sudo gedit /etc/xrdp/startwm.sh 在. /etc/X11/Xsession 前一行插入 xfce4-session
sudo service xrdp restart
name=Reconnect
lib=libvnc.so
username=ask
password=ask
ip=127.0.0.1
port=5910
# modinfo softdog
filename: /lib/modules/3.2.0-4-686-pae/kernel/drivers/watchdog/softdog.ko
2. 加载模块
# insmod /lib/modules/3.2.0-4-686-pae/kernel/drivers/watchdog/softdog.ko
3. 此刻可见/dev/watchdog, 或创建
# mknod /dev/watchdog c 10 130
4. 查看dev并赋予权限
# ls -l /dev/watchdog
crw------- 1 root root 10, 130 Mar 21 16:27 /dev/watchdog# chmod o+rw /dev/watchdog
5. 测试使用watch dog
简单可写为：
# echo 0 > /dev/watchdog ///从此刻起计时，启用watchdog
# echo -n V > /dev/watchdog ///停用watchdog
6. 硬件与软件watchdog的区别
硬件watchdog必须有硬件电路支持, 设备节点/dev/watchdog对应着真实的物理设备， 不同类型的硬件watchdog设备由相应的硬件驱动管理。软件watchdog由一内核模块softdog.ko 通过定时器机制实现，/dev/watchdog并不对应着真实的物理设备，只是为应用提供了一个与操作硬件watchdog相同的接口。
硬件watchdog比软件watchdog有更好的可靠性。 软件watchdog基于内核的定时器实现，当内核或中断出现异常时，软件watchdog将会失效。而硬件watchdog由自身的硬件电路控制, 独立于内核。无论当前系统状态如何，硬件watchdog在设定的时间间隔内没有被执行写操作，仍会重新启动系统
看门狗是混杂设备，所以主设备号是10，/include/linux/miscdevice.h 中定义他的次设备号为130
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <signal.h>
#include <time.h>
#include <pthread.h>
#include <sys/time.h>
#include <linux/watchdog.h>
#include <sys/ioctl.h>
time_t backTime;
struct tm *pBackTime;
int wt_fd;
static void sigAlarm(int sig)
{
';
(void)time(&backTime);
pBackTime= localtime(&backTime);
printf("day: %d; hour: %d; min: %d; sec: %d\n", pBackTime->tm_mday, pBackTime->tm_hour, pBackTime->tm_min, pBackTime->tm_sec);
write(wt_fd, &flag, ); //Reset Watchdog 喂狗
alarm();
return;
}
int main()
{
char flag = 'V';
int ret;
;
if(SIG_ERR == signal(SIGALRM, sigAlarm))
{
perror("signal (SIGALARM) error");
}
wt_fd = open("/dev/watchdog", O_RDWR);
)
{
printf("Fail to open watchdog device!\n");
}
else
{
write(wt_fd,NULL,);
printf("Turn on Watch Dog\n");
ret = ioctl(wt_fd, WDIOC_SETTIMEOUT, &timeout);
if(EINVAL == ret)
{
printf("EINVAL Returned\n");
}
else if(EFAULT == ret)
{
printf("EFAULT Returned\n");
}
== ret)
{
printf("Set timeout %d secs success\n", timeout);
}
else
{
printf("Ret %d\n", ret);
}
}
alarm();
);
write(wt_fd, &flag, );
printf("Turned off Watch Dog\n");
close(wt_fd);
;
}
http://blog.sina.com.cn/s/blog_69a04cf401016gz4.html