diff --git a/docs/workflow/building/libraries/freebsd-instructions.md b/docs/workflow/building/libraries/freebsd-instructions.md
index 1ee100dfd62978..09008a4f49c49b 100644
--- a/docs/workflow/building/libraries/freebsd-instructions.md
+++ b/docs/workflow/building/libraries/freebsd-instructions.md
@@ -7,7 +7,7 @@ Tested on plain FreeBSD 11.3 Azure image
 ## Prerequisites
 This needs to be done once on fresh system.
 
-```sudo pkg install cmake git icu libunwind bash python2 krb5 lttng-ust llvm60 libgit2```
+```sudo pkg install cmake git icu libunwind bash python2 krb5 lttng-ust llvm90 libgit2 libinotify openssl```
 
 some scripts may still assume /bin/bash exists. To workaround it for now do of needed:
 ```
diff --git a/eng/native/build-commons.sh b/eng/native/build-commons.sh
index 53be70562aaff0..9c93eb9bd81e55 100755
--- a/eng/native/build-commons.sh
+++ b/eng/native/build-commons.sh
@@ -204,6 +204,7 @@ __BuildArch=$arch
 __HostArch=$arch
 __TargetOS=$os
 __HostOS=$os
+__BuildOS=$os
 
 __msbuildonunsupportedplatform=0
 
diff --git a/eng/native/configurecompiler.cmake b/eng/native/configurecompiler.cmake
index a31b7b168c6163..a4c66676e3214f 100644
--- a/eng/native/configurecompiler.cmake
+++ b/eng/native/configurecompiler.cmake
@@ -182,7 +182,7 @@ if(CLR_CMAKE_HOST_LINUX)
 endif(CLR_CMAKE_HOST_LINUX)
 if(CLR_CMAKE_HOST_FREEBSD)
   add_compile_options($<$<COMPILE_LANGUAGE:ASM>:-Wa,--noexecstack>)
-  add_link_options(-fuse-ld=lld LINKER:--build-id=sha1)
+  add_link_options(LINKER:--build-id=sha1)
 endif(CLR_CMAKE_HOST_FREEBSD)
 
 #------------------------------------
diff --git a/eng/native/init-distro-rid.sh b/eng/native/init-distro-rid.sh
index 310e1c4f8ea64b..fdb332afc6e427 100644
--- a/eng/native/init-distro-rid.sh
+++ b/eng/native/init-distro-rid.sh
@@ -20,14 +20,6 @@
 # If -portablebuild=false is passed a non-portable rid will be created for any
 # distro.
 #
-# Below is the list of current non-portable platforms.
-#
-# Builds from the following *must* be non-portable:
-#
-#   |    OS     |           Expected RID            |
-#   -------------------------------------------------
-#   |  freeBSD  |        freebsd.(version)-x64      |
-#
 # It is important to note that the function does not return anything, but it
 # exports __DistroRid, if there is a non-portable distro rid to be used.
 #
@@ -70,8 +62,11 @@ initNonPortableDistroRid()
     fi
 
     if [ "$targetOs" = "FreeBSD" ]; then
-        __freebsd_major_version=$(freebsd-version | { read v; echo "${v%%.*}"; })
-        nonPortableBuildID="freebsd.$__freebsd_major_version-${buildArch}"
+        if (( isPortable == 0 )); then
+            # $rootfsDir can be empty. freebsd-version is shell script and it should always work.
