---
title: CreateMapping
framework: driverkit
role: symbol
role_heading: Instance Method
path: driverkit/iomemorydescriptor/createmapping
---

# CreateMapping

Maps the contents of the memory block to the address space of the current process.

## Declaration

```occ
virtual kern_return_t CreateMapping(uint64_t options, uint64_t address, uint64_t offset, uint64_t length, uint64_t alignment, IOMemoryMap **map);
```

## Parameters

- `options`: The options to use when mapping the memory into this process. For a list of possible values, see doc://com.apple.driverkit/documentation/DriverKit/3325558-memory_map_options.
- `address`: The address in the current process’ memory space at which to place the memory block. Specify a value for this parameter only if you also specified the doc://com.apple.driverkit/documentation/DriverKit/kIOMemoryMapFixedAddress option; otherwise, specify 0.
- `offset`: The offset into the buffer to use as the first byte. Specify a value for this parameter only if you want to map from somewhere other than the first byte of the buffer; otherwise, specify 0.
- `length`: The number of bytes accessible to the memory mapping. Specify 0 to map the entire buffer into memory, or specify a value that is less than the current length of the buffer.
- `alignment`: The byte alignment to use when mapping the memory into your process. Specify only 0 for this parameter.
- `map`: A variable in which to store the newly created doc://com.apple.driverkit/documentation/DriverKit/IOMemoryMap object. The returned object has a retain count of 1. You are responsible for releasing this object when you are finished with it.

## Return Value

Return Value kIOReturnSuccess on success, or another value if an error occurs. See Error Codes.

## Discussion

Discussion Use this method to map a memory buffer created by another process into the address space of the current process.

## See Also

### Mapping to the Caller’s Address Space

- [Memory Map Options](driverkit/3325558-memory_map_options.md)