[BOOT] Multiboot compliant kernel which runs 64 bit code

Makefile

@@ -4,12 +4,24 @@ ifeq ($(MITTOS64),)
   $(error Build environment is not activated. Please source activate)
 endif
 
-.PHONY: all clean
+.PHONY: all clean kernel
 SHELL := bash
 
-all:
+CC=$(TARGET)-gcc
+FLAGS_TO_PASS:= \
+	CC=$(CC)
+
+all: kernel
+
+# A trick to only build phony target if necessary
+kernel:
+ifeq ($(shell make -sqC kernel || echo 1), 1)
+	@(. util/helpers.sh; print_info "Building kernel")
+	$(MAKE) -C kernel install $(FLAGS_TO_PASS)
+endif
 
 clean:
 	@(. util/helpers.sh; print_info "Cleaning up")
+	$(MAKE) -C kernel clean
 	rm -f mittos64.iso
 	rm -f qemu-error.log