Overview

Command structure superclass, created and freed only by IOATADevice objects populated by disk device drivers with command parameters then submitted for operation to their IOATADevice provider for execution.

IOATACommand is a virtual class, a concrete subclass contains the methods and fields needed by IOATAControllers. Subclasses may be specific to particular controller hardware. Disk device drivers will only have visibility to this interface and may not subclass this object. Disk device drivers should instead make use of the void* refcon field which the controllers will not touch

Functions

getActualTransfer

The byte count on the ending result, as best as can be determined by the controller. May be zero, but partial transfer may have occurred on error in some cases.

getBuffer

the IOMemoryDescriptor used in this transaction.

getCommandInUse

returns true if IOATAController is still in control of the command.

getCylHi

Taskfile access. Registers are named in accordance with ATA Standards conventions

getCylLo

Taskfile access. Registers are named in accordance with ATA Standards conventions

getDevice_Head

Taskfile access. Registers are named in accordance with ATA Standards conventions

getEndErrorReg

If the error bit was set in the status register, the value of the error register is returned at the end of a command.

getEndStatusReg

the value of the status register on the end of the command.

getErrorReg

Taskfile access. Registers are named in accordance with ATA Standards conventions

getResult

IOReturn value of the result of this command. ATA family errors are defined in IOATATypes.h

getSectorCount

Taskfile access. Registers are named in accordance with ATA Standards conventions

getSectorNumber

Taskfile access. Registers are named in accordance with ATA Standards conventions

getStatus

Taskfile access. Registers are named in accordance with ATA Standards conventions

setBuffer

set the IIOMemoryDescriptor for this transaction.

setByteCount

set the byte count for this transaction. Should agree with the device command and the memory descriptor in use.

setCallbackPtr

set the function pointer to call when this command completes.

setCommand

Taskfile access. Registers are named in accordance with ATA Standards conventions

setCylHi

Taskfile access. Registers are named in accordance with ATA Standards conventions

setCylLo

Taskfile access. Registers are named in accordance with ATA Standards conventions

setDevice_Head

Taskfile access. Registers are named in accordance with ATA Standards conventions

setFeatures

Taskfile access. Registers are named in accordance with ATA Standards conventions

setFlags

set the flags for this command, as defined in IOATATypes.

setLBA28

convenience method that sets the taskfile registers into a 28-bit LBA address, with unit selected and LBA bit set. return err if param out of range, return kIOSuccess (kATANoErr) = 0 on return if successful

setOpcode

command opcode as defined in IOATATypes.

setPacketCommand

ATAPI command packet max size is 16 bytes. Makes deep copy of data.

setPosition

used to set an offset into the memory descriptor for this transfer.

setRegMask

used when accessing registers or reading registers on an error result. Mask is defined in IOATATypes.h

setSectorCount

Taskfile access. Registers are named in accordance with ATA Standards conventions

setSectorNumber

Taskfile access. Registers are named in accordance with ATA Standards conventions

setTimeoutMS

how long to allow this command to complete, in milliseconds, once issued to the hardware. if the time period expires, this command will return with a timeout error.

setTransferChunkSize

set the size of transfer between intervening interrupts. necessary when doing PIO Read/Write Multiple, etc. so the controller knows when to expect an interrupt during multi-sector data transfers.

setUnit

set the unit number for this command.

zeroCommand

set to blank state, MUST call prior to re-use of this object

The byte count on the ending result, as best as can be determined by the controller. May be zero, but partial transfer may have occurred on error in some cases.

public

virtual IOByteCount getActualTransfer (
    void ); 

the IOMemoryDescriptor used in this transaction.

public

virtual IOMemoryDescriptor* getBuffer (
    void ); 

returns true if IOATAController is still in control of the command.

public

virtual bool getCommandInUse(
    void ); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual UInt8 getCylHi (
    void ); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual UInt8 getCylLo (
    void ); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual UInt8 getDevice_Head (
    void ); 

If the error bit was set in the status register, the value of the error register is returned at the end of a command.

