Fix caching in Makefile

Makefile

@@ -17,56 +17,62 @@ endif
 # Function to print status messages
 print_status = $(ECHO) "\033[34m--- $1\033[0m"
 
-.PHONY: all build assemble apply-patches copy-submodule update-submodule convert-line-endings init-submodule create-patch clean
+
+.PHONY: all build assemble apply-patches copy-submodule create-patch clean
+
 
 all: build
 
 ## Submodule management
 
-init-submodule:
-	@$(call print_status, Initializing submodule)
+$(BUILD_DIR)/.has_submodule:
+	@$(call print_status, Copying submodule)
 	@if [ -d "$(SUBMODULE_DIR)" ] && [ -z "$$(ls -A $(SUBMODULE_DIR))" ]; then \
 		git submodule update --init --recursive; \
-	else \
-		echo "Submodule directory is not empty, skipping initialization"; \
 	fi
-
-copy-submodule: init-submodule
-	@$(call print_status, Copying submodule)
 	mkdir -p $(BUILD_DIR)
 	cp -r $(SUBMODULE_DIR)/* $(BUILD_DIR)/
+	@touch $(BUILD_DIR)/.has_submodule
+
+copy-submodule: $(BUILD_DIR)/.has_submodule
 
 ## Patch management
 
-convert-line-endings:
+$(BUILD_DIR)/.is_patched: $(BUILD_DIR)/.has_submodule
 	@$(call print_status, Converting line endings)
 	find $(BUILD_DIR) -type f \( -name '*.c' -o -name '*.h' \) -exec sed -i "s/\r\$$//" {} +
-
-apply-patches: copy-submodule convert-line-endings
 	@for patch in $(sort $(wildcard $(PATCH_DIR)/*.patch)); do \
 		$(call print_status, Applying $$patch); \
 		patch -d $(BUILD_DIR) -p1 < $$patch; \
 	done
+	@touch $(BUILD_DIR)/.is_patched
+
+apply-patches: $(BUILD_DIR)/.is_patched
 
 create-patch:
 	@$(call print_status, Creating patch)
 	./scripts/create_patch.sh
 
-assemble: apply-patches
+## Source management
+
+$(BUILD_DIR)/.is_assembled: $(BUILD_DIR)/.is_patched
 	@$(call print_status, Assembling source)
 	cp -r $(SRC_DIR)/* $(BUILD_DIR)/
+	@touch $(BUILD_DIR)/.is_assembled
+
+assemble: $(BUILD_DIR)/.is_assembled
 
 ## Build targets
 
-$(BUILD_DIR)/retroarch:
+$(BUILD_DIR)/retroarch: $(BUILD_DIR)/.is_assembled
 	@$(call print_status, Building for Miyoo Mini)
 	@cd $(BUILD_DIR) && make -f Makefile.miyoomini PACKAGE_NAME=retroarch
 
-$(BUILD_DIR)/retroarch_miyoo354:
+$(BUILD_DIR)/retroarch_miyoo354: $(BUILD_DIR)/.is_assembled
 	@$(call print_status, Building for Miyoo 354)
 	@cd $(BUILD_DIR) && make -f Makefile.miyoomini MIYOO354=1 PACKAGE_NAME=retroarch_miyoo354
 
-build: assemble $(BUILD_DIR)/retroarch $(BUILD_DIR)/retroarch_miyoo354
+build: $(BUILD_DIR)/retroarch $(BUILD_DIR)/retroarch_miyoo354
 	@$(call print_status, Copying binaries)
 	mkdir -p bin
 	cp $(BUILD_DIR)/retroarch bin/