# Copyright (C) 2014-2024 Free Software Foundation, Inc. # # Copying and distribution of this file, with or without modification, # are permitted in any medium without royalty provided the copyright # notice and this notice are preserved. # # Unusual variables checked by this code: # NOP - four byte opcode for no-op (defaults to none) # NO_SMALL_DATA - no .sbss/.sbss2/.sdata/.sdata2 sections if not # empty. # HAVE_NOINIT - Include a .noinit output section in the script. # HAVE_PERSISTENT - Include a .persistent output section in the script. # HAVE_DT_RELR - Include a .relr.dyn output section in the script. # SMALL_DATA_CTOR - .ctors contains small data. # SMALL_DATA_DTOR - .dtors contains small data. # DATA_ADDR - if end-of-text-plus-one-page isn't right for data start # INITIAL_READONLY_SECTIONS - at start of text segment # OTHER_READONLY_SECTIONS - other than .text .init .rodata ... # (e.g., .PARISC.milli) # OTHER_TEXT_SECTIONS - these get put in .text when relocating # INITIAL_READWRITE_SECTIONS - at start of data segment (after relro) # OTHER_READWRITE_SECTIONS - other than .data .bss .ctors .sdata ... # (e.g., .PARISC.global) # OTHER_RELRO_SECTIONS - other than .data.rel.ro ... # (e.g. PPC32 .fixup, .got[12]) # OTHER_RELRO_SECTIONS_2 - as above, but after .dynamic in text segment # OTHER_BSS_SECTIONS - other than .bss .sbss ... # ATTRS_SECTIONS - at the end # OTHER_SECTIONS - at the end # EXECUTABLE_SYMBOLS - symbols that must be defined for an # executable (e.g., _DYNAMIC_LINK) # TEXT_START_ADDR - the first byte of the text segment, after any # headers. # TEXT_BASE_ADDRESS - the first byte of the text segment. # TEXT_START_SYMBOLS - symbols that appear at the start of the # .text section. # DATA_START_SYMBOLS - symbols that appear at the start of the # .data section. # DATA_END_SYMBOLS - symbols that appear at the end of the # writeable data sections. # OTHER_GOT_SYMBOLS - symbols defined just before .got. # OTHER_GOT_SECTIONS - sections just after .got. # OTHER_PLT_SECTIONS - sections just after .plt. # OTHER_SDATA_SECTIONS - sections just after .sdata. # OTHER_BSS_SYMBOLS - symbols that appear at the start of the # .bss section besides __bss_start. # PLT_NEXT_DATA - .plt next to data segment when .plt is in text segment. # DATA_PLT - .plt should be in data segment, not text segment. # PLT_BEFORE_GOT - .plt just before .got when .plt is in data segement. # BSS_PLT - .plt should be in bss segment # NO_REL_RELOCS - Don't include .rel.* sections in script # NO_RELA_RELOCS - Don't include .rela.