+# Do not print "Entering directory ...",
+# but we want to display it when entering to the output directory
+# so that IDEs/editors are able to understand relative filenames.
+MAKEFLAGS += --no-print-directory
+
+# Call a source code checker (by default, "sparse") as part of the
+# C compilation.
+#
+# Use 'make C=1' to enable checking of only re-compiled files.
+# Use 'make C=2' to enable checking of *all* source files, regardless
+# of whether they are re-compiled or not.
+#
+# See the file "Documentation/sparse.txt" for more details, including
+# where to get the "sparse" utility.
+
+ifeq ("$(origin C)", "command line")
+ KBUILD_CHECKSRC = $(C)
+endif
+ifndef KBUILD_CHECKSRC
+ KBUILD_CHECKSRC = 0
+endif
+
+# Use make M=dir to specify directory of external module to build
+# Old syntax make ... SUBDIRS=$PWD is still supported
+# Setting the environment variable KBUILD_EXTMOD take precedence
+ifdef SUBDIRS
+ KBUILD_EXTMOD ?= $(SUBDIRS)
+endif
+
+ifeq ("$(origin M)", "command line")
+ KBUILD_EXTMOD := $(M)
+endif
+