diff --git a/Makefile b/Makefile
index 8502e2e..1eb0174 100644
--- a/Makefile
+++ b/Makefile
@@ -39,7 +39,7 @@
 
 MAKE_HELPERS_DIRECTORY := make_helpers/
 include ${MAKE_HELPERS_DIRECTORY}build_macros.mk
-include ${MAKE_HELPERS_DIRECTORY}unix.mk
+include ${MAKE_HELPERS_DIRECTORY}build_env.mk
 
 ################################################################################
 # Default values for build configurations
diff --git a/make_helpers/build_env.mk b/make_helpers/build_env.mk
new file mode 100644
index 0000000..62c7f68
--- /dev/null
+++ b/make_helpers/build_env.mk
@@ -0,0 +1,96 @@
+#
+#  Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions are met:
+#
+#  Redistributions of source code must retain the above copyright notice, this
+#  list of conditions and the following disclaimer.
+#
+#  Redistributions in binary form must reproduce the above copyright notice,
+#  this list of conditions and the following disclaimer in the documentation
+#  and/or other materials provided with the distribution.
+#
+#  Neither the name of ARM nor the names of its contributors may be used
+#  to endorse or promote products derived from this software without specific
+#  prior written permission.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+#  POSSIBILITY OF SUCH DAMAGE.
+#
+
+# This file contains the logic to identify and include any relevant
+# build environment specific make include files.
+
+ifndef BUILD_ENV_MK
+    BUILD_ENV_MK        :=      $(lastword $(MAKEFILE_LIST))
+
+    # Block possible built-in command definitions that are not fully portable.
+    # This traps occurences that need replacing with our OS portable macros
+    COPY                :=      $$(error "Replace COPY with call to SHELL_COPY or SHELL_COPY_TREE.")
+    CP                  :=      $$(error "Replace CP with call to SHELL_COPY or SHELL_COPY_TREE.")
+    DEL                 :=      $$(error "Replace DEL with call to SHELL_DELETE.")
+    MD                  :=      $$(error "Replace MD with call to MAKE_PREREQ_DIR.")
+    MKDIR               :=      $$(error "Replace MKDIR with call to MAKE_PREREQ_DIR.")
+    RD                  :=      $$(error "Replace RD with call to SHELL_REMOVE_DIR.")
+    RM                  :=      $$(error "Replace RM with call to SHELL_DELETE.")
+    RMDIR               :=      $$(error "Replace RMDIR with call to SHELL_REMOVE_DIR.")
+
+    ENV_FILE_TO_INCLUDE := unix.mk
+    ifdef OSTYPE
+        ifneq ($(findstring ${OSTYPE}, cygwin),)
+            ENV_FILE_TO_INCLUDE := cygwin.mk
+        else
+            ifneq ($(findstring ${OSTYPE}, MINGW32 mingw msys),)
+                ENV_FILE_TO_INCLUDE := msys.mk
+            endif
+        endif
+    else
+        ifdef MSYSTEM
+            # Although the MINGW MSYS shell sets OSTYPE as msys in its environment,
+            # it does not appear in the GNU make view of environment variables.
+            # We use MSYSTEM as an alternative, as that is seen by make
+            ifneq ($(findstring ${MSYSTEM}, MINGW32 mingw msys),)
+                OSTYPE ?= msys
+                ENV_FILE_TO_INCLUDE := msys.mk
+            endif
+        else
+            ifdef OS
+                ifneq ($(findstring ${OS}, Windows_NT),)
+                    ENV_FILE_TO_INCLUDE := windows.mk
+                endif
+            endif
+        endif
+    endif
+    include ${MAKE_HELPERS_DIRECTORY}${ENV_FILE_TO_INCLUDE}
+    ENV_FILE_TO_INCLUDE :=
+
+    ifndef SHELL_COPY
+        $(error "SHELL_COPY not defined for build environment.")
+    endif
+    ifndef SHELL_COPY_TREE
+        $(error "SHELL_COPY_TREE not defined for build environment.")
+    endif
+    ifndef SHELL_DELETE_ALL
+        $(error "SHELL_DELETE_ALL not defined for build environment.")
+    endif
+    ifndef SHELL_DELETE
+        $(error "SHELL_DELETE not defined for build environment.")
+    endif
+    ifndef MAKE_PREREQ_DIR
+        $(error "MAKE_PREREQ_DIR not defined for build environment.")
+    endif
+    ifndef SHELL_REMOVE_DIR
+        $(error "SHELL_REMOVE_DIR not defined for build environment.")
+    endif
+
+endif
diff --git a/make_helpers/build_macros.mk b/make_helpers/build_macros.mk
index 42e11b3..5a67c4c 100644
--- a/make_helpers/build_macros.mk
+++ b/make_helpers/build_macros.mk
@@ -291,7 +291,7 @@
 