* sections in script # NON_ALLOC_DYN - Place dynamic sections after data segment. # TEXT_DYNAMIC - .dynamic in text segment, not data segment. # EMBEDDED - whether this is for an embedded system. # SHLIB_TEXT_START_ADDR - if set, add to SIZEOF_HEADERS to set # start address of shared library. # INPUT_FILES - INPUT command of files to always include # WRITABLE_RODATA - if set, the .rodata section should be writable # INIT_START, INIT_END - statements just before and just after # combination of .init sections. # FINI_START, FINI_END - statements just before and just after # combination of .fini sections. # STACK_ADDR - start of a .stack section. # OTHER_SYMBOLS - symbols to place right at the end of the script. # ETEXT_NAME - name of a symbol for the end of the text section, # normally etext. # ETEXT_LAST_IN_RODATA_SEGMENT - emit ETEXT_NAME after all sections in # the read-only data segment (which may or may not be equal to # the code segment), instead of after just the code parts. # SEPARATE_CODE - if set, .text and similar sections containing # actual machine instructions must be in wholly disjoint # pages from any other data, including headers # SEPARATE_GOTPLT - if set, .got.plt should be separate output section, # so that .got can be in the RELRO area. It should be set to # the number of bytes in the beginning of .got.plt which can be # in the RELRO area as well. # USER_LABEL_PREFIX - prefix to add to user-visible symbols. # RODATA_NAME, SDATA_NAME, SBSS_NAME, BSS_NAME - base parts of names # for standard sections, without initial "." or suffixes. # SYMBOL_ABI_ALIGNMENT - minimum alignment in bytes which needs to be # applied to every symbol definition # ALL_TEXT_BEFORE_RO - put all code sections before read-only # sections # # When adding sections, do note that the names of some sections are used # when specifying the start address of the next. # # Many sections come in three flavours. There is the 'real' section, # like ".data". Then there are the per-procedure or per-variable # sections, generated by -ffunction-sections and -fdata-sections in GCC, # and useful for --gc-sections, which for a variable "foo" might be # ".data.foo". Then there are the linkonce sections, for which the linker # eliminates duplicates, which are named like ".gnu.linkonce.d.foo". # The exact correspondences are: # # Section Linkonce section # .text .gnu.linkonce.t.foo # .rodata .gnu.linkonce.r.foo # .data .gnu.linkonce.d.foo # .bss .gnu.linkonce.b.foo # .sdata .gnu.linkonce.s.foo # .sbss .gnu.linkonce.sb.foo # .sdata2 .gnu.linkonce.s2.foo # .sbss2 .gnu.linkonce.sb2.foo # .debug_info .gnu.linkonce.wi.foo # .tdata .gnu.linkonce.td.foo # .tbss .gnu.linkonce.tb.foo # .lrodata .gnu.linkonce.lr.foo # .ldata .gnu.linkonce.l.foo # .lbss .gnu.linkonce.lb.foo # .noinit .gnu.linkonce.n.foo # .persistent .gnu.linkonce.p.foo # # Each of these can also have corresponding .rel.* and .rela.