTHER_END_SYMBOLS}}
 363 }
 364 EOF