start the Makefile.. some basic arm building, and python test running..

Makefile

@@ -1,4 +1,26 @@
-ARMCC = arm-none-eabi-gcc
+ARMCC?= arm-none-eabi-gcc
+ARMTARGET?= -mcpu=cortex-m3 -mthumb -DSTROBE_SINGLE_THREAD=1
+
+CFLAGS = -Istrobe
+CFLAGS+= -DNDEBUG
+
+SRCS = \
+	strobe/strobe.c strobe/x25519.c
+
+.OBJDIR = build
+
+.PHONY: all
+all: $(BUILDDIR)/strobe.o $(BUILDDIR)/x25519.o
+
+.PHONY: runtests
+runtests:
+	ls *.py | entr sh -c 'python -m coverage run -m unittest lora && coverage report --omit=p/\* -m -i'
+
+$(BUILDDIR):
+	mkdir -p $@
+
+$(BUILDDIR)/%.o : %.c
+	$(ARMCC) $(ARMTARGET) $(CFLAGS) -c $< -o $@
 
 STROBE_REPO = https://git.code.sf.net/p/strobe/code
 STROBE_BRANCH = master