SDAHCI(3)

NAME

sdahci − AHCI (Advanced Host Controller Interface) SATA (Serial ATA) storage device drivers

SYNOPSIS

bind -a #S /dev
/dev/sdctl
/dev/sdEn/ctl
/dev/sdEn/raw
/dev/sdEn/data
...

DESCRIPTION

The sdahci driver provides access to AHCI devices via the sd(3) interface. 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-swappable. Controller drive letters are assigned from E onward.

AHCI controllers are detected automatically. Currently Intel and AMD controllers are detected. Intel controllers need to have AHCI enabled in the BIOS. For ich 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:

iahci debug Toggle debug messages. Default is off.

iahci idprint Toggle printing of drive identification messages. Default is on. Prints short messages when a drive is identified or removed.

iahci aprint Print verbose ATAPI debugging messages. Default is off.

The device-level ctl file supports:

flushcache Send the ATA/ATAPI FLUSH CACHE command (0xe7 or 0xea). This command may take up to 60 seconds to complete.

identify 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 media or partition has changed.

mode speed 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.

smartdisable Disable SMART on the drive. SMART is a persistent property of the drive.

smartenable Enable SMART on the drive.

state state Force a transition to the named state. The states are:

null ignored (may only be reached manually);

missing not detected;

new powered down or newly discovered;

ready ready for commands;

reset being reset gently;

portreset being fully reset;

offline device failed portreset (a port reset will be attempted periodically).

For devices present at boot, the transition is from state new to state ready.

SOURCE

/sys/src/9/pc/sdiahci.c

BUGS

None of enclosure management, LED control and port multipliers are supported.

ATAPI devices may not be reset when they have outstanding commands.

Plan 9 — December 08, 2011

Museum