* sections. if test -n "$NOP"; then FILL="=$NOP" else FILL= fi test -n "$CREATE_SHLIB$CREATE_PIE" && CREATE_PIC=" " test -z "$RODATA_NAME" && RODATA_NAME=rodata test -z "$SDATA_NAME" && SDATA_NAME=sdata test -z "$SBSS_NAME" && SBSS_NAME=sbss test -z "$BSS_NAME" && BSS_NAME=bss test -z "$ENTRY" && ENTRY=${USER_LABEL_PREFIX}_start test -z "${BIG_OUTPUT_FORMAT}" && BIG_OUTPUT_FORMAT=${OUTPUT_FORMAT} test -z "${LITTLE_OUTPUT_FORMAT}" && LITTLE_OUTPUT_FORMAT=${OUTPUT_FORMAT} if [ -z "$MACHINE" ]; then OUTPUT_ARCH=${ARCH}; else OUTPUT_ARCH=${ARCH}:${MACHINE}; fi test -z "${ELFSIZE}" && ELFSIZE=32 test -z "${ALIGNMENT}" && ALIGNMENT="${ELFSIZE} / 8" test "$LD_FLAG" = "N" && DATA_ADDR=. test -z "${ETEXT_NAME}" && ETEXT_NAME=${USER_LABEL_PREFIX}etext test -n "$RELRO_NOW" && unset SEPARATE_GOTPLT test -z "$ATTRS_SECTIONS" && ATTRS_SECTIONS=".gnu.attributes 0 : { KEEP (*(.gnu.attributes)) }" if test -z "$DATA_SEGMENT_ALIGN"; then test -n "$CREATE_SHLIB$CREATE_PIE" && test -n "$SHLIB_DATA_ADDR" && COMMONPAGESIZE="" test -z "$CREATE_SHLIB$CREATE_PIE" && test -n "$DATA_ADDR" && COMMONPAGESIZE="" DATA_SEGMENT_ALIGN="ALIGN(${SEGMENT_SIZE}) + (. & (${MAXPAGESIZE} - 1))" DATA_SEGMENT_RELRO_END="" DATA_SEGMENT_END="" if test -n "${COMMONPAGESIZE}"; then if test "${SEGMENT_SIZE}" != "${MAXPAGESIZE}"; then DATA_SEGMENT_ALIGN="ALIGN (${SEGMENT_SIZE}) - ((${MAXPAGESIZE} - .) & (${MAXPAGESIZE} - 1)); . = DATA_SEGMENT_ALIGN (${MAXPAGESIZE}, ${COMMONPAGESIZE})" else DATA_SEGMENT_ALIGN="DATA_SEGMENT_ALIGN (${MAXPAGESIZE}, ${COMMONPAGESIZE})" fi DATA_SEGMENT_END=". = DATA_SEGMENT_END (.);" DATA_SEGMENT_RELRO_END=". = DATA_SEGMENT_RELRO_END (${SEPARATE_GOTPLT-0}, .);" fi fi if test -z "${INITIAL_READONLY_SECTIONS}${CREATE_SHLIB}"; then INITIAL_READONLY_SECTIONS=".interp ${RELOCATING-0} : { *(.interp) }" fi if test -z "$PLT"; then IPLT=".iplt ${RELOCATING-0} : { *(.iplt) }" PLT=".plt ${RELOCATING-0} : { *(.plt)${RELOCATING+${IREL_IN_PLT+ *(.iplt)}} } ${IREL_IN_PLT-$IPLT}" fi test -n "${DATA_PLT-${BSS_PLT-text}}" && TEXT_PLT= if test -z "$GOT"; then if test -z "$SEPARATE_GOTPLT"; then GOT=".got ${RELOCATING-0} : {${RELOCATING+ *(.got.plt) *(.igot.plt)} *(.got)${RELOCATING+ *(.igot)} }" else GOT=".got ${RELOCATING-0} : { *(.got)${RELOCATING+ *(.igot)} }" GOTPLT=".got.plt ${RELOCATING-0} : { *(.got.plt)${RELOCATING+ *(.igot.plt)} }" fi fi def_symbol() { if [ -z "${SYMBOL_ABI_ALIGNMENT}" ]; then echo "${USER_LABEL_PREFIX}$1 = ." else echo "${USER_LABEL_PREFIX}$1 = ALIGN(${SYMBOL_ABI_ALIGNMENT})" fi } REL_IFUNC=".rel.ifunc ${RELOCATING-0} : { *(.rel.ifunc) }" RELA_IFUNC=".rela.ifunc ${RELOCATING-0} : { *(.rela.ifunc) }" REL_IPLT=".rel.iplt ${RELOCATING-0} : { ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rel_iplt_start"));}} *(.rel.iplt) ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rel_iplt_end"));}} }" RELA_IPLT=".rela.iplt ${RELOCATING-0} : { ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rela_iplt_start"));}} *(.rela.iplt) ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rela_iplt_end"));}} }" DYNAMIC=".dynamic ${RELOCATING-0} : { *(.dynamic) }" RODATA=".${RODATA_NAME} ${RELOCATING-0} : { *(.${RODATA_NAME}${RELOCATING+ .