.OpenWrt驱动程序Makefile的分析概述 、驱动程序代码参考、以及测试程序代码参考
# # # include $(TOPDIR)/rules.mk //一般在 Makefile 的开头 include $(INCLUDE_DIR)/kernel.mk // 文件对于 软件包为内核时是不可缺少 PKG_NAME:=mydrv // 表示软件包名称，将在 menuconfig 和 ipkg 可以看到 PKG_RELEASE:=1 //表示软件包版本号 include $(INCLUDE_DIR)/package.mk //一般在软件包的基本信息完 成后再引入 define KernelPackage/mydrv //编译包定义，应用程序和内核驱动模块的定义不一样。应用程序软件包使用 Package，內核驱动模 块使用 KernelPackage。 SUBMENU:=Other modules //进行分类 TITLE:=mydrv //标题 FILES:=$(PKG_BUILD_DIR)/mydrv.ko //模块文件 KCONFIG:= endef define KernelPackage/mydrv/description This is a mydrv drivers //描述 endef MAKE_OPTS:= \ //编译之前指定工具和内核arch等 ARCH="$(LINUX_KARCH)" \ CROSS_COMPILE="$(TARGET_CROSS)" \ SUBDIRS="$(PKG_BUILD_DIR)" define Build/Prepare //编译前准备工作 mkdir -p $(PKG_BUILD_DIR) $(CP) ./src/* $(PKG_BUILD_DIR)/ endef define Build/Compile //进行编译 $(MAKE) -C "$(LINUX_DIR)" \ $(MAKE_OPTS) modules endef
$(eval $(call KernelPackage,mydrv))
以上为驱动程序Makefile代码，驱动程序有两个Makefile，驱动文件夹里有一个（上面）以及src里也有一个Makefile
进入src中Makefile
我们看一下Makefile的内容，非常简单： obj-m += mydrv.o
告诉内核添加的模块目标文件名称为mydrv.o
当前还包含有驱动程序
mydrv.c
/***************************** * * 驱动程序模板 * 版本：V1 * 使用方法(末行模式下)： * :%s/mydrv/"你的驱动名称"/g * *******************************/ #include <linux/mm.h> #include <linux/miscdevice.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/mman.h> #include <linux/random.h> #include <linux/init.h> #include <linux/raw.h> #include <linux/tty.h> #include <linux/capability.h> #include <linux/ptrace.h> #include <linux/device.h> #include <linux/highmem.h> #include <linux/crash_dump.h> #include <linux/backing-dev.h> #include <linux/bootmem.h> #include <linux/splice.h> #include <linux/pfn.h> #include <linux/export.h> #include <linux/io.h> #include <linux/aio.h> #include <linux/kernel.h> #include <linux/module.h> #include <asm/uaccess.h> #include <linux/ioctl.h> /**************** 基本定义 **********************/ //内核空间缓冲区定义 #if 0 #define KB_MAX_SIZE 20 #define kbuf[KB_MAX_SIZE]; #endif //加密函数参数内容： _IOW(IOW_CHAR , IOW_NUMn , IOW_TYPE) //加密函数用于mydrv_ioctl函数中 //使用举例：ioctl(fd , _IOW('L',0x80,long) , 0x1); //#define NUMn mydrv , if you need! #define IOW_CHAR 'L' #define IOW_TYPE long #define IOW_NUM1 0x80 //初始化函数必要资源定义 //用于初始化函数当中 //device number; dev_t dev_num; //struct dev struct cdev mydrv_cdev; //auto "mknode /dev/mydrv c dev_num minor_num" struct class *mydrv_class = NULL; struct device *mydrv_device = NULL; /**************** 结构体 file_operations 成员函数 *****************/ //open static int mydrv_open(struct inode *inode, struct file *file) { printk("mydrv drive open...\n"); return 0; } //close static int mydrv_close(struct inode *inode , struct file *file) { printk("mydrv drive close...\n"); return 0; } //read static ssize_t mydrv_read(struct file *file, char __user *buffer, size_t len, loff_t *pos) { int ret_v = 0; printk("mydrv drive read...\n"); return ret_v; } //write static ssize_t mydrv_write( struct file *file , const char __user *buffer, size_t len , loff_t *offset ) { int ret_v = 0; printk("mydrv drive write...\n"); return ret_v; } //unlocked_ioctl static int mydrv_ioctl (struct file *filp , unsigned int cmd , unsigned long arg) { int ret_v = 0; printk("mydrv drive ioctl...\n"); switch(cmd) { //常规： //cmd值自行进行修改 case 0x1: { if(arg == 0x1) //第二条件； { } } break; //带密码保护： //请在"基本定义"进行必要的定义 case _IOW(IOW_CHAR,IOW_NUM1,IOW_TYPE): { if(arg == 0x1) //第二条件 { } } break; default: break; } return ret_v; } /***************** 结构体： file_operations ************************/ //struct static const struct file_operations mydrv_fops = { .owner = THIS_MODULE, .open = mydrv_open, .release = mydrv_close, .read = mydrv_read, .write = mydrv_write, .unlocked_ioctl = mydrv_ioctl, }; /************* functions: init , exit*******************/ //条件值变量，用于指示资源是否正常使用 unsigned char init_flag = 0; unsigned char add_code_flag = 0; //init static __init int mydrv_init(void) { int ret_v = 0; printk("mydrv drive init...