Improved build commands

src/kernel/Makefile

@@ -1,5 +1,8 @@
+ifeq ($(BUILDROOT),)
+$(error BUILDROOT IS NOT SET!)
+endif
 
-CC := x86_64-elf-gcc
+CC := ${TARGET}-gcc
 
 SRC := $(wildcard **/*.[cS])
 OBJ := $(patsubst %, %.o, $(basename $(SRC)))
@@ -13,6 +16,7 @@ LDFLAGS := -n -nostdlib -lgcc -T Link.ld
 kernel: $(OBJ)
 	$(LINK.c) $^ -o $@
 
+# Automatic dependency tracking
 DEP := $(OBJ:.o=.d)
 DEPFLAGS = -MT $@ -MMD -MP -MF $*.d
 $(OBJ): CPPFLAGS += $(DEPFLAGS)
@@ -30,4 +34,5 @@ clean:
 
 .PHONY: install
 
+# Include automatic dependency rules
 include $(DEP)