diff --git a/eng/Configurations.props b/eng/Configurations.props
index 764887c3ae5a6f..94646e7991b87c 100644
--- a/eng/Configurations.props
+++ b/eng/Configurations.props
@@ -43,6 +43,7 @@
     <TargetOS Condition="'$(TargetOS)' == '' and $([MSBuild]::IsOSPlatform('OSX'))">OSX</TargetOS>
     <TargetOS Condition="'$(TargetOS)' == '' and $([MSBuild]::IsOSPlatform('FREEBSD'))">FreeBSD</TargetOS>
     <TargetOS Condition="'$(TargetOS)' == '' and $([MSBuild]::IsOSPlatform('NETBSD'))">NetBSD</TargetOS>
+    <TargetOS Condition="'$(TargetOS)' == '' and $([MSBuild]::IsOSPlatform('SUNOS'))">SunOS</TargetOS>
     <TargetOS Condition="'$(TargetOS)' == '' and $([MSBuild]::IsOSUnixLike())">Linux</TargetOS>
     <TargetOS Condition="'$(TargetOS)' == '' and $([MSBuild]::IsOSPlatform('WINDOWS'))">Windows_NT</TargetOS>
     <CoreCLRTargetOS Condition="'$(CoreCLRTargetOS)' == ''">$(TargetOS)</CoreCLRTargetOS>
diff --git a/eng/build.sh b/eng/build.sh
index 64496fd1080506..36e68ef1c1dc42 100755
--- a/eng/build.sh
+++ b/eng/build.sh
@@ -18,7 +18,7 @@ usage()
 {
   echo "Common settings:"
   echo "  --subset                   Build a subset, print available subsets with -subset help (short: -s)"
-  echo "  --os                       Build operating system: Windows_NT, Linux, FreeBSD, OSX, tvOS, iOS, Android or Browser"
+  echo "  --os                       Build operating system: Windows_NT, Linux, FreeBSD, OSX, tvOS, iOS, Android, Browser, NetBSD or SunOS"
   echo "  --arch                     Build platform: x86, x64, arm, armel, arm64 or wasm"
   echo "  --configuration            Build configuration: Debug, Release or [CoreCLR]Checked (short: -c)"
   echo "  --runtimeConfiguration     Runtime build configuration: Debug, Release or [CoreCLR]Checked (short: -rc)"
@@ -108,16 +108,16 @@ while [[ $# > 0 ]]; do
       exit 0
       ;;
      -subset|-s)
-      if [ -z ${2+x} ]; then 
+      if [ -z ${2+x} ]; then
         arguments="$arguments /p:Subset=help"
         shift 1
-      else 
+      else
         arguments="$arguments /p:Subset=$2"
         shift 2
       fi
       ;;
      -arch)
-      if [ -z ${2+x} ]; then 
+      if [ -z ${2+x} ]; then
         echo "No architecture supplied. See help (--help) for supported architectures." 1>&2
         exit 1
       fi
@@ -125,7 +125,7 @@ while [[ $# > 0 ]]; do
       shift 2
       ;;
      -configuration|-c)
-     if [ -z ${2+x} ]; then 
+     if [ -z ${2+x} ]; then
         echo "No configuration supplied. See help (--help) for supported configurations." 1>&2
         exit 1
       fi
@@ -134,7 +134,7 @@ while [[ $# > 0 ]]; do
       shift 2
       ;;
      -framework|-f)
-      if [ -z ${2+x} ]; then 
+      if [ -z ${2+x} ]; then
         echo "No framework supplied. See help (--help) for supported frameworks." 1>&2
         exit 1
       fi
@@ -143,7 +143,7 @@ while [[ $# > 0 ]]; do
       shift 2
       ;;
      -os)
-      if [ -z ${2+x} ]; then 
+      if [ -z ${2+x} ]; then
         echo "No target operating system supplied. See help (--help) for supported target operating systems." 1>&2
         exit 1
       fi
@@ -156,7 +156,7 @@ while [[ $# > 0 ]]; do
       shift 1
       ;;
      -testscope)
-      if [ -z ${2+x} ]; then 
+      if [ -z ${2+x} ]; then
         echo "No test scope supplied. See help (--help) for supported test scope values." 1>&2
         exit 1
       fi
@@ -172,7 +172,7 @@ while [[ $# > 0 ]]; do
       shift 1
       ;;
      -runtimeconfiguration|-rc)
-      if [ -z ${2+x} ]; then 
+      if [ -z ${2+x} ]; then
         echo "No runtime configuration supplied. See help (--help) for supported runtime configurations." 1>&2
         exit 1
       fi
@@ -181,7 +181,7 @@ while [[ $# > 0 ]]; do
       shift 2
       ;;
      -librariesconfiguration|-lc)
-      if [ -z ${2+x} ]; then 
+      if [ -z ${2+x} ]; then
         echo "No libraries configuration supplied. See help (--help) for supported libraries configurations." 1>&2
         exit 1
       fi
@@ -198,7 +198,7 @@ while [[ $# > 0 ]]; do
       shift 1
       ;;
      -cmakeargs)
-      if [ -z ${2+x} ]; then 
+      if [ -z ${2+x} ]; then
         echo "No cmake args supplied." 1>&2
         exit 1
       fi
diff --git a/eng/native/build-commons.sh b/eng/native/build-commons.sh
index 27381c68d0e35b..309244b9671cc3 100755
--- a/eng/native/build-commons.sh
+++ b/eng/native/build-commons.sh
@@ -409,7 +409,7 @@ done
 # Get the number of processors available to the scheduler
 # Other techniques such as `nproc` only get the number of
 # processors available to a single process.
-platform=$(uname)
+platform="$(uname)"
 if [[ "$platform" == "FreeBSD" ]]; then
   __NumProc=$(sysctl hw.ncpu | awk '{ print $2+1 }')
 elif [[ "$platform" == "NetBSD" || "$platform" == "SunOS" ]]; then
diff --git a/eng/native/configurecompiler.cmake b/eng/native/configurecompiler.cmake
index 735f77b0282178..e0301cb6b3fc13 100644
--- a/eng/native/configurecompiler.cmake
+++ b/eng/native/configurecompiler.cmake
@@ -227,15 +227,13 @@ if (CLR_CMAKE_HOST_UNIX)
 
