AHCI(4) Device Drivers Manual AHCI(4)

ahci — Advanced Host Controller Interface for Serial ATA

ahci* at acpi?
ahci* at fdt?
ahci* at pci?
ahci* at jmb?

The ahci driver provides support for Serial ATA controllers conforming to the Advanced Host Controller Interface specification.

Several AHCI capable controllers also provide a compatibility mode that causes them to appear as a traditional ATA controller supported by pciide(4).

Although ahci controllers are actual ATA controllers, the driver emulates SCSI via a translation layer.

Setting the lowest bit (0x1) of the driver flags forces ahci to negotiate SATA 1 (1.5 Gb/s) transfer speeds only. It may be useful where higher speeds are unstable.

intro(4), jmb(4), pci(4), pciide(4), scsi(4)

The ahci driver first appeared in OpenBSD 4.1.

The ahci driver was written by David Gwynne <dlg@openbsd.org> and Christopher Pascoe <pascoe@openbsd.org>.

OpenBSD 7.8 July 2, 2018 AHCI(4)