刚刚开始学习嵌入式所以用汇编写了个流水等新人求帮助 多谢

#define	GPMCON	0x7F008820
#define	GPMDAT	0x7F008824

//_start default entry
.global _start
_start:
	//output
	ldr	r0,=0x7f008820
	ldr	r1,=0x1111
	str	r1,[r0]

	ldr	r0,=GPMDAT
loop:
	mov	r1,#0b1110
	str	r1,[r0]

	bl	delay

	mov	r1,#0b1101
	str	r1,[r0]

	bl	delay

	mov	r1,#0b1011
	str	r1,[r0]

	bl	delay

	mov	r1,#0b0111
	str	r1,[r0]

	bl	delay

	b	loop

delay:
	mov	r1,#0x100000
delay_loop:
	subs	r1,r1,#1
	bne	delay_loop
	mov	pc,lr