Some additional changes to compile properly

mrbgems/Makefile

 # makefile description.
 # add gems to the ruby library
 
-LIBRGEMS := ../lib/libmruby_gems.a
+LIBR := ../lib/libmruby.a
 INIT := init_gems
 RM_F := rm -f
 CC_FLAGS := -Wall -Werror-implicit-function-declaration -g -O3 -MMD -I. -I./../include
@@ -9,6 +9,7 @@ MMAKER := ./gem_helper
 MMAKER_BIN := $(MMAKER)
 export CC = gcc
 export LL = gcc
+export AR = ar
 
 ##############################
 # generic build targets, rules
@@ -16,17 +17,10 @@ export LL = gcc
 .PHONY : all
 all : $(INIT).o all_gems
 
-$(INIT).o : $(INIT).c
-	@echo "Build the driver which initiailizes all gems"
-	gcc $(CC_FLAGS) -c $< -o $@
-
-all_gems : $(MMAKER_BIN) g/Makefile
-	@echo "Build all gems"
-	$(MAKE) -C g
-
 $(MMAKER_BIN) : $(MMAKER).o
 	@echo "Build the generator which creates the driver and Gem Makefile"
 	$(LL) -o $@ $(CC_FLAGS) $<
+
 $(MMAKER).o : $(MMAKER).c
 	$(CC) $(CC_FLAGS) -MMD -c $< -o $@
 
@@ -34,10 +28,19 @@ $(INIT).c : $(MMAKER_BIN)
 	@echo "Generate Gem driver"
 	$(MMAKER_BIN) $(INIT) > $@
 
+$(INIT).o : $(INIT).c
+	@echo "Build the driver which initiailizes all gems"
+	gcc $(CC_FLAGS) -c $< -o $@
+	$(AR) rs $(LIBR) $@
+
 g/Makefile :
 	@echo "Generate Gem Makefile"
 	$(MMAKER_BIN) makefile > $@
 
+all_gems : $(MMAKER_BIN) g/Makefile
+	@echo "Build all gems"
+	$(MAKE) -C g
+
 # clean driver and all gems
 .PHONY : clean
 clean : $(MMAKER_BIN)

mrbgems/g/md5/Makefile

@@ -7,13 +7,14 @@ RM_F := rm -f
 AR := ar
 
 ifeq ($(strip $(LIBR)),)
-  # default compile option
+  # default mruby library
   LIBR = $(MRUBY_ROOT)lib/libmruby.a
 endif
 
+.PHONY : all
 all : src/md5.o src/mrb_md5.o
-	@echo "Gem '$(GEMNAME)' is done"
 	@$(AR) rs $(LIBR) src/md5.o src/mrb_md5.o
+	@echo "Gem '$(GEMNAME)' is done"
 
 md5.o : src/md5.c
 	@gcc -c -I. src/md5.c
@@ -21,5 +22,7 @@ md5.o : src/md5.c
 mrb_md5.o : src/mrb_md5.c
 	@gcc -c $(CFLAGS) src/mrb_md5.c
 
+.PHONY : clean
 clean :
 	-$(RM_F) src/*.o
+	@echo "Gem '$(GEMNAME)' is clean"