diff --git a/make_helpers/build_macros.mk b/make_helpers/build_macros.mk
index fabd74e..9eb9d1e 100644
--- a/make_helpers/build_macros.mk
+++ b/make_helpers/build_macros.mk
@@ -17,22 +17,6 @@
 $(strip $(foreach d,$(wildcard ${1}*),$(call rwildcard,${d}/,${2}) $(filter $(subst *,%,%${2}),${d})))
 endef
 
-# This table is used in converting lower case to upper case.
-uppercase_table:=a,A b,B c,C d,D e,E f,F g,G h,H i,I j,J k,K l,L m,M n,N o,O p,P q,Q r,R s,S t,T u,U v,V w,W x,X y,Y z,Z
-
-# Internal macro used for converting lower case to upper case.
-#   $(1) = upper case table
-#   $(2) = String to convert
-define uppercase_internal
-$(if $(1),$$(subst $(firstword $(1)),$(call uppercase_internal,$(wordlist 2,$(words $(1)),$(1)),$(2))),$(2))
-endef
-
-# A macro for converting a string to upper case
-#   $(1) = String to convert
-define uppercase
-$(eval uppercase_result:=$(call uppercase_internal,$(uppercase_table),$(1)))$(uppercase_result)
-endef
-
 # Convenience function for setting a variable to 0 if not previously set
 # $(eval $(call default_zero,FOO))
 define default_zero
diff --git a/make_helpers/utilities.mk b/make_helpers/utilities.mk
index 62769fb..5bb1806 100644
--- a/make_helpers/utilities.mk
+++ b/make_helpers/utilities.mk
@@ -20,3 +20,31 @@
 directory-name = $(call decompat-path,$(dir $(call compat-path,$(1))))
 
 escape-shell = '$(subst ','\'',$(1))'
+
+#
+# Upper-case a string value.
+#
+# Parameters:
+#
+#   - $(1): The string to upper-case.
+#
+# Example usage:
+#
+#     $(call uppercase,HeLlO wOrLd) # "HELLO WORLD"
+#
+
+uppercase = $(shell echo $(call escape-shell,$(1)) | tr '[:lower:]' '[:upper:]')
+
+#
+# Lower-case a string value.
+#
+# Parameters:
+#
+#   - $(1): The string to lower-case.
+#
+# Example usage:
+#
+#     $(call lowercase,HeLlO wOrLd) # "hello world"
+#
+
+lowercase = $(shell echo $(call escape-shell,$(1)) | tr '[:upper:]' '[:lower:]')
diff --git a/plat/mediatek/build_helpers/mtk_build_helpers.mk b/plat/mediatek/build_helpers/mtk_build_helpers.mk
index ac2cbad..87a7db4 100644
--- a/plat/mediatek/build_helpers/mtk_build_helpers.mk
+++ b/plat/mediatek/build_helpers/mtk_build_helpers.mk
@@ -27,12 +27,10 @@
 # Determine option variable is defined or not then define it
 define add_defined_option
 ifdef $(1)
-ifeq ($(findstring $(value $(1)), $(uppercase_table)),)
-DEFINES += -D$(1)$(if $(value $(1)),=$(value $(1)),)
-else
 ifeq ($(strip $(value $(1))),y)
 DEFINES += -D$(1)$(if $(value $(1)),=1,)
-endif
+else
+DEFINES += -D$(1)$(if $(value $(1)),=$(value $(1)),)
 endif
 endif
 endef