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ATA(4)			 BSD Kernel Interfaces Manual			ATA(4)

     ata, ar, acd, ad, afd, ast	-- generic ATA/ATAPI disk controller driver

     For ISA based ATA/ATAPI support:
     device isa
     device ata

     In	/boot/device.hints:"isa"

     For PC98 based ATA/ATAPI support:
     device isa
     device ata

     In	/boot/device.hints:"isa"

     For PCI based ATA/ATAPI support:
     device pci
     device ata

     To	support	ATA compliant disk drives:
     device atadisk

     To	support	ATA software RAID's:
     device ataraid

     To	support	ATAPI CDROM, DVD and CD/DVD burner drives:
     device atapicd

     To	support	ATAPI floppy drives:
     device atapifd

     To	support	ATAPI tape drives:
     device atapist

     The following tunables are	settable from the loader:

     set to 1 for DMA access, 0	for PIO	(default is DMA).

     set to 1 for DMA access, 0	for PIO	(default is DMA).

     set to 1 to enable	Write Caching, 0 to disable (default is	enabled).
     WARNING: can cause	data loss on power failures.

     The ata driver provides access to ATA (IDE) and SerialATA disk drives,
     ATAPI CDROM/DVD drives, ZIP/LS120 ATAPI drives and	ATAPI tape drives con-
     nected to controllers according to	the ATA/ATAPI standards.

     The currently supported ATA/SATA controller chips are:

     Acard:	     ATP850P, ATP860A, ATP860R,	ATP865A, ATP865R.
     ALI:	     M5229, M5281, M5287, M5289.
     AMD:	     AMD756, AMD766, AMD768, AMD8111.
     ATI:	     IXP200, IXP300, IXP400.
     CMD:	     CMD646, CMD646U2, CMD648, CMD649.
     Cypress:	     Cypress 82C693.
     Cyrix:	     Cyrix 5530.
     HighPoint:	     HPT302, HPT366, HPT368, HPT370, HPT371, HPT372, HPT372N,
     Intel:	     6300ESB, 31244, PIIX, PIIX3, PIIX4, ICH, ICH0, ICH2,
		     ICH3, ICH4, ICH5, ICH6, ICH7.
     ITE:	     IT8211F, IT8212F.
     National:	     SC1100.
     nVidia:	     nForce, nForce2, nForce2 MCP, nForce3, nForce3 MCP,
		     nForce3 Pro, nForce4.
     Promise:	     PDC20246, PDC20262, PDC20263, PDC20265, PDC20267,
		     PDC20268, PDC20269, PDC20270, PDC20271, PDC20275,
		     PDC20276, PDC20277, PDC20318, PDC20319, PDC20371,
		     PDC20375, PDC20376, PDC20377, PDC20378, PDC20379,
		     PDC20571, PDC20575, PDC20579, PDC20580, PDC20617,
		     PDC20618, PDC20619, PDC20620, PDC20621, PDC20622,
		     PDC40518, PDC40519, PDC40718, PDC40719.
     ServerWorks:    ROSB4, CSB5, CSB6.
     Silicon Image:  SiI0680, SiI3112, SiI3114,	SiI3512.
     SiS:	     SIS180, SIS181, SIS182, SIS5513, SIS530, SIS540, SIS550,
		     SIS620, SIS630, SIS630S, SIS633, SIS635, SIS730, SIS733,
		     SIS735, SIS745, SIS961, SIS962, SIS963, SIS964, SIS965.
     VIA:	     VT6410, VT6420, VT6421, VT82C586, VT82C586B, VT82C596,
		     VT82C596B,	VT82C686, VT82C686A, VT82C686B,	VT8231,
		     VT8233, VT8233A, VT8233C, VT8235, VT8237.

     Unknown ATA chipsets are supported	in PIO modes, and if the standard bus-
     master DMA	registers are present and contain valid	setup, DMA is also en-
     abled, although the max mode is limited to	UDMA33,	as it is not known
     what the chipset can do and how to	program	it.

     The ata driver can	change the transfer mode and various other parameters
     when the system is	up and running.	 See atacontrol(8).

     The ata driver sets the maximum transfer mode supported by	the hardware
     as	default.  However the ata driver sometimes warns: "DMA limited to
     UDMA33, non-ATA66 cable or	device".  This means that the ata driver has
     detected that the required	80 conductor cable is not present or could not
     be	detected properly, or that one of the devices on the channel only ac-
     cepts up to UDMA2/ATA33.

     Unknown ATAPI devices are initialized to DMA mode if the hw.ata.atapi_dma
     tunable is	set to 1 and they support at least UDMA33 transfers.  Other-
     wise they are set to PIO mode because severe DMA problems are common even
     if	the device capabilities	indicate support.  You can always try to set
     DMA mode on an ATAPI device using atacontrol(8), but be aware that	your
     hardware might not	support	it and can potentially hang the	entire system
     causing data loss.

     /dev/ad*		     ATA disk device nodes
     /dev/ar*		     ATA RAID device nodes
     /dev/acd*		     ATAPI CD-ROM device nodes
     /dev/afd*		     ATAPI floppy drive	device nodes
     /dev/ast*		     ATAPI tape	drive device nodes
     /sys/i386/conf/GENERIC  sample generic kernel config file for ata based

     Please remember that in order to use UDMA4/ATA66 and above	modes you must
     use 80 conductor cables.  Please assure that ribbon cables	are no longer
     than 45cm.	 In case of rounded ATA	cables,	the length depends on the
     quality of	the cables.  SATA cables can be	up to 1m long according	to the

     Static device numbering (enabled with the ATA_STATIC_ID kernel option)
     reserves a	number for each	possibly connected disk, even when not
     present.  This is useful in hotswap scenarios where disks should always
     show up as	the same numbered device, and not depend on attach order.

     ataraid(4), atacontrol(8),	burncd(8)

     The ata driver first appeared in FreeBSD 4.0.

     Soren Schmidt <>.

BSD			       October 13, 2005				   BSD


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