Re: ISA slot detection on PCI systems?

[David Weinehall <tao@acc.umu.se>]

On Thu, Jan 03, 2002 at 10:44:57PM +0100, Lionel Bouton wrote:
> Alan Cox wrote:
> 
> >>This would break things like cross-compilation. Not sure how many people
> >>use it though. You will have to be on the machine for which you intend
> >>to compile the kernel. If you are compiling the kernel for the same machine
> >>then it is the best thing to happen, provided the software doing the
> >>configuration for u is not broken
> >>
> > 
> > I'm really not too worried about Grandma cross compiling kernels
> 
> 
> ROTFL at the mental image of my Grandma configuring a cross-compiling 
> environment.
> 
> Eric, you said somewhere else in this thread that eventually we should 
> be able to make kernel configuration as easy as MAC configuration.
> 
> In short we can't.
> 
> MAC configuration is a dream we can't touch. The core hardware and most 
> importantly the mainboard firmware is done by the very same company that 
> develops the OS. I guess they didn't shout themselves in the feet and 
> made firmware and hardware with clean enough interfaces that they could 
> make hardware detection trivial.
> Even if they did mistakes, had bugs, they have the exhaustive list of 
> them and most probably can easily use workarounds.
> 
> Contrast this with the PC world : numerous mainboard manufacturers, bios 
> developpers, extension card manufacturers, Operating Systems, each with 
> their own bugs others desesperately try to work around...
> 
> The general case where all works ok (no bugs in dmi, pnp, ...) is the 
> exception and the land here is full of workarounds and dead ends if you 
> want to do hardware detection.
> 
> The worst case : the plain old ISA bus where you can't try to detect a 
> specific extansion card without risking to lock the system hard by 
> screwing some other type that is listening on ports you probed.
> 
> What I think we should try is to identify the most stable interfaces 
> (lspci works ok for most systems and would be of great help), use them 
> and let the user fill the gap (ISA/MCA/VLB/AGP bus switches for the 
> *user* is a great idea indeed).
> 
> We are quite PC centric here. But other archs are certainly far more 
> friendly to what you're up to.

At least MCA and NuBus can be autodetected, and I'm fairly confident
the people behind the VME-bus and TurboChannel weren't stupid either,
so those can probably be autodetected and probed too.

Dunno about VLB, but AGP is sort of a special-case of PCI (if I'm
not all wrong) and can be autodtected too.

ISA, on the other hand, is always a gamble. I bet there are other
exceptions as well.


/David Weinehall
  _                                                                 _
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