cloneCommand

Creates a new command based on the specification of the current one.

Declaration

virtual IODMACommand *cloneCommand(
 void *refCon = 0); 

Return Value

Returns a new memory cursor if successfully created and initialised, 0 otherwise.

Overview

Factory function to create and initialise an IODMACommand in one operation. The current command's specification will be duplicated in the new object, but however none of its state will be duplicated. This means that it is safe to clone a command even if it is currently active and running, however you must be certain that the command to be duplicated does have a valid reference for the duration.

See Also

Miscellaneous

- clearMemoryDescriptor

Clears the DMACommand's current memory descriptor

- complete

Complete processing of DMA mappings after an I/O transfer is finished.

- gen32IOVMSegments

Helper function for a type checked call to genIOVMSegments(qv), for use with an IODMACommand set up with the output function kIODMACommandOutputHost32, kIODMACommandOutputBig32, or kIODMACommandOutputLittle32. If the output function of the IODMACommand is not a 32 bit function, results will be incorrect.

- gen64IOVMSegments

Helper function for a type checked call to genIOVMSegments(qv), for use with an IODMACommand set up with the output function kIODMACommandOutputHost64, kIODMACommandOutputBig64, or kIODMACommandOutputLittle64. If the output function of the IODMACommand is not a 64 bit function, results will be incorrect.

- genIOVMSegments

Generates a physical scatter/gather for the current DMA command

- getMemoryDescriptor

Get the current memory descriptor

- getPreparedOffsetAndLength

Returns the offset and length into the target IOMemoryDescriptor of a prepared IODDMACommand.

- initWithSpecification

Primary initializer for the IODMACommand class.

- OutputBig32

Output big-endian Segment32 output segment function.

- OutputBig64

Output big-endian Segment64 output segment function.

- OutputHost32

Output host natural Segment32 output segment function.

- OutputHost64

Output host natural Segment64 output segment function.

- OutputLittle32

Output little-endian Segment32 output segment function.

- OutputLittle64

Output little-endian Segment64 output segment function.

- prepare

Prepare the memory for an I/O transfer.

- prepareWithSpecification

Prepare the memory for an I/O transfer with a new specification.

- readBytes

Copy data from the IODMACommand's buffer to the specified buffer.

- setMemoryDescriptor

Sets and resets the DMACommand's current memory descriptor

- synchronize

Bring IOMemoryDescriptor and IODMACommand buffers into sync.

- weakWithSpecification

Creates and initialises an IODMACommand in one operation if this version of the operating system supports it.

- withSpecification

Creates and initializes an IODMACommand in one operation.

- writeBytes

Copy data to the IODMACommand's buffer from the specified buffer.