AHCI(4) - Device Drivers Manual #

AHCI(4) - Device Drivers Manual

NAME #

ahci - Advanced Host Controller Interface for Serial ATA

SYNOPSIS #

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

DESCRIPTION #

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.

SEE ALSO #

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

HISTORY #

The ahci driver first appeared in OpenBSD 4.1.

AUTHORS #

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

OpenBSD 7.5 - July 2, 2018