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elf2flt.ld.in
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elf2flt.ld.in
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/* This linker script is used to produce a tighter ELF program in preparation
for conversion to the flat format. It takes inputs (e.g. ELF objects) and
arranges their sections in the order the runtime expects. See the GNU linker
script documentation for more details on the file format.
https://sourceware.org/binutils/docs/ld/Scripts.html
It is dynamically processed by ld-elf2flt before being passed to GNU ld which
links the final ELF image (which is then passed to elf2flt to create the flat
program).
The "elf2flt.ld.in" file has @FOO@ symbols replaced when the elf2flt project
itself is built. These should ideally be kept to a minimum to make it easier
to read & understand this script.
The lines below that start with "FOO:" tags are custom ld-elf2flt logic and
*not* part of the linker script language. When ld-elf2flt runs, based on its
flags, it will either delete the entire line or the tag itself.
The tags currently defined are as follows (in no particular order).
R_RODAT:
W_RODAT:
By default, the read-only data (.rodata) input sections are placed into the
writable output data segment (via the output .data section) and before any
other input data sections. The -move-rodata option moves the .rodata input
to the read-only output text segment (via the output .text section).
Thus, R_RODAT lines are kept by default, while W_RODAT lines are removed.
TOR:
The --enable-emit-ctor-dtor configure setting.
By default, all TOR lines are removed.
SINGLE_LINK:
The --disable-emit-relocs configure setting.
By default, all SINGLE_LINK are kept.
*/
ENTRY (@SYMBOL_PREFIX@_start)
MEMORY {
flatmem : ORIGIN = 0x0, LENGTH = 0xfffffff
}
PHDRS {
text PT_LOAD ;
data PT_LOAD ;
}
SECTIONS {
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. = . + 4;
. = ALIGN(0x4) ;
@SYMBOL_PREFIX@_stext = . ;
*(.literal .text)
*(.literal.* .text.*)
*(.gnu.warning)
*(.stub)
*(.gnu.linkonce.literal.*)
*(.gnu.linkonce.t*)
*(.glue_7t)
*(.glue_7)
*(.jcr)
*(.init.literal)
KEEP (*(.init))
*(.fini.literal)
KEEP (*(.fini))
W_RODAT: *(.rodata)
W_RODAT: *(.rodata1)
W_RODAT: *(.rodata.*)
W_RODAT: *(.gnu.linkonce.r*)
/* .ARM.extab name sections containing exception unwinding information */
*(.ARM.extab* .gnu.linkonce.armextab.*)
/* .ARM.exidx name sections containing index entries for section unwinding */
@SYMBOL_PREFIX@__exidx_start = .;
*(.ARM.exidx* .gnu.linkonce.armexidx.*)
@SYMBOL_PREFIX@__exidx_end = .;
/* This is special code area at the end of the normal
text section. It contains a small lookup table at
the start followed by the code pointed to by entries
in the lookup table. */
. = ALIGN (4) ;
PROVIDE(@SYMBOL_PREFIX@__ctbp = .);
*(.call_table_data)
*(.call_table_text)
@SYMBOL_PREFIX@_etext = . ;
} > flatmem :text
.data ALIGN(0x20): {
@SYMBOL_PREFIX@_sdata = . ;
@SYMBOL_PREFIX@__data_start = . ;
@SYMBOL_PREFIX@data_start = . ;
*(.got.plt)
*(.got)
FILL(0) ;
. = ALIGN(0x20) ;
LONG(-1)
. = ALIGN(0x20) ;
RISCV_GP: __global_pointer$ = . + 0x800 ;
R_RODAT: *(.rodata)
R_RODAT: *(.rodata1)
R_RODAT: *(.rodata.*)
R_RODAT: *(.gnu.linkonce.r*)
*(.data)
*(.data1)
*(.data.*)
*(.gnu.linkonce.d*)
/* Microblaze has .sdata and .sbss (small bss). They must
be contiguous, so please don't move any of this. JW */
@SYMBOL_PREFIX@_ssrw = . ;
*(.sdata)
*(.sdata.*)
*(.sbss) /* Don't move this! */
*(.gnu.linkonce.sb*)
@SYMBOL_PREFIX@_essrw = . ;
@SYMBOL_PREFIX@_ssrw_size = @SYMBOL_PREFIX@_essrw - @SYMBOL_PREFIX@_ssrw;
PROVIDE(@SYMBOL_PREFIX@_SDA_BASE_ = @SYMBOL_PREFIX@_ssrw + (@SYMBOL_PREFIX@_ssrw_size / 2));
*(.gnu.linkonce.s.*)
*(__libc_atexit)
*(__libc_subinit)
*(__libc_subfreeres)
/* microblaze-specific read-only small data area
and associated locating symbols */
@SYMBOL_PREFIX@_ssro = . ;
*(.sdata2)
@SYMBOL_PREFIX@_essro = . ;
@SYMBOL_PREFIX@_ssro_size = @SYMBOL_PREFIX@_essro - @SYMBOL_PREFIX@_ssro;
PROVIDE(@SYMBOL_PREFIX@_SDA2_BASE_ = @SYMBOL_PREFIX@_ssro + (@SYMBOL_PREFIX@_ssro_size / 2));
. = ALIGN(8) ;
TOR: @SYMBOL_PREFIX@__CTOR_LIST__ = .;
TOR: LONG((@SYMBOL_PREFIX@__CTOR_END__ - @SYMBOL_PREFIX@__CTOR_LIST__) / 4 - 2)
SINGLE_LINK: /* gcc uses crtbegin.o to find the start of
SINGLE_LINK: the constructors, so we make sure it is
SINGLE_LINK: first. Because this is a wildcard, it
SINGLE_LINK: doesn't matter if the user does not
SINGLE_LINK: actually link against crtbegin.o; the
SINGLE_LINK: linker won't look for a file to match a
SINGLE_LINK: wildcard. The wildcard also means that it
SINGLE_LINK: doesn't matter which directory crtbegin.o
SINGLE_LINK: is in. */
SINGLE_LINK: KEEP (*crtbegin*.o(.ctors))
SINGLE_LINK: /* We don't want to include the .ctor section from
SINGLE_LINK: from the crtend.o file until after the sorted ctors.
