Date: Wed, 4 Oct 2000 15:47:25 -0700 (PDT) From: Matthew Jacob <mjacob@feral.com> To: Doug Rabson <dfr@nlsystems.com> Cc: Wilko Bulte <wkb@freebie.demon.nl>, FreeBSD-alpha mailing list <freebsd-alpha@FreeBSD.ORG> Subject: Re: max memory on Alpha? Message-ID: <Pine.BSF.4.21.0010041546220.60871-100000@beppo.feral.com> In-Reply-To: <Pine.BSF.4.21.0010042339430.94692-100000@salmon.nlsystems.com>
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On Wed, 4 Oct 2000, Doug Rabson wrote: > On Tue, 3 Oct 2000, Wilko Bulte wrote: > > > What is the currently max supported memory size on Alpha? 2Gb maybe? > > Or will 4Gb also be OK? > > > > Reason for asking is that I want to try a AS8400 who is equipped > > with 3x 4Gb memory module. > > Currently we are limited to 1Gb or 2Gb, depending on the platform. The > tsunami driver uses a 2Gb window for dma and I think AS4x00 and AS8x00 > also support 2Gb. > > Supporting more memory requires that all dma capable hardware is the > busdma interface in its drivers. Given that, someone needs to write a > small amount of code in busdma_machdep.c to either bounce transfers down > to the 2Gb range or to use the sgmap to map the transfers into a reachable > place. Some SGMAP stuff is initialized- but you're right about dma-busifying. I'm about ready to shove an extra 512 MB memory module into an 8200 to take it to 2.5GB just to see what'll happen. -matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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