diff --git a/eng/SourceBuild.Version.Details.xml b/eng/SourceBuild.Version.Details.xml
index 52faed3afd7a..db9bdda4fe12 100644
--- a/eng/SourceBuild.Version.Details.xml
+++ b/eng/SourceBuild.Version.Details.xml
@@ -1,6 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Dependencies>
   <ProductDependencies>
+    <Dependency Name="VS.Redist.Common.AspNetCore.SharedFramework.x64.6.0" Version="6.0.0-preview.6.21355.2" CoherentParentDependency="Microsoft.NET.Sdk">
+      <Uri>https://github.com/dotnet/aspnetcore</Uri>
+      <Sha>71dd6b0c87d7619668a40876d084d93db57eab41</Sha>
+      <SourceBuild RepoName="aspnetcore" ManagedOnly="true" />
+    </Dependency>
     <Dependency Name="Microsoft.DotNet.Cli.CommandLine" Version="1.0.0-preview.21310.2">
       <Uri>https://github.com/dotnet/clicommandlineparser</Uri>
       <Sha>3198bf5660cad3dab85f5475bf1fda9688146e3f</Sha>
diff --git a/src/SourceBuild/tarball/content/TemporaryBootstrapPackageVersions.props b/src/SourceBuild/tarball/content/TemporaryBootstrapPackageVersions.props
index 235106b6b3c5..c2b56598ae7d 100755
--- a/src/SourceBuild/tarball/content/TemporaryBootstrapPackageVersions.props
+++ b/src/SourceBuild/tarball/content/TemporaryBootstrapPackageVersions.props
@@ -9,6 +9,7 @@
     file can be removed.
   -->
   <PropertyGroup>
+    <MicrosoftExtensionsDependencyModelVersion>6.0.0-preview.6.21352.12</MicrosoftExtensionsDependencyModelVersion>
     <MicrosoftNETCorePlatformsPackageVersion>3.1.0</MicrosoftNETCorePlatformsPackageVersion>
     <MicrosoftNETCorePlatformsVersion>3.1.0</MicrosoftNETCorePlatformsVersion>
     <SystemCollectionsImmutablePackageVersion>6.0.0-preview.6.21352.12</SystemCollectionsImmutablePackageVersion>
diff --git a/src/SourceBuild/tarball/content/patches/aspnetcore/0001-Run-GenerateFiles-during-source-build.patch b/src/SourceBuild/tarball/content/patches/aspnetcore/0001-Run-GenerateFiles-during-source-build.patch
new file mode 100644
index 000000000000..e5d4b255191d
--- /dev/null
+++ b/src/SourceBuild/tarball/content/patches/aspnetcore/0001-Run-GenerateFiles-during-source-build.patch
@@ -0,0 +1,61 @@
+From db187e95f62d9bff268e68f39b441b6da8be9111 Mon Sep 17 00:00:00 2001
+From: Michael Simons <msimons@microsoft.com>
+Date: Mon, 2 Aug 2021 19:02:27 +0000
+Subject: [PATCH] Run GenerateFiles during source build
+
+GenerateFiles is not running in source build yet the outputs are required.
+These changes get GenerateFiles to run as part of source build.
+These changes also turn on the binaryLog option while building the RepoTasks during source build.
+---
+ eng/SourceBuild.props                        | 3 +--
+ eng/Tools.props                              | 2 +-
+ eng/tools/GenerateFiles/GenerateFiles.csproj | 1 +
+ 4 files changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/eng/SourceBuild.props b/eng/SourceBuild.props
+index 27cbe92036..3dbfe2ce7e 100644
+--- a/eng/SourceBuild.props
++++ b/eng/SourceBuild.props
+@@ -1,5 +1,4 @@
+ <Project>
+-
+   <PropertyGroup>
+     <GitHubRepositoryName>aspnetcore</GitHubRepositoryName>
+     <SourceBuildManagedOnly>true</SourceBuildManagedOnly>
+@@ -47,7 +46,7 @@
+           BeforeTargets="Execute">
+ 
+     <Exec
+-      Command="./eng/build.sh --only-build-repo-tasks"
++      Command="./eng/build.sh --only-build-repo-tasks -bl"
+       WorkingDirectory="$(InnerSourceBuildRepoRoot)"
+       EnvironmentVariables="@(InnerBuildEnv)" />
+   </Target>
+diff --git a/eng/Tools.props b/eng/Tools.props
+index a285c2406a..a38257f770 100644
+--- a/eng/Tools.props
++++ b/eng/Tools.props
+@@ -13,7 +13,7 @@
+   <!-- Update the generated files when we restore projects. Skip in desktop msbuild due to VS 16.8 requirements. -->
+   <Target Name="GenerateDirectoryBuildFiles"
+       AfterTargets="Restore"
+-      Condition=" '$(DotNetBuildFromSource)' != 'true' AND '$(MSBuildRuntimeType)' == 'core' ">
++      Condition=" '$(MSBuildRuntimeType)' == 'core' ">
+     <!-- Separate invocations and use different properties to ensure second can load the restored package info. -->
+     <MSBuild Projects="$(RepoRoot)eng\tools\GenerateFiles\GenerateFiles.csproj"
+         RemoveProperties="BaseIntermediateOutputPath"
+diff --git a/eng/tools/GenerateFiles/GenerateFiles.csproj b/eng/tools/GenerateFiles/GenerateFiles.csproj
+index 0ae5c9753e..dbf9965bf9 100644
+--- a/eng/tools/GenerateFiles/GenerateFiles.csproj
++++ b/eng/tools/GenerateFiles/GenerateFiles.csproj
+@@ -2,6 +2,7 @@
+   <PropertyGroup>
+     <!-- Use fixed version instead of $(DefaultNetCoreTargetFramework) to avoid needing workarounds set up here. -->
+     <TargetFramework>net5.0</TargetFramework>
++    <ExcludeFromSourceBuild>false</ExcludeFromSourceBuild>
+   </PropertyGroup>
+ 
+   <ItemGroup>
