> We could also deprecate the old port and use fwcfg for everything
> (try fwcfg, fall back to ae00).
>
fwcfg designed to be simple for easy use by firmware. It has two port
one for index another for value, so its use is racy in multi-threaded SMP
environment. DSDT code is executed in such environment. There is lock
facility in AML, but why complicate things.
> >> We could do this in two ways: by adding a fwcfg client to the DSDT,
> >> or by copying the information to system memory, and referencing
> >> system memory from the DSDT.
> >>
> >This is even worse. It requires some fixed address to be shared between
> >DSDT and Seabios (or alternatively Seabios will have to generate this
> >part of DSDT dynamically).
> >
>
> Could easily be something in the F segment.
>
Yes, but then we will have two magic values (fwcfg index + address
in F segment) instead of one (address of pci hot-plug controller).