chore: rework makefile

Makefile

@@ -1,32 +1,26 @@
-TARGET ?= main
+.PHONY: all clean re 
+.DEFAULT_GOAL := all
 
-SRC := $(wildcard src/*.s src/*.asm)
-OBJ := $(SRC:.s=.o)
-OBJ := $(OBJ:.asm=.o)
+SRC		?= $(wildcard src/*.s)
+OBJ		 = $(SRC:.s=.o)
+EXE		?= main
+AS	 	?= as
+LD	 	?= ld
+ASFLAGS ?=
+LDFLAGS	?=
 
-AS = as
-LD = ld
-NASM = nasm
-
-ASFLAGS = 
-NASMFLAGS = -f elf64
-LDFLAGS = 
-
-all: $(TARGET) run
+$(EXE): $(OBJ)
+	$(LD) $(LDFLAGS) -o $@ $(OBJ)
 
 %.o: %.s
 	$(AS) $(ASFLAGS) -o $@ $<
 
-%.o: %.asm
-	$(NASM) $(NASMFLAGS) -o $@ $<
-
-$(TARGET): $(OBJ)
-	$(LD) $(LDFLAGS) -o $@ $^
+all: $(EXE)
 
 clean:
-	rm -f $(OBJ) $(TARGET)
+	rm -f $(OBJ) $(EXE)
 
 re: clean all
 
-run: $(TARGET)
-	./$(TARGET)
+run: $(EXE)
+	./$(EXE)