Support compiling for ARM Android

cross/android/arm/toolchain.cmake

@@ -0,0 +1,38 @@
+set(CROSS_NDK_TOOLCHAIN $ENV{ROOTFS_DIR}/..)
+set(CROSS_ROOTFS ${CROSS_NDK_TOOLCHAIN}/sysroot)
+set(CLR_CMAKE_PLATFORM_ANDROID "Android")
+
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_VERSION 1)
+set(CMAKE_SYSTEM_PROCESSOR arm)
+
+## Specify the toolchain
+set(TOOLCHAIN "arm-linux-androideabi")
+set(CMAKE_PREFIX_PATH ${CROSS_NDK_TOOLCHAIN})
+
+find_program(CMAKE_C_COMPILER ${TOOLCHAIN}-clang)
+find_program(CMAKE_CXX_COMPILER ${TOOLCHAIN}-clang++)
+find_program(CMAKE_ASM_COMPILER ${TOOLCHAIN}-clang)
+find_program(CMAKE_OBJCOPY ${TOOLCHAIN}-objcopy)
+find_program(CMAKE_OBJDUMP ${TOOLCHAIN}-objdump)
+
+add_compile_options(--sysroot=${CROSS_ROOTFS})
+add_compile_options(-fPIE)
+
+# Some libraries, like libcurl, check for the __ANDROID__ flag to include some required headers.
+add_compile_options(-D__ANDROID__)
+
+set(CROSS_LINK_FLAGS "${CROSS_LINK_FLAGS} -B ${CROSS_ROOTFS}/usr/lib/gcc/${TOOLCHAIN}")
+set(CROSS_LINK_FLAGS "${CROSS_LINK_FLAGS} -L${CROSS_ROOTFS}/lib/${TOOLCHAIN}")
+set(CROSS_LINK_FLAGS "${CROSS_LINK_FLAGS} --sysroot=\"${CROSS_ROOTFS}\"")
+set(CROSS_LINK_FLAGS "${CROSS_LINK_FLAGS} -fPIE -pie")
+
+set(CMAKE_EXE_LINKER_FLAGS    "${CMAKE_EXE_LINKER_FLAGS}    ${CROSS_LINK_FLAGS}" CACHE STRING "" FORCE)
+set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${CROSS_LINK_FLAGS}" CACHE STRING "" FORCE)
+set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${CROSS_LINK_FLAGS}" CACHE STRING "" FORCE)
+
+set(CMAKE_FIND_ROOT_PATH "${CROSS_ROOTFS}")
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

cross/android/arm/tryrun.cmake

@@ -0,0 +1,6 @@
+SET( HAVE_SHM_OPEN_THAT_WORKS_WELL_ENOUGH_WITH_MMAP_EXITCODE
+     0
+     CACHE STRING "Result from TRY_RUN" FORCE)
+SET( HAVE_CLOCK_MONOTONIC_EXITCODE
+     0
+     CACHE STRING "Result from TRY_RUN" FORCE)

cross/build-android-rootfs.sh

@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+__NDK_Version=r14
 
 usage()
 {
@@ -12,14 +13,15 @@ usage()
     echo "By default, the toolchain and sysroot will be generated in cross/android-rootfs/toolchain/[BuildArch]. You can change this behavior"
     echo "by setting the TOOLCHAIN_DIR environment variable"
     echo.
-    echo "By default, the NDK will be downloaded into the cross/android-rootfs/android-ndk-r13b directory. If you already have an NDK installation,"
+    echo "By default, the NDK will be downloaded into the cross/android-rootfs/android-ndk-$__NDK_Version directory. If you already have an NDK installation,"
     echo "you can set the NDK_DIR environment variable to have this script use that installation of the NDK."
     exit 1
 }
 
 __ApiLevel=21 # The minimum platform for arm64 is API level 21
 __BuildArch=arm64
 __AndroidArch=aarch64
+__AndroidToolchain=aarch64-linux-android
 
 for i in "$@"
     do
@@ -32,6 +34,12 @@ for i in "$@"
         arm64)
             __BuildArch=arm64
             __AndroidArch=aarch64
+            __AndroidToolchain=arm-linux-androideabi
+            ;;
+        arm)
+            __BuildArch=arm
+            __AndroidArch=arm
+            __AndroidToolchain=arm-linux-androideabi
             ;;
         *[0-9])
             __ApiLevel=$i
@@ -46,7 +54,7 @@ done
 __CrossDir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 __Android_Cross_Dir="$__CrossDir/android-rootfs"
-__NDK_Dir="$__Android_Cross_Dir/android-ndk-r13b"
+__NDK_Dir="$__Android_Cross_Dir/android-ndk-$__NDK_Version"
 __libunwind_Dir="$__Android_Cross_Dir/libunwind"
 __ToolchainDir="$__Android_Cross_Dir/toolchain/$__BuildArch"
 
