一、编写源码
1:文件·1_led.s：

.text
.global _start
_start:
ldr r0,=0x56000010
mov r1,#0x00015400
str r1,[r0]
ldr r0,=0x56000014
loop: mov r1,#0x00000000
str r1,[r0]
bl delay
mov r1,#0x00000ff0
str r1,[r0]
bl delay
b loop

delay:
mov r4,#100
del1: mov r5,#1000
del2: sub r5,r5,#1
nop
cmp r5,#1
bne del2
sub r4,r4,#1
nop
cmp r4,#1
bne del1
mov pc,lr

2:文件Makefile:

1_led.bin:1_led.s
arm-linux-gcc -g -c -o 1_led.o 1_led.s
arm-linux-ld -Ttext 0x00000000 -g 1_led.o -o 1_led_elf
arm-linux-objcopy -O binary -S 1_led_elf 1_led.bin
arm-linux-objdump -D 1_led_elf > 1_led.dis
clean:
rm -f 1_led.bin *.o 1_led_elf 1_led.dis

把1_led.bin下载到dram中运行