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     KEEP (*crtbegin?.o(.ctors))
 120
 121     /* We don't want to include the .ctor section from
 122        the crtend.o file until after the sorted ctors.
 123        The .ctor section from the crtend file contains the
 124        end of ctors marker and it must be last */
 125
 126     KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o $OTHER_EXCLUDE_FILES) .ctors))
 127     KEEP (*(SORT(.ctors.*)))
 128     KEEP (*(.ctors))
 129     ${CONSTRUCTING+${CTOR_END}}
 130 "
 131 DTOR="
 132     ${CONSTRUCTING+${DTOR_START}}
 133     KEEP (*crtbegin.o(.dtors))
 134     KEEP (*crtbegin?.o(.dtors))
 135     KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o $OTHER_EXCLUDE_FILES) .dtors))
 136     KEEP (*(SORT(.dtors.*)))
 137     KEEP (*(.dtors))
 138     ${CONSTRUCTING+${DTOR_END}}
 139 "
 140 STACK="  .stack        ${RELOCATING-0}${RELOCATING+${STACK_ADDR}} :
 141   {
 142     ${RELOCATING+_stack = .;}
 143     *(.stack)
 144   }"
 145
 146 test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR}"
 147
 148 cat <<EOF
 149 OUTPUT_FORMAT("${OUTPUT_FORMAT}", "${BIG_OUTPUT_FORMAT}",
 150               "${LITTLE_OUTPUT_FORMAT}")
 151 OUTPUT_ARCH(${OUTPUT_ARCH})
 152 ENTRY(${ENTRY})
 153
 154 ${RELOCATING+${LIB_SEARCH_DIRS}}
 155 ${RELOCATING+/* Do we need any of these for elf?
 156    __DYNAMIC = 0; ${STACKZERO+${STACKZERO}} ${SHLIB_PATH+${SHLIB_PATH}}  */}
 157 ${RELOCATING+${EXECUTABLE_SYMBOLS}}
 158 ${RELOCATING+${INPUT_FILES}}
 159 ${RELOCATING- /* For some reason, the Solaris linker makes bad executables
 160   if gld -r is used and the intermediate file has sections starting
 161   at non-zero addresses.  Could be a Solaris ld bug, could be a GNU ld
 162   bug.  But for now assigning the zero vmas works.  */}
 163
 164 SECTIONS
 165 {
 166   /* Read-only sections, merged into text segment: */
 167   ${CREATE_SHLIB-${RELOCATING+. = ${TEXT_BASE_ADDRESS};}}
 168   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_TEXT_START_ADDR:-0};}}
 169   ${CREATE_SHLIB-${INTERP}}
 170   ${INITIAL_READONLY_SECTIONS}
 171   ${TEXT_DYNAMIC+${DYNAMIC}}
 172   .hash         ${RELOCATING-0} : { *(.hash) }
 173   .dynsym       ${RELOCATING-0} : { *(.dynsym) }
 174   .dynstr       ${RELOCATING-0} : { *(.dynstr) }
 175   .gnu.version  ${RELOCATING-0} : { *(.gnu.version) }
 176   .gnu.version_d ${RELOCATING-0}: { *(.gnu.version_d) }
 177   .gnu.version_r ${RELOCATING-0}: { *(.gnu.version_r) }
 178
 179 EOF
 180 if [ "x$COMBRELOC" = x ]; then
 181   COMBRELOCCAT=cat
 182 else
 183   COMBRELOCCAT="cat > $COMBRELOC"
 184 fi
 185 eval $COMBRELOCCAT <<EOF
 186   .rel.init     ${RELOCATING-0} : { *(.rel.init) }
 187   .rela.init    ${RELOCATING-0} : { *(.rela.init) }
 188   .rel.text     ${RELOCATING-0} : { *(.rel.text${RELOCATING+ .rel.text.* .rel.gnu.linkonce.t.*}) }
 189   .rela.text    ${RELOCATING-0} : { *(.rela.text${RELOCATING+ .rela.text.* .rela.gnu.linkonce.t.*}) }
 190   .rel.fini     ${RELOCATING-0} : { *(.rel.fini) }
 191   .rela.fini    ${RELOCATING-0} : { *(.rela.fini) }
