ld/scripttempl/elf_chaos.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_SECTIONS - at the end
  14 #       EXECUTABLE_SYMBOLS - symbols that must be defined for an
  15 #               executable (e.g., _DYNAMIC_LINK)
  16 #       TEXT_START_SYMBOLS - symbols that appear at the start of the
  17 #               .text section.
  18 #       DATA_START_SYMBOLS - symbols that appear at the start of the
  19 #               .data section.
  20 #       OTHER_GOT_SYMBOLS - symbols defined just before .got.
  21 #       OTHER_GOT_SECTIONS - sections just after .got.
  22 #       OTHER_SDATA_SECTIONS - sections just after .sdata.
  23 #       OTHER_BSS_SYMBOLS - symbols that appear at the start of the
  24 #               .bss section besides __bss_start.
  25 #       DATA_PLT - .plt should be in data segment, not text segment.
  26 #       BSS_PLT - .plt should be in bss segment
  27 #       TEXT_DYNAMIC - .dynamic in text segment, not data segment.
  28 #       EMBEDDED - whether this is for an embedded system.
  29 #       SHLIB_TEXT_START_ADDR - if set, add to SIZEOF_HEADERS to set
  30 #               start address of shared library.
  31 #       INPUT_FILES - INPUT command of files to always include
  32 #       WRITABLE_RODATA - if set, the .rodata section should be writable
  33 #       INIT_START, INIT_END -  statements just before and just after
  34 #       combination of .init sections.
  35 #       FINI_START, FINI_END - statements just before and just after
  36 #       combination of .fini sections.
  37 #       STACK_ADDR - start of a .stack section.
  38 #       OTHER_SYMBOLS - symbols to place right at the end of the script.
  39 #
  40 # When adding sections, do note that the names of some sections are used
  41 # when specifying the start address of the next.
  42 #
  43
  44 #  Many sections come in three flavours.  There is the 'real' section,
  45 #  like ".data".  Then there are the per-procedure or per-variable
  46 #  sections, generated by -ffunction-sections and -fdata-sections in GCC,
  47 #  and useful for --gc-sections, which for a variable "foo" might be
  48 #  ".data.foo".  Then there are the linkonce sections, for which the linker
  49 #  eliminates duplicates, which are named like ".gnu.linkonce.d.foo".
  50 #  The exact correspondences are:
  51 #
  52 #  Section      Linkonce section
  53 #  .text        .gnu.linkonce.t.foo
  54 #  .rodata      .gnu.linkonce.r.foo
  55 #  .data        .gnu.linkonce.d.foo
  56 #  .bss         .gnu.linkonce.b.foo
  57 #  .sdata       .gnu.linkonce.s.foo
  58 #  .sbss        .gnu.linkonce.sb.foo
  59 #  .sdata2      .gnu.linkonce.s2.foo
  60 #  .sbss2       .gnu.linkonce.sb2.foo
  61 #  .debug_info  .gnu.linkonce.wi.foo
  62 #
  63 #  Each of these can also have corresponding .rel.* and .rela.* sections.
  64
  65 test -z "$ENTRY" && ENTRY=_start
  66 test -z "${BIG_OUTPUT_FORMAT}" && BIG_OUTPUT_FORMAT=${OUTPUT_FORMAT}
  67 test -z "${LITTLE_OUTPUT_FORMAT}" && LITTLE_OUTPUT_FORMAT=${OUTPUT_FORMAT}
  68 if [ -z "$MACHINE" ]; then OUTPUT_ARCH=${ARCH}; else OUTPUT_ARCH=${ARCH}:${MACHINE}; fi
  69 test -z "${ELFSIZE}" && ELFSIZE=32
  70 test -z "${ALIGNMENT}" && ALIGNMENT="${ELFSIZE} / 8"
  71 test "$LD_FLAG" = "N" && DATA_ADDR=.
