Date: Wed, 6 May 1998 07:41:46 +0200 (MET DST) From: Luigi Rizzo <luigi@labinfo.iet.unipi.it> To: archie@whistle.com (Archie Cobbs) Cc: stefan@promo.de, freebsd-hackers@FreeBSD.ORG Subject: Re: ISA-PnP w\o BIOS support? Message-ID: <199805060541.HAA09666@labinfo.iet.unipi.it> In-Reply-To: <199805060605.XAA22438@bubba.whistle.com> from "Archie Cobbs" at May 5, 98 11:05:22 pm
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> Not deliberate.. just forgot :-) > > > In any case there are two major problems in my view: > > 1) to do automatic resource assignment you'd need to know which > > resources are available. Maybe the bios knows (more or less, since > > legacy isa devices with no driver cannot be easily detected, and the > > PnP detection of conflicts i am not sure how well it works), > > but i have no idea on how to fetch this info > > Couldn't the config file account for all of the resources in use? no. what is available and what is not depends on the hardware. as someone else (Mike ?) mentioned, if you put your own non-pnp card in a pc and the bios/os/whatever doesn't know how to use it, the card will be undetected until a conflict occurs. The PnP spec have a way to detect conflicts but i am not sure it can really work because it depends on how the non-pnp card uses resources (e.g. it could be listening for some data before enabling its outputs; since the conflict detection can only work if the unknown card drives the output lines, in this case the detection will fail). so basically the problem is not solvable automatically. By the time you igve hints to the os on which resources are free, you could as well assign resources to the pnp devices which need them. > I mean, if the kernel doesn't know about some interrupt being used, > then who else is using it and what the heck for? I guess I don't > completely understand this issue. see above. > > 2) providing a configuration in the kernel config file via "device..." > > entry is hard, since a single pnp device can have 8 io ports, 2 drq, 2 > > irq, 4 memory addresses ... how do you fit this info in the few bits > > available on the "device" line ? > > Fix "config" to handle it. In the meantime, don't support devices > that use more than the "normal" number of resources. that means do not support audio cards, which are the ones where PnP is mostly needed. no thanks :) cheers luigi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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