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IOKitLib.h

Include Path:	<IOKit/IOKitLib.h>
Path:	/System/Library/Frameworks/IOKit.framework/Versions/A/Headers/IOKitLib.h
Includes:	<sys/cdefs.h> <sys/types.h> <mach/mach_types.h> <mach/mach_init.h> <CoreFoundation/CFBase.h> <CoreFoundation/CFDictionary.h> <CoreFoundation/CFRunLoop.h> <IOKit/IOTypes.h> <IOKit/IOKitKeys.h> <IOKit/OSMessageNotification.h> <AvailabilityMacros.h>

Overview

IOKitLib implements non-kernel task access to common I/O Kit objects - IORegistryEntry, IOService, IOIterator etc. These functions are generic - families may provide API that is more specific.

IOKitLib represents I/O Kit objects outside the kernel with the types io_object_t, io_registry_entry_t, io_service_t, and io_connect_t.

Function names usually begin with the type of object they are compatible with, e.g. IOObjectRelease can be used with any io_object_t.

Inside the kernel, the C++ class hierarchy allows the subclasses of each object type to receive the same requests from user level clients. For example, in the kernel, IOService is a subclass of IORegistryEntry, which means any of the IORegistryEntryXXX functions in IOKitLib may be passed a variable of either type io_service_t or type io_registry_t.

There are functions available to introspect the class of the kernel object which any io_object_t et al. represents. I/O Kit objects returned by all functions should be released with IOObjectRelease.

Functions

CFStringRef IOObjectCopyBundleIdentifierForClass: Returns the bundle identifier of the given class.
CFStringRef IOObjectCopyClass: Returns the class name of an I/O Kit object.
CFStringRef IOObjectCopySuperclassForClass: Returns the superclass name of the given class.
IOBSDNameMatching: Creates a matching dictionary that specifies an IOService match based on BSD device name.
IOConnectAddClient: Informs a connection of a second connection.
IOConnectAddRef: Adds a reference to the connect handle.
IOConnectGetService: Returns the IOService object a connect handle was opened on.
IOConnectMapMemory: Maps hardware or shared memory into the caller's task.
IOConnectRelease: Removes a reference to the connect handle.
IOConnectSetCFProperties: Sets CF container-based properties on a connection.
IOConnectSetCFProperty: Sets a CF container-based property on a connection.
IOConnectSetNotificationPort: Sets a port to receive family specific notifications.
IOConnectUnmapMemory: Removes a mapping made with IOConnectMapMemory.
IOCreateReceivePort: Creates and returns a Mach port suitable for receiving I/O Kit messages of the specified type.
IODispatchCalloutFromMessage: Dispatches callback notifications from a Mach message.
IOIteratorIsValid: Checks an iterator is still valid.
IOIteratorNext: Returns the next object in an iteration.
IOIteratorReset: Resets an iteration back to the beginning.
IOKitGetBusyState: Returns the busyState of all IOService objects.
IOKitWaitQuiet: Waits for the busyState of all IOService objects to be zero.
IOMasterPort: Returns the Mach port used to initiate communication with the I/O Kit.
IONotificationPortCreate: Creates and returns a notification object for receiving I/O Kit notifications of new devices or state changes.
IONotificationPortDestroy: Destroys a notification object created with IONotificationPortCreate.
IONotificationPortGetMachPort: Returns a Mach port to be used to listen for notifications.
IONotificationPortGetRunLoopSource: Returns a CFRunLoopSource to be used to listen for notifications.
IOObjectConformsTo: Performs an OSDynamicCast operation on an I/O Kit object.
IOObjectCopyBundleIdentifierForClass IOObjectCopyBundleIdentifierForClass: Returns the bundle identifier of the given class.
IOObjectCopyClass IOObjectCopyClass: Returns the class name of an I/O Kit object.
IOObjectCopySuperclassForClass IOObjectCopySuperclassForClass: Returns the superclass name of the given class.
IOObjectGetClass: Returns the class name of an I/O Kit object.
IOObjectGetRetainCount: Returns kernel retain count of an I/O Kit object.
IOObjectIsEqualTo: Checks two object handles to see if they represent the same kernel object.
IOObjectRelease: Releases an object handle previously returned by IOKitLib.
IOObjectRetain: Retains an object handle previously returned by IOKitLib.
IOOpenFirmwarePathMatching: Creates a matching dictionary that specifies an IOService match based on an OpenFirmware device path.
IORegistryCreateIterator: Creates an iterator rooted at the I/O Registry root.
IORegistryEntryCreateCFProperties: Creates a CFDictionary representation of a registry entry's property table.
IORegistryEntryCreateCFProperty: Creates a CF representation of a registry entry's property.
IORegistryEntryCreateIterator: Creates an iterator rooted at a given registry entry.
IORegistryEntryFromPath: Looks up a registry entry by path.
IORegistryEntryGetChildEntry: Returns the first child of a registry entry in a plane.
IORegistryEntryGetChildIterator: Returns an iterator over a registry entry's child entries in a plane.
IORegistryEntryGetLocationInPlane: Returns a C string location assigned to a registry entry, in a specified plane.
IORegistryEntryGetName: Returns a C string name assigned to a registry entry.
IORegistryEntryGetNameInPlane: Returns a C string name assigned to a registry entry, in a specified plane.
IORegistryEntryGetParentEntry: Returns the first parent of a registry entry in a plane.
IORegistryEntryGetParentIterator: Returns an iterator over a registry entry's parent entries in a plane.
IORegistryEntryGetPath: Creates a path for a registry entry.
IORegistryEntryInPlane: Determines if the registry entry is attached in a plane.
IORegistryEntrySearchCFProperty: Creates a CF representation of a registry entry's property.
IORegistryEntrySetCFProperties: Sets CF container-based properties in a registry entry.
IORegistryEntrySetCFProperty: Sets a CF container-based property in a registry entry.
IORegistryGetRootEntry: Returns a handle to the I/O Registry root.
IORegistryIteratorEnterEntry: Recurses into the current entry in the registry iteration.
IORegistryIteratorExitEntry: Exits a level of recursion, restoring the current entry.
IOServiceAddInterestNotification: Register for notification of state changes in an IOService object.
IOServiceAddMatchingNotification: Looks up registered IOService objects that match a matching dictionary, and install a notification request of new IOService objects that match.
IOServiceClose: Closes a connection to an IOService object and destroys the connect handle.
IOServiceGetBusyState: Returns the busyState of an IOService object.
IOServiceGetMatchingService: Look up a registered IOService object that matches a matching dictionary.
IOServiceGetMatchingServices: Look up registered IOService objects that match a matching dictionary.
IOServiceMatching: Creates a matching dictionary that specifies an IOService class match.
IOServiceMatchPropertyTable: Match an IOService objects with matching dictionary.
IOServiceNameMatching: Creates a matching dictionary that specifies an IOService name match.
IOServiceOFPathToBSDName: Looks up an IOService from its OpenFirmware device path and returns its BSD device name, if available.
IOServiceOpen: Requests the creation of a connection to an IOService object.
IOServiceRequestProbe: Requests a rescan of a bus for device changes.
IOServiceWaitQuiet: Waits for an IOService object's busyState to be zero.