  72 INTERP=".interp       ${RELOCATING-0} : { *(.interp) }"
  73 PLT=".plt          ${RELOCATING-0} : { *(.plt) }"
  74 DYNAMIC=".dynamic      ${RELOCATING-0} : { *(.dynamic) }"
  75 RODATA=".rodata       ${RELOCATING-0} : { *(.rodata${RELOCATING+ .rodata.* .gnu.linkonce.r.*}) }"
  76 if test -z "${NO_SMALL_DATA}"; then
  77   SBSS=".sbss         ${RELOCATING-0} :
  78   {
  79     ${RELOCATING+PROVIDE (__sbss_start = .);}
  80     ${RELOCATING+PROVIDE (___sbss_start = .);}
  81     *(.dynsbss)
  82     *(.sbss${RELOCATING+ .sbss.* .gnu.linkonce.sb.*})
  83     *(.scommon)
  84     ${RELOCATING+PROVIDE (__sbss_end = .);}
  85     ${RELOCATING+PROVIDE (___sbss_end = .);}
  86   }"
  87   SBSS2=".sbss2        ${RELOCATING-0} : { *(.sbss2${RELOCATING+ .sbss2.* .gnu.linkonce.sb2.*}) }"
  88   SDATA="/* We want the small data sections together, so single-instruction offsets
  89      can access them all, and initialized data all before uninitialized, so
  90      we can shorten the on-disk segment size.  */
  91   .sdata        ${RELOCATING-0} :
  92   {
  93     ${RELOCATING+${SDATA_START_SYMBOLS}}
  94     *(.sdata${RELOCATING+ .sdata.* .gnu.linkonce.s.*})
  95   }"
  96   SDATA2=".sdata2       ${RELOCATING-0} : { *(.sdata2${RELOCATING+ .sdata2.* .gnu.linkonce.s2.*}) }"
  97   REL_SDATA=".rel.sdata    ${RELOCATING-0} : { *(.rel.sdata${RELOCATING+ .rel.sdata.* .rel.gnu.linkonce.s.*}) }
  98   .rela.sdata   ${RELOCATING-0} : { *(.rela.sdata${RELOCATING+ .rela.sdata.* .rela.gnu.linkonce.s.*}) }"
  99   REL_SBSS=".rel.sbss     ${RELOCATING-0} : { *(.rel.sbss${RELOCATING+ .rel.sbss.* .rel.gnu.linkonce.sb.*}) }
 100   .rela.sbss    ${RELOCATING-0} : { *(.rela.sbss${RELOCATING+ .rela.sbss.* .rela.gnu.linkonce.sb.*}) }"
 101   REL_SDATA2=".rel.sdata2   ${RELOCATING-0} : { *(.rel.sdata2${RELOCATING+ .rel.sdata2.* .rel.gnu.linkonce.s2.*}) }
 102   .rela.sdata2  ${RELOCATING-0} : { *(.rela.sdata2${RELOCATING+ .rela.sdata2.* .rela.gnu.linkonce.s2.*}) }"
 103   REL_SBSS2=".rel.sbss2    ${RELOCATING-0} : { *(.rel.sbss2${RELOCATING+ .rel.sbss2.* .rel.gnu.linkonce.sb2.*}) }
 104   .rela.sbss2   ${RELOCATING-0} : { *(.rela.sbss2${RELOCATING+ .rela.sbss2.* .rela.gnu.linkonce.sb2.*}) }"
 105 fi
 106 CTOR="
 107     ${CONSTRUCTING+${CTOR_START}}
 108     /* gcc uses crtbegin.o to find the start of
 109        the constructors, so we make sure it is
 110        first.  Because this is a wildcard, it
 111        doesn't matter if the user does not
 112        actually link against crtbegin.o; the
 113        linker won't look for a file to match a
 114        wildcard.  The wildcard also means that it
 115        doesn't matter which directory crtbegin.o
 116        is in.  */
 117
 118     KEEP (*crtbegin*.o(.ctors))
 119
 120     /* We don't want to include the .ctor section from
 121        the crtend.o file until after the sorted ctors.