${RODATA_NAME}.* .gnu.linkonce.r.*}) }" DATARELRO=".data.rel.ro : { *(.data.rel.ro.local* .gnu.linkonce.d.rel.ro.local.*) *(.data.rel.ro .data.rel.ro.* .gnu.linkonce.d.rel.ro.*) }" DISCARDED="/DISCARD/ : { *(.note.GNU-stack) *(.gnu_debuglink) *(.gnu.lto_*) }" if test -z "${NO_SMALL_DATA}"; then SBSS=".${SBSS_NAME} ${RELOCATING-0} : { ${RELOCATING+${SBSS_START_SYMBOLS}} ${CREATE_SHLIB+*(.${SBSS_NAME}2 .${SBSS_NAME}2.* .gnu.linkonce.sb2.*)} ${RELOCATING+*(.dyn${SBSS_NAME})} *(.${SBSS_NAME}${RELOCATING+ .${SBSS_NAME}.* .gnu.linkonce.sb.*}) ${RELOCATING+*(.scommon)} ${RELOCATING+${SBSS_END_SYMBOLS}} }" SBSS2=".${SBSS_NAME}2 ${RELOCATING-0} : { *(.${SBSS_NAME}2${RELOCATING+ .${SBSS_NAME}2.* .gnu.linkonce.sb2.*}) }" SDATA="/* We want the small data sections together, so single-instruction offsets can access them all, and initialized data all before uninitialized, so we can shorten the on-disk segment size. */ .${SDATA_NAME} ${RELOCATING-0} : { ${RELOCATING+${SDATA_START_SYMBOLS}} ${CREATE_SHLIB+*(.${SDATA_NAME}2 .${SDATA_NAME}2.* .gnu.linkonce.s2.*)} *(.${SDATA_NAME}${RELOCATING+ .${SDATA_NAME}.* .gnu.linkonce.s.*}) }" SDATA2=".${SDATA_NAME}2 ${RELOCATING-0} : { ${RELOCATING+${SDATA2_START_SYMBOLS}} *(.${SDATA_NAME}2${RELOCATING+ .${SDATA_NAME}2.* .gnu.linkonce.s2.*}) }" REL_SDATA=".rel.${SDATA_NAME} ${RELOCATING-0} : { *(.rel.${SDATA_NAME}${RELOCATING+ .rel.${SDATA_NAME}.* .rel.gnu.linkonce.s.*}) } .rela.${SDATA_NAME} ${RELOCATING-0} : { *(.rela.${SDATA_NAME}${RELOCATING+ .rela.${SDATA_NAME}.* .rela.gnu.linkonce.s.*}) }" REL_SBSS=".rel.${SBSS_NAME} ${RELOCATING-0} : { *(.rel.${SBSS_NAME}${RELOCATING+ .rel.${SBSS_NAME}.* .rel.gnu.linkonce.sb.*}) } .rela.${SBSS_NAME} ${RELOCATING-0} : { *(.rela.${SBSS_NAME}${RELOCATING+ .rela.${SBSS_NAME}.* .rela.gnu.linkonce.sb.*}) }" REL_SDATA2=".rel.${SDATA_NAME}2 ${RELOCATING-0} : { *(.rel.${SDATA_NAME}2${RELOCATING+ .rel.${SDATA_NAME}2.* .rel.gnu.linkonce.s2.*}) } .rela.${SDATA_NAME}2 ${RELOCATING-0} : { *(.rela.${SDATA_NAME}2${RELOCATING+ .rela.${SDATA_NAME}2.* .rela.gnu.linkonce.s2.*}) }" REL_SBSS2=".rel.${SBSS_NAME}2 ${RELOCATING-0} : { *(.rel.${SBSS_NAME}2${RELOCATING+ .rel.${SBSS_NAME}2.* .rel.gnu.linkonce.sb2.*}) } .rela.${SBSS_NAME}2 ${RELOCATING-0} : { *(.rela.${SBSS_NAME}2${RELOCATING+ .rela.${SBSS_NAME}2.* .rela.gnu.linkonce.sb2.*}) }" else NO_SMALL_DATA=" " fi if test -z "${SDATA_GOT}${DATA_GOT}"; then if test -n "${NO_SMALL_DATA}"; then DATA_GOT=" " fi fi if test -z "${SDATA_GOT}${DATA_GOT}"; then if test -z "${NO_SMALL_DATA}"; then SDATA_GOT=" " fi fi test -n "$SEPARATE_GOTPLT" && SEPARATE_GOTPLT=" " test "${LARGE_SECTIONS}" = "yes" && REL_LARGE=" .rel.ldata ${RELOCATING-0} : { *(.rel.ldata${RELOCATING+ .rel.ldata.* .rel.gnu.linkonce.l.*}) } .rela.ldata ${RELOCATING-0} : { *(.rela.ldata${RELOCATING+ .rela.ldata.* .rela.gnu.linkonce.l.*}) } .rel.lbss ${RELOCATING-0} : { *(.rel.lbss${RELOCATING+ .rel.lbss.