Plan 9 from Bell Labs’s /usr/web/sources/patch/applied/sdiahci-iaahcimode-ports/readme
Enable SATA ports 0 to 5 in sdiahci. See the "Intel I/O Controller Hub 9 (ICH9) Family Datasheet" document, section 14.1.31, "PCS Port Control and Status Register". http://www.intel.com/content/dam/doc/datasheet/io-controller-hub-9-datasheet.pdf