 122        The .ctor section from the crtend file contains the
 123        end of ctors marker and it must be last */
 124
 125     KEEP (*(EXCLUDE_FILE (*crtend*.o $OTHER_EXCLUDE_FILES) .ctors))
 126     KEEP (*(SORT(.ctors.*)))
 127     KEEP (*(.ctors))
 128     ${CONSTRUCTING+${CTOR_END}}
 129 "
 130 DTOR="
 131     ${CONSTRUCTING+${DTOR_START}}
 132     KEEP (*crtbegin*.o(.dtors))
 133     KEEP (*(EXCLUDE_FILE (*crtend*.o $OTHER_EXCLUDE_FILES) .dtors))
 134     KEEP (*(SORT(.dtors.*)))
 135     KEEP (*(.dtors))
 136     ${CONSTRUCTING+${DTOR_END}}
 137 "
 138 STACK="  .stack        ${RELOCATING-0}${RELOCATING+${STACK_ADDR}} :
 139   {
 140     ${RELOCATING+_stack = .;}
 141     *(.stack)
 142   }"
 143
 144 test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR}"
 145
 146 cat <<EOF
 147 OUTPUT_FORMAT("${OUTPUT_FORMAT}", "${BIG_OUTPUT_FORMAT}",
 148               "${LITTLE_OUTPUT_FORMAT}")
 149 OUTPUT_ARCH(${OUTPUT_ARCH})
 150 ENTRY(${ENTRY})
 151
 152 ${RELOCATING+${LIB_SEARCH_DIRS}}
 153 ${RELOCATING+/* Do we need any of these for elf?
 154    __DYNAMIC = 0; ${STACKZERO+${STACKZERO}} ${SHLIB_PATH+${SHLIB_PATH}}  */}
 155 ${RELOCATING+${EXECUTABLE_SYMBOLS}}
 156 ${RELOCATING+${INPUT_FILES}}
 157 ${RELOCATING- /* For some reason, the Solaris linker makes bad executables
 158   if gld -r is used and the intermediate file has sections starting
 159   at non-zero addresses.  Could be a Solaris ld bug, could be a GNU ld
 160   bug.  But for now assigning the zero vmas works.  */}
 161
 162 SECTIONS
 163 {
 164   /* Read-only sections, merged into text segment: */
 165   ${CREATE_SHLIB-${RELOCATING+. = ${TEXT_BASE_ADDRESS};}}
 166   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_TEXT_START_ADDR:-0};}}
 167   ${CREATE_SHLIB-${INTERP}}
 168   ${INITIAL_READONLY_SECTIONS}
 169   ${TEXT_DYNAMIC+${DYNAMIC}}
 170   .hash         ${RELOCATING-0} : { *(.hash) }
 171   .dynsym       ${RELOCATING-0} : { *(.dynsym) }
 172   .dynstr       ${RELOCATING-0} : { *(.dynstr) }
 173   .gnu.version  ${RELOCATING-0} : { *(.gnu.version) }
 174   .gnu.version_d ${RELOCATING-0}: { *(.gnu.version_d) }
 175   .gnu.version_r ${RELOCATING-0}: { *(.gnu.version_r) }
 176
 177 EOF
 178 if [ "x$COMBRELOC" = x ]; then
 179   COMBRELOCCAT=cat
 180 else
 181   COMBRELOCCAT="cat > $COMBRELOC"
 182 fi
 183 eval $COMBRELOCCAT <<EOF
 184   .rel.init     ${RELOCATING-0} : { *(.rel.init) }
 185   .rela.init    ${RELOCATING-0} : { *(.rela.init) }
 186   .rel.text     ${RELOCATING-0} : { *(.rel.text${RELOCATING+ .rel.text.* .rel.gnu.linkonce.t.*}) }
 187   .rela.text    ${RELOCATING-0} : { *(.rela.text${RELOCATING+ .rela.text.* .rela.gnu.linkonce.t.*}) }
 188   .rel.fini     ${RELOCATING-0} : { *(.rel.fini) }
 189   .rela.fini    ${RELOCATING-0} : { *(.rela.fini) }
 190   .rel.rodata   ${RELOCATING-0} : { *(.rel.rodata${RELOCATING+ .rel.rodata.* .rel.gnu.linkonce.r.*}) }
 191   .rela.rodata  ${RELOCATING-0} : { *(.rela.rodata${RELOCATING+ .rela.rodata.* .rela.gnu.linkonce.r.*}) }
