AHCI(4) | Device Drivers Manual | AHCI(4)

# 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>.

July 2, 2018 | Debian