[PLUG] Ethernet Activation Question

[Kyle Hayes]

On Monday 23 December 2002 01:30, Fedor G. Pikus wrote:
> One passes parameter to the kernel at boot.
> I've only done it in a PC which had two cards of the same make, the
> parameter there was something like this:
> ether=5,0x220,eth0 ether=3,0x280,eth1
> so you tell the kernel which one is eth0 and which is eth1 by IRQ, not
> by card model (I don't know if you can tie eth0 to the card model or
> not, does not seem to be any place for it in the syntax of ether
> option). The simplest way to find the IRQ and IO address is to boot the
> kernel without thethe parameters, run ifconfig and see what you have
> there, it's under Interrupt: and Base address:.
> Of course if cards get moved around (or on PCI bus IRQs get reassigned)
> you're kind of screwed, so I suggest keeping an entry in lilo to boot
> the kernel without these options (just in case probing the old IRQ under
> new configuration hangs the kernel). With GRUB it's less of a problem
> because you can edit its bool lines duiring boot.

Hmm, I've run into this somewhere.  I think that it is actually the ports 
that control it.  At least for ISA cards!  I had a problem with this with 
some firewalls once.  There was a discussion of this on the kernel list a 
long time ago, but I cannot seem to find it in Google right now...

<from memory>
I think the probing part is done separately from the assignment to a 
specific ethX.  Once the probes are done and the right drivers are set up, 
I believe that the kernel assigns the ethX entries based on increasing 
port number.  Again, this is for ISA. Not sure about PCI.
</from memory>

You'd have to look a the code or find something in a kernel book or online 
to be sure.

Best,
Kyle