+-- 
+2.29.2
+
diff --git a/src/SourceBuild/tarball/content/patches/aspnetcore/0002-Use-Versions.props-MicrosoftExtensionsDependencyMode.patch b/src/SourceBuild/tarball/content/patches/aspnetcore/0002-Use-Versions.props-MicrosoftExtensionsDependencyMode.patch
new file mode 100644
index 000000000000..2a52ae6568a9
--- /dev/null
+++ b/src/SourceBuild/tarball/content/patches/aspnetcore/0002-Use-Versions.props-MicrosoftExtensionsDependencyMode.patch
@@ -0,0 +1,28 @@
+From 14992fbe4d8f433025cc45be81ef0035ed77221b Mon Sep 17 00:00:00 2001
+From: Michael Simons <msimons@microsoft.com>
+Date: Mon, 2 Aug 2021 13:40:03 +0000
+Subject: [PATCH] Use Versions.props MicrosoftExtensionsDependencyModelVersion
+ in RepoTasks
+
+Source build is loading a reference assembly which fails when the RepoTasks are invoked.
+This change gets source build to use the version which is source built.
+---
+ eng/tools/RepoTasks/RepoTasks.csproj | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/eng/tools/RepoTasks/RepoTasks.csproj b/eng/tools/RepoTasks/RepoTasks.csproj
+index e723beb353..67e01850f8 100644
+--- a/eng/tools/RepoTasks/RepoTasks.csproj
++++ b/eng/tools/RepoTasks/RepoTasks.csproj
+@@ -16,7 +16,7 @@
+ 
+   <ItemGroup>
+     <PackageReference Include="NuGet.Packaging" Version="$(NuGetPackagingVersion)" />
+-    <PackageReference Include="Microsoft.Extensions.DependencyModel" Version="2.1.0" />
++    <PackageReference Include="Microsoft.Extensions.DependencyModel" Version="$(MicrosoftExtensionsDependencyModelVersion)" />
+   </ItemGroup>
+ 
+   <ItemGroup Condition="'$(TargetFramework)' == '$(DefaultNetCoreTargetFramework)'">
+-- 
+2.29.2
+
diff --git a/src/SourceBuild/tarball/content/patches/aspnetcore/0003-Exclude-warnings-as-errors-from-source-build.patch b/src/SourceBuild/tarball/content/patches/aspnetcore/0003-Exclude-warnings-as-errors-from-source-build.patch
new file mode 100644
index 000000000000..cd82ffb9f02d
--- /dev/null
+++ b/src/SourceBuild/tarball/content/patches/aspnetcore/0003-Exclude-warnings-as-errors-from-source-build.patch
@@ -0,0 +1,34 @@
+From 6fce3b3afda68cd041cb3b38c8c21fa0513ab5e3 Mon Sep 17 00:00:00 2001
+From: Michael Simons <msimons@microsoft.com>
+Date: Mon, 2 Aug 2021 19:56:17 +0000
+Subject: [PATCH] Exclude warnings as errors from source build
+
+
+NU1604:  These hopefully go away once runtime-portable is added to the tarball.
+    Microsoft.AspNetCore.App.Runtime.csproj : error NU1604: Project dependency Microsoft.NETCore.App.Crossgen2.linux-x64 does not contain an inclusive lower bound. Include a lower bound in the dependency version to ensure consistent restore results.
+    Microsoft.AspNetCore.App.Runtime.csproj : error NU1604: Project dependency Microsoft.NETCore.App.Runtime.linux-x64 does not contain an inclusive lower bound. Include a lower bound in the dependency version to ensure consistent restore results.
+
+CS8601:
+   CascadingAuthenticationState.razor(4,108): error CS8601: Possible null reference assignment.
+---
+ Directory.Build.props | 4 ++++++++++++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/Directory.Build.props b/Directory.Build.props
+index ba1c1675a0..ce6bc50c66 100644
+--- a/Directory.Build.props
++++ b/Directory.Build.props
+@@ -225,6 +225,10 @@
+     <ArchiveExtension Condition="'$(TargetOsName)' == 'win'">.zip</ArchiveExtension>
+   </PropertyGroup>
+ 
++  <PropertyGroup>
++    <NoWarn>$(NoWarn);NU1604;CS8601</NoWarn>
++  </PropertyGroup>
++
+   <Import Project="eng\Workarounds.props" />
+   <Import Project="artifacts\bin\GenerateFiles\Directory.Build.props" Condition=" '$(MSBuildProjectName)' != 'GenerateFiles' " />
+   <Import Project="eng\Dependencies.props" />
+-- 
+2.29.2
+
diff --git a/src/SourceBuild/tarball/content/repos/Directory.Build.targets b/src/SourceBuild/tarball/content/repos/Directory.Build.targets
index 4e9c52ca9a9e..b78dfc8d7358 100644
--- a/src/SourceBuild/tarball/content/repos/Directory.Build.targets
+++ b/src/SourceBuild/tarball/content/repos/Directory.Build.targets
@@ -121,7 +121,7 @@
       <OldText><![CDATA[</Project>]]></OldText>
       <NewText>
         <![CDATA[  <PropertyGroup>
-    <NoWarn>$(NoWarn);NU5104</NoWarn>
+    <NoWarn>%24(NoWarn);NU5104</NoWarn>
   </PropertyGroup>
 </Project>]]>
       </NewText>
diff --git a/src/SourceBuild/tarball/content/repos/aspnetcore.proj b/src/SourceBuild/tarball/content/repos/aspnetcore.proj
index e8b821652d81..99ebb98bd2f1 100644
--- a/src/SourceBuild/tarball/content/repos/aspnetcore.proj
+++ b/src/SourceBuild/tarball/content/repos/aspnetcore.proj
@@ -1,66 +1,43 @@
 <Project>
-  <PropertyGroup>
-    <SourceDirectory>aspnetcore</SourceDirectory>
-  </PropertyGroup>
-
   <Import Project="Sdk.props" Sdk="Microsoft.NET.Sdk" />
 
