devb-ahci

Note: You must be root or have the right abilities to start this driver.

Syntax:

devb-ahci [cam option[,option]...]
          [mem option[,option]...]
          [ahci option[,option]...]
          [blk option[,option]...] &

Runs on:

QNX Neutrino

Options:

Note: Use commas (,) to separate the options. You can put the cam, mem, ahci, and blk groups of options in any order.

cam options

The cam options control libcam.so. If specified, they must follow the cam keyword.

mem options

name=tname: The typed memory name to use. This option lets you restrict the driver to use memory only from a particular region, which is often necessary for DMA and smmuman. If you set this option, it can benefit performance to set the same option in the blk layer as well, depending on the size of the typed memory region. The cam layer will move data between the blk layer and the typed memory.
Note: It's up to the startup to set up typed memory. For more information, see “Typed memory” in the “Interprocess Communication (IPC)” chapter of the System Architecture guide.

ahci options

The ahci options control the driver's interface to the AHCI controller. If you've installed multiple controllers, you can repeat these options for each controller. Remember, however, to specify the ahci keyword before each controller's set of options.

Interface-specific options:

did=did

The device ID of the controller.

ioport=addr

The address of the interface.

irq=req

The interrupt used by the controller.

nobmstr

Don't use busmastering. Specify this option if you want to disable DMA.

nports=num

Set the number of ports.

pci=index

The PCI index of the controller in the machine, where index is a value between 0 and the number of adapters.

pi=bitmap

Set the ports implemented bitmap. For example, pi=0x4 specifies port 2.

port=N,device

Specify options for device on port N.

priority=prio

Set the priority of the processing thread. The default is 21.

pwrdwn

Power down the device on exit.

rtime=timeout

Set the reset timeout, in seconds. The default is 40.

timeout=timeout

Set the I/O request timeout, in seconds. The default is 10.

vid=vid

The vendor ID of the controller.
Device-specific options:

chs

Use Cylinder-Head-Sector mode. The default is LBA.

geometry=heads:cyl:sect

Specify the drive geometry.

multiblk=blks

Set multiblock mode, using the given number of blocks per interrupt.

nobmstr

Don't use busmastering. Specify this option if you want to disable DMA.

nonremovable

Report the device as being nonremovable.

rahead=state

Enable or disable device read-ahead, where state is on or off.

smart

Enable SMART monitoring. If there are problems with the drive, the driver puts a message in the system log (see slog2info and slogger2).
Note: The message is logged only at startup.

There currently isn't a mechanism to retrieve SMART data.

verbose=level

Set the device verbosity level.

wcache=state

Enable or disable device write cache, where state is on or off.

blk options

The blk options control io-blk.so. If specified, they must follow the blk keyword.

Description:

The devb-ahci supports the Intel AHCI SATA controller ith the following device IDs:

ICH-6 82801FB_SATA 0x2651
ICH-6 82801FBM_SATA 0x2653
ICH-7 82801GB_SATA 0x27c1
ICH-7 82801GBM_SATA 0x27c5

Note: You need to enable AHCI mode in the BIOS.

Examples:

Detect all SATA controllers, and list all connected devices:

devb-ahci &

Detect all SATA controllers and use a typed memory region named dma (which the startup must have set up):

devb-ahci mem name=/ram/dma &

Files:

The devb-ahci driver causes io-blk.so to adopt various block special devices under /dev. These devices are normally named hdn, where n is the physical unit number of the device.

This driver could also require the following shared objects:

Binary	Required
cam-disk.so	For hard-disk access.
libcam.so	Always

Exit status:

The devb-ahci driver terminates only if an error occurs during startup, or if it has successfully forked itself upon startup because it hadn't been initially started in the background.

0: The devb-ahci driver wasn't started in the background and therefore forked itself. The original process terminated with a zero exit status, the forked process continued.
> 0: An error occurred during startup.

Caveats:

Unless overridden with the blk automount= option (see io-blk.so), devices are mounted as:

Device	Mountpoint	Filesystem type
/dev/hd0t177	/hd	`qnx6`
/dev/hd0t6	/dos	`dos`
/dev/hd0t11	/dos	`dos`

While there's no limit to the size of a disk or partition, the limit on I/O (i.e., the lseek(), read() and write() functions) depends on the type of filesystem mounted and on whether you use the 32- or 64-bit versions of these functions. This I/O limit has no effect on the partition size for mounted filesystems. The maximum number of blocks is 2³².

Known supported functions include:

chmod(), chown(), close(), closedir(), creat(), devctl(), dup(), dup2(), fcntl(), fpathconf(), fstat(), lseek(), mkdir(), mkfifo(), mknod(), open(), opendir(), pathconf(), read(), readdir(), readlink(), rewinddir(), rmdir(), stat(), symlink(), unlink() (not supported for directories), utime(), write()

Note that certain calls (such as pipe(), as well as read() and write() on FIFOs) may require the pipe manager.