dotnet · simonrozsival · May 19, 2026 · Apr 29, 2026 · Apr 29, 2026 · Apr 30, 2026
diff --git a/eng/Subsets.props b/eng/Subsets.props
@@ -29,8 +29,7 @@
     <!-- Determine if the CoreCLR runtime can build/run for the specified target. -->
     <_CoreCLRSupportedOS Condition="'$(TargetsMobile)' != 'true' and '$(TargetsLinuxBionic)' != 'true'">true</_CoreCLRSupportedOS>
 
-    <!-- Android 32-bit builds blocked by https://github.com/dotnet/runtime/issues/111665 -->
-    <_CoreCLRSupportedOS Condition="'$(TargetsAndroid)' == 'true' and '$(TargetArchitecture)' != 'arm' and '$(TargetArchitecture)' != 'x86'">true</_CoreCLRSupportedOS>
+    <_CoreCLRSupportedOS Condition="'$(TargetsAndroid)' == 'true' and '$(TargetArchitecture)' != 'x86'">true</_CoreCLRSupportedOS>
     <_CoreCLRSupportedOS Condition="'$(TargetsBrowser)' == 'true'">true</_CoreCLRSupportedOS>
     <_CoreCLRSupportedOS Condition="'$(TargetsAppleMobile)' == 'true'">true</_CoreCLRSupportedOS>
 

diff --git a/eng/native/configureplatform.cmake b/eng/native/configureplatform.cmake
@@ -373,6 +373,10 @@ if(CLR_CMAKE_TARGET_OS STREQUAL android)
     set(CLR_CMAKE_TARGET_ANDROID 1)
 endif(CLR_CMAKE_TARGET_OS STREQUAL android)
 
+if(CLR_CMAKE_TARGET_ANDROID AND CLR_CMAKE_TARGET_ARCH_ARM)
+    set(ARM_SOFTFP 1)
+endif()
+
 if(CLR_CMAKE_TARGET_OS STREQUAL darwin)
     set(CLR_CMAKE_TARGET_UNIX 1)
     set(CLR_CMAKE_TARGET_APPLE 1)

diff --git a/eng/pipelines/coreclr/templates/helix-queues-setup.yml b/eng/pipelines/coreclr/templates/helix-queues-setup.yml
@@ -46,6 +46,13 @@ jobs:
       - ${{ if eq(variables['System.TeamProject'], 'internal') }}:
         - OSX.15.Amd64
 
+    # Android arm
+    - ${{ if in(parameters.platform, 'android_arm') }}:
+      - ${{ if eq(variables['System.TeamProject'], 'public') }}:
+        - Windows.11.Amd64.Android.Open
+      - ${{ if eq(variables['System.TeamProject'], 'internal') }}:
+        - Windows.11.Amd64.Android
+
     # Android arm64
     - ${{ if in(parameters.platform, 'android_arm64') }}:
       - ${{ if eq(variables['System.TeamProject'], 'public') }}:

diff --git a/eng/pipelines/extra-platforms/runtime-extra-platforms-android.yml b/eng/pipelines/extra-platforms/runtime-extra-platforms-android.yml
@@ -95,6 +95,7 @@ jobs:
     buildConfig: Release
     runtimeFlavor: coreclr
     platforms:
+    - android_arm
     - android_arm64
     variables:
       # map dependencies variables to local variables

diff --git a/eng/pipelines/runtime.yml b/eng/pipelines/runtime.yml
@@ -1099,7 +1099,7 @@ extends:
                     eq(variables['isRollingBuild'], true))
 
       #
-      # Android arm64 devices and x64 emulators
+      # Android arm/arm64 devices and x64 emulators
       # Build the whole product using CoreCLR and run functional tests
       #
       - template: /eng/pipelines/common/platform-matrix.yml
@@ -1109,6 +1109,7 @@ extends:
           buildConfig: Release
           runtimeFlavor: coreclr
           platforms:
+          - android_arm
           - android_x64
           - android_arm64
           variables:

diff --git a/eng/testing/tests.readytorun.targets b/eng/testing/tests.readytorun.targets
@@ -3,14 +3,12 @@
   <Target Name="ResolveReadyToRunCompilers">
     <PropertyGroup>
       <Crossgen2Path>$([MSBuild]::NormalizePath('$(Crossgen2InBuildDir)', 'crossgen2$(ExeSuffix)'))</Crossgen2Path>
-      <_CrossGenTargetOS Condition="'$(TargetsAndroid)' != 'true'">$(TargetOS)</_CrossGenTargetOS>
-      <_CrossGenTargetOS Condition="'$(TargetsAndroid)' == 'true'">linux</_CrossGenTargetOS>
     </PropertyGroup>
 