 192   ${OTHER_READONLY_RELOC_SECTIONS}
 193   .rel.data     ${RELOCATING-0} : { *(.rel.data${RELOCATING+ .rel.data.* .rel.gnu.linkonce.d.*}) }
 194   .rela.data    ${RELOCATING-0} : { *(.rela.data${RELOCATING+ .rela.data.* .rela.gnu.linkonce.d.*}) }
 195   .rel.ctors    ${RELOCATING-0} : { *(.rel.ctors) }
 196   .rela.ctors   ${RELOCATING-0} : { *(.rela.ctors) }
 197   .rel.dtors    ${RELOCATING-0} : { *(.rel.dtors) }
 198   .rela.dtors   ${RELOCATING-0} : { *(.rela.dtors) }
 199   .rel.got      ${RELOCATING-0} : { *(.rel.got) }
 200   .rela.got     ${RELOCATING-0} : { *(.rela.got) }
 201   ${OTHER_GOT_RELOC_SECTIONS}
 202   ${REL_SDATA}
 203   ${REL_SBSS}
 204   ${REL_SDATA2}
 205   ${REL_SBSS2}
 206   .rel.bss      ${RELOCATING-0} : { *(.rel.bss${RELOCATING+ .rel.bss.* .rel.gnu.linkonce.b.*}) }
 207   .rela.bss     ${RELOCATING-0} : { *(.rela.bss${RELOCATING+ .rela.bss.* .rela.gnu.linkonce.b.*}) }
 208 EOF
 209 if [ -n "$COMBRELOC" ]; then
 210 cat <<EOF
 211   .rel.dyn      ${RELOCATING-0} :
 212     {
 213 EOF
 214 sed -e '/^[     ]*[{}][         ]*$/d;/:[       ]*$/d;/\.rela\./d;s/^.*: { *\(.*\)}$/      \1/' $COMBRELOC
 215 cat <<EOF
 216     }
 217   .rela.dyn     ${RELOCATING-0} :
 218     {
 219 EOF
 220 sed -e '/^[     ]*[{}][         ]*$/d;/:[       ]*$/d;/\.rel\./d;s/^.*: { *\(.*\)}/      \1/' $COMBRELOC
 221 cat <<EOF
 222     }
 223 EOF
 224 fi
 225 cat <<EOF
 226   . = ALIGN(0x1000);
 227   .rel.plt      ${RELOCATING-0} : { *(.rel.plt) }
 228   .rela.plt     ${RELOCATING-0} : { *(.rela.plt) }
 229   ${OTHER_PLT_RELOC_SECTIONS}
 230   ${DATA_PLT-${BSS_PLT-${PLT}}}
 231   .text         ${RELOCATING-0} :
 232   {
 233     ${RELOCATING+${TEXT_START_SYMBOLS}}
 234     *(.text .stub${RELOCATING+ .text.* .gnu.linkonce.t.*})
 235     /* .gnu.warning sections are handled specially by elf32.em.  */
 236     *(.gnu.warning)
 237     ${RELOCATING+${OTHER_TEXT_SECTIONS}}
 238   } =${NOP-0}
 239   .fini         ${RELOCATING-0} :
 240   {
 241     ${RELOCATING+${FINI_START}}
 242     KEEP (*(.fini))
 243     ${RELOCATING+${FINI_END}}
 244   } =${NOP-0}
 245   ${RELOCATING+PROVIDE (__etext = .);}
 246   ${RELOCATING+PROVIDE (_etext = .);}
 247   ${RELOCATING+PROVIDE (etext = .);}
 248   . = ALIGN(0x1000);
 249   ${CREATE_SHLIB-${SDATA2}}
 250   ${CREATE_SHLIB-${SBSS2}}
 251   ${OTHER_READONLY_SECTIONS}
 252   .eh_frame_hdr : { *(.eh_frame_hdr) }
 253
 254   . = ALIGN(0x1000);
 255   .data         ${RELOCATING-0} :
 256   {
 257     *(.rodata .rodata.*)
 258     *(.rodata1)
 259     *(.gnu.linkonce.r.*)
 260     ${RELOCATING+${DATA_START_SYMBOLS}}
 261     *(.data${RELOCATING+ .data.* .gnu.linkonce.d.*})
 262     ${CONSTRUCTING+SORT(CONSTRUCTORS)}
 263     KEEP (*(.eh_frame))
 264     *(.gcc_except_table)
 265     ${CTOR}
 266     ${DTOR}
 267     KEEP (*(.jcr))
 268   }
 269   .data1        ${RELOCATING-0} : { *(.data1) }
 270   . = ALIGN(0x1000);
 271   .gcc_except_table ${RELOCATING-0} : { *(.gcc_except_table) }
