1Build Prerequisites: 2 3 * CMake[1] 2.8.8 or later is required. 4 5 * Perl 5.6.1 or later is required. On Windows, Strawberry Perl and MSYS Perl 6 have both been reported to work. If not found by CMake, it may be configured 7 explicitly by setting PERL_EXECUTABLE. 8 9 * On Windows you currently must use Ninja[2] to build; on other platforms, 10 it is not required, but recommended, because it makes builds faster. 11 12 * If you need to build Ninja from source, then a recent version of 13 Python[3] is required (Python 2.7.5 works). 14 15 * On Windows only, Yasm[4] is required. If not found by CMake, it may be 16 configured explicitly by setting CMAKE_ASM_NASM_COMPILER. 17 18 * A C compiler is required. On Windows, MSVC 12 (Visual Studio 2013) or later 19 with Platform SDK 8.1 or later are supported. Recent versions of GCC and 20 Clang should work on non-Windows platforms, and maybe on Windows too. 21 22 * Go[5] is required. If not found by CMake, the go executable may be 23 configured explicitly by setting GO_EXECUTABLE. 24 25Using Ninja (note the 'N' is capitalized in the cmake invocation): 26 27 mkdir build 28 cd build 29 cmake -GNinja .. 30 ninja 31 32Using makefiles (does not work on Windows): 33 34 mkdir build 35 cd build 36 cmake .. 37 make 38 39You usually don't need to run cmake again after changing CMakeLists.txt files 40because the build scripts will detect changes to them and rebuild themselves 41automatically. 42 43Note that the default build flags in the top-level CMakeLists.txt are for 44debugging - optimisation isn't enabled. 45 46If you want to cross-compile then there is an example toolchain file for 4732-bit Intel in util/. Wipe out the build directory, recreate it and run cmake 48like this: 49 50 cmake -DCMAKE_TOOLCHAIN_FILE=../util/32-bit-toolchain.cmake -GNinja .. 51 52If you want to build as a shared library, pass -DBUILD_SHARED_LIBS=1. On 53Windows, where functions need to be tagged with "dllimport" when coming from a 54shared library, define BORINGSSL_SHARED_LIBRARY in any code which #includes the 55BoringSSL headers. 56 57 58Building for Android: 59 60It's possible to build BoringSSL with the Android NDK using CMake. This has 61been tested with version 10d of the NDK. 62 63Unpack the Android NDK somewhere and export ANDROID_NDK to point to the 64directory. Clone https://github.com/taka-no-me/android-cmake into util/. 65Then make a build directory as above and run CMake *twice* like this: 66 67 cmake -DANDROID_NATIVE_API_LEVEL=android-9 \ 68 -DANDROID_ABI=armeabi-v7a \ 69 -DCMAKE_TOOLCHAIN_FILE=../util/android-cmake/android.toolchain.cmake \ 70 -GNinja .. 71 72Once you've run that twice, ninja should produce Android-compatible binaries. 73You can replace "armeabi-v7a" in the above with "arm64-v8a" to build aarch64 74binaries. 75 76 77Known Limitations on Windows: 78 79 * Versions of cmake since 3.0.2 have a bug in its Ninja generator that causes 80 yasm to output warnings "yasm: warning: can open only one input file, only 81 the last file will be processed". These warnings can be safely ignored. 82 The cmake bug is http://www.cmake.org/Bug/view.php?id=15253. 83 84 * cmake can generate Visual Studio projects, but the generated project files 85 don't have steps for assembling the assembly language source files, so they 86 currently cannot be used to build BoringSSL. 87 88[1] http://www.cmake.org/download/ 89 90[2] https://martine.github.io/ninja/ 91 92[3] https://www.python.org/downloads/ 93 94[4] http://yasm.tortall.net/ 95 96[5] https://golang.org/dl/ 97