diff --git a/os/common/startup/ARMCMx/compilers/LLVM/mk/clang.mk b/os/common/startup/ARMCMx/compilers/LLVM/mk/clang.mk
index db0f1e4a8..812f277d2 100644
--- a/os/common/startup/ARMCMx/compilers/LLVM/mk/clang.mk
+++ b/os/common/startup/ARMCMx/compilers/LLVM/mk/clang.mk
@@ -1,19 +1,20 @@
-##############################################################################
-# Compiler settings
-#
-
-TRGT = aarch32-
-CC   = clang
-CPPC = clang++
-LD   = clang
-CP   = $(TRGT)objcopy
-AS   = $(TRGT)as -x assembler-with-cpp
-AR   = $(TRGT)ar
-OD   = $(TRGT)objdump
-SZ   = $(TRGT)size
-HEX  = $(CP) -O ihex
-BIN  = $(CP) -O binary
-
-#
-# Compiler settings
-##############################################################################
+##############################################################################
+# Compiler settings
+#
+
+TRGT   = llvm-
+CC     = clang
+GCC_CC = arm-none-eabi-gcc
+CPPC   = clang++
+LD     = $(GCC_CC)
+CP     = $(TRGT)objcopy
+AS     = $(TRGT)as -x assembler-with-cpp
+AR     = $(TRGT)ar
+OD     = $(TRGT)objdump
+SZ     = $(TRGT)size
+HEX    = $(CP) -O ihex
+BIN    = $(CP) -O binary
+
+#
+# Compiler settings
+##############################################################################
diff --git a/os/common/startup/ARMCMx/compilers/LLVM/mk/rules.mk b/os/common/startup/ARMCMx/compilers/LLVM/mk/rules.mk
index 0d6af76e4..b448f8d07 100644
--- a/os/common/startup/ARMCMx/compilers/LLVM/mk/rules.mk
+++ b/os/common/startup/ARMCMx/compilers/LLVM/mk/rules.mk
@@ -98,14 +98,13 @@ LSTDIR    := $(BUILDDIR)/lst
 
 # Object files groups
 TCOBJS    := $(addprefix $(OBJDIR)/, $(notdir $(TCSRC:.c=.o)))
-TCPPOBJS  := $(addprefix $(OBJDIR)/, $(notdir $(TCPPSRC:.cpp=.o)))
+#TCPPOBJS  := $(addprefix $(OBJDIR)/, $(notdir $(TCPPSRC:.cpp=.o)))
+TCPPOBJS  := $(addprefix $(OBJDIR)/, $(notdir $(patsubst %.cpp, %.o, $(filter %.cpp, $(TCPPSRC)))))
+TCCOBJS   := $(addprefix $(OBJDIR)/, $(notdir $(patsubst %.cc, %.o, $(filter %.cc, $(TCPPSRC)))))
 ASMOBJS   := $(addprefix $(OBJDIR)/, $(notdir $(ASMSRC:.s=.o)))
 ASMXOBJS  := $(addprefix $(OBJDIR)/, $(notdir $(ASMXSRC:.S=.o)))
-OBJS      := $(ASMXOBJS) $(ASMOBJS) $(ACOBJS) $(TCOBJS) $(ACPPOBJS) $(TCPPOBJS)
-
-# Paths
-IINCDIR   := $(patsubst %,-I%,$(INCDIR) $(DINCDIR) $(UINCDIR))
-LLIBDIR   := $(patsubst %,-L%,$(DLIBDIR) $(ULIBDIR))
+#OBJS      := $(ASMXOBJS) $(ASMOBJS) $(ACOBJS) $(TCOBJS) $(ACPPOBJS) $(TCPPOBJS)
+OBJS      := $(ASMXOBJS) $(ASMOBJS) $(ACOBJS) $(TCOBJS) $(ACPPOBJS) $(TCPPOBJS) $(TCCOBJS)
 
