> Have you forgotten? Linux/Unix has read configuration files for a *long* time.
> Anyway, isn't PnP based on probing the hardware (I'm ignorant in re PnP)?
>
Yes and no. I'm only slightly less ignorant than you, but maybe I can
fill in some gaps.
PnP isn't just probing the hardware, it's also defining where the
hardware will be. Instead of looking to see if a soundcard is at a
certain base address, we simply tell it that it is and have done with.
In many ways, this can simplify things and in many ways it can make them
far more diffcult.
The first thing that a PnP driver has to know about is where the PnP
devices that it finds are to be placed. In a fully PnP system, this is
fairly easy and addresses and ports can be allocated almost haphazardly
as long as one makes certain that they don't overlap. However, in the
real world, we have a number of non-PnP devices in every PnP system.
This added wrench makes life hellish for PnP initialization because we
have to pay extra special attention that we do not put a PnP device on
top of some legacy hardware or bad things can happen (especially as the
hardware can easily be very important, such as an ISA bridge or the
timer interrupt, and the system goes bye-bye for a while.) and this is
especially hard because all legacy devices may not be initialized until
used and we can step on the toes of hardware that is not in-use without
having any way of knowing. To this end, the standard (as far as I know)
is to maintain a device registry of some sort *between* boots that
records all the hardware (or just legacy hardware) on the system and can
be used as a table for knowing where to allocate PnP devices.
To be honest, I do not know what system the (2?) Linux PnP developments
are going. (The RedHat hosted one seems to be dead anyway.)
Also, many things that are called PnP do not fit into this idea. PnP
devices that work over serial lines (such as PnP printers) are no
different from regular printers except they support some status-readback
for identification. (Linux supports these, I think.) Also, PnP modems
have a nasty habit of being stripped down to the bare chipset and
requiring more expansive drivers than just setting up PnP values and
won't be supported in any of the PnP development crews. (Such as
WinModems)
Someone please correct me where I'm wrong, :)
Joe