$ ls add.s libcal.a main.c Makefile prt.s sub.s $
# add.s
.type add, @function
.globl add
add: # add two integer
pushl %ebp
movl %esp, %ebp
movl 8(%ebp), %eax
addl 12(%ebp), %eax
movl %ebp, %esp
popl %ebp
ret
.type add_inc, @function
.globl add_inc
add_inc: # add 1 to int parameter
pushl %ebp
movl %esp, %ebp
movl 8(%ebp), %eax
inc %eax
movl %ebp, %esp
popl %ebp
ret
# sub.s
.type sub, @function
.globl sub
sub: # sub two integer
pushl %ebp
movl %esp, %ebp
movl 8(%ebp), %eax
subl 12(%ebp), %eax
movl %ebp, %esp
popl %ebp
ret
.type sub_dec, @function
.globl sub_dec
sub_dec: # sub 1 to int parameter
pushl %ebp
movl %esp, %ebp
movl 8(%ebp), %eax
dec %eax
movl %ebp, %esp
popl %ebp
ret
.type print_hello, @function
.section .data
msg:
.ascii "hello world!\n"
len=.-msg
.section .text
.global print_hello
print_hello:
movl $len, %edx
movl $msg, %ecx
movl $1, %ebx
movl $4, %eax
int $0x80
movl $0, %ebx
movl $1, %eax
int $0x80# main.c
#include <stdio.h>
int add(int, int);
int add_inc(int);
int sub(int, int);
int sub_dec(int);
int print_hello(void);
int main(int argc, const char *argv[])
{
int ret;
ret = add(1989, 711);
printf("The add() return is %d.\n", ret);
ret = add_inc(1989);
printf("The add_inc() return is %d.\n", ret);
ret = sub(1989, 711);
printf("The sub() return is %d.\n", ret);
ret = sub_dec(1989);
printf("The sub_dec() return is %d.\n", ret);
print_hello();
return 0;
}# Makefile for linux as CFLAGS= -Wall -g ASFLAGS= -gstabs SRC_BIN=target_bin SRC_LIB=libcal.a SRC_C=$(wildcard *.c) SRC_S=$(wildcard *.s) SRC_COBJ=$(SRC_C:.c=.o) SRC_SOBJ=$(SRC_S:.s=.o) SRC_OBJ=$(SRC_COBJ) $(SRC_SOBJ) all: $(SRC_BIN) $(SRC_BIN): $(SRC_COBJ) $(SRC_LIB) $(CC) -o $@ $(SRC_COBJ) -L./ -lcal $(SRC_LIB) : $(SRC_SOBJ) ar rcs $@ $^ clean: $(RM) $(SRC_OBJ) $(SRC_BIN) *~ .PHONY: all clean
$ ar t libcal.a add.o prt.o sub.o
$ nm -s libcal.a Archive index: add in add.o add_inc in add.o print_hello in prt.o sub in sub.o sub_dec in sub.o add.o: 00000000 T add 0000000d T add_inc prt.o: 0000000d a len 00000000 d msg 00000000 T print_hello sub.o: 00000000 T sub 0000000d T sub_dec
$ cat Makefile.static # Makefile for linux as CFLAGS= -Wall -g ASFLAGS= -gstabs SRC_BIN=target_bin SRC_LIB=libcal.a SRC_C=$(wildcard *.c) SRC_S=$(wildcard *.s) SRC_COBJ=$(SRC_C:.c=.o) SRC_SOBJ=$(SRC_S:.s=.o) SRC_OBJ=$(SRC_COBJ) $(SRC_SOBJ) all: $(SRC_BIN) $(SRC_BIN): $(SRC_COBJ) $(SRC_LIB) $(CC) -o $@ $(SRC_COBJ) -L./ -lcal $(SRC_LIB) : $(SRC_SOBJ) ar rcs $@ $^ clean: $(RM) $(SRC_OBJ) $(SRC_BIN) *~ .PHONY: all clean
$ make -f Makefile.share cc -Wall -g -c -o main.o main.c as -gstabs -o add.o add.s as -gstabs -o prt.o prt.s as -gstabs -o sub.o sub.s gcc -shared -o libcal.so add.o prt.o sub.o cc -o target_bin main.o -L./ -lcal
$ ldd target_bin linux-gate.so.1 => (0x00dac000) libcal.so => not found libc.so.6 => /lib/libc.so.6 (0x00a42000) /lib/ld-linux.so.2 (0x00a1c000)
$ ./target_bin ./target_bin: error while loading shared libraries: libcal.so: cannot open shared object file: No such file or directory
$ cat /etc/ld.so.conf include ld.so.conf.d/*.conf
$ ls /etc/ld.so.conf.d/ atlas-i386.conf kernel-2.6.32-358.el6.i686.conf mysql-i386.conf qt-i386.conf xulrunner-32.conf上面每个配置文件就是对于每个应用查找其对应共享库的路径。
# ./target_bin The add() return is 2700. The add_inc() return is 1990. The sub() return is 1278. hello world!本系列linux汇编学习到此为止，在这二十节的内容中，可能没有讲解到汇编的所有方面，但还是把汇编语言的比较常用的基本知识通过一些很简单很基础的示例展示了出来，我希望读者在看完本系列文章之后有所有收获，也希望读者在阅读文章是能指出其中的错误和不足。
原文地址：http://blog.csdn.net/shallnet/article/details/45651491
