Improved Makefile to be able to flash

subtle mod in main.c comment

examples/esp8266/Makefile

@@ -1,13 +1,28 @@
 THISDIR = $(realpath $(CURDIR))
 ROOTDIR = $(realpath $(CURDIR)/../..)
+DOCKER ?= docker run --rm $(DA) -v $(ROOTDIR):$(ROOTDIR) -w $(THISDIR) docker.io/mdashnet/8266
+CMD ?= make -C src defconfig app
+PORT ?= /dev/ttyUSB0
 
 all: example
 
 example:
 	true
 
-build: src/main/main.c src/main/wifi.c Makefile
-	docker run --rm -v $(ROOTDIR):$(ROOTDIR) -w $(THISDIR) docker.io/mdashnet/8266 make -C src defconfig app
+build: Makefile $(wildcard src/main/*)
+	$(DOCKER) $(CMD)
+
+flash:
+flash: CMD = python /esp/components/esptool_py/esptool/esptool.py \
+	--chip esp8266 --port $(PORT) --baud 115200 --before default_reset \
+	--after hard_reset write_flash -z --flash_mode dio --flash_freq 40m \
+	--flash_size 2MB 0x10000 $(THISDIR)/src/build/mongoose-example.bin
+flash: DA = --device $(PORT)
+flash: build
+
+.PHONY: build
 
 clean:
-	rm -rf build
+clean: CMD = rm -rf src/build	
+clean: build
+