.TH SDAHCI 3
.SH NAME
sdahci \- AHCI (Advanced Host Controller Interface) SATA (Serial ATA) storage device drivers
.SH SYNOPSIS
.nf
.B bind -a #S /dev
.sp 0.3v
.BI /dev/sdctl
.sp 0.3v
.BI /dev/sd En /ctl
.BI /dev/sd En /raw
.BI /dev/sd En /data
\&...
.fi
.SH DESCRIPTION
The
.I sdahci
driver provides access to AHCI devices via the
.IR sd (3)
interface.  AHCI devices use the ATA command set.
The AHCI programming interface supports up to 32
hot-swappable ATAPI or hard disk-like devices per controller.
The legacy IDE interface provided by
.B sdata.c
supports up to four drives which are not hot-swappable.
Controller drive letters are assigned from
.L E
onward.
.PP
AHCI controllers are detected automatically.
Currently AMD, Intel and nVidia controllers are detected.
Intel controllers need to have AHCI enabled in the BIOS.
For ICH (I/O Controller Hub)
parts this typically means enabling
enhanced mode and AHCI.
For ESB (Enterprise South Bridge) -based
parts, only enhanced mode needs to be enabled.
Due to hardware errata, Intel
.BR ich9 -based
AHCI does not support hot swapping and
drives must be connected to the lowest-numbered free port.
.PP
The top level control file,
.BR /dev/sdctl ,
supports the following control messages for
.IR sdahci :
.TF "\fLiahci idprint"
.TP
.B iahci debug
Toggle debug messages.  Default is off.
.TP
.B iahci idprint
Toggle printing of drive identification messages.  Default is on.
Prints short messages when a drive is identified or removed.
.TP
.B iahci aprint
Print verbose ATAPI debugging messages.  Default is off.
.PD
.PP
The device-level
.B ctl
file supports:
.TF \fLmode
.TP
.BI "mode " speed
Change the connection
.I speed
to one of
.BR auto ,
.BR satai ,
.BR sataii ,
or
.BR sataiii .
.TP
.BI "state " state
Force a transition to the named
.IR state .
The states are:
.RS
.TF portreset
.TP
.B null
ignored (may only be reached manually);
.TP
.B missing
not detected;
.TP
.B new
powered down or newly discovered;
.TP
.B ready
ready for commands;
.TP
.B reset
being reset gently;
.TP
.B portreset
being fully reset;
.TP
.B offline
device failed
.B portreset
(a port reset will be attempted periodically).
.RE
.PD
.PP
For devices present at boot, the transition is from state
.B new
to state
.BR ready .
.SH SOURCE
.B /sys/src/9/pc/sdiahci.c
.SH SEE ALSO
.IR atazz (8),
.IR sd (3),
.IR 9load (8)
.br
.BR http://download.intel.com/technology/serialata/pdf/rev1_3.pdf .
.SH BUGS
Enclosure management, LED control and port multipliers are supported.
.PP
ATAPI devices may not be reset when they have outstanding commands.