Commenting and cleanup

src/kernel/Makefile

@@ -2,12 +2,11 @@ ifeq ($(MITTOS64),)
 $(error Unsupported environment! See README)
 endif
 
-CC := x86_64-elf-gcc
-
 SRC := $(wildcard **/*.[cS])
 OBJ := $(patsubst %, %.o, $(basename $(SRC)))
 
-CFLAGS := -Wall -Wextra -pedantic -ffreestanding
+CFLAGS ?= -Wall -Wextra -pedantic
+CFLAGS += -ffreestanding
 CFLAGS += -ggdb -O0
 ASFLAGS += -ggdb
 CPPFLAGS += -I include
@@ -16,7 +15,8 @@ LDFLAGS := -n -nostdlib -lgcc -T Link.ld
 kernel: $(OBJ)
 	$(LINK.c) $^ -o $@
 
-
+# Automatically generate dependency files
+# Those keep track of which header files are used by which source files
 DEP := $(OBJ:.o=.d)
 DEPFLAGS = -MT $@ -MMD -MP -MF $*.d
 $(OBJ): CPPFLAGS += $(DEPFLAGS)
@@ -33,6 +33,7 @@ install: $(DESTDIR)$(PREFIX)/kernel
 clean:
 	rm -rf $(OBJ) $(DEP) kernel
 
-.PHONY: install
+.PHONY: install clean
 
+# Include generated dependency files
 include $(DEP)