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Date: Fri, 24 Jan 1997 19:24:43 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199701240824.TAA07251@godzilla.zeta.org.au>
To: dgy@rtd.com, freebsd-hackers@freefall.freebsd.org
Subject: Re: suggestion for kernel printk() ?
Sender: owner-hackers@FreeBSD.ORG
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>     I just spent some time fighting a kernel that died miserably
>on boot  :-(  I was inundated with an endless stream of kernel
>messages (in highlighted text) followed promptly by a hard reset.
>It was quite frustrating to find that there doesn't seem to be a
>mechanism to pause the display at this point!

I use a serial console and `terminalprogram | tee foo' to capture
the output.

>     OK, reboot from /kernel.old and look through the logs.  Hmmm...
>nothing here!  Probably the filesystem wasn't even functional when
>the boot ran into trouble.

Boot messages are supposed to be preserved in the message buffer
across reboots.  However, many PC BIOSes and/or memory systems do
something that invalidates the message buffer even for a soft reboot.

Bruce