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Cc: hackers@freebsd.org
Subject: Re: Active slice, only for a next boot
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"Dieter BSD" <dieterbsd@engineer.com> wrote:

> If you neglected to specify RS-232 console in the requirements,
> there is this thing. ??I haven't tried it.
> http://www.realweasel.com/

Heard of it, aka the PC Weasel.  I've never actually seen one.  They
have been around for a while; the original -- which they apparently
still make -- was ISA.

> Somebody probably sells a KVM-over-IP box.

Raritan, at least.  Probably others also.

> > Unfortunately it doesn't have a better way to do this as the
> > only input it gets from boot0 or any other MBR boot loader is
> > the BIOS drive number in %dl.  I'm not sure how else you would
> > detect that a non-active slice was booted from when that is
> > your only input.
>
> The NetBSD boot code manages to do it.

Dunno how NetBSD does it, but one approach that comes to mind would
be for whatever installs boot1 to set one of its bytes to the slice
number in which it is installed.