   <PropertyGroup>
-    <OverrideTargetRid>$(TargetRid)</OverrideTargetRid>
-    <OverrideTargetRid Condition="'$(TargetOS)' == 'FreeBSD'">freebsd-x64</OverrideTargetRid>
-    <OverrideTargetRid Condition="'$(TargetOS)' == 'OSX'">osx-x64</OverrideTargetRid>
-
-    <BuildCommandArgs>$(BuildCommandArgs) --restore --build --pack</BuildCommandArgs>
-    <BuildCommandArgs>$(BuildCommandArgs) --configuration $(Configuration)</BuildCommandArgs>
-    <BuildCommandArgs>$(BuildCommandArgs) --ci</BuildCommandArgs>
-    <BuildCommandArgs>$(BuildCommandArgs) -bl</BuildCommandArgs>
-    <BuildCommandArgs>$(BuildCommandArgs) /v:$(LogVerbosity)</BuildCommandArgs>
+    <!-- StandardSourceBuildArgs include -publish which is not supported by the aspnetcore build script. -->
+    <BuildCommandArgs>$(StandardSourceBuildArgs.Replace('--publish', ''))</BuildCommandArgs>
     <!-- The arch flag (defaults to x64) overrides any value of TargetArchitecture that we might set -->
     <BuildCommandArgs>$(BuildCommandArgs) --arch $(Platform)</BuildCommandArgs>
+    <BuildCommandArgs>$(BuildCommandArgs) --no-build-repo-tasks</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) /p:BuildNodeJs=false</BuildCommandArgs>
-    <BuildCommandArgs>$(BuildCommandArgs) /p:SourceBuildRuntimeIdentifier=$(OverrideTargetRid)</BuildCommandArgs>
-    <BuildCommandArgs>$(BuildCommandArgs) /p:UseAppHost=false</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) /p:PublishCompressedFilesPathPrefix=$(SourceBuiltAspNetCoreRuntime)</BuildCommandArgs>
-
     <!-- Update to 1.0.0 version of reference assemblies which are built in SBRP instead of the preview.2 version
          included by Arcade -->
     <BuildCommandArgs>$(BuildCommandArgs) /p:MicrosoftNetFrameworkReferenceAssembliesVersion=1.0.0</BuildCommandArgs>
+    <BuildCommand>$(ProjectDirectory)\eng\build$(ShellExtension) $(BuildCommandArgs)</BuildCommand>
 
