Re: [Qemu-devel] [PATCH v3 1/6] hw/misc/dyn_sysbus_binding: helpers for sysbus device dynamic binding

[Paolo Bonzini]

Il 10/09/2014 12:09, Alexander Graf ha scritto:
> Fair enough.
> 
> As far as moving "platform bus" logic into sysbus, I'd really like to
> hold back and see what this whole thing ends up getting used for first.
> 
> So for now, I'd definitely prefer to keep "platform bus" logic and
> "sysbus" logic separate. If we realize that every user only ever uses
> the dynamic sysbus creation in conjunction with our "platform bus"
> implementation, we can merge them.

I agree.  As you pointed out, we have two usecases:

1) arbitrary dynamic sysbus devices, because you're playing with board
design or because you're working on a virtualized platform

2) pluggable components in a fixed board design (e.g. CCSR)

The only thing they share is FDT creation.  The other part, which is
assigning the interrupts and memory regions, is different: case (1) has
it driven by command line or simply bottom-to-top; case (2) has it
driven by an implementation of a spec.

It's not even clear to me that E500 CCSR devices should be sysbus, in
fact...

Paolo