Irql

[blueshogun96]

Hey, does anyone have a good understanding of how Irql works on x86? I understand the general idea of Irql, but how does the system keep track of what the current Irql is? Is it normally kept inside of one of the registers (i.e. control register)? I tried searching google for this, but didn't find anything Thanks.

 

[Cyberman]

First suggestion when asking a question someone might not know the an acronym for don't use it? I could not understand what you were asking. Anyhow I just googled it so, do you mean IRQL == Interrupt ReQuest Level?
If so are you emulating the x86? Most times such things are handled by the kernel in the operating system. Unfortunately it is relative to what processor you are using. In simple terms it sets the priority of an interrupt and can allow an interrupt to .. interrupt an interrupt. (simple huh?)

What specifically are you wanting to do?

Cyb

PS I wish I documented my code more these days since I'm trying to use what I wrote a year ago and... I forgot what I was doing. :crazy:

 

[HyperIris]

I think you are talking IRQL, which is windows used in its kernel but not x86.
and if I'm not wrong, windows has 32 IRQL levels, they are from Power fail level to passive level.

You can find the detail in <Windows Internals> or some WDM driver book

 

[blueshogun96]

First suggestion when asking a question someone might not know the an acronym for don't use it? I could not understand what you were asking. Anyhow I just googled it so, do you mean IRQL == Interrupt ReQuest Level?
If so are you emulating the x86? Most times such things are handled by the kernel in the operating system. Unfortunately it is relative to what processor you are using. In simple terms it sets the priority of an interrupt and can allow an interrupt to .. interrupt an interrupt. (simple huh?)

What specifically are you wanting to do?

Cyb

PS I wish I documented my code more these days since I'm trying to use what I wrote a year ago and... I forgot what I was doing. :crazy:

Yeah, Interrupt ReQuest Level is what I was talking about and yes, I am emulating an x86 cpu. It's an Intel cpu that uses the P6 architecture. It's alot harder than most people think.

@HyperIris, I've been meaning to buy a wdm book for a while now. Guess I'll have to back on Amazon.com again!

 

[Cyberman]

Yeah, Interrupt ReQuest Level is what I was talking about and yes, I am emulating an x86 cpu. It's an Intel cpu that uses the P6 architecture. It's alot harder than most people think.[/qoute]
People assume the x86 is 'obvious' LOL
Hmmm you might want to hit Intel with the specific processor they tend to keep older data sheets a while even after the product is obsoleted. Another place to look is Bochs and Dosbox.
I believe the IRQL is set per interrupt but I have been wrong before (LOL). Need to know specifically which processor (P6 is quite far along in there lineup though.. mutliecore?)

@HyperIris, I've been meaning to buy a wdm book for a while now. Guess I'll have to back on Amazon.com again!

(mutter)

Cyb