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 #       ATTRS_SECTIONS - at the end
  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_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 -z "$ATTRS_SECTIONS" && ATTRS_SECTIONS=".gnu.attributes 0 : { KEEP (*(.gnu.attributes)) }"
  73 test "$LD_FLAG" = "N" && DATA_ADDR=.
  74 INTERP=".interp       ${RELOCATING-0} : { *(.interp) }"
  75 PLT=".plt          ${RELOCATING-0} : { *(.plt) }"
  76 DYNAMIC=".dynamic      ${RELOCATING-0} : { *(.dynamic) }"
  77 RODATA=".rodata       ${RELOCATING-0} : { *(.rodata${RELOCATING+ .rodata.* .gnu.linkonce.r.*}) }"
  78 if test -z "${NO_SMALL_DATA}"; then
  79   SBSS=".sbss         ${RELOCATING-0} :
  80   {
  81     ${RELOCATING+PROVIDE (__sbss_start = .);}
  82     ${RELOCATING+PROVIDE (___sbss_start = .);}
  83     *(.dynsbss)
  84     *(.sbss${RELOCATING+ .sbss.* .gnu.linkonce.sb.*})
  85     *(.scommon)
  86     ${RELOCATING+PROVIDE (__sbss_end = .);}
  87     ${RELOCATING+PROVIDE (___sbss_end = .);}
  88   }"
  89   SBSS2=".sbss2        ${RELOCATING-0} : { *(.sbss2${RELOCATING+ .sbss2.* .gnu.linkonce.sb2.*}) }"
  90   SDATA="/* We want the small data sections together, so single-instruction offsets
  91      can access them all, and initialized data all before uninitialized, so
  92      we can shorten the on-disk segment size.  */
  93   .sdata        ${RELOCATING-0} :
  94   {
  95     ${RELOCATING+${SDATA_START_SYMBOLS}}
  96     *(.sdata${RELOCATING+ .sdata.* .gnu.linkonce.s.*})
  97   }"
  98   SDATA2=".sdata2       ${RELOCATING-0} : { *(.sdata2${RELOCATING+ .sdata2.* .gnu.linkonce.s2.*}) }"
  99   REL_SDATA=".rel.sdata    ${RELOCATING-0} : { *(.rel.sdata${RELOCATING+ .rel.sdata.* .rel.gnu.linkonce.s.*}) }
 100   .rela.sdata   ${RELOCATING-0} : { *(.rela.sdata${RELOCATING+ .rela.sdata.* .rela.gnu.linkonce.s.*}) }"
 101   REL_SBSS=".rel.sbss     ${RELOCATING-0} : { *(.rel.sbss${RELOCATING+ .rel.sbss.* .rel.gnu.linkonce.sb.*}) }
 102   .rela.sbss    ${RELOCATING-0} : { *(.rela.sbss${RELOCATING+ .rela.sbss.* .rela.gnu.linkonce.sb.*}) }"
 103   REL_SDATA2=".rel.sdata2   ${RELOCATING-0} : { *(.rel.sdata2${RELOCATING+ .rel.sdata2.* .rel.gnu.linkonce.s2.*}) }
 104   .rela.sdata2  ${RELOCATING-0} : { *(.rela.sdata2${RELOCATING+ .rela.sdata2.* .rela.gnu.linkonce.s2.*}) }"
 105   REL_SBSS2=".rel.sbss2    ${RELOCATING-0} : { *(.rel.sbss2${RELOCATING+ .rel.sbss2.* .rel.gnu.linkonce.sb2.*}) }
 106   .rela.sbss2   ${RELOCATING-0} : { *(.rela.sbss2${RELOCATING+ .rela.sbss2.* .rela.gnu.linkonce.sb2.*}) }"
 107 fi
 108 CTOR="
 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     KEEP (*crtbegin?.o(.ctors))
 122
 123     /* We don't want to include the .ctor section from
 124        the crtend.o file until after the sorted ctors.