CFStringRef IOObjectCopyBundleIdentifierForClass

Returns the bundle identifier of the given class.

CFStringRef IOObjectCopyBundleIdentifierForClass(
    CFStringRef classname);

Parameters

classname: The name of the class as a CFString.

Return Value

The resulting CFStringRef. This should be released by the caller. If a valid class name is not passed in, then NULL is returned.

Discussion

This function uses the OSMetaClass system in the kernel to derive the name of the kmod, which is the same as the bundle identifier.

CFStringRef IOObjectCopyClass

Returns the class name of an I/O Kit object.

CFStringRef IOObjectCopyClass(
    io_object_t object) ;

Parameters

object: The I/O Kit object.

Return Value

The resulting CFStringRef. This should be released by the caller. If a valid object is not passed in, then NULL is returned.

Discussion

This function does the same thing as IOObjectGetClass, but returns the result as a CFStringRef.

Availability: Introduced in Mac OS X v10.4.

CFStringRef IOObjectCopySuperclassForClass

Returns the superclass name of the given class.

CFStringRef IOObjectCopySuperclassForClass(
    CFStringRef classname);

Parameters

classname: The name of the class as a CFString.

Return Value

The resulting CFStringRef. This should be released by the caller. If there is no superclass, or a valid class name is not passed in, then NULL is returned.

Discussion

This function uses the OSMetaClass system in the kernel to derive the name of the superclass of the class.

IOBSDNameMatching

Creates a matching dictionary that specifies an IOService match based on BSD device name.

CFMutableDictionaryRef IOBSDNameMatching( 
    mach_port_t masterPort, 
    uint32_t options, 
    const char *bsdName );

Parameters

masterPort: The master port obtained from IOMasterPort. Pass kIOMasterPortDefault to look up the default master port.
options: No options are currently defined.
bsdName: The BSD name, as a const char pointer.

Return Value

The matching dictionary created, is returned on success, or zero on failure. The dictionary is commonly passed to IOServiceGetMatchingServices or IOServiceAddMatchingNotification which will consume a reference, otherwise it should be released with CFRelease by the caller.

Discussion

IOService objects that represent BSD devices have an associated BSD name. This function creates a matching dictionary that will match IOService objects with a given BSD name.

IOConnectAddClient

Informs a connection of a second connection.

kern_return_t IOConnectAddClient( 
    io_connect_t connect, 
    io_connect_t client );

Parameters

connect: The connect handle created by IOServiceOpen.
client: Another connect handle created by IOServiceOpen.

