National Semiconductor Geode GX1 ?

Peter Stuge stuge-linuxbios at cdy.org
Sun Dec 1 13:11:01 CET 2002


On Sun, Dec 01, 2002 at 10:05:21AM -0700, Ronald G. Minnich wrote:
> I see no problem with putting vsa2 to rom. I just don't know how to use
> it :-)

E.g. via int 10h, or outb(0x220,..)..  VSA (and 2) is used to provide the
old software interface to the new hardware that works in quite different
(better, hopefully) ways.

When int 10h is called, or port 0x220 or 0x92 is accessed, an smint (system
management interrupt, found on mobile CPUs for suspending and so on) is
generated and the "low level" OS driver ends up talking to software instead
of hardware.  Practical and economic, when you grasp the concept.

Some VSA things are complete functions (xpressaudio, no sound will be heard
without the xpressaudio VSA ROM) while others are only one way to access
that particular feature (video BIOS, the framebuffer driver works as well
which means that the video BIOS isn't strictly needed although nice for boot
debugging) and yet others may be simple, optional, addons.


//Peter



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