IOKitdrivere

IOKitdrivere are device drivers built on Apple's I/O Kit, a modular framework used to manage hardware devices on macOS and iOS. They serve as the bridge between physical hardware and the operating system, handling tasks such as device initialization, I/O scheduling, and state management.

IOKit uses an object-oriented C++ framework with a hierarchical service registry called the I/O Registry. Drivers are implemented as subclassed I/O Kit objects (most commonly IOService) that bind to hardware via hardware events and a matching mechanism. The registry maintains properties describing devices, vendors, and capabilities, enabling the system to automatically locate and bind appropriate drivers.

Historically IOKit drivers shipped as kernel extensions (KEXTs) running in the kernel, but Apple has introduced DriverKit to support user-space drivers in recent macOS versions. DriverKit drivers reside outside the kernel, communicating with user processes through safe IPC and user-client interfaces. This separation improves stability and security, while still providing access to hardware features through standardized interfaces.

Development and distribution involve Xcode and the IOKit framework headers. Code is typically written in C++ and must adhere to kernel or system-extension signing and provisioning requirements. Drivers are loaded through system mechanisms, with Apple enforcing validations. IOKitdrivere play a critical role in expanding hardware support for Macs and iOS devices, including peripherals, embedded controllers, and custom devices.