Cortex A8 LED 点亮程序分析

1     Cortex A8 LED点亮程序分析

1.1     环境搭建准备工作

软件环境：            1.下载eclipse软件(绿色软件)

                             2.安装“yagarto-bu-2.22_gcc-4.7.1-c-c++_nl-1.20.0_gdb-7.4.1_eabi_20120616.exe”

                             3. tftpd32.exe

                                      下载路径：http://download.csdn.net/detail/wfq0624/5082504

硬件平台：           FS_S5PC100

 

搭建硬件环境：     1.PC UART-->开发板串口COM1(通过串口线)

                             2.电脑网卡-->开发板网卡(通过网线)

1.2     启动Eclipse软件，导入已有LED project

 

1.3     Makefile文件分析

红色字体必须根据实际安装路径和项目路径细微修改

# CORTEX-A8 PERI DRIVER CODE

# VERSION 1.0

# ATHUOR lapset ([e-mail])

# MODIFY DATE

#   2012.2.22 by lapset ,to change the format of Makefile

#NOTE :please fix the following info to adpat to your environment

CROSS_COMPILE=arm-none-eabi-

LDPATH="C:\Program Files\yagarto\lib\gcc\arm-none-eabi\4.7.1\include"

OUTPATH="G:\tftp"

NAME=led

COMMONPATH = "G:\ARM\example modify\led_FS_S5PC100\common\include"

#=============================================================================#

#DO NOT TO CHANG THE CODE AFTER THIS !!!

export CFLAGS LD CC STRIP OBJCOPY OBJDUMP COMMONPATH

CFLAGS +=   -g   -O0 -fno-strict-aliasing   -mabi=apcs-gnu -mfpu=vfpv3 -mfloat-abi=softfp  -fno-builtin -nostdinc   -isystem$(LDPATH) -I$(COMMONPATH)                                          

LD  = $(CROSS_COMPILE)ld

CC  = $(CROSS_COMPILE)gcc

STRIP  = $(CROSS_COMPILE)strip

OBJCOPY = $(CROSS_COMPILE)objcopy

OBJDUMP = $(CROSS_COMPILE)objdump

 

OBJS := start/start.o common/src/printf.o common/src/uart.o common/src/_udivsi3.o common/src/_umodsi3.o$(NAME).o

SUBDIRS := common/src/ start/

all:$(SUBDIRS)$(OBJS)

    $(LD) $(OBJS) -Tmap.lds -o$(NAME).elf

    $(OBJCOPY) -O binary $(NAME).elf$(NAME).bin

    $(OBJDUMP) -D$(NAME).elf >$(NAME).dis

    cp ./$(NAME).bin$(OUTPATH)

$(SUBDIRS):

    $(MAKE) -C $@

%.o: %.S

    $(CC)$(CFLAGS) -c -o $@ $<

%.o: %.c

    $(CC)$(CFLAGS) -c -o $@ $<

clean:

rm -rf $(OBJS) *.elf *.bin *.dis$(OUTPATH)/$(NAME).bin

1.4     Build project生成led.bin文件

1.    鼠标右击project name，选择“Build Project”

 

 

2.    成功后，会在该目录下【OUTPATH="G:\tftp"】生成led.bin文件，

如下所示,将tftpd32.exe和led.bin放在同一个目录下

1.5     配置ip地址

1.    让开发板上电，进入uboot

2.    输入pri 打印环境变量，使用setenv命令来修改参数，让ip和PC ip地址保持一致

3.    Ping ip地址，显示alive字样，表示网络连接OK

4.     打开PC上的tftpd32.exe软件，设置好对应的ip地址

 

              5.执行tftp下载led.bin到内存0x20008000地址处，然后运行该程序”go 20008000”