/*
* 调用atoi
*/
.arch armv6
.fpu softvfp
.data
msg:
.ascii "123"
fmt:
.asciz "atoi after = %d\n"
len = . - msg
.text
.global _start
_start:
ldr r0, =msg
bl atoi @ 调用atoi,结果存放在r0
mov r1, r0 @ 把r0存放到r1,r1会做为printf的第二个参数
ldr r0, =fmt @ printf("atoi after = %d\n")
bl printf @ printf("atoi after = %d\n", r1)
exit:
mov r0, #1
mov r7, #1
swi #0
编译:
/* arm-linux-gcc atoi.s -o atoi -nostdlib */