説明のないとってもシンプルなサンプルプログラム集

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Linuxコマンド > ld リンクコマンド

1 ld [options] file...

sample.c(C言語ソース例)

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14  int a;
 int b=100;
 
 void c() __attribute__ ((section (".ABC_SECTION")));
 
 int main()
 {
 	c();
 }
 
 void c()
 {
 
 }

sample.ld(リンカスクリプト例)

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17  samplelabel = 0x1000;
 MEMORY
 {
 	rom (rx) : ORIGIN = 0, LENGTH = 128K
 	ram (!rx) : org = 0x10000, l = 1M
 	ram2 (!rx) : org = 0x40000, l = 4M
 }
 SECTIONS
 {
 	.text : { *(.text) } > rom
 	.data : {
 		*(.data)
 		*(.ABC_SECTION)
 	} > ram
 
 	.bss : { *(.bss) } > ram2
 }

~$ ls
sample.c
sample.ld
~$ gcc -c sample.c
~$ ls
sample.c
sample.ld
sample.o

リンカスクリプトを指定してリンクコマンド実行

~$ ld -T sample.ld sample.o

メモリMAP表示

~$ ld -T sample.ld sample.o -MAP

Allocating common symbols
Common symbol       size              file

a                   0x4               sample.o

Memory Configuration

Name             Origin             Length             Attributes
rom              0x0000000000000000 0x0000000000020000 xr
ram              0x0000000000010000 0x0000000000100000 !xr
ram2             0x0000000000040000 0x0000000000400000 !xr
*default*        0x0000000000000000 0xffffffffffffffff

Linker script and memory map

                0x0000000000001000                samplelabel = 0x1000

.text           0x0000000000000000        0xd
*(.text)
.text          0x0000000000000000        0xd sample.o
                0x0000000000000000                main

.iplt           0x0000000000000010        0x0
.iplt          0x0000000000000000        0x0 sample.o

.eh_frame       0x0000000000000010       0x58
.eh_frame      0x0000000000000010       0x58 sample.o

.rel.dyn        0x0000000000000068        0x0
.rel.iplt      0x0000000000000000        0x0 sample.o

.data           0x0000000000010000        0x9
*(.data)
.data          0x0000000000010000        0x4 sample.o
                0x0000000000010000                b
*(.ABC_SECTION)
.ABC_SECTION   0x0000000000010004        0x5 sample.o
                0x0000000000010004                c

.igot.plt       0x000000000001000c        0x0
.igot.plt      0x0000000000000000        0x0 sample.o

.bss            0x0000000000040000        0x4
*(.bss)
.bss           0x0000000000040000        0x0 sample.o
COMMON         0x0000000000040000        0x4 sample.o
                0x0000000000040000                a
LOAD sample.o
OUTPUT(a.out elf32-i386)

.comment        0x0000000000000000       0x1c
.comment       0x0000000000000000       0x1c sample.o
                                         0x1d (size before relaxing)

.note.GNU-stack
                0x0000000000000000        0x0
.note.GNU-stack
                0x0000000000000000        0x0 sample.o