diff --git a/eng/common/build.ps1 b/eng/common/build.ps1
index d7e3799ebd9..67046a43f8c 100644
--- a/eng/common/build.ps1
+++ b/eng/common/build.ps1
@@ -1,6 +1,7 @@
 [CmdletBinding(PositionalBinding=$false)]
 Param(
   [string][Alias('c')]$configuration = "Debug",
+  [string]$platform = $null,
   [string] $projects,
   [string][Alias('v')]$verbosity = "minimal",
   [string] $msbuildEngine = $null,
@@ -29,6 +30,7 @@ Param(
 function Print-Usage() {
     Write-Host "Common settings:"
     Write-Host "  -configuration <value>  Build configuration: 'Debug' or 'Release' (short: -c)"
+    Write-Host "  -platform <value>       Platform configuration: 'x86', 'x64' or any valid Platform value to pass to msbuild"
     Write-Host "  -verbosity <value>      Msbuild verbosity: q[uiet], m[inimal], n[ormal], d[etailed], and diag[nostic] (short: -v)"
     Write-Host "  -binaryLog              Output binary log (short: -bl)"
     Write-Host "  -help                   Print help and exit"
@@ -77,6 +79,7 @@ function Build {
   InitializeCustomToolset
 
   $bl = if ($binaryLog) { "/bl:" + (Join-Path $LogDir "Build.binlog") } else { "" }
+  $platformArg = if ($platform) { "/p:Platform=$platform" } else { "" }
 
   if ($projects) {
     # Re-assign properties to a new variable because PowerShell doesn't let us append properties directly for unclear reasons.
@@ -88,6 +91,7 @@ function Build {
 
   MSBuild $toolsetBuildProj `
     $bl `
+    $platformArg `
     /p:Configuration=$configuration `
     /p:RepoRoot=$RepoRoot `
     /p:Restore=$restore `
diff --git a/eng/common/dotnet-install.ps1 b/eng/common/dotnet-install.ps1
index 5987943fd6f..0b629b8301a 100644
--- a/eng/common/dotnet-install.ps1
+++ b/eng/common/dotnet-install.ps1
@@ -8,9 +8,14 @@ Param(
 
 . $PSScriptRoot\tools.ps1
 
+$dotnetRoot = Join-Path $RepoRoot ".dotnet"
+
+$installdir = $dotnetRoot
 try {
-  $dotnetRoot = Join-Path $RepoRoot ".dotnet"
-  InstallDotNet $dotnetRoot $version $architecture $runtime $true
+    if ($architecture -and $architecture.Trim() -eq "x86") {
+        $installdir = Join-Path $installdir "x86"
+    }
+   InstallDotNet $installdir $version $architecture $runtime $true
 } 
 catch {
   Write-Host $_
@@ -19,4 +24,4 @@ catch {
   ExitWithExitCode 1
 }
 
-ExitWithExitCode 0
\ No newline at end of file
+ExitWithExitCode 0
diff --git a/src/Microsoft.DotNet.Arcade.Sdk/src/InstallDotNetCore.cs b/src/Microsoft.DotNet.Arcade.Sdk/src/InstallDotNetCore.cs
index b49030a58b1..4f3cd294623 100644
--- a/src/Microsoft.DotNet.Arcade.Sdk/src/InstallDotNetCore.cs
+++ b/src/Microsoft.DotNet.Arcade.Sdk/src/InstallDotNetCore.cs
@@ -28,6 +28,8 @@ public class InstallDotNetCore : Task
         public string DotNetInstallScript { get; set; }
         [Required]
         public string GlobalJsonPath { get; set; }
+        [Required]
+        public string Platform { get; set; }
 
         public override bool Execute()
         {
@@ -55,7 +57,14 @@ public override bool Execute()
                         foreach (var runtime in dotnetLocalElement.EnumerateObject())
                         {
                             var items = GetItemsFromJsonElementArray(runtime, out string runtimeName);
-                            runtimeItems.Add(runtimeName, items);
+                            if (runtimeItems.ContainsKey(runtimeName))
+                            {
+                                runtimeItems[runtimeName] = runtimeItems[runtimeName].Concat(items);
+                            }
+                            else
+                            {
+                                runtimeItems.Add(runtimeName, items);
+                            }
                         }
                         if (runtimeItems.Count > 0)
                         {
@@ -96,16 +105,25 @@ public override bool Execute()
                                     if(version != null)
                                     {
                                         string arguments = $"-runtime \"{runtimeItem.Key}\" -version \"{version.ToNormalizedString()}\"";
+
                                         string architecture = item.Value;
                                         if (!string.IsNullOrWhiteSpace(architecture))
                                         {
                                             arguments += $" -architecture {architecture}";
                                         }
-                                        else if (RuntimeInformation.OSArchitecture == Architecture.X86 ||
-                                                 RuntimeInformation.OSArchitecture == Architecture.X64)
+                                        else
                                         {
-                                            arguments += " -architecture x64";
+                                            if (!string.IsNullOrWhiteSpace(Platform) && !string.Equals(Platform, "AnyCpu", StringComparison.OrdinalIgnoreCase))
+                                            {
+                                                arguments += $" -architecture {Platform}";
+                                            }
+                                            else if (RuntimeInformation.OSArchitecture == Architecture.X86 ||
+                                                     RuntimeInformation.OSArchitecture == Architecture.X64)
+                                            {
+                                                arguments += " -architecture x64";
+                                            }
                                         }
+
                                         Log.LogMessage(MessageImportance.Low, $"Executing: {DotNetInstallScript} {arguments}");
                                         var process = Process.Start(new ProcessStartInfo()
                                         {
diff --git a/src/Microsoft.DotNet.Arcade.Sdk/tools/InstallDotNetCore.targets b/src/Microsoft.DotNet.Arcade.Sdk/tools/InstallDotNetCore.targets
index e1a2abfb15d..444a002de7e 100644
--- a/src/Microsoft.DotNet.Arcade.Sdk/tools/InstallDotNetCore.targets
+++ b/src/Microsoft.DotNet.Arcade.Sdk/tools/InstallDotNetCore.targets
@@ -15,7 +15,8 @@
     <InstallDotNetCore
       VersionsPropsPath="$(RepoRoot)eng\Versions.props"
       GlobalJsonPath="$(RepoRoot)global.json"
-      DotNetInstallScript="$(_DotNetInstallScript)"/>
+      DotNetInstallScript="$(_DotNetInstallScript)"
+      Platform="$(Platform)"/>
   </Target>
 
 </Project>
diff --git a/src/Microsoft.DotNet.Arcade.Sdk/tools/XUnit/XUnit.targets b/src/Microsoft.DotNet.Arcade.Sdk/tools/XUnit/XUnit.targets
index b0f98d65d17..241ab2ea739 100644
--- a/src/Microsoft.DotNet.Arcade.Sdk/tools/XUnit/XUnit.targets
+++ b/src/Microsoft.DotNet.Arcade.Sdk/tools/XUnit/XUnit.targets
@@ -47,7 +47,10 @@
       <_TargetDir>$([System.IO.Path]::GetDirectoryName('$(_TestAssembly)'))\</_TargetDir>
       <_CoreRuntimeConfigPath>$(_TargetDir)$(_TargetFileNameNoExt).runtimeconfig.json</_CoreRuntimeConfigPath>
       <_CoreDepsPath>$(_TargetDir)$(_TargetFileNameNoExt).deps.json</_CoreDepsPath>
-      <_TestRunner>$(DotNetTool)</_TestRunner>
+      
+      <_TestRunner Condition="'%(TestToRun.Architecture)'=='x86' And Exists('$(DotNetRoot)x86\dotnet.exe')">$(DotNetRoot)x86\dotnet.exe</_TestRunner>
+      <_TestRunner Condition="'$(_TestRunner)'==''">$(DotNetTool)</_TestRunner>
+      
       <_TestRunnerArgs>exec --depsfile "$(_CoreDepsPath)" --runtimeconfig "$(_CoreRuntimeConfigPath)" $(TestRuntimeAdditionalArguments) "$(NuGetPackageRoot)xunit.runner.console/$(XUnitVersion)/tools/$(_TestRunnerTargetFramework)/xunit.console.dll" "$(_TestAssembly)" -noautoreporters -xml "%(TestToRun.ResultsXmlPath)" -html "%(TestToRun.ResultsHtmlPath)" $(_TestRunnerAdditionalArguments)</_TestRunnerArgs>
     </PropertyGroup>