+            __freebsd_major_version=$($rootfsDir/bin/freebsd-version | { read v; echo "${v%%.*}"; })
+            nonPortableBuildID="freebsd.$__freebsd_major_version-${buildArch}"
+        fi
     elif getprop ro.product.system.model 2>&1 | grep -qi android; then
         __android_sdk_version=$(getprop ro.build.version.sdk)
         nonPortableBuildID="android.$__android_sdk_version-${buildArch}"
diff --git a/src/coreclr/crossgen-corelib.proj b/src/coreclr/crossgen-corelib.proj
index 08e7e52b1201d6..6551f5db6ba267 100644
--- a/src/coreclr/crossgen-corelib.proj
+++ b/src/coreclr/crossgen-corelib.proj
@@ -6,6 +6,7 @@
     <ItemGroup>
       <_CoreClrBuildArg Condition="'$(TargetArchitecture)' != ''" Include="-$(TargetArchitecture)" />
       <_CoreClrBuildArg Include="-$(Configuration.ToLower())" />
+      <_CoreClrBuildArg Include="-os $(TargetOS)" />
     </ItemGroup>
 
     <PropertyGroup>
diff --git a/src/coreclr/crossgen-corelib.sh b/src/coreclr/crossgen-corelib.sh
index 570f22db10511e..73811315afefa0 100755
--- a/src/coreclr/crossgen-corelib.sh
+++ b/src/coreclr/crossgen-corelib.sh
@@ -94,7 +94,7 @@ __UnprocessedBuildArgs=
 
 source "$__ProjectRoot"/_build-commons.sh
 
-if [[ "${__BuildArch}" != "${__HostArch}" ]]; then
+if [[ "${__BuildArch}" != "${__HostArch}" ]] || [[ "$__BuildOS" != "$__TargetOS" ]]; then
     __CrossBuild=1
 fi
 
diff --git a/src/coreclr/runtime.proj b/src/coreclr/runtime.proj
index c36ed54bc80cf3..344d76b2f28fef 100644
--- a/src/coreclr/runtime.proj
+++ b/src/coreclr/runtime.proj
@@ -10,6 +10,8 @@
       <_CoreClrBuildArg Include="$(Compiler)" />
       <_CoreClrBuildArg Condition="'$(ContinuousIntegrationBuild)' == 'true'" Include="-ci" />
       <_CoreClrBuildArg Condition="'$(CrossBuild)' == 'true'" Include="-cross" />
+      <_CoreClrBuildArg Include="-os $(TargetOS)" />
+
       <_CoreClrBuildArg Condition="$([MSBuild]::IsOsPlatform(Windows)) and ('$(TargetArchitecture)' == 'x86' or '$(TargetArchitecture)' == 'x64') and '$(Configuration)' == 'Release'" Include="-enforcepgo" />
       <_CoreClrBuildArg Condition="$([MSBuild]::IsOsPlatform(Windows)) and '$(CrossDac)' != ''" Include="-$(CrossDac)dac" />
       <_CoreClrBuildArg Condition="'$(OfficialBuildId)' != ''" Include="/p:OfficialBuildId=$(OfficialBuildId)" />
diff --git a/src/coreclr/src/pal/src/CMakeLists.txt b/src/coreclr/src/pal/src/CMakeLists.txt
index 093d7d9b79df35..e7c1629d5b263f 100644
--- a/src/coreclr/src/pal/src/CMakeLists.txt
+++ b/src/coreclr/src/pal/src/CMakeLists.txt
@@ -5,6 +5,8 @@ endif(CLR_CMAKE_TARGET_OSX OR CLR_CMAKE_TARGET_FREEBSD)
 
 if(NOT DEFINED ENV{ROOTFS_DIR})
   include_directories(SYSTEM /usr/local/include)
+elseif (CLR_CMAKE_TARGET_FREEBSD)
+  include_directories(SYSTEM $ENV{ROOTFS_DIR}/usr/local/include)
 endif()
 
 if(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND)
diff --git a/src/coreclr/src/pal/src/configure.cmake b/src/coreclr/src/pal/src/configure.cmake
index 048139971879df..62e5690af32037 100644
--- a/src/coreclr/src/pal/src/configure.cmake
+++ b/src/coreclr/src/pal/src/configure.cmake
@@ -8,7 +8,7 @@ include(CheckTypeSize)