     <LogVerbosityOptOut>true</LogVerbosityOptOut>
 
-    <BuildCommand>$(ProjectDirectory)build$(ShellExtension) $(BuildCommandArgs)</BuildCommand>
-
-    <ShippingPackagesOutput>$(ProjectDirectory)artifacts/packages/$(Configuration)/Shipping/</ShippingPackagesOutput>
-    <NonShippingPackagesOutput>$(ProjectDirectory)artifacts/packages/$(Configuration)/NonShipping/</NonShippingPackagesOutput>
     <RepoApiImplemented>false</RepoApiImplemented>
     <DependencyVersionInputRepoApiImplemented>true</DependencyVersionInputRepoApiImplemented>
 
     <GlobalJsonFile>$(ProjectDirectory)global.json</GlobalJsonFile>
     <NuGetConfigFile>$(ProjectDirectory)NuGet.config</NuGetConfigFile>
-
-    <EnvironmentRestoreSources>$(SourceBuiltPackagesPath)</EnvironmentRestoreSources>
-    <EnvironmentRestoreSources>$(EnvironmentRestoreSources)%3B$(ReferencePackagesDir)%3B$(PrebuiltPackagesPath)</EnvironmentRestoreSources>
-    <EnvironmentRestoreSources Condition="'$(BuildWithOnlineSources)' == 'true'">$(EnvironmentRestoreSources)%3Bhttps://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public%40Local/nuget/v3/index.json</EnvironmentRestoreSources>
   </PropertyGroup>
 