SINGLE_LINK: The .ctor section from the crtend file contains the
SINGLE_LINK: end of ctors marker and it must be last */
SINGLE_LINK: KEEP (*(EXCLUDE_FILE (*crtend*.o ) .ctors))
SINGLE_LINK: KEEP (*(SORT(.ctors.*)))
KEEP (*(.ctors))
TOR: LONG(0)
TOR: @SYMBOL_PREFIX@__CTOR_END__ = .;
TOR: @SYMBOL_PREFIX@__DTOR_LIST__ = .;
TOR: LONG((@SYMBOL_PREFIX@__DTOR_END__ - @SYMBOL_PREFIX@__DTOR_LIST__) / 4 - 2)
SINGLE_LINK: KEEP (*crtbegin*.o(.dtors))
SINGLE_LINK: KEEP (*(EXCLUDE_FILE (*crtend*.o ) .dtors))
SINGLE_LINK: KEEP (*(SORT(.dtors.*)))
KEEP (*(.dtors))
TOR: LONG(0)
TOR: @SYMBOL_PREFIX@__DTOR_END__ = .;
PROVIDE (@SYMBOL_PREFIX@__preinit_array_start = .);
KEEP (*(.preinit_array))
PROVIDE (@SYMBOL_PREFIX@__preinit_array_end = .);
PROVIDE (@SYMBOL_PREFIX@__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array))
PROVIDE (@SYMBOL_PREFIX@__init_array_end = .);
PROVIDE (@SYMBOL_PREFIX@__fini_array_start = .);
KEEP (*(.fini_array))
KEEP (*(SORT(.fini_array.*)))
PROVIDE (@SYMBOL_PREFIX@__fini_array_end = .);
} > flatmem :data
.note.ABI-tag : { *(.note.ABI-tag) } > flatmem
.eh_frame_hdr : { *(.eh_frame_hdr) } > flatmem
.eh_frame : { KEEP(*(.eh_frame)) } > flatmem
.gcc_except_table : {
KEEP(*(.gcc_except_table))
KEEP(*(.gcc_except_table.*))
} >flatmem
. = ALIGN(0x10) ;
@SYMBOL_PREFIX@_edata = . ;
.bss : {
. = ALIGN(0x4) ;
@SYMBOL_PREFIX@_sbss = ALIGN(0x4) ;
@SYMBOL_PREFIX@__bss_start = . ;
*(.dynsbss)
*(.sbss)
*(.sbss.*)
*(.scommon)
*(.dynbss)
*(.bss)
*(.bss.*)
*(.bss*)
*(.gnu.linkonce.b*)
*(COMMON)
. = ALIGN(0x10) ;
@SYMBOL_PREFIX@_ebss = . ;
@SYMBOL_PREFIX@_end = . ;
@SYMBOL_PREFIX@end = . ;
} > flatmem
.stack : {
. = ALIGN(0x4);
@SYMBOL_PREFIX@_stack_start = .;
} > flatmem
.junk 0 : { *(.rel*) *(.rela*) }
/DISCARD/ : { *(.note.GNU-stack) }
/* Stabs debugging sections. */
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
.stab.exclstr 0 : { *(.stab.exclstr) }
.stab.index 0 : { *(.stab.index) }
.stab.indexstr 0 : { *(.stab.indexstr) }
.comment 0 : { *(.comment) }
/* DWARF debug sections.
Symbols in the DWARF debugging sections are relative to the beginning
of the section so we begin them at 0. */
/* DWARF 1 */
.debug 0 : { *(.debug) }
.line 0 : { *(.line) }
/* GNU DWARF 1 extensions */
.debug_srcinfo 0 : { *(.debug_srcinfo) }
.debug_sfnames 0 : { *(.debug_sfnames) }
/* DWARF 1.1 and DWARF 2 */
.debug_aranges 0 : { *(.debug_aranges) }
.debug_pubnames 0 : { *(.debug_pubnames) }
/* DWARF 2 */
.debug_info 0 : { *(.debug_info .gnu.linkonce.wi.*) }
.debug_abbrev 0 : { *(.debug_abbrev) }
.debug_line 0 : { *(.debug_line) }
.debug_frame 0 : { *(.debug_frame) }
.debug_str 0 : { *(.debug_str) }
.debug_loc 0 : { *(.debug_loc) }
.debug_macinfo 0 : { *(.debug_macinfo) }
/* SGI/MIPS DWARF 2 extensions */
.debug_weaknames 0 : { *(.debug_weaknames) }
.debug_funcnames 0 : { *(.debug_funcnames) }
.debug_typenames 0 : { *(.debug_typenames) }
.debug_varnames 0 : { *(.debug_varnames) }
}