diff --git a/Directory.Build.props b/Directory.Build.props
index 9e8b408ef9af91..070c61866bedc4 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -130,7 +130,7 @@
     <MonoAOTCompilerTasksAssemblyPath>$([MSBuild]::NormalizePath('$(MonoAOTCompilerDir)', 'MonoAOTCompiler.dll'))</MonoAOTCompilerTasksAssemblyPath>
     <MonoTargetsTasksAssemblyPath>$([MSBuild]::NormalizePath('$(MonoTargetsTasksDir)', 'MonoTargetsTasks.dll'))</MonoTargetsTasksAssemblyPath>
     <TestExclusionListTasksAssemblyPath>$([MSBuild]::NormalizePath('$(TestExclusionListTasksDir)', 'TestExclusionListTasks.dll'))</TestExclusionListTasksAssemblyPath>
-    <CoreCLRToolPath>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'coreclr', '$(TargetOS).$(TargetArchitecture).$(Configuration)'))</CoreCLRToolPath>
+    <CoreCLRToolPath>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'coreclr', '$(TargetOS).$(TargetArchitecture).$(RuntimeConfiguration)'))</CoreCLRToolPath>
     <ILAsmToolPath Condition="'$(DotNetBuildFromSource)' == 'true' or '$(BuildArchitecture)' == 's390x' or '$(BuildArchitecture)' == 'ppc64le'">$(CoreCLRToolPath)</ILAsmToolPath>
 
     <WasmtimeDir>$([MSBuild]::NormalizeDirectory($(ArtifactsObjDir), 'wasmtime'))</WasmtimeDir>
@@ -151,11 +151,14 @@
 
   <PropertyGroup Label="CalculateOS">
     <!-- Default to portable build if not explicitly set -->
+    <PortableBuild Condition="'$(PortableBuild)' == '' and '$(DotNetBuildFromSource)' == 'true'">false</PortableBuild>
     <PortableBuild Condition="'$(PortableBuild)' == ''">true</PortableBuild>
 
+    <_hostRid Condition="'$(MSBuildRuntimeType)' == 'core'">$([System.Runtime.InteropServices.RuntimeInformation]::RuntimeIdentifier)</_hostRid>
+    <_hostRid Condition="'$(MSBuildRuntimeType)' != 'core'">win-$([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture.ToString().ToLowerInvariant)</_hostRid>
+
     <_parseDistroRid>$(__DistroRid)</_parseDistroRid>
-    <_parseDistroRid Condition="'$(_parseDistroRid)' == '' and '$(MSBuildRuntimeType)' == 'core'">$([System.Runtime.InteropServices.RuntimeInformation]::RuntimeIdentifier)</_parseDistroRid>
-    <_parseDistroRid Condition="'$(_parseDistroRid)' == '' and '$(MSBuildRuntimeType)' != 'core'">win-$([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture.ToString().ToLowerInvariant)</_parseDistroRid>
+    <_parseDistroRid Condition="'$(_parseDistroRid)' == ''">$(_hostRid)</_parseDistroRid>
     <_distroRidIndex>$(_parseDistroRid.LastIndexOf('-'))</_distroRidIndex>
 
     <_runtimeOS>$(RuntimeOS)</_runtimeOS>
@@ -184,6 +187,7 @@
 
     <_runtimeOS Condition="$(_runtimeOS.StartsWith('tizen'))">linux</_runtimeOS>
     <_runtimeOS Condition="'$(PortableBuild)' == 'true'">$(_portableOS)</_runtimeOS>
+    <_runtimeOS Condition="'$(RuntimeOS)' == '' and '$(DotNetBuildFromSource)' == 'true'">$(_portableOS)</_runtimeOS>
 
     <_packageLibc Condition="$(_runtimeOS.Contains('musl'))">-musl</_packageLibc>
     <_packageOS Condition="'$(CrossBuild)' == 'true'">$(_hostOS)$(_packageLibc)</_packageOS>
@@ -216,6 +220,7 @@
 
