Explanation of Kernel & User mode, Class drivers, VDD, H

[leechat2001]

clear my doubts please?

Hi all,
I need answers for each of these

What is the difference between Kernel Mode and User Mode?
What is Virtual Device Driver (VxD or VDD)?
What are Class Drivers? ( I am interested in this? )
What is the entry function for a Device Driver like void main() in C programming?
What are Dispatch Routines?
What is an IRP and IRQL?
What is HAL how it look like, How many different HALs are there in Win2K?

Thanks
leechat2001

 

[djalli]

clear my doubts please?

Class drivers are the one used for new devices as smart cards, USB, firewire, etc. What is something is that it becomes a general purpose driver for any kind of smart card or USB for example.

You will not need a vendor specific driver to come with some installation CD. Actually these exist for USB and smart cards. They are part of MS Win operating systems.
Plug any USB storage drive in your USB port and VOILA! it works!

djalli

 

[leechat2001]

Re: clear my doubts please?

Thanks for your reply..!
Can anyone clear other doubts as well

Thanks
leechat2001

 

[davorin]

Re: clear my doubts please?

Moved here from "Elementary electronic questions"...dunno how to hell you thought it fits there!!!

Please ask such questions in the future one of those thousands wintel developer forums...this is an EDA forum...

 

[cawan]

clear my doubts please?

I can answer three of your questions:

1. What is the difference between Kernel Mode and User Mode
ans: Kernel Mode (Ring-0 in x86, Kernel in Alpha) is the operation mode allowed to access kernel api for memory access and I/O operation. User mode (Ring-3 in x86, User in Alpha) is the common application mode implemented by application programming.

2. What is Virtual Device Driver (VxD or VDD)?
ans: Virtual Device Driver is VDD. VxD is one of the driver model in win98.

4. What is the entry function for a Device Driver like void main() in C programming?
ans: DriverEntry()

 

[cent24.3]

clear my doubts please?

Hello, one other,

What is HAL how it look like, How many different HALs are there in Win2K?

Hardware Abstraction Layer is THE layer you go thru to acces the hardware under W2K/NT/XP.

 

[sshahid47]

clear my doubts please?

hi,
HAL or Hardware abstraction layer is the layer through with u access the actual hardware on Windows, the reason to provide to have this layer is u can have different hardware from vendors installed on ur pc, but we generalize the functionality by abstracting a layer and that layer assumes that a limited amout of functionality will always be present.