1*4724848cSchristos 2*4724848cSchristos NOTES FOR ANDROID PLATFORMS 3*4724848cSchristos =========================== 4*4724848cSchristos 5*4724848cSchristos Requirement details 6*4724848cSchristos ------------------- 7*4724848cSchristos 8*4724848cSchristos Beside basic tools like perl and make you'll need to download the Android 9*4724848cSchristos NDK. It's available for Linux, macOS and Windows, but only Linux 10*4724848cSchristos version was actually tested. There is no reason to believe that macOS 11*4724848cSchristos wouldn't work. And as for Windows, it's unclear which "shell" would be 12*4724848cSchristos suitable, MSYS2 might have best chances. NDK version should play lesser 13*4724848cSchristos role, the goal is to support a range of most recent versions. 14*4724848cSchristos 15*4724848cSchristos Configuration 16*4724848cSchristos ------------- 17*4724848cSchristos 18*4724848cSchristos Android is a naturally cross-compiled target and you can't use ./config. 19*4724848cSchristos You have to use ./Configure and name your target explicitly; there are 20*4724848cSchristos android-arm, android-arm64, android-mips, android-mip64, android-x86 21*4724848cSchristos and android-x86_64 (*MIPS targets are no longer supported with NDK R20+). 22*4724848cSchristos Do not pass --cross-compile-prefix (as you might be tempted), as it will 23*4724848cSchristos be "calculated" automatically based on chosen platform. Though you still 24*4724848cSchristos need to know the prefix to extend your PATH, in order to invoke 25*4724848cSchristos $(CROSS_COMPILE)clang [*gcc on NDK 19 and lower] and company. (Configure 26*4724848cSchristos will fail and give you a hint if you get it wrong.) Apart from PATH 27*4724848cSchristos adjustment you need to set ANDROID_NDK_HOME environment to point at the 28*4724848cSchristos NDK directory. If you're using a side-by-side NDK the path will look 29*4724848cSchristos something like /some/where/android-sdk/ndk/<ver>, and for a standalone 30*4724848cSchristos NDK the path will be something like /some/where/android-ndk-<ver>. 31*4724848cSchristos Both variables are significant at both configuration and compilation times. 32*4724848cSchristos The NDK customarily supports multiple Android API levels, e.g. android-14, 33*4724848cSchristos android-21, etc. By default latest API level is chosen. If you need to 34*4724848cSchristos target an older platform pass the argument -D__ANDROID_API__=N to Configure, 35*4724848cSchristos with N being the numerical value of the target platform version. For example, 36*4724848cSchristos to compile for Android 10 arm64 with a side-by-side NDK r20.0.5594570 37*4724848cSchristos 38*4724848cSchristos export ANDROID_NDK_HOME=/home/whoever/Android/android-sdk/ndk/20.0.5594570 39*4724848cSchristos PATH=$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin:$ANDROID_NDK_HOME/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin:$PATH 40*4724848cSchristos ./Configure android-arm64 -D__ANDROID_API__=29 41*4724848cSchristos make 42*4724848cSchristos 43*4724848cSchristos Older versions of the NDK have GCC under their common prebuilt tools directory, so the bin path 44*4724848cSchristos will be slightly different. EG: to compile for ICS on ARM with NDK 10d: 45*4724848cSchristos 46*4724848cSchristos export ANDROID_NDK_HOME=/some/where/android-ndk-10d 47*4724848cSchristos PATH=$ANDROID_NDK_HOME/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86_64/bin:$PATH 48*4724848cSchristos ./Configure android-arm -D__ANDROID_API__=14 49*4724848cSchristos make 50*4724848cSchristos 51*4724848cSchristos Caveat lector! Earlier OpenSSL versions relied on additional CROSS_SYSROOT 52*4724848cSchristos variable set to $ANDROID_NDK_HOME/platforms/android-<api>/arch-<arch> to 53*4724848cSchristos appoint headers-n-libraries' location. It's still recognized in order 54*4724848cSchristos to facilitate migration from older projects. However, since API level 55*4724848cSchristos appears in CROSS_SYSROOT value, passing -D__ANDROID_API__=N can be in 56*4724848cSchristos conflict, and mixing the two is therefore not supported. Migration to 57*4724848cSchristos CROSS_SYSROOT-less setup is recommended. 58*4724848cSchristos 59*4724848cSchristos One can engage clang by adjusting PATH to cover same NDK's clang. Just 60*4724848cSchristos keep in mind that if you miss it, Configure will try to use gcc... 61*4724848cSchristos Also, PATH would need even further adjustment to cover unprefixed, yet 62*4724848cSchristos target-specific, ar and ranlib. It's possible that you don't need to 63*4724848cSchristos bother, if binutils-multiarch is installed on your Linux system. 64*4724848cSchristos 65*4724848cSchristos Another option is to create so called "standalone toolchain" tailored 66*4724848cSchristos for single specific platform including Android API level, and assign its 67*4724848cSchristos location to ANDROID_NDK_HOME. In such case you have to pass matching 68*4724848cSchristos target name to Configure and shouldn't use -D__ANDROID_API__=N. PATH 69*4724848cSchristos adjustment becomes simpler, $ANDROID_NDK_HOME/bin:$PATH suffices. 70*4724848cSchristos 71*4724848cSchristos Running tests (on Linux) 72*4724848cSchristos ------------------------ 73*4724848cSchristos 74*4724848cSchristos This is not actually supported. Notes are meant rather as inspiration. 75*4724848cSchristos 76*4724848cSchristos Even though build output targets alien system, it's possible to execute 77*4724848cSchristos test suite on Linux system by employing qemu-user. The trick is static 78*4724848cSchristos linking. Pass -static to Configure, then edit generated Makefile and 79*4724848cSchristos remove occurrences of -ldl and -pie flags. You would also need to pick 80*4724848cSchristos API version that comes with usable static libraries, 42/2=21 used to 81*4724848cSchristos work. Once built, you should be able to 82*4724848cSchristos 83*4724848cSchristos env EXE_SHELL=qemu-<arch> make test 84*4724848cSchristos 85*4724848cSchristos If you need to pass additional flag to qemu, quotes are your friend, e.g. 86*4724848cSchristos 87*4724848cSchristos env EXE_SHELL="qemu-mips64el -cpu MIPS64R6-generic" make test 88