Date: Wed, 30 Sep 1998 11:00:45 -0700 (PDT) From: Tom <tom@uniserve.com> To: Karl Denninger <karl@Denninger.Net> Cc: Dan Nelson <dnelson@emsphone.com>, Alfred Perlstein <bright@hotjobs.com>, current@FreeBSD.ORG Subject: Re: Long IDE probes? Message-ID: <Pine.BSF.4.02A.9809301055290.7309-100000@shell.uniserve.ca> In-Reply-To: <19980930125458.A4304@Denninger.Net>
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On Wed, 30 Sep 1998, Karl Denninger wrote: > On Wed, Sep 30, 1998 at 10:31:25AM -0700, Tom wrote: > > > > On Wed, 30 Sep 1998, Karl Denninger wrote: > > > > > IDE by definition is probed by the BIOS before boot. Either the disk is > > > there or it is not, and you don't get out of POST and to Boot until that's > > > determined. Therefore, a long wait there is COMPLETELY pointless. > > > > Huh? First of all, more than disks can be put on IDE, and the BIOS > > doesn't know anything about that. Most BIOSes don't probe IDE at all, but > > newer ones do it to avoid static settings in the CMOS. > > The hell it doesn't. > > I've got several machines with IDE hardware in them. All of them find > things like CDROMs during the boot sequence (before loading an OS). Yes, newer machines. The BIOS doesn't need to do that. I have a CDROM in an older machine here, and the BIOS doesn't grok it at all. Basically, the BIOS display is informational only (except for the boot disk). > > > SCSI devices similarly are probed by the adapter BIOS. Again, there is no > > > reason for the long wait that I can fathom. > > > > For convienance only. Some adaptors don't probe. The adaptors don't > > make this info available to the OS in any way, because the OS is supposed > > to probe. > > The point isn't that probing is bad (its not). > > The point is that once the BIOS has taken the delay for spin-up, sent START > commands to SCSI disks, etc., waiting AGAIN is a waste of time. Hehe... that is pretty funny. I have a system here that will refuse to start after a power-start because the BIOS can't find the boot disk because it hasn't come ready yet. It is a SCSI disk, and the SCSI adaptor has probed it. I need to warm-boot the system at the "Please insert boot disk" message, and then it will boot from the hd. > Are the delay lengths reasonable? I don't know. Aren't there specs on > this stuff from the IDE and SCSI camps? The IDE delays just don't exist if you don't bother probing for devices that aren't there. The SCSI delay is 10 seconds. > -- > -- > Karl Denninger (karl@denninger.net) http://www.mcs.net/~karl > I ain't even *authorized* to speak for anyone other than myself, so give > up now on trying to associate my words with any particular organization. Tom To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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