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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] Unified device model
Date: Sun, 9 Apr 2006 11:38:28 +0100
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To: qemu-devel@nongnu.org

> >>I am wondering about making unified device models architecture for open
> >>source simulators.
> >>The device models will be used in QEMU, Bochs, Xen and other open source
> >>simulators which would use the device models.
> >
> >I would support this idea, if it was possible.
>
> Why not ?
> You always could consider to add simple modules C++ to QEMU or build C++
> device -> C device interface bridge ...

I think to be acceptable to qemu (and probably also for Xen) the devices would 
have to be written in C. C++ is more pain that it's worth in this context.
Of course there's no reason why we couldn't use the subset of C that's also 
valid C++. You could also write C++ wrappers round the interface for bochs to 
use.

I'm not a fan of binary plugins (for the same reasons I'm don't like binary 
kernel modules), and don't think there's any real need to them. I can't see 
any good reasons why open source devices would need to be broken out into a 
separate shared library.

If you do want to accommodate proprietary binary plugins then C++ is a really 
bad idea. The C++/libstdc++ ABI simply isn't stable enough to make this a 
realistic option.

Paul