Re: External monitor with Compaq Presario 1600
On Mon, Jul 07, 2003 at 11:20:02PM +0200, Arjen Verweij wrote:
> Welp, I recompiled a kernel without fb enabled, but when push comes to
> shove, I can NOT swap physical displays after choosing an option (i.e.
> one of the kernel image flavors) from the lilo menu. I am at a loss here.
>
> I'm inclined to think that if it is possible in the lilo menu, this should
> be possible without any special software, but then not being able to do if
> while the machine is booting/after it has booted leaves me flabbergasted.
>
> The reason why this functionality seems suddenly lost is completely
> unclear to me.
>
> Does anyone have suggestions on who to bother with this intriguing
> problem?
>
> Thanks.
> Arjen
Well, perhaps it is controlled by some code in the BIOS? Linux gets
into protected mode ASAP and tries to not look back at the BIOS ever
again - which means ordinary services like certain keys, running the
floopy, etc all have to be dealt with by the kernel. That's the only
theory I have that covers the feature dying during the kernel load.
For a reasonable analogy, laptop users whose floppy is really a USB
gadget, where the BIOS normally fakes things out so it looks like a
floppy... either need a kernel that really does have USB and USB-storage
built in, or can't use that floppy until the module is loadable. No
TomsRtBt for them unless they customize it.
Anyways if this is the case you might be able to do it *just as* the
kernel gets started, but not after very far in and all, and not able to
change the state after that.
You could, however, try compiling the /dev/nvram feature in and see if
you can see a diff in the results of reading it when you did switch it,
or didn't switch it, but did nothing else special to the bott process.
If so, maybe there's hope, since you can tickle /dev/nvram to hit the
signal (CAREFULLY! don't hit any other values - dd bs=1 and skip), and
see if it just... does the right thing.
* Heather Stern * star@ many places...
* Starshine Technical Services -*- 800 938 4078
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