     <PackageRID>$(_packageOS)-$(TargetArchitecture)</PackageRID>
 
+    <OutputRid Condition="'$(OutputRid)' == '' and '$(DotNetBuildFromSource)' == 'true'">$(_hostRid)</OutputRid>
     <OutputRid Condition="'$(OutputRid)' == ''">$(PackageRID)</OutputRid>
     <OutputRid Condition="'$(PortableBuild)' == 'true'">$(_portableOS)-$(TargetArchitecture)</OutputRid>
     <TargetsLinuxBionic Condition="$(OutputRid.StartsWith('linux-bionic'))">true</TargetsLinuxBionic>
@@ -258,6 +263,8 @@
 
   <!--Feature switches -->
   <PropertyGroup>
+    <NoPgoOptimize Condition="'$(NoPgoOptimize)' == '' and '$(DotNetBuildFromSource)' == 'true'">true</NoPgoOptimize>
+    <EnableNgenOptimization Condition="'$(EnableNgenOptimization)' == '' and '$(DotNetBuildFromSource)' == 'true'">false</EnableNgenOptimization>
     <EnableNgenOptimization Condition="'$(EnableNgenOptimization)' == '' and ('$(Configuration)' == 'Release' or '$(Configuration)' == 'Checked')">true</EnableNgenOptimization>
     <!-- Enable NuGet static graph evaluation to optimize incremental restore -->
     <RestoreUseStaticGraphEvaluation>true</RestoreUseStaticGraphEvaluation>
@@ -324,7 +331,7 @@
     <!-- Always pass portable to override arcade sdk which uses embedded for local builds -->
     <DebugType>portable</DebugType>
     <DebugSymbols>true</DebugSymbols>
-    <!-- Default to discarding symbols if not explicitly set -->
+    <KeepNativeSymbols Condition="'$(KeepNativeSymbols)' == '' and '$(DotNetBuildFromSource)' == 'true'">true</KeepNativeSymbols>
     <KeepNativeSymbols Condition="'$(KeepNativeSymbols)' == ''">false</KeepNativeSymbols>
     <!-- Used for launchSettings.json and runtime config files. -->
     <AppDesignerFolder>Properties</AppDesignerFolder>
diff --git a/eng/SourceBuild.props b/eng/SourceBuild.props
index 4b4ba966025676..4f907f62538fd5 100644
--- a/eng/SourceBuild.props
+++ b/eng/SourceBuild.props
@@ -8,9 +8,6 @@
   <PropertyGroup>
     <BaseInnerSourceBuildCommand>./build.sh</BaseInnerSourceBuildCommand>
 