@@ -67,8 +75,8 @@ echo "Target Toolchain location: $__ToolchainDir"
 if [ ! -d $__NDK_Dir ]; then
     echo Downloading the NDK into $__NDK_Dir
     mkdir -p $__NDK_Dir
-    wget -nv -nc --show-progress https://dl.google.com/android/repository/android-ndk-r13b-linux-x86_64.zip -O $__Android_Cross_Dir/android-ndk-r13b-linux-x86_64.zip
-    unzip -q $__Android_Cross_Dir/android-ndk-r13b-linux-x86_64.zip -d $__Android_Cross_Dir
+    wget -nv -nc --show-progress https://dl.google.com/android/repository/android-ndk-$__NDK_Version-linux-x86_64.zip -O $__Android_Cross_Dir/android-ndk-$__NDK_Version-linux-x86_64.zip
+    unzip -q $__Android_Cross_Dir/android-ndk-$__NDK_Version-linux-x86_64.zip -d $__Android_Cross_Dir
 fi
 
 # Create the RootFS for both arm64 as well as aarch
@@ -83,10 +91,10 @@ rm -rf $__Android_Cross_Dir/tmp
 
 mkdir -p $__Android_Cross_Dir/deb/
 mkdir -p $__Android_Cross_Dir/tmp/$arch/
-wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/libcurl-dev_7.52.1_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/libcurl-dev_7.52.1_$__AndroidArch.deb
-wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/libcurl_7.52.1_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/libcurl_7.52.1_$__AndroidArch.deb
-wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/krb5-dev_1.15_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/krb5-dev_1.15_$__AndroidArch.deb
-wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/krb5_1.15_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/krb5_1.15_$__AndroidArch.deb
+wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/libcurl-dev_7.53.1_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/libcurl-dev_7.52.1_$__AndroidArch.deb
+wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/libcurl_7.53.1_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/libcurl_7.52.1_$__AndroidArch.deb
+wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/krb5-dev_1.15.1_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/krb5-dev_1.15_$__AndroidArch.deb
+wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/krb5_1.15.1_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/krb5_1.15_$__AndroidArch.deb
 wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/openssl-dev_1.0.2k_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/openssl-dev_1.0.2k_$__AndroidArch.deb
 wget -nv -nc http://termux.net/dists/stable/main/binary-$__AndroidArch/openssl_1.0.2k_$__AndroidArch.deb -O $__Android_Cross_Dir/deb/openssl_1.0.2k_$__AndroidArch.deb
 
@@ -105,4 +113,4 @@ cp -R $__Android_Cross_Dir/tmp/$__AndroidArch/data/data/com.termux/files/usr/* $
 wget -nv -nc https://raw.githubusercontent.com/qnnnnez/android-ifaddrs/master/include/ifaddrs_single.h -O $__ToolchainDir/sysroot/usr/include/ifaddrs.h
 
 echo Now run:
-echo CONFIG_DIR=\`realpath cross/android/arm64\` ROOTFS_DIR=\`realpath $__ToolchainDir/sysroot\` ./build-native.sh -debug -buildArch=arm64 -- verbose cross
+echo CONFIG_DIR=\`realpath cross/android/$__BuildArch\` ROOTFS_DIR=\`realpath $__ToolchainDir/sysroot\` ./build-native.sh -debug -buildArch=$__BuildArch -- verbose cross

src/Native/Unix/CMakeLists.txt

@@ -52,6 +52,10 @@ elseif (CMAKE_SYSTEM_PROCESSOR STREQUAL armv7l)
   endif ()
     add_compile_options(-mthumb)
     add_compile_options(-mfpu=vfpv3)
+elseif (CMAKE_SYSTEM_PROCESSOR STREQUAL arm)
+    add_definitions(-DBIT32=1)
+    add_definitions(-D_ARM_)
+    add_definitions(-D_FILE_OFFSET_BITS=64)
 endif ()
 
 string(TOUPPER ${CMAKE_BUILD_TYPE} UPPERCASE_CMAKE_BUILD_TYPE)
@@ -151,7 +155,7 @@ if (NOT WIN32)
     else (CMAKE_SYSTEM_NAME STREQUAL Darwin)
         # Ensure that objcopy is present
         if(DEFINED ENV{CROSSCOMPILE})
-            if(CMAKE_SYSTEM_PROCESSOR STREQUAL armv7l OR CMAKE_SYSTEM_PROCESSOR STREQUAL aarch64 OR CMAKE_SYSTEM_PROCESSOR STREQUAL i686)
+            if(CMAKE_SYSTEM_PROCESSOR STREQUAL armv7l OR CMAKE_SYSTEM_PROCESSOR STREQUAL aarch64 OR CMAKE_SYSTEM_PROCESSOR STREQUAL i686 OR CMAKE_SYSTEM_PROCESSOR STREQUAL arm)
                 find_program(OBJCOPY ${TOOLCHAIN}-objcopy)
             else()
                 message(FATAL_ERROR "Only AMD64, X86, ARM64 and ARM are supported")