firmware: Add 64 bit MAC to shell prompt

This demonstrates that the readout of the 64 bit MAC address from the
STM32WL55 microcontroller works and is useful to recognize used devices.

1 files changed, 41 insertions, 0 deletions

diff --git a/firmware/src/uid64.c b/firmware/src/uid64.c
new file mode 100644
index 0000000..984b7fe
--- /dev/null
+++ b/firmware/src/uid64.c
@@ -0,0 +1,41 @@
+#include <stdio.h>
+
+#include <zephyr/devicetree.h>
+
+#include "uid64.h"
+
+#define UID64_NODE DT_NODELABEL(uid64)
+
+uint64_t uid64_get(void) {
+#if DT_NODE_EXISTS(UID64_NODE)
+		return *(volatile uint64_t *) DT_REG_ADDR(UID64_NODE);
+#else
+		return 0;
+#endif
+}
+
+void uid64_to_string(uint64_t uid, char *str) {
+	uint8_t *source = (uint8_t *)&uid + 7;
+	char *sink = str;
+
+	for (unsigned int i = 0; i < 8; i++) {
+		/* delimiter */
+		if (i > 0) {
+			*sink = ':';
+			sink++;
+		}
+
+		/* byte values */
+		snprintf(sink, 3, "%02x", *source);
+		source--;
+		sink += 2;
+	}
+}
+
+bool uid64_available(void) {
+#if DT_NODE_EXISTS(UID64_NODE)
+	return true;
+#else
+	return false;
+#endif
+}