Hi,
One of the last messages remind me of a question a had a while ago
and never sorted out.
>From what I understand from reading IO-APIC.txt the purpose of the
kernel options pirq
is to correct the mp table passed by the bios to the kernel.
However they seem to do nothing other than printing some messages, the
mp table
is never modified...
When interrupts are being set up in bios32.c the function
IO_APIC_get_PCI_irq_vector
in io_apic.c is called and this only depends on the mp table entries.
It seems to me to effectively change something one has to modify the mp
tables entries.
I want to know if this following modifications are possible:
1.Setting a irq to xtpic mode (there was a patch that claimed to do this
but it doesn't work)
2.Interchanging two ioapic interrupts (just out of curiosity).
Finally, there is also a problem in the ordering of the pirq entries
which are opposite in two different places:
------------------------------------------------------------------------
for (i = 0; i < max; i++) {
printk("... PIRQ%d -> IRQ %d\n", i, ints[i+1]);
/*
* PIRQs are mapped upside down, usually.
*/
pirq_entries[MAX_PIRQS-i-1] = ints[i+1];
}
-------------------------------------------------------------------------
and
--------------------------------------------------------------------------
/*
* PCI IRQ command line redirection. Yes, limits are hardcoded.
*/
if ((pin >= 16) && (pin <= 23)) {
if (pirq_entries[pin-16] != -1) {
if (!pirq_entries[pin-16]) {
printk("disabling PIRQ%d\n", pin-16);
} else {
irq = pirq_entries[pin-16];
printk("using PIRQ%d -> IRQ %d\n",
pin-16, irq);
}
}
}
---------------------------------------------------------------------------
This doesn't matter much since the code doesn't actually do anything :-0
Rui Sousa
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