 # NOTE: The line continuation '\' is required in the next define otherwise we
 # end up with a line-feed characer at the end of the last c filename.
-# Also bare this issue in mind if extending the list of supported filetypes.
+# Also bear this issue in mind if extending the list of supported filetypes.
 define SOURCES_TO_OBJS
         $(notdir $(patsubst %.c,%.o,$(filter %.c,$(1)))) \
         $(notdir $(patsubst %.S,%.o,$(filter %.S,$(1))))
diff --git a/make_helpers/cygwin.mk b/make_helpers/cygwin.mk
new file mode 100644
index 0000000..f99be13
--- /dev/null
+++ b/make_helpers/cygwin.mk
@@ -0,0 +1,40 @@
+#
+# Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# Redistributions of source code must retain the above copyright notice, this
+# list of conditions and the following disclaimer.
+#
+# Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# Neither the name of ARM nor the names of its contributors may be used
+# to endorse or promote products derived from this software without specific
+# prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+#
+
+# OS specific definitions for builds in a Cygwin environment.
+# Cygwin allows us to use unix style commands on a windows platform.
+
+ifndef CYGWIN_MK
+    CYGWIN_MK := $(lastword $(MAKEFILE_LIST))
+
+    include ${MAKE_HELPERS_DIRECTORY}unix.mk
+
+endif
diff --git a/make_helpers/msys.mk b/make_helpers/msys.mk
new file mode 100644
index 0000000..ca0f72b
--- /dev/null
+++ b/make_helpers/msys.mk
@@ -0,0 +1,41 @@
+#
+# Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# Redistributions of source code must retain the above copyright notice, this
+# list of conditions and the following disclaimer.
+#
+# Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# Neither the name of ARM nor the names of its contributors may be used
+# to endorse or promote products derived from this software without specific
+# prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+#
+
+# OS specific definitions for builds in a Mingw32 MSYS environment.
+# Mingw32 allows us to use some unix style commands on a windows platform.
+
+ifndef MSYS_MK
+    MSYS_MK := $(lastword $(MAKEFILE_LIST))
+
+    include ${MAKE_HELPERS_DIRECTORY}unix.mk
+
+endif
+
diff --git a/make_helpers/windows.mk b/make_helpers/windows.mk
new file mode 100644
index 0000000..92cc8f6
--- /dev/null
+++ b/make_helpers/windows.mk
@@ -0,0 +1,93 @@
+#
+# Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# Redistributions of source code must retain the above copyright notice, this
+# list of conditions and the following disclaimer.
+#
+# Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# Neither the name of ARM nor the names of its contributors may be used
+# to endorse or promote products derived from this software without specific
+# prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+#
+
+# OS specific parts for builds in a Windows_NT environment. The
+# environment variable OS is set to Windows_NT on all modern Windows platforms
+
+# Include generic windows command definitions.
+
+ifndef WINDOWS_MK
+    WINDOWS_MK := $(lastword $(MAKEFILE_LIST))
+
+    ECHO_BLANK_LINE := @cmd /c echo.
+
+    DIR_DELIM := $(strip \)
+    PATH_SEP := ;
+
+    # For some Windows native commands there is a problem with the directory delimiter.
+    # Make uses / (slash) and the commands expect \ (backslash)
+    # We have to provide a means of translating these, so we define local functions.
+
+    # ${1} is the file to be copied.
+    # ${2} is the destination file name.
+    define SHELL_COPY
+	$(eval tmp_from_file:=$(subst /,\,${1}))
+	$(eval tmp_to_file:=$(subst /,\,${2}))
+	copy "${tmp_from_file}" "${tmp_to_file}"
+    endef
+
+    # ${1} is the directory to be copied.
+    # ${2} is the destination directory path.
+    define SHELL_COPY_TREE
+	$(eval tmp_from_dir:=$(subst /,\,${1}))
+	$(eval tmp_to_dir:=$(subst /,\,${2}))
+	xcopy /HIVE "${tmp_from_dir}" "${tmp_to_dir}"
+    endef
+
+    # ${1} is the file to be deleted.
+    define SHELL_DELETE
+	$(eval tmp_del_file:=$(subst /,\,${*}))
+	-@if exist $(tmp_del_file)  del /Q $(tmp_del_file)
+    endef
+
+    # ${1} is a space delimited list of files to be deleted.
+    define SHELL_DELETE_ALL
+	$(eval $(foreach filename,$(wildcard ${1}),$(call DELETE_IF_THERE,${filename})))
+    endef
+
+    # ${1} is the directory to be generated.
+    # ${2} is optional, and allows prerequisites to be specified.
+    define MAKE_PREREQ_DIR
+
+${1} : ${2}
+	$(eval tmp_dir:=$(subst /,\,${1}))
+	-@if not exist "$(tmp_dir)"  mkdir "${tmp_dir}"
+
+    endef
+
+    # ${1} is the directory to be removed.
+    define SHELL_REMOVE_DIR
+	$(eval tmp_dir:=$(subst /,\,${1}))
+	-@if exist "$(tmp_dir)"  rd /Q /S "$(tmp_dir)"
+    endef
+
+endif
+
diff --git a/tools/cert_create/Makefile b/tools/cert_create/Makefile
index b19d618..8218ab7 100644
--- a/tools/cert_create/Makefile
+++ b/tools/cert_create/Makefile
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -49,7 +49,7 @@
 
 MAKE_HELPERS_DIRECTORY := ../../make_helpers/
 include ${MAKE_HELPERS_DIRECTORY}build_macros.mk
-include ${MAKE_HELPERS_DIRECTORY}unix.mk
+include ${MAKE_HELPERS_DIRECTORY}build_env.mk
 
 PLATFORM_ROOT		:=	../../plat/
 include ${MAKE_HELPERS_DIRECTORY}plat_helpers.mk
diff --git a/tools/fip_create/Makefile b/tools/fip_create/Makefile
index 9f0bf7a..52e06a7 100644
--- a/tools/fip_create/Makefile
+++ b/tools/fip_create/Makefile
@@ -30,7 +30,7 @@
 
 MAKE_HELPERS_DIRECTORY := ../../make_helpers/
 include ${MAKE_HELPERS_DIRECTORY}build_macros.mk
-include ${MAKE_HELPERS_DIRECTORY}unix.mk
+include ${MAKE_HELPERS_DIRECTORY}build_env.mk
 
 PROJECT = fip_create
 OBJECTS = fip_create.o