* .rel.gnu.linkonce.lb.*}) } .rela.lbss ${RELOCATING-0} : { *(.rela.lbss${RELOCATING+ .rela.lbss.* .rela.gnu.linkonce.lb.*}) } .rel.lrodata ${RELOCATING-0} : { *(.rel.lrodata${RELOCATING+ .rel.lrodata.* .rel.gnu.linkonce.lr.*}) } .rela.lrodata ${RELOCATING-0} : { *(.rela.lrodata${RELOCATING+ .rela.lrodata.* .rela.gnu.linkonce.lr.*}) }" test "${LARGE_SECTIONS}" = "yes" && LARGE_BSS=" .lbss ${RELOCATING-0} : { ${RELOCATING+*(.dynlbss)} *(.lbss${RELOCATING+ .lbss.* .gnu.linkonce.lb.*}) ${RELOCATING+*(LARGE_COMMON)} }" test "${LARGE_SECTIONS}" = "yes" && LARGE_SECTIONS=" .lrodata ${RELOCATING-0} ${RELOCATING+ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))} : { *(.lrodata${RELOCATING+ .lrodata.* .gnu.linkonce.lr.*}) } .ldata ${RELOCATING-0} ${RELOCATING+ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))} : { *(.ldata${RELOCATING+ .ldata.* .gnu.linkonce.l.*}) ${RELOCATING+. = ALIGN(. != 0 ? ${ALIGNMENT} : 1);} }" if test "${ENABLE_INITFINI_ARRAY}" = "yes"; then SORT_INIT_ARRAY="KEEP (*(SORT_BY_INIT_PRIORITY(.init_array.*) SORT_BY_INIT_PRIORITY(.ctors.*)))" SORT_FINI_ARRAY="KEEP (*(SORT_BY_INIT_PRIORITY(.fini_array.*) SORT_BY_INIT_PRIORITY(.dtors.*)))" CTORS_IN_INIT_ARRAY="EXCLUDE_FILE (*crtbegin.o *crtbegin?.o *crtend.o *crtend?.o $OTHER_EXCLUDE_FILES) .ctors" DTORS_IN_FINI_ARRAY="EXCLUDE_FILE (*crtbegin.o *crtbegin?.o *crtend.o *crtend?.o $OTHER_EXCLUDE_FILES) .dtors" else SORT_INIT_ARRAY="KEEP (*(SORT(.init_array.*)))" SORT_FINI_ARRAY="KEEP (*(SORT(.fini_array.*)))" CTORS_IN_INIT_ARRAY= DTORS_IN_FINI_ARRAY= fi PREINIT_ARRAY=".preinit_array : { ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__preinit_array_start"));} KEEP (*(.preinit_array)) ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__preinit_array_end"));} }" INIT_ARRAY=".init_array : { ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__init_array_start"));} ${SORT_INIT_ARRAY} KEEP (*(.init_array ${CTORS_IN_INIT_ARRAY})) ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__init_array_end"));} }" FINI_ARRAY=".fini_array : { ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__fini_array_start"));} ${SORT_FINI_ARRAY} KEEP (*(.fini_array ${DTORS_IN_FINI_ARRAY})) ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__fini_array_end"));} }" CTOR=".ctors ${CONSTRUCTING-0} : { ${CONSTRUCTING+${CTOR_START}} /* gcc uses crtbegin.o to find the start of the constructors, so we make sure it is first. Because this is a wildcard, it doesn't matter if the user does not actually link against crtbegin.o; the linker won't look for a file to match a wildcard. The wildcard also means that it doesn't matter which directory crtbegin.o is in. */ KEEP (*crtbegin.o(.ctors)) KEEP (*crtbegin?.o(.ctors)) /* We don't want to include the .ctor section from the crtend.o file until after the sorted ctors. The .ctor section from the crtend file contains the end of ctors marker and it must be last */ KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o $OTHER_EXCLUDE_FILES) .ctors)) KEEP (*(SORT(.ctors.