-    <SourceBuildPortable>true</SourceBuildPortable>
-    <SourceBuildPortable Condition="'$(SourceBuildNonPortable)' == 'true'">false</SourceBuildPortable>
-
     <!-- TargetRid names what gets built. -->
     <TargetRid Condition="'$(TargetRid)' == '' and '$(SourceBuildNonPortable)' == 'true'">$([System.Runtime.InteropServices.RuntimeInformation]::RuntimeIdentifier)</TargetRid>
     <TargetRid Condition="'$(TargetRid)' == ''">$(__DistroRid)</TargetRid>
@@ -32,6 +29,9 @@
   <Target Name="GetRuntimeSourceBuildCommandConfiguration"
           BeforeTargets="GetSourceBuildCommandConfiguration">
     <PropertyGroup>
+      <!-- Properties that control the source-build configuration should be added to the repository and guarded with the DotNetBuildFromSource Condition.
+           This allows to build the repository using './build.sh <args> /p:DotNetBuildFromSource=true'.
+           Properties that control flags from source-build, and the expected output for source-build should be added to this file. -->
       <InnerBuildArgs>$(InnerBuildArgs) --arch $(TargetArch)</InnerBuildArgs>
       <InnerBuildArgs>$(InnerBuildArgs) --configuration $(Configuration)</InnerBuildArgs>
       <InnerBuildArgs>$(InnerBuildArgs) --allconfigurations</InnerBuildArgs>
@@ -39,18 +39,10 @@
       <InnerBuildArgs>$(InnerBuildArgs) --nodereuse false</InnerBuildArgs>
       <InnerBuildArgs>$(InnerBuildArgs) --warnAsError false</InnerBuildArgs>
       <InnerBuildArgs>$(InnerBuildArgs) --outputrid $(TargetRid)</InnerBuildArgs>
-      <InnerBuildArgs>$(InnerBuildArgs) --portablebuild $(SourceBuildPortable)</InnerBuildArgs>
-      <InnerBuildArgs>$(InnerBuildArgs) /p:NoPgoOptimize=true</InnerBuildArgs>
-      <InnerBuildArgs>$(InnerBuildArgs) /p:KeepNativeSymbols=true</InnerBuildArgs>
       <InnerBuildArgs>$(InnerBuildArgs) /p:RuntimeOS=$(RuntimeOS)</InnerBuildArgs>
       <InnerBuildArgs Condition="'$(OfficialBuildId)' != ''">$(InnerBuildArgs) /p:OfficialBuildId=$(OfficialBuildId)</InnerBuildArgs>
       <InnerBuildArgs Condition="'$(ContinuousIntegrationBuild)' != ''">$(InnerBuildArgs) /p:ContinuousIntegrationBuild=$(ContinuousIntegrationBuild)</InnerBuildArgs>
-      <InnerBuildArgs>$(InnerBuildArgs) /p:BuildDebPackage=false</InnerBuildArgs>
-      <InnerBuildArgs>$(InnerBuildArgs) /p:EnableNgenOptimization=false</InnerBuildArgs>
       <InnerBuildArgs>$(InnerBuildArgs) /p:AdditionalRuntimeIdentifierParent=$(BaseOS)</InnerBuildArgs>
-      <InnerBuildArgs>$(InnerBuildArgs) /p:EnablePackageValidation=false</InnerBuildArgs>
-      <!-- Re-enable for source-build when 8.0 Preview 1 shipped. See https://github.com/dotnet/installer/pull/14991 for more information. -->
-      <InnerBuildArgs>$(InnerBuildArgs) /p:ApiCompatValidateAssemblies=false</InnerBuildArgs>
       <InnerBuildArgs Condition="'$(SourceBuildUseMonoRuntime)' == 'true'">$(InnerBuildArgs) /p:PrimaryRuntimeFlavor=Mono /p:RuntimeFlavor=Mono</InnerBuildArgs>
     </PropertyGroup>
   </Target>
diff --git a/eng/packaging.targets b/eng/packaging.targets
index e5cfa659cfaf97..d1fb653c6f928a 100644
--- a/eng/packaging.targets
+++ b/eng/packaging.targets
@@ -2,7 +2,9 @@
 
   <PropertyGroup>
     <!-- Package Validation isn't helpful when authoring shared framework packages. -->
-    <EnablePackageValidation Condition="'$(EnablePackageValidation)' == '' and '$(UsingMicrosoftDotNetSharedFrameworkSdk)' != 'true'">true</EnablePackageValidation>
+    <EnablePackageValidation Condition="'$(EnablePackageValidation)' == '' and
+                                        '$(UsingMicrosoftDotNetSharedFrameworkSdk)' != 'true' and
+                                        '$(DotNetBuildFromSource)' != 'true'">true</EnablePackageValidation>
     <!-- Don't perform baseline validation if we don't have a stable prebuilt version.
          Don't attempt to restore prebuilts during source-build. -->
     <DisablePackageBaselineValidation Condition="'$(IsShipping)' == 'false' or
diff --git a/src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs b/src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs
index 9d81146e977cbe..3148422ee78869 100644
--- a/src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs
+++ b/src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs
@@ -420,8 +420,10 @@ private static bool GetProtocolSupportFromWindowsRegistry(SslProtocols protocol,
 #pragma warning disable CS0618 // Ssl2 and Ssl3 are obsolete
                 SslProtocols.Ssl3 => "SSL 3.0",
 #pragma warning restore CS0618
+#pragma warning disable SYSLIB0039 // TLS versions 1.0 and 1.1 have known vulnerabilities
                 SslProtocols.Tls => "TLS 1.0",
                 SslProtocols.Tls11 => "TLS 1.1",
+#pragma warning restore SYSLIB0039
                 SslProtocols.Tls12 => "TLS 1.2",
 #if !NETFRAMEWORK
                 SslProtocols.Tls13 => "TLS 1.3",
@@ -491,6 +493,7 @@ private static bool AndroidGetSslProtocolSupport(SslProtocols protocol)
             return (protocol & s_androidSupportedSslProtocols.Value) == protocol;
         }
 
