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Create core library
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To implement its own core library, MOSA generates a "dummy" one that includes all the public APIs but without the actual implementation code. The **Create core library** utility takes care of doing that work. To clone the official .NET core library repository, it requires ``git``. Here are the available command line arguments for the utility:

.. csv-table::
   :header: "Short name","Long name","Description"
   :widths: 100, 100, 50

    -o,\-\-output,Sets the output directory.
    -c,\-\-copy-files,"If enabled, only copies and patches the source files and stops."

To run the utility, simply execute the following command on any platform:

.. code-block:: bash

	dotnet bin/Mosa.Utility.CreateCoreLib.dll -o Output

The process can take between a few seconds to a few minutes depending on the speed of your internet connection and PC. At the end, you should get a ``System.Runtime.dll`` file at the directory where you executed the utility. At the end, you should get a console output that looks like this:

.. code-block:: text

  Cloning .NET runtime GitHub repository...
  Cloning into 'runtime'...
  remote: Enumerating objects: 65953, done.
  remote: Counting objects: 100% (65953/65953), done.
  remote: Compressing objects: 100% (42248/42248), done.
  Receiving objects: 100% (65953/65953), 88.04 MiB | 9.16 MiB/s, done.
  remote: Total 65953 (delta 25898), reused 34761 (delta 20956), pack-reused 0 (from 0)
  Resolving deltas: 100% (25898/25898), done.
  Updating files: 100% (58901/58901), done.
  Parsing input files...
  Patching System.DirectoryServices.manual.cs...
  Patching System.Net.Http.Json.cs...
  Patching System.Net.Http.WinHttpHandler.cs...
  Patching System.Configuration.ConfigurationManager.cs...
  Patching System.Data.Common.cs...
  Compiling source files...
  Decompiling assembly...
  Removing project file...
  Removing Properties folder...
  Patching System.Collections.Generic/PriorityQueue.cs...
  Patching System.Collections.Generic/PriorityQueue.cs...
  Patching System/Nullable.cs...
  Patching System/ReadOnlySpan.cs...
  Patching System.Runtime.InteropServices/Marshal.cs...
  Patching System.Runtime.InteropServices/MemoryMarshal.cs...
  Patching System.Runtime.CompilerServices/Unsafe.cs...
  Patching System.Numerics/Vector.cs...
  Patching System.Runtime.Intrinsics/Vector64.cs...
  Patching System.Runtime.Intrinsics/Vector128.cs...
  Patching System.Runtime.Intrinsics/Vector256.cs...
  Patching System.Runtime.Intrinsics/Vector512.cs...
  Patching System.Threading/Volatile.cs...
  Patching System.Threading/Interlocked.cs...