Add a simple build script for Windows with Visual Studio

Keep it simple and mostly non-parametrizable for now.
A path to Visual Studio 2017 is hard-coded.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/windows_msbuild.bat b/scripts/windows_msbuild.bat
new file mode 100644
index 0000000..e419931
--- /dev/null
+++ b/scripts/windows_msbuild.bat
@@ -0,0 +1,20 @@
+@rem Build and test Mbed TLS with Visual Studio using msbuild.

+@rem Usage: windows_msbuild [RETARGET]

+@rem   RETARGET: version of Visual Studio to emulate

+@rem             https://docs.microsoft.com/en-us/cpp/build/how-to-modify-the-target-framework-and-platform-toolset

+

+@rem These parameters are hard-coded for now.

+set "arch=x64" & @rem "x86" or "x64"

+set "cfg=Release" & @rem "Debug" or "Release"

+set "vcvarsall=C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Auxiliary\Build\vcvarsall.bat"

+

+if not "%~1"=="" set "retarget=,PlatformToolset=%1"

+

+@rem If the %USERPROFILE%\Source directory exists, then running

+@rem vcvarsall.bat will silently change the directory to that directory.

+@rem Setting the VSCMD_START_DIR environment variable causes it to change

+@rem to that directory instead.

+set "VSCMD_START_DIR=%~dp0\..\visualc\VS2010"

+

+"%vcvarsall%" x64 && ^

+msbuild /t:Rebuild /p:Configuration=%cfg%%retarget% /m mbedTLS.sln