安防之家讯：文件strtest.c

1 #include <stdio.h>

2 extern void strcopy(char *d, const char *s);

3 int main()

4 { const char *srcstr = "First string - source";

5 char dststr[] = "Second string - destination";

6

7

8 printf("Before copying:\n");

9 printf(" '%s'\n '%s'\n",srcstr,dststr);

10 strcopy(dststr,srcstr);

11 printf("After copying:\n");

12 printf(" '%s'\n '%s'\n",srcstr,dststr);

13 return 0;

14 }

文件scopy.s

1 AREA SCopy, CODE, READONLY

2 EXPORT strcopy

3 strcopy

4 ; r0 points to destination string

5 ; r1 points to source string

6 LDRB r2, [r1],#1 ; load byte and update address

7 STRB r2, [r0],#1 ; store byte and update address;

8 CMP r2, #0 ; check for zero terminator

9 BNE strcopy ; keep going if not

10 MOV pc,lr ; Return

11 END安防之家专注于各种家居的安防,监控,防盗,安防监控,安防器材,安防设备的新闻资讯和O2O电商导购服务，敬请登陆安防之家：http://anfang.jc68.com/