IRQ detection

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pini

IRQ detection

Post by pini »

As read in the Linux Kernel Book, only IRQ 0 (timer), IRQ 2 (cascade) and IRQ 13 (fpu if present) are ia32 (i386+)-fixed.
Here comes my question : how is it possible to detect which hardware will send which IRQ?
So how can I detect the keyboard IRQ for example ?
Peter_Vigren

Re:IRQ detection

Post by Peter_Vigren »

In this text, there is a list over the IRQ:s... it is not only those three that is fixed...

http://osdev.neopages.net/tutorials/irqs.php
pini

Re:IRQ detection

Post by pini »

Peter_Vigren wrote: In this text, there is a list over the IRQ:s... it is not only those three that is fixed...

http://osdev.neopages.net/tutorials/irqs.php
What is shown only corresponds to some "standard" connection.
I guessed that, according to the intel manuals, any hardware combinaison could be made with any IRQ and that only IRQ #0, #2 and #13 were fixed. I agree that this combining is the most popular, but until I can't get absolutely sure of this, I may try to detect the IRQs by myself. I was asking for such help (maybe someone has already thought about it and could help ?).
pini

Re:IRQ detection

Post by pini »

Another reason of detecting the IRQ corresponding to specific hardware is that many hardware can share the same IRQ. For example, my configuration lets my ethernet and my sound card share the IRQ #10
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df
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Re:IRQ detection

Post by df »

i use the PCI config space to tell me what IRQs are going to what devices, etc.
-- Stu --
Slasher

Re:IRQ detection

Post by Slasher »

would that help with other type of devices like ISA?
pini

Re:IRQ detection

Post by pini »

df wrote: i use the PCI config space to tell me what IRQs are going to what devices, etc.
Could you explain or give me a link where this is explained ?
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