From owner-freebsd-hackers Tue Dec 22 08:37:57 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id IAA13694 for freebsd-hackers-outgoing; Tue, 22 Dec 1998 08:37:57 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from relay.mod.uk (relay.mod.uk [192.5.29.50]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id IAA13666 for ; Tue, 22 Dec 1998 08:37:54 -0800 (PST) (envelope-from druid@atc.dera.gov.uk) Received: from hermes.dra.hmg.gb by relay.mod.uk with local SMTP id ; Tue, 22 Dec 1998 16:37:47 +0000 Received: from atc.dera.gov.uk by hermes.dra.hmg.gb (MX V4.2 VAX) with SMTP; Tue, 22 Dec 1998 16:36:51 GMT Received: from atc.dera.gov.uk by atc.dera.gov.uk (8.8.8+Sun/SMI-SVR4) id QAA00685; Tue, 22 Dec 1998 16:36:36 GMT Message-ID: <367FCA84.3DBE8085@atc.dera.gov.uk> Date: Tue, 22 Dec 1998 16:36:20 +0000 From: Mark Templeton Organization: ATC Systems Group, DERA Malvern X-Mailer: Mozilla 4.05 [en] (X11; I; SunOS 5.6 sun4u) MIME-Version: 1.0 To: Mike Smith CC: freebsd-hackers@FreeBSD.ORG Subject: Re: Memory holes for ISA device drivers References: <199812141110.DAA00438@dingo.cdrom.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Mike Smith wrote: > > > OS is 2.2.5 > > Card is on ISA bus, preferably at 0xA00000. > > > > How do I create a (physical) memory hole for a card, > > as the card holds 64k shared memory? > > The target system BIOS does not support the 15-16M memory hole. > > pmap_mapdev() maps physical to virtual memory, but does not > > create a hole. > > > > How do I create a memory hole? > > This is chipset- and motherboard-specific. If you can't map the card > into the ISA 'hole' at 0xa0000, then you're SOL short of building a > custom PCI:ISA bridge (eg. using a PLX9050) and remapping it into PCI > space. Thank you for your comments, Mike. But even on systems that support the ISA memory hole, this restricts FreeBSD to effectively see only 15MB of RAM. Surely this is undesirable? Are there no software alternatives? If not, then I guess I have to talk to MRBIOS and see if they can supply me a BIOS which will do what I need. Mark. -- 0 00000000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 The Druid 0 B1013, DERA Malvern, Internet: Mark.Templeton@atc.dera.gov.uk St Andrews Road, Janet : Mark.Templeton@uk.mod.hermes Malvern, Worcs., WR14 3PS, Phone: +44-1684-894213 United Kingdom, Fax: +44-1684-894109 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message