diff --git a/graphics/Makefile b/graphics/Makefile
index 2e4d9d1fae..b000d11fbe 100644
--- a/graphics/Makefile
+++ b/graphics/Makefile
@@ -138,6 +138,11 @@ mklibgraphics: $(BIN)
 
 depend: .depend
 
+clean_context:
+	$(Q) $(MAKE) -C nxglib -f Makefile.devblit distclean TOPDIR=$(TOPDIR) EXTRADEFINES=$(EXTRADEFINES)
+	$(Q) $(MAKE) -C nxglib -f Makefile.pwfb distclean TOPDIR=$(TOPDIR) EXTRADEFINES=$(EXTRADEFINES)
+	$(Q) $(MAKE) -C nxglib -f Makefile.cursor distclean TOPDIR=$(TOPDIR) EXTRADEFINES=$(EXTRADEFINES)
+
 context: gensources
 
 clean:
@@ -147,10 +152,7 @@ clean:
 	$(call DELFILE, $(BIN))
 	$(call CLEAN)
 
-distclean: clean
-	$(Q) $(MAKE) -C nxglib -f Makefile.devblit distclean TOPDIR=$(TOPDIR) EXTRADEFINES=$(EXTRADEFINES)
-	$(Q) $(MAKE) -C nxglib -f Makefile.pwfb distclean TOPDIR=$(TOPDIR) EXTRADEFINES=$(EXTRADEFINES)
-	$(Q) $(MAKE) -C nxglib -f Makefile.cursor distclean TOPDIR=$(TOPDIR) EXTRADEFINES=$(EXTRADEFINES)
+distclean: clean clean_context
 	$(call DELFILE, Make.dep)
 	$(call DELFILE, .depend)
 
diff --git a/tools/Directories.mk b/tools/Directories.mk
index ab12a3f561..61fd385a50 100644
--- a/tools/Directories.mk
+++ b/tools/Directories.mk
@@ -39,8 +39,11 @@
 # CONTEXTDIRS include directories that have special, one-time pre-build
 #   requirements.  Normally this includes things like auto-generation of
 #   configuration specific files or creation of configurable symbolic links
-# CLEANDIRS are the directories that will clean in.  These are
-#   all directories that we know about.
+# CLEANDIRS are the directories that the clean target will executed in.
+#   These are all directories that we know about.
+# CCLEANDIRS are directories that the clean_context target will execute in.
+#   The clean_context target "undoes" the actions of the context target.
+#   Only directories known to require cleaning are included.
 # KERNDEPDIRS are the directories in which we will build target dependencies.
 #   If NuttX and applications are built separately (CONFIG_BUILD_PROTECTED or
 #   CONFIG_BUILD_KERNEL), then this holds only the directories containing
@@ -50,6 +53,7 @@
 #   CONFIG_BUILD_KERNEL is selected, then applications are not build at all.
 
 CLEANDIRS :=
+CCLEANDIRS := boards $(APPDIR) graphics
 KERNDEPDIRS :=
 USERDEPDIRS :=
 
diff --git a/tools/Makefile.unix b/tools/Makefile.unix
index 7107578894..39d016c45d 100644
--- a/tools/Makefile.unix
+++ b/tools/Makefile.unix
@@ -109,8 +109,11 @@ APPDIR := ${shell if [ -r $(CONFIG_APPS_DIR)/Makefile ]; then echo "$(CONFIG_APP
 # CONTEXTDIRS include directories that have special, one-time pre-build
 #   requirements.  Normally this includes things like auto-generation of
 #   configuration specific files or creation of configurable symbolic links
-# CLEANDIRS are the directories that will clean in.  These are
-#   all directories that we know about.
+# CLEANDIRS are the directories that the clean target will executed in.
+#   These are all directories that we know about.
+# CCLEANDIRS are directories that the clean_context target will execute in.
+#   The clean_context target "undoes" the actions of the context target.
+#   Only directories known to require cleaning are included.
 # KERNDEPDIRS are the directories in which we will build target dependencies.
 #   If NuttX and applications are built separately (CONFIG_BUILD_PROTECTED or
 #   CONFIG_BUILD_KERNEL), then this holds only the directories containing
@@ -393,8 +396,11 @@ context: check_context staging include/nuttx/config.h include/nuttx/version.h in
 # and symbolic links created by the context target.
 
