The Nios 1 Linux Development Kit supported the CompactFlash slot and IDE header on the OS Support board using a modified version of the ATA controller from Opencores.org. DMA support was removed and the Wishbone interface was modified to Avalon.
Later on we tried putting DMA support back in and connecting a DMA controller. We had a little demo that served a couple web pages from the hard drive using DMA transfers. This was using a Nios 1 on Altera's Apex board. (This demo used the sample web server, not Linux)
Dennis
Microtronix Datacom