 include(CheckLibraryExists)
 
 if(CLR_CMAKE_TARGET_FREEBSD)
-  set(CMAKE_REQUIRED_INCLUDES /usr/local/include)
+  set(CMAKE_REQUIRED_INCLUDES ${CROSS_ROOTFS}/usr/local/include)
 elseif(CLR_CMAKE_TARGET_SUNOS)
   set(CMAKE_REQUIRED_INCLUDES /opt/local/include)
 endif()
diff --git a/src/coreclr/tryrun.cmake b/src/coreclr/tryrun.cmake
index f841f56b83b49d..5fdc28a4f204e9 100644
--- a/src/coreclr/tryrun.cmake
+++ b/src/coreclr/tryrun.cmake
@@ -12,9 +12,16 @@ if(EXISTS ${CROSS_ROOTFS}/usr/lib/gcc/armv6-alpine-linux-musleabihf OR
    SET(ALPINE_LINUX 1)
 else()
    SET(ALPINE_LINUX 0)
+   if(EXISTS ${CROSS_ROOTFS}/bin/freebsd-version)
+       set(FREEBSD 1)
+       set(CMAKE_SYSTEM_NAME FreeBSD)
+       set(CLR_CMAKE_TARGET_OS FreeBSD)
+   else()
+       SET(FREEBSD 0)
+   endif()
 endif()
 
-if(TARGET_ARCH_NAME MATCHES "^(armel|arm|arm64|x86)$")
+if(TARGET_ARCH_NAME MATCHES "^(armel|arm|arm64|x86)$" OR FREEBSD)
   set_cache_value(FILE_OPS_CHECK_FERROR_OF_PREVIOUS_CALL_EXITCODE 1)
   set_cache_value(GETPWUID_R_SETS_ERRNO_EXITCODE 0)
   set_cache_value(HAS_POSIX_SEMAPHORES_EXITCODE 0)
@@ -57,6 +64,16 @@ if(TARGET_ARCH_NAME MATCHES "^(armel|arm|arm64|x86)$")
     set_cache_value(UNGETC_NOT_RETURN_EOF_EXITCODE 0)
   endif()
 
+  if (FREEBSD)
+    set_cache_value(HAVE_BROKEN_FIFO_KEVENT_EXITCODE 1)
+    set_cache_value(HAVE_PROCFS_MAPS 0)
+    set_cache_value(HAVE_PROCFS_STAT 0)
+    set_cache_value(HAVE_PROCFS_STATUS 0)
+    set_cache_value(GETPWUID_R_SETS_ERRNO 0)
+    set_cache_value(UNGETC_NOT_RETURN_EOF 0)
+    set_cache_value(HAVE_COMPATIBLE_ILOGBNAN 1)
+    set_cache_value(HAVE_FUNCTIONAL_PTHREAD_ROBUST_MUTEXES_EXITCODE 0)
+  endif()
 else()
   message(FATAL_ERROR "Arch is ${TARGET_ARCH_NAME}. Only armel, arm, arm64 and x86 are supported!")
 endif()
diff --git a/src/installer/corehost/build.proj b/src/installer/corehost/build.proj
index 583a24caa31eea..9de06c607f6460 100644
--- a/src/installer/corehost/build.proj
+++ b/src/installer/corehost/build.proj
@@ -27,7 +27,7 @@
     <PropertyGroup>
       <CMakeBuildDir>$(IntermediateOutputRootPath)corehost\cmake\</CMakeBuildDir>
 
-      <BuildArgs>$(Configuration) $(TargetArchitecture) -apphostver "$(AppHostVersion)" -hostver "$(HostVersion)" -fxrver "$(HostResolverVersion)" -policyver "$(HostPolicyVersion)" -commithash "$(LatestCommit)"</BuildArgs>
+      <BuildArgs>$(Configuration) $(TargetArchitecture) -apphostver "$(AppHostVersion)" -hostver "$(HostVersion)" -fxrver "$(HostResolverVersion)" -policyver "$(HostPolicyVersion)" -commithash "$(LatestCommit)" -os $(TargetOS)</BuildArgs>
       <BuildArgs Condition="'$(PortableBuild)' != 'true'">$(BuildArgs) -portablebuild=false</BuildArgs>
       <BuildArgs Condition="'$(CrossBuild)' == 'true'">$(BuildArgs) -cross</BuildArgs>
       <BuildArgs Condition="'$(Compiler)' != ''">$(BuildArgs) $(Compiler)</BuildArgs>
diff --git a/src/libraries/Native/Unix/CMakeLists.txt b/src/libraries/Native/Unix/CMakeLists.txt
index bb4dbcbe05f2af..b3c9613a0e10b0 100644
--- a/src/libraries/Native/Unix/CMakeLists.txt
+++ b/src/libraries/Native/Unix/CMakeLists.txt
@@ -149,7 +149,6 @@ endif ()
 