Return Value

A kern_return_t error code returned by the family.

Discussion

This is a generic method to inform a family connection of a second connection, and is rarely used.

IOConnectAddRef

Adds a reference to the connect handle.

kern_return_t IOConnectAddRef( 
    io_connect_t connect );

Parameters

connect: The connect handle created by IOServiceOpen.

Return Value

A kern_return_t error code.

IOConnectGetService

Returns the IOService object a connect handle was opened on.

kern_return_t IOConnectGetService( 
    io_connect_t connect, 
    io_service_t *service );

Parameters

connect: The connect handle created by IOServiceOpen.
service: On success, the service handle the connection was opened on, which should be released with IOObjectRelease.

Return Value

A kern_return_t error code.

Discussion

Finds and returns the service object a connection was opened on.

IOConnectMapMemory

Maps hardware or shared memory into the caller's task.

kern_return_t IOConnectMapMemory( 
    io_connect_t connect, 
    uint32_t memoryType, 
    task_port_t intoTask, 
    vm_address_t *atAddress, 
    vm_size_t *ofSize, 
    IOOptionBits options );

Parameters

connect: The connect handle created by IOServiceOpen.
memoryType: What is being requested to be mapped, family defined and not interpreted by I/O Kit. The family may support physical hardware or shared memory mappings.
intoTask: The task port for the task in which to create the mapping (note that this may be different from the task that opened the connection). Pass mach_task_self() to refer to the process calling this function. Note that in Mac OS X, each process is based on a Mach task and one or more Mach threads. For more information on the composition of a Mach task and its relationship with Mach threads, see "Tasks and Threads".
atAddress: An in/out parameter - if the kIOMapAnywhere option is not set, the caller should pass the address where it requests the mapping be created, otherwise nothing needs to be set on input. The address of the mapping created is passed back on success.
ofSize: The size of the mapping created is passed back on success.

Return Value

A kern_return_t error code.

Discussion

This is a generic method to create a mapping in the caller's task. The family will interpret the memoryType parameter to determine what sort of mapping is being requested. Cache modes and placed mappings may be requested by the caller.

IOConnectRelease

Removes a reference to the connect handle.

kern_return_t IOConnectRelease( 
    io_connect_t connect );

Parameters

connect: The connect handle created by IOServiceOpen.

Return Value

A kern_return_t error code.

Discussion

If the last reference is removed an implicit IOServiceClose is performed.

IOConnectSetCFProperties

Sets CF container-based properties on a connection.

kern_return_t IOConnectSetCFProperties( 
    io_connect_t connect, 
    CFTypeRef properties );

Parameters

connect: The connect handle created by IOServiceOpen.
properties: A CF container - commonly a CFDictionary but this is not enforced. The container should consist of objects which are understood by the I/O Kit - these are currently : CFDictionary, CFArray, CFSet, CFString, CFData, CFNumber, CFBoolean, and are passed in the kernel as the corresponding OSDictionary, OSArray, etc. objects.

Return Value

A kern_return_t error code returned by the family.

Discussion

This is a generic method to pass a CF container of properties to the connection. The properties are interpreted by the family and commonly represent configuration settings, but may be interpreted as anything.

IOConnectSetCFProperty

Sets a CF container-based property on a connection.

kern_return_t IOConnectSetCFProperty( 
    io_connect_t connect, 
    CFStringRef propertyName, 
    CFTypeRef property );

Parameters

connect: The connect handle created by IOServiceOpen.
propertyName: The name of the property as a CFString.
property: A CF container - should consist of objects which are understood by the I/O Kit - these are currently : CFDictionary, CFArray, CFSet, CFString, CFData, CFNumber, CFBoolean, and are passed in the kernel as the corresponding OSDictionary etc. objects.

Return Value

A kern_return_t error code returned by the object.

Discussion

This is a generic method to pass a CF property to the connection. The property is interpreted by the family and commonly represents configuration settings, but may be interpreted as anything.

IOConnectSetNotificationPort

Sets a port to receive family specific notifications.

kern_return_t IOConnectSetNotificationPort( 
    io_connect_t connect, 
    uint32_t type, 
    mach_port_t port, 
    uintptr_t reference );

Parameters

connect: The connect handle created by IOServiceOpen.
type: The type of notification requested, family defined and not interpreted by the I/O Kit.
port: The port to which to send notifications.
reference: Some families may support passing a reference parameter for the caller's use with the notification.

Return Value

A kern_return_t error code.

Discussion

This is a generic method to pass a Mach port send right to be be used by family specific notifications.