   if(CLR_CMAKE_HOST_OSX)
     message("Detected OSX x86_64")
-  endif(CLR_CMAKE_HOST_OSX)
-
-  if(CLR_CMAKE_HOST_FREEBSD)
+  elseif(CLR_CMAKE_HOST_FREEBSD)
     message("Detected FreeBSD amd64")
-  endif(CLR_CMAKE_HOST_FREEBSD)
-
-  if(CLR_CMAKE_HOST_NETBSD)
+  elseif(CLR_CMAKE_HOST_NETBSD)
     message("Detected NetBSD amd64")
-  endif(CLR_CMAKE_HOST_NETBSD)
+  elseif(CLR_CMAKE_HOST_SUNOS)
+    message("Detected SunOS amd64")
+  endif(CLR_CMAKE_HOST_SUNOS)
 endif(CLR_CMAKE_HOST_UNIX)
 
 if (CLR_CMAKE_HOST_WIN32)
@@ -373,6 +371,8 @@ if(CLR_CMAKE_TARGET_UNIX)
     add_definitions(-DTARGET_LINUX)
   elseif(CLR_CMAKE_TARGET_NETBSD)
     add_definitions(-DTARGET_NETBSD)
+  elseif(CLR_CMAKE_TARGET_SUNOS)
+    add_definitions(-DTARGET_SUNOS)
   elseif(CLR_CMAKE_TARGET_ANDROID)
     add_definitions(-DTARGET_ANDROID)
   endif()
diff --git a/eng/run-test.sh b/eng/run-test.sh
index abd1d920b1615a..5f14e6f6121bec 100644
--- a/eng/run-test.sh
+++ b/eng/run-test.sh
@@ -15,12 +15,12 @@ wait_on_pids()
 
 usage()
 {
-    echo "Runs .NET CoreFX tests on FreeBSD, NetBSD or Linux"
+    echo "Runs .NET CoreFX tests on FreeBSD, Linux, NetBSD or SunOS"
     echo "usage: run-test [options]"
     echo
     echo "Input sources:"
     echo "    --runtime <location>              Location of root of the binaries directory"
-    echo "                                      containing the FreeBSD, NetBSD or Linux runtime"
+    echo "                                      containing the FreeBSD, Linux, NetBSD or SunOS runtime"
     echo "                                      default: <repo_root>/bin/testhost/netcoreapp-<OS>-<Configuration>-<Arch>"
     echo "    --corefx-tests <location>         Location of the root binaries location containing"
     echo "                                      the tests to run"
@@ -29,7 +29,7 @@ usage()
     echo "Flavor/OS/Architecture options:"
     echo "    --configuration <config>     Configuration to run (Debug/Release)"
     echo "                                      default: Debug"
-    echo "    --os <os>                         OS to run (FreeBSD, NetBSD or Linux)"
+    echo "    --os <os>                         OS to run (FreeBSD, Linux, NetBSD or SunOS)"
     echo "                                      default: detect current OS"
     echo "    --arch <Architecture>             Architecture to run (x64, arm, armel, x86, arm64)"
     echo "                                      default: detect current architecture"
@@ -236,34 +236,34 @@ done
 
 # Compute paths to the binaries if they haven't already been computed
 
-if [ "$Runtime" == "" ]
+if [ -z "$Runtime" ]
 then
     Runtime="$ProjectRoot/artifacts/bin/testhost/netcoreapp-$OS-$Configuration-$__Arch"
 fi
 
-if [ "$CoreFxTests" == "" ]
+if [ -z "$CoreFxTests" ]
 then
     CoreFxTests="$ProjectRoot/artifacts/bin"
 fi
 
 # Check parameters up front for valid values:
 
-if [ ! "$Configuration" == "Debug" ] && [ ! "$Configuration" == "Release" ]
+if [ "$Configuration" != "Debug" ] && [ "$Configuration" != "Release" ]
 then
     echo "error: Configuration should be Debug or Release"
     exit 1
 fi
 
