Now supports multiple targets

A makefile has been adde to automate the build process, and put all the
firmware variants in a `dist` directory, ready to use.

Makefile

@@ -0,0 +1,25 @@
+YOTTA=yt
+
+all:	ble400 microbit
+
+ble400: dist .yotta.json
+	$(YOTTA) build --config config/ble400.json
+	cp build/bbc-microbit-classic-gcc/source/ubit-ble-sniffer-combined.hex dist/btlejack-firmware-ble400.hex
+	$(YOTTA) clean
+
+microbit: dist .yotta.json
+	$(YOTTA) build
+	cp build/bbc-microbit-classic-gcc/source/ubit-ble-sniffer-combined.hex dist/btlejack-firmware-microbit.hex
+	$(YOTTA) clean
+
+dist:
+	@mkdir -p dist
+	@rm dist/* -rf
+
+.yotta.json:
+	$(YOTTA) target bbc-microbit-classic-gcc
+
+clean:
+	$(YOTTA) clean
+	rm dist/ -rf
+	rm .yotta.json

config/ble400.json

@@ -0,0 +1,4 @@
+{
+	"rxpin": "P0_9",
+	"txpin": "P0_11"
+}

source/main.cpp

@@ -2093,6 +2093,14 @@ int main() {
 
     /* Initalize Micro:Bit and serial link. */
     uBit.init();
+
+#ifdef YOTTA_CFG_TXPIN
+  #ifdef YOTTA_CFG_RXPIN
+    #pragma message("Btlejack firmware will use custom serial pins")
+    uBit.serial.redirect(YOTTA_CFG_TXPIN, YOTTA_CFG_RXPIN);
+  #endif
+#endif
+
     pLink = new Link(&uBit);
 
     /* Init BLE timer. */