I finally installed it!
The I/O problems I got were using the controller in legacy mode. But in
AHCI mode the install CD wouldn't boot ("PBS1...Bad format or I/O error").
So I built a 9pcflop.gz wich included the sdiahci driver and used it
instead of the one included in the floppy install image.
Thank you, Erik, :) it seems that your driver is working perfectly. The
problem must be in the driver Plan 9 uses when the controller is working
in legacy mode (I suppose sdiahci isn't responsible for that).
Apart from that, I had problems with multiprocessor mode (but I think
it's because I use the vesa video driver). And I had problems also with
the kernel the installation copied, wich seemed to use kfs instead of
fossil.
Why doesn't install floppy include the sdiahci driver?
I don't know if other people have problems installing Plan 9 because of
this. In my case, the main problem was that install CD wouldn't boot in
AHCI mode. And if I didn't use AHCI, I got I/O errors during install.
Armando.