From 0b8c448b300da233de8b8d4fcdb359ec0679a513 Mon Sep 17 00:00:00 2001
From: Travis La Marr <exiva@exiva.net>
Date: Fri, 15 Jul 2016 10:28:23 -0400
Subject: [PATCH] Make DFU wait for bootloader

Added a loop for waiting for the keyboard to be put in bootloader mode,
rather than failing out. Makes building keymaps easier.
---
 tmk_core/avr.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tmk_core/avr.mk b/tmk_core/avr.mk
index 3bf2b34f88..6c03e1650e 100644
--- a/tmk_core/avr.mk
+++ b/tmk_core/avr.mk
@@ -107,6 +107,10 @@ flip: $(BUILD_DIR)/$(TARGET).hex
 	batchisp -hardware usb -device $(MCU) -operation start reset 0
 
 dfu: $(BUILD_DIR)/$(TARGET).hex sizeafter
+	until dfu-programmer $(MCU) get bootloader-version; do\
+		echo "Error: Bootloader not found. Trying again in 5s." ;\
+		sleep 5 ;\
+	done
 ifneq (, $(findstring 0.7, $(shell dfu-programmer --version 2>&1)))
 	dfu-programmer $(MCU) erase --force
 else