Re: ibm4xx pci (Re: IBM405GP/GPr OPB bus_space endian (powerpc/ibm4xx/dev/opb.c))

[Allen Briggs <briggs%netbsd.org@localhost>]

On Wed, May 10, 2006 at 07:35:29PM +0900, Shigeyuki Fukushima wrote:
> Why is pchb below on plb directly?
> (cf. On i386 port, mainbus -> pci -> pchb.)

On a number of ports, the PCI host bridge is the device through
which you access the PCI bus.  It's not the same on i386 systems.
I *think* that internally most PCs have a bus that isn't really
PCI, but which looks like PCI to software.  It's this that the
pchb really attaches itself to.

In any case, on i386 port, it's more:
     mainbus -> pci -> pchb -> pci -> ...

-allen

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