iokit/IOKit/IORegistryEntry.h

230     @abstract Returns a pointer to the root instance of the registry.
231     @discussion This method provides an accessor to the root of the registry for the machine. The root may be passed to a registry iterator when iterating a plane, and contains properties that describe the available planes, and diagnostic information for IOKit. Keys for these properties are in IOKitKeys.h.
232     @result A pointer to the IORegistryEntry root instance. It should not be released by the caller. */
566     @abstract Counts the maximum number of entries between an entry and the registry root, in a plane.
567     @discussion This method counts the number of entries between and entry and the registry root, in a plane, for each parent of the entry and returns the maximum value.
569     @result The maximum number of entries between the entry and the root. Zero is returned if the entry is not attached in the plane. */
712     @discussion The path for a registry entry is copied to the caller's buffer. The path describes the entry's attachment in a particular plane, which must be specified. The path begins with the plane name followed by a colon, and then followed by '/' separated path components for each of the entries between the root and the registry entry. Each component is constructed with the getPathComponent method called in each entry. An alias may also exist for the entry, which are described as properties in a registry entry found at /aliases in the plane. If a property value interpreted as a path in a call to IORegistryEntry::fromPath yields the entry, then the property name is used as the entry's path.
739     @param fromEntry The lookup will proceed rooted at this entry if non-zero, otherwise it proceeds from the root of the plane.
852     IORegistryEntry 	  *	root;
862     @discussion This method creates an IORegistryIterator that is set up with options to iterate children or parents of a root entry, and to recurse automatically into entries as they are returned, or only when instructed. The iterator object keeps track of entries that have been recursed into previously to avoid loops.
863     @param start The root entry to begin the iteration at.
873     @abstract Create an iterator rooted at the registry root.
874     @discussion This method creates an IORegistryIterator that is set up with options to iterate children of the registry root entry, and to recurse automatically into entries as they are returned, or only when instructed. The iterator object keeps track of entries that have been recursed into previously to avoid loops.
891     @discussion This method returns the next child, or parent if the kIORegistryIterateParents option was used to create the iterator, of the current root entry. The object returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it.
898     @discussion If the iterator has a current entry, and the iterator has not already entered previously, enterEntry is called to recurse into it, ie. make it the new root, and the next child, or parent if the kIORegistryIterateParents option was used to create the iterator, at this new level of recursion is returned. If there is no current entry at this level of recursion, exitEntry is called and the process repeats, until the iteration returns to the entry the iterator was created with and zero is returned. The object returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it.
912     @discussion This method makes the current entry, ie. the last entry returned by getNextObject et al., the root in a new level of recursion. */