 clean_context:
-	$(Q) $(MAKE) -C boards TOPDIR="$(TOPDIR)" clean_context
-	$(Q) $(MAKE) -C $(CONFIG_APPS_DIR) TOPDIR="$(TOPDIR)" clean_context
+	$(Q) for dir in $(CCLEANDIRS) ; do \
+		if [ -e $$dir/Makefile ]; then \
+			$(MAKE) -C $$dir TOPDIR="$(TOPDIR)" clean_context ; \
+		fi \
+	done
 	$(call DELFILE, include/math.h)
 	$(call DELFILE, include/stdarg.h)
 	$(call DELFILE, include/setjmp.h)
diff --git a/tools/Makefile.win b/tools/Makefile.win
index a40ab7cb20..aa66a338a9 100644
--- a/tools/Makefile.win
+++ b/tools/Makefile.win
@@ -91,8 +91,11 @@ APPDIR := ${shell if exist "$(CONFIG_APPS_DIR)\Makefile" echo $(CONFIG_APPS_DIR)
 # CONTEXTDIRS include directories that have special, one-time pre-build
 #   requirements.  Normally this includes things like auto-generation of
 #   configuration specific files or creation of configurable symbolic links
-# CLEANDIRS are the directories that will clean in.  These are
-#   all directories that we know about.
+# CLEANDIRS are the directories that the clean target will executed in.
+#   These are all directories that we know about.
+# CCLEANDIRS are directories that the clean_context target will execute in.
+#   The clean_context target "undoes" the actions of the context target.
+#   Only directories known to require cleaning are included.
 # KERNDEPDIRS are the directories in which we will build target dependencies.
 #   If NuttX and applications are built separately (CONFIG_BUILD_PROTECTED or
 #   CONFIG_BUILD_KERNEL), then this holds only the directories containing
@@ -407,8 +410,7 @@ context: check_context staging include\nuttx\config.h include\nuttx\version.h in
 # and symbolic links created by the context target.
 
 clean_context:
-	$(Q) $(MAKE) -C boards TOPDIR="$(TOPDIR)" clean_context
-	$(Q) $(MAKE) -C $(CONFIG_APPS_DIR) TOPDIR="$(TOPDIR)" clean_context
+	$(Q) for %%G in ($(CCLEANDIRS)) do ( if exist %%G\Makefile $(MAKE) -C %%G TOPDIR="$(TOPDIR)" clean_context )
 	$(call DELFILE, include\nuttx\config.h)
 	$(call DELFILE, include\nuttx\version.h)
 	$(call DELFILE, include\math.h)
diff --git a/tools/nxstyle.c b/tools/nxstyle.c
index 4031f33007..165c5becc1 100644
--- a/tools/nxstyle.c
+++ b/tools/nxstyle.c
@@ -285,6 +285,13 @@ int main(int argc, char **argv, char **envp)
                * REVISIT: Generates a false alarm if the current line is also
                * a comment.  Generally it is acceptable for one comment to
                * follow another with no space separation.
+               *
+               * REVISIT: prevbrhcmt is tested to case the preceding line
+               * contained comments to the right of the code.  In such cases,
+               * the comments are normally aligned and do not follow normal
+               * indentation rules.  However, this code will generate a false
+               * alarm if the comments are aligned to the right BUT the
+               * preceding line has no comment.
                */
 
               if (line[n] != '}' /* && line[n] != '#' */ && !prevbrhcmt)