Subject: RE: PCIC interrupt selection
To: Harald Bjoroy <harald@bitcon.no>
From: Nathan J. Williams <nathanw@MIT.EDU>
List: port-i386
Date: 08/11/1998 13:17:16
>	There are no mods to the OS for the machine. The only difference
>is that the licensing pages tells the customer to call the hardware
>vendor for support, not M$. (Also some preloaded software and specific
>utilitysoftware sometimes, but you can always scrap the machine and
>install a blank OSR2, infact if you get a CD-ROM with the machine, it is
>a MS-printed OSR2 CD.)

	My error; as all the Win95 laptops I've seen come up with
custom splash screens and custom restore disks, I

>
>	There is definately some magic the OS does to boot the devices,
>and it is embedded in the PNP concept.

	[... windows configuration description snipped ...]
This sounds reasonably similar to what we do.

>	What NetBSD must do to fix this, is to compile in all drivers it
>needs to support, add a special driver for the PCMCIA controller which
>finds which cards are in the controller and then activates the correct
>driver based on the ID from the card. How to assign the correct
>resources I don't know, but I believe there is already code for this in
>the PNP support (?).

	This is exactly what our pcmcia code does already. But there are
two places where we lose:
	1) Resources used by devices we don't probe. This includes
things like sound cards and printer ports, whose drivers we leave out
of the install kernels due to size constraints. These usually stop
being a problem once the machine has a non-INSTALL kernel loaded, and
we could probably deal with them in the INSTALL kernels with some
agressive combination of "stub" drivers (to find what resources are in
use, without including the body of the driver code) and keeping track
of resource information we gather from other sources, such as the ISA
PnP configuration. 
	Can you do an over-the-network install of Windows? If not, it
suggests that they simply avoided this issue, and that their system
tries to avoid the problem of ever having devices without drivers for
them. 
	
	2) Resources that cannot be used on a particular system. This
is usually some irq that the system board has reserved for an device
which isn't always present. If what you say about the genericness of
Win95 installs is true, then there must be *some* way of dealing with
them, because it deals with them. Perhaps some
poking-at-the-interrupts magic that we've tried to avoid using to
date?
	
	- Nathan