[請益] 將C code某段函數轉換為彙編，使用gcc & gas
原始檔有兩個main1.c square.s
//main1.c
#include<stdio.h>
extern int square(int i);
int main(void)
{
int i;
for (i=0;i<10;i++)
{
printf("Square of %d is %d\n",i,square(i));
}
}
@square.s
.text
.global square
square:
MUL r1,r0,r0 @ r1 = r0 x r0
MOV r0,r1 @ r0 = r1
MOV pc,lr @ return r0
.end
編譯步驟與錯誤訊息如下
[leo@localhost main]$ ls
main1.c square.s
[leo@localhost main]$ gcc -c main1.c
[leo@localhost main]$ as -o square.o square.s
[leo@localhost main]$ ls
main1.c main1.o square.o square.s
[leo@localhost main]$ ld -o main1 main1.o square.o
ld: warning: cannot find entry symbol _start; defaulting to 00008074
main1.o: In function `main':
main1.c:(.text+0x34): undefined reference to `printf'
請問是哪裡的寫法不對?先謝謝各位
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