Contents

CreateIOBuffer

Allocates a buffer for use during I/O operations.

Declaration

virtual kern_return_t CreateIOBuffer(IOOptionBits options, uint64_t capacity, IOBufferMemoryDescriptor **buffer);

Parameters

  • options:

    The direction of I/O transfer for the buffer. For a list of possible values, see Memory Buffer Options.

  • capacity:

    The size of the buffer to allocate in bytes.

  • buffer:

    A pointer to a variable. On success, this variable contains a pointer to a memory descriptor. It’s your responsibility to release this memory descriptor when you finish using it. If an error occurs, the method returns NULL instead.

Return Value

kIOReturnSuccess on success, or another value if an error occurs. See Error Codes.

Discussion

This method allocates an IOBufferMemoryDescriptor optimized for use by the underlying controller hardware. A buffer allocated by this method isn’t bounced to perform DMA operations.