---
title: Start
framework: driverkit
role: symbol
role_heading: Instance Method
path: driverkit/ioservice/start
---

# Start

Starts the current service and associates it with the specified provider.

## Declaration

```occ
virtual kern_return_t Start(IOService *provider);
```

## Parameters

- `provider`: The provider object that matches the current service. Cast this object to the class you expect. The system retains this object for the duration of your doc://com.apple.documentation/documentation/SerialDriverKit/IOUserSerial/Start method. The system continues to retain the object if your service starts successfully, releasing it only after calling your service’s doc://com.apple.documentation/documentation/SerialDriverKit/IOUserSerial/Stop method.

## Mentioned in

Creating a Driver Using the DriverKit SDK

## Return Value

Return Value kIOReturnSuccess on success, or another value if an error occurs. For a list of error codes, see Error Codes.

## Discussion

Discussion After successfully matching the specified provider to your driver’s service, the system instantiates your service object and calls this method. Use this method to configure your driver’s data structures and setup the associated hardware. You might also store a reference to the provider object for later use. After you configure your driver, call the RegisterService method to let the system know your service is running. Always call super early in your implementation of this method.

## See Also

### Running the Service

- [init](driverkit/ioservice/init.md)
- [Stop](driverkit/ioservice/stop.md)
- [free](driverkit/ioservice/free.md)