淺談ARM驅(qū)動開發(fā)-LED驅(qū)動（創(chuàng)建一個工程）

標(biāo)簽：

Linux

LED驱动-创建一个工程

1.汇编入口start.S

.global _start
.align 2
.text

_start:

bl  entry

.end

2.主文件app.c

#include "led.h"

void entry()
{
    led_init();

    int i = 30;

    while(i--)
    {
        led_on_all();
        delay(0xfffff);
        led_off_all();
        delay(0xfffff);     
    }
}

3.led头文件led.h

#ifndef __LED_H__
#define __LED_H__

#define GPM4CON (*(unsigned int *)0x110002e0)
#define GPM4DAT (*(unsigned int *)0x110002e4)

#endif

4.led驱动 led.c

#include "led.h"

void delay(int i)
{
    while(i--);
}

void led_init()
{
    GPM4CON = 0x1111;
}

void led_on_all()
{
    GPM4DAT = 0x0;
}

void led_off_all()
{
    GPM4DAT = 0xf;
}

void led_on(int i)
{
    GPM4DAT &= ~(0x1<<i);
}

void led_off(int i)
{
    GPM4DAT |= 0x1<<i;
}

5.makefile

# 1. arm-linux-gcc -c start.S -o start.o
# 2. arm-linux-gcc -c led.c -o led.o
# 3. arm-linux-gcc -c app.c -o app.o
# 4. arm-linux-ld -Ttext=0x40008000 start.o led.o app.o -o led
# 5. arm-linux-objcopy -O binary led led.bin

#######################################
TARGET=arm
BIN=$(TARGET).bin
OBJS=app.o led.o 
OBJS_S=start.o

#######################################
CROSS_COMPILE=arm-linux-
CC=$(CROSS_COMPILE)gcc
LD=$(CROSS_COMPILE)ld
OBJCOPY=$(CROSS_COMPILE)objcopy

#######################################
$(BIN):$(TARGET)
    $(OBJCOPY) -O binary $< $@
$(TARGET):$(OBJS_S) $(OBJS) 
    $(LD) -Ttext=0x40008000 $^ -o $@
%.o:%.S
    $(CC) -c $< -o $@
%.o:%.c
    $(CC) -c $< -o $@

#######################################
.PHONY:clean
clean:
    rm -rf *.o $(TARGET) $(BIN)

6.编译链接