The difference between kernel-mode drivers and user-mode drivers

tinghua

The difference between kernel-mode drivers and user-mode drivers [Copy link]

RT, I have been writing WinCE drivers for a while, but I am ashamed that I still don't understand the difference between kernel-mode drivers and user-mode drivers. I would like to ask for your advice.

youkezero

Help. ~! ! ! ! ! ! ! !

jinan1861

I am also ashamed. My biggest understanding is that the priority of kernel-mode drivers is higher than that of user-mode drivers. I learned from PB that the process address of kernel-mode is isolated from that of user-mode. Other things are too complicated. We can learn and improve together. I just read books before, but I didn’t really understand it deeply.

fanjia2008

I don't understand it either. I wrote ordinary drivers and didn't call setkmode, but it doesn't seem to matter now. Isn't it said that the access range needs to be restricted in the registry? I didn't write it, and I haven't seen that driver write it like this.

gongxuechun

Kernel-mode drivers have high permissions and can access all address spaces.

stephen-lu

Just started learning

草原屠狼

I recommend you to read two articles written by a great guy from the CE team. After reading them, you should understand kernel mode and user mode, as well as user mode drivers in CE6. CE6 Drivers: What you need to know http://blogs.msdn.com/b/ce_base/archive/2006/11/09/ce6-drivers_3a00_-what-you-need-to-know.aspx

kunkun0910

mark

hanpeibei

6.0 is the only difference

KingGod

5.0 is not divided into such fine details, I am ashamed.

Quote the reply of huangqibin888: RT, I have been writing WinCE drivers for a while, but I am ashamed that I still don’t understand the difference between kernel-mode drivers and user-mode drivers. I am here to ask for your advice.

yemeng0713

Learned

longzhuyiqi

Yes, WinCE6 is divided into user mode and kernel mode. User mode: The driver is loaded in the udevice.exe process. udevice.exe is a user-mode process like ordinary applications. When an application wants to interact with peripherals, it needs to forward the request to the corresponding driver through the operating system kernel. Such a request may need to repeatedly enter and exit the kernel many times, and also need to switch between different processes. The advantage is that the stability of the operating system is improved, and the entire operating system will not crash due to defects in a certain device driver. The disadvantage is that the efficiency of completing requests is too low. Kernel mode: The driver no longer needs to switch between different processes to complete a request, nor does it need to repeatedly enter and exit the kernel. The advantage is that the efficiency of the driver in kernel mode to complete the request will be greatly improved. The disadvantage is that any error in the kernel may cause the entire operating system to crash. It is recommended to run the driver in user mode when it is just written, and then change it to kernel mode after the driver is stable.