Stephen> PCI VGA devices have a fixed base address. This is a hideous
Stephen> hack of the PCI spec. in that the VGA space of a PCI video
Stephen> device sits at a fixed location in the PCI address
Stephen> space. Host pridges are expected to handle this, and
Stephen> PCI-to-PCI bridges generally have a bit to enable VGA support
Stephen> downstream.
Stephen> This is how it is possible for say the BIOS to find a display
Stephen> even before scanning the PCI bus, for example to draw those
Stephen> flashy configuration screens.
Stephen> So, it matters not whether PCI is scanned before console is
Stephen> configured.
As you say, for a PC style VGA board in a PC you can keep this
assumption, however some boards do not have the typical VGA mode and
runs as framebuffers only (I think the TGA is such a board). In this
case we need to be able to query the bus to find the board.
If there is no reason why the PCI should not be initialized before the
console I will suggest that we change the initialization order as
Geert suggested.
Jes