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Date: Sun, 26 Jan 1997 20:59:33 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199701260959.UAA25500@godzilla.zeta.org.au>
To: bde@zeta.org.au, dgy@rtd.com
Subject: Re: suggestion for kernel printk() ?
Cc: freebsd-hackers@freefall.freebsd.org
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>> Yes, it would steal characters from the foreground console unless the
>> keyboard is dedicated to low-level console input.
>
>I guess a single character pushback isn't supported at that level?
>--don

Right.  The low level console driver is very primitive.  It does no
buffering.  Doing anything in it would have reentrancy problems, since
it may be called from interrupt handlers.  BTW, there _are_ reentrancy
problems in the syscons and pcvt output routines.  Don't use /dev/ttyv0
in syscons if you want the system to stay up forever.

Bruce