+# SHELL used by kbuild
+CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
+ else if [ -x /bin/bash ]; then echo /bin/bash; \
+ else echo sh; fi ; fi)
+
+HOSTCC = gcc
+HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
+
+ifeq ($(HOSTOS),cygwin)
+HOSTCFLAGS += -ansi
+endif
+
+# Mac OS X / Darwin's C preprocessor is Apple specific. It
+# generates numerous errors and warnings. We want to bypass it
+# and use GNU C's cpp. To do this we pass the -traditional-cpp
+# option to the compiler. Note that the -traditional-cpp flag
+# DOES NOT have the same semantics as GNU C's flag, all it does
+# is invoke the GNU preprocessor in stock ANSI/ISO C fashion.
+#
+# Apple's linker is similar, thanks to the new 2 stage linking
+# multiple symbol definitions are treated as errors, hence the
+# -multiply_defined suppress option to turn off this error.
+#
+ifeq ($(HOSTOS),darwin)
+# get major and minor product version (e.g. '10' and '6' for Snow Leopard)
+DARWIN_MAJOR_VERSION = $(shell sw_vers -productVersion | cut -f 1 -d '.')
+DARWIN_MINOR_VERSION = $(shell sw_vers -productVersion | cut -f 2 -d '.')
+
+os_x_before = $(shell if [ $(DARWIN_MAJOR_VERSION) -le $(1) -a \
+ $(DARWIN_MINOR_VERSION) -le $(2) ] ; then echo "$(3)"; else echo "$(4)"; fi ;)
+
+# Snow Leopards build environment has no longer restrictions as described above
+HOSTCC = $(call os_x_before, 10, 5, "cc", "gcc")
+HOSTCFLAGS += $(call os_x_before, 10, 4, "-traditional-cpp")
+HOSTLDFLAGS += $(call os_x_before, 10, 5, "-multiply_defined suppress")
+endif
+
+# Make variables (CC, etc...)
+
+AS = $(CROSS_COMPILE)as
+# Always use GNU ld
+ifneq ($(shell $(CROSS_COMPILE)ld.bfd -v 2> /dev/null),)
+LD = $(CROSS_COMPILE)ld.bfd
+else
+LD = $(CROSS_COMPILE)ld
+endif
+CC = $(CROSS_COMPILE)gcc
+CPP = $(CC) -E
+AR = $(CROSS_COMPILE)ar
+NM = $(CROSS_COMPILE)nm
+LDR = $(CROSS_COMPILE)ldr
+STRIP = $(CROSS_COMPILE)strip
+OBJCOPY = $(CROSS_COMPILE)objcopy
+OBJDUMP = $(CROSS_COMPILE)objdump
+AWK = awk
+RANLIB = $(CROSS_COMPILE)RANLIB
+DTC = dtc
+CHECK = sparse
+
+CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
+ -Wbitwise -Wno-return-void -D__CHECK_ENDIAN__ $(CF)
+
+export CONFIG_SHELL HOSTCC HOSTCFLAGS HOSTLDFLAGS CROSS_COMPILE AS LD CC
+export CPP AR NM LDR STRIP OBJCOPY OBJDUMP
+export MAKE AWK
+export DTC CHECK CHECKFLAGS
+