Re: [Qemu-devel] [PATCH 3/4] Stellaris machine config

[Markus Armbruster <armbru@redhat.com>]

Jamie Lokier <jamie@shareable.org> writes:

> M P wrote:
>> So now, with qdev, it's all official, /every value, constant, and
>> bitfield/ is hard coded, in hex, into a different non-code file, with
>> no way of derivating or overloading from.
> [...]
>> In fact,
>> the stellaris share /a lot/ between themselves, and there is not a
>> single shared line between your two stellaris boards definition file.
>
> This is a good point.
>
> I guess FDT is missing a "#include" equivalent, and possibly name
> constants.
>
> That isn't surprising given FDT's original use, to pass an entire
> machine description to a running kernel.
>
> But for QEMU, some way to give names to, say, a standard SoC or a
> basic board, or a PC without peripherals, and then refer to them in
> another FDT tree, would be useful.
>
> Whether it's done in QEMU itself or by preprocessing doesn't matter.
> Preprocessing would have the advantage that it would output FDTs that
> could, maybe, be passed to the guest kernel and just work.  Or maybe
> QEMU can have a tree preprocessor built in.
>
> -- Jamie

The need for an FDT to pass to the kernel doesn't dictate that we must
use it as configuration file.  FDT could be generated from the internal
machine description.