diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -415,6 +415,9 @@
 set(LIBCXX_INSTALL_RUNTIME_DIR "${CMAKE_INSTALL_BINDIR}" CACHE PATH
     "Path where built libc++ runtime libraries should be installed.")
 
+set(LIBCXX_SHARED_OUTPUT_NAME "c++" CACHE STRING
+    "Output name for the shared libc++ runtime library.")
+
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
   set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
@@ -457,6 +460,10 @@
 set(LIBCXX_COMPILE_FLAGS "")
 set(LIBCXX_LINK_FLAGS "")
 set(LIBCXX_LIBRARIES "")
+set(LIBCXX_ADDITIONAL_COMPILE_FLAGS "" CACHE STRING
+    "Additional Compile only flags which can be provided in cache")
+set(LIBCXX_ADDITIONAL_LIBRARIES "" CACHE STRING
+    "Additional libraries libc++ is linked to which can be provided in cache")
 
 # Include macros for adding and removing libc++ flags.
 include(HandleLibcxxFlags)
@@ -465,14 +472,13 @@
 # These flags get added to CMAKE_CXX_FLAGS and CMAKE_C_FLAGS so that
 # 'config-ix' use them during feature checks. It also adds them to both
 # 'LIBCXX_COMPILE_FLAGS' and 'LIBCXX_LINK_FLAGS'
-if(ZOS)
-  add_target_flags_if_supported("-fzos-le-char-mode=ebcdic")
-endif()
 
 if (${CMAKE_SYSTEM_NAME} MATCHES "AIX")
   add_target_flags_if_supported("-mdefault-visibility-export-mapping=explicit")
   set(CMAKE_AIX_EXPORT_ALL_SYMBOLS OFF)
 endif()
+add_compile_flags("${LIBCXX_ADDITIONAL_COMPILE_FLAGS}")
+add_library_flags("${LIBCXX_ADDITIONAL_LIBRARIES}")
 