 125        The .ctor section from the crtend file contains the
 126        end of ctors marker and it must be last */
 127
 128     KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o $OTHER_EXCLUDE_FILES) .ctors))
 129     KEEP (*(SORT(.ctors.*)))
 130     KEEP (*(.ctors))
 131     ${CONSTRUCTING+${CTOR_END}}
 132 "
 133 DTOR="
 134     ${CONSTRUCTING+${DTOR_START}}
 135     KEEP (*crtbegin.o(.dtors))
 136     KEEP (*crtbegin?.o(.dtors))
 137     KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o $OTHER_EXCLUDE_FILES) .dtors))
 138     KEEP (*(SORT(.dtors.*)))
 139     KEEP (*(.dtors))
 140     ${CONSTRUCTING+${DTOR_END}}
 141 "
 142 STACK="  .stack        ${RELOCATING-0}${RELOCATING+${STACK_ADDR}} :
 143   {
 144     ${RELOCATING+_stack = .;}
 145     *(.stack)
 146   }"
 147
 148 test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR}"
 149
 150 cat <<EOF
 151 OUTPUT_FORMAT("${OUTPUT_FORMAT}", "${BIG_OUTPUT_FORMAT}",
 152               "${LITTLE_OUTPUT_FORMAT}")
 153 OUTPUT_ARCH(${OUTPUT_ARCH})
 154 ENTRY(${ENTRY})
 155
 156 ${RELOCATING+${LIB_SEARCH_DIRS}}
 157 ${RELOCATING+/* Do we need any of these for elf?
 158    __DYNAMIC = 0; ${STACKZERO+${STACKZERO}} ${SHLIB_PATH+${SHLIB_PATH}}  */}
 159 ${RELOCATING+${EXECUTABLE_SYMBOLS}}
 160 ${RELOCATING+${INPUT_FILES}}
 161 ${RELOCATING- /* For some reason, the Solaris linker makes bad executables
 162   if gld -r is used and the intermediate file has sections starting
 163   at non-zero addresses.  Could be a Solaris ld bug, could be a GNU ld
 164   bug.  But for now assigning the zero vmas works.  */}
 165
 166 SECTIONS
 167 {
 168   /* Read-only sections, merged into text segment: */
 169   ${CREATE_SHLIB-${RELOCATING+. = ${TEXT_BASE_ADDRESS};}}
 170   ${CREATE_SHLIB+${RELOCATING+. = ${SHLIB_TEXT_START_ADDR:-0};}}
 171   ${CREATE_SHLIB-${INTERP}}
 172   ${INITIAL_READONLY_SECTIONS}
 173   ${TEXT_DYNAMIC+${DYNAMIC}}
 174   .hash         ${RELOCATING-0} : { *(.hash) }
 175   .dynsym       ${RELOCATING-0} : { *(.dynsym) }
 176   .dynstr       ${RELOCATING-0} : { *(.dynstr) }
 177   .gnu.version  ${RELOCATING-0} : { *(.gnu.version) }
 178   .gnu.version_d ${RELOCATING-0}: { *(.gnu.version_d) }
 179   .gnu.version_r ${RELOCATING-0}: { *(.gnu.version_r) }
 180
 181 EOF
 182 if [ "x$COMBRELOC" = x ]; then
 183   COMBRELOCCAT=cat
 184 else
 185   COMBRELOCCAT="cat > $COMBRELOC"
 186 fi
 187 eval $COMBRELOCCAT <<EOF
 188   .rel.init     ${RELOCATING-0} : { *(.rel.init) }
 189   .rela.init    ${RELOCATING-0} : { *(.rela.init) }
 190   .rel.text     ${RELOCATING-0} : { *(.rel.text${RELOCATING+ .rel.text.* .rel.gnu.linkonce.t.*}) }
 191   .rela.text    ${RELOCATING-0} : { *(.rela.text${RELOCATING+ .rela.text.* .rela.gnu.linkonce.t.*}) }
 192   .rel.fini     ${RELOCATING-0} : { *(.rel.fini) }
 193   .rela.fini    ${RELOCATING-0} : { *(.rela.fini) }
 194   .rel.rodata   ${RELOCATING-0} : { *(.rel.rodata${RELOCATING+ .rel.rodata.* .rel.gnu.linkonce.r.*}) }
