[PATCH] Makefile:add cross_compiler for Makefile

[Yuanbin Zhou <hduffddybz@gmail.com>]

In this site(https://rt.wiki.kernel.org/index.php/Cyclictest), It has been shown that you can use "make CROSS_COPILE=<your-compiler-prefix>" to build software ran in other platform like arm & mips, but in fact it does not work, this patch is used to solve this problem.

Signed-off-by: Yuanbin Zhou <hduffddybz@gmail.com>
---
 Makefile | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Makefile b/Makefile
index a48e759..9b31ce4 100644
--- a/Makefile
+++ b/Makefile
@@ -11,6 +11,17 @@ sources += signaltest.c ptsematest.c sigwaittest.c svsematest.c sendme.c \
 
 TARGETS = $(sources:.c=)
 
+CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)
+AS = $(CROSS_COMPILE)as
+LD = $(CROSS_COMPILE)ld
+CC = $(CROSS_COMPILE)gcc
+CPP = $(CC) -E
+AR = $(CROSS_COMPILE)ar
+NM = $(CROSS_COMPILE)nm
+STRIP = $(CROSS_COMPILE)strip
+OBJCOPY = $(CROSS_COMPILE)objcopy
+OBJDUMP = $(CROSS_COMPILE)objdump
+
 LIBS	= -lrt -lpthread
 RTTESTLIB = -lrttest -L.
 EXTRA_LIBS ?= -ldl	# for get_cpu
-- 
2.1.4