Return to BSD News archive
Newsgroups: comp.unix.bsd Path: sserve!manuel!munnari.oz.au!mips!mips!darwin.sura.net!cs.ucf.edu!tarpit!newspost From: jbh@aii.com Subject: Re: 386bsd-0.1: primary bootstrap (wdbootblk.c) problem & fix. Message-ID: <1992Jul28.114831.29782@pixie.aii.com> Keywords: 386bsd boot bootstrap wdbootblk.c Sender: newspost@pixie.aii.com Organization: Automation Intelligence References: <1992Jul27.172708.3363@gateway.novell.com> <greg.712261295@hibp1.ecse.rpi.edu> <1992Jul27.192502.15727@gateway.novell.com> Date: Tue, 28 Jul 1992 11:48:31 GMT In article <1992Jul27.192502.15727@gateway.novell.com> terry@npd.Novell.COM (Terry Lambert) writes: >In article <greg.712261295@hibp1.ecse.rpi.edu> greg@ecse.rpi.edu (Greg) writes: >>Terry, please reread my message. THIS IS NOT THE SAME BUG!!!!!! >>This problem is in wdbootblk.c. The code contained in wd.c has not >>even been loaded off the disk at the point when this hang occurs! >>To understand what is going on, study wdbootblk.c. > > I think I goofed in recommending the wd.c fix for this problem; >however, the status register being polled after the delay is wd_status, >and I still believe that a canonical fix would be looking at wd_altsts >instead. You have totally missed it ! wd_altsts is BOGUS period. Read your IBM Tech ref. manual, the register is READ ONLY and only 4 bits wide. It ain't good for anything when bieng read !!!!! Read the Western Digital Manual, a read of this register is good only to provide a VENDOR ID number, on a REAL W.D. chip it ALWAYS returns a FIXED value regardless of the status of the controller. The 'patch' simply used wd_status to obtain the REAL status of the controller ! This is the proper way!!!!! > > Greg's delay loop will have the same effect -- that is, making sure >the controller has finished it's reset prior to using it. > The DELAY loop method is still dancing through raindrops and is NOT safe for ALL combinations of CPU-speed and MFM/RLL controllers. ====================================================================== Jim Huber jbh@aii.com or ...!tarpit!jbh Voice (407) 661-7017 Automation Intelligence,Inc. 850 Trafalgar Court Suite 200 Maitland, FL 32751 ======================================================================