IOConnectUnmapMemory

Removes a mapping made with IOConnectMapMemory.

kern_return_t IOConnectUnmapMemory( 
    io_connect_t connect, 
    uint32_t memoryType, 
    task_port_t fromTask, 
    vm_address_t atAddress );

Parameters

connect: The connect handle created by IOServiceOpen.
memoryType: The memory type originally requested in IOConnectMapMemory.
intoTask: The task port for the task from which to remove the mapping (note that this may be different from the task that opened the connection). Pass mach_task_self() to refer to the process calling this function. Note in Mac OS X, each process is based on a Mach task and one or more Mach threads. For more information on the composition of a Mach task and its relationship with Mach threads, see "Tasks and Threads".
atAddress: The address of the mapping to be removed.

Return Value

A kern_return_t error code.

Discussion

This is a generic method to remove a mapping in the caller's task.

IOCreateReceivePort

Creates and returns a Mach port suitable for receiving I/O Kit messages of the specified type.

kern_return_t IOCreateReceivePort(
    uint32_t msgType,
    mach_port_t *recvPort );

Parameters

msgType: Type of message to be sent to this port (kOSNotificationMessageID or kOSAsyncCompleteMessageID).
recvPort: The created port is returned.

Return Value

A kern_return_t error code.

Discussion

In the future, the I/O Kit may use specialized messages and ports instead of the standard ports created by mach_port_allocate(). Use this function instead of mach_port_allocate() to ensure compatibility with future revisions of the I/O Kit.

IODispatchCalloutFromMessage

Dispatches callback notifications from a Mach message.

void IODispatchCalloutFromMessage( 
    void *unused, 
    mach_msg_header_t *msg, 
    void *reference );

Parameters

unused: Not used, set to zero.
msg: A pointer to the message received.
reference: Pass the IONotificationPortRef for the object.

Discussion

A notification object may deliver notifications to a Mach messaging client, which should call this function to generate the callbacks associated with the notifications arriving on the port.

IOIteratorIsValid

Checks an iterator is still valid.

boolean_t IOIteratorIsValid( 
    io_iterator_t iterator );

Parameters

iterator: An I/O Kit iterator handle.

Return Value

True if the iterator handle is valid, otherwise false is returned.

Discussion

Some iterators will be made invalid if changes are made to the structure they are iterating over. This function checks the iterator is still valid and should be called when IOIteratorNext returns zero. An invalid iterator can be reset and the iteration restarted.

IOIteratorNext

Returns the next object in an iteration.

io_object_t IOIteratorNext( 
    io_iterator_t iterator );

Parameters

iterator: An I/O Kit iterator handle.

Return Value

If the iterator handle is valid, the next element in the iteration is returned, otherwise zero is returned. The element should be released by the caller when it is finished.

Discussion

This function returns the next object in an iteration, or zero if no more remain or the iterator is invalid.

IOIteratorReset

Resets an iteration back to the beginning.

void IOIteratorReset( 
    io_iterator_t iterator );

Parameters

iterator: An I/O Kit iterator handle.

Discussion

If an iterator is invalid, or if the caller wants to start over, IOIteratorReset will set the iteration back to the beginning.

IOKitGetBusyState

Returns the busyState of all IOService objects.

kern_return_t IOKitGetBusyState( 
    mach_port_t masterPort, 
    uint32_t *busyState );

Parameters

masterPort: The master port obtained from IOMasterPort. Pass kIOMasterPortDefault to look up the default master port.
busyState: The busyState count is returned.

Return Value

A kern_return_t error code.

Discussion

Many activities in IOService are asynchronous. When registration, matching, or termination is in progress on an IOService object, its busyState is increased by one. Change in busyState to or from zero also changes the IOService object's provider's busyState by one, which means that an IOService object is marked busy when any of the above activities is ocurring on it or any of its clients. IOKitGetBusyState returns the busy state of the root of the service plane, which reflects the busy state of all IOService objects.

IOKitWaitQuiet

Waits for the busyState of all IOService objects to be zero.

kern_return_t IOKitWaitQuiet( 
    mach_port_t masterPort, 
    mach_timespec_t *waitTime );

Parameters

masterPort: The master port obtained from IOMasterPort. Pass kIOMasterPortDefault to look up the default master port.
waitTime: Specifies a maximum time to wait.

Return Value

Returns an error code if Mach synchronization primitives fail, kIOReturnTimeout, or kIOReturnSuccess.

Discussion

Blocks the caller until all IOService objects are non busy, see IOKitGetBusyState.

IOMasterPort

Returns the Mach port used to initiate communication with the I/O Kit.

kern_return_t IOMasterPort(
    mach_port_t bootstrapPort, 
    mach_port_t *masterPort );

Parameters

bootstrapPort: Pass MACH_PORT_NULL for the default.
masterPort: The master port is returned.

Return Value

A kern_return_t error code.

Discussion

Functions that don't specify an existing object require the I/O Kit master port to be passed. This function obtains that port.

IONotificationPortCreate

Creates and returns a notification object for receiving I/O Kit notifications of new devices or state changes.

IONotificationPortRef IONotificationPortCreate( 
    mach_port_t masterPort );

Parameters

masterPort: The master port obtained from IOMasterPort. Pass kIOMasterPortDefault to look up the default master port.