-if [ ! "$OS" == "FreeBSD" ] && [ ! "$OS" == "NetBSD" ] && [ ! "$OS" == "Linux" ]
+if [ "$OS" != "FreeBSD" ] && [ "$OS" != "Linux" ] && [ "$OS" != "NetBSD" ] && [ "$OS" != "SunOS" ]
 then
-    echo "error: OS should be FreeBSD, NetBSD or Linux"
+    echo "error: OS should be FreeBSD, Linux, NetBSD or Linux"
     exit 1
 fi
 
 export CORECLR_SERVER_GC="$serverGC"
 export PAL_OUTPUTDEBUGSTRING="1"
 
-if [ "$LANG" == "" ]
+if [ -z "$LANG" ]
 then
     export LANG="en_US.UTF-8"
 fi
@@ -285,7 +285,10 @@ if [ $RunTestSequential -eq 1 ]
 then
     maxProcesses=1;
 else
-    if [ `uname` = "NetBSD" ] || [ `uname` = "FreeBSD" ]; then
+    platform="$(uname)"
+    if [ "$platform" = "FreeBSD" ]; then
+      maxProcesses=$(sysctl hw.ncpu | awk '{ print $2+1 }')
+    if [ "$platform" = "NetBSD" ] || [ "$platform" = "SunOS" ] ; then
       maxProcesses=$(($(getconf NPROCESSORS_ONLN)+1))
     else
       maxProcesses=$(($(getconf _NPROCESSORS_ONLN)+1))
diff --git a/eng/targetframeworksuffix.props b/eng/targetframeworksuffix.props
index 2f427328fd5fd6..f89923d3ab86ce 100644
--- a/eng/targetframeworksuffix.props
+++ b/eng/targetframeworksuffix.props
@@ -62,6 +62,13 @@
         <PackageTargetRuntime>netbsd</PackageTargetRuntime>
       </PropertyGroup>
     </When>
+    <When Condition="'$(TargetFrameworkSuffix)' == 'SunOS'">
+      <PropertyGroup>
+        <TargetsUnix>true</TargetsUnix>
+        <TargetsSunOS>true</TargetsSunOS>
+        <PackageTargetRuntime>sunos</PackageTargetRuntime>
+      </PropertyGroup>
+    </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Browser'">
       <PropertyGroup>
         <TargetsLinux>true</TargetsLinux>
diff --git a/src/coreclr/dir.common.props b/src/coreclr/dir.common.props
index e4d212b2aee164..2ff54f14de24a2 100644
--- a/src/coreclr/dir.common.props
+++ b/src/coreclr/dir.common.props
@@ -55,10 +55,11 @@
     <TargetsFreeBSD Condition="'$(TargetOS)' == 'FreeBSD'">true</TargetsFreeBSD>
     <TargetsLinux Condition="'$(TargetOS)' == 'Linux'">true</TargetsLinux>
     <TargetsNetBSD Condition="'$(TargetOS)' == 'NetBSD'">true</TargetsNetBSD>
+    <TargetsSunOS Condition="'$(TargetOS)' == 'SunOS'">true</TargetsSunOS>
     <TargetsOSX Condition="'$(TargetOS)' == 'OSX'">true</TargetsOSX>
     <TargetsWindows Condition="'$(TargetOS)' == 'Windows_NT'">true</TargetsWindows>
 
-    <TargetsUnix Condition="'$(TargetsFreeBSD)' == 'true' or '$(TargetsLinux)' == 'true' or '$(TargetsNetBSD)' == 'true' or '$(TargetsOSX)' == 'true'">true</TargetsUnix>
+    <TargetsUnix Condition="'$(TargetsFreeBSD)' == 'true' or '$(TargetsLinux)' == 'true' or '$(TargetsNetBSD)' == 'true' or '$(TargetsOSX)' == 'true' or '$(TargetsSunOS)' == 'true'">true</TargetsUnix>
 
     <!-- We are only tracking Linux Distributions for Nuget RID mapping -->
     <DistroRid Condition="'$(TargetsLinux)' == 'true'">$(__DistroRid)</DistroRid>
diff --git a/src/coreclr/run-cppcheck.sh b/src/coreclr/run-cppcheck.sh
index c505fd184dedc3..46e51e1e7471fc 100755
--- a/src/coreclr/run-cppcheck.sh
+++ b/src/coreclr/run-cppcheck.sh
@@ -17,13 +17,13 @@ usage()
 check_dependencies()
 {
     # Check presence of cppcheck on the path
-    if [ "$RunCppCheck" == true ]
+    if [ "$RunCppCheck" = "true" ]
     then
         hash cppcheck 2>/dev/null || { echo >&2 "Please install cppcheck before running this script"; exit 1; }
     fi
-    
+
     # Check presence of sloccount on the path
-    if [ "$RunSlocCount" == true ]
+    if [ "$RunSlocCount" = "true" ]
     then
         hash sloccount 2>/dev/null || { echo >&2 "Please install sloccount before running this script"; exit 1; }
     fi
@@ -39,9 +39,10 @@ SloccountOutput="sloccount.sc"
 # Get the number of processors available to the scheduler
 # Other techniques such as `nproc` only get the number of
 # processors available to a single process.
-if [ `uname` = "FreeBSD" ]; then
-NumProc=`sysctl hw.ncpu | awk '{ print $2+1 }'`
-elif [ `uname` = "NetBSD" ]; then
+platform="$(uname)"
+if [ "$platform" = "FreeBSD" ]; then
+NumProc=$(sysctl hw.ncpu | awk '{ print $2+1 }')
+elif [ "$platform" = "NetBSD" || "$platform" = "SunOS" ]; then
 NumProc=$(($(getconf NPROCESSORS_ONLN)+1))
 else
 NumProc=$(($(getconf _NPROCESSORS_ONLN)+1))
@@ -80,19 +81,19 @@ do
     esac
 done
 
