iokit/IOKit/IOMemoryDescriptor.h

150     @discussion The IOMemoryDescriptor object represents a buffer or range of memory, specified as one or more physical or virtual address ranges. It contains methods to return the memory's physically contiguous segments (fragments), for use with the IOMemoryCursor, and methods to map the memory into any address space with caching and placed mapping options. */
222     @discussion This method performs some operation on a range of the memory descriptor's memory. When a memory descriptor's memory is not mapped, it should be more efficient to use this method than mapping the memory to perform the operation virtually.
541     @discussion This is the general purpose method to map all or part of the memory described by a memory descriptor into a task at any available address, or at a fixed address if possible. Caching & read-only options may be set for the mapping. The mapping is represented as a returned reference to a IOMemoryMap object, which may be shared if the mapping is compatible with an existing mapping of the IOMemoryDescriptor. The IOMemoryMap object returned should be released only when the caller has finished accessing the mapping, as freeing the object destroys the mapping.
542     @param intoTask Sets the target task for the mapping. Pass kernel_task for the kernel address space.
543     @param atAddress If a placed mapping is requested, atAddress specifies its address, and the kIOMapAnywhere should not be set. Otherwise, atAddress is ignored.
545 	kIOMapAnywhere should be passed if the mapping can be created anywhere. If not set, the atAddress parameter sets the location of the mapping, if it is available in the target map.<br>
549 	kIOMapReference will only succeed if the mapping already exists, and the IOMemoryMap object is just an extra reference, ie. no new mapping will be created.<br>
550 	kIOMapUnique allows a special kind of mapping to be created that may be used with the IOMemoryMap::redirect() API. These mappings will not be shared as is the default - there will always be a unique mapping created for the caller, not an existing mapping with an extra reference.<br>
551     @param offset Is a beginning offset into the IOMemoryDescriptor's memory where the mapping starts. Zero is the default to map all the memory.
552     @param length Is the length of the mapping requested for a subset of the IOMemoryDescriptor. Zero is the default to map all the memory.
553     @result A reference to an IOMemoryMap object representing the mapping, which can supply the virtual address of the mapping and other information. The mapping may be shared with multiple callers - multiple maps are avoided if a compatible one exists. The IOMemoryMap object returned should be released only when the caller has finished accessing the mapping, as freeing the object destroys the mapping. The IOMemoryMap instance also retains the IOMemoryDescriptor it maps while it exists. */
581     @abstract Establishes an already existing mapping.
582     @discussion This method tells the IOMemoryDescriptor about a mapping that exists, but was created elsewhere. It allows later callers of the map method to share this externally created mapping. The IOMemoryMap object returned is created to represent it. This method is not commonly needed.
583     @param task Address space in which the mapping exists.
584     @param mapAddress Virtual address of the mapping.
585     @param options Caching and read-only attributes of the mapping.
586     @result A IOMemoryMap object created to represent the mapping. */
618 	IOMemoryMap *		mapping );
621 	IOMemoryMap *		mapping );
639     @abstract A class defining common methods for describing a memory mapping.
640     @discussion The IOMemoryMap object represents a mapped range of memory, described by a IOMemoryDescriptor. The mapping may be in the kernel or a non-kernel task and has processor cache mode attributes. IOMemoryMap instances are created by IOMemoryDescriptor when it creates mappings in its map method, and returned to the caller. */
667     @abstract Accessor to the virtual address of the first byte in the mapping.
668     @discussion This method returns the virtual address of the first byte in the mapping. Since the IOVirtualAddress is only 32bit in 32bit kernels, the getAddress() method should be used for compatibility with 64bit task mappings.
674     @abstract Break a mapping into its physically contiguous segments.
675     @discussion This method returns the physical address of the byte at the given offset into the mapping, and optionally the length of the physically contiguous segment from that offset. It functions similarly to IOMemoryDescriptor::getPhysicalSegment.
676     @param offset A byte offset into the mapping whose physical address to return.
678     @result A physical address, or zero if the offset is beyond the length of the mapping. */
690     @abstract Return the physical address of the first byte in the mapping.
691     @discussion This method returns the physical address of the  first byte in the mapping. It is most useful on mappings known to be physically contiguous.
697     @abstract Accessor to the length of the mapping.
698     @discussion This method returns the length of the mapping.
704     @abstract Accessor to the task of the mapping.
705     @discussion This method returns the mach task the mapping exists in.
711     @abstract Accessor to the IOMemoryDescriptor the mapping was created from.
712     @discussion This method returns the IOMemoryDescriptor the mapping was created from.
718     @abstract Accessor to the options the mapping was created with.
719     @discussion This method returns the options to IOMemoryDescriptor::map the mapping was created with.
720     @result Options for the mapping, including cache settings. */
726     @discussion IOMemoryMap instances will unmap themselves upon free, ie. when the last client with a reference calls release. This method forces the IOMemoryMap to destroy the mapping it represents, regardless of the number of clients. It is not generally used.
736     @param newBackingMemory The IOMemoryDescriptor that represents the physical memory that is to be now mapped in the virtual range the IOMemoryMap represents. If newBackingMemory is NULL, any access to the mapping will hang (in vm_fault()) until access has been restored by a new call to redirect() with non-NULL newBackingMemory argument.
738     @param offset As with IOMemoryDescriptor::map(), a beginning offset into the IOMemoryDescriptor's memory where the mapping starts. Zero is the default.
754     @abstract Accessor to the virtual address of the first byte in the mapping.
755     @discussion This method returns the virtual address of the first byte in the mapping.
758     @abstract Accessor to the length of the mapping.
759     @discussion This method returns the length of the mapping.
765     @abstract Accessor to the virtual address of the first byte in the mapping.
766     @discussion This method returns the virtual address of the first byte in the mapping.
769     @abstract Accessor to the length of the mapping.
770     @discussion This method returns the length of the mapping.