Date: Tue, 15 Apr 1997 02:49:42 -0700 From: David Greenman <dg@root.com> To: "Daniel M. Eischen" <deischen@iworks.InterWorks.org> Cc: krygier@kph.uni-mainz.de, questions@FreeBSD.ORG Subject: Re: special memory device Message-ID: <199704150949.CAA19581@root.com> In-Reply-To: Your message of "Tue, 15 Apr 1997 04:40:36 CDT." <199704150940.EAA15971@iworks.InterWorks.org>
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>> >The problem I have, is that if I create a driver for this chip, >> >how do I ask the PCI support code for 4 consecutive 16MB regions >> >of the PCI bus? From what I can tell, the PCI code will only let >> >you map an address space as it is defined in the PCI configuration >> >space registers. For the Tundra Universe chip, the registers >> >that configure the special PCI slave image are not in the PCI >> >configuration space. >> >> The obvious question this raises is: How do you do address space conflict >> resolution if you ignore the assignments made by the PCI BIOS? > >Right. There should probably be a resource list to manage these >addresses. Drivers would have to call a set of common functions >in order to allocate PCI address space. The Tundra Universe chip >shares the PCI bus with a DEC 21240 and an Adaptec 7880, so I can't >allocate an address range without ensuring it doesn't conflict. In order to do this you'd have to go poking around in the PCI registers of all of the devices that were found and create the map. This doesn't sound like much fun. -DG David Greenman Core-team/Principal Architect, The FreeBSD Project
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