[Beowulf] reboot without passing through BIOS?

[Mark Kosmowski]

>
> Message: 1
> Date: Thu, 31 Jul 2008 06:43:29 -0700
> From: "Lombard, David N" <dnlombar at ichips.intel.com>
> Subject: Re: [Beowulf] reboot without passing through BIOS?
> To: "Robert G. Brown" <rgb at phy.duke.edu>
> Cc: "Lombard, David N" <dnlombar at plxs0284.pdx.intel.com>,
>        "beowulf at beowulf.org" <beowulf at beowulf.org>,    David Mathog
>        <mathog at caltech.edu>
> Message-ID: <20080731134329.GA23066 at nlxdcldnl2.cl.intel.com>
> Content-Type: text/plain; charset=us-ascii
>
> On Wed, Jul 30, 2008 at 11:27:22AM -0700, Robert G. Brown wrote:
> > On Wed, 30 Jul 2008, David Mathog wrote:
> >
> > > David Lombard wrote:
> > >
> > >> On Wed, Jul 30, 2008 at 09:13:56AM -0700, David Mathog wrote:
> > >>> It then occurred to me that doing so would
> > >>> require a trip through the BIOS on every reboot, at least on every x86
> > >>> based computer I'm familiar with.
> > >>
> > >> Not since kexec was added to the kernel!
> > >
> > > That's exactly what I was thinking of for the Beowulf node problem.
> > > For instance:
> > >
> > >  http://www.knoppix.net/forum/viewtopic.php?t=27192
> > >
> > >> Beyond using kexec as described above, grub directly supports this; lilo
> > >> did too.
> > >
> > > I know how to do this by changing the configurations, but not how to
> > > specify a one time change that doesn't need to be manually undone later.
> > > Is either of these boot loaders capable of doing the logical equivalent of:
> > >
> > >  grub-next-boot-only -default 3
> > >
> > > (Override whatever default is in the config file, but just for the next
> > > boot.)
> >
> > There are several ways to accomplish this, and they can be automated.
> > For example, run a script at boot time that runs a script like
> > /etc/specialboot if it exists.  Then put:
> >
> > #!/bin/sh
> >
> > # cp /boot/grub/grub.conf.default /boot/grub/grub.conf
> > # cp /boot/grub/grub.conf.special /boot/grub/grub.conf
>
> According the the FM, there's a "grub-set-default" program that does
> the trick.  It supposedly creates a "default" file in the grub directory,
> nominally /boot, that causes grub to behave differently.  That's what I
> was alluding to in my first post.  Sadly, no such program exists in my F7.
>
> GIYF teaches us that the new method is:
>
>  # echo "savedefault --default=2 --once" | grub --batch
>  # reboot
>
> where "2" is the choice for your next one-time boot.
>
> I haven't tried this; I did use the LILO method when it was the bootloader
> of choice...
>
> --

>From KDE 3.5.x under OpenSUSE 10.x (and, presumably, 11.0) one can
choose which bootloader option to reboot to when reboot is selected.

Do the Windows requirements need 3-d graphics for the default booting?
 If not, would it be possible to boot into Linux and provide a virtual
Windows environment?

Or, setup the default boot to be Linux, then run a script* at Linux
boot to set the one-time next boot be to Windows.  This way, everytime
Windows reboots Linux would start and every time Linux reboots Windows
would start.

* How to exactly implement such a script is beyond the scope of my
current expertise, though I am more confident that this is possible,
mayhaps even easily possible, than I am that quantum mechanics is a
valid descriptor of the natural world.


Having posted this I will be rather embarrassed if this is the thread
that began as the non-ECC memory periodic refresh thread and not the
Windows-by-day / Linux-by-night thread.

Mark Kosmowski