1 files changed, 96 insertions, 0 deletions
diff --git a/src/BUILDING b/src/BUILDING
new file mode 100644
index 0000000..d818f95
--- /dev/null
+++ b/src/BUILDING
@@ -0,0 +1,96 @@
+Build Prerequisites:
+
+  * CMake[1] 2.8.8 or later is required.
+
+  * Perl 5.6.1 or later is required. On Windows, Strawberry Perl and MSYS Perl
+    have both been reported to work. If not found by CMake, it may be configured
+    explicitly by setting PERL_EXECUTABLE.
+
+  * On Windows you currently must use Ninja[2] to build; on other platforms,
+    it is not required, but recommended, because it makes builds faster.
+
+  * If you need to build Ninja from source, then a recent version of
+    Python[3] is required (Python 2.7.5 works).
+
+  * On Windows only, Yasm[4] is required. If not found by CMake, it may be
+    configured explicitly by setting CMAKE_ASM_NASM_COMPILER.
+
+  * A C compiler is required. On Windows, MSVC 12 (Visual Studio 2013) or later
+    with Platform SDK 8.1 or later are supported. Recent versions of GCC and
+    Clang should work on non-Windows platforms, and maybe on Windows too.
+
+  * Go[5] is required. If not found by CMake, the go executable may be
+    configured explicitly by setting GO_EXECUTABLE.
+
+Using Ninja (note the 'N' is capitalized in the cmake invocation):
+
+  mkdir build
+  cd build
+  cmake -GNinja ..
+  ninja
+
+Using makefiles (does not work on Windows):
+
+  mkdir build
+  cd build
+  cmake ..
+  make
+
+You usually don't need to run cmake again after changing CMakeLists.txt files
+because the build scripts will detect changes to them and rebuild themselves
+automatically.
+
+Note that the default build flags in the top-level CMakeLists.txt are for
+debugging - optimisation isn't enabled.
+
+If you want to cross-compile then there is an example toolchain file for
+32-bit Intel in util/. Wipe out the build directory, recreate it and run cmake
+like this:
+
+  cmake -DCMAKE_TOOLCHAIN_FILE=../util/32-bit-toolchain.cmake -GNinja ..
+
+If you want to build as a shared library, pass -DBUILD_SHARED_LIBS=1. On
+Windows, where functions need to be tagged with "dllimport" when coming from a
+shared library, define BORINGSSL_SHARED_LIBRARY in any code which #includes the
+BoringSSL headers.
+
+
+Building for Android:
+
+It's possible to build BoringSSL with the Android NDK using CMake. This has
+been tested with version 10d of the NDK.
+
+Unpack the Android NDK somewhere and export ANDROID_NDK to point to the
+directory. Clone https://github.com/taka-no-me/android-cmake into util/.
+Then make a build directory as above and run CMake *twice* like this:
+
+  cmake -DANDROID_NATIVE_API_LEVEL=android-9 \
+        -DANDROID_ABI=armeabi-v7a \
+        -DCMAKE_TOOLCHAIN_FILE=../util/android-cmake/android.toolchain.cmake \
+        -GNinja ..
+
+Once you've run that twice, ninja should produce Android-compatible binaries.
+You can replace "armeabi-v7a" in the above with "arm64-v8a" to build aarch64
+binaries.
+
+
+Known Limitations on Windows:
+
+  * Versions of cmake since 3.0.2 have a bug in its Ninja generator that causes
+    yasm to output warnings "yasm: warning: can open only one input file, only
+    the last file will be processed". These warnings can be safely ignored.
+    The cmake bug is http://www.cmake.org/Bug/view.php?id=15253.
+
+  * cmake can generate Visual Studio projects, but the generated project files
+    don't have steps for assembling the assembly language source files, so they
+    currently cannot be used to build BoringSSL.
+
+[1] http://www.cmake.org/download/
+
+[2] https://martine.github.io/ninja/
+
+[3] https://www.python.org/downloads/
+
+[4] http://yasm.tortall.net/
+
+[5] https://golang.org/dl/