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- Path: sparky!uunet!dtix!darwin.sura.net!cs.ucf.edu!tarpit!newspost
- From: jbh@aii.com
- Newsgroups: comp.unix.bsd
- Subject: Re: 386bsd-0.1: primary bootstrap (wdbootblk.c) problem & fix.
- Keywords: 386bsd boot bootstrap wdbootblk.c
- Message-ID: <1992Jul28.114831.29782@pixie.aii.com>
- Date: 28 Jul 92 11:48:31 GMT
- References: <1992Jul27.172708.3363@gateway.novell.com> <greg.712261295@hibp1.ecse.rpi.edu> <1992Jul27.192502.15727@gateway.novell.com>
- Sender: newspost@pixie.aii.com
- Organization: Automation Intelligence
- Lines: 34
-
- 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.
-
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