嵌入式（GPIO实验）（FS4412）

Makefile

TARGET = led-asm
CROSS_COMPILE = arm-none-linux-gnueabi-
CC = $(CROSS_COMPILE)gcc
LD = $(CROSS_COMPILE)ld
OBJCOPY = $(CROSS_COMPILE)objcopy

all:
	$(CC) -c $(TARGET).s -o $(TARGET).o
	$(LD) $(TARGET).o -Ttext 0x40008000 -o $(TARGET).elf
	$(OBJCOPY) -O binary -S $(TARGET).elf $(TARGET).bin

clean:
	rm $(TARGET).o $(TARGET).elf $(TARGET).bin

汇编

.text
_start:

MAIN:
	BL LED_CONFIG
LOOP:
	BL LED_ON
	BL DELAY
	BL LED_OFF
	BL DELAY
	B  LOOP

LED_CONFIG:
	LDR R2, =0x11000c40
	LDR R1, =0x10000000
	STR R1, [R2]
	MOV PC, LR

LED_ON:
	LDR R2, =0x11000c44
	LDR R1, =0x00000080
	STR R1, [R2]
	MOV PC, LR

LED_OFF:
	LDR R2, =0x11000c44
	LDR R1, =0x00000000
	STR R1, [R2]
	MOV PC, LR

DELAY:
	LDR R1, =100000000
L:
	SUB R1, R1, #1
	CMP R1, #0
	BNE L
	MOV PC, LR

STOP:
	B STOP

.end