Re: Re: Interrupt Handling

["sanjayk" <tousanjay@xxxxxxxxxxxxxx>]

hi clemens
I have a doubt, 
I have a ia32 uniprocessor machine.
whenever i try to compile my kernel 2.6 with SMP support enabled,
i don't see any option regarding APIC.
But when i try to compile it without SMP support, there appears
a option for LOCAL APIC support.

-IS APIC support selected by default for SMP kernel.
-I get the feeling that without smp support, arch/i386/kernel/i8259.c file is used for interrupt handling(if APIC support not selected), while for SMP aware kernel arch/i386/kernel/io_apic.c is the file used

please correct me if i am wrong

thanks and regard
sanjayk




On Fri, 10 Sep 2004 Clemens Buchacher wrote :
>On Thu, Sep 09, 2004 at 12:35:29PM +0530, Dhiman, Gaurav wrote:
> > In kernel source where can I find the code which actually identifies the
> > IRQ number by reading the APIC mask and status registers.
>
>If you are talking about the Intel architecture, no registers have to be
>read in order to determine the IRQ number. Every interrupt has an
>appropriate gate, which is initialized in arch/i386/kernel/i8259.c or
>arch/i386/kernel/io_apic.c.
>
>In order to understand interrupt handling would suggest studying the
>kernel sources and the appropriate reference manual of your
>architecture.
>
>Regards,
>Clemens
>
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