got an interrupt-based uart interface library working
diff --git a/bbb_cape/src/cape/util.h b/bbb_cape/src/cape/util.h
new file mode 100644
index 0000000..b374ac8
--- /dev/null
+++ b/bbb_cape/src/cape/util.h
@@ -0,0 +1,11 @@
+#ifndef CAPE_UTIL_H_
+#define CAPE_UTIL_H_
+
+#define ALIAS_WEAK(f) __attribute__ ((weak, alias (#f)))
+
+// Prevents the compiler from reordering memory operations around this.
+static inline void compiler_memory_barrier(void) {
+ __asm__ __volatile__("" ::: "memory");
+}
+
+#endif // CAPE_UTIL_H_