diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
index 0259fb7159..66dbc96683 100644
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -6164,6 +6164,80 @@ RELEASE_XCLANG_X64_CC_FLAGS   = -ccc-host-triple x86_64-pc-win32-macho -c    -Os
 *_XCLANG_*_ASLPP_FLAGS      = -x c -E 
 *_XCLANG_*_ASL_FLAGS        =
 
+#
+# XCODE5 support
+#
+
+*_XCODE5_*_*_FAMILY            = GCC
+*_XCODE5_*_*_BUILDRULEFAMILY   = XCODE
+
+*_XCODE5_*_ASL_PATH          = /usr/bin/iasl
+
+*_XCODE5_*_MAKE_PATH        = make
+*_XCODE5_*_DSYMUTIL_PATH    = /usr/bin/dsymutil
+
+  DEBUG_XCODE5_*_MTOC_FLAGS = -align 0x20 -d $(DEBUG_DIR)/$(MODULE_NAME).dll
+  NOOPT_XCODE5_*_MTOC_FLAGS = -align 0x20 -d $(DEBUG_DIR)/$(MODULE_NAME).dll
+RELEASE_XCODE5_*_MTOC_FLAGS = -align 0x20 
+
+#
+# use xcode-select to change Xcode version of command line tools
+#
+*_XCODE5_*_CC_PATH      = clang
+*_XCODE5_*_SLINK_PATH   = libtool
+*_XCODE5_*_DLINK_PATH   = ld
+*_XCODE5_*_ASM_PATH     = as
+*_XCODE5_*_PP_PATH      = clang
+*_XCODE5_*_VFRPP_PATH   = clang
+*_XCODE5_*_ASL_PATH     = iasl
+*_XCODE5_*_ASLCC_PATH   = clang
+*_XCODE5_*_ASLPP_PATH   = clang
+*_XCODE5_*_ASLDLINK_PATH  = ld
+
+####################
+# IA-32 definitions
+####################
+  DEBUG_XCODE5_IA32_DLINK_FLAGS      = -arch i386 -u _$(IMAGE_ENTRY_POINT) -e _$(IMAGE_ENTRY_POINT) -preload -segalign 0x20  -pie -all_load -dead_strip -seg1addr 0x240 -read_only_relocs suppress -map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
+  NOOPT_XCODE5_IA32_DLINK_FLAGS      = -arch i386 -u _$(IMAGE_ENTRY_POINT) -e _$(IMAGE_ENTRY_POINT) -preload -segalign 0x20  -pie -all_load -dead_strip -seg1addr 0x240 -read_only_relocs suppress -map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
+RELEASE_XCODE5_IA32_DLINK_FLAGS      = -arch i386 -u _$(IMAGE_ENTRY_POINT) -e _$(IMAGE_ENTRY_POINT) -preload -segalign 0x20  -pie -all_load -dead_strip -seg1addr 0x240 -read_only_relocs suppress -map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
+
+*_XCODE5_IA32_SLINK_FLAGS      = -static -o
+  DEBUG_XCODE5_IA32_ASM_FLAGS  = -arch i386 -g
+  NOOPT_XCODE5_IA32_ASM_FLAGS  = -arch i386 -g
+RELEASE_XCODE5_IA32_ASM_FLAGS  = -arch i386 
+
+
+  DEBUG_XCODE5_IA32_CC_FLAGS   = -arch i386 -c -g -Os       -Wall -Werror -include AutoGen.h -funsigned-char -fno-stack-protector -fno-builtin -fshort-wchar -fasm-blocks -mdynamic-no-pic -mno-implicit-float -mms-bitfields -msoft-float -Wno-unused-parameter -Wno-missing-braces -Wno-missing-field-initializers -Wno-tautological-compare -Wno-sign-compare -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang $(PLATFORM_FLAGS)
+RELEASE_XCODE5_IA32_CC_FLAGS   = -arch i386 -c    -Os       -Wall -Werror -include AutoGen.h -funsigned-char -fno-stack-protector -fno-builtin -fshort-wchar -fasm-blocks -mdynamic-no-pic -mno-implicit-float -mms-bitfields -msoft-float -Wno-unused-parameter -Wno-missing-braces -Wno-missing-field-initializers -Wno-tautological-compare -Wno-sign-compare -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang $(PLATFORM_FLAGS)
