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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!news.mira.net.au!news.mel.connect.com.au!munnari.OZ.AU!news.ecn.uoknor.edu!news.cis.okstate.edu!newsfeed.ksu.ksu.edu!news.physics.uiowa.edu!math.ohio-state.edu!uwm.edu!lll-winken.llnl.gov!nntp.coast.net!fu-berlin.de!zrz.TU-Berlin.DE!zib-berlin.de!news.tu-chemnitz.de!irz401!uriah.heep!news From: j@uriah.heep.sax.de (J Wunsch) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Western Digital 2.5GB IDE HD doesn't work under FreeBSD ! Date: 11 May 1996 12:36:18 GMT Organization: Private BSD site, Dresden Lines: 31 Message-ID: <4n21k2$rjj@uriah.heep.sax.de> References: <aak2.830530576@ra.msstate.edu> <4m3dua$3db@uriah.heep.sax.de> <4m56qj$nc@anorak.coverform.lan> <4mdcdu$hqu@uriah.heep.sax.de> <4msub4$21u@anorak.coverform.lan> Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) NNTP-Posting-Host: localhost.heep.sax.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: knews 0.9.6 X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E brian@awfulhak.demon.co.uk (Brian Somers) wrote: > So does FreeBSD use logical block numbers in non-"dangerously dedicated" > mode ? FreeBSD does always use logical block numbers inside the kernel. Drivers for obsolete hardware (IDE :) have to convert them to C/H/S values to comply with the WD-1007 register file specifications. > Are the C/H/S translations relevent at all or does FreeBSD just > look at the logical sector field when fathoming the partition table ? The C/H/S values from the fdisk table (no, it's ``slices'', not ``partitions'' for us) are only picked up by the MBR, since their format is such that they can be directly passed to an int 0x13 disk read BIOS call. The limiatations of the 24-bit C/H/S values don't allow to really use it, so the slice size (and offset) are taken from the 4-byte numbers. > If this is the case, how come fdisk allows the user to change them ? Why should fdisk not allow it? ``You get what you want.'' Changing them might make sense e.g. to convert an fdisk table to a new C/H/S translation scheme of your BIOS. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)