From owner-freebsd-alpha Thu Apr 15 12: 1:10 1999 Delivered-To: freebsd-alpha@freebsd.org Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by hub.freebsd.org (Postfix) with ESMTP id B367F14CE7 for ; Thu, 15 Apr 1999 12:00:57 -0700 (PDT) (envelope-from gallatin@cs.duke.edu) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.9.1/8.9.1) with ESMTP id OAA19541; Thu, 15 Apr 1999 14:58:06 -0400 (EDT) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.9.3/8.9.1) id OAA98011; Thu, 15 Apr 1999 14:58:03 -0400 (EDT) (envelope-from gallatin@cs.duke.edu) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Thu, 15 Apr 1999 14:58:03 -0400 (EDT) To: "Kenneth D. Merry" Cc: chuckr@picnic.mat.net (Chuck Robey), erik@habatech.no, scot@london.virgin.net, freebsd-alpha@FreeBSD.ORG Subject: Re: Installing FreeBSD on 164SX board In-Reply-To: <199904151843.MAA04069@panzer.plutotech.com> References: <199904151843.MAA04069@panzer.plutotech.com> X-Mailer: VM 6.43 under 20.4 "Emerald" XEmacs Lucid Message-ID: <14102.13297.626836.703289@grasshopper.cs.duke.edu> Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Kenneth D. Merry writes: > > One odd thing that happened when we stuck the 7891 (it's a 64-bit board) > board in the Miata was that SRM wouldn't load while the board was in a > 64-bit slot on the primary PCI bus. It gave some error about an > unrecognized SCSI controller or something along those lines. It did work > when we moved the board onto the secondary, 32-bit PCI bus. Congratulations, you have an old, broken-pyxis Miata which has the dma bug (you can't do a dma read across an 8k page boundary). The 64-bit slots are directly on the primary PCI bus, the 32-bit slots are behind a PPB which breaks up dma transactions so that they don't cross page boundaries. On machines with the DMA bug, the SRM console has been hacked to prevent users from putting boards into the 64-bit slots which might trigger the bug (eg, anything that they're not certain WON'T trigger the bug). If a cam driver won't trigger this bug, and you want to put the card in a 64-bit slot (and you may want, if you have a 21052 ppb) you can turn this feature off on a per-card basis by using 'set pci_device_override ' at the srm console prompt (before moving the board). Cheers, Drew ------------------------------------------------------------------------------ Andrew Gallatin, Sr Systems Programmer http://www.cs.duke.edu/~gallatin Duke University Email: gallatin@cs.duke.edu Department of Computer Science Phone: (919) 660-6590 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message