Add crosscompile support to Makefile

tools/reader/Makefile

@@ -1,11 +1,32 @@
-CC = gcc
+ifneq "$(TUPLE)" ""
+PREFIX=$(TUPLE)-
+ARCH=$(shell echo $(TUPLE)|sed 's/-.*//')
+else
+PREFIX=
+ARCH=$(shell uname -m)
+endif
+
+CC = $(PREFIX)gcc
+STRIP = $(PREFIX)strip
+
 CFLAGS = -Wall -O2
 EXE = obreader
 FILES = obreader.c
-OBJS = obreader.o
 
-all: $(FILES)
-	$(CC) $(CFLAGS) $(FILES) -o $(EXE)
+$(ARCH)-$(EXE):
+	$(CC) $(CFLAGS) -o $@ $(FILES)
+	$(STRIP) $@
+
+
+# Using OpenWRT crossbuild environment, see
+# <URL:http://wiki.openwrt.org/doc/devel/crosscompile>
+# for setup instructions.
+WRT=~/r0ket/openwrt/trunk/staging_dir
+
+mips:
+	STAGING_DIR=$(WRT)/toolchain-mips_r2_gcc-4.6-linaro_uClibc-0.9.33.2 \
+	PATH=${PATH}:$(STAGING_DIR)/bin \
+	$(MAKE) TUPLE=mips-openwrt-linux
 
 clean: 
-	rm -f $(EXE) $(OBJS)
+	rm -f *-$(EXE)