diff --git a/Tuprules.tup b/Tuprules.tup
index 02052584f..9d0096053 100644
--- a/Tuprules.tup
+++ b/Tuprules.tup
@@ -70,12 +70,10 @@ export LD
 CC = $CC
 CXX = $CXX
 LD= $LD
-AR = $(TOOL_CHAIN_PREFIX)ar
-AS = $(TOOL_CHAIN_PREFIX)as
-OBJCOPY = $(TOOL_CHAIN_PREFIX)objcopy
-AS_OPT += $(AS_MARCH)
+OBJCOPY = $OBJCOPY
 
-CXXFLAGS += -Wno-undefined-bool-conversion -Wno-unknown-attributes -Wno-unused-command-line-argument
+CXXFLAGS += -Wno-undefined-bool-conversion -Wno-unknown-attributes -Wsystem-headers -Werror
+#CXXFLAGS +=  -Wno-unused-command-line-argument
 
 export NIX_PATH
 NIX_BUILD = nix-build --option substitute no
@@ -86,15 +84,16 @@ LIB_DIR = $(OUTPUTS_DEV)/lib
 PKG_CONFIG_DIR = $(OUTPUTS_DEV)/lib/pkgconfig
 PKG_CONFIG = PKG_CONFIG_PATH=$(PKG_CONFIG_DIR) pkg-config
 
-!asm = |> ^ CC %b^ @(CC_WRAPPER) $(CC) $(DEFINES) $(CFLAGS) $(CFLAGS_%e) $(CFLAGS_%f) -D__ASSEMBLY__ $(INCLUDES) -c %f -o %o |> %B.o
+DEFINES += -g
+OLEVEL = -O0
 
-!cc = | $(GENODE_DIR)/<pkg-config> |> ^o CC %f^ @(CC_WRAPPER) $(CC) $(DEFINES) $(CFLAGS) $(CFLAGS_%e) $(CFLAGS_%f) `$(PKG_CONFIG) --cflags $(LIBS) $(LIBS_CFLAGS)` $(INCLUDES) -c -fPIC -g %f -o %o |> %B.o
+!ir = | $(GENODE_DIR)/<pkg-config> |> clang $(OLEVEL) $(DEFINES) $(CXXFLAGS) $(CXXFLAGS_%e) $(CXXFLAGS_%f) `$(PKG_CONFIG) --cflags $(LIBS)` $(INCLUDES) -S -emit-llvm %f |> %B.ll
 
-!cc_port = | $(GENODE_DIR)/<pkg-config> |> ^o CC %o^ @(CC_WRAPPER) $(CC) $(DEFINES) $(CFLAGS) $(CFLAGS_%o) $(INCLUDES) `$(PKG_CONFIG) --cflags $(LIBS) $(LIBS_CFLAGS)` -c -fPIC -g -o %o |> %B.o
+!asm = |> ^ CC %b^ @(CC_WRAPPER) $(CC) $(OLEVEL) $(DEFINES) $(CFLAGS) $(CFLAGS_%e) $(CFLAGS_%f) -D__ASSEMBLY__ $(INCLUDES) -c %f -o %o |> %B.o
 
-!cxx = | $(GENODE_DIR)/<pkg-config> |> ^o CXX %b^ @(CC_WRAPPER) $(CXX) $(DEFINES) $(CXXFLAGS) $(CXXFLAGS_%e) $(CXXFLAGS_%f) `$(PKG_CONFIG) --cflags $(LIBS)` $(INCLUDES) -c -fPIC -g %f -o %o |> %B.o
+!cc = | $(GENODE_DIR)/<pkg-config> |> ^o CC %f^ @(CC_WRAPPER) $(CC) $(OLEVEL) $(DEFINES) $(CFLAGS) $(CFLAGS_%e) $(CFLAGS_%f) `$(PKG_CONFIG) --cflags $(LIBS) $(LIBS_CFLAGS)` $(INCLUDES) -c -fPIC %f -o %o |> %B.o
 
