Re: many in-tree xorg packages updated

[Matthias Drochner <m.drochner%fz-juelich.de@localhost>]

[pkgsrc/libpciaccess/patch-ac]

macallan%netbsd.org@localhost said:
> That reads the legacy VGA ROM and is indeed PC specific. Other archs
> will have to find its bus address from the ROM BAR, hope it's valid,
> enable it, map it etc.

I've found a reference for the concern I expressed in the commit msg:
PCI spec rev. 3.0 ch. 6.2.5.2 says:
> 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, the decoder is used for accesses
> to the expansion ROM and device independent software must not access
> the device through any other Base Address registers.

This means reading the ROM of an active device is somewhat hairy --
would be better to use the firmware's copy if possible.

best regards
Matthias

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