     <ItemGroup>
       <Crossgen2Tool Include="$(Crossgen2Path)"
                      TargetArch="$(TargetArchitecture)"
-                     TargetOS="$(_CrossGenTargetOS)"
+                     TargetOS="$(TargetOS)"
                      PerfmapFormatVersion="$(PublishReadyToRunPerfmapFormatVersion)"/>
     </ItemGroup>
   </Target>

diff --git a/src/coreclr/clrdefinitions.cmake b/src/coreclr/clrdefinitions.cmake
@@ -292,7 +292,8 @@ function(set_target_definitions_to_custom_os_and_arch)
     target_compile_definitions(${TARGETDETAILS_TARGET} PRIVATE TARGET_WASM32)
   endif()
 
-  if (TARGETDETAILS_ARCH STREQUAL "armel")
+  if (TARGETDETAILS_ARCH STREQUAL "armel" OR
+      (TARGETDETAILS_ARCH STREQUAL "arm" AND CLR_CMAKE_TARGET_ANDROID))
     target_compile_definitions(${TARGETDETAILS_TARGET} PRIVATE ARM_SOFTFP)
   endif()
 endfunction()
diff --git a/src/coreclr/crossgen-corelib.proj b/src/coreclr/crossgen-corelib.proj
@@ -150,9 +150,7 @@
       <CrossGenDllCmd>$(CrossGenDllCmd) --targetarch:$(TargetArchitecture)</CrossGenDllCmd>
       <CrossGenDllCmd Condition="'$(PublishReadyToRunContainerFormat)' != ''">$(CrossGenDllCmd) --obj-format:$(PublishReadyToRunContainerFormat)</CrossGenDllCmd>
       <CrossGenDllCmd Condition="'$(UseComposite)' == 'true'">$(CrossGenDllCmd) --composite</CrossGenDllCmd>
-      <CrossGenDllCmd Condition="'$(TargetsAndroid)' != 'true'">$(CrossGenDllCmd) --targetos:$(TargetOS)</CrossGenDllCmd>
-      <!-- Unless and until Android requires R2R specific customizations, we're just dealing with another linux -->
-      <CrossGenDllCmd Condition="'$(TargetsAndroid)' == 'true'">$(CrossGenDllCmd) --targetos:linux</CrossGenDllCmd>
+      <CrossGenDllCmd>$(CrossGenDllCmd) --targetos:$(TargetOS)</CrossGenDllCmd>
       <CrossGenDllCmd Condition="'$(UsingToolIbcOptimization)' != 'true' and '$(EnableNgenOptimization)' == 'true'">$(CrossGenDllCmd) -m:$(MergedMibcPath) --embed-pgo-data</CrossGenDllCmd>
       <CrossGenDllCmd>$(CrossGenDllCmd) -O</CrossGenDllCmd>
       <!-- Enable type and field layout verification to make it easier to catch when the crossgen2 type layout engine and the runtime disagree on layout conventions -->

@@ -84,6 +84,7 @@ public static TargetOS GetTargetOS(string token)
                 "tvos" => TargetOS.tvOS,
                 "browser" => TargetOS.Browser,
                 "wasi" => TargetOS.Wasi,
+                "android" => TargetOS.Android,
                 _ => throw new CommandLineException($"Target OS '{token}' is not supported")
             };
         }

diff --git a/src/coreclr/tools/Common/TypeSystem/Common/TargetDetails.cs b/src/coreclr/tools/Common/TypeSystem/Common/TargetDetails.cs
@@ -24,7 +24,8 @@ public enum TargetOS
         NetBSD,
         SunOS,
         Browser,
-        Wasi
+        Wasi,
+        Android
     }
 
     public enum TargetAbi

diff --git a/src/coreclr/tools/aot/crossgen2/Crossgen2RootCommand.cs b/src/coreclr/tools/aot/crossgen2/Crossgen2RootCommand.cs
@@ -309,7 +309,7 @@ public static void PrintExtendedHelp(ParseResult _)
             Console.WriteLine();
 
             string[] ValidArchitectures = ["arm", "armel", "arm64", "x86", "x64", "riscv64", "loongarch64", "wasm"];
-            string[] ValidOS = ["windows", "linux", "osx", "ios", "iossimulator", "maccatalyst", "browser"];
+            string[] ValidOS = ["windows", "linux", "android", "osx", "ios", "iossimulator", "maccatalyst", "browser"];
 
             Console.WriteLine(String.Format(SR.SwitchWithDefaultHelp, "--targetos", String.Join("', '", ValidOS), Helpers.GetTargetOS(null).ToString().ToLowerInvariant()));
             Console.WriteLine();

diff --git a/src/coreclr/tools/aot/crossgen2/Program.cs b/src/coreclr/tools/aot/crossgen2/Program.cs
@@ -85,6 +85,16 @@ public int Run()
 
