Date: Fri, 21 Jul 2000 10:06:49 -0700 (PDT) From: John Baldwin <jhb@pike.osd.bsdi.com> To: Bruce Evans <bde@zeta.org.au> Cc: Warner@pike.osd.bsdi.com, Losh <imp@village.org>, dwhite@resnet.uoregon.edu, freebsd-current@FreeBSD.ORG Subject: Re: No /boot/loader Message-ID: <200007211706.KAA67811@pike.osd.bsdi.com> In-Reply-To: <Pine.BSF.4.21.0007211852440.2315-100000@besplex.bde.org> from Bruce Evans at "Jul 21, 2000 06:58:05 pm"
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Bruce Evans wrote: > On Thu, 20 Jul 2000, John Baldwin wrote: > > > No, that's wrong, too. A normal disk has a proper slice table (slices start > > on cylinder boundaries and do not contain the MBR, thus leaving the first > track > > cylinder unused). A truly dedicated disk (disklabel auto <foo>) uses a > track > > ... > > at all to the drive's geometry. As with truly dedicated mode, the MBR is > > actually contained in boot1, but in dangerously dedicated mode we use the > > slice table hard-coded into the boot code. This slice table has 1 slice > > which is 50000 blocks long, or 25000k. The rest of the disk is marked as > > unused even though it is, in fact, used. The fact that it works at all is > > due to brokenness on our part (we don't check that partitions in a disklabel > > fit in the parent slice) and also results in several hacks in various portions > > of the code where we have to check for such bogusness and work around it. > > No, that's wrong too :-) . We a lot of checking that partitions in a > disklabel fit in the parent slice. We clip partitions that don't fit in > various ways for backwards compatibility. > > Bruce Erm, maybe we clip partitions which aren't dangerously dedicated, but I've created test dangerously dedicated disks, and we certainly do not bother to actually change any of the slice information when we do so. disklabel(8) does for truly dedicated, but libdisk doesn't for dangerously dedicated. -- John Baldwin <jhb@bsdi.com> -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.cslab.vt.edu/~jobaldwi/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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