-if [ "$FilesFromArgs" != "" ];
+if [ -n "$FilesFromArgs" ];
 then
     Files=$FilesFromArgs
 fi
 
-if [ "$CppCheckOutput" == "" ];
+if [ -z "$CppCheckOutput" ];
 then
     echo "Expected: file for cppcheck output"
     usage
     exit 1
 fi
 
-if [ "$SloccountOutput" == "" ];
+if [ -z "$SloccountOutput" ];
 then
     echo "Expected: file for sloccount output"
     usage
@@ -101,14 +102,14 @@ fi
 
 check_dependencies
 
-if [ "$RunCppCheck" == true ]
+if [ "$RunCppCheck" = "true" ]
 then
     echo "Running cppcheck for files: $Files"
     cppcheck --enable=all -j $NumProc --xml --xml-version=2 --force $Files 2> $CppCheckOutput
     CppCheckOutputs="$CppCheckOutput (cppcheck)"
 fi
 
-if [ "$RunSlocCount" == true ]
+if [ "$RunSlocCount" = "true" ]
 then
     echo "Running sloccount for files: $Files"
     sloccount --wide --details $Files > $SloccountOutput
diff --git a/src/coreclr/src/.nuget/Directory.Build.props b/src/coreclr/src/.nuget/Directory.Build.props
index e321b384626e0e..2fd932c03b84ee 100644
--- a/src/coreclr/src/.nuget/Directory.Build.props
+++ b/src/coreclr/src/.nuget/Directory.Build.props
@@ -28,7 +28,7 @@
 
     <RuntimeOS Condition="'$(RuntimeOS)' == ''">$(OSRid)</RuntimeOS>
 
-    <SupportedPackageOSGroups Condition="'$(SupportedPackageOSGroups)' == ''">Windows_NT;OSX;Android;Linux;FreeBSD</SupportedPackageOSGroups>
+    <SupportedPackageOSGroups Condition="'$(SupportedPackageOSGroups)' == ''">Windows_NT;OSX;Android;Linux;FreeBSD;NetBSD;SunOS</SupportedPackageOSGroups>
     <SupportedPackageOSGroups>;$(SupportedPackageOSGroups);</SupportedPackageOSGroups>
 
     <!-- Identify OS family based upon the RuntimeOS, which could be distro specific (e.g. osx.10.12) or
@@ -96,6 +96,20 @@
         <PackageRID Condition="'$(PortableBuild)' == 'true'">freebsd-$(TargetArchitecture)</PackageRID>
       </PropertyGroup>
     </When>
+    <When Condition="'$(_runtimeOSFamily)' == 'netbsd'">
+      <PropertyGroup>
+        <PackageRID>netbsd-$(TargetArchitecture)</PackageRID>
+        <!-- Set the platform part of the RID if we are doing a portable build -->
+        <PackageRID Condition="'$(PortableBuild)' == 'true'">netbsd-$(TargetArchitecture)</PackageRID>
+      </PropertyGroup>
+    </When>
+    <When Condition="'$(_runtimeOSFamily)' == 'sunos'">
+      <PropertyGroup>
+        <PackageRID>sunos-$(TargetArchitecture)</PackageRID>
+        <!-- Set the platform part of the RID if we are doing a portable build -->
+        <PackageRID Condition="'$(PortableBuild)' == 'true'">sunos-$(TargetArchitecture)</PackageRID>
+      </PropertyGroup>
+    </When>
     <When Condition="'$(_runtimeOSFamily)' == 'android'">
       <PropertyGroup>
         <PackageRID>android.21-$(TargetArchitecture)</PackageRID>
@@ -159,6 +173,12 @@
   <ItemGroup Condition="$(SupportedPackageOSGroups.Contains(';FreeBSD;'))">
     <OfficialBuildRID Include="freebsd-x64" />
   </ItemGroup>
+  <ItemGroup Condition="$(SupportedPackageOSGroups.Contains(';NetBSD;'))">
+    <OfficialBuildRID Include="netbsd-x64" />
+  </ItemGroup>
+  <ItemGroup Condition="$(SupportedPackageOSGroups.Contains(';SunOS;'))">
+    <OfficialBuildRID Include="sunos-x64" />
+  </ItemGroup>
   <ItemGroup Condition="$(SupportedPackageOSGroups.Contains(';Windows_NT;'))">
     <OfficialBuildRID Include="win-x86">
       <Platform>x86</Platform>
diff --git a/src/coreclr/src/.nuget/Microsoft.NET.Sdk.IL/targets/Microsoft.NET.Sdk.IL.targets b/src/coreclr/src/.nuget/Microsoft.NET.Sdk.IL/targets/Microsoft.NET.Sdk.IL.targets
index 299511fa2a8be4..f2c0a3fb649733 100644
--- a/src/coreclr/src/.nuget/Microsoft.NET.Sdk.IL/targets/Microsoft.NET.Sdk.IL.targets
+++ b/src/coreclr/src/.nuget/Microsoft.NET.Sdk.IL/targets/Microsoft.NET.Sdk.IL.targets
@@ -7,7 +7,7 @@ WARNING:  DO NOT MODIFY this file unless you are knowledgeable about MSBuild and
           created a backup copy.  Incorrect changes to this file will make it
           impossible to load or build your projects from the command-line or the IDE.
 