Return Value

A reference to the notification object.

Discussion

Creates the notification object to receive notifications from the I/O Kit of new device arrivals or state changes. The notification object can be supply a CFRunLoopSource, or mach_port_t to be used to listen for events.

IONotificationPortDestroy

Destroys a notification object created with IONotificationPortCreate.

void IONotificationPortDestroy( 
    IONotificationPortRef notify );

Parameters

notify: A reference to the notification object.

IONotificationPortGetMachPort

Returns a Mach port to be used to listen for notifications.

mach_port_t IONotificationPortGetMachPort( 
    IONotificationPortRef notify );

Parameters

notify: The notification object.

Return Value

A mach_port_t for the notification object.

Discussion

A notification object may deliver notifications to a Mach messaging client if they listen for messages on the port obtained from this function. Callbacks associated with the notifications may be delivered by calling IODispatchCalloutFromMessage with messages received.

IONotificationPortGetRunLoopSource

Returns a CFRunLoopSource to be used to listen for notifications.

CFRunLoopSourceRef IONotificationPortGetRunLoopSource( 
    IONotificationPortRef notify );

Parameters

notify: The notification object.

Return Value

A CFRunLoopSourceRef for the notification object.

Discussion

A notification object may deliver notifications to a CFRunLoop client by adding the run loop source returned by this function to the run loop.

IOObjectConformsTo

Performs an OSDynamicCast operation on an I/O Kit object.

boolean_t IOObjectConformsTo( 
    io_object_t object, 
    const io_name_t className );

Parameters

object: An I/O Kit object.
className: The name of the class, as a C string.

Return Value

If the object handle is valid, and represents an object in the kernel that dynamic casts to the class true is returned, otherwise false.

Discussion

This function uses the OSMetaClass system in the kernel to determine if the object will dynamic cast to a class, specified as a C string (in other words, if the object is of that class or a subclass).

IOObjectCopyBundleIdentifierForClass IOObjectCopyBundleIdentifierForClass

Returns the bundle identifier of the given class.

CFStringRef IOObjectCopyBundleIdentifierForClass(
    CFStringRef classname);

Parameters

classname: The name of the class as a CFString.

Return Value

The resulting CFStringRef. This should be released by the caller. If a valid class name is not passed in, then NULL is returned.

Discussion

This function uses the OSMetaClass system in the kernel to derive the name of the kmod, which is the same as the bundle identifier.

IOObjectCopyClass IOObjectCopyClass

Returns the class name of an I/O Kit object.

CFStringRef IOObjectCopyClass(
    io_object_t object) ;

Parameters

object: The I/O Kit object.

Return Value

The resulting CFStringRef. This should be released by the caller. If a valid object is not passed in, then NULL is returned.

Discussion

This function does the same thing as IOObjectGetClass, but returns the result as a CFStringRef.

Availability: Introduced in Mac OS X v10.4.

IOObjectCopySuperclassForClass IOObjectCopySuperclassForClass

Returns the superclass name of the given class.

CFStringRef IOObjectCopySuperclassForClass(
    CFStringRef classname);

Parameters

classname: The name of the class as a CFString.

Return Value

The resulting CFStringRef. This should be released by the caller. If there is no superclass, or a valid class name is not passed in, then NULL is returned.

Discussion

This function uses the OSMetaClass system in the kernel to derive the name of the superclass of the class.

IOObjectGetClass

Returns the class name of an I/O Kit object.

kern_return_t IOObjectGetClass( 
    io_object_t object, 
    io_name_t className );

Parameters

object: The I/O Kit object.
className: Caller allocated buffer to receive the name string.

Return Value

A kern_return_t error code.

Discussion

This function uses the OSMetaClass system in the kernel to derive the name of the class the object is an instance of.

IOObjectGetRetainCount

Returns kernel retain count of an I/O Kit object.

uint32_t IOObjectGetRetainCount( 
    io_object_t object );

Parameters

object: An I/O Kit object.

Return Value

If the object handle is valid, the kernel objects retain count is returned, otherwise zero is returned.

Discussion

This function may be used in diagnostics to determine the current retain count of the kernel object.

IOObjectIsEqualTo

Checks two object handles to see if they represent the same kernel object.

boolean_t IOObjectIsEqualTo( 
    io_object_t object, 
    io_object_t anObject );

Parameters

object: An I/O Kit object.
anObject: Another I/O Kit object.

Return Value

If both object handles are valid, and represent the same object in the kernel true is returned, otherwise false.

Discussion

If two object handles are returned by IOKitLib functions, this function will compare them to see if they represent the same kernel object.

IOObjectRelease

Releases an object handle previously returned by IOKitLib.

kern_return_t IOObjectRelease( 
    io_object_t object );

Parameters

object: The I/O Kit object to release.

Return Value

A kern_return_t error code.

