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     ata — generic ATA/SATA controller driver


     To compile this driver into the kernel, place the following lines in your kernel
     configuration file:

           device scbus
           device ata

     Alternatively, to load the driver as set of modules at boot time, place some of the
     following lines in loader.conf(5):




     The first line is for the common hardware independent code, and is a prerequisite for the
     other modules.  The next three lines are generic bus-specific drivers.  The rest are vendor-
     specific PCI drivers.

     The following tunables are settable from the loader(8):

     set to 0 to disable the 80pin cable check (the default is 1, check the cable).

     set to 1 to allow Message Signalled Interrupts (MSI) to be used by the specified PCI ATA
     controller, if supported.

     limits the initial ATA mode for the specified device on the specified channel.

     limits the initial ATA mode for every device on the specified channel.

     controls SATA interface Power Management for the specified channel, allowing some power
     savings at the cost of additional command latency.  Possible values:

           0     Interface Power Management is disabled.  This is the default value.
           1     The device is allowed to initiate a PM state change; the host is passive.

     limits the initial SATA revision (speed) for the specified device on the specified channel.
     Values 1, 2 and 3 are respectively 1.5, 3 and 6Gbps.

     Same, but for every device on the specified channel.


     The ata driver gives the CAM(4) subsystem access to the ATA (IDE) and SATA ports of many
     generic controllers.  Depending on the controller, each PATA (IDE) port or each one or two
     SATA ports are represented to CAM as a separate bus with one or two targets.  Most of the
     bus-management details are handled by the ATA/SATA-specific transport of CAM.  Connected ATA
     disks are handled by the ATA protocol disk peripheral driver ada(4).  ATAPI devices are
     handled by the SCSI protocol peripheral drivers cd(4), da(4), sa(4), etc.

     This driver supports ATA, and for the most of controllers, ATAPI devices.  Command queuing
     and SATA port multipliers are not supported.  Device hot-plug and SATA interface power
     management is supported only on some controllers.

     The ata driver can change the transfer mode when the system is up and running.  See the
     negotiate subcommand of camcontrol(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
     accepts up to UDMA2/ATA33.  The hw.ata.ata_dma_check_80pin tunable can be set to 0 to
     disable this check.


     The currently supported ATA/SATA controller chips are:

     Acard:          ATP850P, ATP860A, ATP860R, ATP865A, ATP865R.
     ALI:            M5228, M5229, M5281, M5283, M5287, M5288, M5289.
     AMD:            AMD756, AMD766, AMD768, AMD8111, CS5536.
     ATI:            IXP200, IXP300, IXP400, IXP600, IXP700, IXP800.
     CMD:            CMD646, CMD646U2, CMD648, CMD649.
     Cypress:        Cypress 82C693.
     Cyrix:          Cyrix 5530.
     HighPoint:      HPT302, HPT366, HPT368, HPT370, HPT371, HPT372, HPT372N, HPT374.
     Intel:          6300ESB, 31244, PIIX, PIIX3, PIIX4, ESB2, ICH, ICH0, ICH2, ICH3, ICH4, ICH5,
                     ICH6, ICH7, ICH8, ICH9, ICH10, SCH, PCH.
     ITE:            IT8211F, IT8212F, IT8213F.
     JMicron:        JMB360, JMB361, JMB363, JMB365, JMB366, JMB368.
     Marvell         88SE6101, 88SE6102, 88SE6111, 88SE6121, 88SE6141, 88SE6145.
     National:       SC1100.
     NetCell:        NC3000, NC5000.
     nVidia:         nForce, nForce2, nForce2 MCP, nForce3, nForce3 MCP, nForce3 Pro, nForce4,
                     MCP51, MCP55, MCP61, MCP65, MCP67, MCP73, MCP77, MCP79, MCP89.
     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:    HT1000, ROSB4, CSB5, CSB6, K2, Frodo4, Frodo8.
     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,
                     VT8237A, VT8237S, VT8251, CX700, VX800, VX855, VX900.

     Some of above chips can be configured for AHCI mode.  In such case they are supported by
     ahci(4) driver instead.

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


     The PC Card attachment of this driver is scheduled for removal prior to the release of
     FreeBSD 13.0


     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 specification.  External SATA cables can be 2m long and more, but not all
     controllers work well on long cables, especially at high speeds.


     ada(4), ahci(4), cam(4), cd(4), mvs(4), siis(4), camcontrol(8)


     The ata driver first appeared in FreeBSD 4.0.  It was turned into a CAM(4) interface module
     in FreeBSD 9.0.


     Alexander Motin <>
     Søren Schmidt <>