 if(CLR_CMAKE_TARGET_FREEBSD)
     add_definitions(-D_BSD_SOURCE) # required for getline
-    add_link_options(-fuse-ld=lld)
 endif(CLR_CMAKE_TARGET_FREEBSD)
 
 # CLR_ADDITIONAL_LINKER_FLAGS - used for passing additional arguments to linker
diff --git a/src/libraries/Native/Unix/configure.cmake b/src/libraries/Native/Unix/configure.cmake
index bba87eba0f125b..c97d318fee90a9 100644
--- a/src/libraries/Native/Unix/configure.cmake
+++ b/src/libraries/Native/Unix/configure.cmake
@@ -22,8 +22,8 @@ elseif (CLR_CMAKE_TARGET_IOS)
     set(PAL_UNIX_NAME \"IOS\")
 elseif (CLR_CMAKE_TARGET_FREEBSD)
     set(PAL_UNIX_NAME \"FREEBSD\")
-    include_directories(SYSTEM /usr/local/include)
-    set(CMAKE_REQUIRED_INCLUDES /usr/local/include)
+    include_directories(SYSTEM ${CROSS_ROOTFS}/usr/local/include)
+    set(CMAKE_REQUIRED_INCLUDES ${CROSS_ROOTFS}/usr/local/include)
 elseif (CLR_CMAKE_TARGET_NETBSD)
     set(PAL_UNIX_NAME \"NETBSD\")
 elseif (CLR_CMAKE_TARGET_ARCH_WASM)
@@ -728,12 +728,11 @@ check_symbol_exists(
 
 if(CLR_CMAKE_TARGET_IOS)
     set(HAVE_IOS_NET_ROUTE_H 1)
-    set(NET_ROUTE_H_INCLUDE "${CMAKE_CURRENT_SOURCE_DIR}/System.Native/ios/net/route.h")
+    set(CMAKE_EXTRA_INCLUDE_FILES sys/types.h "${CMAKE_CURRENT_SOURCE_DIR}/System.Native/ios/net/route.h")
 else()
-    set(NET_ROUTE_H_INCLUDE net/route.h)
+    set(CMAKE_EXTRA_INCLUDE_FILES sys/types.h net/if.h net/route.h)
 endif()
 
-set(CMAKE_EXTRA_INCLUDE_FILES sys/types.h ${NET_ROUTE_H_INCLUDE})
 check_type_size(
     "struct rt_msghdr"
      HAVE_RT_MSGHDR
diff --git a/src/libraries/Native/Unix/tryrun.cmake b/src/libraries/Native/Unix/tryrun.cmake
index 9c027966532498..a1d7384f5a9557 100644
--- a/src/libraries/Native/Unix/tryrun.cmake
+++ b/src/libraries/Native/Unix/tryrun.cmake
@@ -1,4 +1,5 @@
 set(TARGET_ARCH_NAME $ENV{TARGET_BUILD_ARCH})
+set(CROSS_ROOTFS $ENV{ROOTFS_DIR})
 
 macro(set_cache_value)
   set(${ARGV0} ${ARGV1} CACHE STRING "Result from TRY_RUN" FORCE)
@@ -9,11 +10,19 @@ if(EXISTS ${CROSS_ROOTFS}/usr/lib/gcc/armv6-alpine-linux-musleabihf OR
    EXISTS ${CROSS_ROOTFS}/usr/lib/gcc/aarch64-alpine-linux-musl)
   
    SET(ALPINE_LINUX 1)
+   SET(FREEBSD 0)
 else()
    SET(ALPINE_LINUX 0)
+   if(EXISTS ${CROSS_ROOTFS}/bin/freebsd-version)
+       set(FREEBSD 1)
+       set(CMAKE_SYSTEM_NAME FreeBSD)
+       set(CLR_CMAKE_TARGET_OS FreeBSD)
+   else()
+       SET(FREEBSD 0)
+   endif()
 endif()
 
-if(TARGET_ARCH_NAME MATCHES "^(armel|arm|arm64|x86)$")
+if(TARGET_ARCH_NAME MATCHES "^(armel|arm|arm64|x86)$" OR FREEBSD)
   set_cache_value(HAVE_CLOCK_MONOTONIC_EXITCODE 0)
   set_cache_value(HAVE_CLOCK_REALTIME_EXITCODE 0)
 
@@ -22,6 +31,11 @@ if(TARGET_ARCH_NAME MATCHES "^(armel|arm|arm64|x86)$")
   else()
     set_cache_value(HAVE_SHM_OPEN_THAT_WORKS_WELL_ENOUGH_WITH_MMAP_EXITCODE 0)
   endif()
+  if (FREEBSD)
+    set_cache_value(HAVE_SHM_OPEN_THAT_WORKS_WELL_ENOUGH_WITH_MMAP 1)
+    set_cache_value(HAVE_CLOCK_MONOTONIC 1)
+    set_cache_value(HAVE_CLOCK_REALTIME 1)
+  endif()
 else()
   message(FATAL_ERROR "Arch is ${TARGET_ARCH_NAME}. Only armel, arm, arm64 and x86 are supported!")
 endif()