Subject: Re: i386 bootxx_ffsv1
To: Curt Sampson <>
From: David Laight <>
List: current-users
Date: 10/21/2003 12:47:23
On Tue, Oct 21, 2003 at 10:56:11AM +0900, Curt Sampson wrote:
> I recently set up a 64 MB USB flash device (which comes up as a
> standard sd0 USB mass storage device) with a DOS partition table,
> NetBSD partition, and the usual standard stuff you'd do if you were
> installing to a hard drive. I then put a /boot (from August 13th)
> and used installboot from that date to install an October 20th
> /usr/mdec/bootxx_ffsv1. (The one from the 13th just reboots my EPIC
> motherboard as soon as it loads--as do the latest floppies [October
> 20th], BTW.)

Do you mean that bootxx_ffsv1 has just got fixed?
And that the mbr code (or something else?) has just got broken?

The mbr code is a pain to debug :-( But problems are more likely
later on.
It would be useful to know hpw far it gets before the system reboots
itself.  The last message output would help - although it may not
be displayed for long.

> When I set my BIOS to boot from USB-ZIP, the first stage
> bootstrap seems to load fine, but it then says "cannot find /boot". The
> file is indeed there. Before I file a PR, does any one have any thoughts
> on what might be going wrong?

At a guess either the boot code is stomping on some memory the bios
wants to use, or a problem with the wrong x86 segment register
being used, or something to do with the top bits of a 32bit register
being assumed to be zero.

This can only be tracked down by someone with a failing machine (and
a lot of patience).


David Laight: