diff --git a/eng/Subsets.props b/eng/Subsets.props
index 43843ea213934..631bd533723cf 100644
--- a/eng/Subsets.props
+++ b/eng/Subsets.props
@@ -54,7 +54,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <DefaultCoreClrSubsets>clr.runtime+clr.jit+clr.alljits+linuxdac+clr.corelib+clr.nativecorelib+clr.tools+clr.packages</DefaultCoreClrSubsets>
+    <DefaultCoreClrSubsets>clr.runtime+clr.jit+clr.alljits+linuxdac+clr.corelib+clr.tools+clr.nativecorelib+clr.packages</DefaultCoreClrSubsets>
 
     <DefaultMonoSubsets Condition="'$(MonoEnableLLVM)' == 'true' and '$(MonoLLVMDir)' == ''">mono.llvm+</DefaultMonoSubsets>
     <DefaultMonoSubsets Condition="'$(MonoAOTEnableLLVM)' == 'true' and '$(MonoAOTLLVMDir)' == ''">mono.llvm+</DefaultMonoSubsets>
@@ -191,17 +191,19 @@
     <ProjectToBuild Include="$(CoreClrProjectRoot)src\.nuget\Microsoft.CrossOsDiag.Private.CoreCLR\Microsoft.CrossOsDiag.Private.CoreCLR.proj" Category="clr" />
   </ItemGroup>
 
-  <ItemGroup Condition="$(_subset.Contains('+clr.nativecorelib+'))">
-    <ProjectToBuild Include="$(CoreClrProjectRoot)crossgen-corelib.proj" Category="clr" />
-  </ItemGroup>
-
   <ItemGroup Condition="$(_subset.Contains('+clr.tools+'))">
     <ProjectToBuild Include="$(CoreClrProjectRoot)src\tools\runincontext\runincontext.csproj;
                              $(CoreClrProjectRoot)src\tools\r2rdump\R2RDump.csproj;
                              $(CoreClrProjectRoot)src\tools\dotnet-pgo\dotnet-pgo.csproj;
-                             $(CoreClrProjectRoot)src\tools\r2rtest\R2RTest.csproj" Category="clr" BuildInParallel="true" />
-    <ProjectToBuild Include="$(CoreClrProjectRoot)src\tools\aot\crossgen2\crossgen2.csproj" Category="clr" />
-    <ProjectToBuild Include="$(CoreClrProjectRoot)src\tools\aot\ILCompiler.TypeSystem.ReadyToRun.Tests\ILCompiler.TypeSystem.ReadyToRun.Tests.csproj" Test="true" Category="clr" Condition="'$(__DistroRid)' != 'linux-musl-x64'"/>
+                             $(CoreClrProjectRoot)src\tools\r2rtest\R2RTest.csproj;
+                             $(CoreClrProjectRoot)src\tools\aot\crossgen2\crossgen2.csproj" Category="clr" />
+
+    <ProjectToBuild Include="$(CoreClrProjectRoot)src\tools\aot\ILCompiler.TypeSystem.ReadyToRun.Tests\ILCompiler.TypeSystem.ReadyToRun.Tests.csproj"
+      Test="true" Category="clr" Condition="'$(__DistroRid)' != 'linux-musl-x64'"/>
+  </ItemGroup>
+
+  <ItemGroup Condition="$(_subset.Contains('+clr.nativecorelib+'))">
+    <ProjectToBuild Include="$(CoreClrProjectRoot)crossgen-corelib.proj" Category="clr" />
   </ItemGroup>
 
   <ItemGroup Condition="$(_subset.Contains('+clr.packages+'))">
diff --git a/src/coreclr/crossgen-corelib.proj b/src/coreclr/crossgen-corelib.proj
index bf26cd259a8c5..6144cbfaf08ee 100644
--- a/src/coreclr/crossgen-corelib.proj
+++ b/src/coreclr/crossgen-corelib.proj
@@ -3,21 +3,101 @@
   <Import Project="Directory.Build.targets" />
 
   <Target Name="Build">
-    <ItemGroup>
-      <_CoreClrBuildArg Condition="'$(TargetArchitecture)' != ''" Include="-$(TargetArchitecture)" />
-      <_CoreClrBuildArg Include="-$(Configuration.ToLower())" />
-      <_CoreClrBuildArg Condition="!$([MSBuild]::IsOsPlatform(Windows))" Include="-os $(TargetOS)" />
-      <_CoreClrBuildArg Condition="'$(CrossBuild)' == 'true'" Include="-cross" />
-      <_CoreClrBuildArg Condition="'$(PortableBuild)' != 'true'" Include="-portablebuild=false" />
-    </ItemGroup>
+    <PropertyGroup>
+      <!-- Default for using Crossgen2 when not set externally -->
+      <UseCrossgen2 Condition="'$(UseCrossgen2)' == ''">false</UseCrossgen2>
+
+      <OSPlatformConfig>$(TargetOS).$(TargetArchitecture).$(Configuration)</OSPlatformConfig>
+      <RootBinDir>$(RepoRoot)\artifacts</RootBinDir>
+      <LogsDir>$(RootBinDir)\log</LogsDir>
+      <BinDir>$(RootBinDir)\bin\coreclr\$(OSPlatformConfig)</BinDir>
+      <IntermediatesDir>$(RootBinDir)\obj\coreclr\$(OSPlatformConfig)</IntermediatesDir>
+      <CrossGenCoreLibLog>$(LogsDir)\CrossgenCoreLib_$(TargetOS)__$(TargetArchitecture)__$(Configuration).log</CrossGenCoreLibLog>
+      <ExeExtension Condition="'$(OS)' == 'Windows_NT'">.exe</ExeExtension>
+      <DotNetCli>$(RepoRoot)/dotnet.sh</DotNetCli>
+      <DotNetCli Condition="'$(OS)' == 'Windows_NT'">$(RepoRoot)\dotnet.cmd</DotNetCli>
+
+      <CoreLibAssemblyName>System.Private.CoreLib</CoreLibAssemblyName>
+      <CoreLibInputPath>$(BinDir)\IL\$(CoreLibAssemblyName).dll</CoreLibInputPath>
+      <CoreLibOutputPath>$(BinDir)\$(CoreLibAssemblyName).dll</CoreLibOutputPath>
+
+      <CrossDir></CrossDir>
+      <CrossDir Condition="'$(TargetArchitecture)' == 'arm' or '$(TargetArchitecture)' == 'arm64'">x64</CrossDir>
+      <CrossDir Condition="'$(TargetArchitecture)' == 'arm' and '$(UseCrossgen2)' != 'true' and '$(OS)' == 'Windows_NT'">x86</CrossDir>
+      <CrossDir Condition="'$(TargetArchitecture)' == 'x86' and '$(BuildArchitecture)' != '$(TargetArchitecture)' and '$(UseCrossgen2)' == 'true'">$(BuildArchitecture)</CrossDir>
+
+      <BuildDll>true</BuildDll>
+      <BuildDll Condition="'$(CrossBuild)' == 'true' and '$(CrossDir)' == ''">false</BuildDll>
+
+      <BuildPdb>false</BuildPdb>
+      <BuildPdb Condition="$(BuildDll) and '$(OS)' == 'Windows_NT' and '$(TargetOS)' == 'Windows'">true</BuildPdb>
+
+      <BuildPerfMap>false</BuildPerfMap>
+      <BuildPerfMap Condition="$(BuildDll) and '$(TargetOS)' == 'Linux'">true</BuildPerfMap>
+
+      <CrossGen1Cmd>$(BinDir)\$(CrossDir)\crossgen$(ExeExtension)</CrossGen1Cmd>
+      <CrossGen1Cmd>$(CrossGen1Cmd) /nologo</CrossGen1Cmd>
+      <CrossGen1Cmd>$(CrossGen1Cmd) <!-- IbcTuning --></CrossGen1Cmd>
+      <CrossGen1Cmd>$(CrossGen1Cmd) /Platform_Assemblies_Paths "$(BinDir)\IL"</CrossGen1Cmd>
+    </PropertyGroup>
+
+    <MakeDir
+      Directories="$(BinDir);$(IntermediatesDir);$(LogsDir)" />
+
+    <Message Importance="High"
+      Text="Generating native image of System.Private.CoreLib for $(OSPlatformConfig). Logging to $(CrossGenCoreLibLog)" />
 
     <PropertyGroup>
-      <_CoreClrBuildScript Condition="$([MSBuild]::IsOsPlatform(Windows))">crossgen-corelib.cmd</_CoreClrBuildScript>
-      <_CoreClrBuildScript Condition="!$([MSBuild]::IsOsPlatform(Windows))">crossgen-corelib.sh</_CoreClrBuildScript>
+      <CrossGenDllCmd>$(DotNetCli) $(BinDir)\$(CrossDir)\crossgen2\crossgen2.dll</CrossGenDllCmd>
+      <CrossGenDllCmd>$(CrossGenDllCmd) -o:$(CoreLibOutputPath)</CrossGenDllCmd>
+      <CrossGenDllCmd>$(CrossGenDllCmd) -r:$(BinDir)\IL\*.dll</CrossGenDllCmd>
+      <CrossGenDllCmd>$(CrossGenDllCmd) --targetarch:$(TargetArchitecture)</CrossGenDllCmd>
+      <CrossGenDllCmd>$(CrossGenDllCmd) -O</CrossGenDllCmd>
+      <CrossGenDllCmd>$(CrossGenDllCmd) $(CoreLibInputPath)</CrossGenDllCmd>
     </PropertyGroup>
 
-    <!-- Use IgnoreStandardErrorWarningFormat because Arcade sets WarnAsError and there's an existing warning in the native build. -->
-    <Exec Command="&quot;$(MSBuildThisFileDirectory)$(_CoreClrBuildScript)&quot; @(_CoreClrBuildArg->'%(Identity)',' ')" />
+    <PropertyGroup Condition="'$(UseCrossgen2)' != 'true'">
+      <CrossGenDllCmd>$(CrossGen1Cmd) /out "$(CoreLibOutputPath)"</CrossGenDllCmd> 
+      <CrossGenDllCmd>$(CrossGenDllCmd) "$(CoreLibInputPath)"</CrossGenDllCmd>
+    </PropertyGroup>
+
+    <!-- For now we're using Crossgen1 for generating the perf map as Crossgen2 doesn't yet implement it: -->
+    <!-- https://github.com/dotnet/runtime/issues/44123 -->
+    <PropertyGroup Condition="$(BuildPerfMap)">
+      <CrossGenPerfMapCmd>$(CrossGen1Cmd) /CreatePerfMap "$(BinDir)"</CrossGenPerfMapCmd>
+      <CrossGenPerfMapCmd>$(CrossGenPerfMapCmd) "$(CoreLibOutputPath)"</CrossGenPerfMapCmd>
+    </PropertyGroup>
+    
+    <PropertyGroup Condition="$(BuildPdb)">
+      <CrossGenPdbCmd>$(DotNetCli) $(BinDir)\r2rdump\r2rdump.dll</CrossGenPdbCmd>
+      <CrossGenPdbCmd>$(CrossGenPdbCmd) --create-pdb</CrossGenPdbCmd>
+      <CrossGenPdbCmd>$(CrossGenPdbCmd) --pdb-path:$(BinDir)\PDB</CrossGenPdbCmd>
+      <CrossGenPdbCmd>$(CrossGenPdbCmd) --in:$(CoreLibOutputPath)</CrossGenPdbCmd>
+    </PropertyGroup>
+    
+    <PropertyGroup Condition="$(BuildPdb) and '$(UseCrossgen2)' != 'true'">
+      <VsSetupCmd>call $(RepoRoot)\src\coreclr\setup_vs_tools.cmd &amp;&amp;</VsSetupCmd>
+
+      <CrossGenPdbCmd>$(VsSetupCmd) $(CrossGen1Cmd) /CreatePdb "$(BinDir)\PDB"</CrossGenPdbCmd>
+      <CrossGenPdbCmd>$(CrossGenPdbCmd) "$(CoreLibOutputPath)"</CrossGenPdbCmd>
+    </PropertyGroup>
+    
+    <Message Condition="$(BuildDll)" Importance="High" Text="$(CrossGenDllCmd)" />
+    
+    <Exec Condition="$(BuildDll)" Command="$(CrossGenDllCmd)" />
+
+    <Message Condition="$(BuildPdb)" Importance="High" Text="$(CrossGenPdbCmd)" />
+
+    <Exec Condition="$(BuildPdb)" Command="$(CrossGenPdbCmd)" />
+
+    <Message Condition="$(BuildPerfMap)" Importance="High" Text="$(CrossGenPerfMapCmd)" />
+
+    <Exec Condition="$(BuildPerfMap)" Command="$(CrossGenPerfMapCmd)" />
+
+    <Copy Condition="!$(BuildDll)" SourceFiles="$(CoreLibInputPath)" DestinationFiles="$(CoreLibOutputPath)" UseHardlinksIfPossible="true" />
+
+    <Message Importance="High" Text="Crossgenning of System.Private.CoreLib succeeded.  Finished at $(TIME)" />
+    <Message Importance="High" Text="Product binaries are available at $(BinDir)" />
   </Target>
 
   <Target Name="Restore" />
diff --git a/src/coreclr/src/tools/r2rdump/R2RDump.csproj b/src/coreclr/src/tools/r2rdump/R2RDump.csproj
index 0b575b257ff2a..46b8e0c6eaa50 100644
--- a/src/coreclr/src/tools/r2rdump/R2RDump.csproj
+++ b/src/coreclr/src/tools/r2rdump/R2RDump.csproj
@@ -4,7 +4,8 @@
     <AssemblyVersion>1.0.0.0</AssemblyVersion>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <OutputType>Exe</OutputType>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <Platforms>x64;x86;arm64;arm</Platforms>
+    <PlatformTarget>AnyCPU</PlatformTarget>
     <AssemblyKey>Open</AssemblyKey>
     <IsDotNetFrameworkProductAssembly>true</IsDotNetFrameworkProductAssembly>
     <TargetFramework>$(NetCoreAppToolCurrent)</TargetFramework>
@@ -12,7 +13,6 @@
     <NoWarn>8002,NU1701</NoWarn>
     <RuntimeIdentifiers>win-x64;win-x86</RuntimeIdentifiers>
     <OutputPath>$(RuntimeBinDir)/R2RDump</OutputPath>
-    <Platforms>AnyCPU;x64</Platforms>
   </PropertyGroup>
 
   <Import Project="$(RepositoryEngineeringDir)DiaSymReaderNative.targets" />