tests: TFI build fixes
diff --git a/tests/TFI/README b/tests/TFI/README
index 6fc1479..74188cc 100644
--- a/tests/TFI/README
+++ b/tests/TFI/README
@@ -1,6 +1,6 @@
 * Note
 
-  - This directory contains "tests for MARS internal functions".
+  - This directory contains "functional tests for MARS internal functions".
 
     o These internal tests require MARS source code and you need to
       specify MARS_SRC= option to build and/or run them. See README in
@@ -8,7 +8,8 @@
 
     o Use 'config_internal.mk' instead of 'config.mk' in Makefile.
 
-    o This directory isn't visited by top level Makefile.
+    o This directory isn't visited by top level Makefile unless MARS_SRC is
+      specified.
 
 ---
 EOF
diff --git a/tests/TFI/TFI_14_002/Makefile b/tests/TFI/TFI_14_002/Makefile
index ad471cc..0238fcd 100644
--- a/tests/TFI/TFI_14_002/Makefile
+++ b/tests/TFI/TFI_14_002/Makefile
@@ -27,4 +27,4 @@
 include $(top_srcdir)/scripts/config_internal.mk
 include $(top_srcdir)/scripts/rules_item.mk
 
-mpu.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.o
+mpu.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.mpu_o
diff --git a/tests/TFI/TFI_14_003/Makefile b/tests/TFI/TFI_14_003/Makefile
index ad471cc..0238fcd 100644
--- a/tests/TFI/TFI_14_003/Makefile
+++ b/tests/TFI/TFI_14_003/Makefile
@@ -27,4 +27,4 @@
 include $(top_srcdir)/scripts/config_internal.mk
 include $(top_srcdir)/scripts/rules_item.mk
 
-mpu.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.o
+mpu.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.mpu_o
diff --git a/tests/TFI/TFI_15_002/Makefile b/tests/TFI/TFI_15_002/Makefile
index 9434183..0b9627a 100644
--- a/tests/TFI/TFI_15_002/Makefile
+++ b/tests/TFI/TFI_15_002/Makefile
@@ -27,7 +27,7 @@
 include $(top_srcdir)/scripts/config_internal.mk
 include $(top_srcdir)/scripts/rules_item.mk
 
-mpu1.mpu mpu2.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.o
+mpu1.mpu mpu2.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.mpu_o
 
 host.o: host_and_mpu.h
 mpu1.mpu_o: host_and_mpu.h
diff --git a/tests/TFI/TFI_15_003/Makefile b/tests/TFI/TFI_15_003/Makefile
index ad471cc..0238fcd 100644
--- a/tests/TFI/TFI_15_003/Makefile
+++ b/tests/TFI/TFI_15_003/Makefile
@@ -27,4 +27,4 @@
 include $(top_srcdir)/scripts/config_internal.mk
 include $(top_srcdir)/scripts/rules_item.mk
 
-mpu.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.o
+mpu.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.mpu_o
diff --git a/tests/TFI/TFI_15_004/Makefile b/tests/TFI/TFI_15_004/Makefile
index ad471cc..0238fcd 100644
--- a/tests/TFI/TFI_15_004/Makefile
+++ b/tests/TFI/TFI_15_004/Makefile
@@ -27,4 +27,4 @@
 include $(top_srcdir)/scripts/config_internal.mk
 include $(top_srcdir)/scripts/rules_item.mk
 
-mpu.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.o
+mpu.mpu: $(MARS_BUILD)/base/src/mpu/kernel/mutex.mpu_o