*))) KEEP (*(.ctors)) ${CONSTRUCTING+${CTOR_END}} }" DTOR=".dtors ${CONSTRUCTING-0} : { ${CONSTRUCTING+${DTOR_START}} KEEP (*crtbegin.o(.dtors)) KEEP (*crtbegin?.o(.dtors)) KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o $OTHER_EXCLUDE_FILES) .dtors)) KEEP (*(SORT(.dtors.*))) KEEP (*(.dtors)) ${CONSTRUCTING+${DTOR_END}} }" STACK=".stack ${RELOCATING-0}${RELOCATING+${STACK_ADDR}} : { ${RELOCATING+$(def_symbol "_stack");} *(.stack) ${RELOCATING+${STACK_SENTINEL}} }" test "${HAVE_NOINIT}" = "yes" && NOINIT=" /* This section contains data that is not initialized during load, or during the application's initialization sequence. */ .noinit ${RELOCATING-0} (NOLOAD) : ${RELOCATING+ALIGN(${ALIGNMENT})} { ${RELOCATING+PROVIDE (__noinit_start = .);} *(.noinit${RELOCATING+ .noinit.* .gnu.linkonce.n.*}) ${RELOCATING+. = ALIGN(${ALIGNMENT});} ${RELOCATING+PROVIDE (__noinit_end = .);} }" test "${HAVE_PERSISTENT}" = "yes" && PERSISTENT=" /* This section contains data that is initialized during load, but not during the application's initialization sequence. */ .persistent ${RELOCATING-0} : ${RELOCATING+ALIGN(${ALIGNMENT})} { ${RELOCATING+PROVIDE (__persistent_start = .);} *(.persistent${RELOCATING+ .persistent.* .gnu.linkonce.p.*}) ${RELOCATING+. = ALIGN(${ALIGNMENT});} ${RELOCATING+PROVIDE (__persistent_end = .);} }" TEXT_START_ADDR="SEGMENT_START(\"text-segment\", ${TEXT_START_ADDR})" SHLIB_TEXT_START_ADDR="SEGMENT_START(\"text-segment\", ${SHLIB_TEXT_START_ADDR:-0})" # Don't bother with separate code segment when there are data sections # between .plt and .text. if test -z "$TINY_READONLY_SECTION"; then case "$LD_FLAG" in *ro*textonly*) ALL_TEXT_BEFORE_RO=" " SEPARATE_TEXT=" " TEXT_SEGMENT_ALIGN=". = ALIGN(${MAXPAGESIZE});" ;; *textonly*) SEPARATE_TEXT=" " TEXT_SEGMENT_ALIGN=". = ALIGN(${MAXPAGESIZE});" ;; esac fi if [ -z "$SEPARATE_CODE" ]; then SIZEOF_HEADERS_CODE=" + SIZEOF_HEADERS" else SIZEOF_HEADERS_CODE= fi # If this is for an embedded system, don't add SIZEOF_HEADERS. if [ -z "$EMBEDDED" ]; then test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR}${SIZEOF_HEADERS_CODE}" else test -z "${TEXT_BASE_ADDRESS}" && TEXT_BASE_ADDRESS="${TEXT_START_ADDR}" fi # =========================================================================== # Functions for generating parts of the linker script # Helper function for putting comments into scripts. # Useful when trying to track down script composition problems. # Use by adding: # emit_comment "a message" # wherever necessary. emit_comment() { cat < ldscripts/dyntmp.$$ <> ldscripts/dyntmp.$$ <> ldscripts/dyntmp.$$ cat >> ldscripts/dyntmp.$$ <> ldscripts/dyntmp.$$ cat >> ldscripts/dyntmp.$$ <> ldscripts/dyntmp.$$ <