-!cxx_port = | $(GENODE_DIR)/<pkg-config> |> ^o CXX %o^ @(CC_WRAPPER) $(CXX) $(DEFINES) $(CXXFLAGS) $(CXXFLAGS_%f) `$(PKG_CONFIG) --cflags $(LIBS)` $(INCLUDES) -c -fPIC -g -o %o |> %B.o
+!cxx = | $(GENODE_DIR)/<pkg-config> |> ^o CXX %b^ @(CC_WRAPPER) $(CXX) $(OLEVEL) $(DEFINES) $(CXXFLAGS) $(CXXFLAGS_%e) $(CXXFLAGS_%f) `$(PKG_CONFIG) --cflags $(LIBS)` $(INCLUDES) -c -fPIC %f -o %o |> %B.o
 
 !ld = | $(GENODE_DIR)/<lib> $(GENODE_DIR)/<pkg-config> |> ^o LD %o^ $(LD) $(LDFLAGS) `$(PKG_CONFIG) --libs $(LIBS)` --whole-archive --start-group %f --no-whole-archive --end-group -o %o |>
 
@@ -138,11 +137,11 @@ endif
 BASE_DIR = $(GENODE_DIR)/repos/base
 &BASE_DIR = repos/base
 
-export AS
 !incbin = |> ^ incbin %f^ \
 	export SYM=_binary_`echo %f | sed 's/\./_/g'`; \
-	echo ".global ${SYM}_start, ${SYM}_end; .data; .align 4; ${SYM}_start:; .incbin \"%f\"; ${SYM}_end:" |\
-		$AS $(AS_MARCH) -f -o %o - |> binary_%b.o
+	echo ".global ${SYM}_start, ${SYM}_end; .data; .align 4; ${SYM}_start:; .incbin \"%f\"; ${SYM}_end:" \
+		| llvm-mc -filetype=obj - > %o \
+|> binary_%b.o
 
 export AR
 !ar = |> ^ MERGE %o^ $AR -rcs %o %f |>
diff --git a/repos/base-linux/src/lib/syscall/Tupfile b/repos/base-linux/src/lib/syscall/Tupfile
index a5f4c9df8..1c1cdd30e 100644
--- a/repos/base-linux/src/lib/syscall/Tupfile
+++ b/repos/base-linux/src/lib/syscall/Tupfile
@@ -18,5 +18,5 @@ ifeq ($(SPEC_DIR),)
 	error syscall library is missing rules for @(TUP_ARCH)
 endif
 
-: foreach $(SPEC_DIR)/*.S |> !cc |> {obj}
+: foreach $(SPEC_DIR)/*.S |> !asm |> {obj}
 : {obj} |> !ar |> syscall-linux.lib.a
diff --git a/repos/base/Tuprules.tup b/repos/base/Tuprules.tup
index 43235d63a..59780bbec 100644
--- a/repos/base/Tuprules.tup
+++ b/repos/base/Tuprules.tup
@@ -21,8 +21,6 @@ INCLUDES += -I$(BASE_DIR)/include
 
 # Override base macros to bypass pkg-config
 
-CC_OLEVEL = -O2
-
 DEFINES += \
 	-ffunction-sections \
 	-fno-strict-aliasing \
@@ -37,14 +35,14 @@ CXXFLAGS += \
 GCC_INCLUDE = -I`$(CC) -print-file-name=include`
 
 !cc = |> ^ COMPILE %b^ \
-	@(CC_WRAPPER) $(CC) $(DEFINES) $(CC_OLEVEL) \
+	@(CC_WRAPPER) $(CC) $(DEFINES) $(OLEVEL) \
 	$(CFLAGS) $(CFLAGS_%e) $(CFLAGS_%f) \
 	$(INCLUDES) $(GCC_INCLUDE) $(CC_MARCH) \
 	-c %f -o %o \
 |> %B.o
 
 !cxx = |> ^ COMPILE %b^ \
-	@(CC_WRAPPER) $(CXX) $(DEFINES) $(CC_OLEVEL) \
+	@(CC_WRAPPER) $(CXX) $(DEFINES) $(OLEVEL) \
 	$(CXXFLAGS) $(CXXFLAGS_%e) $(CXXFLAGS_%f) \
 	$(INCLUDES) $(GCC_INCLUDE) $(CC_MARCH) \
 	-c %f -o %o \