Re: Exposing ROM's though sysfs

Jon Smirl
2004-07-30T19:30:24Z

--- Matthew Wilcox <willy@debian.org> wrote:

> My problem is with this is the following passage from PCI 2.2 and PCI
> 2.3:
>
> In order to minimize the number of address decoders needed, a
> device
> may share a decoder between the Expansion ROM Base Address register
> and
> other Base Address registers. When expansion ROM decode is
> enabled, ...
>
> On Fri, Jul 30, 2004 at 11:59:21AM -0700, Jon Smirl wrote:
> > Alan Cox knows more about this, but I believe there is only one PCI
> > card in existence that does this.
>
> Strange; he was the one who pointed out this requirement to me in the
> first place and he hinted that many devices did this.

Alan, what's the answer here?

> Shutting off interrupts isn't nearly enough. Any other CPU could
> access the device, or indeed any device capable of DMA could

Another idea, it's ok to read the ROM when there is no device driver
loaded. When the driver for one of these card loads it could trigger a
copy of the ROM into RAM and cache it in a PCI structure.

=====
Jon Smirl
jonsmirl@yahoo.com

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