Date: Tue, 12 Jan 1999 03:54:18 +0200 (SAT) From: Robert Nordier <rnordier@nordier.com> To: nugundam@la.best.com (Joseph T. Lee) Cc: rnordier@nordier.com, tugrul@ianai.BlackSun.org, axl@iafrica.com, bright@hotjobs.com, freebsd-current@FreeBSD.ORG Subject: Re: Booting FreeBSD beyond the 1024th cylinder Message-ID: <199901120154.DAA01853@ceia.nordier.com> In-Reply-To: <19990111165214.C27416@la.best.com> from "Joseph T. Lee" at "Jan 11, 99 04:52:14 pm"
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Joseph T. Lee wrote: > On Tue, Jan 12, 1999 at 01:56:15AM +0200, Robert Nordier wrote: > > Booting FreeBSD beyond cylinder 1023 is not currently supported. > > > > Support, by way of the IBM/Microsoft int 0x13 extensions, was > > present in the new bootblocks a few months ago but was removed: > > too many BIOSes don't implement this stuff properly. > > Couldn't this be added somehow as an option, or get autodetected? > I've noticed my adaptec board can detect 0x13 extension support. We did used to detect support (int 0x13/0x41 returns an API subset support bitmap), but too often support was present but broken. As an example of the kind of problem: there's a recent Dell Optiplex GXa here which does support the extensions OK, but only if BIOS disk geometry is set to "auto"; otherwise, support is still claimed but it doesn't work (a divide error exception results). What is really needed (and this is the approach Microsoft adopts) is a real or V86 mode utility which runs tests before enabling support. But this doesn't slot neatly into FreeBSD's current installation model. The new boot manager (boot0) does support int 0x13 extensions as an "at own risk" option. In a few months, once everyone has successfully migrated to the new boot code and has confidence in it, we may introduce this as an option (given sufficient demand). -- Robert Nordier To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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