//nodevfs.c

#ifndef?__KERNEL__
#define?__KERNEL__
#endif

#ifndef?MODULE
#define?MODULE
#endif

#include?
#include?
#include?
#include?
#include????/*?printk（）?*/
#include????/*?kmalloc（）?*/
#include???
#include?????/*?error?codes?*/
#include?????/*?size_t?*/
#include?
#include?????/*?O_ACCMODE?*/
#include?????/*?COPY_TO_USER?*/
#include??????/*?cli（）?*_flags?*/

#define?DEVICE_NAME?“evan“
#define?evan_MAJOR?99
#define?evan_MINOR?0
static?int?MAX_BUF_LEN=1024;
static?char?drv_buf[1024];
static?int?WRI_LENGTH=0;

static?void?do_write（）
{
int?i;
int?len=WRI_LENGTH;
char?tmp;
for（i=0;i<（len>>1）;i++len--）
{
tmp=drv_buf[len-i];
drv_buf[len-i]=drv_buf[i];
drv_buf[i]=tmp;
}
}

static?ssize_t?evan_write（struct?file?*filp?char?*buffer?size_t?count）
{
if?（count>MAX_BUF_LEN）?count=MAX_BUF_LEN