Kernel space? What the heck are you talking about?
There is a direct analog connection from the CD drive to the sound card.
It doesn't ever even touch the mother board. The signal sure as hell
isn't routed out through the soundcard to the motherboard, and then back
into the soundcard. No kernel, user, or any other sort of space is
involved. It's an analog signal, which isn't even representable in
kernel or user space unless you convert it to digital, which kind of
defeats the purpose.
No PCM, in any space.
Odds are pretty good that you can rig an Analog playback with a /fried/
motherboard, so long as you have some way of getting power to the sound
card, and one of those CD drives that has a play button on the front of
it. Might take some hacking, and I'm not up to it, but... definitely no
digital magic needed. Heck, throw out the _sound card_, and just press
play on the front of your CD, with your headphones jacked into the
front: it's the same signal.
Just to note, my motherboard although I've never gotten this feature to
work, has a BIOS toggle to enable the playing of CD's without booting
the computer just by keyboard shortcuts (I think my keyboard is
incompatible with the feature because of some weird hot key behavior)
