1 files changed, 22 insertions, 0 deletions
diff --git a/firmware/mac.h b/firmware/mac.h
new file mode 100644
index 0000000..26aaff6
--- /dev/null
+++ b/firmware/mac.h
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+#ifndef __MAC_H__
+#define __MAC_H__
+
+#include <unistd.h>
+
+/* Device MAC address.
+ *
+ * 32 bits might seem a little short for a device MAC, but at 20 bus nodes the probablility of a collision is about 1 in
+ * 10 million. Check for yourself using the python code below.
+ *
+ *     #!/usr/bin/env python3
+ *     from operator import mul
+ *     from functools import reduce
+ *     m = 32
+ *     n = 20
+ *     print(reduce(mul, [2**m-i for i in range(n)]) / ((2**m)**n))
+ *     # -> 0.9999999557621786
+ */
+
+extern uint32_t device_mac;
+
+#endif /* __MAC_H__ */