我的第乙個字元裝置驅動程式 First drv

2021-06-17 21:19:32 字數 2144 閱讀 4898

/*驅動程式*/

#include#include#include#include#include#include#include#include#include#include module_license("gpl");

static struct class *firstdrv_class;

static struct device *firstdrv_class_dev;

static int first_drv_open(struct inode *inode,struct file *file)

static ssize_t first_drv_write(struct file *file,const char __user *buf,size_t count,loff_t * ppos)

/*頂乙個file_operation結構*/

static struct file_operations first_drv_fops = ;

int major;

/*驅動入口函式*/

int first_drv_init(void)

firstdrv_class_dev=device_create(firstdrv_class,null,mkdev(major,0),null,"xyz");

if(unlikely(is_err(firstdrv_class_dev)))

return ptr_err(firstdrv_class_dev);

return 0;

}void first_drv_exit(void)

/*宣告入口函式*/

module_init(first_drv_init);

module_exit(first_drv_exit);

#mkefile檔案

kern_dir=/work/system/linux-2.6.32.2

all:

make -c $(kern_dir) m=`pwd` modules

clean:

make -c $(kern_dir) m=`pwd` modules clean

obj-m +=first_drv.o

/*測試***/

#include#include#include#includeint main(int argc,char **argv)

期間碰到的問題:

1、fatal: modpost: gpl-incompatible module first_drv.ko uses gpl-only symbol 'device_create'

解決方法:在標頭檔案之後加上,加在其他位置無效

module_license("gpl");

2、 implicit declaration of function 'class_device_create'

解決方法:本次試驗所用核心為linux-2.6.32.2,已不支援此函式,改為device_create 標頭檔案為:device.h

3、./test: line 2: : not found

./test: line 2: 4: not found

./test: line 2:  not found

./test: line 2: elf!$: not found

./test: line 1: syntax error: word unexpected (expecting ")")

解決方法:用錯編譯鏈,一定要用arm-linux-gcc   而不是gcc    即:arm-linux-gcc -o test test.c

現翻譯下**:

首先,實現裝置的open.write,read等程式,接著為這些方法找宿主,實現乙個file_operation結構,此結構相當於乙個一級容器,裡面實現了open等方法,接著為這個容器生成驅動模組,也就是register_chrdev函式,第乙個引數為主裝置號,如果為零,則核心為其分配主裝置號,即主裝置號大於0,第二個引數為裝置名,可以自行定義,第三個引數就是上面那個實現了open等操作方法的容器。接著建立類,通過類建立裝置(不大懂,現在只是照抄),最後宣告驅動入口函式,為了完整驅動解除安裝函式也宣告下啦 完畢!感謝韋東山老師!

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