+#pragma warning disable SYSLIB0039 // TLS versions 1.0 and 1.1 have known vulnerabilities
         private static bool GetTls10Support()
         {
             // on macOS and Android TLS 1.0 is supported.
@@ -529,6 +532,7 @@ private static bool GetTls11Support()
 
             return OpenSslGetTlsSupport(SslProtocols.Tls11);
         }
+#pragma warning restore SYSLIB0039
 
         private static bool GetTls12Support()
         {
diff --git a/src/libraries/Common/tests/TestUtilities/System/WindowsIdentityFixture.cs b/src/libraries/Common/tests/TestUtilities/System/WindowsIdentityFixture.cs
index ae5a86b1e74203..0f0ff0c2cce1e2 100644
--- a/src/libraries/Common/tests/TestUtilities/System/WindowsIdentityFixture.cs
+++ b/src/libraries/Common/tests/TestUtilities/System/WindowsIdentityFixture.cs
@@ -118,8 +118,8 @@ private void CreateUser()
         [return: MarshalAs(UnmanagedType.Bool)]
         private static partial bool LogonUser(string userName, string domain, string password, int logonType, int logonProvider, out SafeAccessTokenHandle safeAccessTokenHandle);
 
-        [LibraryImport("netapi32.dll", SetLastError = true)]
-        internal static partial uint NetUserAdd([MarshalAs(UnmanagedType.LPWStr)] string servername, uint level, ref USER_INFO_1 buf, out uint parm_err);
+        [DllImport("netapi32.dll", SetLastError = true)]
+        internal static extern uint NetUserAdd([MarshalAs(UnmanagedType.LPWStr)] string servername, uint level, ref USER_INFO_1 buf, out uint parm_err);
 
         [LibraryImport("netapi32.dll")]
         internal static partial uint NetUserDel([MarshalAs(UnmanagedType.LPWStr)] string servername, [MarshalAs(UnmanagedType.LPWStr)] string username);
diff --git a/src/libraries/Microsoft.NETCore.Platforms/tests/Microsoft.NETCore.Platforms.Tests.csproj b/src/libraries/Microsoft.NETCore.Platforms/tests/Microsoft.NETCore.Platforms.Tests.csproj
index 2622635380116f..d4b11af0a96d6a 100644
--- a/src/libraries/Microsoft.NETCore.Platforms/tests/Microsoft.NETCore.Platforms.Tests.csproj
+++ b/src/libraries/Microsoft.NETCore.Platforms/tests/Microsoft.NETCore.Platforms.Tests.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>$(NetCoreAppCurrent);net472</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent);$(NetFrameworkToolCurrent)</TargetFrameworks>
     <IgnoreForCI Condition="'$(TargetOS)' == 'browser'">true</IgnoreForCI>
   </PropertyGroup>
 
diff --git a/src/tests/Directory.Build.props b/src/tests/Directory.Build.props
index d09ffadace18e9..437d976fa78b37 100644
--- a/src/tests/Directory.Build.props
+++ b/src/tests/Directory.Build.props
@@ -74,7 +74,6 @@
     <RuntimeFlavor Condition="'$(RuntimeFlavor)' == ''">coreclr</RuntimeFlavor>
 
     <RestoreDefaultOptimizationDataPackage Condition="'$(RestoreDefaultOptimizationDataPackage)' == ''">false</RestoreDefaultOptimizationDataPackage>
-    <PortableBuild Condition="'$(PortableBuild)' == ''">true</PortableBuild>
 
     <UsePartialNGENOptimization Condition="'$(UsePartialNGENOptimization)' == ''">false</UsePartialNGENOptimization>