Intel Extensible Firmware Interface - Manual (Page 770)

Extensible Firmware Interface Specification
18-10 12/01/02 Version 1.10
DEVICE_IO.Unmap()
Summary
Completes the Map() operation and releases any corresponding resources.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_IO_UNMAP) (
IN EFI_DEVICE_IO_INTERFACE *This,
IN VOID *Mapping
);
Parameters
This A pointer to the EFI_DEVICE_IO_INTERFACE instance. Type
EFI_DEVICE_IO_INTERFACE is defined in Section 18.2.
Mapping The mapping value returned from Map() .
Description
The Unmap() function completes the Map() operation and releases any corresponding resources.
If the operation was an EFIBusMasterWrite , the data is committed to the target system
memory. Any resources used for the mapping are freed.
Status Codes Returned
EFI_SUCCESS The range was unmapped.
EFI_DEVICE_ERROR The data was not committed to the target system memory.