Update Makefile

src/Makefile

@@ -1,14 +1,15 @@
 EXEC := bringelle
 CC := gcc -c -m32 -fno-pie -fno-builtin -fno-stack-protector
 
-UTILS_OBJ := $(addsuffix .o,$(basename $(wildcard utils/*.c)))
+BOOT_OBJ := $(addsuffix .o,$(basename $(shell find ./boot -name "*.[c|S]")))
+UTILS_OBJ := $(addsuffix .o,$(basename $(shell find ./utils -name "*.[c|S]")))
 
 all: $(EXEC)
 
-$(EXEC): boot/boot.o $(UTILS_OBJ) bringelle.o
+$(EXEC): $(BOOT_OBJ) $(UTILS_OBJ) bringelle.o
 	ld -Ttext=0x00100000 -melf_i386 -nostdlib --oformat=binary -o bringelle $^ 
 
-boot/boot.o: ./boot/boot.S
+%.o: %.S
 	as --32 -o $@ $^ -mx86-used-note=no
 
 %.o: %.c
@@ -16,8 +17,8 @@ boot/boot.o: ./boot/boot.S
 	objcopy --remove-section .note.gnu.property $@
 
 clean:
-	- rm $(EXEC)
-	- find ./ -name "*.o" -delete
+	rm -f $(EXEC)
+	find ./ -name "*.o" -delete
 
 .PHONY: clean