 195   .rela.rodata  ${RELOCATING-0} : { *(.rela.rodata${RELOCATING+ .rela.rodata.* .rela.gnu.linkonce.r.*}) }
 196   ${OTHER_READONLY_RELOC_SECTIONS}
 197   .rel.data     ${RELOCATING-0} : { *(.rel.data${RELOCATING+ .rel.data.* .rel.gnu.linkonce.d.*}) }
 198   .rela.data    ${RELOCATING-0} : { *(.rela.data${RELOCATING+ .rela.data.* .rela.gnu.linkonce.d.*}) }
 199   .rel.ctors    ${RELOCATING-0} : { *(.rel.ctors) }
 200   .rela.ctors   ${RELOCATING-0} : { *(.rela.ctors) }
 201   .rel.dtors    ${RELOCATING-0} : { *(.rel.dtors) }
 202   .rela.dtors   ${RELOCATING-0} : { *(.rela.dtors) }
 203   .rel.got      ${RELOCATING-0} : { *(.rel.got) }
 204   .rela.got     ${RELOCATING-0} : { *(.rela.got) }
 205   ${OTHER_GOT_RELOC_SECTIONS}
 206   ${REL_SDATA}
 207   ${REL_SBSS}
 208   ${REL_SDATA2}
 209   ${REL_SBSS2}
 210   .rel.bss      ${RELOCATING-0} : { *(.rel.bss${RELOCATING+ .rel.bss.* .rel.gnu.linkonce.b.*}) }
 211   .rela.bss     ${RELOCATING-0} : { *(.rela.bss${RELOCATING+ .rela.bss.* .rela.gnu.linkonce.b.*}) }
 212 EOF
 213 if [ -n "$COMBRELOC" ]; then
 214 cat <<EOF
 215   .rel.dyn      ${RELOCATING-0} :
 216     {
 217 EOF
 218 sed -e '/^[     ]*[{}][         ]*$/d;/:[       ]*$/d;/\.rela\./d;s/^.*: { *\(.*\)}$/      \1/' $COMBRELOC
 219 cat <<EOF
 220     }
 221   .rela.dyn     ${RELOCATING-0} :
 222     {
 223 EOF
 224 sed -e '/^[     ]*[{}][         ]*$/d;/:[       ]*$/d;/\.rel\./d;s/^.*: { *\(.*\)}/      \1/' $COMBRELOC
 225 cat <<EOF
 226     }
 227 EOF
 228 fi
 229 cat <<EOF
 230   . = ALIGN(0x1000);
 231   .rel.plt      ${RELOCATING-0} : { *(.rel.plt) }
 232   .rela.plt     ${RELOCATING-0} : { *(.rela.plt) }
 233   ${OTHER_PLT_RELOC_SECTIONS}
 234   ${DATA_PLT-${BSS_PLT-${PLT}}}
 235   .text         ${RELOCATING-0} :
 236   {
 237     ${RELOCATING+${TEXT_START_SYMBOLS}}
 238     *(.text .stub${RELOCATING+ .text.* .gnu.linkonce.t.*})
 239     /* .gnu.warning sections are handled specially by elf32.em.  */
 240     *(.gnu.warning)
 241     ${RELOCATING+${OTHER_TEXT_SECTIONS}}
 242   } =${NOP-0}
 243   .fini         ${RELOCATING-0} :
 244   {
 245     ${RELOCATING+${FINI_START}}
 246     KEEP (*(.fini))
 247     ${RELOCATING+${FINI_END}}
 248   } =${NOP-0}
 249   ${RELOCATING+PROVIDE (__etext = .);}
 250   ${RELOCATING+PROVIDE (_etext = .);}
 251   ${RELOCATING+PROVIDE (etext = .);}
 252   . = ALIGN(0x1000);
 253   ${CREATE_SHLIB-${SDATA2}}
 254   ${CREATE_SHLIB-${SBSS2}}
 255   ${OTHER_READONLY_SECTIONS}
 256   .eh_frame_hdr : { *(.eh_frame_hdr) }
 257
 258   . = ALIGN(0x1000);
 259   .data         ${RELOCATING-0} :
 260   {
 261     *(.rodata .rodata.*)
 262     *(.rodata1)
 263     *(.gnu.linkonce.r.*)
 264     ${RELOCATING+${DATA_START_SYMBOLS}}
 265     *(.data${RELOCATING+ .data.* .gnu.linkonce.d.*})
 266     ${CONSTRUCTING+SORT(CONSTRUCTORS)}
 267     KEEP (*(.eh_frame))
 268     *(.gcc_except_table)
 269     ${CTOR}
 270     ${DTOR}
 271     KEEP (*(.jcr))
 272   }
 273   .data1        ${RELOCATING-0} : { *(.data1) }
 274   . = ALIGN(0x1000);
 275   .gcc_except_table ${RELOCATING-0} : { *(.gcc_except_table) }