-Copyright (c) .NET Foundation. All rights reserved. 
+Copyright (c) .NET Foundation. All rights reserved.
 ***********************************************************************************************
 -->
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
@@ -24,13 +24,15 @@ Copyright (c) .NET Foundation. All rights reserved.
     <_OSPlatform Condition="$([MSBuild]::IsOSPlatform('linux'))">linux</_OSPlatform>
     <_OSPlatform Condition="$([MSBuild]::IsOSPlatform('osx'))">osx</_OSPlatform>
     <_OSPlatform Condition="$([MSBuild]::IsOSPlatform('freebsd'))">freebsd</_OSPlatform>
+    <_OSPlatform Condition="$([MSBuild]::IsOSPlatform('netbsd'))">netbsd</_OSPlatform>
+    <_OSPlatform Condition="$([MSBuild]::IsOSPlatform('sunos'))">sunos</_OSPlatform>
     <_OSArchitecture>$([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture)</_OSArchitecture>
 
     <MicrosoftNetCoreIlasmPackageRuntimeId Condition="'$(MicrosoftNetCoreIlasmPackageRuntimeId)' == ''">$(_OSPlatform)-$(_OSArchitecture.ToLower())</MicrosoftNetCoreIlasmPackageRuntimeId>
     <MicrosoftNETCoreILAsmVersion Condition="'$(MicrosoftNETCoreILAsmVersion)' == ''">5.0.0</MicrosoftNETCoreILAsmVersion>
     <MicrosoftNetCoreIlasmPackageName>runtime.$(MicrosoftNetCoreIlasmPackageRuntimeId).microsoft.netcore.ilasm</MicrosoftNetCoreIlasmPackageName>
     <MicrosoftNetCoreIldasmPackageName>runtime.$(MicrosoftNetCoreIlasmPackageRuntimeId).microsoft.netcore.ildasm</MicrosoftNetCoreIldasmPackageName>
-    
+
     <!-- If ILAsmToolPath is specified, it will be used and no packages will be restored
          Otherwise packages will be restored and ilasm and ildasm will be referenced from their packages.  -->
     <_IlasmDir Condition="'$(ILAsmToolPath)' != ''">$([MSBuild]::NormalizeDirectory($(ILAsmToolPath)))</_IlasmDir>
@@ -68,8 +70,8 @@ Copyright (c) .NET Foundation. All rights reserved.
   </Target>
 
   <!-- projects can define an ILResourceReference and we'll decompile it to get native resources -->
-  <Target Name="DisassembleIlasmResourceFile" 
-          BeforeTargets="CoreCompile" 
+  <Target Name="DisassembleIlasmResourceFile"
+          BeforeTargets="CoreCompile"
           Condition="'$(OS)'=='Windows_NT'"
           Inputs="@(ILResourceReference)"
           Outputs="$(IntermediateOutputPath)$(MSBuildProjectName).ref.res.obj">
@@ -122,7 +124,7 @@ Copyright (c) .NET Foundation. All rights reserved.
 
       <_KeyFileArgument Condition="'$(KeyOriginatorFile)' != ''">-KEY="$(KeyOriginatorFile)"</_KeyFileArgument>
 
-      <_IlasmSwitches>-QUIET -NOLOGO</_IlasmSwitches> 
+      <_IlasmSwitches>-QUIET -NOLOGO</_IlasmSwitches>
       <_IlasmSwitches Condition="'$(FoldIdenticalMethods)' == 'True'">$(_IlasmSwitches) -FOLD</_IlasmSwitches>
       <_IlasmSwitches Condition="'$(SizeOfStackReserve)' != ''">$(_IlasmSwitches) -STACK=$(SizeOfStackReserve)</_IlasmSwitches>
       <_IlasmSwitches Condition="'$(DebugType)' == 'Full'">$(_IlasmSwitches) -DEBUG</_IlasmSwitches>
diff --git a/src/coreclr/src/dlls/mscoree/coreclr/CMakeLists.txt b/src/coreclr/src/dlls/mscoree/coreclr/CMakeLists.txt
index 4358d79669b452..4260ea92d19166 100644
--- a/src/coreclr/src/dlls/mscoree/coreclr/CMakeLists.txt
+++ b/src/coreclr/src/dlls/mscoree/coreclr/CMakeLists.txt
@@ -61,10 +61,10 @@ else(CLR_CMAKE_HOST_WIN32)
         set(EXPORTS_LINKER_OPTION "${EXPORTS_LINKER_OPTION} -Wl,--no-warn-shared-textrel")
     endif(CLR_CMAKE_TARGET_ANDROID AND CLR_CMAKE_HOST_ARCH_ARM)
 