\n"); //函数alloc_chrdev_region主要参数说明： //参数2： 次设备号 //参数3： 创建多少个设备 if( ( ret_v = alloc_chrdev_region(&dev_num,0,1,"mydrv") ) < 0 ) { goto dev_reg_error; } init_flag = 1; //标示设备创建成功； printk("The drive info of mydrv:\nmajor: %d\nminor: %d\n", MAJOR(dev_num),MINOR(dev_num)); cdev_init(&mydrv_cdev,&mydrv_fops); if( (ret_v = cdev_add(&mydrv_cdev,dev_num,1)) != 0 ) { goto cdev_add_error; } mydrv_class = class_create(THIS_MODULE,"mydrv"); if( IS_ERR(mydrv_class) ) { goto class_c_error; } mydrv_device = device_create(mydrv_class,NULL,dev_num,NULL,"mydrv"); if( IS_ERR(mydrv_device) ) { goto device_c_error; } printk("auto mknod success!\n"); //------------ 请在此添加您的初始化程序 --------------// //如果需要做错误处理，请：goto mydrv_error; add_code_flag = 1; //---------------------- END ---------------------------// goto init_success; dev_reg_error: printk("alloc_chrdev_region failed\n"); return ret_v; cdev_add_error: printk("cdev_add failed\n"); unregister_chrdev_region(dev_num, 1); init_flag = 0; return ret_v; class_c_error: printk("class_create failed\n"); cdev_del(&mydrv_cdev); unregister_chrdev_region(dev_num, 1); init_flag = 0; return PTR_ERR(mydrv_class); device_c_error: printk("device_create failed\n"); cdev_del(&mydrv_cdev); unregister_chrdev_region(dev_num, 1); class_destroy(mydrv_class); init_flag = 0; return PTR_ERR(mydrv_device); //------------------ 请在此添加您的错误处理内容 ----------------// mydrv_error: add_code_flag = 0; return -1; //-------------------- END -------------------// init_success: printk("mydrv init success!\n"); return 0; } //exit static __exit void mydrv_exit(void) { printk("mydrv drive exit...\n"); if(add_code_flag == 1) { //---------- 请在这里释放您的程序占有的资源 ---------// printk("free your resources...\n"); printk("free finish\n"); //---------------------- END -------------------// } if(init_flag == 1) { //释放初始化使用到的资源; cdev_del(&mydrv_cdev); unregister_chrdev_region(dev_num, 1); device_unregister(mydrv_device); class_destroy(mydrv_class); } } /**************** module operations**********************/ //module loading module_init(mydrv_init); module_exit(mydrv_exit); //some infomation MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("from Jafy"); MODULE_DESCRIPTION("mydrv drive"); /********************* The End ***************************/
测试程序mydir_app
Makefile
##Copyright (C) 2012 OpenWrt.org # # This is free software, licensed under the GNU General Public License v2. # See /LICENSE for more information. # include $(TOPDIR)/rules.mk PKG_NAME:=mydrv_app PKG_RELEASE:=1 PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME) include $(INCLUDE_DIR)/package.mk define Package/mydrv_app SECTION:=utils CATEGORY:=Utilities TITLE:=Frame buffer device testing tool DEPENDS:=+libncurses endef define Build/Prepare mkdir -p $(PKG_BUILD_DIR) $(CP) ./src/* $(PKG_BUILD_DIR)/ endef define Build/Configure endef TARGET_LDFLAGS := define Build/Compile $(MAKE) -C $(PKG_BUILD_DIR) \ CC="$(TARGET_CC)" \ CFLAGS="$(TARGET_CFLAGS) -Wall" \ LDFLAGS="$(TARGET_LDFLAGS)" endef define Package/mydrv_app/install $(INSTALL_DIR) $(1)/usr/sbin $(INSTALL_BIN) $(PKG_BUILD_DIR)/mydrv_app $(1)/usr/sbin/ endef $(eval $(call BuildPackage,mydrv_app))
进入src文件夹
Makefile
ll: mydrv_app OBJS = mydrv_app.o CC = gcc CCFLAGS = -Wall -c -o %.o: %.c $(CC) $(CCFLAGS) $@ $< $(LDFLAGS) fbtest: $(OBJS) $(CC) -o $@ $(OBJS) $(LDFLAGS) clean: rm -f rbcfg *.o
测试程序代码
#include <stdio.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/ioctl.h> int main(int argc , char** argv) { int fd; int num = 1; //打开驱动模块 fd = open("/dev/mydrv" , O_RDWR|O_NONBLOCK); if(fd < 0) { printf("can't open /dev/mydrv\n"); return -1; } //函数测试 write(fd,&num,1); read(fd,&num,1); ioctl(fd,1,1); close(fd); return 0; }
