GNU ld (Sourcery G++ Lite 2008q3-41) 2.18.50.20080215
Supported emulations:
armelf_linux_eabi
armelfb_linux_eabi
using internal linker script:
==================================================
/* Script for -z combreloc: combine and sort reloc sections */
OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm",
"elf32-littlearm")
OUTPUT_ARCH(arm)
ENTRY(_start)
SEARCH_DIR("=/usr/local/lib"); SEARCH_DIR("=/lib"); SEARCH_DIR("=/usr/lib");
SECTIONS
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*(.rel.tbss .rel.tbss.* .rel.gnu.linkonce.tb.*)
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*(.rel.bss .rel.bss.* .rel.gnu.linkonce.b.*)
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KEEP (*(.init))
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*(.text .stub .text.* .gnu.linkonce.t.*)
/* .gnu.warning sections are handled specially by elf32.em. */
*(.gnu.warning)
*(.glue_7t) *(.glue_7) *(.vfp11_veneer) *(.v4_bx)
} =0
.fini :
{
KEEP (*(.fini))
} =0
PROVIDE (__etext = .);
PROVIDE (_etext = .);
PROVIDE (etext = .);
.rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) }
.rodata1 : { *(.rodata1) }
.ARM.extab : { *(.ARM.extab* .gnu.linkonce.armextab.*) }
__exidx_start = .;
.ARM.exidx : { *(.ARM.exidx* .gnu.linkonce.armexidx.*) }
__exidx_end = .;
.eh_frame_hdr : { *(.eh_frame_hdr) }
.eh_frame : ONLY_IF_RO { KEEP (*(.eh_frame)) }
.gcc_except_table : ONLY_IF_RO { *(.gcc_except_table .gcc_except_table.*) }
/* Adjust the address for the data segment. We want to adjust up to
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. = ALIGN (CONSTANT (MAXPAGESIZE)) - ((CONSTANT (MAXPAGESIZE) - .) & (CONSTANT (MAXPAGESIZE) - 1)); . = DATA_SEGMENT_ALIGN (CONSTANT (MAXPAGESIZE), CONSTANT (COMMONPAGESIZE));
/* Exception handling */
.eh_frame : ONLY_IF_RW { KEEP (*(.eh_frame)) }
.gcc_except_table : ONLY_IF_RW { *(.gcc_except_table .gcc_except_table.*) }
/* Thread Local Storage sections */
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.tbss : { *(.tbss .tbss.* .gnu.linkonce.tb.*) *(.tcommon) }
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{
PROVIDE_HIDDEN (__preinit_array_start = .);
KEEP (*(.preinit_array))
PROVIDE_HIDDEN (__preinit_array_end = .);
}
.init_array :
{
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array))
PROVIDE_HIDDEN (__init_array_end = .);
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KEEP (*(SORT(.fini_array.*)))
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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
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The .ctor section from the crtend file contains the
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KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .ctors))
KEEP (*(SORT(.ctors.*)))
KEEP (*(.ctors))
}
.dtors :
{
KEEP (*crtbegin.o(.dtors))
KEEP (*crtbegin?.o(.dtors))
KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .dtors))
KEEP (*(SORT(.dtors.*)))
KEEP (*(.dtors))
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*(.data .data.* .gnu.linkonce.d.*)
SORT(CONSTRUCTORS)
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*(.dynbss)
*(.bss .bss.* .gnu.linkonce.b.*)
*(COMMON)
/* Align here to ensure that the .bss section occupies space up to
_end. Align after .bss to ensure correct alignment even if the
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FIXME: Why do we need it? When there is no .bss section, we don't
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/* DWARF debug sections.
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/* DWARF 2 */
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/* DWARF 3 */
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/DISCARD/ : { *(.note.GNU-stack) *(.gnu_debuglink) }
}
==================================================
/*
* linux/arch/arm/boot/compressed/vmlinux.lds.in
*
* Copyright (C) 2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
OUTPUT_ARCH(arm)
ENTRY(_start)
SECTIONS
{
/DISCARD/ : {
*(.ARM.exidx*)
*(.ARM.extab*)
/*
* Discard any r/w data - this produces a link error if we have any,
* which is required for PIC decompression. Local data generates
* GOTOFF relocations, which prevents it being relocated independently
* of the text/got segments.
