[movitz-devel] Driver problems

Frode Vatvedt Fjeld ffjeld at common-lisp.net
Mon Jan 19 17:03:03 UTC 2004

Joel Smith <joels at mobyfoo.org> writes:

> I'm having some real problems writing a graphics driver for
> movitz. I need full 32bit data width for both reading and writing to
> the graphics ioports. Is there any sort of support for unboxed 32bit
> fixnums?

No, this is still one of the rather rough edges of Movitz. It needs to
be worked out sooner or later, but in the mean time, is it possible to
use a simpler mode with 8 or 16-bit IO access for the driver?

> My current kludge for this problem is to create a structure with two
> values to represent each half of the 32bits. This works nicely for
> writing to the ioports, but I can't figure out how to store the data
> read back from the ioports back into the structure's slots. How do
> you store data into a structure from within 'with-inline-assembly'?

It shouldn't be so difficult if you know assembly and look at the
definition of the movitz-struct class. But this kind of stuff is
likely to change, so again I think it'd be wiser at this point of
development to write at least one driver that is likely to work,
before doing something more optimized.

> By the way, is anyone interested in using movitz to write a proper
> LispOS? Is movitz going to stay purely a dev platform or is it going
> to turn into a full LispOS project?

I'd certainly like to see a LispOS happen (or two..), but somewhat
independently of Movitz itself, in a layered kind of way. Discussions
about the design of such an OS is something I'd like to see here on
the list. But I suppose Movitz needs to stabelize a bit before
something substantial happens on the OS level.

Frode Vatvedt Fjeld

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