-    if(CLR_CMAKE_HOST_SUNOS)
+    if(CLR_CMAKE_TARGET_SUNOS)
         # Add linker exports file option
         set(EXPORTS_LINKER_OPTION -Wl,-M,${EXPORTS_FILE})
-    endif(CLR_CMAKE_HOST_SUNOS)
+    endif(CLR_CMAKE_TARGET_SUNOS)
 
 endif (CLR_CMAKE_HOST_WIN32)
 
diff --git a/src/coreclr/src/inc/pedecoder.h b/src/coreclr/src/inc/pedecoder.h
index ad0e77e532c157..c4f4e92b6b613a 100644
--- a/src/coreclr/src/inc/pedecoder.h
+++ b/src/coreclr/src/inc/pedecoder.h
@@ -95,6 +95,8 @@ inline CHECK CheckOverflow(RVA value1, COUNT_T value2)
 #define IMAGE_FILE_MACHINE_NATIVE_OS_OVERRIDE 0x7B79
 #elif defined(__NetBSD__)
 #define IMAGE_FILE_MACHINE_NATIVE_OS_OVERRIDE 0x1993
+#elif defined(__sun)
+#define IMAGE_FILE_MACHINE_NATIVE_OS_OVERRIDE 0x1992
 #else
 #define IMAGE_FILE_MACHINE_NATIVE_OS_OVERRIDE 0
 #endif
diff --git a/src/coreclr/src/jit/CMakeLists.txt b/src/coreclr/src/jit/CMakeLists.txt
index 8ba2c47973fde4..0fd69af5982090 100644
--- a/src/coreclr/src/jit/CMakeLists.txt
+++ b/src/coreclr/src/jit/CMakeLists.txt
@@ -325,7 +325,7 @@ else()
     set(JIT_EXPORTS_LINKER_OPTION -Wl,--version-script=${JIT_EXPORTS_FILE})
   elseif(CLR_CMAKE_TARGET_OSX)
     set(JIT_EXPORTS_LINKER_OPTION -Wl,-exported_symbols_list,${JIT_EXPORTS_FILE})
-  elseif(CLR_CMAKE_HOST_SUNOS)
+  elseif(CLR_CMAKE_TARGET_SUNOS)
     # Add linker exports file option
     set(JIT_EXPORTS_LINKER_OPTION -Wl,-M,${JIT_EXPORTS_FILE})
   endif()
diff --git a/src/coreclr/src/pal/tests/palsuite/exception_handling/pal_sxs/test1/CMakeLists.txt b/src/coreclr/src/pal/tests/palsuite/exception_handling/pal_sxs/test1/CMakeLists.txt
index 37ff7de67a1fc0..2d2d037ca29c69 100644
--- a/src/coreclr/src/pal/tests/palsuite/exception_handling/pal_sxs/test1/CMakeLists.txt
+++ b/src/coreclr/src/pal/tests/palsuite/exception_handling/pal_sxs/test1/CMakeLists.txt
@@ -26,10 +26,10 @@ if(CLR_CMAKE_TARGET_OSX)
     set(EXPORTS_LINKER_OPTION1 -Wl,-exported_symbols_list,${EXPORTS_FILE1})
 endif(CLR_CMAKE_TARGET_OSX)
 
-if(CLR_CMAKE_HOST_SUNOS)
+if(CLR_CMAKE_TARGET_SUNOS)
     # Add linker exports file option
     set(EXPORTS_LINKER_OPTION -Wl,-M,${EXPORTS_FILE})
-endif(CLR_CMAKE_HOST_SUNOS)
+endif(CLR_CMAKE_TARGET_SUNOS)
 
 set(DLL1SOURCES dlltest1.cpp)
 add_library(paltest_pal_sxs_test1_dll1 SHARED ${DLL1SOURCES})
diff --git a/src/coreclr/src/tools/Common/Compiler/DependencyAnalysis/Target_X64/TargetRegisterMap.cs b/src/coreclr/src/tools/Common/Compiler/DependencyAnalysis/Target_X64/TargetRegisterMap.cs
index 808f8ed03c5836..7d76bf5259b78c 100644
--- a/src/coreclr/src/tools/Common/Compiler/DependencyAnalysis/Target_X64/TargetRegisterMap.cs
+++ b/src/coreclr/src/tools/Common/Compiler/DependencyAnalysis/Target_X64/TargetRegisterMap.cs
@@ -34,6 +34,8 @@ public TargetRegisterMap(TargetOS os)
                 case TargetOS.Linux:
                 case TargetOS.OSX:
                 case TargetOS.FreeBSD:
+                case TargetOS.SunOS:
+                case TargetOS.NetBSD:
                     Arg0 = Register.RDI;
                     Arg1 = Register.RSI;
                     Arg2 = Register.RDX;
diff --git a/src/coreclr/src/tools/Common/TypeSystem/Common/TargetDetails.cs b/src/coreclr/src/tools/Common/TypeSystem/Common/TargetDetails.cs
index 162df18395aab2..9337d7670904aa 100644
--- a/src/coreclr/src/tools/Common/TypeSystem/Common/TargetDetails.cs
+++ b/src/coreclr/src/tools/Common/TypeSystem/Common/TargetDetails.cs
@@ -31,6 +31,7 @@ public enum TargetOS
         OSX,
         FreeBSD,
         NetBSD,
+        SunOS,
         WebAssembly,
     }
 