             TargetArchitecture targetArchitecture = Get(_command.TargetArchitecture);
             TargetOS targetOS = Get(_command.TargetOS);
+            TargetAbi targetAbi = Crossgen2RootCommand.IsArmel ? TargetAbi.NativeAotArmel : TargetAbi.NativeAot;
+
+            if (targetOS == TargetOS.Android)
+            {
+                // android-arm maps to Android's armeabi-v7a ABI, which uses softfp call boundaries.
+                // The rest of Crossgen2's Android behavior matches Linux/Bionic.
+                targetOS = TargetOS.Linux;
+                targetAbi = targetArchitecture == TargetArchitecture.ARM ? TargetAbi.NativeAotArmel : TargetAbi.NativeAot;
+            }
+
             bool allowOptimistic = _command.OptimizationMode != OptimizationMode.PreferSize;
 
             if (targetOS is TargetOS.iOS or TargetOS.tvOS or TargetOS.iOSSimulator or TargetOS.tvOSSimulator or TargetOS.MacCatalyst or TargetOS.Browser)
@@ -100,7 +110,7 @@ public int Run()
                 allowOptimistic: allowOptimistic,
                 isReadyToRun: true);
             SharedGenericsMode genericsMode = SharedGenericsMode.CanonicalReferenceTypes;
-            var targetDetails = new TargetDetails(targetArchitecture, targetOS, Crossgen2RootCommand.IsArmel ? TargetAbi.NativeAotArmel : TargetAbi.NativeAot, instructionSetSupport.GetVectorTSimdVector());
+            var targetDetails = new TargetDetails(targetArchitecture, targetOS, targetAbi, instructionSetSupport.GetVectorTSimdVector());
 
             ConfigureImageBase(targetDetails);
 

diff --git a/src/installer/pkg/sfx/Microsoft.NETCore.App/Microsoft.NETCore.App.Runtime.CoreCLR.sfxproj b/src/installer/pkg/sfx/Microsoft.NETCore.App/Microsoft.NETCore.App.Runtime.CoreCLR.sfxproj
@@ -48,14 +48,12 @@
   <Target Name="ResolveReadyToRunCompilers" DependsOnTargets="ResolveRuntimeFilesFromLocalBuild">
     <PropertyGroup>
       <Crossgen2Path>$([MSBuild]::NormalizePath('$(Crossgen2InBuildDir)', 'crossgen2$(ExeSuffix)'))</Crossgen2Path>
-      <_CrossGenTargetOS Condition="'$(TargetsAndroid)' != 'true'">$(TargetOS)</_CrossGenTargetOS>
-      <_CrossGenTargetOS Condition="'$(TargetsAndroid)' == 'true'">linux</_CrossGenTargetOS>
     </PropertyGroup>
 
     <ItemGroup>
       <Crossgen2Tool Include="$(Crossgen2Path)"
                      TargetArch="$(TargetArchitecture)"
-                     TargetOS="$(_CrossGenTargetOS)"
+                     TargetOS="$(TargetOS)"
                      PerfmapFormatVersion="$(PublishReadyToRunPerfmapFormatVersion)"/>
     </ItemGroup>
 

@@ -33,7 +33,7 @@
     <ItemGroup>
       <Crossgen2Tool Include="$(Crossgen2Path)"
                      TargetArch="$(TargetArchitecture)"
-                     TargetOS="linux"
+                     TargetOS="$(TargetOS)"
                      PerfmapFormatVersion="$(PublishReadyToRunPerfmapFormatVersion)"/>
     </ItemGroup>
   </Target>

diff --git a/src/tasks/Crossgen2Tasks/ResolveReadyToRunCompilers.cs b/src/tasks/Crossgen2Tasks/ResolveReadyToRunCompilers.cs
@@ -210,11 +210,12 @@ private bool GetCrossgen2TargetOS(out string targetOS)
             string portablePlatform = NuGetUtils.GetBestMatchingRid(
                     runtimeGraph,
                     _targetRuntimeIdentifier,
-                    new[] { "linux", "osx", "win", "freebsd", "illumos" },
+                    new[] { "android", "linux", "osx", "win", "freebsd", "illumos" },
                     out _);
 
             targetOS = portablePlatform switch
             {
+                "android" => "android",
                 "linux" => "linux",
                 "osx" => "osx",
                 "win" => "windows",
-Original file line number
+Diff line change
@@ Expand Up / @@ -24,7 +24,8 @@ public enum TargetOS @@
             NetBSD,
             SunOS,
             Browser,
-            Wasi
+            Wasi,
+            Android
         }
         public enum TargetAbi
@@ Expand Down @@