 # Macros
 DEFS      := $(DDEFS) $(UDEFS)
@@ -121,11 +120,18 @@ ASFLAGS   = $(MCFLAGS) $(OPT) $(ADEFS)
 ASXFLAGS  = $(MCFLAGS) $(OPT) $(ADEFS)
 CFLAGS    = $(MCFLAGS) $(OPT) $(COPT) $(CWARN) $(DEFS)
 CPPFLAGS  = $(MCFLAGS) $(OPT) $(CPPOPT) $(CPPWARN) $(DEFS)
-#ASFLAGS   = $(MCFLAGS) $(OPT) -Wa,-amhls=$(LSTDIR)/$(notdir $(<:.s=.lst)) $(ADEFS)
-#ASXFLAGS  = $(MCFLAGS) $(OPT) -Wa,-amhls=$(LSTDIR)/$(notdir $(<:.S=.lst)) $(ADEFS)
-#CFLAGS    = $(MCFLAGS) $(OPT) $(COPT) $(CWARN) -Wa,-alms=$(LSTDIR)/$(notdir $(<:.c=.lst)) $(DEFS)
-#CPPFLAGS  = $(MCFLAGS) $(OPT) $(CPPOPT) $(CPPWARN) -Wa,-alms=$(LSTDIR)/$(notdir $(<:.cpp=.lst)) $(DEFS)
-LDFLAGS   = $(MCFLAGS) $(OPT) -nostartfiles $(LLIBDIR) -Wl,-Map=$(BUILDDIR)/$(PROJECT).map,--cref,--no-warn-mismatch,--library-path=$(STARTUPLD),--script=$(LDSCRIPT)$(LDOPT)
+
+ARM_CORTEXM_SYSROOT := \
+	$(shell $(GCC_CC) $(CFLAGS) -print-sysroot 2>&1)
+ARM_CORTEXM_MULTI_DIR := \
+	$(shell $(GCC_CC) $(CFLAGS) -print-multi-directory 2>&1)
+ARM_CORTEXM_BUILTINS := \
+	$(shell $(GCC_CC) $(CFLAGS) -print-libgcc-file-name 2>&1)
+
+ASFLAGS   += --target=arm-none-eabi --sysroot=$(ARM_CORTEXM_SYSROOT)
+ASXFLAGS  += --target=arm-none-eabi --sysroot=$(ARM_CORTEXM_SYSROOT)
+CFLAGS    += --target=arm-none-eabi --sysroot=$(ARM_CORTEXM_SYSROOT)
+CPPFLAGS  += --target=arm-none-eabi --sysroot=$(ARM_CORTEXM_SYSROOT)
 
 # Generate dependency information
 ASFLAGS  += -MD -MP -MF $(DEPDIR)/$(@F).d
@@ -133,6 +139,11 @@ ASXFLAGS += -MD -MP -MF $(DEPDIR)/$(@F).d
 CFLAGS   += -MD -MP -MF $(DEPDIR)/$(@F).d
 CPPFLAGS += -MD -MP -MF $(DEPDIR)/$(@F).d
 
+# Paths
+IINCDIR   := $(patsubst %,-I%,$(INCDIR) $(DINCDIR) $(UINCDIR))
+LLIBDIR   := $(patsubst %,-L%,$(DLIBDIR) $(ULIBDIR) $(ARM_CORTEXM_SYSROOT)/lib/$(ARM_CORTEXM_MULTI_DIR))
+LDFLAGS   = $(MCFLAGS) $(OPT) -nostartfiles $(LLIBDIR) $(ARM_CORTEXM_BUILTINS) -Wl,-Map=$(BUILDDIR)/$(PROJECT).map,--cref,--no-warn-mismatch,--library-path=$(STARTUPLD),--script=$(LDSCRIPT)$(LDOPT)
+
 # Paths where to search for sources
 VPATH     = $(SRCPATHS)
 
@@ -174,6 +185,15 @@ else
 	@$(CPPC) -c $(CPPFLAGS) -I. $(IINCDIR) $< -o $@
 endif
 
+$(TCCOBJS) : $(OBJDIR)/%.o : %.cc $(MAKEFILE_LIST)
+ifeq ($(USE_VERBOSE_COMPILE),yes)
+	@echo
+	$(CPPC) -c $(CPPFLAGS) -I. $(IINCDIR) $< -o $@
+else
+	@echo Compiling $(<F)
+	@$(CPPC) -c $(CPPFLAGS) -I. $(IINCDIR) $< -o $@
+endif
+
 $(TCOBJS) : $(OBJDIR)/%.o : %.c $(MAKEFILE_LIST)
 ifeq ($(USE_VERBOSE_COMPILE),yes)
 	@echo
diff --git a/readme.txt b/readme.txt
index 3dbc2f68a..091585d93 100644
--- a/readme.txt
+++ b/readme.txt
@@ -74,6 +74,7 @@
 *****************************************************************************
 
 *** Next ***
+- NEW: Non-proprietary LLVM build support.
 - NEW: Added palReadGroupLatch() to PAL driver.
 - NEW: Added a Posix-favored shell named "msh" (Mini Shell). The shell is able
        to run sub-apps inside the same sandbox. The shell can either be placed