   <ItemGroup>
     <RepositoryReference Include="arcade" />
-    <RepositoryReference Include="cssparser" />
-    <RepositoryReference Include="runtime" />
+    <RepositoryReference Include="source-build" />
+    <!-- TODO:  Enable with https://github.com/dotnet/source-build/issues/2274
+    <RepositoryReference Include="runtime" /> -->
     <RepositoryReference Include="msbuild" />
     <RepositoryReference Include="roslyn" />
-    <RepositoryReference Include="roslyn-analyzers" />
+    <!-- TODO:  https://github.com/dotnet/source-build/issues/2319
+    <RepositoryReference Include="roslyn-analyzers" /> -->
   </ItemGroup>
 
   <ItemGroup>
     <UseSourceBuiltSdkOverride Include="@(ArcadeSdkOverride)" />
   </ItemGroup>
 
-  <ItemGroup>
-    <EnvironmentVariables Include="RestoreSources=$(EnvironmentRestoreSources)" />
-    <EnvironmentVariables Include="DotNetPackageVersionPropsPath=$(PackageVersionPropsPath)" />
-  </ItemGroup>
-
   <UsingTask AssemblyFile="$(XPlatSourceBuildTasksAssembly)" TaskName="ReplaceRegexInFiles" />
 
   <Target Name="FixAspNetCoreVersion"
@@ -82,12 +59,5 @@
 
   </Target>
 
-  <Target Name="SetOutputList" AfterTargets="Package" BeforeTargets="GatherBuiltPackages">
-    <ItemGroup>
-      <PackagesOutputList Include="$(ShippingPackagesOutput)" />
-      <PackagesOutputList Include="$(NonShippingPackagesOutput)" />
-    </ItemGroup>
-  </Target>
-
   <Import Project="Sdk.targets" Sdk="Microsoft.NET.Sdk" />
 </Project>
diff --git a/src/SourceBuild/tarball/content/repos/known-good.proj b/src/SourceBuild/tarball/content/repos/known-good.proj
index 3e0144a0eb99..8b4d30c3b1ea 100644
--- a/src/SourceBuild/tarball/content/repos/known-good.proj
+++ b/src/SourceBuild/tarball/content/repos/known-good.proj
@@ -47,6 +47,9 @@
         <RepositoryReference Include="templating" />
 
         <!-- Tier 4 -->
+        <RepositoryReference Include="aspnetcore" />
+
+        <!-- Tier 5 -->
         <RepositoryReference Include="fsharp" />
         <RepositoryReference Include="vstest" />
 
diff --git a/src/SourceBuild/tarball/content/tools-local/tasks/Microsoft.DotNet.SourceBuild.Tasks.XPlat/FileUtilities.cs b/src/SourceBuild/tarball/content/tools-local/tasks/Microsoft.DotNet.SourceBuild.Tasks.XPlat/FileUtilities.cs
index 0365a7272d70..c249f5435f12 100644
--- a/src/SourceBuild/tarball/content/tools-local/tasks/Microsoft.DotNet.SourceBuild.Tasks.XPlat/FileUtilities.cs
+++ b/src/SourceBuild/tarball/content/tools-local/tasks/Microsoft.DotNet.SourceBuild.Tasks.XPlat/FileUtilities.cs
@@ -58,6 +58,12 @@ public static string NormalizeNewLineChars(string source, string newLineChars)
                 throw new ArgumentException("Unsupported new line characters", nameof(newLineChars));
             }
 
+            // Ensure trailing new line on linux.
+            if (newLineChars == LF && !source.EndsWith(newLineChars))
+            {
+                source += newLineChars;
+            }
+
             return source;
         }
     }