Re: IDSEL assignment

[Michael Richardson <mcr@solidum.com>]

>>>>> "Wilson" == Wilson Leung <wleung@arkon.bc.ca> writes:
    Wilson> How does a typical PC route the IDSEL pins?  Does it have a dedicated IDSEL
    Wilson> pin (possibly from a bridge device) for each PCI agent/slot? Or if the AD
    Wilson> lines
    Wilson> are used and tied to the IDSEL signals of each agent?

  The former. The bridge's control IDSEL. 

  The host bridge has some magic to control IDSEL, the PCI/PCI bridges
generate it in response to type 1 config cycles, generating a type 0 on
the secondary bus. 

  The host bridge's magic depends on the CPU, etc. but Intel host bridges
use I/O port 0x0C0 or some such.

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