SDAHCI(3)SDAHCI(3)NAMEsdahci - AHCI (Advanced Host Controller Interface) SATA (Serial ATA)
storage device drivers
bind -a #S /dev
The sdahci driver provides access to AHCI devices via the sd(3) inter‐
face. The AHCI programming interface supports up to 32 hot-swappable
ATAPI or disk-like devices per controller. The legacy IDE interface
provided by sdata.c supports up to four drives which are not hot-swap‐
pable. Controller drive letters are assigned from onward.
AHCI controllers are detected automatically. Currently Intel and AMD
controllers are detected. Intel controllers need to have AHCI enabled
in the BIOS. For parts this typically means enabling enhanced mode and
AHCI. For ESB (Enterprise South Bridge) -based parts, only enhanced
mode needs to be enabled. Intel ich9-based AHCI does not support hot
swapping and drives must be connected to the lowest-numbered free port.
The top level control file, /dev/sdctl, supports the following control
messages for sdahci:
Toggle debug messages. Default is off.
Toggle printing of drive identification messages. Default is
on. Prints short messages when a drive is identified or
Print verbose ATAPI debugging messages. Default is off.
The device-level ctl file supports:
Send the ATA/ATAPI FLUSH CACHE command (0xe7 or 0xea). This
command may take up to 60 seconds to complete.
Send the ATA/ATAPI IDENTIFY DEVICE command (0xec). If device
information has changed, the new size, features and serial will
be noted. If changed, I/O on existing file descriptors will
result in the error string
Change the connection speed to one of auto, satai or sataii.
nop Send the ATA NOP command (0) if the device supports it. Per
standard, the result is always an error.
smart Send the ATA/ATAPI SMART RETURN STATUS command (0xda). This
will fail unless SMART is enabled on the drive.
Disable SMART on the drive. SMART is a persistent property of
Enable SMART on the drive.
Force a transition to the named state. The states are:
null ignored (may only be reached manually);
new powered down or newly discovered;
ready ready for commands;
reset being reset gently;
being fully reset;
device failed portreset (a port reset will be attempted
For devices present at boot, the transition is from state new to state
None of enclosure management, LED control and port multipliers are sup‐
ATAPI devices may not be reset when they have outstanding commands.