 272   ${WRITABLE_RODATA+${RODATA}}
 273   ${OTHER_READWRITE_SECTIONS}
 274   ${TEXT_DYNAMIC-${DYNAMIC}}
 275   ${DATA_PLT+${PLT}}
 276   ${RELOCATING+${OTHER_GOT_SYMBOLS}}
 277   .got          ${RELOCATING-0} : { *(.got.plt) *(.got) }
 278   ${OTHER_GOT_SECTIONS}
 279   ${CREATE_SHLIB+${SDATA2}}
 280   ${CREATE_SHLIB+${SBSS2}}
 281   ${SDATA}
 282   ${OTHER_SDATA_SECTIONS}
 283   ${RELOCATING+_edata = .;}
 284   ${RELOCATING+PROVIDE (edata = .);}
 285   ${RELOCATING+__bss_start = .;}
 286   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
 287   ${SBSS}
 288   ${BSS_PLT+${PLT}}
 289   . = ALIGN(0x1000);
 290   .bss          ${RELOCATING-0} :
 291   {
 292    *(.dynbss)
 293    *(.bss${RELOCATING+ .bss.* .gnu.linkonce.b.*})
 294    *(COMMON)
 295    /* Align here to ensure that the .bss section occupies space up to
 296       _end.  Align after .bss to ensure correct alignment even if the
 297       .bss section disappears because there are no input sections.  */
 298    ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 299   }
 300   ${RELOCATING+${OTHER_BSS_END_SYMBOLS}}
 301   ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 302   ${RELOCATING+${OTHER_END_SYMBOLS}}
 303   ${RELOCATING+_end = .;}
 304   ${RELOCATING+PROVIDE (end = .);}
 305
 306   /* Stabs debugging sections.  */
 307   . = ALIGN(0x1000);
 308   .stab          0 : { *(.stab) }
 309   .stabstr       0 : { *(.stabstr) }
 310   .stab.excl     0 : { *(.stab.excl) }
 311   .stab.exclstr  0 : { *(.stab.exclstr) }
 312   .stab.index    0 : { *(.stab.index) }
 313   .stab.indexstr 0 : { *(.stab.indexstr) }
 314
 315   . = ALIGN(0x1000);
 316   .comment       0 : { *(.comment) }
 317
 318   /* DWARF debug sections.
 319      Symbols in the DWARF debugging sections are relative to the beginning
 320      of the section so we begin them at 0.  */
 321
 322   /* DWARF 1 */
 323   .debug          0 : { *(.debug) }
 324   .line           0 : { *(.line) }
 325
 326   /* GNU DWARF 1 extensions */
 327   .debug_srcinfo  0 : { *(.debug_srcinfo) }
 328   .debug_sfnames  0 : { *(.debug_sfnames) }
 329
 330   /* DWARF 1.1 and DWARF 2 */
 331   .debug_aranges  0 : { *(.debug_aranges) }
 332   .debug_pubnames 0 : { *(.debug_pubnames) }
 333
 334   /* DWARF 2 */
 335   .debug_info     0 : { *(.debug_info .gnu.linkonce.wi.*) }
 336   .debug_abbrev   0 : { *(.debug_abbrev) }
 337   .debug_line     0 : { *(.debug_line) }
 338   .debug_frame    0 : { *(.debug_frame) }
 339   .debug_str      0 : { *(.debug_str) }
 340   .debug_loc      0 : { *(.debug_loc) }
 341   .debug_macinfo  0 : { *(.debug_macinfo) }
 342
 343   /* SGI/MIPS DWARF 2 extensions */
 344   .debug_weaknames 0 : { *(.debug_weaknames) }
 345   .debug_funcnames 0 : { *(.debug_funcnames) }
 346   .debug_typenames 0 : { *(.debug_typenames) }
 347   .debug_varnames  0 : { *(.debug_varnames) }
 348
 349   ${STACK_ADDR+${STACK}}
 350   ${OTHER_SECTIONS}
 351   ${RELOCATING+${OTHER_SYMBOLS}}
 352 }
 353 EOF