public

virtual UInt8 getEndErrorReg(
    void ); 

the value of the status register on the end of the command.

public

virtual UInt8 getEndStatusReg (
    void); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual UInt8 getErrorReg (
    void ); 

IOReturn value of the result of this command. ATA family errors are defined in IOATATypes.h

public

virtual IOReturn getResult (
    void); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual UInt8 getSectorCount (
    void ); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual UInt8 getSectorNumber (
    void ); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual UInt8 getStatus (
    void ); 

set the IIOMemoryDescriptor for this transaction.

public

virtual void setBuffer (
    IOMemoryDescriptor *inDesc); 

set the byte count for this transaction. Should agree with the device command and the memory descriptor in use.

public

virtual void setByteCount (
    IOByteCount numBytes); 

set the function pointer to call when this command completes.

public

virtual void setCallbackPtr (
    IOATACompletionFunction *inCompletion); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual void setCommand (
    UInt8 in); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual void setCylHi(
    UInt8 in); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual void setCylLo (
    UInt8 in); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual void setDevice_Head(
    UInt8 in); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual void setFeatures(
    UInt8 in); 

set the flags for this command, as defined in IOATATypes.

public

virtual void setFlags(
    UInt32 inFlags); 

convenience method that sets the taskfile registers into a 28-bit LBA address, with unit selected and LBA bit set. return err if param out of range, return kIOSuccess (kATANoErr) = 0 on return if successful

public

virtual IOReturn setLBA28(
    UInt32 lba,
    ataUnitID inUnit); 

command opcode as defined in IOATATypes.

public

virtual void setOpcode(
    ataOpcode inCode); 

ATAPI command packet max size is 16 bytes. Makes deep copy of data.

public

virtual IOReturn setPacketCommand(
    UInt16 packetSizeBytes,
    UInt8 *command); 

used to set an offset into the memory descriptor for this transfer.

public

virtual void setPosition (
    IOByteCount fromPosition); 

used when accessing registers or reading registers on an error result. Mask is defined in IOATATypes.h

public

virtual void setRegMask(
    ataRegMask mask); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual void setSectorCount(
    UInt8 in); 

Taskfile access. Registers are named in accordance with ATA Standards conventions

public

virtual void setSectorNumber(
    UInt8 in); 

how long to allow this command to complete, in milliseconds, once issued to the hardware. if the time period expires, this command will return with a timeout error.

public

virtual void setTimeoutMS(
    UInt32 inMs); 

set the size of transfer between intervening interrupts. necessary when doing PIO Read/Write Multiple, etc. so the controller knows when to expect an interrupt during multi-sector data transfers.

public

virtual void setTransferChunkSize(
    IOByteCount chunk = kATADefaultSectorSize); 

set the unit number for this command.

public

virtual void setUnit(
    ataUnitID inUnit); 

set to blank state, MUST call prior to re-use of this object

public

virtual void zeroCommand(
    void); 

Structs and Unions

ExpansionData

protected

struct ExpansionData {
    IOExtendedLBA *extLBA;
}; 

Discussion

This structure will be used to expand the capablilties of the IOWorkLoop in the future.

Member Data

fExpansionData

refCon

for use by disk drivers, clients of IOATADevice only. IOATADevice and IOATAControllers shall not use this field in any manner.

refCon2

for use by disk drivers, clients of IOATADevice only. IOATADevice and IOATAControllers shall not use this field in any manner.

reserved

protected

ExpansionData *fExpansionData; 

Discussion

Reserved for future use. (Internal use only)

See Also

for use by disk drivers, clients of IOATADevice only. IOATADevice and IOATAControllers shall not use this field in any manner.

public

void* refCon; 

for use by disk drivers, clients of IOATADevice only. IOATADevice and IOATAControllers shall not use this field in any manner.

public

void* refCon2; 

protected

ExpansionData *fExpansionData; 

Discussion

Reserved for future use. (Internal use only)

See Also

Last Updated: 2010-07-29