On Thu, 27 Mar 2008, Benjamin Herrenschmidt wrote:Yeah, low IO is also reserved on PC's (the low 256 IO ports are motherboard resources and contain stuff like legacy DMA channel setup etc). You could imagine having it behind a PCI bridge, but in practice it's always on the NB/SB (and if you want to support some of the odder things like the NMI reason and the i387 error ports, they pretty much have to be - it would be insane to make a special PCI chips on a separate bus that does things like that). Linus --
