Native plug-in and internal call support

To call native functions, use [DllImport]:

[DllImport("MyNativeLibrary")]
public static extern int Foo(int arg);

Burst also supports internal calls implemented inside Unity:

// In UnityEngine.Mathf
[MethodImpl(MethodImplOptions.InternalCall)]
public static extern int ClosestPowerOfTwo(int value);

DllImport is only supported for native plug-insA platform-specific native code library that is created outside of Unity for use in Unity. Allows you can access features like OS calls and third-party code libraries that would otherwise not be available to Unity. More info
See in Glossary, not platform-dependent libraries like kernel32.dll.

For all DllImport and internal calls, you can only use the following types as parameter or return types:

Note: Passing structs by value isn’t supported; you need to pass them through a pointer or reference. The only exception is that handle structs are supported. These are structs that contain a single field of pointer or integer type.

Additional resources

• HPC# overview
• Burst intrinsics overview