+  NOOPT_XCODE5_IA32_CC_FLAGS   = -arch i386 -c -g -O0       -Wall -Werror -include AutoGen.h -funsigned-char -fno-stack-protector -fno-builtin -fshort-wchar -fasm-blocks -mdynamic-no-pic -mno-implicit-float -mms-bitfields -msoft-float -Wno-unused-parameter -Wno-missing-braces -Wno-missing-field-initializers -Wno-tautological-compare -Wno-sign-compare -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang $(PLATFORM_FLAGS)
+
+
+
+##################
+# X64 definitions
+##################
+  DEBUG_XCODE5_X64_DLINK_FLAGS      = -arch x86_64 -u _$(IMAGE_ENTRY_POINT) -e _$(IMAGE_ENTRY_POINT) -preload -segalign 0x20  -pie -all_load -dead_strip -seg1addr 0x240 -map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
+  NOOPT_XCODE5_X64_DLINK_FLAGS      = -arch x86_64 -u _$(IMAGE_ENTRY_POINT) -e _$(IMAGE_ENTRY_POINT) -preload -segalign 0x20  -pie -all_load -dead_strip -seg1addr 0x240 -map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
+RELEASE_XCODE5_X64_DLINK_FLAGS      = -arch x86_64 -u _$(IMAGE_ENTRY_POINT) -e _$(IMAGE_ENTRY_POINT) -preload -segalign 0x20  -pie -all_load -dead_strip -seg1addr 0x240 -map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
+
+*_XCODE5_X64_SLINK_FLAGS      = -static -o
+  DEBUG_XCODE5_X64_ASM_FLAGS  = -arch x86_64 -g
+  NOOPT_XCODE5_X64_ASM_FLAGS  = -arch x86_64 -g
+RELEASE_XCODE5_X64_ASM_FLAGS  = -arch x86_64 
+*_XCODE5_*_PP_FLAGS         = -E -x assembler-with-cpp -include $(DEST_DIR_DEBUG)/AutoGen.h 
+*_XCODE5_*_VFRPP_FLAGS      = -x c -E -P -DVFRCOMPILE -include $(DEST_DIR_DEBUG)/$(MODULE_NAME)StrDefs.h 
+
+
+  DEBUG_XCODE5_X64_CC_FLAGS   = -target x86_64-pc-win32-macho -c -g -Os       -Wall -Werror -Wextra -include AutoGen.h -funsigned-char -fno-ms-extensions -fno-stack-protector -fno-builtin -fshort-wchar -mno-implicit-float -mms-bitfields -Wno-unused-parameter -Wno-missing-braces -Wno-missing-field-initializers -Wno-tautological-compare -Wno-sign-compare -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang $(PLATFORM_FLAGS)
+  NOOPT_XCODE5_X64_CC_FLAGS   = -target x86_64-pc-win32-macho -c -g -O0       -Wall -Werror -Wextra -include AutoGen.h -funsigned-char -fno-ms-extensions -fno-stack-protector -fno-builtin -fshort-wchar -mno-implicit-float -mms-bitfields -Wno-unused-parameter -Wno-missing-braces -Wno-missing-field-initializers -Wno-tautological-compare -Wno-sign-compare -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang $(PLATFORM_FLAGS)
+RELEASE_XCODE5_X64_CC_FLAGS   = -target x86_64-pc-win32-macho -c    -Os       -Wall -Werror -Wextra -include AutoGen.h -funsigned-char -fno-ms-extensions -fno-stack-protector -fno-builtin -fshort-wchar -mno-implicit-float -mms-bitfields -Wno-unused-parameter -Wno-missing-braces -Wno-missing-field-initializers -Wno-tautological-compare -Wno-sign-compare -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang $(PLATFORM_FLAGS)
+
+*_XCODE5_*_ASLCC_FLAGS      = -x c -save-temps -g -O0 -fshort-wchar -fno-strict-aliasing -Wall -Werror -Wno-missing-braces -c -include AutoGen.h 
+*_XCODE5_*_ASLDLINK_FLAGS   = -e _ReferenceAcpiTable -preload -segalign 0x20  -pie -seg1addr 0x240 -read_only_relocs suppress -map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
+*_XCODE5_*_ASLPP_FLAGS      = -x c -E 
+*_XCODE5_*_ASL_FLAGS        =
+*_XCODE5_*_ASL_OUTFLAGS     = DEF(IASL_OUTFLAGS)
+
 ####################################################################################
 #
 # RVCT Common