start sink

sink/Makefile

@@ -0,0 +1,21 @@
+BUILD_DIR = build
+
+C_SOURCES = \
+  ../cube/User/Src/sha256.c \
+  sink20169.c
+
+C_INCLUDES = \
+  -I../cube/User/Inc
+
+CC = gcc
+CFLAGS = $(C_INCLUDES) -Wall -Werror
+LDFLAGS =
+
+OBJECTS = $(addprefix $(BUILD_DIR)/,$(notdir $(C_SOURCES:.c=.o)))
+vpath %.c $(sort $(dir $(C_SOURCES)))
+
+$(BUILD_DIR)/%.o: %.c Makefile | $(BUILD_DIR)
+	$(CC) -c $(CFLAGS) $< -o $@
+
+$(BUILD_DIR)/sink20169: $(OBJECTS) Makefile
+	$(CC) $(OBJECTS) $(LDFLAGS) -o $@

sink/sink20169.c

@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+int main() {
+    printf("Hello world!\n");
+}