PCI scanning and devices initialization

Juergen.Beisert at windriver.com Juergen.Beisert at windriver.com
Wed Aug 18 23:28:11 EST 2004


Hi,

> Yes, there may be something wrong with your hardware.

This could only be _one_ reason

> At the PCI init, PCI devices don't yet have an address, so the host
> detects them using configuration cycles. Theses uses a different
> addressing scheme, using each address line as a kind of "chip select".
> So the devices know the host is "talking" to it just by
> looking at it's
> IDSEL line going asserted. If on your board the IDSEL isn't wired
> properly then it won't work. Hopefully if that's the case,
> you can just
> wire it by hand, it's not a high speed signal.

Does the U-Boot PCI setup routine handles PCI devices behind a "PCI to
anything" bridge? Sometimes simple code ignores bridges. Don't know the
current U-Boot implementation. If not, there is no chance to access any
devices behind it (even if the hardware is correct).

JB

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