 # Configure compiler.
 include(config-ix)
diff --git a/libcxx/cmake/caches/s390x-ibm-zos-ascii.cmake b/libcxx/cmake/caches/s390x-ibm-zos-ascii.cmake
new file mode 100644
--- /dev/null
+++ b/libcxx/cmake/caches/s390x-ibm-zos-ascii.cmake
@@ -0,0 +1,22 @@
+# Common
+set(CMAKE_BUILD_TYPE Release CACHE STRING "")
+
+set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
+set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
+set(LIBCXX_ENABLE_STATIC OFF CACHE BOOL "")
+set(LIBCXX_INCLUDE_TESTS OFF CACHE BOOL "")
+set(LIBCXX_INSTALL_HEADERS OFF CACHE BOOL "")
+set(LIBCXX_INCLUDE_BENCHMARKS OFF CACHE BOOL "")
+
+set(LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
+set(LIBCXXABI_ENABLE_STATIC OFF CACHE BOOL "")
+set(LIBCXXABI_INCLUDE_TESTS OFF CACHE BOOL "")
+
+# Target Specific
+set(LIBCXX_DLL_NAME CRTEQCXS CACHE STRING "")
+set(LIBCXX_SHARED_OUTPUT_NAME "c++_a" CACHE STRING
+    "Output name for the shared libc++ runtime library.")
+set(LIBCXX_CXX_ABI system-libcxxabi CACHE STRING "")
+
+set(LIBCXX_ADDITIONAL_COMPILE_FLAGS "-fzos-le-char-mode=ascii" CACHE STRING "")
+set(LIBCXX_ADDITIONAL_LIBRARIES "-L../s390x-ibm-zos/lib -Wl,../s390x-ibm-zos/lib/libunwind.x" CACHE STRING "")
diff --git a/libcxx/cmake/caches/s390x-ibm-zos.cmake b/libcxx/cmake/caches/s390x-ibm-zos.cmake
new file mode 100644
--- /dev/null
+++ b/libcxx/cmake/caches/s390x-ibm-zos.cmake
@@ -0,0 +1,19 @@
+set(CMAKE_BUILD_TYPE Release CACHE STRING "")
+
+# Common
+set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
+set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
+set(LIBCXX_ENABLE_STATIC OFF CACHE BOOL "")
+set(LIBCXX_INCLUDE_TESTS ON CACHE BOOL "")
+
+set(LIBCXXABI_ENABLE_SHARED ON CACHE BOOL "")
+set(LIBCXXABI_ENABLE_STATIC OFF CACHE BOOL "")
+set(LIBCXXABI_INCLUDE_TESTS ON CACHE BOOL "")
+
+# Target Specific
+set(LIBCXX_DLL_NAME CRTEQCXE CACHE STRING "")
+
+set(LIBCXXABI_DLL_NAME CRTEQCXA CACHE STRING "")
+
+set(LLVM_EXTERNAL_UNWIND_SOURCE_DIR "$ENV{LLVM_BASE}/zos-unwind" CACHE PATH "The path to the external unwind source directory.")
+set(LIBCXXABI_ADDITIONAL_LIBRARIES "-Wl,lib/libunwind.x" CACHE STRING "")
diff --git a/libcxx/cmake/caches/s390x32-ibm-zos-ascii.cmake b/libcxx/cmake/caches/s390x32-ibm-zos-ascii.cmake
new file mode 100644
--- /dev/null
+++ b/libcxx/cmake/caches/s390x32-ibm-zos-ascii.cmake
@@ -0,0 +1,22 @@
+# Common
+set(CMAKE_BUILD_TYPE Release CACHE STRING "")
+
+set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
+set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
+set(LIBCXX_ENABLE_STATIC OFF CACHE BOOL "")
+set(LIBCXX_INCLUDE_TESTS OFF CACHE BOOL "")
+set(LIBCXX_INSTALL_HEADERS OFF CACHE BOOL "")
+set(LIBCXX_INCLUDE_BENCHMARKS OFF CACHE BOOL "")
+
+set(LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
+set(LIBCXXABI_ENABLE_STATIC OFF CACHE BOOL "")
+set(LIBCXXABI_INCLUDE_TESTS OFF CACHE BOOL "")
+
+# Target Specific
+set(LIBCXX_DLL_NAME CRTEHCXS CACHE STRING "")
+set(LIBCXX_SHARED_OUTPUT_NAME "c++_a" CACHE STRING
+    "Output name for the shared libc++ runtime library.")
+set(LIBCXX_CXX_ABI system-libcxxabi CACHE STRING "")
+
+set(LIBCXX_ADDITIONAL_COMPILE_FLAGS "-fzos-le-char-mode=ascii" CACHE STRING "")
+set(LIBCXX_ADDITIONAL_LIBRARIES "-L../s390x-ibm-zos/lib -Wl,../s390x32-ibm-zos/lib/libunwind.x" CACHE STRING "")
diff --git a/libcxx/cmake/caches/s390x32-ibm-zos.cmake b/libcxx/cmake/caches/s390x32-ibm-zos.cmake
new file mode 100644
--- /dev/null
+++ b/libcxx/cmake/caches/s390x32-ibm-zos.cmake
@@ -0,0 +1,19 @@
+# Common
+set(CMAKE_BUILD_TYPE Release CACHE STRING "")
+
+set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
+set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
+set(LIBCXX_ENABLE_STATIC OFF CACHE BOOL "")
+set(LIBCXX_INCLUDE_TESTS ON CACHE BOOL "")
+
+set(LIBCXXABI_ENABLE_SHARED ON CACHE BOOL "")
+set(LIBCXXABI_ENABLE_STATIC OFF CACHE BOOL "")
+set(LIBCXXABI_INCLUDE_TESTS ON CACHE BOOL "")
+
+# Target Specific
+set(LIBCXX_DLL_NAME CRTEHCXE CACHE STRING "")
+
+set(LIBCXXABI_DLL_NAME CRTEHCXA CACHE STRING "")
+
+set(LLVM_EXTERNAL_UNWIND_SOURCE_DIR "$ENV{LLVM_BASE}/zos-unwind" CACHE PATH "The path to the external unwind source directory.")
+set(LIBCXXABI_ADDITIONAL_LIBRARIES "-Wl,lib/libunwind.x" CACHE STRING "")
diff --git a/libcxx/docs/BuildingLibcxx.rst b/libcxx/docs/BuildingLibcxx.rst
--- a/libcxx/docs/BuildingLibcxx.rst
+++ b/libcxx/docs/BuildingLibcxx.rst
@@ -287,6 +287,24 @@
   Path where target-specific libc++ headers should be installed. If a relative
   path, relative to ``CMAKE_INSTALL_PREFIX``.
 
+.. option:: LIBCXX_SHARED_OUTPUT_NAME:STRING
+
+  **Default**: ``c++``
+
+  Output name for the shared libc++ runtime library.
+
+.. option:: LIBCXX_ADDITIONAL_COMPILE_FLAGS:STRING
+
+  **Default**: ````
+
+  Additional Compile only flags which can be provided in cache.
+
+.. option:: LIBCXX_ADDITIONAL_LIBRARIES:STRING
+
+  **Default**: ````
+
+  Additional libraries libc++ is linked to which can be provided in cache.
+
 
 .. _ABI Library Specific Options:
 
@@ -330,6 +348,12 @@
   Build and use the LLVM unwinder. Note: This option can only be used when
   libc++abi is the C++ ABI library used.
 