Discussion

All objects returned by IOKitLib should be released with this function when access to them is no longer needed. Using the object after it has been released may or may not return an error, depending on how many references the task has to the same object in the kernel.

IOObjectRetain

Retains an object handle previously returned by IOKitLib.

kern_return_t IOObjectRetain( 
    io_object_t object );

Parameters

object: The I/O Kit object to retain.

Return Value

A kern_return_t error code.

Discussion

Gives the caller an additional reference to an existing object handle previously returned by IOKitLib.

IOOpenFirmwarePathMatching

Creates a matching dictionary that specifies an IOService match based on an OpenFirmware device path.

CFMutableDictionaryRef IOOpenFirmwarePathMatching( 
    mach_port_t masterPort, 
    uint32_t options, 
    const char *path );

Parameters

masterPort: The master port obtained from IOMasterPort. Pass kIOMasterPortDefault to look up the default master port.
options: No options are currently defined.
path: The OpenFirmware device path, as a const char pointer.

Return Value

Discussion

Certain IOService objects (currently, block and ethernet boot devices) may be looked up by a path that specifies their location in the OpenFirmware device tree, represented in the I/O Registry by the kIODeviceTreePlane plane. This function creates a matching dictionary that will match IOService objects found with a given OpenFirmware device path.

IORegistryCreateIterator

Creates an iterator rooted at the I/O Registry root.

kern_return_t IORegistryCreateIterator( 
    mach_port_t masterPort, 
    const io_name_t plane, 
    IOOptionBits options, 
    io_iterator_t *iterator );

Parameters

masterPort: The master port obtained from IOMasterPort. Pass kIOMasterPortDefault to look up the default master port.
plane: The name of an existing I/O Registry plane. Plane names are defined in IOKitKeys.h, eg. kIOServicePlane.
options: kIORegistryIterateRecursively may be set to recurse automatically into each entry as it is returned from calls on the registry iterator.
iterator: A created iterator handle, to be released by the caller when it has finished with it.

Return Value

A kern_return_t error code.

Discussion

This method creates an IORegistryIterator object in the kernel that is set up with options to iterate over the children of the I/O Registry root entry, and to recurse automatically into entries as they are returned, or only when instructed with calls to IORegistryIteratorEnterEntry. The iterator object keeps track of entries that have been recursed into previously to avoid loops.

IORegistryEntryCreateCFProperties

Creates a CFDictionary representation of a registry entry's property table.

kern_return_t IORegistryEntryCreateCFProperties( 
    io_registry_entry_t entry, 
    CFMutableDictionaryRef *properties, 
    CFAllocatorRef allocator, 
    IOOptionBits options );

Parameters

entry: The registry entry handle whose property table to copy.
properties: A CFDictionary is created and returned the caller on success. The caller should release with CFRelease.
allocator: The CF allocator to use when creating the CF containers.
options: No options are currently defined.

Return Value

A kern_return_t error code.

Discussion

This function creates an instantaneous snapshot of a registry entry's property table, creating a CFDictionary analogue in the caller's task. Not every object available in the kernel is represented as a CF container; currently OSDictionary, OSArray, OSSet, OSSymbol, OSString, OSData, OSNumber, OSBoolean are created as their CF counterparts.

IORegistryEntryCreateCFProperty

Creates a CF representation of a registry entry's property.

CFTypeRef IORegistryEntryCreateCFProperty( 
    io_registry_entry_t entry, 
    CFStringRef key, 
    CFAllocatorRef allocator, 
    IOOptionBits options );

Parameters

entry: The registry entry handle whose property to copy.
key: A CFString specifying the property name.
allocator: The CF allocator to use when creating the CF container.
options: No options are currently defined.

Return Value

A CF container is created and returned the caller on success. The caller should release with CFRelease.

Discussion

IORegistryEntryCreateIterator

Creates an iterator rooted at a given registry entry.

kern_return_t IORegistryEntryCreateIterator( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    IOOptionBits options, 
    io_iterator_t *iterator );

Parameters

entry: The root entry to begin the iteration at.
plane: The name of an existing I/O Registry plane. Plane names are defined in IOKitKeys.h, eg. kIOServicePlane.
options: kIORegistryIterateRecursively may be set to recurse automatically into each entry as it is returned from calls on the registry iterator. kIORegistryIterateParents may be set to iterate the parents of each entry, by default the children are iterated.
iterator: A created iterator handle, to be released by the caller when it has finished with it.

Return Value

A kern_return_t error code.

Discussion

This method creates an IORegistryIterator object in the kernel that is set up with options to iterate over the children or parents of a root entry, and to recurse automatically into entries as they are returned, or only when instructed with calls to IORegistryIteratorEnterEntry. The iterator object keeps track of entries that have been recursed into previously to avoid loops.