diff --git a/src/coreclr/src/tools/crossgen2/ILCompiler.ReadyToRun/ObjectWriter/TargetExtensions.cs b/src/coreclr/src/tools/crossgen2/ILCompiler.ReadyToRun/ObjectWriter/TargetExtensions.cs
index d4ba4683609c2e..0b943d6233991c 100644
--- a/src/coreclr/src/tools/crossgen2/ILCompiler.ReadyToRun/ObjectWriter/TargetExtensions.cs
+++ b/src/coreclr/src/tools/crossgen2/ILCompiler.ReadyToRun/ObjectWriter/TargetExtensions.cs
@@ -20,6 +20,7 @@ public enum MachineOSOverride : ushort
         Apple = 0x4644,
         FreeBSD = 0xADC4,
         NetBSD = 0x1993,
+        SunOS = 0x1992,
     }
 
     /// <summary>
diff --git a/src/coreclr/src/tools/crossgen2/ILCompiler.Reflection.ReadyToRun/ReadyToRunReader.cs b/src/coreclr/src/tools/crossgen2/ILCompiler.Reflection.ReadyToRun/ReadyToRunReader.cs
index c252c306d46a04..729a492215755a 100644
--- a/src/coreclr/src/tools/crossgen2/ILCompiler.Reflection.ReadyToRun/ReadyToRunReader.cs
+++ b/src/coreclr/src/tools/crossgen2/ILCompiler.Reflection.ReadyToRun/ReadyToRunReader.cs
@@ -31,6 +31,7 @@ public enum OperatingSystem
         FreeBSD = 0xADC4,
         Linux = 0x7B79,
         NetBSD = 0x1993,
+        SunOS = 0x1992,
         Windows = 0,
         Unknown = -1
     }
diff --git a/src/coreclr/tests/scripts/run-corefx-tests.sh b/src/coreclr/tests/scripts/run-corefx-tests.sh
index 03d186f04c9d5e..39a87d03834d23 100755
--- a/src/coreclr/tests/scripts/run-corefx-tests.sh
+++ b/src/coreclr/tests/scripts/run-corefx-tests.sh
@@ -16,7 +16,7 @@ usage()
     echo "Flavor/OS/Architecture options:"
     echo "    --configuration <config>     Configuration to run (Debug/Release)"
     echo "                                      default: Debug"
-    echo "    --os <os>                         OS to run (FreeBSD, Linux, NetBSD or OSX)"
+    echo "    --os <os>                         OS to run (FreeBSD, Linux, NetBSD, OSX, SunOS)"
     echo "                                      default: detect current OS"
     echo "    --arch <Architecture>             Architecture to run (x64, arm, armel, x86, arm64)"
     echo "                                      default: detect current architecture"
@@ -37,7 +37,7 @@ usage()
     echo "Runtime Code Coverage options:"
     echo "    --coreclr-coverage                Optional argument to get coreclr code coverage reports"
     echo "    --coreclr-objs <location>         Location of root of the object directory"
-    echo "                                      containing the FreeBSD, Linux, NetBSD or OSX coreclr build"
+    echo "                                      containing the FreeBSD, Linux, NetBSD, OSX or SunOS coreclr build"
     echo "                                      default: <repo_root>/bin/obj/<OS>.x64.<Configuration"
     echo "    --coreclr-src <location>          Location of root of the directory"
     echo "                                      containing the coreclr source files"
@@ -81,6 +81,10 @@ case $OSName in
         OS=NetBSD
         ;;
 
+    SunOS)
+        OS=SunOS
+        ;;
+
     *)
         echo "Unsupported OS $OSName detected, configuring as if for Linux"
         OS=Linux
@@ -342,7 +346,7 @@ run_test()
 
 coreclr_code_coverage()
 {
-    if [ ! "$OS" == "FreeBSD" ] && [ ! "$OS" == "Linux" ] && [ ! "$OS" == "NetBSD" ] && [ ! "$OS" == "OSX" ] ; then
+    if [ "$OS" != "FreeBSD" ] && [ "$OS" != "Linux" ] && [ "$OS" != "NetBSD" ] && [ "$OS" != "OSX" ]  && [ "$OS" != "SunOS" ] ; then
         echo "error: Code Coverage not supported on $OS"
         exit 1
     fi
@@ -501,9 +505,9 @@ then
     exit 1
 fi
 
