Hang on Reboot - Installing the OpenBSD 3.1 MBR - Complete Instructions

Guys - Please add this to the emBSD doc section or someplace so that those
wanting to RTFM, can actually have a M to read!?

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Title:  How to Update the Soekris net4501 to the OpenBSD 3.1 Boot Loader -
so as to avoid having to power-cycle the box upon reboot

Author:  David Simmons ([email protected])

Last Updated: 2002 June 13

The Situation:  When doing a soft reboot of the emBSD system, the system
will stop at "Using Drive:0 Partition: 3".  While the system will properly
boot if power-cycled (ie. disconnecting then reapplying power), this can be
a hassle if the box is located off-site and/or is not easily accessible.

The 'Fix':
Simple Answer - replace the MBR with the OpenBSD 3.1 boot-loader

Step-by-Step Answer - the problem with the simple answer, is that the
OpenBSD FAQ doesn't discuss how to load the 'normal' boot-loader, it just
goes into depth about what OTHER boot-loaders are available and how to
implement them. (SideNote:  For some reason, the Boot-Easy loader did NOT
work for me - hence the need to use the 'normal' loader).

To update the boot-loader on the net4501, you'll need to have access to the
OS of the net4501 - which is part of the catch-22 - if you HAD access, you
wouldn't need the boot-loader.  Here's how you can boot into the box without
the OpenBSD loader (while this will work, it's a manual fix and requires you
to have access to the comBIOS console) - submitted by Soren Kristensen:

	"First you might want to try the new builtin BIOS master boot
	loader, at the monitor prompt (accessed by typing CTRL-P)
	enter:

	> boot :X

	X can be 1 to 4, that will boot the X partition on the CF disk,
	assuming that the partition table is still there.... I believe
	that OpenBSD for some reason as default use partition 4, right?"

and yes, it works like a charm! (use the command "> boot :4" ).  Now that
you're into the OS, you'll need to get the MBR file from the OpenBSD 3.1
distribution (note: the OpenBSD FAQ will talk about getting a Boot.bin
file - this is for the alternate loaders - we're going to install the
original Master Boot Record (MBR)).  You'll need to download the base31.tgz
file from the ftp site (ie.
ftp.openbsd.org/pub/OpenBSD/3.1/i386/base31.tgz ) perferrably onto another
Unix machine.  At this point, we'll need to get the MBR file using the
command (after the 'gzip -d base31.tgz' command):

	tar -xvf base31.tar ./usr/mdec/mbr

This will extract the MBR binary into the sub-directory ./usr/mdec from
where-ever you are in your directory tree.  At this point, issue the
command:

	fdisk -i -f /(where-ever you are)/usr/mdec/mbr wd0

You'll need to answer the question:

Only LBA values are valid in ending cylinder for partition #3.

        -----------------------------------------------------
        ------ ATTENTION - UPDATING MASTER BOOT RECORD ------
        -----------------------------------------------------

Do you wish to write new MBR? [n]

and then get a normal prompt.  At this point, you can test if successful by
rebooting (by issuing the command:  "shutdown -r now" ).

Hope it works and we have less red foreheads....Dave

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