 192   .rel.rodata   ${RELOCATING-0} : { *(.rel.rodata${RELOCATING+ .rel.rodata.* .rel.gnu.linkonce.r.*}) }
 193   .rela.rodata  ${RELOCATING-0} : { *(.rela.rodata${RELOCATING+ .rela.rodata.* .rela.gnu.linkonce.r.*}) }
 194   ${OTHER_READONLY_RELOC_SECTIONS}
 195   .rel.data     ${RELOCATING-0} : { *(.rel.data${RELOCATING+ .rel.data.* .rel.gnu.linkonce.d.*}) }
 196   .rela.data    ${RELOCATING-0} : { *(.rela.data${RELOCATING+ .rela.data.* .rela.gnu.linkonce.d.*}) }
 197   .rel.ctors    ${RELOCATING-0} : { *(.rel.ctors) }
 198   .rela.ctors   ${RELOCATING-0} : { *(.rela.ctors) }
 199   .rel.dtors    ${RELOCATING-0} : { *(.rel.dtors) }
 200   .rela.dtors   ${RELOCATING-0} : { *(.rela.dtors) }
 201   .rel.got      ${RELOCATING-0} : { *(.rel.got) }
 202   .rela.got     ${RELOCATING-0} : { *(.rela.got) }
 203   ${OTHER_GOT_RELOC_SECTIONS}
 204   ${REL_SDATA}
 205   ${REL_SBSS}
 206   ${REL_SDATA2}
 207   ${REL_SBSS2}
 208   .rel.bss      ${RELOCATING-0} : { *(.rel.bss${RELOCATING+ .rel.bss.* .rel.gnu.linkonce.b.*}) }
 209   .rela.bss     ${RELOCATING-0} : { *(.rela.bss${RELOCATING+ .rela.bss.* .rela.gnu.linkonce.b.*}) }
 210 EOF
 211 if [ -n "$COMBRELOC" ]; then
 212 cat <<EOF
 213   .rel.dyn      ${RELOCATING-0} :
 214     {
 215 EOF
 216 sed -e '/^[     ]*[{}][         ]*$/d;/:[       ]*$/d;/\.rela\./d;s/^.*: { *\(.*\)}$/      \1/' $COMBRELOC
 217 cat <<EOF
 218     }
 219   .rela.dyn     ${RELOCATING-0} :
 220     {
 221 EOF
 222 sed -e '/^[     ]*[{}][         ]*$/d;/:[       ]*$/d;/\.rel\./d;s/^.*: { *\(.*\)}/      \1/' $COMBRELOC
 223 cat <<EOF
 224     }
 225 EOF
 226 fi
 227 cat <<EOF
 228   . = ALIGN(0x1000);
 229   .rel.plt      ${RELOCATING-0} : { *(.rel.plt) }
 230   .rela.plt     ${RELOCATING-0} : { *(.rela.plt) }
 231   ${OTHER_PLT_RELOC_SECTIONS}
 232   ${DATA_PLT-${BSS_PLT-${PLT}}}
 233   .text         ${RELOCATING-0} :
 234   {
 235     ${RELOCATING+${TEXT_START_SYMBOLS}}
 236     *(.text .stub${RELOCATING+ .text.* .gnu.linkonce.t.*})
 237     /* .gnu.warning sections are handled specially by elf32.em.  */
 238     *(.gnu.warning)
 239     ${RELOCATING+${OTHER_TEXT_SECTIONS}}
 240   } =${NOP-0}
 241   .fini         ${RELOCATING-0} :
 242   {
 243     ${RELOCATING+${FINI_START}}
 244     KEEP (*(.fini))
 245     ${RELOCATING+${FINI_END}}
 246   } =${NOP-0}
 247   ${RELOCATING+PROVIDE (__etext = .);}
 248   ${RELOCATING+PROVIDE (_etext = .);}
 249   ${RELOCATING+PROVIDE (etext = .);}
 250   . = ALIGN(0x1000);
 251   ${CREATE_SHLIB-${SDATA2}}
 252   ${CREATE_SHLIB-${SBSS2}}
 253   ${OTHER_READONLY_SECTIONS}
 254   .eh_frame_hdr : { *(.eh_frame_hdr) }
 255
 256   . = ALIGN(0x1000);
 257   .data         ${RELOCATING-0} :
 258   {
 259     *(.rodata .rodata.*)
 260     *(.rodata1)
 261     *(.gnu.linkonce.r.*)
 262     ${RELOCATING+${DATA_START_SYMBOLS}}
 263     *(.data${RELOCATING+ .data.* .gnu.linkonce.d.*})
 264     ${CONSTRUCTING+SORT(CONSTRUCTORS)}
 265     KEEP (*(.eh_frame))
 266     *(.gcc_except_table)
 267     ${CTOR}
 268     ${DTOR}
 269     KEEP (*(.jcr))
 270   }
 271   .data1        ${RELOCATING-0} : { *(.data1) }
