This isn't my area of expertise, but you might want to look into YhLu's work on the Tyan mainboards concerning the Silicon Image serial ATA controller.
This has been a problem for a long time with things like SCSI controllers as well.
On Wed, 26 May 2004, Jacob Alifrangis (LISTS) wrote:
How does linuxbios handle add-in cards that may need special boot-roms like the promise raid controllers, if I am going to startup from one?