 276   ${WRITABLE_RODATA+${RODATA}}
 277   ${OTHER_READWRITE_SECTIONS}
 278   ${TEXT_DYNAMIC-${DYNAMIC}}
 279   ${DATA_PLT+${PLT}}
 280   ${RELOCATING+${OTHER_GOT_SYMBOLS}}
 281   .got          ${RELOCATING-0} : { *(.got.plt) *(.got) }
 282   ${OTHER_GOT_SECTIONS}
 283   ${CREATE_SHLIB+${SDATA2}}
 284   ${CREATE_SHLIB+${SBSS2}}
 285   ${SDATA}
 286   ${OTHER_SDATA_SECTIONS}
 287   ${RELOCATING+_edata = .;}
 288   ${RELOCATING+PROVIDE (edata = .);}
 289   ${RELOCATING+__bss_start = .;}
 290   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
 291   ${SBSS}
 292   ${BSS_PLT+${PLT}}
 293   . = ALIGN(0x1000);
 294   .bss          ${RELOCATING-0} :
 295   {
 296    *(.dynbss)
 297    *(.bss${RELOCATING+ .bss.* .gnu.linkonce.b.*})
 298    *(COMMON)
 299    /* Align here to ensure that the .bss section occupies space up to
 300       _end.  Align after .bss to ensure correct alignment even if the
 301       .bss section disappears because there are no input sections.  */
 302    ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 303   }
 304   ${RELOCATING+${OTHER_BSS_END_SYMBOLS}}
 305   ${RELOCATING+. = ALIGN(${ALIGNMENT});}
 306   ${RELOCATING+${OTHER_END_SYMBOLS}}
 307   ${RELOCATING+_end = .;}
 308   ${RELOCATING+PROVIDE (end = .);}
 309
 310   /* Stabs debugging sections.  */
 311   . = ALIGN(0x1000);
 312   .stab          0 : { *(.stab) }
 313   .stabstr       0 : { *(.stabstr) }
 314   .stab.excl     0 : { *(.stab.excl) }
 315   .stab.exclstr  0 : { *(.stab.exclstr) }
 316   .stab.index    0 : { *(.stab.index) }
 317   .stab.indexstr 0 : { *(.stab.indexstr) }
 318
 319   . = ALIGN(0x1000);
 320   .comment       0 : { *(.comment) }
 321
 322   /* DWARF debug sections.
 323      Symbols in the DWARF debugging sections are relative to the beginning
 324      of the section so we begin them at 0.  */
 325
 326   /* DWARF 1 */
 327   .debug          0 : { *(.debug) }
 328   .line           0 : { *(.line) }
 329
 330   /* GNU DWARF 1 extensions */
 331   .debug_srcinfo  0 : { *(.debug_srcinfo) }
 332   .debug_sfnames  0 : { *(.debug_sfnames) }
 333
 334   /* DWARF 1.1 and DWARF 2 */
 335   .debug_aranges  0 : { *(.debug_aranges) }
 336   .debug_pubnames 0 : { *(.debug_pubnames) }
 337
 338   /* DWARF 2 */
 339   .debug_info     0 : { *(.debug_info .gnu.linkonce.wi.*) }
 340   .debug_abbrev   0 : { *(.debug_abbrev) }
 341   .debug_line     0 : { *(.debug_line) }
 342   .debug_frame    0 : { *(.debug_frame) }
 343   .debug_str      0 : { *(.debug_str) }
 344   .debug_loc      0 : { *(.debug_loc) }
 345   .debug_macinfo  0 : { *(.debug_macinfo) }
 346
 347   /* SGI/MIPS DWARF 2 extensions */
 348   .debug_weaknames 0 : { *(.debug_weaknames) }
 349   .debug_funcnames 0 : { *(.debug_funcnames) }
 350   .debug_typenames 0 : { *(.debug_typenames) }
 351   .debug_varnames  0 : { *(.debug_varnames) }
 352
 353   ${STACK_ADDR+${STACK}}
 354   ${ATTRS_SECTIONS}
 355   ${OTHER_SECTIONS}
 356   ${RELOCATING+${OTHER_SYMBOLS}}
 357 }
 358 EOF