-if [ ! "$OS" == "FreeBSD" ] && [ ! "$OS" == "Linux" ] && [ ! "$OS" == "NetBSD" ] && [ ! "$OS" == "OSX" ]
+if [ "$OS" != "FreeBSD" ] && [ "$OS" != "Linux" ] && [ "$OS" != "NetBSD" ] && [ "$OS" != "OSX" ] && [ "$OS" != "SunOS" ]
 then
-    echo "error: OS should be FreeBSD, Linux, NetBSD or OSX"
+    echo "error: OS should be FreeBSD, Linux, NetBSD, OSX or SunOS"
     exit 1
 fi
 
diff --git a/src/coreclr/tests/scripts/run-gc-reliability-framework.sh b/src/coreclr/tests/scripts/run-gc-reliability-framework.sh
index 8f8886a1bc84dd..c136c1561ec9ca 100755
--- a/src/coreclr/tests/scripts/run-gc-reliability-framework.sh
+++ b/src/coreclr/tests/scripts/run-gc-reliability-framework.sh
@@ -18,6 +18,9 @@ case $OSName in
         OS=NetBSD
         ;;
 
+    SunOS)
+        OS=SunOS
+        ;;
     *)
         echo "Unsupported OS $OSName detected, configuring as if for Linux"
         OS=Linux
diff --git a/src/coreclr/tests/setup-stress-dependencies.sh b/src/coreclr/tests/setup-stress-dependencies.sh
index 400a78003f6d53..a81c8fff7b2a75 100755
--- a/src/coreclr/tests/setup-stress-dependencies.sh
+++ b/src/coreclr/tests/setup-stress-dependencies.sh
@@ -82,7 +82,7 @@ if [ -z "$libInstallDir" ]; then
     exit_with_error 1
 fi
 
-if [ "$__BuildArch" == "arm64" ] || [ "$__BuildArch" == "arm" ]; then
+if [ "$__BuildArch" = "arm64" ] || [ "$__BuildArch" = "arm" ]; then
     echo "No runtime dependencies for arm32/arm64"
     exit $EXIT_CODE_SUCCESS
 fi
diff --git a/src/coreclr/tests/src/Directory.Build.props b/src/coreclr/tests/src/Directory.Build.props
index fd07aff01d369e..c4ed9921bd310a 100644
--- a/src/coreclr/tests/src/Directory.Build.props
+++ b/src/coreclr/tests/src/Directory.Build.props
@@ -91,6 +91,20 @@
         <TestNugetRuntimeId>ubuntu.14.04-$(TargetArchitecture)</TestNugetRuntimeId>
       </PropertyGroup>
     </When>
+    <When Condition="'$(TargetOS)'=='NetBSD'">
+      <PropertyGroup>
+        <TargetsUnix>true</TargetsUnix>
+        <TargetsNetBSD>true</TargetsNetBSD>
+        <TestNugetRuntimeId>ubuntu.14.04-$(TargetArchitecture)</TestNugetRuntimeId>
+      </PropertyGroup>
+    </When>
+    <When Condition="'$(TargetOS)'=='SunOS'">
+      <PropertyGroup>
+        <TargetsUnix>true</TargetsUnix>
+        <TargetsSunOS>true</TargetsSunOS>
+        <TestNugetRuntimeId>ubuntu.14.04-$(TargetArchitecture)</TestNugetRuntimeId>
+      </PropertyGroup>
+    </When>
   </Choose>
 
   <PropertyGroup>
@@ -109,7 +123,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <TargetsUnknownUnix Condition="'$(TargetsUnix)' == 'true' AND '$(TargetOS)' != 'FreeBSD' AND '$(TargetOS)' != 'Linux' AND '$(TargetOS)' != 'OSX'">true</TargetsUnknownUnix>
+    <TargetsUnknownUnix Condition="'$(TargetsUnix)' == 'true' AND '$(TargetOS)' != 'FreeBSD' AND '$(TargetOS)' != 'Linux' AND '$(TargetOS)' != 'NetBSD' AND '$(TargetOS)' != 'OSX' AND '$(TargetOS)' != 'SunOS'">true</TargetsUnknownUnix>
     <Language Condition="'$(Language)' == '' and  '$(MSBuildProjectExtension)' == '.csproj'">C#</Language>
     <Language Condition="'$(Language)' == '' and  '$(MSBuildProjectExtension)' == '.ilproj'">IL</Language>
   </PropertyGroup>
diff --git a/src/coreclr/tests/src/JIT/Directed/StructABI/StructABI.csproj b/src/coreclr/tests/src/JIT/Directed/StructABI/StructABI.csproj
index d43bf082a225b5..440413d3e2853b 100644
--- a/src/coreclr/tests/src/JIT/Directed/StructABI/StructABI.csproj
+++ b/src/coreclr/tests/src/JIT/Directed/StructABI/StructABI.csproj
@@ -16,7 +16,7 @@
   <ItemGroup>
     <Compile Include="StructABI.cs" />
     <Compile Include="StructABI.Windows.cs" Condition="'$(TargetOS)' == 'Windows_NT'" />
-    <Compile Include="StructABI.Unix.cs" Condition="'$(TargetOS)' == 'Linux' Or '$(TargetOS)' == 'FreeBSD'" />
+    <Compile Include="StructABI.Unix.cs" Condition="'$(TargetOS)' == 'Linux' Or '$(TargetOS)' == 'FreeBSD' Or '$(TargetOS)' == 'SunOS'" />
     <Compile Include="StructABI.OSX.cs" Condition="'$(TargetOS)' == 'OSX'" />
   </ItemGroup>
   <ItemGroup>