IDmaChannel::CopyFrom

The CopyFrom method copies sample data from the DMA channel's common buffer to the specified destination buffer.

NTSTATUS 
  CopyFrom(
    IN PVOID  Destination,
    IN PVOID  Source,
    IN ULONG  ByteCount
    );

Parameters

Destination

Pointer to the destination buffer

Source

Pointer to the source buffer, which is located in the DMA channel's common buffer.

ByteCount

Specifies the number of bytes to be copied.

Return Value

CopyFrom returns STATUS_SUCCESS if the call was successful. Otherwise, the method returns an appropriate error code.

Headers

Declared in portcls.h. Include portcls.h.

Comment

The Source and Destination pointers are both kernel-mode virtual addresses. The IDmaChannel::SystemAddress call returns the virtual address of a DMA channel's common buffer.

The Source parameter points to the beginning of the source buffer, which occupies ByteCount contiguous bytes in the DMA channel's common buffer.

The CopyFrom method can be called at any IRQL.

See Also

IDmaChannel::SystemAddress