use bigger blocksize

target/arm/Makefile

@@ -162,7 +162,7 @@ ifeq ($(ADK_TARGET_FS),genimage)
 targethelp:
 	@echo "The disk image is: $(FW_DIR)/sdcard.img"
 	@echo "Use following command to install it on SD card:"
-	@echo 'sudo dd if=$(FW_DIR)/sdcard.img of=/dev/sdX bs=2048k'
+	@echo 'sudo dd if=$(FW_DIR)/sdcard.img of=/dev/sdX bs=32M'
 endif
 
 kernel-strip: