make: raise oversize alert if overlay size is less than 128KB

Author: themactep

Makefile

@@ -114,6 +114,7 @@ FIRMWARE_NOBOOT_SIZE = $(shell echo $$(($(FLASH_SIZE) - $(U_BOOT_PARTITION_SIZE)
 # dynamic partitions
 OVERLAY_SIZE = $(shell echo $$(($(FLASH_SIZE) - $(OVERLAY_OFFSET))))
 OVERLAY_SIZE_NOBOOT = $(shell echo $$(($(FIRMWARE_NOBOOT_SIZE) - $(OVERLAY_OFFSET_NOBOOT))))
+OVERLAY_MINUMUM_SIZE := 131072
 
 # partition offsets
 U_BOOT_OFFSET = 0
@@ -214,7 +215,7 @@ delete_bin_update:
 	if [ -f $(FIRMWARE_BIN_NOBOOT) ]; then rm $(FIRMWARE_BIN_NOBOOT); fi
 
 create_overlay: $(U_BOOT_BIN)
-	if [ $(OVERLAY_SIZE) -lt 0 ]; then $(FIGLET) "OVERSIZE"; fi
+	if [ $(OVERLAY_SIZE) -lt $(OVERLAY_MINUMUM_SIZE) ]; then $(FIGLET) "OVERSIZE"; fi
 	if [ -f $(OVERLAY_BIN) ]; then rm $(OVERLAY_BIN); fi
 	$(OUTPUT_DIR)/host/sbin/mkfs.jffs2 --little-endian --pad=$(OVERLAY_SIZE) \
 		--root=$(BR2_EXTERNAL)/overlay/upper/ --eraseblock=$(ALIGN_BLOCK) \