 272   . = ALIGN(0x1000);
 273   .gcc_except_table ${RELOCATING-0} : { *(.gcc_except_table) }
 274   ${WRITABLE_RODATA+${RODATA}}
 275   ${OTHER_READWRITE_SECTIONS}
 276   ${TEXT_DYNAMIC-${DYNAMIC}}
 277   ${DATA_PLT+${PLT}}
 278   ${RELOCATING+${OTHER_GOT_SYMBOLS}}
 279   .got          ${RELOCATING-0} : { *(.got.plt) *(.got) }
 280   ${OTHER_GOT_SECTIONS}
 281   ${CREATE_SHLIB+${SDATA2}}
 282   ${CREATE_SHLIB+${SBSS2}}
 283   ${SDATA}
 284   ${OTHER_SDATA_SECTIONS}
 285   ${RELOCATING+_edata = .;}
 286   ${RELOCATING+PROVIDE (edata = .);}
 287   ${RELOCATING+__bss_start = .;}
 288   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
 289   ${SBSS}
 290   ${BSS_PLT+${PLT}}
 291   . = ALIGN(0x1000);
 292   .bss          ${RELOCATING-0} :
 293   {
 294    *(.dynbss)
 295    *(.bss${RELOCATING+ .bss.* .gnu.linkonce.b.*})
 296    *(COMMON)
 297    /* Align here to ensure that the .bss section occupies space up to
 298       _end.  Align after .bss to ensure correct alignment even if the
 299       .bss section disappears because there are no input sections.  */
 300    ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 301   }
 302   ${RELOCATING+${OTHER_BSS_END_SYMBOLS}}
 303   ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 304   ${RELOCATING+${OTHER_END_SYMBOLS}}
 305   ${RELOCATING+_end = .;}
 306   ${RELOCATING+PROVIDE (end = .);}
 307
 308   /* Stabs debugging sections.  */
 309   . = ALIGN(0x1000);
 310   .stab          0 : { *(.stab) }
 311   .stabstr       0 : { *(.stabstr) }
 312   .stab.excl     0 : { *(.stab.excl) }
 313   .stab.exclstr  0 : { *(.stab.exclstr) }
 314   .stab.index    0 : { *(.stab.index) }
 315   .stab.indexstr 0 : { *(.stab.indexstr) }
 316
 317   . = ALIGN(0x1000);
 318   .comment       0 : { *(.comment) }
 319
 320   /* DWARF debug sections.
 321      Symbols in the DWARF debugging sections are relative to the beginning
 322      of the section so we begin them at 0.  */
 323
 324   /* DWARF 1 */
 325   .debug          0 : { *(.debug) }
 326   .line           0 : { *(.line) }
 327
 328   /* GNU DWARF 1 extensions */
 329   .debug_srcinfo  0 : { *(.debug_srcinfo) }
 330   .debug_sfnames  0 : { *(.debug_sfnames) }
 331
 332   /* DWARF 1.1 and DWARF 2 */
 333   .debug_aranges  0 : { *(.debug_aranges) }
 334   .debug_pubnames 0 : { *(.debug_pubnames) }
 335
 336   /* DWARF 2 */
 337   .debug_info     0 : { *(.debug_info .gnu.linkonce.wi.*) }
 338   .debug_abbrev   0 : { *(.debug_abbrev) }
 339   .debug_line     0 : { *(.debug_line) }
 340   .debug_frame    0 : { *(.debug_frame) }
 341   .debug_str      0 : { *(.debug_str) }
 342   .debug_loc      0 : { *(.debug_loc) }
 343   .debug_macinfo  0 : { *(.debug_macinfo) }
 344
 345   /* SGI/MIPS DWARF 2 extensions */
 346   .debug_weaknames 0 : { *(.debug_weaknames) }
 347   .debug_funcnames 0 : { *(.debug_funcnames) }
 348   .debug_typenames 0 : { *(.debug_typenames) }
 349   .debug_varnames  0 : { *(.debug_varnames) }
 350
 351   ${STACK_ADDR+${STACK}}
 352   ${OTHER_SECTIONS}
 353   ${RELOCATING+${OTHER_SYMBOLS}}
 354 }
 355 EOF