---
title: IOKit Data Types
framework: IOKit
role: collectionGroup
role_heading: API Collection
path: iokit/iokit_data_types
---

# IOKit Data Types

## Topics

### Data Types

- [IOAddressRange](iokit/ioaddressrange.md)
- [IOAlignment](iokit/ioalignment.md)
- [IOByteCount](iokit/iobytecount.md)
- [IOByteCount32](iokit/iobytecount32.md)
- [IOByteCount64](iokit/iobytecount64.md)
- [IOCFPlugInInterfaceStruct](iokit/iocfplugininterfacestruct.md)
- [IOCacheMode](iokit/iocachemode.md)
- [IODataQueueAppendix](iokit/iodataqueueappendix.md)
- [IODataQueueEntry](iokit/iodataqueueentry.md)
- [IODataQueueMemory](iokit/iodataqueuememory.md)
- [IODeviceNumber](iokit/iodevicenumber.md)
- [IOFixed](iokit/iofixed.md)
- [IOItemCount](iokit/ioitemcount.md)
- [IOLogicalAddress](iokit/iologicaladdress.md)
- [IOMessage](iokit/iomessage.md)
- [IONotificationPortRef](iokit/ionotificationportref.md)
- [IOOptionBits](iokit/iooptionbits.md)
- [IOPhysicalAddress](iokit/iophysicaladdress.md)
- [IOPhysicalAddress32](iokit/iophysicaladdress32.md)
- [IOPhysicalAddress64](iokit/iophysicaladdress64.md)
- [IOPhysicalLength](iokit/iophysicallength.md)
- [IOPhysicalLength32](iokit/iophysicallength32.md)
- [IOPhysicalLength64](iokit/iophysicallength64.md)
- [IOReturn](iokit/ioreturn.md)
- [IOServiceInterestContent64](iokit/ioserviceinterestcontent64.md)
- [IOVersion](iokit/ioversion.md)
- [IOVirtualAddress](iokit/iovirtualaddress.md)
- [OSAsyncReference](iokit/osasyncreference.md)
- [OSAsyncReference64](iokit/osasyncreference64.md)
- [OSNotificationHeader64](iokit/osnotificationheader64.md)
- [io_connect_t](iokit/io_connect_t.md)
- [io_enumerator_t](iokit/io_enumerator_t.md)
- [io_iterator_t](iokit/io_iterator_t.md)
- [io_object_t](iokit/io_object_t.md)
- [io_registry_entry_t](iokit/io_registry_entry_t.md)
- [io_service_t](iokit/io_service_t.md)
- [OSObjectRef](iokit/osobjectref.md)
- [io_ident_t](iokit/io_ident_t.md)
- [uext_object_t](iokit/uext_object_t.md)