*/
*(.data)
}
. = 0; /* 주소를 0x0 으로 지정한다. */
_text = .; /* 이 곳에 심볼 _text 를 정의한다. 코드 영역의 시작 지정 */
.text : { /* 섹션이름 .text 영역 정의 */
_start = .; /* 이 곳에 심볼 _start 를 정의한다. */
*(.start) /* .start 섹션으로 정의된 코드 부터 차례로 배열 된다. */
*(.text)
*(.text.*)
*(.fixup)
*(.gnu.warning)
*(.glue_7t)
*(.glue_7)
}
.rodata : { /* 섹션이름 .rodata 영역 정의 */
*(.rodata)
*(.rodata.*)
}
.piggydata : { /* 섹션이름 .piggydata 영역 정의 */
*(.piggydata)
}
. = ALIGN(4);
_etext = .; /* 이 곳에 심볼 _etext 를 정의한다. 코드 영역의 끝 지정 */
.got.plt : { *(.got.plt) }
_got_start = .;
.got : { *(.got) } /* got 영역 */
_got_end = .;
_edata = .;
. = ALIGN(8);
__bss_start = .;
.bss : { *(.bss) } /* bss 영역 */
_end = .;
. = ALIGN(8); /* the stack must be 64-bit aligned */
.stack : { *(.stack) }
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
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.stab.indexstr 0 : { *(.stab.indexstr) }
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스크립터에 사용 된 명령을 살펴 보자.
OUT_ARCH(arm) : 출력 아키텍쳐를 지정한다.
ENTRY(_start) : 프로그램에서 처음 실행되는 진입점이다. 심볼명을 지정한다.
SECTION { } : 링커가 어떻게 입력 섹션을 출력 섹션으로 대응하고, 출력 섹션을 메모리에 배치하는지를 지정한다.
'/DISCARD/' : 특별한 출력 세션 이름으로 입력 섹션을 버리는 용도로 사용한다. 이 섹션으로 지정된 입력은 실제로 출력으로 배치되지 않는다.
objdump -h 명령으로 어떠한 섹션이 있는지 살펴 보자.
$ arm-linux-objdump -h arch/arm/boot/compressed/vmlinux
arch/arm/boot/compressed/vmlinux: file format elf32-littlearm
Sections:
Idx Name Size VMA LMA File off Algn
0 .text 00003b50 00000000 00000000 00008000 2**5
CONTENTS, ALLOC, LOAD, READONLY, CODE
1 .rodata 00000c94 00003b50 00003b50 0000bb50 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
2 .piggydata 0012bf8c 000047e4 000047e4 0000c7e4 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
3 .got.plt 0000000c 00130770 00130770 00138770 2**2
CONTENTS, ALLOC, LOAD, DATA
4 .got 0000002c 0013077c 0013077c 0013877c 2**2
CONTENTS, ALLOC, LOAD, DATA
5 .bss 00000020 001307a8 001307a8 001387a8 2**2
ALLOC
6 .stack 00001000 001307c8 001307c8 001387a8 2**0
ALLOC
7 .comment 00000054 00000000 00000000 001387a8 2**0
CONTENTS, READONLY
8 .ARM.attributes 00000029 00000000 00000000 001387fc 2**0
CONTENTS, READONLY
9 .debug_line 0000107d 00000000 00000000 00138825 2**0
CONTENTS, READONLY, DEBUGGING
10 .debug_info 000018bc 00000000 00000000 001398a2 2**0
CONTENTS, READONLY, DEBUGGING
11 .debug_abbrev 00000633 00000000 00000000 0013b15e 2**0
CONTENTS, READONLY, DEBUGGING
12 .debug_aranges 00000088 00000000 00000000 0013b798 2**3
CONTENTS, READONLY, DEBUGGING
13 .debug_ranges 00000548 00000000 00000000 0013b820 2**3
CONTENTS, READONLY, DEBUGGING
14 .debug_frame 000001f8 00000000 00000000 0013bd68 2**2
CONTENTS, READONLY, DEBUGGING
15 .debug_loc 00002791 00000000 00000000 0013bf60 2**0
CONTENTS, READONLY, DEBUGGING
16 .debug_pubnames 000001a4 00000000 00000000 0013e6f1 2**0
CONTENTS, READONLY, DEBUGGING
17 .debug_str 00000688 00000000 00000000 0013e895 2**0
CONTENTS, READONLY, DEBUGGING
출력되는 섹션의 배치를 간략하게 그림으로 표현했다.
코드상에서 정의된 심볼의 값
.word 0x016f2818 | 24: 016f2818 .word 0x016f2818
.word start | 28: 00000000 .word 0x00000000
.word _edata | 2c: 001307a8 .word 0x001307a8
.type LC0, #object |0000017c <LC0>:
LC0: .word LC0 | 17c: 0000017c .word 0x0000017c
.word __bss_start | 180: 001307a8 .word 0x001307a8
.word _end | 184: 001307c8 .word 0x001307c8
.word _edata | 188: 001307a8 .word 0x001307a8
.word input_data_end - 4 | 18c: 0013076c .word 0x0013076c
.word _got_start | 190: 0013077c .word 0x0013077c
.word _got_end | 194: 001307a8 .word 0x001307a8
.word .L_user_stack_end | 198: 001317c8 .word 0x001317c8
.size LC0, . - LC0 | 19c: e1a00000 .word 0xe1a00000
