Added nanopb generation facilities

src/protocol/Makefile

@@ -0,0 +1,16 @@
+NANOPB_DIR = ../../dependencies/nanopb
+NANOPB_PROTO_DIR = $(NANOPB_DIR)/generator/proto
+
+PROTOC = protoc
+PROTOC_OPTS = --plugin=protoc-gen-nanopb=protoc-gen-nanopb \
+              -I$(NANOPB_PROTO_DIR) -I. --nanopb_out=.
+
+gen: make-nanopb criterion.pb.c
+
+make-nanopb:
+	$(MAKE) -C $(NANOPB_PROTO_DIR)
+
+criterion.pb.c: criterion.proto
+	$(PROTOC) $(PROTOC_OPTS) $<
+
+.PHONY: gen make-nanopb

src/protocol/protoc-gen-nanopb

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# This file is used to invoke nanopb_generator.py as a plugin
+# to protoc on Linux and other *nix-style systems.
+# Use it like this:
+# protoc --plugin=nanopb=..../protoc-gen-nanopb --nanopb_out=dir foo.proto
+#
+# Note that if you use the binary package of nanopb, the protoc
+# path is already set up properly and there is no need to give
+# --plugin= on the command line.
+
+NANOPB_PATH="../../dependencies/nanopb/generator"
+exec python2 "$NANOPB_PATH/nanopb_generator.py" --protoc-plugin