IORegistryEntryFromPath

Looks up a registry entry by path.

io_registry_entry_t IORegistryEntryFromPath( 
    mach_port_t masterPort, 
    const io_string_t path );

Parameters

masterPort: The master port obtained from IOMasterPort. Pass kIOMasterPortDefault to look up the default master port.
path: A C string path.

Return Value

A handle to the IORegistryEntry object that was found with the path (to be released with IOObjectRelease by the caller) or MACH_PORT_NULL on failure.

Discussion

This function parses paths to look up registry entries. The path should begin with '<plane name>:' If there are characters remaining unparsed after an entry has been looked up, this is considered an invalid lookup. Paths are further documented in IORegistryEntry.h.

IORegistryEntryGetChildEntry

Returns the first child of a registry entry in a plane.

kern_return_t IORegistryEntryGetChildEntry( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    io_registry_entry_t *child );

Parameters

entry: The registry entry whose child to look up.
plane: The name of an existing registry plane. Plane names are defined in IOKitKeys.h, e.g. kIOServicePlane.
child: The first child of the registry entry, on success. The child must be released by the caller.

Return Value

A kern_return_t error code.

Discussion

This function will return the child that first attached to a registry entry in a plane.

IORegistryEntryGetChildIterator

Returns an iterator over a registry entry's child entries in a plane.

kern_return_t IORegistryEntryGetChildIterator( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    io_iterator_t *iterator );

Parameters

entry: The registry entry whose children to iterate over.
plane: The name of an existing I/O Registry plane. Plane names are defined in IOKitKeys.h, e.g. kIOServicePlane.
iterator: The created iterator over the children of the entry, on success. The iterator must be released when the iteration is finished.

Return Value

A kern_return_t error code.

Discussion

This method creates an iterator which will return each of a registry entry's child entries in a specified plane.

IORegistryEntryGetLocationInPlane

Returns a C string location assigned to a registry entry, in a specified plane.

kern_return_t IORegistryEntryGetLocationInPlane( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    io_name_t location );

Parameters

entry: The registry entry handle whose name to look up.
plane: The name of an existing registry plane. Plane names are defined in IOKitKeys.h, eg. kIOServicePlane.
location: The caller's buffer to receive the location string.

Return Value

A kern_return_t error code.

Discussion

Registry entries can given a location string in a particular plane, or globally. If the entry has had a location set in the specified plane that location string will be returned, otherwise the global location string is returned. If no global location string has been set, an error is returned.

IORegistryEntryGetName

Returns a C string name assigned to a registry entry.

kern_return_t IORegistryEntryGetName( 
    io_registry_entry_t entry, 
    io_name_t name );

Parameters

entry: The registry entry handle whose name to look up.
name: The caller's buffer to receive the name.

Return Value

A kern_return_t error code.

Discussion

Registry entries can be named in a particular plane or globally. This function returns the entry's global name. The global name defaults to the entry's meta class name if it has not been named.

IORegistryEntryGetNameInPlane

Returns a C string name assigned to a registry entry, in a specified plane.

kern_return_t IORegistryEntryGetNameInPlane( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    io_name_t name );

Parameters

entry: The registry entry handle whose name to look up.
plane: The name of an existing registry plane. Plane names are defined in IOKitKeys.h, e.g. kIOServicePlane.
name: The caller's buffer to receive the name.

Return Value

A kern_return_t error code.

Discussion

Registry entries can be named in a particular plane, or globally. This function returns the entry's name in the specified plane or global name if it has not been named in that plane. The global name defaults to the entry's meta class name if it has not been named.

IORegistryEntryGetParentEntry

Returns the first parent of a registry entry in a plane.

kern_return_t IORegistryEntryGetParentEntry( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    io_registry_entry_t *parent );

Parameters

entry: The registry entry whose parent to look up.
plane: The name of an existing registry plane. Plane names are defined in IOKitKeys.h, e.g. kIOServicePlane.
parent: The first parent of the registry entry, on success. The parent must be released by the caller.

Return Value

A kern_return_t error code.

Discussion

This function will return the parent to which the registry entry was first attached in a plane.

IORegistryEntryGetParentIterator

Returns an iterator over a registry entry's parent entries in a plane.

kern_return_t IORegistryEntryGetParentIterator( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    io_iterator_t *iterator );

Parameters

entry: The registry entry whose parents to iterate over.
plane: The name of an existing registry plane. Plane names are defined in IOKitKeys.h, e.g. kIOServicePlane.
iterator: The created iterator over the parents of the entry, on success. The iterator must be released when the iteration is finished.

Return Value

A kern_return_t error.

Discussion

This method creates an iterator which will return each of a registry entry's parent entries in a specified plane.

IORegistryEntryGetPath

Creates a path for a registry entry.

kern_return_t IORegistryEntryGetPath( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    io_string_t path );

Parameters

entry: The registry entry handle whose path to look up.
plane: The name of an existing registry plane. Plane names are defined in IOKitKeys.h, e.g. kIOServicePlane.
path: A char buffer allocated by the caller.

Return Value

IORegistryEntryGetPath will fail if the entry is not attached in the specified plane, or if the buffer is not large enough to contain the path.

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. An alias may also exist for the entry, and will be returned if available.

IORegistryEntryInPlane

Determines if the registry entry is attached in a plane.

boolean_t IORegistryEntryInPlane( 
    io_registry_entry_t entry, 
    const io_name_t plane );

Parameters

entry: The registry entry.
plane: The name of an existing registry plane. Plane names are defined in IOKitKeys.h, eg. kIOServicePlane.

Return Value

If the entry has a parent in the plane, true is returned, otherwise false is returned.

Discussion

This method determines if the entry is attached in a plane to any other entry.

IORegistryEntrySearchCFProperty

Creates a CF representation of a registry entry's property.

CFTypeRef IORegistryEntrySearchCFProperty( 
    io_registry_entry_t entry, 
    const io_name_t plane, 
    CFStringRef key, 
    CFAllocatorRef allocator, 
    IOOptionBits options );

Parameters

entry: The registry entry at which to start the search.
plane: The name of an existing registry plane. Plane names are defined in IOKitKeys.h, eg. kIOServicePlane.
key: A CFString specifying the property name.
allocator: The CF allocator to use when creating the CF container.
options: kIORegistryIterateRecursively may be set to recurse automatically into the registry hierarchy. Without this option, this method degenerates into the standard IORegistryEntryCreateCFProperty call. kIORegistryIterateParents may be set to iterate the parents of the entry, in place of the children.

Return Value

A CF container is created and returned the caller on success. The caller should release with CFRelease.

Discussion

This function creates an instantaneous snapshot of a registry entry property, creating a CF container analogue in the caller's task. Not every object available in the kernel is represented as a CF container; currently OSDictionary, OSArray, OSSet, OSSymbol, OSString, OSData, OSNumber, OSBoolean are created as their CF counterparts. This function will search for a property, starting first with the specified registry entry's property table, then iterating recusively through either the parent registry entries or the child registry entries of this entry. Once the first occurrence is found, it will look up and return the value of the property, using the same semantics as IORegistryEntryCreateCFProperty. The iteration keeps track of entries that have been recursed into previously to avoid loops.

IORegistryEntrySetCFProperties

Sets CF container-based properties in a registry entry.

kern_return_t IORegistryEntrySetCFProperties( 
    io_registry_entry_t entry, 
    CFTypeRef properties );

Parameters

entry: The registry entry whose properties to set.
properties: A CF container - commonly a CFDictionary but this is not enforced. The container should consist of objects which are understood by the I/O Kit - these are currently : CFDictionary, CFArray, CFSet, CFString, CFData, CFNumber, CFBoolean, and are passed in the kernel as the corresponding OSDictionary etc. objects.

Return Value

A kern_return_t error code returned by the object.

Discussion

This is a generic method to pass a CF container of properties to an object in the I/O Registry. Setting properties in a registry entry is not generally supported; it is more common to support IOConnectSetCFProperties for connection-based property setting. The properties are interpreted by the object.

IORegistryEntrySetCFProperty

Sets a CF container-based property in a registry entry.

kern_return_t IORegistryEntrySetCFProperty( 
    io_registry_entry_t entry, 
    CFStringRef propertyName, 
    CFTypeRef property );

Parameters

entry: The registry entry whose property to set.
propertyName: The name of the property as a CFString.
property: A CF container - should consist of objects which are understood by the I/O Kit - these are currently : CFDictionary, CFArray, CFSet, CFString, CFData, CFNumber, CFBoolean, and are passed in the kernel as the corresponding OSDictionary etc. objects.

Return Value

A kern_return_t error code returned by the object.

Discussion

This is a generic method to pass a CF container as a property to an object in the I/O Registry. Setting properties in a registry entry is not generally supported, it is more common to support IOConnectSetCFProperty for connection-based property setting. The property is interpreted by the object.

IORegistryGetRootEntry

Returns a handle to the I/O Registry root.

io_registry_entry_t IORegistryGetRootEntry( 
    mach_port_t masterPort );

Parameters

masterPort: The master port obtained from IOMasterPort. Pass kIOMasterPortDefault to look up the default master port.

Return Value

A handle to the IORegistryEntry root instance (to be released with IOObjectRelease by the caller) or MACH_PORT_NULL on failure.

Discussion

This method provides an accessor to the root of the I/O Registry for the machine. The root may be passed to a registry iterator object when iterating a plane, and contains properties that describe the available planes, and diagnostic information for the I/O Kit.

IORegistryIteratorEnterEntry

Recurses into the current entry in the registry iteration.

kern_return_t IORegistryIteratorEnterEntry( 
    io_iterator_t iterator );

Return Value

A kern_return_t error code.

Discussion

This method makes the current entry, i.e. the last entry returned by IOIteratorNext, the root in a new level of recursion.