+.. option:: LIBCXXABI_ADDITIONAL_LIBRARIES:STRING
+
+  **Default**: ````
+
+  Additional libraries libc++abi is linked to which can be provided in cache.
+
 
 libc++ Feature Options
 ----------------------
diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -204,7 +204,7 @@
     PROPERTIES
       COMPILE_FLAGS "${LIBCXX_COMPILE_FLAGS}"
       LINK_FLAGS    "${LIBCXX_LINK_FLAGS}"
-      OUTPUT_NAME   "c++"
+      OUTPUT_NAME   "${LIBCXX_SHARED_OUTPUT_NAME}"
       VERSION       "${LIBCXX_LIBRARY_VERSION}"
       SOVERSION     "${LIBCXX_ABI_VERSION}"
       DEFINE_SYMBOL ""
@@ -212,6 +212,16 @@
   cxx_add_common_build_flags(cxx_shared)
   cxx_set_common_defines(cxx_shared)
 
+  if(ZOS)
+    add_custom_command(TARGET cxx_shared POST_BUILD
+      COMMAND
+        ${LIBCXX_SOURCE_DIR}/utils/zos_rename_dll_side_deck.sh
+        $<TARGET_LINKER_FILE_NAME:cxx_shared> $<TARGET_FILE_NAME:cxx_shared> "${LIBCXX_DLL_NAME}"
+      COMMENT "Rename dll name inside the side deck file"
+      WORKING_DIRECTORY $<TARGET_FILE_DIR:cxx_shared>
+    )
+  endif()
+
   # Link against libc++abi
   if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY)
     target_link_libraries(cxx_shared PRIVATE libcxx-abi-shared-objects)
diff --git a/libcxx/utils/zos_rename_dll_side_deck.sh b/libcxx/utils/zos_rename_dll_side_deck.sh
new file mode 100755
--- /dev/null
+++ b/libcxx/utils/zos_rename_dll_side_deck.sh
@@ -0,0 +1,57 @@
+#!/usr/bin/env bash
+#
+# Script to rename DLL name within side deck.
+#
+
+# Stops execution if a command or pipeline has an error.
+set -e
+
+sidedeck=$1
+old_dll_name=$2
+new_dll_name=$3
+
+function error() {
+  printf "ERROR: %s\n" "$*"
+  exit 1
+}
+
+function usage() {
+cat <<EOF
+Usage: $(basename $0) <side deck file> <old dll name> <new dll name>:
+          [-h|--help] Display this help and exit.
+EOF
+}
+
+rename_dll_name_inside_side_deck() {
+
+if [[ -z "$sidedeck" || -z "$old_dll_name" || -z "$new_dll_name" ]]; then
+  usage
+  error "All 3 parameters must be specified."
+fi
+
+[[ -f "$sidedeck" ]] || error "The '$sidedeck' file must exists."
+
+old_len=${#old_dll_name}
+new_len=${#new_dll_name}
+
+if (( $new_len > $old_len )); then
+  error "New DLL name $new_dll_name must have $old_len characters or less."
+fi
+
+if ((padding_len=$old_len-$new_len )); then
+  pad=$(printf "%*s" $padding_len "")
+fi
+
+# Touch the temp. file and set the tag to 1047 first so the redirecting statement
+# will write in 1047 and not 819 encoding.
+touch $sidedeck.tmp; chtag -tc1047 $sidedeck.tmp
+sed "/ IMPORT /s/'$old_dll_name/$pad'$new_dll_name/g" $sidedeck > $sidedeck.tmp
+mv $sidedeck.tmp $sidedeck
+}
+
+function main() {
+  rename_dll_name_inside_side_deck
+}
+
+main "$@"
+
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -228,6 +228,7 @@
 set(LIBCXXABI_COMPILE_FLAGS "")
 set(LIBCXXABI_LINK_FLAGS "")
 set(LIBCXXABI_LIBRARIES "")
+set(LIBCXXABI_ADDITIONAL_LIBRARIES "" CACHE STRING "Additional libraries libc++abi is linked to which can be provided in cache")
 
 # Include macros for adding and removing libc++abi flags.
 include(HandleLibcxxabiFlags)
@@ -245,6 +246,7 @@
   add_target_flags_if_supported("-mdefault-visibility-export-mapping=explicit")
   set(CMAKE_AIX_EXPORT_ALL_SYMBOLS OFF)
 endif()
+add_library_flags("${LIBCXXABI_ADDITIONAL_LIBRARIES}")
 
 # Configure compiler. Must happen after setting the target flags.
 include(config-ix)